The finger-ring test as an indicator of muscle mass estimated by dual-energy X-ray absorptiometry in an adult community-dwelling population.

Introduction: The finger-ring test (FRT) offers a simple method to screen older adults at increased risk of sarcopenia.

Objective: To investigate the association between the FRT and lean soft tissue mass estimated by dual-energy X-ray absorptiometry (DXA), and to further elucidate the FRT as an indicator of muscle mass, while accounting for potential confounders, in a community-dwelling population.

Materials and methods: Within this cross-sectional study 430 community-dwelling individuals aged 18 to 79 (286 women (66.5%) and 144 men (33.5%)) were enrolled. Data regarding FRT and anthropometric measurements were collected. Whole-body composition was estimated using DXA. Binary and ordinal logistic regressions were performed.

Results: The frequency of smaller calf, just fits, and bigger calf was 17.7%, 33.7%, and 48.6%, respectively. Regardless of sex, higher appendicular lean soft tissue mass adjusted for height squared was observed for higher FRT categories (p < 0.001). For the ordinal logistic regression model, each unity of increment in appendicular lean soft tissue mass adjusted for height squared (kg/m²) was associated with a higher probability of being allocated to higher finger-ring test categories, in both genders. A higher cumulative adjusted odds ratio was found for women (7.53; 95% confidence interval: 4.58-12.38) than for men (2.99; 2.00-4.48).

Conclusion: By demonstrating an association between the appendicular lean soft tissue mass estimated by DXA and the FRT, these results strengthen the utility of this simple self-test as an indicator of muscle mass, which can be used in the primary prevention of muscle mass decline and its recovery.