Relationship between antipsychotics and weight in patients with Prader-Willi syndrome

Abstract

Background: Individuals with Prader-Willi Syndrome (PWS) are at increased risk for developing behavioral and psychiatric disorders, often requiring antipsychotics (APs). Contrary to significant AP-associated weight gain observed in the general population, existing literature suggests weight loss in patients with PWS.

Study objective: To evaluate the relationship between AP use and body mass index (BMI) at admission, change in BMI during inpatient stay, and length of stay (LOS) in patients admitted to an inpatient PWS treatment program.

Design: Retrospective case-control study.

Setting: Hospital-based, inpatient PWS treatment program serving nationally and internationally referred children and adults with PWS.

Patients: Cases consisted of 52 pediatric patients with PWS who were taking APs at admission and during their stay, 97 adults with PWS who were taking APs at admission and during their stay, and 11 pediatric and adult patients with PWS who were AP naïve at admission and subsequently started an AP during their stay; all cases were matched with patients with PWS who were AP naïve at admission and during their stay by age (yrs), sex, and race-ethnicity (controls).

Measurements and main results: Between- and within-group differences in admission BMI, BMI change from admission to discharge, and LOS were analyzed. Admission BMI was lower (mean ± SD 36.8 ± 11.9 kg/m(2) vs 46.7 ± 12.5 kg/m(2) , p<0.001) and LOS longer (mean ± SD 75.9 ± 38.5 days vs 57.8 ± 23.2 days, p=0.005) for pediatric cases with AP exposure at admission and during their stay compared with matched controls. All groups experienced significant decreases in BMI from admission to discharge (p≤0.001 for all comparisons), except for pediatric cases with AP exposure at admission and during their stay. Cases that were AP naïve at admission and subsequently started an AP during their inpatient stay experienced a significantly smaller decrease in BMI from admission to discharge than matched controls (-3.011 vs -7.288 kg/m(2) , p=0.027). No other comparisons between cases and controls were significantly different.

Conclusion: On average, patients with PWS who were prescribed APs lost weight during their inpatient stay, but this varied with patient age and duration of AP use.

Keywords: antipsychotics; drug safety; obesity.