Changes in body composition in adult patients with hypopituitarism after substitutive treatment with growth hormone

BACKGROUND: Adult growth hormone (GH) deficiency is associated with changes in body composition, with lower total body water (TBW) and fat free mass (FFM) and higher fat mass (FM). These changes can be modified after sustitutive treatment with GH. PATIENTS AND METHODS: We studied 20 patients, 14 males and 6 females with hypopituitarism and GH deficiency, the mean age was 40.3 years, as well as 20 comparable controls. The diagnosis of GH deficiency was based on the lack of GH response after an hypoglycemic test. We determined body composition by bioelectrical impedance. An initial 6 month double-blind placebo controlled phase was followed by an open treatment phase ending when the patients had received GH for 18 or 24 months. The initial dose was 0.125 U/kg/week during the first month and after 0.25 U/kg/week. RESULTS: The patients showed lower TWB and FFM and higher BF in relation to controls and after 3 months of GH treatment an increase of the TBW, FFM and a decrease in BF and waist/hip ratio was observed with a steady state in the changes of body composition after 3 months that continued 6 months after the GH treatment withdraw. Two patients presented maleolar oedema, 4 arterial hypertension that was settled with GH dose reduction and in the fourth patient the treatment had to be withdraw, Three patients presented carpal tunnel syndrome. In 4 patients the treatment was withdrawn. CONCLUSIONS: In patients with adult GH deficiency, we can observe differences in the body composition that can be significantly modified by GH treatment.