Correction: Determination of specific life changes on psychological distress during the COVID-19 pandemic.

[This corrects the article DOI: 10.1371/journal.pone.0256481.].

Low plasma 25-hydroxyvitamin D levels are not associated with a high risk of recurrent falls in community-dwelling Japanese adults: the Murakami cohort study.

Reports on the association between vitamin D levels and fall risk have been mixed, and long-term follow-up studies are lacking. This 5-year cohort study of 5,343 community-dwelling Japanese people aged 40-74 years found that low vitamin D levels are not associated with a high risk of recurrent falls. PURPOSE: Findings of cohort studies on the association between plasma 25-hydoxyvitamin D (25[OH]D) levels and fall risk have been mixed, and long-term follow-up studies are lacking. The present study investigated whether low plasma 25(OH)D levels are longitudinally associated with a high risk of recurrent falls in adults. METHODS: This 5-year cohort study included 5,343 community-dwelling Japanese people aged 40-74 years. Baseline blood collection and a questionnaire survey were conducted in 2011-2013. Plasma 25(OH)D levels were determined and divided into quintiles after stratification by season, sex, and age group. Information on recurrent falls occurring in the year before the survey 5 years later was obtained, and participants with two or more falls were considered to have experienced recurrent falls. Covariates were sex, age, marital status, education, occupation, BMI, total physical activity levels, calcium intake, vitamin K intake, smoking, drinking, and disease history. RESULTS: Mean age and 25(OH)D levels were 60.9 years and 50.9 nmol/L, respectively. In the follow-up survey, 209 recurrent falls were reported. Plasma 25(OH)D levels were not significantly associated with the occurrence of recurrent falls in men, women, or men/women-combined (adjusted P for trend = 0.1198, 0.8383, and 0.2355, respectively). In men and men/women-combined, adjusted ORs for recurrent falls in the lowest quintile were significantly lower (adjusted OR = 0.42 and 0.59, respectively) than the middle quintile (reference). CONCLUSION: Low plasma 25(OH)D levels are not associated with a high risk of recurrent falls in middle-aged and older people. Further longitudinal studies will be needed to confirm our findings in other populations.

Self-Reported Sleep Duration and Bedtime Are Associated with Dementia Risk in Community-Dwelling People Aged 40-74 Years: The Murakami Cohort Study.

Background: Sleep is a potentially modifiable factor associated with dementia, including Alzheimer's disease, but current evidence supporting this is insufficient. Objective: This study aimed to determine whether sleep duration and bedtime patterns are associated with the risk of dementia among middle-aged and older people. Methods: This cohort study had an eight-year follow-up period. Participants were 13,601 community-dwelling people aged 40-74 years living in Murakami (Niigata, Japan). Data were collected using a self-administered questionnaire. Predictors were self-reported sleep duration and bedtime, and the outcome was newly-diagnosed dementia determined using the long-term care insurance database. Covariates were demographic characteristics, body mass index, smoking, alcohol consumption, total physical activity, insomnia symptoms, disease history, and either bedtime or sleep duration. Cox proportional hazard models were used to calculate hazard ratios (HRs). Results: The mean age of participants at baseline was 59.2 years. Over a mean follow-up period of 8.0 years, 319 cases of dementia were observed. A long self-reported sleep duration relative to the reference sleep duration (7 hours) was associated with increased dementia risk, with the "8 hours" group (adjusted HR = 1.30, 95% CI:0.99-1.73) and "≥9 hours" group (adjusted HR = 1.46, 95% CI:1.00-2.15) having an increased risk (marginally significant) relative to the reference group. Early bedtime was associated with increased dementia risk (adjusted p for trend = 0.0010), with the "21 : 00 or earlier" group (adjusted HR = 1.61, 95% CI:1.14-2.28) having an increased risk relative to the reference ("23 : 00"). Conclusions: A long self-reported sleep duration and early bedtime are both associated with increased dementia risk in middle-aged and older people.

Body mass index, height, and osteoporotic fracture risk in community-dwelling Japanese people aged 40-74 years.

INTRODUCTION: The association between body size and fracture risk is complex and varies by sex and ethnicity. This study aimed to examine associations of body mass index (BMI) and height with osteoporotic fracture risk in middle-aged and older people. MATERIALS AND METHODS: This 10-year cohort study included 13,151 community-dwelling Japanese people aged 40-74 years. A self-administered questionnaire survey was conducted at baseline to obtain information on demographic characteristics, body size, lifestyle, and disease history. BMI (kg/m2) was categorized as underweight (< 18.5), low-normal (18.5-21.7), high-normal (21.8-24.9), overweight (25.0-29.9), and obese (≥ 30.0). Height was categorized into quartiles. All incident cases of major osteoporotic fractures, including fractures of the distal radius, neck of the humerus, neck or trochanter of the femur, and vertebrae, were obtained from medical records during follow-up. RESULTS: Mean participant age was 58.8 years. In men, the underweight group had a significantly higher hazard ratio (HR) for total fracture (adjusted HR = 2.46), and the obese group had significantly higher HRs for total (adjusted HR = 3.01) and vertebral (HR = 3.77) fractures relative to the reference (overweight) group. No significant associations were observed between BMI and risk of any fracture in women. Higher quartiles of height were associated with higher vertebral fracture risk (adjusted P for trend = 0.023) only in women. CONCLUSION: BMI and osteoporotic fracture risk showed a U-shaped association in men, whereas higher height was associated with higher vertebral fracture risk in women, suggesting sex-dependent differences in these associations.