Association of Daytime Napping and Diagnosed Diabetes in Middle-Aged Premenopausal, Middle-Aged Postmenopausal, and Older Postmenopausal Chinese Women

Purpose: To examine associations of daytime napping and diagnosed diabetes in middle-aged premenopausal, middle-aged postmenopausal, and older postmenopausal Chinese women. Design: Quantitative, cross-sectional. Setting: 2015 cross-sectional data from China Health and Retirement Longitudinal Study. Participants were recruited from 150 counties/districts and 450 villages/resident committees. Participants: Six thousand nine hundred and forty women aged 45 years and older (mean age = 61 years) stratified by age and menopausal status. Measures: The outcome was self-reported diagnosed diabetes. The exposure was self-reported daytime napping (0, >0-<= 60, or >60 min/d). Participants were stratified to middle-aged premenopausal, middle-aged postmenopausal, and older postmenopausal women according to their age (<= 60 or >60 years) and menopausal status. Analysis: One-way analysis of variance and chi(2) tests were conducted to explore differences on characteristics of middle-aged premenopausal, middle-aged postmenopausal, and older postmenopausal women. Multiple logistic regressions were used to estimate adjusted odds ratios (ORs) for diagnosed diabetes according to daytime napping in the total sample, middle-aged premenopausal, middle-aged postmenopausal, and older postmenopausal Chinese women. Results: Participants' mean self-reported daytime napping duration was 34 minutes. Women who napped more than 60 minutes were more likely to report diagnosed diabetes (OR = 1.39, 95% confidence interval (CI), 1.09-1.76) comparing to those who did not nap, after adjusting for potential confounders. No statistical significance of interaction term between daytime napping and age/menopausal status was detected (P = .602 and P = .558) among total women. The stratified analysis revealed the significant association among middle-aged postmenopausal women napping more than 60 minutes (OR = 1.81, 95% CI, 1.18-2.77). The association, however, was found to be insignificant in middle-aged premenopausal women and older postmenopausal women. Conclusions: Long daytime nap (>60 min/d) was associated with diagnosed diabetes in middle-aged postmenopausal women in China.