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Background Grip strength has prognostic value for aging-related health outcomes. Whether the associations of grip strength with the risk of dementia and Alzheimer's disease (AD) vary by the genetic risk of AD and related dementias (ADD) is unknown. Methods This study included 148 659 older adults of white British ancestry (aged ≥60 years) participating in UK Biobank with no dementia, and self-reported poor health status at baseline. Polygenic risk scores (PRS) for ADD were calculated based on 64 genetic variants. Grip strength was measured by hand dynamometers. Results The hazard ratios (HR) of dementia (n  = 4 963) and AD (n  = 2 373) for high genetic risk of ADD were 2.36 (95% confidence interval [CI]: 2.15–2.59) and 3.00 (95% CI: 2.61–3.44), respectively, compared with low genetic risk. Compared with the bottom tertile of grip strength, the top tertile of grip strength had a hazard ratio (HR) of 0.69 (95% CI: 0.64–0.74) for incident dementia, and 0.74 (95% CI: 0.66–0.82) for incident AD, after adjustment for confounders and PRS for ADD. The risk of dementia and AD was lower with the top grip strength tertile within each level of genetic susceptibility to ADD. There was no evidence of multiplicative interaction between grip strength and genetic susceptibility to ADD for both dementia (p value:.241) and AD (p value:.314). Conclusions Older adults with higher PRS for ADD are at higher risk of developing dementia and AD. The risk of dementia and AD was lower in individuals with higher grip strength, regardless of their level of genetic susceptibility to ADD. [ABSTRACT FROM AUTHOR]

Background: Poor mental health is associated with obesity, but existing studies are either cross-sectional or have long time periods between measurements of mental health and weight. It is, therefore, unclear how small fluctuations in mental wellbeing within individuals predict bodyweight over short time periods, e.g. within the next month. Studying this could identify modifiable determinants of weight changes and highlight opportunities for early intervention. Methods: 2,133 UK adults from a population-based cohort completed monthly mental health and weight measurements using a mobile app over a period of 6–9 months. We used random intercept regression models to examine longitudinal associations of depressive symptoms, anxiety symptoms and stress with subsequent weight. In sub-group analyses, we included interaction terms of mental health variables with baseline characteristics. Mental health variables were split into "between-individual" measurements (= the participant's median score across all timepoints) and "within-individual" measurements (at each timepoint, the difference between the participant's current score and their median). Results: Within-individual variation in depressive symptoms predicted subsequent weight (0.045kg per unit of depressive symptom severity, 95% CI 0.021–0.069). We found evidence of a moderation effect of baseline BMI on the association between within-individual fluctuation in depressive symptoms and subsequent weight: The association was only apparent in those with overweight/obesity, and it was stronger in those with obesity than those with overweight (BMI<25kg/m2: 0.011kg per unit of depressive symptom severity [95% CI -0.017 to 0.039]; BMI 25–29.9kg/m2: 0.052kg per unit of depressive symptom severity [95%CI 0.010–0.094kg]; BMI≥30kg/m2: 0.071kg per unit of depressive symptom severity [95%CI 0.013–0.129kg]). We found no evidence for other interactions, associations of stress and anxiety with weight, or for a reverse direction of association. Conclusion: In this exploratory study, individuals with overweight or obesity were more vulnerable to weight gain following higher-than-usual (for that individual) depressive symptoms than individuals with a BMI<25kg/m2. [ABSTRACT FROM AUTHOR]

Background: Excess sedentary time (ST) is recognized as an important modifiable risk factor for coronary heart disease (CHD). However, whether the associations of genetic susceptibility with CHD incidence can be modified by replacing wearable‐device‐measured ST with physical activity (PA) is unknown. Objectives: To examine the associations of wearable‐device‐measured ST replaced by PA with incident CHD across strata of genetic susceptibility. Methods: This study included 77,500 White British (57% female) with valid wrist‐worn accelerometry and without prevalent CHD/stroke from UK Biobank. Genetic susceptibility to CHD was quantified through weighted polygenic risk scores for CHD based on 300 single‐nucleotide polymorphisms. Wrist‐worn accelerometer data were used to derive ST, light PA, and moderate‐to‐vigorous PA (MVPA). Results: Reallocation of 60 min/day of ST into the same amount of MVPA was associated with approximately 9% lower relative risk of CHD for all participants and across strata of genetic risk: replacement of 1 min/day of ST associated with <1% lower relative risk of CHD. No evidence of interaction (p: 0.784) was found between genetic risk and ST for CHD risk. Reallocating 60 min/day of ST into the same MVPA time was associated with greater absolute CHD risk reductions at high genetic risk (0.27%) versus low genetic risk (0.15%). Conclusions: Replacing any amount of ST with an equal amount of MVPA time is associated with a lower relative risk of CHD, irrespective of genetic susceptibility to CHD. Reductions in CHD absolute risk for replacing ST with MVPA are greater at high genetic risk versus low genetic risk. [ABSTRACT FROM AUTHOR]

Summary: Background: The association between adolescent time spent on social media use and body mass index z‐score (BMI z‐score) is unclear. Pathways of association and sex differences are also unclear. This study examined the association between time spent on social media use and BMI z‐score (primary objective) and potential explanatory pathways (secondary objective) for boys and girls. Methods: Data are from 5332 girls and 5466 boys aged 14 years in the UK Millennium Cohort Study. BMI z‐score was regressed on self‐reported time spent on social media use (h/day). Potential explanatory pathways explored included dietary intake, sleep duration, depressive symptoms, cyberbullying, body‐weight satisfaction, self‐esteem, and well‐being. Sex‐stratified multivariable linear regression and structural equation modelling were used to examine potential associations and explanatory pathways. Results: Using social media for ≥5 h/day (vs. <1 h/day) was positively associated with BMI z‐score for girls (β [95% CI]) (0.15 [0.06, 0.25]) (primary objective, multivariable linear regression). For girls, the direct association was attenuated when sleep duration (0.12 [0.02, 0.22]), depressive symptoms (0.12 [0.02, 0.22]), body‐weight satisfaction (0.07 [−0.02, 0.16]), and well‐being (0.11 [0.01, 0.20]) were included (secondary objective, structural equation modelling). No associations were observed for boys and potential explanatory pathway variables were not examined. Conclusions: In girls, high time spent on social media use (≥5 h/day) was positively associated with BMI z‐score, and this association was partially explained by sleep duration, depressive symptoms, body‐weight satisfaction, and well‐being. Associations and attenuations between a self‐reported summary variable of time spent on social media use and BMI z‐score were small. Further research should examine whether time spent on social media use is related to other adolescent health metrics. [ABSTRACT FROM AUTHOR]

Background: Sugar-sweetened beverages (SSBs) are the primary source of dietary added sugars in children, with high consumption commonly observed in more deprived areas where obesity prevalence is also highest. Associations between SSB consumption and obesity in children have been widely reported. In March 2016, a two-tier soft drinks industry levy (SDIL) on drinks manufacturers to encourage reformulation of SSBs in the United Kingdom was announced and then implemented in April 2018. We examined trajectories in the prevalence of obesity at ages 4 to 5 years and 10 to 11 years, 19 months after the implementation of SDIL, overall and by sex and deprivation. Methods and findings: Data were from the National Child Measurement Programme and included annual repeat cross-sectional measurement of over 1 million children in reception (4 to 5 years old) and year 6 (10 to 11 years old) in state-maintained English primary schools. Interrupted time series (ITS) analysis of monthly obesity prevalence data from September 2013 to November 2019 was used to estimate absolute and relative changes in obesity prevalence compared to a counterfactual (adjusted for temporal variations in obesity prevalence) estimated from the trend prior to SDIL announcement. Differences between observed and counterfactual estimates were examined in November 2019 by age (reception or year 6) and additionally by sex and deprivation quintile. In year 6 girls, there was an overall absolute reduction in obesity prevalence (defined as >95th centile on the UK90 growth charts) of 1.6 percentage points (PPs) (95% confidence interval (CI): 1.1, 2.1), with greatest reductions in the two most deprived quintiles (e.g., there was an absolute reduction of 2.4 PP (95% CI: 1.6, 3.2) in prevalence of obesity in the most deprived quintile). In year 6 boys, there was no change in obesity prevalence, except in the least deprived quintile where there was a 1.6-PP (95% CI: 0.7, 2.5) absolute increase. In reception children, relative to the counterfactual, there were no overall changes in obesity prevalence in boys (0.5 PP (95% CI: 1.0, −0.1)) or girls (0.2 PP (95% CI: 0.8, −0.3)). This study is limited by use of index of multiple deprivation of the school attended to assess individual socioeconomic disadvantage. ITS analyses are vulnerable to unidentified cointerventions and time-varying confounding, neither of which we can rule out. Conclusions: Our results suggest that the SDIL was associated with decreased prevalence of obesity in year 6 girls, with the greatest differences in those living in the most deprived areas. Additional strategies beyond SSB taxation will be needed to reduce obesity prevalence overall, and particularly in older boys and younger children. Trial registration: ISRCTN18042742. Nina T Rogers and colleagues investigate changes in the levels of obesity in children aged 4-5 years and 10-11 years, 19 months after the implementation of UK soft drinks industry levy. Author summary: Why was this study done?: In England, childhood obesity rates are high with around 10% of reception age children (4/5 years) and 20% of children in year 6 (10/11 years) recorded as living with obesity in 2020. Children who are obese are more likely to suffer from serious health problems including high blood pressure, type 2 diabetes, and depression in childhood and in later life. In March 2016, to tackle childhood obesity, the UK government announced there would be a soft drinks industry levy (SDIL) on manufacturers of soft drinks to incentivize them to reduce the sugar content of drinks. What did the researchers do and find?: We tracked changes in the levels of obesity in children in England from reception (ages 4/5 years) and year 6 (ages 10/11 years) over time between 2014 and 2020. This analysis involved comparing obesity levels 19 months following the SDIL with predicted obesity levels had the SDIL not happened according to gender of the child and school's area level of deprivation. The UK SDIL was associated with an 8% relative reduction in obesity levels in girls aged 10/11 years, equivalent to prevention of 5,234 cases of obesity per year in girls aged 10/11 years, alone. Reductions were greatest in girls whose school was in the 40% most deprived areas. No associations were found between the SDIL and changes in obesity levels in boys aged 10/11 years or younger children aged 4/5. What do these findings mean?: Our findings suggest that the UK SDIL led to positive health impacts in the form of reduced obesity levels in girls aged 10/11 years. Further strategies are needed to reduce obesity prevalence in primary school children overall, and particularly in older boys and younger children. [ABSTRACT FROM AUTHOR]

Introduction: Adults with overweight and obesity are vulnerable to weight gain and mental health deterioration during the COVID-19 pandemic. We developed a web-based, guided self-help intervention based on Acceptance and Commitment Therapy (ACT) that aims to support adults with overweight and obesity to prevent weight gain by helping them to manage their eating behaviours, be more physically active, and protect their emotional wellbeing ("SWiM-C"). SWiM-C is a guided self-help programme using non-specialist guides to enhance scalability and population reach while minimizing cost. This study evaluated the effect of SWiM-C on bodyweight, eating behaviour, physical activity, and mental wellbeing in adults with overweight and obesity over 4 months during the COVID-19 pandemic in the UK. Methods: We randomized adults (BMI ≥25 kg/m2) to SWiM-C or to a wait-list standard advice group. Participants completed outcome assessments online at baseline and 4 months. The primary outcome was self-measured weight; secondary outcomes were eating behaviour, physical activity, experiential avoidance/psychological flexibility, depression, anxiety, stress, and wellbeing. We estimated differences between study groups in change in outcomes from baseline to 4 months using linear regression, adjusted for outcome at baseline and the randomization stratifiers (BMI, sex). The trial was pre-registered (ISRCTN12107048). Results: 486 participants were assessed for eligibility; 388 participants were randomized (196 standard advice, 192 SWiM-C), and 324 were analysed. The adjusted difference in weight between SWiM-C and standard advice was −0.60 kg (−1.67 to 0.47, p = 0.27). SWiM-C led to improvements in uncontrolled eating (−3.61 [−5.94 to −1.28]), cognitive restraint (5.28 [2.81–7.75]), experiential avoidance (−3.39 [−5.55 to −1.23]), and wellbeing (0.13 [0.07–0.18]). Conclusions: SWiM-C improved several psychological determinants of successful weight management and had a protective effect on wellbeing during the pandemic. However, differences in weight and some other outcomes were compatible with no effect of the intervention, suggesting further refinement of the intervention is needed. [ABSTRACT FROM AUTHOR]

Purpose: Early puberty is associated with adverse health outcomes. To identify potential modifiable factors for puberty timing, we examined the associations of prepubertal childhood macronutrient intakes with puberty timing in boys and girls. Methods: In the Avon Longitudinal Study of Parents and Children, macronutrient intakes at age 6 years were predicted using random intercepts linear regression models of dietary data at 3, 4, 7 (assessed by food frequency questionnaires) and 7.5 years (by 3-day food diaries). Timings of puberty onset (Tanner stage 2 genital or breast (B2) development) and puberty completion (voice breaking (VB) or menarche) were calculated from annual parental and child reports at 8–17 years. Age at peak height velocity (PHV) was derived from repeated height measurements at 5–20 years. Linear regression models were fit to estimate the associations of total energy (TEI) and macronutrient intakes (carbohydrate, fat, protein) with puberty timing traits, adjusting for maternal and infant characteristics. Results: Among 3811 boys, higher TEI, but no macronutrient, was associated with earlier VB. Among 3919 girls, higher TEI was associated with earlier ages at B2, PHV, and menarche. Higher protein intake but not carbohydrate or fat intake (in energy partition models) and substitution of dietary protein for carbohydrate (in nutrient density and residual models) was associated with earlier B2, PHV, and menarche in girls. Findings were not attenuated on additional adjustment for body fat percentage during adolescence. Conclusions: These findings suggest habitual total energy intakes in children, and protein intakes in girls, as potential modifiable determinants of puberty timing. [ABSTRACT FROM AUTHOR]

Background: Current physical activity guidelines do not distinguish between activity accumulated in different behavioural domains but some studies suggest that occupational physical activity (OPA) may not confer health benefits and could even be detrimental. The purpose of this study was to investigate associations between OPA and mortality outcomes. Methods: From baseline (2006–2010), 460,901 UK Biobank participants (aged 40–69 years) were followed for a median 12.0 (IQR: 11.3–12.7) years. OPA was categorised by cross-tabulating degree of manual work and walking/standing work amongst those in paid employment (n = 267,765), and combined with categories of occupational status for those not in paid employment (n = 193,136). Cox proportional hazards models were used to estimate sex-stratified hazard ratios (HR) and 95% confidence intervals (CI) for mortality from all causes, CVD, and cancer by occupational group, and for working hours/week and non-occupational physical activity stratified by occupational group. Models included adjustment for age and a range of lifestyle, socio-economic and health-related covariates. Results: During 5,449,989 person-years of follow-up, 28,740 deaths occurred. Compared to those reporting no heavy manual or walking/standing work (e.g. sedentary office workers) and adjusting for covariates, retirement was associated with lower mortality in women (HR = 0.62, CI: 0.53–0.72) and men (HR = 0.80, CI: 0.71–0.90), whereas unemployment was associated with higher mortality in men only (HR = 1.24, CI: 1.07–1.45). Within the working population, there was no evidence of differences in all-cause, CVD or cancer mortality by OPA group when comparing those reporting higher levels of OPA to the lowest OPA reference group for both women and men. Working < 35 h/week versus 35–40 h/week was associated with lower mortality in women (HR = 0.85, CI: 0.79–0.92) and men (HR = 0.83, CI: 0.78–0.89), with no interaction by OPA. Non-occupational physical activity was associated with lower mortality in working women (HR = 0.89 per 5 kJ/day/kg, CI: 0.84–0.95) and men (HR = 0.87 per 5 kJ/day/kg, CI: 0.84–0.91), with no interaction by OPA group. Conclusions: Jobs classified as higher levels of OPA may not be as active as reported, or the types of physical activity performed in those jobs are not health-enhancing. Irrespective of OPA category or employment status, non-occupational physical activity appears to provide health benefits. [ABSTRACT FROM AUTHOR]

Background: Characteristics of the built environment, such as neighbourhood fast-food outlet exposure, are increasingly recognised as risk factors for unhealthy diet and obesity. Obesity also has a genetic component, with common genetic variants explaining a substantial proportion of population-level obesity susceptibility. However, it is not known whether and to what extent associations between fast-food outlet exposure and body weight are modified by genetic predisposition to obesity.Methods: We used data from the Fenland Study, a population-based sample of 12,435 UK adults (mean age 48.6 years). We derived a genetic risk score associated with BMI (BMI-GRS) from 96 BMI-associated single nucleotide polymorphisms. Neighbourhood fast-food exposure was defined as quartiles of counts of outlets around the home address. We used multivariable regression models to estimate the associations of each exposure, independently and in combination, with measured BMI, overweight and obesity, and investigated interactions.Results: We found independent associations between BMI-GRS and risk of overweight (RR = 1.34, 95% CI 1.23-1.47) and obesity (RR = 1.73, 95% CI 1.55-1.93), and between fast-food outlet exposure and risk of obesity (highest vs lowest quartile RR = 1.58, 95% CI 1.21-2.05). There was no evidence of an interaction of fast-food outlet exposure and genetic risk on BMI (P = 0.09), risk of overweight (P = 0.51), or risk of obesity (P = 0.27). The combination of higher BMI-GRS and highest fast-food outlet exposure was associated with 2.70 (95% CI 1.99-3.66) times greater risk of obesity.Conclusions: Our study demonstrated independent associations of both genetic obesity risk and neighbourhood fast-food outlet exposure with adiposity. These important drivers of the obesity epidemic have to date been studied in isolation. Neighbourhood fast-food outlet exposure remains a potential target of policy intervention to prevent obesity and promote the public's health. [ABSTRACT FROM AUTHOR]

Background: Sugar-sweetened beverage (SSB) consumption is positively associated with obesity, type 2 diabetes, and cardiovascular disease. The World Health Organization recommends that member states implement effective taxes on SSBs to reduce consumption. The United Kingdom Soft Drinks Industry Levy (SDIL) is a two-tiered tax, announced in March 2016 and implemented in April 2018. Drinks with ≥8 g of sugar per 100 ml (higher levy tier) are taxed at £0.24 per litre, drinks with ≥5 to <8 g of sugar per 100 ml (lower levy tier) are taxed at £0.18 per litre, and drinks with <5 g sugar per 100 ml (no levy) are not taxed. Milk-based drinks, pure fruit juices, drinks sold as powder, and drinks with >1.2% alcohol by volume are exempt. We aimed to determine if the announcement of the SDIL was associated with anticipatory changes in purchases of soft drinks prior to implementation of the SDIL in April 2018. We explored differences in the volume of and amount of sugar in household purchases of drinks in each levy tier at 2 years post announcement.Methods and Findings: We used controlled interrupted time series to compare observed changes associated with the announcement of the SDIL to the counterfactual scenario of no announcement. We used data from Kantar Worldpanel, a commercial household purchasing panel with approximately 30,000 British members that includes linked nutritional data on purchases. We conducted separate analyses for drinks liable for the SDIL in the higher, lower, and no-levy tiers controlling with household purchase volumes of toiletries. At 2 years post announcement, there was no difference in volume of or sugar from purchases of higher-levy-tier drinks compared to the counterfactual of no announcement. In contrast, a reversal of the existing upward trend in volume (ml) of and amount of sugar (g) in purchases of lower-levy-tier drinks was seen. These changes led to a -96.1 ml (95% confidence interval [CI] -144.2 to -48.0) reduction in volume and -6.4 g (95% CI -9.8 to -3.1) reduction in sugar purchased in these drinks per household per week. There was a reversal of the existing downward trend in the amount of sugar in household purchases of the no-levy drinks but no change in volume purchased. At 2 years post announcement, these changes led to a 6.1 g (95% CI 3.9-8.2) increase in sugar purchased in these drinks per household per week. There was no evidence that volume of or amount of sugar in purchases of all drinks combined was different from the counterfactual. This is an observational study, and changes other than the SDIL may have been responsible for the results reported. Purchases consumed outside of the home were not accounted for.Conclusions: The announcement of the UK SDIL was associated with reductions in volume and sugar purchased in lower-levy-tier drinks before implementation. These were offset by increases in sugar purchased from no-levy drinks. These findings may reflect reformulation of drinks from the lower levy to no-levy tier with removal of some but not all sugar, alongside changes in consumer attitudes and beliefs.Trial Registration: ISRCTN Registry ISRCTN18042742. [ABSTRACT FROM AUTHOR]

Background: Less than 20% of adolescents globally meet recommended levels of physical activity, and not meeting these recommended levels is associated with social disadvantage and rising disease risk. The determinants of physical activity in adolescents are multilevel and poorly understood, but the school's social environment likely plays an important role. We conducted a cluster randomised controlled trial to assess the effectiveness of a school-based programme (GoActive) to increase moderate-to-vigorous physical activity (MVPA) among adolescents.Methods and Findings: Non-fee-paying, co-educational schools including Year 9 students in the UK counties of Cambridgeshire and Essex were eligible for inclusion. Within participating schools (n = 16), all Year 9 students were eligible and invited to participate. Participants were 2,862 13- to 14-year-olds (84% of eligible students). After baseline assessment, schools were computer-randomised, stratified by school-level pupil premium funding (below/above county-specific median) and county (control: 8 schools, 1,319 participants, mean [SD] participants per school n = 165 [62]; intervention: 8 schools, 1,543 participants, n = 193 [43]). Measurement staff were blinded to allocation. The iteratively developed, feasibility-tested 12-week intervention, aligned with self-determination theory, trained older adolescent mentors and in-class peer-leaders to encourage classes to conduct 2 new weekly activities. Students and classes gained points and rewards for engaging in any activity in or out of school. The primary outcome was average daily minutes of accelerometer-assessed MVPA at 10-month follow-up; a mixed-methods process evaluation evaluated implementation. Of 2,862 recruited participants (52.1% male), 2,167 (76%) attended 10-month follow-up measurements; we analysed the primary outcome for 1,874 participants (65.5%). At 10 months, there was a mean (SD) decrease in MVPA of 8.3 (19.3) minutes in the control group and 10.4 (22.7) minutes in the intervention group (baseline-adjusted difference [95% confidence interval] -1.91 minutes [-5.53 to 1.70], p = 0.316). The programme cost £13 per student compared with control; it was not cost-effective. Overall, 62.9% of students and 87.3% of mentors reported that GoActive was fun. Teachers and mentors commented that their roles in programme delivery were unclear. Implementation fidelity was low. The main methodological limitation of this study was the relatively affluent and ethnically homogeneous sample.Conclusions: In this study, we observed that a rigorously developed school-based intervention was no more effective than standard school practice at preventing declines in adolescent physical activity. Interdisciplinary research is required to understand educational-setting-specific implementation challenges. School leaders and authorities should be realistic about expectations of the effect of school-based physical activity promotion strategies implemented at scale.Trial Registration: ISRCTN Registry ISRCTN31583496. [ABSTRACT FROM AUTHOR]

Background: UK Biobank is a large prospective cohort study containing accelerometer-based physical activity data with strong validity collected from 100,000 participants approximately 5 years after baseline. In contrast, the main cohort has multiple self-reported physical behaviours from > 500,000 participants with longer follow-up time, offering several epidemiological advantages. However, questionnaire methods typically suffer from greater measurement error, and at present there is no tested method for combining these diverse self-reported data to more comprehensively assess the overall dose of physical activity. This study aimed to use the accelerometry sub-cohort to calibrate the self-reported behavioural variables to produce a harmonised estimate of physical activity energy expenditure, and subsequently examine its reliability, validity, and associations with disease outcomes. Methods: We calibrated 14 self-reported behavioural variables from the UK Biobank main cohort using the wrist accelerometry sub-cohort (n = 93,425), and used published equations to estimate physical activity energy expenditure (PAEESR). For comparison, we estimated physical activity based on the scoring criteria of the International Physical Activity Questionnaire, and by summing variables for occupational and leisure-time physical activity with no calibration. Test-retest reliability was assessed using data from the UK Biobank repeat assessment (n = 18,905) collected a mean of 4.3 years after baseline. Validity was assessed in an independent validation study (n = 98) with estimates based on doubly labelled water (PAEEDLW). In the main UK Biobank cohort (n = 374,352), Cox regression was used to estimate associations between PAEESR and fatal and non-fatal outcomes including all-cause, cardiovascular diseases, respiratory diseases, and cancers. Results: PAEESR explained 27% variance in gold-standard PAEEDLW estimates, with no mean bias. However, error was strongly correlated with PAEEDLW (r = −.98; p < 0.001), and PAEESR had narrower range than the criterion. Test-retest reliability (Λ =.67) and relative validity (Spearman =.52) of PAEESR outperformed two common approaches for processing self-report data with no calibration. Predictive validity was demonstrated by associations with morbidity and mortality, e.g. 14% (95%CI: 11–17%) lower mortality for individuals meeting lower physical activity guidelines. Conclusions: The PAEESR variable has good reliability and validity for ranking individuals, with no mean bias but correlated error at individual-level. PAEESR outperformed uncalibrated estimates and showed stronger inverse associations with disease outcomes. [ABSTRACT FROM AUTHOR]

Background: The advent of very large cohort studies (n > 500 000) has given rise to prospective analyses of health outcomes being undertaken after short (<4 years) follow-up periods. However, these studies are potentially at risk of reverse causality bias. We investigated differences in the associations between self-reported physical activity and all-cause and cardiovascular disease (CVD) mortality, and incident CVD, using different follow-up time cut-offs and methods to account for reverse causality bias.Methods: Data were from n = 452 933 UK Biobank participants, aged 38-73 years at baseline. Median available follow-up time was 7 years (for all-cause and CVD mortality) and 6.1 years (for incident CVD). We additionally analysed associations at 1-, 2- and 4-year cut-offs after baseline. We fit up to four models: (1) adjusting for prevalent CVD and cancer, (2) excluding prevalent disease, (3) and (4) Model 2 excluding incident cases in the first 12 and 24 months, respectively.Results: The strength of associations decreased as follow-up time cut-off increased. For all-cause mortality, Model 1 hazard ratios were 0.73 (0.69-0.78) after 1 year and 0.86 (0.84-0.87) after 7 years. Associations were weaker with increasing control for possible reverse causality. After 7-years follow-up, the hazard ratios were 0.86 (0.84-0.87) and 0.88 (0.86-0.90) for Models 1 and 4, respectively. Associations with CVD outcomes followed similar trends.Conclusions: As analyses with longer follow-up times and increased control for reverse causality showed weaker associations, there are implications for the decision about when to analyse a cohort study with ongoing data collection, the interpretation of study results and their contribution to meta-analyses. [ABSTRACT FROM AUTHOR]

Background Little is known about changes in blood fatty acid compositions over time and the correlates of any changes in a general population. Objective The aim of this study was to estimate changes in 27 individual plasma phospholipid fatty acids and fatty acid groups over time, and to identify potential correlates of these changes. Methods Plasma phospholipid fatty acids were profiled at 3 time-points (1993–1997, 1998–2000, 2004–2011) among 722 participants in the European Prospective Investigation into Cancer and Nutrition-Norfolk Study, UK. Linear regression models were used to estimate both 1) mean changes over time in 27 individual fatty acids and 8 prespecified fatty acid groups and 2) associations of changes in dietary and lifestyle factors with changes in the 8 fatty acid groups, mutually adjusted for dietary/lifestyle factors and other confounders. The prespecified fatty acid groups were odd-chain saturated fatty acids (SFAs), even-chain SFAs, very-long-chain SFAs, marine n–3 polyunsaturated fatty acids (PUFAs), plant n–3 PUFA, n–6 PUFAs, monounsaturated fatty acids (MUFAs), and trans-fatty acids (TFAs). Results Adjusted for confounders, fatty acid concentrations decreased for odd-chain SFAs (annual percentage difference in mol percentage: −0.63%), even-chain SFAs (−0.05%), n–6 PUFAs (−0.25%), and TFAs (−7.84%). In contrast, concentrations increased for marine n–3 PUFAs (1.28%) and MUFAs (0.45%), but there were no changes in very-long-chain SFAs or plant n–3 PUFA. Changes in fatty acid levels were associated with consumption of different food groups. For example, a mean 100 g/d increase in fatty fish intake was associated with a 19.3% greater annual increase in marine n–3 PUFAs. Conclusions Even-chain SFAs and TFAs declined and marine n–3 PUFAs increased over time. These changes were partially explained by changes in dietary habits, and could potentially help interpret associations of baseline fatty acid composition with future disease risk. [ABSTRACT FROM AUTHOR]

Background: Higher grip strength (GS) is associated with lower mortality risk. However, whether this association is independent of adiposity is uncertain. Objective: The purpose of this study was to examine the associations between GS, adiposity, and mortality. Design: The UK Biobank study is an ongoing prospective cohort of .0.5 million UK adults aged 40-69 y. Baseline data collection (2006-2010) included measurements of GS and adiposity indicators, including body mass index (BMI; in kg/m²). Age- and sexspecific GS quintiles were used. BMI was classified according to clinical cutoffs. Results: Data from 403,199 participants were included in analyses. Over a median 7.0-y of follow-up, 8287 all-cause deaths occurred. The highest GS quintile had 32% (95% CI: 26%, 38%) and 25% (95% CI: 16%, 33%) lower all-cause mortality risks for men and women, respectively, compared with the lowest GS quintile, after adjustment for confounders and BMI. Obesity class II (BMI $35) was associated with a greater all-cause mortality risk. The highest GS quintile and obesity class II category showed relatively higher all-cause mortality hazards (not statistically significant in men) than the highest GS quintile and the normal weight category; however, the increased risk was relatively lower than the risk for the lowest GS quintile and obesity class II category. All-cause mortality risks were generally lower for obese but stronger individuals than for nonobese but weaker individuals. Similar patterns of associations were observed for cardiovascular mortality. Conclusions: Lower grip strength and excess adiposity are both independent predictors of higher mortality risk. The higher mortality risk associated with excess adiposity is attenuated, although not completely attenuated, by greater GS. Interventions and policies should focus on improving the muscular strength of the population regardless of their degree of adiposity. [ABSTRACT FROM AUTHOR]

Purpose: Leisure screen time, including TV viewing, is associated with increased mortality risk. We estimated the all-cause mortality risk reductions associated with substituting leisure screen time with different discretionary physical activity types, and the change in mortality incidence associated with different substitution scenarios. Methods: A total of 423,659 UK Biobank participants, without stroke, myocardial infarction, or cancer history, were followed for 7.6 (1.4) yr, median (interquartile range [IQR]). They reported leisure screen time (TV watching and home computer use) and leisure/home activities, categorized as daily life activities (walking for pleasure, light do-it-yourself [DIY], and heavy DIY) and structured exercise (strenuous sports and other exercises). Isotemporal substitution modeling in Cox regression provided hazard ratios (95% confidence intervals) for all-cause mortality when substituting screen time (30 min⋅d-1) with different discretionary activity types of the same duration. Potential impact fractions estimated the proportional change in mortality incidence associated with different substitution scenarios. Results: During 3,202,105 person-years of follow-up, 8928 participants died. Each 30-min⋅d-1 difference in screen time was associated with lower mortality hazard when modeling substitution of screen time by an equal amount of daily life activities (0.95, 0.94-0.97), as well as structured exercise (0.87, 0.84-0.90). Reallocations from screen time into specific activity subtypes suggested different reductions in mortality hazard: walking for pleasure (0.95, 0.92-0.98), light DIY (0.97, 0.94-1.00), heavy DIY (0.93, 0.90-0.96), strenuous sports (0.87, 0.79-0.95), and other exercises (0.88, 0.84-0.91). The lowest hazard estimates were found when modeling replacement of TV viewing. Potential impact fractions ranged from 4.3% (30-min⋅d-1 substitution of screen time into light DIY) to 14.9% (TV viewing into strenuous sports). Conclusion: Substantial public health benefits could be gained by replacing small amounts of screen time with daily life activities and structured exercise. Daily life activities may provide feasible screen time alternatives, if structured exercise is initially too ambitious. [ABSTRACT FROM AUTHOR]

Background: It is difficult to compare accelerometer-derived estimates of moderate-to-vigorous physical activity (MVPA) between studies due to differences in data processing procedures. We aimed to evaluate the effects of accelerometer processing options on total and bout-accumulated time spent in MVPA in adults. Methods: 267 participants from the ProActive Trial provided 1236 days of valid physical activity (PA) data, collected using a 5-s epoch with ActiGraph GT1M accelerometers. We integrated data over 5-s to 60-s epoch lengths (EL) and applied two-level mixed effects regression models to MVPA time, defined using 1500 to 2500 counts/minute (cpm) cut-points (CP) and bout durations (BD) from 1 to 15 min. Results: Total MVPA time was lower on longer EL and higher CP (47 vs 26 min/day and 26 vs 5 min/day on 1500 vs 2500 cpm on 5-s and 60-s epoch, respectively); this could be approximated as MVPA = exp[2.197 + 0.279*log(CP) + 6.120*log(EL) - 0.869*log(CP)*log(EL)] with an 800 min/day wear-time. In contrast, EL was positively associated with time spent in bout-accumulated MVPA; the approximating equation being MVPA = exp[54.679 - 6.268*log(CP) + 6.387*log(EL) - 10.000*log(BD) - 0.162*log(EL)*log(BD) - 0.626*log(CP)*log(EL) + 1.033*log(CP)*log(BD)]. BD and CP were inversely associated with MVPA, with higher values attenuating the influence of EL. Conclusions: EL, CP and BD interact to influence estimates of accelerometer-determined MVPA. In general, higher CP and longer BD result in lower MVPA but the direction of association for EL depends on BD. Reporting scaling coefficients for these key parameters across their frequently used ranges would facilitate comparisons of population-level accelerometry estimates of MVPA. [ABSTRACT FROM AUTHOR]

Background Little is known about preschool-aged children's levels of physical activity (PA) over the course of the day. Using time-stamped data, we describe the levels and patterns of PA in a population-based sample of four-year-old British children. Methods Within the Southampton Women's Survey the PA levels of 593 4-year-old children (51% female) were measured using (Actiheart) accelerometry for up to 7 days. Three outcome measures: minutes spent sedentary (<20 cpm); in light (LPA:≥20 - 399 cpm) and in moderate-to-vigorous activity (MVPA:≥400 cpm) were derived. Average daily activity levels were calculated and then segmented across the day (morning, afternoon and evening). MVPA was log-transformed. Two-level random intercept models were used to analyse associations between activity level and temporal and demographic factors. Results Children were active for 67% (mean 568.5 SD 79.5 minutes) of their daily registered time on average, with 88% of active time spent in LPA. All children met current UK guidelines of 180 minutes of daily activity. There were no differences in children's average daily levels of sedentary activity and LPA by temporal and demographic factors: differences did emerge when activity was segmented across the day. Sex differences were largest in the morning, with girls being more sedentary, spending fewer minutes in LPA and 18% less time in MVPA than boys. Children were more sedentary and less active (LPA and MVPA) in the morning if they attended childcare full-time compared to part-time, and on weekend mornings compared to weekdays. The reverse was true for weekend afternoons and evenings. Children with more educated mothers were less active in the evenings. Children were less sedentary and did more MVPA on summer evenings compared to winter evenings. Conclusions Preschool-aged children meet current physical activity guidelines, but with the majority of their active time spent in LPA, investigation of the importance of activity intensity in younger children is needed. Activity levels over the day differed by demographic and temporal factors, highlighting the need to consider temporality in future interventions. Increasing girls' morning activity and providing opportunities for daytime activity in winter months may be worthwhile. [ABSTRACT FROM AUTHOR]

Background: Participation in higher intensity activity (i.e. vigorous physical activity [VPA]) appears more consistently associated with lower adiposity, unfortunately little is known about the nature and patterns of VPA participation in children. Objective: To examine the volume and patterns of vigorous and sedentary activity during different segments of the week (weekend, school-based and out-of-school). We also investigated differences by sex, socioeconomic status (SES) and weight status. Design: A cross-sectional study including 1568 UK children aged 9-10 years. Outcome measures: Sedentary activity (mins), total activity (counts/min) and VPA (mins) were measured by accelerometry. Using a series of 2 level mixed effects linear regression models we tested differences across the segmented week (school time [0900-1500] vs. out-of-school time [0700-0900 & 1500-2100]; and weekday vs. weekend); all models were adjusted for sex, weight status (gender- and age-specific body mass index [BMI] cut points), SES, age and accelerometer registered wear time. Results: Boys and girls accumulated higher VPA out-of-school compared to during school (boys mean ± SD 16.9 ± 9.6 vs 12.6 ± 5.8; girls, 13.1 ± 7.7 vs 8.2 ± 4.0, both p < 0.001); but there were no differences for weekday v weekend VPA (p > 0.05). Less time was spent sedentary on weekdays compared to weekends (p < 0.001). Although boys were more physically active and girls accumulated more sedentary time, the overall pattern in which their physical activity intensity varied across the various day segments was similar when stratified by weight status and SES; and large volumes of sedentary time were observed each hour across the day. Conclusions: The promotion of VPA during the weekend may hold the greatest promise for increasing VPA. Interventions aimed at increasing physical activity in 9-10 year old children should aim to target all children independent of sex, SES or weight status. [ABSTRACT FROM AUTHOR]

Summary Background: Previous work has suggested that the long-term regular use of inhaled b [sub 2]-agonist bronchodilators might lead to a deterioration in asthma control. The aim of TRUST (The Regular Use of Salbutamol Trial) was to study the effects of regular use of inhaled salbutamol, the most widely prescribed bronchodilator in the UK, on the control of asthma.Methods: A randomised, double-blind, placebo-controlled trial was undertaken in 983 patients with asthma being treated at least twice a week with short-acting beta[sub 2]-agonist, alone or in combination with inhaled steroids (2 mg or less) daily. Patients were aged 18 years and over and were recruited from 115 general practices in the UK. 90% (881) of the patients used inhaled corticosteroid therapy, and all patients continued to use their usual inhaled b [sub 2]-agonist for symptomatic relief. Patients were randomised to receive 400 mg salbutamol or matched placebo via a Diskhaler four times per day for 12 months. The primary outcome measure was rate of exacerbations of asthma, with criteria based on data from diary cards completed daily by each patient, treatment with additional corticosteroids, or both.Findings: There were no differences in the annual rate, timing, or duration of exacerbations between the two groups. The mean morning peak expiratory flow was similar for the two groups. The mean evening peak expiratory flow (p<0.001) and the diurnal variation (p<0.001) were greater, and the use of rescue bronchodilator was less (p<0.001), in the group receiving regular salbutamol.Interpretation: There was no evidence that regular use of inhaled salbutamol 400 mg four times daily for a year increased the exacerbation rate of asthma in the population studied. [ABSTRACT FROM AUTHOR]

Background: Dietary inequalities between population groups are common with older and more affluent individuals tending to have healthier diets. Differential responses to health interventions may exacerbate inequalities. Changing what foods are displayed at supermarket checkouts is one intervention that has the potential to change diets. The aim of this study was to assess whether differences in purchases of common checkout foods from supermarkets with different checkout food policies varied according to age group and social grade. Methods: We analysed annual household purchase data for 2013–17 from nine leading UK supermarkets, split according to age of the main household shopper and household social grade. Checkout food policies were categorised as clear and consistent, vague or inconsistent, and none. Policies were heterogeneous but all included removal of confectionery and/or chocolate from checkouts. Mixed effects linear regression models were used to assess differences in purchases of common checkout foods (sugary confectionery, chocolate and potato crisps) by checkout food policy and whether these varied by age group or occupational social grade. Results: Relative to supermarkets with no checkout food policy, 14% (95% CI: 4–22%) fewer purchases of common checkout foods per household per percentage market share were made in supermarkets with a clear and consistent policy. Adjusted mean numbers of purchases were higher in older age groups than the youngest, but there were no differences between the highest and other social grades. There were significant interactions between checkout food policy and both age group and social grade. In supermarkets with clear and consistent policies, 23% (6–36%), 20% (2–34%), and 23% (7–37%) fewer purchases were made in age groups 45–54, 55–64 and 65+ years respectively, compared to all groups combined. In supermarkets with clear and consistent policies, there were 21% (4–35%), 26% (9–39%) and 21% (3–35%) fewer purchases made by households in the highest two and lowest social grades respectively, compared to all groups combined. Conclusions: Households with older main shoppers and those in the most and least affluent social grades may be most responsive to supermarket checkout food policies. As older and more affluent groups tend to have healthier diets overall, it is unlikely that supermarket checkout food policies contribute to greater dietary equity. [ABSTRACT FROM AUTHOR]

Reports the clinical and cost results of a study to compare the long-term effects of percutaneous transluminal coronary angioplasty and coronary-artery bypass grafting among patients with angina in whom equivalent revascularization could be achieved by either treatment method. The Randomised Intervention Treatment of Angina trial (RITA-1) being a multicenter study of coronary heart disease patients in Great Britain; Methods; Findings; Interpretation.

The article investigates the effect of intensive multifactorial therapy in individuals with type 2 diabetes through a cluster-randomised trial in Denmark and Great Britain. Patients aged 40 to 69 are screened, followed by routine care and intensive treatment. It was found that improvements in cardiovascular risk factors are better in intensive treatment group than in routine care group. Managing the patients is considered to be associated with a reduction in cardiovascular events and death.

Objective: To examine the associations of muscle strength and genetic risk for stroke with stroke incidence., Participants and Methods: We included 284,767 white British participants of UK Biobank without genetic relatedness and stroke or myocardial infarction at baseline between March 13, 2006, and October 1, 2010. Genetic risk was assessed with polygenic risk scores, calculated by summing the risk-increasing alleles, weighted by the effect estimates. Muscle strength was assessed through grip strength tests by hand dynamometers. Incidence of overall (n= 4008), ischemic (n= 3031), and hemorrhagic (n=1073) stroke was adjudicated during 11.5-year follow-up., Results: Compared with the bottom muscle strength tertile, hazard ratios (95% CI) of stroke were 0.81 (0.75 to 0.87) and 0.76 (0.71 to 0.82) for the middle and top muscle strength tertiles, respectively, after adjustment for confounders and genetic risk; higher genetic risk was independently associated with higher stroke incidence. Stroke hazards for the top muscle strength tertile were consistently lower across genetic risk strata, with no evidence of interaction. Compared with individuals with high muscle strength and low genetic risk, stroke hazards were higher for individuals who had medium or high genetic risk combined with low or medium muscle strength but not for those who had medium genetic risk but high muscle strength. Associations were similar for ischemic and hemorrhagic stroke (although CIs were inconclusive for some of the associations)., Conclusion: Higher muscle strength was associated with lower stroke incidence in all individuals, including those with high genetic susceptibility. The increased genetic risk of overall and ischemic stroke was partly attenuated through increased muscle strength., (Copyright © 2021 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.)

Aims/hypothesis: This randomised controlled trial was performed in India and the UK in people with prediabetes to study whether mobile phone short message service (SMS) text messages can be used to motivate and educate people to follow lifestyle modifications, to prevent type 2 diabetes., Methods: The study was performed in people with prediabetes (n = 2062; control: n = 1031; intervention: n = 1031) defined by HbA 1c ≥42 and ≤47 mmol/mol (≥6.0% and ≤6.4%). Participants were recruited from public and private sector organisations in India (men and women aged 35-55 years) and by the National Health Service (NHS) Health Checks programme in the UK (aged 40-74 years without pre-existing diabetes, cardiovascular disease or kidney disease). Allocation to the study groups was performed using a computer-generated sequence (1:1) in India and by stratified randomisation in permuted blocks in the UK. Investigators in both countries remained blinded throughout the study period. All participants received advice on a healthy lifestyle at baseline. The intervention group in addition received supportive text messages using mobile phone SMS messages 2-3 times per week. Participants were assessed at baseline and at 6, 12 and 24 months. The primary outcome was conversion to type 2 diabetes and secondary outcomes included anthropometry, biochemistry, dietary and physical activity changes, blood pressure and quality of life., Results: At the 2 year follow-up (n = 2062; control: n = 1031; intervention: n = 1031), in the intention-to-treat population the HR for development of type 2 diabetes calculated using a discrete-time proportional hazards model was 0.89 (95% CI 0.74, 1.07; p = 0.22). There were no significant differences in the secondary outcomes., Conclusions/interpretation: This trial in two countries with varied ethnic and cultural backgrounds showed no significant reduction in the progression to diabetes in 2 years by lifestyle modification using SMS messaging., Trial Registration: The primary study was registered on www.ClinicalTrials.gov (India, NCT01570946; UK, NCT01795833)., Funding: The study was funded jointly by the Indian Council for Medical Research and the UK Medical Research Council.

Background: Most risk models for cancer are either specific to individual cancers or include complex or predominantly non-modifiable risk factors., Methods: We developed lifestyle-based models for the five cancers for which the most cases are potentially preventable through lifestyle change in the UK (lung, colorectal, bladder, kidney, and esophageal for men and breast, lung, colorectal, endometrial, and kidney for women). We selected lifestyle risk factors from the European Code against Cancer and obtained estimates of relative risks from meta-analyses of observational studies. We used mean values for risk factors from nationally representative samples and mean 10-year estimated absolute risks from routinely available sources. We then assessed the performance of the models in 23,768 participants in the EPIC-Norfolk cohort who had no history of the five selected cancers at baseline., Results: In men, the combined risk model showed good discrimination [AUC, 0.71; 95% confidence interval (CI), 0.69-0.73] and calibration. Discrimination was lower in women (AUC, 0.59; 95% CI, 0.57-0.61), but calibration was good. In both sexes, the individual models for lung cancer had the highest AUCs (0.83; 95% CI, 0.80-0.85 for men and 0.82; 95% CI, 0.76-0.87 for women). The lowest AUCs were for breast cancer in women and kidney cancer in men., Conclusions: The discrimination and calibration of the models are both reasonable, with the discrimination for individual cancers comparable or better than many other published risk models., Impact: These models could be used to demonstrate the potential impact of lifestyle change on risk of cancer to promote behavior change., (©2018 American Association for Cancer Research.)

Background: In response to public concerns and campaigns, some United Kingdom supermarkets have implemented policies to reduce less-healthy food at checkouts. We explored the effects of these policies on purchases of less-healthy foods commonly displayed at checkouts., Methods and Findings: We used a natural experimental design and two data sources providing complementary and unique information. We analysed data on purchases of small packages of common, less-healthy, checkout foods (sugary confectionary, chocolate, and potato crisps) from 2013 to 2017 from nine UK supermarkets (Aldi, Asda, Co-op, Lidl, M&S, Morrisons, Sainsbury's, Tesco, and Waitrose). Six supermarkets implemented a checkout food policy between 2013 and 2017 and were considered intervention stores; the remainder were comparators. Firstly, we studied the longitudinal association between implementation of checkout policies and purchases taken home. We used data from a large (n ≈ 30,000) household purchase panel of food brought home to conduct controlled interrupted time series analyses of purchases of less-healthy common checkout foods from 12 months before to 12 months after implementation. We conducted separate analyses for each intervention supermarket, using others as comparators. We synthesised results across supermarkets using random effects meta-analyses. Implementation of a checkout food policy was associated with an immediate reduction in four-weekly purchases of common checkout foods of 157,000 (72,700-242,800) packages per percentage market share-equivalent to a 17.3% reduction. This decrease was sustained at 1 year with 185,100 (121,700-248,500) fewer packages purchased per 4 weeks per percentage market share-equivalent to a 15.5% reduction. The immediate, but not sustained, effect was robust to sensitivity analysis. Secondly, we studied the cross-sectional association between checkout food policies and purchases eaten without being taken home. We used data from a smaller (n ≈ 7,500) individual purchase panel of food bought and eaten 'on the go'. We conducted cross-sectional analyses comparing purchases of common checkout foods in 2016-2017 from supermarkets with and without checkout food policies. There were 76.4% (95% confidence interval 48.6%-89.1%) fewer annual purchases of less-healthy common checkout foods from supermarkets with versus without checkout food policies. The main limitations of the study are that we do not know where in the store purchases were selected and cannot determine the effect of changes in purchases on consumption. Other interventions may also have been responsible for the results seen., Conclusions: There is a potential impact of checkout food polices on purchases. Voluntary supermarket-led activities may have public health benefits., Competing Interests: The authors have declared that no competing interests exist.