Might Thyroid Function in Patients with Turner Syndrome Have a Significant Impact on Their Muscle Strength?

TL;DR

This study explores how thyroid function affects muscle strength in women with Turner Syndrome, finding that thyroid hormone levels correlate with muscle strength.

Contribution

The study identifies a novel association between thyroid hormone levels and muscle strength in Turner Syndrome patients.

Findings

Higher TSH levels were positively correlated with muscle strength in Turner Syndrome patients.

Higher fT4 levels were negatively correlated with muscle strength in Turner Syndrome patients.

Autoimmune thyroid markers like aTPO and aTG may contribute to muscle deterioration in TS.

Abstract

Turner syndrome (TS) is a genetic disorder caused by abnormalities in one of the X chromosomes. Individuals with TS have a higher incidence of autoimmune thyroid disorders, particularly Hashimoto’s disease, leading to thyroid dysfunction, most commonly hypothyroidism. Hormonal imbalance, growth hormone deficiency, and reduced physical activity contribute to muscle weakness in TS patients, and thyroid dysfunction can exacerbate these effects. The purpose of this study was to evaluate whether thyroid factors affect muscle strength in female patients with TS. The study included 70 women with TS and 88 age- and weight-matched controls. TS diagnoses were genetically confirmed (mosaic karyotypes: n = 20; monosomy X: n = 37; structural abnormalities: n = 7). The main criterion for exclusion from the study was unbalanced thyroid function. Serum levels of thyroid-stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3), and thyroid antibodies (anti-thyroid peroxidase antibodies (aTPO), anti-thyroglobulin antibodies (aTG)) were measured, and muscle strength was assessed using hand-held dynamometry. In TS patients, higher TSH levels were positively correlated, and higher fT4 levels were negatively correlated with muscle strength. No such correlations were found in controls. Thyroid compensation may impact musculoskeletal health in TS. Lower-normal TSH levels are associated with reduced muscle strength, and autoimmune thyroid changes like aTPO and aTG may contribute to muscle deterioration. Further research is needed to confirm these findings.