Cumulative muscle strength and risk of diabetes: A prospective cohort study with mediation analysis

Previous studies assessing the association of muscle strength with risk of diabetes have seldomly accounted for the cumulative exposure over time. This study examined the association of 4-year cumulative muscle strength with risk of diabetes in middle-aged and older adults.We included participants without diabetes, who had 3 repeated measurements of muscle strength, which was assessed by grip strength (normalized by body-weight) and chair-rising time, over 4 years. Cumulative muscle strength was calculated based on trapezoid rule. Logistic regression analysis and mediation analysis for cumulative blood pressure were performed.We included 3731 and 3799 participants with data on cumulative grip strength and cumulative chair-rising time, respectively. The odds of diabetes were gradually reduced with increments in cumulative grip strength or decrements in cumulative chair-rising time, with the corresponding odds ratio being 0.79 and 0.89 per 1 standard deviation change after multivariable-adjustment. Cumulative systolic blood pressure mediated 10.8% and 14.2% of the associations of diabetes with cumulative grip strength and cumulative chair-rising time, respectively. Cumulative grip strength also correlated inversely with blood pressure, glycemia, and inflammation.Higher cumulative muscle strength was associated with lower risk of diabetes and better cardiometabolic health in middle-aged and older Chinese adults.