Endocrine Abstracts

Context: Little is known of the importance of previous irradiation therapy for baseline characteristics and responsiveness to GH replacement in GH deficient (GHD) adults.

Objective/design/patients: In this prospective, single-centre, open-label study, the effects of 10-year GH replacement on metabolic variables and safety were determined in 18 GHD adults that had previously received pituitary irradiation therapy and 18 non-irradiated GHD patients. All patients had adult onset disease and complete deficiency of anterior pituitary hormones. Both groups were comparable in terms of gender, body mass index (BMI), and waist:hip ratio.

Results: At baseline, the GHD patients previously treated with pituitary irradiation therapy had higher serum levels of triglycerides (TG) and insulin and lower serum HDL-cholesterol level than non-irradiated patients (all P<0.05). The 10-year GH replacement improved serum lipid profile in both study groups, and in both groups variables reflecting glucose homeostasis responded similarly to GH replacement. At study end, serum HDL-cholesterol level was still lower in the GHD patients that had previously received pituitary irradiation therapy whereas serum TG and insulin levels were similar in both groups. During the 10-year GH replacement, four patients previously treated with pituitary irradiation therapy had cardiac events (two fatal) and one had a non-fatal cerebral infarction whereas only one non-fatal vascular event occurred in the non-irradiated patients.

Conclusions: GHD patients that have previously received pituitary irradiation therapy display a more severely impaired metabolic profile at baseline compared with non-irradiated patients. GH replacement can partly, but not fully, reverse these metabolic aberrations. This may be of importance for the more marked cardiovascular morbidity observed in this group.