Cardiovascular risk factors improve during 3 years of growth hormone therapy in Prader-Willi syndrome

Cardiovascular risk factors in Prader-Willi syndrome (PWS, OMIM 176270) may be independently caused by overweight or hypothalamic growth hormone (GH) deficiency. The present observational study in 23 children with PWS, aged 0.3-14.6 years, focuses on the specific pattern, age-dependency and interrelation of cardiovascular risk factors, namely percentage fat mass and regional fat distribution, triglycerides (TG), lipoprotein cholesterols (LDL-C, HDL-C), lipoprotein (a) (Lp(a)), apolipoproteins A-I (Apo A-I) and B (Apo B), as well as on the longer-term effects of GH therapy (ca. 0.037 mg/kg per day for 3 years on average). We report that in children above 4 years, percentage body fat was increased in all and waist-to-hip-ratio (WHR) in 35%. Abnormal levels of LDL-C, Apo B, HDL-C and TG were found in 6, 7, 6 and 3 children, respectively. Lp(a) was above 300 mg/l in 5 patients and remained unchanged during GH therapy. However, percentage fat mass dropped to the upper normal range and WHR became normal in all patients receiving GH therapy, as did the ratio of LDL-C to HDLC, subsequent to decreasing LDL-C and increasing HDL-C. Nevertheless, we could not find any significant correlation between parameters of total fat mass or fat distribution and serum lipid parameters, except for abdominal fat distribution (trunk-/leg-fat ratio) to TG before therapy. Conclusion Several cardiovascular risk factors are already present in prepubertal children with Prader-Willi-syndrome and they are improved by growth hormone treatment, acting both on body composition and lipid metabolism.