[Clinical and muscular evaluation in patients with subclinical hypothyroidism]

Some symptoms and signs of hypothyroidism, as well as some laboratory abnormalities, may be present in subclinical hypothyroidism (SH). This study evaluates the prevalence of signs and symptoms of hypothyroidism and skeletal muscle dysfunction in 57 patients with SH compared to 37 euthyroid controls. The participants received a clinical score based on signs and symptoms of hypothyroidism. The muscle strength was estimated by manual testing and chair dynamometer and inspiratory force by manuvacuometer. Thyroid hormones and muscle enzymes were measured. The SH group presented with higher score (p< 0.01), complained about myalgia and weakness more frequently (p< 0.05), and showed strength disability in scapular and pelvic girdles (p< 0.05). The median free T4 serum levels were lower in SH (p< 0.001). These findings suggest that signs and symptoms of thyroid dysfunction may be related to lower levels of FT4 in SH and should be taken into account in the decision of beginning LT4 therapy.