The bidirectional relationship between diabetes and poor muscle function in older adults: data from two...

Skeletal muscle dysfunction contributes significantly to disability, which is one of the most common complications of diabetes in older adults. We aimed to assess whether diabetes was associated with a steeper muscle strength decline and whether lower strength is related to a higher diabetes incidence in older adults.

A prospective analysis of data from two Italian population-based studies in older adults (the Invecchiare in Chianti and Progetto Veneto Anziani studies). Diabetes was assessed at baseline and after a median of 4.4 (first follow-up) and 6.3 years (second follow-up) using multiple sources of information. Muscle function was assessed as handgrip strength.

The sample comprised 3927 participants (58.6% females) with a mean age of 75.5 years (29.6% aged ≥80 years). After adjusting for potential confounders, the decline in muscle strength among individuals with diabetes exceeded that of those without diabetes by 0.70 kg (95% CI, -1.30 to -0.11) at the first follow-up and by 0.84 kg (95% CI, -1.61 to -0.07) at the second follow-up. In those taking oral antidiabetics, this association was even stronger. Over a median 5-year follow-up, 186 incident diabetes cases were recorded. In a multivariable Cox regression, each 1-SD higher in the handgrip/body weight ratio was associated with an 20% lower likelihood of incident diabetes (95% CI, 0.68-0.95, n = 3102).

These findings demonstrate an independent circular relationship between diabetes and skeletal muscle strength. In older people, muscle dysfunction may be a long-term diabetes complication. Whether increasing muscle strength might reduce diabetes risk remains to be determined.