Favorable long-term effects of growth hormone replacement therapy on quality of life, bone metabolism, body composition and lipid levels in patients with adult-onset growth hormone deficiency

Abstract

Objective The goal of growth hormone (GH) replacement is to improve quality of life (QoL) and prevent the long-term complications of GH deficiency (GHD). Thirty-nine patients with adult-onset GH deficiency (AOGHD) who had originally participated in a randomized placebo-controlled crossover study involving treatment with either GH or placebo for nine months were enrolled in an open, 33-month follow-up study of the effects on QoL as well as bone and metabolic parameters. Methods GH replacement was dosed individually to obtain IGF-I concentrations that were within the upper part of the normal range for age (mean + 1SD). The variables were assessed on five occasions during the study. Results QoL, as assessed by the sum scores of HSCL-58, AGHDA, physical activity (KIMS question 11) and the dimension vitality in SF-36, improved. Markers of bone formation and resorption remained increased throughout the study period. Bone mineral area (BMA), bone mineral content (BMC) and bone mineral density (BMD) increased in both the lumbar (L2–L4) spine and total body. BMC and BMD increased in the femur. Hypogonadal women however, showed reduced bone mass during the study period. The changes in body fat mass (BFM) and lean body mass (LBM) were sustained throughout the long-term treatment (BFM −2.18 (+/−4.87) kg LBM by 2.01(+/−3.25) kg). Low-density lipoprotein cholesterol (LDL-C) levels were reduced by 0.6 (+/−1.1) mmol/l, and high-density lipoprotein cholesterol (HDL-C) levels increased by 0.2 (+/−0.3) mmol/l. No changes were observed in body weight, fasting total cholesterol, triglycerides, HbA1c and plasma glucose. Mean fasting insulin levels increased significantly from 110 pmol/l to 159 pmol/l, p < 0.02. Conclusion Long-term replacement of growth hormone in patients with AOGHD induces favorable effects on QoL as well as bone and metabolic parameters. An increase in insulin levels is also noteworthy.