Cognitive function during 3 years of growth hormone in previously growth hormone-treated young adults with Prader–Willi syndrome

Abstract

Context Most patients with Prader-Willi syndrome (PWS) have a mild to moderate cognitive impairment. Growth hormone (GH) treatment has positive short- and long-term effects on cognition in children with PWS. Few studies, however, have investigated the effects of GH on cognitive functioning in adults with PWS. Objective To investigate the effects of 3 years GH treatment on cognitive functioning and behavior in young adults with PWS who were treated with GH during childhood. Design Open-label, prospective study. Setting Dutch PWS Reference Center Methods Patients were treated with 0.33 mg GH/m²/day (∼0.012 mg/kg/day; 33% of childhood dose). Cognitive functioning was measured by Wechsler Adult Intelligence (WAIS) tests. Behavior was studied by Developmental Behavior Checklist – Parents/caregivers (DBC-P). Results 46 young adults with PWS with a median age of 19 (IQR 17–21) years were investigated. Estimated mean (95% CI) total, verbal and performance IQ remained stable during 3 years of GH-treatment. Total IQ being 66 (63-69) at start and 67 (64-71) after 3 years (p=0.30); Verbal IQ being 65 (62-68) and 66 (62-70), resp. (p=0.31) and performance IQ being 67 (63-70) and 67 (63-72) resp. (p=0.42). Estimated mean Total DBC score did not significantly change during 3 years of GH-treatment, being 36.3 at start and 36.5 after 3 years (p=0.94) (P50). Conclusions Three years of GH-treatment in young adults with PWS with 33% of the pediatric dose, maintains total, verbal and performance IQ. The emotional and behavioral disturbances remained stable and were similar compared to peers with other intellectual disabilities.