Prevalence and association of sleep duration and different intensities of physical activity with type 2 diabetes: The first evidence from CHARLS

Objectives: The aim of the current study was to examine the prevalence and the independent and joint association between sleep duration and different intensities of physical activity (PA) with type 2 diabetes (T2D) in the China Health and Retirement Longitudinal Study (CHARLS). Methods: We used data spanning all five years to evaluate the changes in T2D prevalence. Data from 2020 were used to examine the independent and joint associations between sleep duration and different intensities of PA with T2D. Sleep duration was classified into three categories: short (< 6 hours/day), normal (6 - 8 hours/day), and long (> 8 hours/day). PA levels were classified based on the IPAQ recommendations as follows: light-intensity PA (LPA, < 600 MET-minutes/week), moderate-intensity PA (MPA, 600- 3000 MET-minutes/week), and vigorous-intensity PA (VPA, > 3000 MET minutes/week). Results: The prevalence of T2D in the LPA and short sleep groups increased from 13.35 (95% CI = 10.41 - 16.75) and 11.52 (95% CI = 10.01 - 13.15) in 2011 to 17.27 ( 95% CI = 15.09 - 19.62) and 16.28 (95% CI = 15.34 - 17.25) in 2020, respectively ( p < 0.01). Compared with LPA, VPA was associated with lower odds of T2D (OR = 0.80, 95%CI = 0.68 - 0.95). Compared with normal sleep duration, short (OR = 1.19, 95%CI = 1.08 - 1.21) but not long sleep duration (OR = 1.02, 95%CI = 0.85 - 1.22) was more likely to have T2D. The odds of T2D were approximately 40% lower for individuals with LPA and normal sleep duration compared to those with LPA and short sleep duration (OR = 0.65, 95% CI = 0.46 - 0.91). In the MVP groups, combined with any sleep duration, the mitigation effect of exercise on T2D was observed (short: OR = 0.73, 95% CI = 0.56 - 0.95; normal: OR = 0.65, 95% CI = 0.51 - 0.8; long: OR = 0.63, 95% CI = 0.45 - 0.895). Conclusions: The current study highlights the high prevalence of T2D in the LPA and short sleep groups. Short sleep duration, rather than long sleep duration, was identified as a risk factor for T2D. VPA serve as a protective factor in reducing the high prevalence of T2D associated with sleep disorders.