Endocrine Abstracts

Objective: Few studies have determined the effects of more than 5-10 years of GH replacement in adults on body composition and metabolic parameters.

Design/Patients: In this prospective, single-center, open-label study, the effects of 15 years of GH replacement on body composition and metabolic parameters were determined in 156 hypopituitary adults (93 men) with adult onset GH deficiency (GHD). Mean age was 50.5 (range 22–74) years at study start. Body composition was measured using dual-energy X-ray absorptiometry (DXA).

Results: The mean initial GH dose of 0.55 (SEM 0.03) mg/day was gradually lowered to 0.40 (0.01) mg/day after 15 years. The mean serum insulin-like growth factor 1 (IGF1) SDS increased from −1.53 (0.10) at baseline to 0.74 (0.13) at study end (P<0.001 vs baseline). Body mass index (BMI) increased from 27.7 (0.4) to 28.3 (0.4) kg/m² (P<0.01). Lean soft tissue increased to 3% above baseline level after 15 years (P<0.001). Body fat decreased 9% during the first year of treatment (P<0.001 vs baseline), then increased and had returned to baseline level after 15 years. Total cholesterol decreased from 6.0 (0.1) to 5.5 (0.1) mmol/l and LDL cholesterol decreased from 4.0 (0.1) to 3.3 (0.1) mmol/l (both P<0.001 vs baseline). HDL cholesterol increased from 1.2 (0.03) to 1.4 (0.04) mmol/l (P<0.001 vs. baseline). There was an increase in fasting plasma-glucose from 4.4 (0.1) at baseline to 4.8 (0.1) mmol/l at study end (P<0.001). However, HbA1c decreased from 5.0 (0.1) % to 4.6 (0.1) % (P<0.001).

Conclusions: Fifteen-year GH replacement in GHD adults induced a transient decrease in body fat and sustained improvements of lean soft tissue and lipid profile. Fasting plasma glucose increased whereas HbA1c was reduced.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This work was supported, however funding details unavailable.