Baseline characteristics and the effects of two years of growth hormone replacement therapy in adults with growth hormone deficiency previously treated for Cushing's disease

OBJECTIVE To determine baseline characteristics and the effects of 2 years of GH replacement therapy on body composition, muscle strength, bone mass, and metabolic indices in GH-deficient (GHD) adults previously treated for pituitary-dependent Cushing's disease. PATIENTS A single-centre, open-labelled, prospective study. PATIENTS Fifteen consecutive GHD adults previously treated for pituitary-dependent Cushing's disease (CD group) and 15 closely matched GHD adults with previous nonfunctioning hypopituitary disease (NF group) were included. All patients had adult-onset GH deficiency. RESULTS The mean dose of GH was similar in both study groups during the 2-year treatment. At baseline, diastolic blood pressure was higher, and lumbar (L2-L4) bone mineral density (BMD) was lower, in the CD group than in the NF group. The increase in lean mass in response to GH therapy, as measured by dual-energy X-ray absorptiometry (DEXA), was less marked in the CD group. GH replacement therapy reduced diastolic blood pressure only in the CD group. The patients in the CD group had greater treatment response in lumbar (L2-L4) spine BMD and in isometric and isokinetic knee extension strength than the patients in the NF group. At study end, no difference remained between the two study groups. CONCLUSIONS This study revealed differences in the baseline characteristics between GHD patients previously treated for Cushing's disease as compared with closely matched GHD patients with previous nonfunctioning hypopituitary disease. The 2-year GH replacement therapy eliminated all the differences between the two study groups.