Association of intrinsic capacity with incident type 2 diabetes mellitus in older Chinese: Guangzhou Biobank Cohort Study

Background: The World Health Organization introduced intrinsic capacity (IC) as a metric for healthy aging. However, we found no report on the association between IC and type 2 diabetes mellitus (T2DM). We investigated the association between IC and incident T2DM in older Chinese from the Guangzhou Biobank Cohort Study.

Methods: IC was assessed across five domains equally: locomotion, vitality, cognition, psychological and sensory. Composite IC scores (0-10) were classified into three groups: poor (0-5.9), fair (6.0-8.9), and high (9.0-10), with higher scores representing greater IC. Multivariable linear regression and cox regression was used to analyze the association between IC with glycemia and T2DM, respectively.

Results: Of 3582 participants with a mean age of 59.1 years (standard deviation (SD)=7.13) without baseline diabetes, during an average follow-up of 3.3 years (SD=0.86), 497 (13.87%) developed T2DM. After adjustments for potential confounders, those with baseline poor IC, versus high, had higher fasting glucose, 2-hour post-load glucose and glycosylated hemoglobin A_1c at follow-up, and a higher risk of incident T2DM (HR (95%CI): 1.80 (1.20, 2.72)). Among IC domains, only vitality impairment was associated with an increased risk of T2DM (P for trend < 0.001).

Conclusion: We first reported the prospective associations of poor IC and vitality with higher glycemia and incident T2DM risk. Enhancing muscle strength to improve functional ability may be a possible intervention for reducing future risk of T2DM in older populations.