Recombinant human growth hormone (rhGH) replacement is advocated in adult growth hormone-deficient (GHD) patients to increase bone mass and improve lipid profile, body composition, and quality of life. The long-term effects of discontinuation of rhGh replacement are unknown.
This cohort study and systematic review aim to evaluate the long-term metabolic effects of discontinuation of rhGh replacement in adult GHD patients, with a subgroup analyses according to age (< or > 60 years). Data on anthropometry, lipids, glucose, and bone mass density (BMD) were assessed for 3 years after discontinuation.
Cohort study included 64 patients who had discontinued rhGh replacement for >12 months. Fat percentage increased from 31.5±9.5% to 33.8±9.0% (mean difference 2.3, P=0.003). BMI decreased only in subjects <60 years (P=0.014). Glucose, total cholesterol, and LDL-cholesterol levels did not change; however, the percentage of patients on statins increased slightly from 39% to 44%. HDL-C concentration increased only in patients <60 years (mean difference 0.2, P=0.043). Lumbar spine BMD did not change; however, femoral neck BMD and bone turnover markers decreased in subjects <60 years (P=0.001). Systematic review included eight studies (n=166 patients) with a follow-up duration of 6–18 months. Of the eight studies, three qualified as low risk of bias and five as having an intermediate risk of bias. None of the studies reported handling of statins, bisphosphonates, and glucose-lowering medication or excluded patients using these medications.
In this study, discontinuation of rhGh replacement resulted in metabolic changes only in patients <60 years after 3 years. Further research warrants to determine the optimal strategies for (dis)continuation of rhGh replacement in adult patients with GHD.