Gender can modify the association between sleep duration, quality, and adiposity markers in elderly populations: Findings from the Neyshabur Longitudinal Study on Ageing (NeLSA)

Background: The global elderly population is rapidly expanding, and Iran is no exception to this demographic trend.Sleep disorders -as a common problem in the elderly -are associated with changes in body composition. However, limited studies have comprehensively examined the relationship between sleep parameters and detailed anthropometric indices in elderly populations. Aim: This study aimed to investigate the associations of sleep duration and quality with anthropometric indices in an elderly Iranian population. Methods: This cross-sectional study utilized data from the Neyshabur Longitudinal Study on Ageing (NeLSA), including 3,452 participants aged ≥60 years. Sleep duration and quality were assessed using the Pittsburgh Sleep Quality Index (PSQI). Anthropometric measurements included body fat mass (BFM), fat-free mass (FFM), visceral fat area (VFA), and waist-to-hip ratio (WHR). Multiple linear regression models were employed to examine associations, adjusting for demographic, socioeconomic, and health-related covariates. Results: Poor sleep quality was significantly associated with higher BFM (β=1.17, p=0.040), VFA (β=7.70, p=0.012), and WHR (β=0.0097, p=0.021) in women, but not in men. Short sleep duration (<7 hours) was unexpectedly associated with lower BFM (β=-1.29, p=0.023) and VFA (β=-6.54, p=0.034) in women. Conclusions: Sleep disturbances are highly prevalent among Iranian elderly. Poor sleep quality was specifically associated with adverse adiposity markers in women, while associations in men were absent. These findings underscore the necessity for gender-specific health strategies for healthy aging.