Higher physical activity is independently associated with better sleep quality in older Iranian adults with type 2 diabetes

Sleep disorders are common among older adults with type 2 diabetes (T2DM) and negatively impact their quality of life. This study aimed to investigate the association between physical activity (PA) and sleep quality in Iranian older adults with T2DM. This cross-sectional study was conducted on a representative sample of 647 Iranian older adults (aged ≥ 60 years) with type 2 diabetes who participated in the Neyshabur Longitudinal Study on Ageing (NeLSA). The Persian versions of the Physical Activity Scale for the Elderly (PASE) and Pittsburgh Sleep Quality Index (PSQI) were utilized to measure the level of physical activity and sleep quality, respectively. A multiple linear regression model was performed to analyze the data and clarify the independent association of physical activity with sleep quality, adjusting for potential confounders including age, sex, education, marital status, income, and current job status. The mean age of participants was 67.5 ± 6.0 years, and 55.8% were female. The mean PASE and PSQI scores were 74.4 ± 70.8 and 6.9 ± 4.1, respectively. In the fully adjusted model using bootstrap regression with 1,000 replications (Model 4), a significant inverse association was found between physical activity and sleep quality (β = -0.0057, 95% CI: -0.0100 to -0.0014, p = 0.009), indicating that higher physical activity was associated with better sleep quality (lower PSQI scores). Furthermore, female gender (β = 1.85, 95% CI: 1.20 to 2.49, p < 0.001) and having financial difficulties (income status 3: β = 2.13, 95% CI: 1.13 to 3.13, p < 0.001) were significantly associated with poorer sleep quality (higher PSQI scores). Higher physical activity was independently associated with better sleep quality among Iranian older adults with type 2 diabetes, although the magnitude of the association was modest. Given the cross-sectional design, these findings do not establish causality.