Effects of Acute Hypothyroidism on Body Composition in Differentiated Thyroid Cancer Patients Undergoing I-131 Therapy

This study investigated the short-term effects of acute hypothyroidism on body composition in patients with differentiated thyroid cancer undergoing I-131 whole-body scintigraphy. A total of 30 patients were evaluated using DEXA scans and biochemical tests both before and after a 3-week discontinuation of L-thyroxine. While thyroid-stimulating hormone levels rose significantly post-discontinuation, no statistically significant changes were observed in fat mass, muscle mass, bone content, or total body composition. However, notable increases were found in LDL, HDL, and total cholesterol levels. These findings suggest that short-term hypothyroidism induced for diagnostic purposes does not adversely affect body composition and may be considered safe in this patient group.