Background Previous studies revealed inconsistent findings regarding the association between sleep duration and all-cause and disease-specific mortality. This study aimed to clarify the association of sleep duration with mortality using a large population-based prospective cohort study from the USA. Methods We used data from the National Health Interview Survey (2004–2014) linked to National Death Index records to 31 December 2015. A total of 284 754 participants aged ≥18 years were included. Self-reported sleep duration (average time slept in a 24-hour period) was categorised into seven groups: ≤4 hours, 5 hours, 6 hours, 7 hours (reference), 8 hours, 9 hours and ≥10 hours. Study outcomes included all-cause, cardiovascular disease-specific and cancer-specific mortality. Cox proportional hazards models were used to examine the association between sleep duration and mortality. Results During a median follow-up of 5.25 years, we identified 20 872 deaths, of which 4 129 were cardiovascular disease-related and 5 217 were cancer-related. Compared with 7 hours/day of sleep, both short and long sleep durations were associated with an increased risk of all-cause mortality (≤4 hours: HR=1.46, 95% CI=1.33–1.61; 5 hours: HR=1.22, 95% CI=1.13–1.32; 6 hours: HR=1.10, 95% CI=1.05–1.17; 8 hours: HR=1.22, 95% CI=1.17–1.28; 9 hours: HR=1.41, 95% CI=1.31–1.51; ≥10 hours: HR=2.00, 95% CI=1.88–2.13). Similar results were observed for cardiovascular disease-specific and cancer-specific mortality. Conclusions Our study indicates that both short (≤6 hours/day) and long (≥8 hours/day) sleep durations increase the risk of mortality compared with sleep of 7 hours/day. A normal sleep duration (about 7 hours) every day is recommended for health benefits.

Sarcopenia and knee osteoarthritis are common age-related diseases that have become important public health issues worldwide. Few studies have reported the association between muscle mass loss and knee osteoarthritis. This may be due to the high level of heterogeneity between studies stemming from different definitions of muscle mass loss. The systematic searches were carried out in PubMed and Web of Science from the inception of the databases until 13 January 2023, by two independent researchers. Pooled odds ratios (ORs) for overall and subgroup analyses were obtained using either a random effects model (I² >50%) or fixed effects model (I² ≤50%) in Stata. Of the 1,606 studies identified, we ultimately included 12 articles on the association between muscle mass and knee osteoarthritis (prospective: n = 5; cross-sectional: n = 7). Low-quality evidence indicated that low muscle mass index and sarcopenic obesity increase the odds of knee osteoarthritis (low muscle mass index OR: 1.36, 95% CI: 1.13-1.64; sarcopenic obesity OR: 1.78, 95% CI: 1.35-2.34). However, no association was observed between general sarcopenia or low muscle mass with knee osteoarthritis. This systematic review and meta-analysis revealed that low muscle mass index and sarcopenic obesity were associated with an increased risk of developing knee osteoarthritis.

Background: The recently published “Life’s Essential 8” (LE8) by the American Heart Association has overcome some limitations in evaluating cardiovascular health (CVH) in the previous “Life’s Simple 7.” Objective: We aimed to examine the secular trends in CVH, as assessed by the LE8, in US adults from 2005 to 2018. Methods: Using cross-sectional data from the National Health and Nutrition Examination Survey between 2005-2006 and 2017-2018, we calculated the age-standardized mean scores of overall CVH and each of the LE8 components, where a higher score (range 0-100 points) means a better health status. A total of 21,667 adults aged 20-79 years were included in this analysis. Results: The overall CVH did not significantly change between 2005-2006 and 2017-2018 (65.5, 95% CI 63.9-67.1 to 65.0, 95% CI 62.8-67.1; P=.82). The individual metrics did not significantly change for diet (41.0, 95% CI 38.0-43.9 to 41.5, 95% CI 36.5-46.6; P=.94), physical activity (57.5, 95% CI 53.0-61.9 to 53.0, 95% CI 48.7-57.3; P=.26), and blood pressure (68.4, 95% CI 65.2-71.5 to 68.6, 95% CI 65.3-71.9, P=.35), improved for nicotine exposure (64.7, 95% CI 61.1-68.4 to 71.9, 95% CI 67.7-76.2; P<.001), sleep health (83.7, 95% CI 81.6-85.7 to 84.1, 95% CI 81.2-87.1; P=.006), and blood lipids (61.6, 95% CI 59.1-64.0 to 67.0, 95% CI 63.5-70.4; P<.001), and worsened for BMI (63.4, 95% CI 59.7-67.1 to 56.2, 95% CI 52.5-59.9; P<.001) and blood glucose (83.9, 95% CI 82.4-85.4 to 77.4, 95% CI 74.5-80.3; P<.001). Conclusions: According to the LE8, the overall CVH did not change among US adults from 2005 to 2018, as well as 3 components (diet, physical activity, and blood pressure). Other metrics such as nicotine exposure, blood lipids, and sleep health improved, while BMI and blood glucose deteriorated over time.

It is unclear whether physical activity and sedentary behavior are associated with economic development in low- and middle-income countries (LMICs). We aimed to assess the association between these two behaviors and country economic development among young adolescents in LMICs. Data came from the Global School-based Student Health Survey (GSHS) conducted between 2009 and 2016 in 68 LMICs. A total of 180,298 adolescents aged 12–15 years were included; 15.3% of young adolescents achieved the recommended level for sufficient physical activity (≥60 min/day of physical activity of any kind per week according to WHO) and 64.6% achieved a low sedentary behavior (≤2 h of sitting activities/day according to some guidelines, not accounting for sitting time at school or for doing homework). However, only 9.1% of young adolescents met the recommended levels of both behaviors. Comparing the lowest to the highest quintiles of a country’s purchasing power parity per capita (PPP), mean values of both physical activity (boys: 2.55 to 2.96 days/week; girls: 2.10 to 2.31 days/week) and sedentary behavior(boys: 1.86 to 3.13 h/day; girls: 1.83 to 3.53 h/day) increased. The prevalence of having both recommended behaviors decreased among boys (12.0% to 10.0%) and girls (9.6% to 4.9%) (p < 0.001). Although there might be an ecological fallacy, the findings emphasize the need for interventions to increase physical activity and reduce sedentary behavior among children and young adolescents.