Study objectives: This study aims to explore the association between osteoporosis and nightly sleep duration among adult outpatients.
Design: This is a large-scale, retrospective cross-sectional study.
Setting: The setting was in a preventive medicine health center at a general community hospital in Tokyo, Japan.
Participants: There were 19,321 healthy individuals (≥50 years old) who underwent annual general health checkup between January and December 2008.
Measurements: The participants were divided into four groups according to their self-reported average nightly sleep duration (<6, 6-6.9, 7-7.9, and >8 h). Radial bone mineral density was measured using dual-energy X-ray absorptiometry, and T-score was compared to young adult mean to diagnose osteoporosis. Multivariate logistic regression was used to explore the association between sleep duration and osteoporosis.
Results: The mean age of the participants was 60.9 years (standard deviation [SD], 7.9) and 48.0% were female. The prevalence of osteoporosis was 8.0% (95% confidence interval [CI] = 7.6-8.4%). Those with sleep duration of >8 h were more likely to have osteoporosis (odds ratio [OR] = 1.35; 95% CI = 1.06-1.73) than those with short sleep duration (<6 h).
Conclusion: Those individuals with self-reported sleep duration of more than 8 h (long sleepers) appear to have higher odds of osteoporosis compared to the progressively shorter sleepers.