Author(s): GRECO, F., LISTA, M.1, DI LUIGI, L.1, BRUNETTI, A.2, AVERSA, A.2, SGRÒ, P.1, Institution: UNIVERSITY OF ROME 'FORO ITALICO', Country: ITALY, Abstract-ID: 588

INTRODUCTION:
Thyroid hormones levels are closely correlated with changes in body mass index and body composition regardless of the presence of thyroid dysfunctions [1, 2]. Instead, little is known regarding the influence of thyroid hormones on muscular fitness components [3]. A preserved skeletal muscle mass and strength within a framework of excess body mass may directly influence thyroid function in individuals affected by obesity [4,5]. However, this association may differ between males and females. Therefore, this study aimed to investigate the association between thyroid hormone levels and muscular indexes in male and female adults affected by obesity.
METHODS:
A total of 105 individuals with obesity (65 females, 40 males) in euthyroidism have been recruited. The median age for both groups was 44.0 [28.5] years and the median BMI of 33.5 [8.0] kg/m2. Muscular indexes of interest were grip strength - evaluated on the dominant hand using the handgrip test (HG) and muscle performance – conducted on the lower body with the 10-repetition chair-stand test (CST). Free-triiodothyronine (FT3), free-thyroxine (FT4) and their ratio (FT3/FT4) were evaluated to assess thyroid function.
RESULTS:
Pearson correlation analysis showed a positive association between HG and FT3 (r=0.261, p=0.036) and a negative association between FT3/FT4 and CST (r= - 0.266, p=0.032) in females. No correlations in males were found (p> 0.05).
CONCLUSION:
Levels of FT3 and FT3/FT4 ratio in euthyroidism state may influence muscular indexes only in females affected by obesity. More research is needed to understand the mechanisms behind this correlation and whether thyroid hormones could be a potential biomarker for muscle-related parameters.
References:
1. Walczak and Sieminska, Int J Environ Res Public Health 2021.
2. Ruiz et al. Eur J Endocrinol. 2022.
3. Greco et al. Int Journal of Sport Medicine. 2023.
4. Zupo et al. Front Endocrinol (Lausanne). 2020.
5. Lee et al. Int J Endocrinol. 2020