Context: The effects of GH replacement in elderly GH deficient (GHD) adults are not well known.

Objective/Design/Patients: In this prospective, single-center, open-label study, baseline characteristics and the effects of 2-year GH replacement were determined in 24 GHD adults above 65 yr of age and in 24 younger GHD patients (mean age 37; range 27-46 yr). All patients had adult onset disease and both groups were comparable in terms of number of pituitary hormonal deficiencies, gender, body mass index (BMI), and waist:hip ratio. Duration of hypopituitarism was, however, longer in the elderly patients.

Results: The mean maintenance dose of GH was 0.31 (SEM 0.03) mg/day in the elderly GHD patients and 0.44 (0.04) mg/day in the younger patients. The less marked response in IGF-I SD score, total body fat and extracellular water in the elderly patients lost significance when the dose of GH were accounted for in the statistical analyses. In spite of the lower dose in the elderly GHD group, these patients had a more marked reduction in waist:hip ratio and serum low density lipoprotein-cholesterol (LDL-C) level, and these differences remained also after correction for duration of hypopituitarism. There was no difference at baseline or in responsiveness in lean mass, bone mineral density and glucose homeostasis.

Conclusions: This study identifies elderly GHD adults as a GH sensitive group in whom a low dose of GH can improve body composition and serum lipid profile without any significant impairment of glucose metabolism. GH replacement should therefore be considered in elderly GHD adults.