Associations Between Sleep Duration, Daytime Nap Duration, and Osteoporosis Vary by Sex, Menopause, and Sleep Quality

Context: Associations between sleep, daytime nap duration, and osteoporosis remain uncertain, and far less is even known about the influence of sex, menopause, and sleep quality on them. Objective: The objective of the study was to test the associations between sleep, daytime nap duration, and osteoporosis and whether they vary by sex, menopause, and sleep quality. Design, Setting, and Patients: This cross-sectional study was based on two communities in China. A total of 8688 participants (3950 males and 4738 females) aged 40 years or older were enrolled in the study. Main Outcomes Measures: Self-reported sleep duration, daytime nap duration, sleep quality, and calcaneus bone mineral density were recorded. Results: Sleep duration of 8-9 h/d and nap duration of 0 min/d were regarded as reference values. In postmenopausal women, risks (odds ratio and 95% confidence interval) of osteoporosis for sleep durations of 7-8 h/d, 9-10 h/d, and 10 h/d or longer were 1.531 (1.106, 2.121), 1.360 (1.035, 1.787), and 1.569 (1.146, 2.149), respectively (P < .05), and risks of osteoporosis for daytime nap durations of 30-60 min/d and longer than 60 min/d were 1.553 (1.212-1.989) and 1.645 (1.250-2.165), respectively (P < .05). However, a significant difference was not consistently observed in men or premenopausal women, regardless of sleep or daytime nap duration. As for sleep quality, positive results were seen most remarkably in postmenopausal females with good sleep. Conclusions: Sleep durations of 7-8 h/d, 9-10 h/d, and 10 h/d or longer, as well as longer daytime napping times, tend to present higher risks of having osteoporosis, and this tendency is most obvious in postmenopausal women reporting good-quality sleep.