Endocrine Abstracts

Growth hormone deficiency (GHD) has become increasingly recognized as a cause of metabolic syndrome, characterized by altered body composition and adverse cardiovascular risk. The effects of other pituitary hormone deficiencies or their replacement therapies on the metabolic profile in this clinical setting are still largely unclear. In this study, we aimed to evaluating the effects of replacement therapies of central hypoadrenalism and hypothyroidism on body composition in a cohort of 33 patients (F 7, M 26, median age: 51 years) with treated (10 cases) and untreated (23) GHD. Twenty-two patients had glucocorticoid deficiency, whereas central hypothyroidism was found in 25 subjects. All patients were on replacement therapy with hydrocortisone (median daily dose: 25 mg, range: 10–40) and/or levothyroxine (L-T4 median daily dose: 1.27 mcg/Kg, range: 0.4–2.6). Patients were evaluated for their body composition by DXA and anthropometric measures. Subjects with untreated GHD showed higher total body fat percentage (30.9% range: 22–52 vs. 23.0%, range: 11–42; P=0.03) and waist circumference (105 cm vs. 88 cm; P=0.009) as compared to patients with treated GHD. However, no significant differences in body composition were observed between patients with treated hypoadrenalism and those with preserved adrenal function (total body fat percentage: 30.6%, range 11–52 vs. 26.8, range 13–45; P=0.48; waist circumference: 98.5 cm, range 75–130 vs. 103.0 cm, range: 75–140; P=0.98) and between patients treated with L-T4 and those with normal thyroid function (total body fat percentage: 29.6%, range 11–52 vs. 30.4, range 13–45; P=0.82; waist circumference: 99.0 cm, range 75–130 vs. 98.0 cm, range: 75–140; P=0.91). Moreover, daily dose of hydrocortisone did not correlate with total body fat percentage (ρ: 0.01; P=0.9) and waist circumference (ρ: 0.29; P=0.27). Likewise, no significant associations were found between L-T4 daily dose and total body fat percentage (ρ: 0.17; P=0.4) and waist circumference (ρ: 0.25; P=0.30) in patients with central hypothyroidism. This study suggests GHD is the main determinant of body composition in adult GHD patients and replacement therapies with hydrocortisone and L-T4 do not seem to exert relevant effects on this clinical outcome.