ESPE Abstracts

Introduction: PWS is a congenital hypothalamic disorder characterized by short stature and obesity due to hyperphagia. Early growth hormone therapy (GHT) has been shown to positively alter the phenotype of the disease and improve final height, BMI, body composition, and metabolic parameters. The aim of this study was to analyze the course of BMI and body composition during the first year after cessation of GHT.

Methods: Retrospective analysis of n = 55 patients (n = 26 female) with genetically confirmed PWS. All patients followed a PWS-specific nutritional and physical activity management program in a stable environment at PWS centers in Hildesheim and Augsburg, Germany. Body composition was analyzed at 0, 6, and 12 months after GHT by bioelectrical impedance analysis.

Results (median, quartiles): CA at cessation of GHT was 15.8yrs (14.9;16.4) in males and 14.7yrs (13,8;15,2) in females. DeltaBA was 0.30yrs (-0.20;1.40) in males and -0.10yrs (-1.05;0.30) in females. Delta to parental height was -6.90 cm (-11.3;-3.50) in males and -11.,75 cm (-19.4;-3.25) in females. IGF1 and IGFBP3 levels decreased significantly (P <0.005) at month (m) 6 and 12. IGF1 [µg/L] in males was: 0m: 430 [350;504], 6m: 224 [163;291], 12m: 208 [183; 265], and in females: 0m: 460 [320;546], 6m: 244 [198;296], 12m: 201 [166; 243] IGFBP3 followed a similar pattern. BMI increased significantly (males P = 0.0026; females P <0.0001). Body composition showed an increase in body fat (BF) (males and females P = 0,0003), an increase in total body water (TBW) in females only (males P = 0,324, females P = 0.0127), and no significant changes in lean body mass (LBM) (males P = 0.6038, females P = 0.2436), and phase angle (PA) (males P = 0.0587, females P = 0.0613). Physical activity did not change during this year. However, a subgroup analysis of those (n = 17) with a more pronounced decrease of IGF1 at month 6 below 200 µg/L showed no changes in BMI. Interestingly, BF, LBW, and PA showed no significant differences after 12 months as well. Additionally, physical activity showed significant differences between those with 0 to 2 versus 3 to 6 activities per week. BMI and PA improved after 12 months compared to less activity (P = 0.0136, P = 0.0485).

Conclusion: After cessation of GHT, adolescents with PWS showed an increase in BMI and alterations of body composition. However, a clear relation to decreased growth factors cannot be established by this study. Physical activity also appears to have a measurable positive impact. Nevertheless, a multiprofessional management approach in patients with PWS is mandatory.