# The bidirectional relationship between diabetes and poor muscle function in older adults: data from two population-based studies

## TL;DR

This study shows that diabetes and poor muscle strength in older adults are linked in both directions, with diabetes worsening muscle strength and weaker muscles increasing diabetes risk.

## Contribution

The study reveals a bidirectional relationship between diabetes and muscle strength decline in older adults using population-based data.

## Key findings

- Diabetes is associated with a faster decline in muscle strength compared to non-diabetic individuals.
- Lower muscle strength is linked to a higher risk of developing diabetes in older adults.

## Abstract

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.