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Introduction: Breast density is one of the strongest risk factors for breast cancer, but determinants of breast density in young women remain largely unknown.Methods: Associations of height, adiposity and body fat distribution with percentage dense breast

Space-based Earth observation (EO), in the form of long-term climate data records, has been crucial in the monitoring and quantification of slow changes in the climate system—from accumulating greenhouse gases (GHGs) in the atmosphere, increasing surface temperatures, and melting sea-ice, glaciers and ice sheets, to rising sea-level. In addition to documenting a changing climate, EO is needed for effective policy making, implementation and monitoring, and ultimately to measure progress and achievements towards the overarching goals of the United Nations Framework Convention on Climate Change (UNFCCC) Paris Agreement to combat climate change. The best approach for translating EO into actionable information for policymakers and other stakeholders is, however, far from clear. For example, climate change is now self-evident through increasingly intense and frequent extreme events—heatwaves, droughts, wildfires, and flooding—costing human lives and significant economic damage, even though single events do not constitute “climate”. EO can capture and visualize the impacts of such events in single images, and thus help quantify and ultimately manage them within the framework of the UNFCCC Paris Agreement, both at the national level (via the Enhanced Transparency Framework) and global level (via the Global Stocktake). We present a transdisciplinary perspective, across policy and science, and also theory and practice, that sheds light on the potential of EO to inform mitigation, including sinks and reservoirs of greenhouse gases, and adaptation, including loss and damage. Yet to be successful with this new mandate, EO science must undergo a radical overhaul: it must become more user-oriented, collaborative, and transdisciplinary; span the range from fiducial to contextual data; and embrace new technologies for data analysis (e.g., artificial intelligence). Only this will allow the creation of the knowledge base and actionable climate information needed to guide the UNFCCC Paris Agreement to a just and equitable success.

Purpose: To assess associations of theoretically reallocating time from sleep, sedentary behavior, or light intensity physical activity (LPA) to moderate/vigorous intensity physical activity (MVPA) during pregnancy with infant growth outcomes., Methods: We used data from a cohort of pregnant individuals with overweight or obesity (n = 116). At 9-15 and 30-36 weeks gestation, waking movement was measured using wrist-worn accelerometers and sleep duration was self-reported. Outcomes were obtained from delivery electronic health records (birth) and study visits (12 months). We used compositional isotemporal substitution models., Results: In early pregnancy, reallocating 10 minutes of sleep, sedentary behavior, or LPA to MVPA was associated with 20% (RR = 0.80; 95%CI: 0.75,0.85), 21% (RR = 0.79; 95%CI: 0.75,0.84), and 25% (RR = 0.75; 95%CI: 0.70,0.81) lower risk of large-for-gestational age (LGA) birthweight, respectively, and 17% (RR = 0.83; 95%CI: 0.75,0.91), 18% (RR = 0.82; 95%CI: 0.75,0.91), and 22% (RR = 0.78; 95%CI: 0.70,0.88) lower risk of rapid infant growth (birth to 12 months), respectively. In late pregnancy, reallocating 10 minutes to MVPA was associated with 18% to 22% lower risk of LGA birthweight, but was not associated with rapid infant growth. Reallocating time to MVPA in early or late pregnancy was not associated with high newborn body fat percent., Conclusions: Our findings suggest beneficial associations of theoretically reallocating time from sleep, sedentary behavior, or LPA to MVPA, especially during early pregnancy, for reducing LGA birthweight and rapid infant growth., Competing Interests: Conflict of Interest and Funding Source: This work was supported by grants from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (K99HD100585, R01HD073572). The authors have no relevant conflicts of interest to disclose., (Copyright © 2024 by the American College of Sports Medicine.)

Physical activity (PA), sedentary behavior (SB), and sleep are each individually associated with falls and fractures, but often are not examined simultaneously. Compositional data analysis examined the combined prospective associations between the proportion of time in PA, SB, and sleep relative to the remaining behaviors with recurrent falls (2+ falls in any year), any fractures, and major osteoporotic fracture (MOF) from tri-annual questionnaires, with adjudication for fractures, in 2918 older men aged 78.9 ± 5.1 years in the Osteoporotic Fractures in Men (MrOS) Study. Accelerometers were worn on the right tricep for seven consecutive 24-hour periods and measured PA (>1.5 METs), SB (≤1.5 METs), and sleep. Generalized Estimating Equations evaluated associations with recurrent falls. Cox proportional hazards regression estimated any incident fracture and MOF risk separately. Over four years of follow-up 1025 (35.2%) experienced recurrent falls; over 10 ± 4 years of follow-up, 669 (22.9%) experienced incident fractures and 370 (12.7%) experienced a MOF. Higher proportions of PA relative to SB and sleep were associated with a lower odds of recurrent falls [Odds Ratio (OR): 0.87, 95% CI: 0.76-0.99]. Higher proportions of SB relative to PA and sleep were associated with a higher odds of recurrent falls (OR: 1.38, 95% CI: 1.06-1.81) and higher risk of any fracture [Hazard Ratio (HR): 1.42, 95% CI: 1.05-1.92]. Higher proportions of sleep relative to PA and SB were associated with a lower risk of fracture (HR: 0.74, 95% CI: 0.54-0.99). No associations of activity composition with MOF were observed. When accounting for the co-dependence of daily activities, higher proportions of SB relative to the proportion of PA and sleep were associated with higher odds of recurrent falls and fracture risk. Results suggest reducing SB (and increasing PA) may lower fall and fracture risk in older men, which could inform future interventions., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society for Bone and Mineral Research.)

Objective: This study aimed to evaluate the prospective associations of baseline personal characteristics with utilization frequency and expenditure of chiropractic care in US adults (≥18 years)., Methods: Data are from the 1358 respondents to the 2014 to 2016 Medical Expenditure Panel Survey who utilized chiropractic care. Individual, familial, health-related, and behavioral factors were included as covariates in the multivariate analytic model. Poisson and multinominal logistic regressions were modeled to examine the associations between the predictors and chiropractic utilization and expenditure., Results: The mean annual number of visits was 8.2 visits (95% confidence interval [CI]: 7.9, 8.5), with annual expenditure of $677.43 U.S. dollars (95% CI: $595.47-$759.39) and $84.84 (95% CI: $77.89-$91.78) per visit. Female sex was associated with a 19% higher number of visits (rate ratio [RR] = 1.19, 95% CI: 1.01, 1.41) than males. Publicly insured and uninsured were associated with a 44% higher (RR = 1.44, 95% CI: 1.14, 1.82) and 36% lower (RR = 0.64, 95% CI: 0.48, 0.86) visit frequency, respectively, than those privately insured. Rheumatoid arthritis was associated with 7.38 times the risk of high expenditure (95% CI: 2.61, 24.67) than medium expenditure, compared to no arthritis. Relative to physically active individuals, physical inactivity was associated with a 27% higher visit frequency (RR = 1.27, 95% CI: 1.09, 1.49) and an 82% higher risk (relative risk ratio = 1.82, 95% CI: 1.05, 3.14) of high expenditure than low expenditure., Conclusion: This analysis found distinct usage and expenditure patterns that vary according to specific baseline predictors. Female sex, being publicly insured, having rheumatoid arthritis, and physically inactive were associated with variance in expenditure. Results from this study may help identify chiropractic patients with tendencies for higher utilization or spending and may indirectly assist in predicting patients with slower response to care., (Copyright © 2024. Published by Elsevier Inc.)

Objective: This study aimed to examine the trends in the utilization and expenditure of chiropractic care in a representative sample of US adults, aged ≥18 years., Methods: Serial cross-sectional data (2007-2016) from the Medical Expenditure Panel Survey (MEPS) were examined. Weighted descriptive statistics were analyzed to obtain national estimates of chiropractic utilization and expenditure, and time-series linear regression was used to assess trends over time. Socio-demographic characteristics and musculoskeletal diagnoses associated with chiropractic use were also reported., Results: A statistically significantly increasing trend was observed for the number of adults receiving chiropractic care (p < .05), number of visits (p < .05) and utilization rate (P < .05) from 2007 to 2016. A similar trend was not found for chiropractic expenditure during this period (P > .05). The mean number of visits was 8.3 visits per year, with a mean expenditure of $86.94 USD per visit and $721.43 USD per person per year. Mean age of adult chiropractic users each year ranged between 48.6 and 51.2 years old, and users were primarily female (56.3%-60.4%), White persons (90.1%-93.5%), and privately insured (77.3%-82.8%). The most prevalent musculoskeletal diagnoses associated with chiropractic use were low back conditions (45.4%-58.1%), inflammatory/degenerative disc or joint conditions (21.2%-26.8%) and head and neck complaints (9.8%-13.7%)., Conclusion: The findings showed statistically significant increasing trends for the number of adult chiropractic users, the number of visits, and percent utilization of chiropractic care from 2007 to 2016. Conversely, we found a statistically null trend for the total annual expenditure on chiropractic care during the same time period. Findings from this analysis imply that, while chiropractic care appears to be growing, it may still be under-utilized, and more efforts should be devoted to ensuring sustained growth and a larger role in the management of musculoskeletal health., (Copyright © 2024. Published by Elsevier Inc.)

Aims: Moderate-to-vigorous-intensity physical activity (MVPA), cardiorespiratory fitness (CRF), and coronary artery calcification (CAC) are associated with cardiovascular disease (CVD) risk. While a U-shaped relationship between CRF or MVPA and CAC has been reported, the presence of CAC among highly fit individuals might be benign. We examined interactive associations of CRF or MVPA and CAC with outcomes and evaluated the relationship of CRF and MVPA to CAC incidence., Methods: CARDIA participants with CAC assessed in 2005-06 were included (n=3,141, mean age 45). MVPA was assessed by self-report and accelerometer. CRF was estimated with a maximal graded exercise test. Adjudicated CVD events and mortality data were obtained through 2019. CAC was reassessed in 2010-11. Cox models were constructed to assess hazard ratios (HRs) for CVD, coronary heart disease (CHD), and mortality in groups defined by CAC presence/absence and lower/higher CRF or MVPA levels. Logistic models were constructed to assess associations with CAC incidence. Adjustment was made for sociodemographic and CVD risk factors., Results: Relative to participants with no CAC and higher CRF, the adjusted HRs for CVD were 4.68 for CAC and higher CRF, 2.22 for no CAC and lower CRF, and 3.72 for CAC and lower CRF. For CHD, the respective HRs were 9.98, 2.28, and 5.52. For mortality, the HRs were 1.15, 1.58, and 3.14, respectively. Similar findings were observed when MVPA, measured either by self-report or accelerometer, was substituted for CRF. A robust inverse association of CRF and accelerometer-derived MVPA with CAC incidence was partly accounted for by adjusting for CVD risk factors., Conclusions: In middle-aged adults, CRF and MVPA demonstrated an inverse association with CAC incidence but did not mitigate the increased cardiovascular risk associated with CAC, indicating that CAC is not benign in individuals with higher CRF or MVPA levels., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: Cardiovascular health (CVH) in young adulthood (YA) has been associated with cardiovascular outcomes in older age. However, little is known about the relationship between YA CVH and mid-life blood pressure (BP) trajectories., Methods: Baseline CVH (defined by 7 of the American Heart Association's [AHA] Life's Essential 8 [LE8] metrics, excluding BP) was measured in YA with individual metrics scored and averaged as a composite LE8 score. Categorical CVH status was defined as high, moderate, and low. Latent class analysis was used to identify trajectories of mid-BP (mean of systolic blood pressure [SBP] and diastolic blood pressure [DBP]) from average ages 35 to 55 years. Multinomial logistic regression was used to estimate the association of YA CVH status (continuously and categorically) with mid-life BP trajectory group membership., Results: There were 3,688 participants from the Coronary Artery Risk Development in Young Adults (CARDIA) study in YA with follow-up data for mid-life BP trajectories. We observed 3 BP trajectory groups, labeled as Persistently-Low, Middle, and High-Increasing. On average, each 10-points higher baseline LE8 score (mean [SD] of 73.5 [13.1]) in YA was associated with adjusted odds ratios of 0.78 (95% CI, 0.72-0.84) for membership in the Middle and 0.65 (0.57-0.73) for membership in the High-Increasing trajectory groups. Compared with categorical low CVH status at baseline, those with high CVH were significantly less likely to be in the Middle and High-Increasing BP trajectory groups., Conclusions: Moderate or low CVH status in YA is associated with elevated mid-life BP trajectory. These data suggest that young adult CVH promotion may be important for the primordial prevention of hypertension., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Journal of Hypertension, Ltd. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: Proximity to urban blue and green spaces has been associated with improved cardiovascular health; however, few studies have examined the role of race and socioeconomic status in these associations., Methods: Data were from the CARDIA study (Coronary Artery Risk Development in Young Adults). We included longitudinal measurements (1985-1986 to 2010-2011) of blue and green spaces, including percentage of blue space cover, distance to the nearest river, green space cover, and distance to the nearest major park. Presence of coronary artery calcification (CAC) was measured with noncontrast cardiac computed tomography in 2010 to 2011. The associations of blue and green spaces with CAC were assessed with generalized estimating equation regression with adjustment for demographics, individual and neighborhood socioeconomic status, health-related behaviors, and other health conditions. We conducted stratified analyses by race and neighborhood deprivation score to investigate whether the association varied according to social determinants of health., Results: The analytic sample included 1365 Black and 1555 White participants with a mean±SD age of 50.1±3.6 years. Among Black participants, shorter distance to a river and greater green space cover were associated with lower odds of CAC (per interquartile range decrease [1.45 km] to the river: odds ratio [OR], 0.90 [95% CI, 0.84-0.96]; per 10 percentage-point increase of green space cover: OR, 0.85 [95% CI, 0.75-0.95]). Among participants in deprived neighborhoods, greater green space cover was associated with lower odds of CAC (per a 10 percentage-point increase: OR, 0.89 [95% CI, 0.80-0.99]), whereas shorter distance to the park was associated with higher odds of CAC (per an interquartile range decrease [5.3 km]: OR, 1.07 [95% CI, 1.00-1.15]). Black participants in deprived neighborhoods had lower odds of CAC with shorter distance to a river (per an interquartile range decrease: OR, 0.90 [95% CI, 0.82-0.98]) and greater green space cover (per a 10 percentage-point increase: OR, 0.85 [95% CI, 0.75-0.97]). There was no statistical interaction between the blue and green spaces and race or neighborhood characteristics in association with CAC., Conclusions: Longitudinally, shorter distance to a river and greater green space cover were associated with less CAC among Black participants and those in deprived neighborhoods. Shorter distance to a park was associated with increased odds of CAC among participants in deprived neighborhoods. Black participants residing in more deprived neighborhoods showed lower odds of CAC in association with greater exposure to river and green space cover., Competing Interests: None.

Importance: Prior cross-sectional studies have suggested that very high levels of physical activity (PA) are associated with a higher prevalence of coronary artery calcium (CAC). However, less is known regarding the association between high-volume PA and progression of CAC over time., Objective: To explore the association between PA (measured at baseline and during follow-up) and the progression of CAC over time., Design, Setting, and Participants: This cohort study included data from 8771 apparently healthy men and women 40 years and older who had multiple preventive medicine visits at the Cooper Clinic (Dallas, Texas), with a mean (SD) follow-up time of 7.8 (4.7) years between the first and last clinic visit. Participants with reported PA and CAC measurements at each visit during 1998 to 2019 were included in the study. Data were analyzed from March 2023 to February 2024., Exposures: PA reported at baseline and follow-up, examined continuously per 500 metabolic equivalent of task minutes per week (MET-min/wk) and categorically: less than 1500, 1500 to 2999, 3000 or more MET-min/wk., Main Outcomes and Measures: Negative binomial regression was used to estimate the rate of mean CAC progression between visits, with potential modification by PA volume, calculated as the mean of PA at baseline and follow-up. In addition, proportional hazards regression was used to estimate hazard ratios for baseline PA as a predictor of CAC progression to 100 or more Agatston units (AU)., Results: Among 8771 participants, the mean (SD) age at baseline was 50.2 (7.3) years for men and 51.1 (7.3) years for women. The rate of mean CAC progression per year from baseline was 28.5% in men and 32.1% in women, independent of mean PA during the same time period. That is, the difference in the rate of CAC progression per year was 0.0% per 500 MET-min/wk for men and women (men: 95% CI, -0.1% to 0.1%; women: 95% CI, -0.4% to 0.5%). Moreover, baseline PA was not associated with CAC progression to a clinically meaningful threshold of 100 AU or more over the follow-up period. The hazard ratio for a baseline PA value of 3000 or more MET-min/wk vs less than 1500 MET-min/wk to cross this threshold was 0.84 (95% CI, 0.66 to 1.08) in men and 1.16 (95% CI, 0.57 to 2.35) in women., Conclusions and Relevance: This study found that PA volume was not associated with progression of CAC in a large cohort of healthy men and women who were initially free of overt cardiovascular disease.

Introduction: Higher levels of perceived stress are associated with adverse cardiovascular health. It is plausible that these associations are attenuated among individuals with positive psychological factors such as social support and health-enhancing behaviors. Therefore, this study examined longitudinal associations of chronic stress with cardiovascular disease (CVD) events, and whether social support and physical activity (PA) modify these associations., Methods: Data from 3,401 adults (mean age 40.2 years; 46.7% Black; 56.2% women) from the Coronary Artery Risk Development in Young Adults (CARDIA) study, with no prior CVD event in 2000-2001 were analyzed. Chronic stress lasting ≥6 months across 5 life domains (work, financial, relationships, health of self, and health of close other) was self-reported. Adjudicated CVD events (fatal/or nonfatal CVD event) were ascertained yearly through 2020. PA and social support were self-reported via questionnaires. Statistical analyses were conducted in 2023 using multivariable stepwise Accelerated Failure Time analysis to assess associations between key study variables., Results: The mean chronic stress score was 1.30±1.33 stressors and, by 2020, 220 participants had experienced a CVD event. Chronic stress was associated with lowered survival (time ratio: 0.92; 95% CI: 0.854-0.989), when adjusted for sociodemographic and lifestyle variables but no longer significant when adjusting for clinical factors. Neither PA nor social support were significant modifiers (all ps>0.05)., Conclusions: Chronic stress was associated with the risk of having a CVD event among middle-aged adults, due at least in part to clinical mediators. Studies should continue exploring positive psychosocial and behavioral factors that may modify this association., (Copyright © 2023 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.)

Despite the wide effects of cardiorespiratory fitness (CRF) on metabolic, cardiovascular, pulmonary and neurological health, challenges in the feasibility and reproducibility of CRF measurements have impeded its use for clinical decision-making. Here we link proteomic profiles to CRF in 14,145 individuals across four international cohorts with diverse CRF ascertainment methods to establish, validate and characterize a proteomic CRF score. In a cohort of around 22,000 individuals in the UK Biobank, a proteomic CRF score was associated with a reduced risk of all-cause mortality (unadjusted hazard ratio 0.50 (95% confidence interval 0.48-0.52) per 1 s.d. increase). The proteomic CRF score was also associated with multisystem disease risk and provided risk reclassification and discrimination beyond clinical risk factors, as well as modulating high polygenic risk of certain diseases. Finally, we observed dynamicity of the proteomic CRF score in individuals who undertook a 20-week exercise training program and an association of the score with the degree of the effect of training on CRF, suggesting potential use of the score for personalization of exercise recommendations. These results indicate that population-based proteomics provides biologically relevant molecular readouts of CRF that are additive to genetic risk, potentially modifiable and clinically translatable., (© 2024. The Author(s).)

Objective: Big Data are increasingly used in obesity and nutrition research to gain new insights and derive personalized guidance; however, this data in raw form are often not usable. Substantial preprocessing, which requires machine learning (ML), human judgment, and specialized software, is required to transform Big Data into artificial intelligence (AI)- and ML-ready data. These preprocessing steps are the most complex part of the entire modeling pipeline. Understanding the complexity of these steps by the end user is critical for reducing misunderstanding, faulty interpretation, and erroneous downstream conclusions., Methods: We reviewed three popular obesity/nutrition Big Data sources: microbiome, metabolomics, and accelerometry. The preprocessing pipelines, specialized software, challenges, and how decisions impact final AI- and ML-ready products were detailed., Results: Opportunities for advances to improve quality control, speed of preprocessing, and intelligent end user consumption were presented., Conclusions: Big Data have the exciting potential for identifying new modifiable factors that impact obesity research. However, to ensure accurate interpretation of conclusions arising from Big Data, the choices involved in preparing AI- and ML-ready data need to be transparent to investigators and clinicians relying on the conclusions., (© 2024 The Obesity Society. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)

Objective: To determine the associations between the number of adverse childhood experiences (ACEs) and objectively-measured physical activity (PA) in a population-based, demographically diverse cohort of 9-14-year-olds and to determine which subtypes of ACEs were associated with physical activity levels., Methods: We analyzed data (n = 7046) from the Adolescent Brain Cognitive Development (ABCD) Study 4.0 release at baseline and year 2 follow-up. ACE (cumulative score and subtypes) and physical activity (average Fitbit daily steps assessed at Year 2) were analyzed using linear regression analyses. Covariates included race and ethnicity, sex, household income, parent education, body mass index, study site, twins/siblings, and data collection period., Results: Adjusted models suggest an inverse association between number of ACEs and Fitbit daily steps, with ≥4 (compared to 0) ACEs associated with 567 fewer daily steps (95% CI -902.2, -232.2). Of the ACEs subtypes, emotional abuse (B = -719.3, 95% CI -1430.8, -7.9), physical neglect (B = -423.7, 95% CI -752.8, -94.6), household mental illness (B = -317.1, 95% CI -488.3, -145.9), and household divorce or separation (B = -275.4, 95% CI -521.5, -29.2) were inversely and statistically significant associated with Fitbit daily steps after adjusting for confounders., Conclusions: Our results suggest that there is an inverse, dose-dependent relationship between cumulative number of ACEs and physical activity as measured by daily steps. This work highlights the importance of screening for ACEs among young people at an early age to help identify those who could benefit from interventions or community programs that support increased physical activity., Competing Interests: Declaration of Competing Interest The authors have no conflict to declare., (Copyright © 2024 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.)

Background: Multimorbidity research has focused on the prevalence and consequences of multimorbidity in older populations. Less is known about the accumulation of chronic conditions earlier in the life course., Methods: We identified patterns of longitudinal multimorbidity accumulation using 30 years of data from in-person exams, annual follow-ups, and adjudicated end-points among 4,945 participants of the Coronary Artery Risk Development in Young Adults (CARDIA) study. Chronic conditions included arthritis, asthma, atrial fibrillation, cancer, end stage renal disease, chronic obstructive pulmonary disease, coronary heart disease, diabetes, heart failure, hyperlipidemia, hypertension, and stroke. Trajectory patterns were identified using latent class growth curve models., Results: Mean age (SD) at baseline (1985-6) was 24.9 (3.6), 55% were female, and 51% were Black. The median follow-up was 30 years (interquartile range 25-30). We identified six trajectory classes characterized by when conditions began to accumulate and the rapidity of accumulation: (1) early-fifties, slow, (2) mid-forties, fast, (3) mid-thirties, fast, (4) late-twenties, slow, (5) mid-twenties, slow, and (6) mid-twenties, fast. Compared with participants in the early-fifties, slow trajectory class, participants in mid-twenties, fast were more likely to be female, Black, and currently smoking and had a higher baseline mean waist circumference (83.6 vs. 75.6 cm) and BMI (27.0 vs. 23.4 kg/m 2 ) and lower baseline physical activity (414.1 vs. 442.4 exercise units)., Conclusions: A life course approach that recognizes the heterogeneity in patterns of accumulation of chronic conditions from early adulthood into middle age could be helpful for identifying high risk subgroups and developing approaches to delay multimorbidity progression., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2024.)

Introduction: Considerable research has linked many risk factors to Alzheimer's Disease and Related Dementias (ADRD). Without a clear etiology of ADRD, it is advantageous to rank the known risk factors by their importance and determine if disparities exist. Statistical-based ranking can provide insight into which risk factors should be further evaluated., Methods: This observational, population-based study assessed 50 county-level measures and estimates related to ADRD in 3,155 counties in the U.S. using data from 2010 to 2021. Statistical analysis was performed in 2022-2023. The machine learning method, eXtreme Gradient Boosting, was utilized to rank the importance of these variables by their relative contribution to the model performance. Stratified ranking was also performed based on a county's level of disadvantage. Shapley Additive exPlanations (SHAP) provided marginal contributions for each variable., Results: The top three ranked predictors at the county level were insufficient sleep, consuming less than one serving of fruits/vegetables per day among adults, and having less than a high school diploma. In both disadvantaged and non-disadvantaged counties, demographic variables such as sex and race were important in predicting ADRD. Lifestyle factors ranked highly in non-disadvantaged counties compared to more environmental factors in disadvantaged counties., Conclusions: This ranked list of factors can provide a guided approach to ADRD primary prevention strategies in the U.S., as the effects of sleep, diet, and education on ADRD can be further developed. While sleep, diet, and education are important nationally, differing prevention strategies could be employed based on a county's level of disadvantage., (Copyright © 2023 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.)

Objective: The goal of this study was to investigate associations of reallocations within 24-h movement profiles and changes in cardiometabolic biomarkers from early to late pregnancy., Methods: In 137 individuals with prepregnancy overweight/obesity, waking movement was measured using wrist-worn accelerometers, sleep was self-reported, and biomarkers were measured in fasting serum samples at 12 and 32 weeks' gestation. We used compositional isotemporal substitution models., Results: On average, biomarkers increased 21%-83% across pregnancy. For those with guideline-recommended moderate/vigorous-intensity physical activity (MVPA) in early pregnancy, reallocating 30 min from MVPA to sleep, sedentary behavior, or light-intensity physical activity (LPA) was associated with a 0.6 mmol/L greater increase in total cholesterol (95% CI: -0.1 to 1.2) and a 0.7 mmol/L greater increase in low-density lipoprotein (LDL) cholesterol (95% CI: 0.1 to 1.3) from early to late pregnancy. For those with low MVPA in early pregnancy, reallocating 30 min from sleep, sedentary behavior, or LPA to MVPA was associated with a 0.6 mmol/L lower increase in total cholesterol (95% CI: -1.3 to 0.1) and a 0.8 mmol/L lower increase in LDL cholesterol (95% CI: -1.4 to -0.1) from early to late pregnancy. There were no associations with change in glucose, insulin, homeostatic model assessment for insulin resistance, very low-density lipoprotein, or high-density lipoprotein cholesterol, triglycerides, or free fatty acids., Conclusions: Maintaining or achieving a 24-h movement profile with guideline-recommended amounts of MVPA may be beneficial for reducing pregnancy-induced increases in total and LDL cholesterol., (© 2024 The Obesity Society.)

Habitual physical activity (PA) impacts the plasma proteome and reduces the risk of developing type 2 diabetes (T2D). Using a large-scale proteome-wide approach in Atherosclerosis Risk in Communities study participants, we aimed to identify plasma proteins associated with PA and determine which of these may be causally related to lower T2D risk. PA was associated with 92 plasma proteins in discovery (P < 1.01 × 10-5), and 40 remained significant in replication (P < 5.43 × 10-4). Eighteen of these proteins were independently associated with incident T2D (P < 1.25 × 10-3), including neuronal growth regulator 1 (NeGR1; hazard ratio per SD 0.85; P = 7.5 × 10-11). Two-sample Mendelian randomization (MR) inverse variance weighted analysis indicated that higher NeGR1 reduces T2D risk (odds ratio [OR] per SD 0.92; P = 0.03) and was consistent with MR-Egger, weighted median, and weighted mode sensitivity analyses. A stronger association was observed for the single cis-acting NeGR1 genetic variant (OR per SD 0.80; P = 6.3 × 10-5). Coupled with previous evidence that low circulating NeGR1 levels promote adiposity, its association with PA and potential causal role in T2D shown here suggest that NeGR1 may link PA exposure with metabolic outcomes. Further research is warranted to confirm our findings and examine the interplay of PA, NeGR1, adiposity, and metabolic health., (© 2024 by the American Diabetes Association.)

Background: Combination devices to monitor heart rate/rhythms and physical activity are becoming increasingly popular in research and clinical settings. The Zio XT Patch (iRhythm Technologies, San Francisco, CA, USA) is US Food and Drug Administration (FDA)-approved for monitoring heart rhythms, but the validity of its accelerometer for assessing physical activity is unknown., Objective: To validate the accelerometer in the Zio XT Patch for measuring physical activity against the widely-used ActiGraph GT3X., Methods: The Zio XT and ActiGraph wGT3X-BT (Actigraph, Pensacola, FL, USA) were worn simultaneously in two separately-funded ancillary studies to Visit 6 of the Atherosclerosis Risk in Communities (ARIC) Study (2016-2017). Zio XT was worn on the chest and ActiGraph was worn on the hip. Raw accelerometer data were summarized using mean absolute deviation (MAD) for six different epoch lengths (1-min, 5-min, 10-min, 30-min, 1-h, and 2-h). Participants who had ≥3 days of at least 10 h of valid data between 7 a.m-11 p.m were included. Agreement of epoch-level MAD between the two devices was evaluated using correlation and mean squared error (MSE)., Results: Among 257 participants (average age: 78.5 ± 4.7 years; 59.1% female), there were strong correlations between MAD values from Zio XT and ActiGraph (average r : 1-min: 0.66, 5-min: 0.90, 10-min: 0.93, 30-min: 0.93, 1-h: 0.89, 2-h: 0.82), with relatively low error values (Average MSE × 10 6 : 1-min: 349.37 g , 5-min: 86.25 g , 10-min: 56.80 g , 30-min: 45.46 g , 1-h: 52.56 g , 2-h: 54.58 g )., Conclusions: These findings suggest that Zio XT accelerometry is valid for measuring duration, frequency, and intensity of physical activity within time epochs of 5-min to 2-h.

Importance: Physical activity (PA) is recommended for preventing and treating nonalcoholic fatty liver disease (NAFLD). Yet, how long-term patterns of intensity-based physical activity, including moderate-intensity PA (MPA) and vigorous-intensity PA (VPA), might affect the prevalence of NAFLD in middle age remains unclear., Objective: To identify distinct intensity-based PA trajectories from young to middle adulthood and examine the associations between PA trajectories and NAFLD prevalence in midlife., Design, Setting, and Participants: This population-based cohort of 2833 participants used the Coronary Artery Risk Development in Young Adults study data. The setting included field clinics in Birmingham, Alabama; Chicago, Illinois; Minneapolis, Minnesota; and Oakland, California. Data analysis was completed in March 2023., Exposures: PA was self-reported at 8 examinations over 25 years (1985-1986 to 2010-2011) and separately scored for MPA and VPA., Main Outcomes and Measures: NAFLD was defined as liver attenuation values less than 51 Hounsfield units after exclusion of other causes of liver fat, measured using computed tomography in year 25 (2010-2011)., Results: Among a total of 2833 participants included in the sample, 1379 (48.7%) self-identified as Black, 1454 (51.3%) as White, 1206 (42.6%) as male, and 1627 (57.4%) as female from baseline (1985-1986) (mean [SD] age, 25.0 [3.6] years) to year 25 (2010-2011) (mean [SD] age, 50.1 [3.6] years). Three MPA trajectories were identified: very low stable (1514 participants [53.4%]), low increasing (1096 [38.7%]), and moderate increasing (223 [7.9%]); and 3 VPA trajectories: low stable (1649 [58.2%]), moderate decreasing (1015 [35.8%]), and high decreasing (169 [6.0%]). After adjustment for covariates (sex, age, race, study center, education, smoking status, and alcohol consumption), participants in the moderate decreasing (risk ratio [RR], 0.74; 95% CI, 0.54-0.85) and the high decreasing (RR, 0.59; 95% CI, 0.44-0.80) VPA trajectories had a lower risk of NAFLD in middle age, relative to participants in the low stable VPA trajectory. Adjustments for baseline body mass index and waist circumference attenuated these estimates, but the results remained statistically significant. The adjusted RRs across the MPA trajectories were close to null and not statistically significant., Conclusions and Relevance: This cohort study of Black and White participants found a reduced risk of NAFLD in middle age for individuals with higher levels of VPA throughout young to middle adulthood compared with those with lower VPA levels. These results suggest the need for promoting sustainable and equitable prevention programs focused on VPA over the life course to aid in lowering NAFLD risk.

Background: The prevalence of non-alcoholic fatty liver disease (NAFLD) in U.S. adults is over 30%, yet the role of lifestyle factors in the etiology of NAFLD remains understudied. We examined the associations of physical activity, by intensity and type, and television viewing with prevalent NAFLD., Methods: Cross-sectional analysis of a population-based sample of 2726 Black (49%) and White (51%) adults (Mean (SD) age, 50 (3.6) years; 57.3% female) from the CARDIA study. Exposures were aerobic activity by intensity (moderate, vigorous; hours/week); activity type (aerobic, muscle-strengthening; hours/week); and television viewing (hours/week), examined concurrently in all models and assessed by validated questionnaires. Our outcome was NAFLD (liver attenuation < 51 Hounsfield Units), measured by non-contrast computed tomography, after exclusions for other causes of liver fat. Covariates were sex, age, race, study center, education, diet quality, smoking status, alcohol consumption, and body mass index or waist circumference., Results: 648 participants had NAFLD. In the fully adjusted modified Poisson regression model, the risk ratios per interquartile range of each exposure were moderate-intensity aerobic activity, 1.10 (95% CI, 0.97-1.26); vigorous-intensity aerobic activity, 0.72 (0.63-0.82); muscle-strengthening activity, 0.89 (0.80-1.01); and television viewing, 1.20 (1.10-1.32). Relative to less active participants with higher levels of television viewing, those who participated in ≥2 h/week of both vigorous-intensity aerobic and muscle-strengthening activity and <7 h/week of television viewing had 65% lower risk of NAFLD (risk ratio = 0.35, 95% CI = 0.23-0.51)., Conclusion: Adults who follow public health recommendations for vigorous-aerobic and muscle-strengthening activity, as well as minimize television viewing, are considerably less likely to have NAFLD than those who do not follow the recommendations and who have relatively high levels of television viewing.

Apart from physical activity volume, frequent breaks from sedentary bouts and active bouts may differentially reduce fall and fracture risk. We assessed the longitudinal relationship between frequency of breaks from time spent sedentary and frequency of active bouts with recurrent falls and fractures. The sample included 2918 men aged 79.0 ± 5.1 years with free-living activity (SenseWear Armband) at the Osteoporotic Fractures in Men Study (MrOS) year 7 (2007-2009) visit. Men were divided into quartiles by the number of breaks from sedentary bouts (sedentary bout: 5+ minutes sedentary; <1.5 metabolic equivalents of task [METS]) and separately by active bout frequency (active bout: 5+ minutes of activity; ≥1.5 METS). Recurrent falls (2+ falls/year) and fractures were ascertained by self-report; fractures were radiographically confirmed. Generalized estimating equations estimated the recurrent fall odds, with restricted cubic splines applied to assess nonlinear relationships. Cox proportional hazards models estimated fracture risk. Over 4 years of follow-up after year 7, 1025 (35.1%) men were fallers. Over 8.40 ± 4.10 years of follow-up, 640 (21.9%) men experienced a fracture. There was a significant nonlinear U-shaped relationship between number of breaks from sedentary bouts and recurrent falls ( p  < 0.001); compared with men with few breaks from sedentary bouts (1.4-<13.6), the odds of recurrent falls were lower with a moderate number (13.6-<17.0, odds ratio [OR] = 0.82, 95% confidence interval [CI] 0.66, 1.01; 17.0-<20.4, OR = 0.79, 95% CI 0.64, 0.99), but not with the highest number of breaks from sedentary bouts (20.4-34.6, OR = 1.01, 95% CI 0.81, 1.27). Results remained borderline significant after adjusting for total sedentary time. Men with the highest compared with the lowest number of breaks from sedentary bouts had a lower fracture risk, but the association was attenuated after adjustment for total sedentary time. No associations were observed for active bout frequency. In conclusion, breaking up extended periods of sedentary time reduces fall risk regardless of total sedentary time. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research., (© 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.)

Evidence suggests that individuals diagnosed with Parkinson's Disease (PD) spend less time in moderate-to-vigorous intensity physical activity (MVPA) compared to those without PD. However, prior studies primarily included men and did not consider movement across the entire intensity spectrum. To address these gaps, the association of PD status with total volume physical activity and time spent in sedentary, low light-intensity physical activity (LLPA), high light-intensity physical activity (HLPA), and MVPA among older women was examined. This is a cross-sectional analysis of 17,466 ambulatory women enrolled in the Women's Health Study (WHS) with a median (IQR) age of 70 (67-75) years who were asked to wear an accelerometer for 7 days from 2011 to 2015 for the ancillary study. Reported PD status was assessed via annual mail-in questionnaires prior to device wear. Compared to those without PD (n = 16,661), PD (n = 80) was associated with 98,400 fewer vector magnitude (VM) counts per day and with spending an average of 23.2 more minutes per day sedentary and 10.5 more minutes per day in LLPA. Further, PD was associated with spending 6.4 and 27.3 fewer minutes per day in HLPA and MVPA, respectively, compared to women without PD. PD in women is associated with more daily sedentary time and less time spent in health-enhancing physical activity. Prevention strategies to promote physical activity should be emphasized to enhance health and limit progression of disability in women living with PD., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Background: Hearing loss is highly prevalent in older ages and has several health consequences. Some cardiovascular risk factors are associated with worse hearing at older ages. Still, the role of midlife leisure-time physical activity (PA) as a risk factor for hearing loss is yet to be investigated., Methods: Among 3 198 participants of the Atherosclerosis Risk in Communities study, we investigated the associations of midlife and change from mid- to late-life PA (assessed via modified Baecke questionnaire) with hearing loss (audiometric battery [worse-ear pure-tone average, and speech-in-noise test]) at older ages. We used regression analyses, adjusted for demographics, medical conditions, and noise exposure, to estimate differences in hearing between those who met and did not meet PA recommendations at midlife and at late life., Results: A total of 1 386 (43.3%) participants met PA recommendations at midlife. These participants, compared to those who did not meet recommendations, had lower (better) pure-tone average by 1.51 (0.46, 2.55) decibels, identified 0.37 (0.01, 0.74) more words (better score) in the speech-in-noise test, and had a lower relative risk of having hearing loss at older ages (eg, relative risk ratio for severe hearing loss vs normal hearing = 0.70 [0.52, 0.95]). Similarly, those who persistently met PA recommendations from mid- to late life had, compared with those who did not, a better hearing at older ages., Conclusions: Meeting PA public health recommendations in midlife and mid- to late life was associated with better hearing at older ages and reduced risk of hearing loss. Promoting adequate levels of PA may be an essential component of hearing care., (© The Author(s) 2022. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objectives: To determine whether physical function (PF) before menopause is related to cardiovascular disease (CVD) risk., Methods: Participants were N = 2950 pre-/early peri-menopausal women (median age 46, (25th-75th percentile: 43-48 years). Physical function was assessed at baseline using the Physical Function subscale of the SF-36 and scores were trichotomized (no, some, or substantial limitations). Clinical CVD events were ascertained at annual/biennial clinical assessments through the 15th follow-up visit. Risk of CVD was determined with Cox proportional hazards models. Results: Women were followed for a median of 19.1 years, during which 220 women had a CVD event. In fully adjusted models, women with substantial limitations at baseline had higher CVD risk compared to women with no limitations (hazards ratio [HR] = 1.55, 95% confidence interval [CI]: 1.12-2.33). Discussion: Substantial PF limitations in pre- and early peri-menopausal women are associated with higher risk of clinical CVD events, consistent with literature in older adults.

Objective: We evaluated the prospective association of midlife leisure-time physical activity (LTPA) and sedentary behavior (SB), and their temporal patterns, with MRI-measured carotid atherosclerotic morphology., Methods: Participants enrolled in the Carotid MRI substudy (2004-2006) of the Atherosclerosis Risk in Communities (ARIC) Study and with self-reported assessments of LTPA and SB at visits 1 (1987-1989) and 3 (1993-1995) were included in this study. LTPA was ascertained using the ARIC/Baecke physical activity questionnaire and categorized according to the American Heart Association's metric of poor, intermediate, or ideal physical activity. SB, measured as TV viewing frequency, was categorized as high, medium, and low. We used multivariable adjusted linear and logistic regression models to examine the associations between midlife (visit 3 only) and persistent (visit 1 to 3) LTPA and TV viewing with carotid artery plaque burden and components., Results: Among the 1,582 (mean age: 59 years, 43% male, 18% Black) participants, 45.7%, 21.7%, and 32.6% reported ideal, intermediate, or poor LTPA, respectively. High TV viewing was reported in 33.8% of participants, with 46.4% and 19.8% reporting medium or low TV viewing, respectively. Compared to poor LTPA, ideal LTPA in midlife was not associated with total wall volume ( ß =0.01, 95% CI: -0.01, 0.03), maximum carotid wall thickness ( ß =0.06, 95% CI: -0.08, 0.21), normalized wall index ( ß =-0.01, 95% CI: -0.03, 0.01), or maximum stenosis ( ß =-0.11, 95% CI: -1.98, 1.76). Low or middle, compared to high, TV viewing was also not associated with carotid artery measures of plaque burden. Compared to poor LTPA or high TV viewing, ideal LTPA (odds ratio (OR): 0.82, 95% CI: 0.55, 1.23) and low TV viewing (OR=0.90, 95% CI: 0.56, 1.44) was not associated with odds of lipid core presence, respectively., Conclusion: Overall, this study does not provide strong evidence for an association between LTPA and SB with carotid plaque measures., Competing Interests: The authors have no conflicts of interest., (© 2023 The Authors. Published by Elsevier B.V.)

Background: Time awake with advancing age is increasingly spent sedentary and has several negative health consequences. We examined associations between the frequency of daily sedentary and active bouts with all-cause mortality., Methods: Data are from 2816 men in the Osteoporotic Fractures in Men (MrOS) Study (mean age ± SD: 79.1 ± 5.2 years) with free-living activity monitor (SenseWear® Pro3 Armband) data (5.1 ± 0.3 days worn >90%) at the Year 7 visit (2007-2009). Sedentary bout frequency was defined as the number of sedentary bouts per day lasting 5+ min to activity of any intensity. Active bout frequency was defined as the number of active bouts per day lasting 5+ min to sedentary behavior. Sleep time was excluded from the analysis. Deaths were centrally adjudicated using death certificates. Cox proportional hazard models were used to separately examine associations between quartiles of sedentary (Q1 referent, <13.6 bouts/day) or active (Q1 referent, <5 bouts/day) bout frequency with mortality., Results: After 9.3 ± 3.8 years of follow-up, 1487 (52.8%) men died. Men averaged 16.8 ± 5.1 and 8.2 ± 4.2 sedentary and active bouts/day, respectively. After full covariate adjustment, each quartile reflecting more frequent sedentary bouts (Q4 vs. Q1 HR: 0.69, 95%CI: 0.58, 0.81, p-trend <0.001) was associated with lower mortality risk. Likewise, each quartile reflecting more frequent active bouts (Q4 vs. Q1 HR: 0.58, 95%CI: 0.49, 0.70, p-trend <0.001) was associated with lower mortality risk. Results for the sedentary bouts model remained significant after adjusting for total minutes per day in sedentary behavior (Q4 vs. Q1 HR: 0.63, 95%CI: 0.61, 0.86, p-trend = 0.001). The association between active bout frequency with mortality was attenuated after adjusting for total minutes per day active., Conclusions: Regardless of total time spent sedentary, reducing duration of sedentary bouts with more frequent and shorter bouts may be a simple and feasible method to delay mortality risk among community-dwelling older men., (© 2023 The American Geriatrics Society.)

Background: Whether greater leisure time physical activity (LTPA) is associated with less bone mineral density (BMD) loss during the menopause transition (MT) remains an open question. We hypothesized that: 1) larger increases in LTPA from pre-/early perimenopause (period 1) to late perimenopause/postmenopause (period 2) would be associated with a slower period 2 BMD loss rate; and 2) greater entire-study LTPA levels would be associated with better final absolute BMD (g/cm 2 )., Methods: Data were from of the Study of Women's Health Across the Nation (1996-2017). Exclusions were: bone beneficial medications, inability to identify start of the MT, and extreme BMD change rates. LTPA measures were a validated ordinal scale and number of metabolic equivalents per hour per week (MET hr wk -1 ) from sport/exercise. Multiply adjusted, linear regression models estimated: 1) BMD decline rate (annualized %) as a function of LTPA change; and 2) final BMD as a function of entire-study LTPA., Findings: Median [p25, p75] MET hr wk -1 were 4.2 [0.9, 10.1] and 4.9 [1.4, 11.2] in periods 1 and 2, respectively; walking was the commonest activity. In adjusted models (N = 875), greater increases in LTPA ordinal score and MET hr wk -1 were statistically significantly associated with a slower decline in femoral neck (FN) BMD. Larger entire-study averages of each LTPA measure were statistically significantly related to better final FN and lumbar spine BMD levels., Interpretation: Findings suggest that LTPA, at modest levels, mitigate MT-related BMD decline and even small increases in intensity, duration or frequency of common activities may lessen bone loss at the population level., Funding: US-NIH., Competing Interests: All authors declare that they have no financial relationships with any organisation that might have an interest in the submitted work and have no other relationships or activities that could appear to have influenced the submitted work., (© 2023 The Authors.)

Importance: The Physical Activity Guidelines Advisory Committee Scientific Report identified important research gaps to inform future guidance for adolescents, including limited evidence on the importance of sedentary behaviors (screen time) and their interactions with physical activity for adolescent health outcomes, including overweight and obesity., Objective: To identify the independent associations of physical activity and screen time categories, and the interactions between physical activity and screen time categories, with body mass index (BMI) and overweight and obesity in adolescents., Design, Setting, and Participants: This cross-sectional study used data from the Adolescent Brain Cognitive Development (ABCD) Study collected from September 10, 2018, to September 29, 2020. Data were analyzed from July 8 to December 20, 2022. A total of 5797 adolescents aged 10 to 14 years from 21 racially and ethnically diverse study sites across the US were included in the analysis., Exposures: Categories of total step count per day (with 1000 to 6000 steps per day indicating low, >6000 to 12 000 steps per day indicating medium, and >12 000 steps per day indicating high), as measured by a wearable digital device (Fitbit), and categories of self-reported screen time hours per day (with 0 to 4 hours per day indicating low, >4 to 8 hours per day indicating medium, and >8 hours per day indicating high)., Main Outcomes and Measures: Participant BMI was calculated as weight in kilograms divided by height in meters squared and converted into sex- and age-specific percentiles in accordance with the Centers for Disease Control and Prevention growth curves and definitions. Individuals were classified as having overweight or obesity if their BMI was in the 85th percentile or higher for sex and age., Results: Among 5797 adolescents included in the analytic sample, 50.4% were male, 61.0% were White, 35.0% had overweight or obesity, and the mean (SD) age was 12.0 (0.6) years. Mean (SD) reported screen time use was 6.5 (5.4) hours per day, and mean (SD) overall step count was 9246.6 (3111.3) steps per day. In models including both screen time and step count, medium (risk ratio [RR], 1.24; 95% CI, 1.12-1.37) and high (RR, 1.29; 95% CI, 1.16-1.44) screen time categories were associated with higher overweight or obesity risk compared with the low screen time category. Medium (RR, 1.19; 95% CI, 1.06-1.35) and low (RR, 1.30; 95% CI, 1.11-1.51) step count categories were associated with higher overweight or obesity risk compared with the high step count category. Evidence of effect modification between screen time and step count was observed for BMI percentile. For instance, among adolescents with low screen use, medium step count was associated with a 1.55 higher BMI percentile, and low step count was associated with a 7.48 higher BMI percentile. However, among those with high screen use, step count categories did not significantly change the association with higher BMI percentile (low step count: 8.79 higher BMI percentile; medium step count: 8.76 higher BMI percentile; high step count: 8.26 higher BMI percentile)., Conclusions and Relevance: In this cross-sectional study, a combination of low screen time and high step count was associated with lower BMI percentile in adolescents. These results suggest that high step count may not offset higher overweight or obesity risk for adolescents with high screen time, and low screen time may not offset higher overweight or obesity risk for adolescents with low step count. These findings addressed several research gaps identified by the Physical Activity Guidelines Advisory Committee Scientific Report and may be used to inform future screen time and physical activity guidance for adolescents.

Background: Daily 24-h sleep-wake cycles have important implications for health, however researcher preferences in choice and location of wearable devices for behavior measurement can make 24-h cycles difficult to estimate. Further, missing data due to device malfunction, improper initialization, and/or the participant forgetting to wear one or both devices can complicate construction of daily behavioral compositions. The Method for Activity Sleep Harmonization (MASH) is a process that harmonizes data from two different devices using data from women who concurrently wore hip (waking) and wrist (sleep) devices for ≥ 4 days., Methods: MASH was developed using data from 1285 older community-dwelling women (ages: 60-72 years) who concurrently wore a hip-worn ActiGraph GT3X + accelerometer (waking activity) and a wrist-worn Actiwatch 2 device (sleep) for ≥ 4 days (N = 10,123 days) at the same time. MASH is a two-tiered process using (1) scored sleep data (from Actiwatch) or (2) one-dimensional convolutional neural networks (1D CNN) to create predicted wake intervals, reconcile sleep and activity data disagreement, and create day-level night-day-night pairings. MASH chooses between two different 1D CNN models based on data availability (ActiGraph + Actiwatch or ActiGraph-only). MASH was evaluated using Receiver Operating Characteristic (ROC) and Precision-Recall curves and sleep-wake intervals are compared before (pre-harmonization) and after MASH application., Results: MASH 1D CNNs had excellent performance (ActiGraph + Actiwatch ROC-AUC = 0.991 and ActiGraph-only ROC-AUC = 0.983). After exclusions (partial wear [n = 1285], missing sleep data proceeding activity data [n = 269], and < 60 min sleep [n = 9]), 8560 days were used to show the utility of MASH. Of the 8560 days, 46.0% had ≥ 1-min disagreement between the devices or used the 1D CNN for sleep estimates. The MASH waking intervals were corrected (median minutes [IQR]: -27.0 [-115.0, 8.0]) relative to their pre-harmonization estimates. Most correction (-18.0 [-93.0, 2.0] minutes) was due to reducing sedentary behavior. The other waking behaviors were reduced a median (IQR) of -1.0 (-4.0, 1.0) minutes., Conclusions: Implementing MASH to harmonize concurrently worn hip and wrist devices can minimizes data loss and correct for disagreement between devices, ultimately improving accuracy of 24-h compositions necessary for time-use epidemiology.

Background: Cross-sectional studies have demonstrated associations between screen time and disruptive behavior disorders (conduct disorder and oppositional defiant disorder); however, prospective associations remain unknown. This study's objective was to determine the prospective associations of contemporary screen time modalities with conduct and oppositional defiant disorder in a national cohort of 9-11-year-old children., Methods: We analyzed data from the Adolescent Brain Cognitive Development (ABCD) Study (N = 11,875). Modified Poisson regression analyses were conducted to estimate the associations between baseline child-reported screen time (total and by modality) and parent-reported conduct or oppositional defiant disorder based on the Kiddie Schedule for Affective Disorders and Schizophrenia (KSADS-5) at 1-year follow-up, adjusting for potential confounders., Results: Participants reported an average of 4 hr of total screen time per day at baseline. Each hour of total screen time per day was prospectively associated with a 7% higher prevalence of conduct disorder (95% CI 1.03-1.11) and a 5% higher prevalence of oppositional defiant disorder (95% CI 1.03-1.08) at 1-year follow-up. Each hour of social media per day was associated with a 62% higher prevalence of conduct disorder (95% CI 1.39-1.87). Each hour of video chat (prevalence ratio [PR] 1.21, 95% CI 1.06-1.37), texting (PR 1.19, 95% CI 1.07-1.33), television/movies (PR 1.17, 95% CI 1.10-1.25), and video games (PR 1.14, 95% CI 1.07-1.21) per day was associated with a higher prevalence of the oppositional defiant disorder. When examining thresholds, exposure to >4 hr of total screen time per day was associated with a higher prevalence of conduct disorder (69%) and oppositional defiant disorder (46%)., Conclusions: Higher screen time was prospectively associated with a higher prevalence of new-onset disruptive behavior disorders. The strongest association was between social media and conduct disorder, indicating that future research and interventions may focus on social media platforms to prevent conduct disorder., (© 2022 Association for Child and Adolescent Mental Health.)

Background: Understanding how sleep, sedentary behavior (SED), and physical activity (PA) (24-h movement profile) changes across pregnancy in individuals with prepregnancy overweight or obesity and how parity (previous births) impacts these changes can help inform interventions., Methods: In 155 participants, movement was measured using wrist-worn accelerometers, and sleep was self-reported in early (8-15 wk) and late (29-38 wk) pregnancy. The 24-hour movement profiles were analyzed using compositional analyses., Results: Nulliparous participants (no previous births) spent 33.95%, 38.14%, 25.32%, and 2.58% of the 24-hour day in early pregnancy in sleep, SED, light-intensity PA, and moderate/vigorous-intensity PA, respectively. Multiparous participants (≥1 previous birth) spent 2.50 percentage points less in SED (mean log-ratio difference = -0.068; 95% confidence interval [CI], -0.129 to -0.009) and 2.73 percentage points more in light-intensity PA (mean log-ratio difference = 0.102; 95% CI, 0.035 to 0.180). From early to late pregnancy, participants decreased the proportion of the 24-hour day spent asleep by 1.67 percentage points (mean log-ratio difference = -0.050; 95% CI, -0.092 to -0.011) and increased light-intensity PA by 1.56 percentage points (mean log-ratio difference = 0.057; 95% CI, 0.003 to 0.108), with no change in other behaviors., Conclusions: Nulliparous and multiparous individuals with prepregnancy overweight or obesity both had high levels of SED, with no change across pregnancy, and may require interventions to reduce  SED.

Physical activity (PA) plays an important role in cognitive health. However, the underlying mechanisms are not fully understood. Cardiac autonomic balance is influenced by PA and implicated in dementia pathogenesis. We examined whether autonomic balance mediates the association between PA and cognitive function. The sample included 1939 participants from the Coronary Artery Risk Development in Young Adults study who completed cognitive testing after 30-year follow-up (baseline: mean age 25.2 ± 3.5y; 58% women; 43% Black). Moderate to vigorous intensity PA (MVPA) was obtained in 7 consecutive examinations over 20 years (Year 0-Year 20). Cardiac autonomic balance was assessed at Year 20 via resting heart rate (RHR), standard deviation normal to normal (SDNN) and root mean square of successive differences (RMSSD). We used group-based trajectory modeling to identify homogenous MVPA trajectory groups, and formal mediation analysis to test whether autonomic function indices mediate the association between MVPA trajectories and cognition. We identified three distinct PA trajectory patterns: (1) Below MVPA guidelines (n = 1122; 57.9%); (2) Meeting MVPA guidelines (n = 652; 33.6%); and (3) Exceeding MVPA guidelines (n = 165; 8.5%). Meeting and exceeding MVPA guidelines were related to better autonomic balance overall, and to improved semantic fluency performance. Statistically, the association between higher MVPA level and verbal ability was mediated by SDNN and RMSSD, but not by RHR. In our sample of young and middle-aged adults, higher MVPA levels over time were associated with better cardiac autonomic function, which explained some of the associations between PA trajectories and better cognition., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Purpose: This study examined whether employment status during mid-life and older adulthood is associated with physical function impairment., Methods: Participants were 2700 women in the multiracial/multiethnic Study of Women's Health Across the Nation. Time-varying, lagged, and cumulative exposure analyses modeled associations between self-reported employment status and the likelihood of severe physical function impairment across 19 years of follow-up., Results: Independent of demographic variables, women who were not working (OR = 1.58, 95% CI = 1.22, 2.04) or employed part-time (OR = 1.29, 95% CI = 1.04, 1.61) were more likely to report severe physical function impairments than women employed full-time. This same pattern was seen in lagged analyses predicting risk of physical function impairment from employment status at the prior assessment (not working vs. full-time: OR = 1.53, 95% CI = 1.08, 2.18; part-time vs. full-time: OR = 1.53, 95% CI = 1.17, 2.00). The likelihood of severe physical function impairment increased by 20% for every additional 10% of follow-up spent not working (OR = 1.02, 95% CI: 1.01, 1.03). Associations were robust to adjustment for health-related variables, body mass index, and physical activity., Conclusions: Women with lower levels of employment from mid-life to older adulthood were more likely to experience severe impairment in physical function. However, the underlying mechanisms, and the timescales over which associations unfold, require further study., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Although physical activity is generally protective of cardiovascular disease (CVD), less is known about how young adult physical activity relates to premature CVD events. The objective of this study was to determine the association between level and change in physical activity from young adulthood to middle age and incidence of premature CVD events before age 60., Methods: We analyzed data collected across four urban sites from nine visits over 30 years of follow-up (1985-2016) from the Coronary Artery Risk Development in Young Adults (CARDIA) study, a prospective community-based cohort study of 5115 Black and White women and men aged 18-30 years at baseline (1985-1986). Linear mixed models were used to develop individualized moderate-to-vigorous intensity self-reported physical activity trajectories per participant. Fatal and nonfatal coronary heart disease (CHD), heart failure, and stroke outcomes were analyzed separately and as a combined CVD event outcome., Results: Overall, physical activity declined in young adults as they progressed through middle age. Lower physical activity scores (per 100 exercise units) in 18 year-olds were associated with higher odds of premature CHD (AOR 1.14, 95% CI 1.02-1.28), heart failure (AOR 1.21, 95% CI 1.05-1.38), stroke (AOR 1.20, 95% CI 1.04-1.39), and any CVD (AOR 1.15, 95% CI 1.06-1.24) events. Each additional annual 1-unit reduction in the physical activity score was associated with a higher annual odds of incident heart failure (1.07, 95% CI 1.02-1.13), stroke (1.06, 95% CI 1.00-1.13), and CVD (1.04, 95% CI 1.01-1.07) events. Meeting the minimum (AOR 0.74, 95% CI 0.0.57-0.96) and twice the minimum (AOR 0.55, 95% CI 0.34-0.91) Department of Health and Human Services physical activity guidelines through follow up was protective of premature CVD events., Conclusions: Given recent trends in declining physical activity with age and associated premature CVD events, the transition from young adult to midlife is an important time period to promote physical activity., (© 2022. The Author(s).)

Background Cardiorespiratory fitness is a powerful predictor of health outcomes that is currently underused in primary prevention, especially in young adults. We sought to develop a blood-based biomarker of cardiorespiratory fitness that is easily translatable across populations. Methods and Results Maximal effort cardiopulmonary exercise testing for quantification of cardiorespiratory fitness (by peak oxygen uptake) and profiling of >200 metabolites at rest were performed in the FHS (Framingham Heart Study; 2016-2019). A metabolomic fitness score was derived/validated in the FHS and was associated with long-term outcomes in the younger CARDIA (Coronary Artery Risk Development in Young Adults) study. In the FHS (derivation, N=451; validation, N=914; age 54±8 years, 53% women, body mass index 27.7±5.3 kg/m 2 ), we used LASSO (least absolute shrinkage and selection operator) regression to develop a multimetabolite score to predict peak oxygen uptake (correlation with peak oxygen uptake r =0.77 in derivation, 0.61 in validation; both P <0.0001). In a linear model including clinical risk factors, a ≈1-SD higher metabolomic fitness score had equivalent magnitude of association with peak oxygen uptake as a 9.2-year age increment. In the CARDIA study (N=2300, median follow-up 26.9 years, age 32±4 years, 44% women, 44% Black individuals), a 1-SD higher metabolomic fitness score was associated with a 44% lower risk for mortality (hazard ratio [HR], 0.56 [95% CI, 0.47-0.68]; P <0.0001) and 32% lower risk for cardiovascular disease (HR, 0.68 [95% CI, 0.55-0.84]; P =0.0003) in models adjusted for age, sex, and race, which remained robust with adjustment for clinical risk factors. Conclusions A blood-based biomarker of cardiorespiratory fitness largely independent of traditional risk factors is associated with long-term risk of cardiovascular disease and mortality in young adults.

Background: Longitudinal association of television (TV) viewing and moderate- to vigorous-intensity physical activity (MVPA) with pericardial adipose tissue (PAT) is unclear., Methods: We studied Coronary Artery Risk Development in Young Adults Study participants transitioning from early to middle age at Coronary Artery Risk Development in Young Adults (CARDIA) exam years 15 (2000-2001; N = 1975, mean age = 40.4, 55.4% women, 45.3% Black) and 25 (2010-2011). TV viewing (in hours per day) and MVPA (in exercise units) were measured using a self-report questionnaire. PAT volume (in milliliters) was measured using computed tomography. Multivariable linear regression was used to examine the associations of tertiles of 10-year change (years 25-15) in TV viewing and MVPA with a concurrent change in PAT with adjustments for covariates., Results: Participants in the highest tertile of 10-year increase in TV viewing had a greater increase in PAT (β = 2.96 mL, P < .01). Participants in both middle (β = -3.93 mL, P < .01) and highest (β = -6.22 mL, P < .01) tertiles of 10-year changes in MVPA had smaller mean increases in PAT over 10 years when compared with the lowest tertile in fully adjusted models., Conclusions: Reducing or maintaining early-midlife levels of TV viewing and increasing MVPA may be associated with less PAT accumulation with age.

The Collaborative Cohort of Cohorts for COVID-19 Research (C4R) is a national prospective study of adults comprising 14 established US prospective cohort studies. Starting as early as 1971, investigators in the C4R cohort studies have collected data on clinical and subclinical diseases and their risk factors, including behavior, cognition, biomarkers, and social determinants of health. C4R links this pre-coronavirus disease 2019 (COVID-19) phenotyping to information on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and acute and postacute COVID-related illness. C4R is largely population-based, has an age range of 18-108 years, and reflects the racial, ethnic, socioeconomic, and geographic diversity of the United States. C4R ascertains SARS-CoV-2 infection and COVID-19 illness using standardized questionnaires, ascertainment of COVID-related hospitalizations and deaths, and a SARS-CoV-2 serosurvey conducted via dried blood spots. Master protocols leverage existing robust retention rates for telephone and in-person examinations and high-quality event surveillance. Extensive prepandemic data minimize referral, survival, and recall bias. Data are harmonized with research-quality phenotyping unmatched by clinical and survey-based studies; these data will be pooled and shared widely to expedite collaboration and scientific findings. This resource will allow evaluation of risk and resilience factors for COVID-19 severity and outcomes, including postacute sequelae, and assessment of the social and behavioral impact of the pandemic on long-term health trajectories., (Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health 2022. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

Purpose: We examined associations of sedentary behavior (SB), light-intensity physical activity (LPA), and moderate-to-vigorous intensity physical activity (MVPA) with pericardial adipose tissue (PAT)., Methods: Adults from the Multi-Ethnic Study of Atherosclerosis were included from exam years 1 (2000-2002; N = 6057; mean age, 62.2 yr; 52.9% female, 38.0% White; 12.8% Chinese American, 26.7% African American, 22.5% Hispanic American), 2 (2002-2004), and 3 (2004-2005). Weekly volume of SB, LPA, and MVPA (in MET-hours per week) was reported using a questionnaire. PAT volume (in cubic centimeters) was quantified using computed tomography, analysis of covariance, and repeated-measures linear mixed models with adjustment for covariates (sociodemographics, cardiovascular disease risk factors, inflammation, waist circumference) tested cross-sectional and longitudinal associations, respectively., Results: In cross-sectional analysis, the highest tertile of SB (β = 2.71; 95% confidence interval (CI), 0.69 to 4.73; P < 0.01) and the middle tertile of MVPA (β = -1.97; 95% CI, -3.92 to -0.02; P < 0.05) were associated with PAT, whereas no association was observed for LPA in fully adjusted models. In longitudinal models, SB, LPA, and MVPA were not associated with PAT in the full study sample; however, LPA was inversely associated with PAT among Whites in stratified analysis (β = -0.54; 95% CI, -0.95 to -0.13; P < 0.05)., Conclusions: Lower SB and higher LPA (among Whites only) and MVPA may be associated with lower PAT, but additional longitudinal research is needed., (Copyright © 2022 by the American College of Sports Medicine.)

This study cross-sectionally examines the relations of sitting and physical activity (PA) with cognitive impairment in community-dwelling adults aged 55-87 years (n = 3,780). Multivariable logistic regression assessed independent and joint relations of sitting and PA with Montreal Cognitive Assessment scores adjusting for covariates. Sitting ≥75% of the time and not meeting PA guidelines were related to 60% (95% confidence interval [CI] [1.19, 2.17]) and 27% (95% CI [1.06, 1.53]) higher odds for cognitive impairment, respectively. Stratification by age showed that sitting ≥75% of the time was associated with higher cognitive impairment odds in midlife (odds ratio [OR] = 1.86; 95% CI [1.31, 2.65]), but not older adults (OR = 1.06; 95% CI [0.57, 1.95]). Joint association analysis revealed that, overall, the highest odds for cognitive impairment were in those sitting ≥75% of the time while meeting or not meeting PA guidelines (OR = 1.69, 95% CI [1.13, 2.53]; and OR = 1.66, 95% CI [1.19, 2.32], respectively). In conclusion, prolonged sitting and insufficient PA are independent risk markers for cognitive impairment.

Pericardial adipose tissue (PAT), an ectopic adipose depot surrounding the coronary arteries, is a pathogenic risk marker for cardiometabolic disease; however, the association between cardiorespiratory fitness (CRF) and PAT is unclear. Young adults (n = 2,614, mean age 25.1 years, 55.8% women, and 43.8% Black at baseline [1985 to 1986]) from the Coronary Artery Risk Development in Young Adults study were included. Maximal CRF was estimated at baseline, examination year 7 (1992 to 1993) and year 20 (2005 to 2006), using a symptom-limited maximal treadmill exercise test (duration in minutes) among those achieving ≥85% of age-predicted maximal heart rate. PAT volume (ml) was quantified at examination year 15 (2000 to 2001) and year 25 (2010 to 2011) using computed tomography. Multivariable linear and linear mixed regressions with covariates (sociodemographics, cardiovascular disease risk factors, inflammation, waist circumference) from baseline, year 7, and/or year 20 were used. Separate multivariable regression models revealed inverse associations of CRF at baseline, year 7, or year 20 with PAT at year 25 in fully adjusted models (all p <0.001). The linear mixed model showed that a 1-minute increase in treadmill exercise test duration over 20 years was associated with 1.49 ml lower subsequent PAT volume (p <0.001). In conclusion, findings suggest that higher CRF is inversely associated with subsequent PAT volume. Strategies to optimize CRF may be preventive against excessive PAT accumulation with age., (Copyright © 2022 Elsevier Inc. All rights reserved.)