SummaryBased on the use of Osteoporosis Self-Assessment Tool for Asians (OSTA) to assess osteoporosis risk, we found that short sleep duration and taking a daytime nap had an increased risk of osteoporosis.PurposeTo explore the associations between different sleep patterns with osteoporosis.Methods3659 postmenopausal women (average age of 60 years) were divided into low, middle, and high osteoporosis risk categories based on the Osteoporosis Self-Assessment Tool for Asians (OSTA). After having collected by a standard questionnaire, total and nocturnal sleep duration was collapsed to form categories of ≤ 6 h, > 6 h and ≤ 7 h, > 7 h and ≤ 8 h, > 8 h and ≤ 9 h, > 9 h, and daytime nap duration of 0 h and > 0 h.ResultsAs a categorical variable, the total sleep duration of ≤ 6 h per day (OR = 1.34, 95% CI 1.04–1.72), nocturnal sleep duration of ≤ 6 h per night (OR = 1.65, 95% CI 1.24–2.18), and taking a daytime nap (OR = 1.33, 95% CI 1.09–1.64) had higher osteoporosis risk after adjustment for covariates. As a continuous variable, after the adjustment for covariates, both longer total (OR = 0.86, 95% CI 0.78–0.94) and nocturnal sleep duration (OR = 0.83, 95% CI 0.76–0.91) had lower risk of osteoporosis risk while taking longer daytime nap (OR = 1.10, 95% CI 1.02–1.19) had higher osteoporosis risk.ConclusionsPostmenopausal women with both short total and nocturnal sleep duration (6 h or less) and taking a daytime nap had increased osteoporosis risk as assessed by OSTA.