To evaluate the validity and the reliability of the Oura Ring Generation 3 (Gen3) with Oura Sleep Staging Algorithm 2.0 (OSSA 2.0) through multi-night polysomnography (PSG). Participants were 96 generally healthy Japanese men and women aged between 20 and 70 years contributing with 421,045 30-s epochs. Sleep scoring was performed according to American Academy of Sleep Medicine criteria. Each participant could contribute with a maximum of three polysomnography (PSG) nights. Within-participant means were created for each sleep measure and paired t-tests were used to compare equivalent measures obtained from the PSG and Oura Rings (non-dominant and dominant hand). Agreement between sleep measures were assessed using Bland-Altman plots. Interrater reliability for epoch accuracy was determined by prevalence-adjusted and bias-adjusted kappa (PABAK). The Oura Ring did not significantly differ from PSG for the measures time in bed, total sleep time, sleep onset latency, sleep period time, wake after sleep onset, time spent in light sleep, and time spent in deep sleep. Oura Rings worn on the non-dominant- and dominant-hand underestimated sleep efficiency by 1.1 %-1.5 % and time spent in REM sleep by 4.1-5.6 min. The Oura Ring had a sensitivity of 94.4 %-94.5 %, specificity of 73.0 %-74.6 %, a predictive value for sleep of 95.9 %-96.1 %, a predictive value for wake of 66.6 %-67.0 %, and accuracy of 91.7 %-91.8 %. PABAK was 0.83-0.84 and reliability was 94.8 %. Sleep staging accuracy ranged between 75.5 % (light sleep) and 90.6 % (REM sleep). The Oura Ring Gen3 with OSSA 2.0 shows good agreement with PSG for global sleep measures and time spent in light and deep sleep.

A third of dementia cases could be attributable to modifiable risk-factors. Midlife high-density lipoprotein cholesterol (HDL-C) is a measure which could help identify individuals at reduced risk of developing age-related cognitive decline. The Japan Public Health Centre-based prospective (JPHC) Study is a large population-based cohort which started in 1990. This study included 1299 participants from Saku area in Nagano prefecture. Participants had HDL-C measured in 1995–1996, and underwent a mental health screening in 2014–2015. Of these, 1114 participants were included in MCI analyses, and 781 participants were included in dementia analyses. Logistic regression models were used to determine odds ratios (OR) and 95% confidence intervals (CI) for the association between HDL-C quartiles and MCI and dementia, respectively. For dementia analysis, quartiles 2–4 were collapsed due to low number of cases. Missing data was addressed through multiple imputations. There were 386 cases of MCI and 53 cases of dementia. Compared to the lowest HDL-C quartile, the highest HDL-C quartile was significantly inversely associated with MCI (OR = 0.47, 95% CI, 0.28–0.79) in the multivariable analysis. High HDL-C (quartiles 2–4) was inversely associated with dementia compared to low HDL-C (quartile 1) (OR = 0.37, 95% CI, 0.16–0.88). This study has found that high midlife HDL-C levels are inversely associated with both late-life MCI and dementia in a Japanese population.

Coping strategies may be significantly associated with health outcomes. This is the first study to investigate the association between baseline coping strategies and cardiovascular disease (CVD) incidence and mortality in a general population cohort. The Japan Public Health Center-based prospective Study asked questions on coping in its third follow-up survey (2000–04). Analyses on CVD incidence and mortality included 57 017 subjects aged 50–79 without a history of CVD and who provided complete answers on approach- and avoidance-oriented coping behaviours and strategies. Cox regression models, adjusted for confounders, were used to determine hazard ratios (HRs) according to coping style. Mean follow-up time was 7.9 years for incidence and 8.0 years for mortality. The premorbid use of an approach-oriented coping strategy was inversely associated with incidence of stroke (HR = 0.85; 95% CI, 0.73–1.00) and CVD mortality (HR = 0.74; 95% CI, 0.55–0.99). Stroke subtype analyses revealed an inverse association between the approach-oriented coping strategy and incidence of ischaemic stroke (HR = 0.79; 95% CI, 0.64–0.98) and a positive association between the combined coping strategy and incidence of intra-parenchymal haemorrhage (HR = 2.03; 95% CI, 1.01–4.10). Utilizing an avoidance coping strategy was associated with increased mortality from ischaemic heart disease (IHD) only in hypertensive individuals (HR = 3.46; 95% CI, 1.07–11.18). The coping behaviours fantasizing and positive reappraisal were associated with increased risk of CVD incidence (HR = 1.24; 95% CI, 1.03–1.50) and reduced risk of IHD mortality (HR = 0.63; 95% CI, 0.40–0.99), respectively. An approach-oriented coping strategy, i.e. proactively dealing with sources of stress, may be associated with significantly reduced stroke incidence and CVD mortality in a Japanese population-based cohort.

Objectives: Despite accumulating research on yoga and its positive impact on both physiological and psychological health, it is still unclearhowyoga improves health. Two central components of yoga,yogic breathingandmindfulness, may be important mechanisms by which individuals learn to cope with their daily stressors, and thereby reduce their risk of developing stress-related illness. In this study, we experimentally tested whether yogic breathing as a stress coping mechanism and increased mindfulness mediates the psychological health benefits of a yoga interventionMethods: Seventy-one middle-aged adults (78% women;M_age53.5 ± 6.9) who self-rated as moderately stressed were randomly assigned to either a control group or a 5-week yoga intervention called the Yoga and Mindfulness Intervention (YOMI) program. The YOMI combines 60 min of yin yoga practice with 30 min of psychoeducation, administered twice weekly; participants also completed a 5-min breathing exercise as homework daily.Results: The YOMI group showed greater reductions in anxiety, depression, and sleep problems compared with controls (R²varied between .09 to .23), and these reductions were statistically mediated by increased use of yogic breathing and a related increase in participants’ overall mindfulness.Conclusions: These mediation results provide new insights into how yoga improves psychological health and suggests promising implications for policymakers aimed at improving public health.