Metformin in Elderly Patients With Type 2 Diabetes and Muscle Strength, Muscle Mass, and Physical Function: Positive or Negative Correlation?

With the accelerating aging process in China, sarcopenia has drawn increasing attention. Sarcopenia is an age-related geriatric syndrome characterized by reductions in muscle mass, muscle strength, and/or physical function. Sarcopenia has a high prevalence, often insidious onset, and broad impacts on physiological functions. According to the 2019 report from the Asian Working Group for Sarcopenia (AWGS), sarcopenia prevalence among elderly Asians ranged from 5.5% to 25.7%, with males exhibiting higher rates (5.1% to 21.0%) than females (4.1% to 16.3%). Particularly among patients with diabetes, sarcopenia incidence was significantly elevated, with a prevalence of 14.8% reported in Chinese diabetic populations. Sarcopenia exerts numerous adverse effects. Sarcopenia is strongly associated with adverse cardiovascular events and increased mortality. Sarcopenia is linked to cancer and significantly elevates the risk of various postoperative complications in patients with gastrointestinal malignancies, including dysphagia, cognitive impairment, fractures, falls, hospitalization, and all-cause mortality. Sarcopenia and diabetes frequently coexist within the same individual, leading to multiple adverse outcomes. Sarcopenia results in declining in function flexibility and responsiveness in diabetic patients, causing gait alterations and impaired balance, limiting daily activities, and is closely linked to risks of falls, fractures, depression, frailty, and mortality. Thus, it is critically important to treat sarcopenia alongside diabetes and avoid detrimental effects of hypoglycemic drugs on muscle. Metformin lowers blood glucose by increasing muscle glucose uptake, inhibiting hepatic glucose output and gluconeogenesis, and promoting glucose excretion into the intestinal lumen; it also reduces the risk of diabetic cardiovascular disease, diabetic retinopathy, nephropathy, and neuropathy. There remains controversy in current studies regarding metformin's impact on sarcopen