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

Aims: 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. Methods: 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. Results: 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. Conclusions: Higher cumulative muscle strength was associated with lower risk of diabetes and better cardiometabolic health in middle-aged and older Chinese adults.