ESPE Abstracts

Introduction: Prader-Willi syndrome (PWS) is a rare paternally inherited genetic disorder caused by alteration of chromosome 15q11-q13. Associated hypothalamic impairment leads to hyperphagia which therefore increases the risk for morbid obesity, dyslipidaemia, insulin resistance and arterial hypertension and in the end increases mortality. Patients with PWS benefit of recombinant growth hormone (rGH) treatment despite the GH reservoir to improve their impaired final height, but GH is known to improve cardiometabolic profile.

Aim: To describe the metabolic profile in rGH treated PWS patients in our centre.

Materials and Methods: Eight children (4 girls and 4 boys) with PWS treated with rGH at a median age of 6.7±3.2 years old were included. Follow-up period was 31±17 months. During the follow-up, 4 children needed levothyroxine, 2 stress hydrocortisone and 1 sex-hormone replacement. Starting rGH dose was 0.53 mg/m2/day. At diagnosis, height was -1.7±0.9 and BMI 20.3±4 SD (Z-score 1.5±0.6). IGF1 level was 0.1±0.8 SD. All patients were prepubertal, excepting one girl with adrenarche corresponding to Tanner 3 at 11.8 years. None of the patients had metabolic impairments - glycemia 77.3±7.5 mg/dL; HbA1c 5±0.4%; total cholesterol (TC) 171.7±29.4 mg/dL. Phospho-calcic parameters were normal - total serum calcium (Ca) 9.9±0.1 mg/dL; serum phosphate (P) 4.8±0.3 mg/dL; alkaline phosphatase (ALP) 0.6±0.2 x upper limit of normal (ULN). At one year of follow-up patients had a median height increase of 0.5 SD and a BMI increase of 0.07 SD. Glycemia, TC and Ca levels were stable. P level increased to 5.2±0.3. ALP increased in 5/8 children with 0.4 points x ULN (P<0.05) and 3/8 patients had stable ALP values. IGF1 at 1.6 SD proved treatment compliance. At the last follow-up, none of the patients completed the rGH treatment; 1/8 had to stop because of increased sleep apnea. Height gain during follow-up was 1 SD. BMI decreased to 1±1.8 SD, but not statistically significant. HbA1c increased to 5.3±0.4%, but none of the patients developed glucose intolerance. TC (168.6±28.7 mg/dL), Ca (9.9±0.4 mg/dL), P (4.9 ±0.2 mg/dL) and ALP (0.8±0.3 xULN) were not significantly changed during the rGH treatment.

Conclusion: No significant metabolic changes were observed in our series of patients, but bigger lots are needed to prove if rGH treatment in childhood could prevent adult-onset metabolic syndrome in these patients, along with lifechanging measures.