Endocrine Abstracts

Introduction: PWS is the most common cause of genetic obesity. These patients have an abnormal body composition with increased amounts of fat mass (FM), reduced lean body mass (LBM) and diminished bone mineral density (BMD), all similar to patients with growth hormone deficiency (GHD).The abnormal body composition has been described due to impairment of the activity of GH-IGF system and to hypogonadism. Studies ongrowth hormone (GH) treatment in PWS adults from other European countries show improvement in body composition without changes in BMD.

Objectives: Our objective was to investigate the effect of GH on body composition in GHD genotype-positive PWS adults who had been under GH therapy for one year.

Design and patients: Twenty-seven PWS patients were diagnosed from GHD through two different stimulation tests: glucagon test and GHR + Harginine test¹. At the time of the study, eighteen of them were undergoing sex steroid replacement therapy. Body composition was examined with DXA (Lunar Prodigy) before and after one year GH therapy. GH was initiated at 0.2 mg/day and adjusted depending on IGF-I values (values had to be at the upper part of the range). Total body water was estimated by bioelectrical impedance.

Results: Baseline body composition was: LBM 45.0 ± 1.35%, 38.6 ± 1.6 kg, total FM 54.4 ± 1.34%, 48.9 ± 3.0 kg. After one year of GH therapy, LBM increased significantly in 2.1% (P 25–75: 0.7–3, P = 0.03), 3.1 kg (P 25–75: 0.04–6.2 kg, P = 0.05), and total FM decreased also significantly in –1.6% (P 25–75: –0.5–2.7, P = 0.005), –1.9 kg (P 25–75: –0.5–3.3 kg, P = 0.01). Total body water increased in 0.5 kg, 0.7% (P = 0.06). In relation to BMD, pre-treatment Z scores were lower than expected for age (lumbar spine Z–1.3 ± 0.3 s.d., total femur Z–1.2 ± 0.24 s.d.; femur neck Z–1.1 ± 0.25 s.d.). No significant changes were seen after one year of GH therapy. There was no correlation between the increase in IGF-I and changes in LBM and FM. No severe side effects were reported.

Conclusion: Our results are consistent with previous data and show that one-year treatment with GH in adult patients with PWS is safe, effectively improves body composition and does not change low bone mineral density.

Reference

1. Disease State Clinical Review, Endocr Pract. 2016 22(10) 1239.