The effect of growth hormone (GH) replacement on blood glucose homeostasis in adult nondiabetic patients with GH deficiency: real‐life data from the NordiNet® International Outcome Study

Summary Objective To assess the effect of 4 years’ growth hormone ( GH ) replacement on glucose homeostasis and evaluate factors affecting glycosylated haemoglobin (HbA 1c ) in adults with growth hormone deficiency ( GHD ). Design NordiNet ® International Outcome Study, a noninterventional study, monitors long‐term effectiveness and safety of GH replacement [Norditropin ® (somatropin), Novo Nordisk A/S] in real‐life clinical practice. Patients Nondiabetic patients ( n = 245) with adult‐onset GHD (age ≥20 years at GH start), ≥4 years’ GH replacement and HbA 1c values at baseline and 4 years were included in the analysis. Measurements Changes from baseline (∆) to 4 years in HbA 1c , fasting plasma glucose ( FPG ), IGF ‐I, lipids (high‐density lipoprotein cholesterol, low‐density lipoprotein cholesterol, total cholesterol, triglycerides), waist circumference, glycaemic (HbA 1c <5·7%; HbA 1c , 5·7–6·5%; HbA 1c , ≥6·5%) and metabolic health status were evaluated. Effects of baseline HbA 1c , gender, baseline age, average GH dose and baseline body mass index ( BMI ) on ΔHbA 1c were investigated. The models were adjusted for concomitant medication use. Results Mean (standard deviation) baseline HbA 1c was 5·13 (0·65)% and remained at the same level at 4 years. Age at treatment start ( P = 0·0094) and BMI ( P = 0·0008) had a significant impact on ∆HbA 1c . At 4 years, 85% of patients with HbA 1c <5·7% (normal levels) at baseline and 55% of patients with HbA 1c 5·7–6·5% (impaired glucose tolerance) at baseline remained in the same glycaemic health category. Nineteen patients improved from impaired glucose tolerance to normal HbA 1c . Seven patients developed diabetes. Conclusions These data demonstrate that 4 years’ GH replacement therapy did not adversely affect glucose homeostasis in the majority of adults with GHD .