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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.

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 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.

Related Perspective from Physical Activity and Survival in Postmenopausal Women with Breast Cancer: Results from the Women's Health Initiative

Log hazard smoothing spline plot.

To investigate whether the impact of postdiagnosis exercise on breast cancer outcomes in women diagnosed with early-stage breast cancer differs on the basis of tumor clinicopathologic and molecular features. Using a prospective design, 6,211 patients with early-stage breast cancer from two large population-based cohort studies were studied. Age-adjusted and multivariable Cox regression models were performed to determine the relationship between exercise exposure (total MET-hours/week) and recurrence and breast cancer–related death for: (i) all patients (“unselected” cohort), and on the basis of (ii) classic clinicopathologic features, (iii) clinical subtypes, (iv) PAM50-based molecular intrinsic subtypes, and (v) individual PAM50 target genes. After a median follow-up of 7.2 years, in the unselected cohort (n = 6,211) increasing exercise exposure was not associated with a reduction in the risk of recurrence (adjusted Ptrend = 0.60) or breast cancer–related death (adjusted Ptrend = 0.39). On the basis of clinicopathologic features, an exercise-associated reduction in breast cancer–related death was apparent for tumors +/PR+/HER2−/low-grade clinical subtype was preferentially responsive to exercise (recurrence: adjusted HR, 0.63; 95% CI, 0.45–0.88; breast cancer–related death: adjusted HR, 0.57; 95% CI, 0.37–0.86). The impact of exercise on cancer outcomes appears to differ as a function of pathologic and molecular features in early-stage breast cancer. Cancer Res; 76(18); 5415–22. ©2016 AACR.

Introduction: Strong evidence suggests physical activity may prevent cognitive decline. Less research has explored potential associations of physical activity with brain structure. This is an important research gap given that age related alterations in brain structure are thought to occur prior to signs of cognitive decline. Objective: To determine if accelerometer measured sedentary time (SED), light-intensity physical activity (LPA), and moderate-to-vigorous intensity physical activity (MVPA) at ages 38-50 years are prospectively associated with brain structure. Methods: We studied 562 Black and White men and women enrolled in CARDIA who participated in the 2005-06 exam (baseline) and exams 5 (2010-11) and/or 10 years later (2015-16). SED, LPA, and MVPA were measured by the ActiGraph 7164 accelerometer at baseline. Magnetic resonance imaging (MRI) was used to quantify whole brain, white matter, gray matter, and abnormal tissue volume of white matter at the 5- and/or 10-year follow-up. Compositional isotemporal substitution analysis examined associations of SED, LPA, and MVPA at baseline with repeated measures (unstructured covariance) of MRI measures at follow-up after accounting for intracranial volume and adjusting for confounders ( Table ). Results: Consistent with our hypothesis, substituting 30 minutes of SED to LPA was associated with 0.044% greater total white matter volume (95% CI: 0.001, 0.086). The effect size was larger when substituting SED to MVPA, but this association was not statistically significant. There were no associations observed between accelerometer measures and total brain, total gray matter, or abnormal white matter tissue volumes. Associations did not differ by sex or age. Conclusions: Statistical substitution of time from SED to higher intensity physical activity (LPA or MVPA) was associated with greater total white matter volume. It is unclear why this association was observed in white matter only. Additional research with longer follow-up is needed to confirm these findings.

Introduction: Leisure-time physical activity (LTPA) is known to promote cardiovascular health, while occupational physical activity (OPA) may have paradoxically negative impacts. One proposed, though untested, explanation for the paradoxical associations may be unfavorable vascular remodeling from OPA-induced chronic cardiovascular strain. Hypothesis: High amounts of OPA over 25 years from young adulthood to midlife is associated with adverse left ventricular (LV) structure and function. Methods: Data are from 1,893 participants (48.9% female, 57.3% White, aged 30.4±3.4 years at baseline [the Year 5 exam]) from the Coronary Artery Risk Development in Young Adults (CARDIA) Study who reported working full time at baseline and two years later. LV structure and function was measured as LV mass, end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), stroke volume (SV), and e/a-wave ratio (EA) via M-mode and 2-dimensional echocardiograms at baseline and 25-years later. OPA was reported at seven exams during the study period as months/year where the participant performed “vigorous job activities such as lifting, carrying, or digging” for ≥5 hours/week. The 25-year OPA patterns were categorized into three trajectories: zero OPA (0 months/year; n=995), medium OPA (~2-3 months/year; n=526), and high OPA (~6-8 months/year; n=372). Linear regression estimated longitudinal associations between the OPA trajectories and the echocardiogram variables at final follow-up after adjusting for baseline values. Case-wise deletion was used for each model where only those with valid outcome data were included (n=623-1,475). Results: EF and EA were significantly lower in high versus zero OPA. No other statistically significant associations were observed. (Figure 1) Conclusions: In this sample, OPA’s paradoxical impact on cardiovascular health was partially supported by null or adverse associations between high OPA and LV structure and function. Confirmation is needed using more precise OPA measures.

Introduction: Coronary artery calcification (CAC) score, physical activity (PA), and cardiorespiratory fitness (CRF) are all associated with cardiovascular disease (CVD) risk. While a U-shaped relationship between PA and CRF with CAC has been reported, CAC presence among highly fit individuals was suggested to be benign. Objective: To determine interactive associations of PA/CRF and CAC with outcomes in a cohort of middle-aged adults and to evaluate the relationship of PA/CRF with CAC incidence. Methods: CARDIA participants with CT-assessed CAC at year 20 (2005-06) were included (n=3141, mean age 45y, 57% female, 45% Black). Moderate to vigorous intensity PA (MVPA) was assessed by self-report and accelerometer. CRF was estimated with a treadmill test. Incident CVD events were adjudicated, and mortality data were obtained through 2019. CAC was reassessed at year 25 (2010-11). Cox models assessed hazard ratios (HRs) for CVD and mortality in groups defined by CAC and MVPA/CRF. Logistic models assessed associations with CAC incidence. Results: At baseline, more favorable CVD risk was found among participants with higher MVPA, higher CRF (> median sex-specific duration), and absence of CAC. During a mean follow-up of 13 years, 166 CVD events and 171 deaths occurred. After multivariable adjustment, compared with no CAC and higher CRF (ref), the HRs (95% CIs) for CVD were 5.04 (2.49-10.20) for CAC and higher CRF, 2.26 (1.24-4.12) for no CAC and lower CRF, and 4.27 (2.24-8.14) for CAC and lower CRF (Figure, left panel). The respective HRs for mortality were 1.12 (0.45-2.77), 1.54 (0.91-2.60), and 3.23 (1.82-5.72) (Figure, right panel). Similar findings were observed with self-reported or accelerometer MVPA replacing CRF. Higher CRF and accelerometer MVPA were dose-responsively associated with a lower probability of developing CAC in a 5-year follow-up (P < .01). Conclusions: PA and CRF were inversely associated with CAC incidence in middle-aged adults. CAC presence eliminated the cardiovascular risk advantage of high PA or high CRF.

PURPOSE: To describe maximal and submaximal cardiorespiratory fitness from early adulthood to midlife and examine differences in maximal fitness at age 20 and changes in fitness over-time by sub-categories of socio-demographic, behavioral, and health-related factors. METHODS: Data include 5,018 Coronary Artery Risk Development in Young Adults participants [mean (SD) age 24.8 (3.7) years, 53.3% female and 51.4% Black participants] who completed at least one maximal graded exercise test at baseline and/or the Year 7 and 20 exams. Maximal and submaximal fitness were estimated by exercise duration and heart rate at the end of stage 2. Multivariable adjusted linear mixed models were used to estimate fitness trajectories using age as the mechanism for time after adjustment for covariates. Fitness trajectories from ages 20 to 50 in 5-year increments were estimated overall and by sub-groups determined by each factor after adjustment for duration within the less favorable category. RESULTS: Mean (95% confidence interval) maximal fitness at age 20 and 50 years was 613 (607, 616) and 357 (350, 362) seconds; submaximal heart rate during this period also reflected age-related fitness declines [126 (125, 127) and 138 (137, 138) beats per minute]. Compared to men, women had lower maximal fitness at age 20 (p

ImportanceOptimizing cardiovascular fitness is a prevention strategy against premature death and cardiovascular disease (CVD) events. Since this evidence has largely been established in older populations, the importance of cardiorespiratory fitness during earlier periods of adulthood remains unclear.ObjectiveTo examine the association of early-adulthood cardiorespiratory fitness and percentage of early-adulthood cardiorespiratory fitness retained during midlife with subsequent risk of all-cause mortality and CVD-related morbidity and mortality overall as well as by sex and race.Design, Setting, and ParticipantsThis retrospective population-based cohort study analyzed data from the Coronary Artery Risk Development in Young Adults (CARDIA) study, an ongoing prospective cohort study conducted at field center clinics in Birmingham, Alabama; Chicago, Illinois; Minneapolis, Minnesota; and Oakland, California. Participants in the CARDIA study were aged 18 to 30 years when they completed the baseline graded exercise test protocol in 1985 to 1986 and have since undergone follow-up examinations biannually and every 2 to 5 years. Data were collected through August 31, 2020, and were analyzed in October 2022.ExposuresCardiorespiratory fitness was estimated from a symptom-limited, maximal graded exercise test protocol conducted at baseline and at year 7 and year 20 follow-up examinations.Main Outcomes and MeasuresAll-cause mortality and combined fatal and nonfatal CVD events were obtained since year 20 of follow-up examinations through August 31, 2020. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) for each primary exposure with each outcome.ResultsA total of 4808 participants (mean [SD] age at baseline, 24.8 [3.7] years; 2670 females [56%]; 2438 Black individuals [51%]) were included in the sample. During 68 751 person-years of follow-up, there were 302 deaths (6.3%) and 274 CVD events (5.7%) since year 20. Every 1-minute increment in cardiorespiratory fitness at baseline was associated with a lower risk of all-cause mortality in females (HR, 0.73; 95% CI, 0.64-0.82) and males (HR, 0.87; 95% CI, 0.80-0.96). Every 5% increment in cardiorespiratory fitness retained through year 20 was associated with a lower risk of all-cause mortality (HR, 0.89; 95% CI, 0.79-0.99), but no evidence of effect modification by race or sex was found. Every 1-minute increment in cardiorespiratory fitness at baseline was associated with a lower risk of fatal or nonfatal CVD (HR, 0.89; 95% CI, 0.82-0.96), and the estimated HR per 5% increment in cardiorespiratory fitness retained throughout midlife was 0.89 (95% CI, 0.78-1.00), with no evidence for interaction by race or sex.Conclusions and RelevanceThis cohort study found that higher early-adulthood cardiorespiratory fitness and greater retention of early-adulthood cardiorespiratory fitness throughout midlife were associated with a lower risk of premature death and CVD events. Additional research is needed to clarify the association of cardiorespiratory fitness timing across the life course with risk of clinical outcomes.