Clinical evidence of exercise intervention in improving adults with type 2 diabetes mellitus and frailty: a narrative literature review

Background: The global aging process is accelerating with the increasing prevalence of diabetes mellitus in the elderly population. Frailty, a clinical syndrome closely related to age, is particularly prevalent in elderly with type 2 diabetes mellitus (T2DM). Previous studies indicated that some common mechanisms and exercise interventions may be an effective intervention for T2DM and frailty management. Objective: This narrative literature review aimed to provide evidence to explore possible common mechanisms and the role of exercise in management of T2DM combined with frailty. Methods: PubMed was searched for mechanistic studies. PubMed and China National Knowledge Infrastructure were searched for randomized controlled trials (RCTs) exploring exercise for T2DM and frailty. Results: Mechanistic analysis on 33 studies identified overlapping pathophysiological pathways between T2DM and frailty including encompassing inflammaging, insulin resistance, β-cell dysfunction, mitochondrial impairment, and gut dysbiosis. Evidence synthesized from 20 RCTs demonstrates that multicomponent exercise interventions could reduce frailty, lower blood glucose levels, and improve muscle strength for patients with T2DM and frailty, potentially by modulating these shared pathways, and resistance training enhances insulin sensitivity and muscle synthesis via GLUT-4 upregulation and Akt/mTOR activation. Conclusion: Multicomponent exercise and resistance training would be efficacy for elderly patients with T2DM and frailty through modulating the overlapping pathophysiological mechanisms.