Associations between thyroid hormones and appendicular skeletal muscle index, and hand grip strength in people with diabetes: The KAMOGAWA-A study

Abstract

Aim

To assess the effects of thyroid hormones on appendicular skeletal muscle index (SMI) and hand grip strength (HGS) in people with diabetes.

Methods

This cross-sectional cohort included 1,135 participants with diabetes admitted to 3 hospitals in Japan. Multiple regression analysis was performed to determine the associations among thyroid hormone levels, SMI, and HGS.

Results

Of the 1,135 participants, 480 were female. Their median (interquartile range) age, body mass index, durations of diabetes, and glycated haemoglobin levels were 68 years, 24.3 kg/m², 10 years, and 7.6 %, respectively. The median (interquartile range) SMI (kg/m²) and hand grip strength of the cohort were 7.1 kg/m² and 28.2 kg, respectively. Positive correlations between FT3 and the FT3/FT4 ratio with SMI and HGS was observed after adjusting for covariates in males. A negative correlation was found between the FT3/FT4 ratio and sarcopenia as a result of low SMI and low HGS in the male participants but not in females (p for interaction = 0.02).

Conclusions

FT3/FT4 ratios may impact skeletal muscles in people with diabetes—particularly in males. Assessments of FT3/FT4 ratios may represent key indicators of muscle mass and strength in males.