Associations between health indicators and sleep duration of American adults: NHANES 2011-16.

BACKGROUND: This study aimed to investigate associations between health indicators and sleep duration in the general population. METHODS: This cross-sectional data from the National Health and Nutrition Examination Survey. Self-reported sleep duration was classified into short sleep (<7 h/day), regular sleep (7-8 h/day) and long sleep duration (>8 h/day). Health indicators included lifestyle indicators (smoking, alcohol use and physical inactivity), general health indicators (waist circumference and self-reported health condition) and chronic conditions [overweight/obesity, hypertension, diabetes, high cholesterol, chronic low back pain (CLBP) and oral health problems]. A series of multinomial logistic regression analysis were performed, controlling for confounders (age, sex, marital status, ethnic background, education level and poverty-to-income ratio). RESULTS: Data of 12 835 participants were analyzed. The mean (SD) age of participants was 50.0 (±17.4) years, and 50.6% were women. After adjusting for all health indicators, current smoking (OR: 1.37; 95% CI: 1.17-1.61), a poor (OR: 1.52; 95% CI: 1.23-1.88) health condition, CLBP (OR: 1.40; 95% CI: 1.16-1.69) and oral health problems (OR: 1.28; 95% CI: 1.10-1.49) were associated with short sleep duration. No independent association with long sleep duration was observed in this study. CONCLUSIONS: The results confirm that lifestyle indicators (current smoking and physical inactivity), general health indicators (self-reported health condition) and presence of some chronic conditions (CLBP and oral health problems) are associated with short sleep duration. The results did not confirm that any health indicator was associated with long sleep duration.

Vitamin B12, homocysteine and depressive symptoms: a longitudinal study among older adults.

BACKGROUND/OBJECTIVES: The roles of vitamin B12 and homocysteine concentration in depression are not clear. We investigated cross-sectional and prospective associations of serum vitamin B12 and plasma homocysteine with depressive symptoms in Dutch older adults. SUBJECTS/METHODS: In the Longitudinal Aging Study Amsterdam (LASA), blood was collected in 1995/1996 among 1352 men and women aged ⩾65 years. Depressive symptoms were assessed with the Center for Epidemiologic Studies Depression Scale (CES-D) six times from 1995/1996 to 2011/2012. Multiple linear regression and mixed models were used to assess whether vitamin B12 and homocysteine were associated with severity at baseline and course of depressive symptoms over 16 years. Cox regression analyses were performed for the associations with incidence of depression (CES-D ⩾16 and/or antidepressant use). All analyses were adjusted for sociodemographic characteristics and lifestyle factors. RESULTS: Vitamin B12 was neither cross-sectionally (n=1205) nor prospectively (n=1012) associated with depressive symptoms (adjusted ß for CES-D over time, lowest versus highest quartile: -0.04 (95% confidence interval (CI): -0.15-0.06)). We also found no association with incident depression (n=853), except for a higher risk of depression over time in younger participants (aged 64.8-73.4 years; continuous vitamin B12, adjusted hazard ratio per s.d.: 1.38 (95% CI: 1.10-1.72)). For homocysteine, no associations were found, except for a lower risk of depression in younger participants. CONCLUSIONS: Our study did not confirm earlier shown associations of serum vitamin B12 and plasma homocysteine with severity and course of depressive symptoms and incidence of depression in older adults. Further research into the influence of homocysteine metabolism on mental health is needed.