Weight gain and metabolic abnormalities during extended risperidone treatment in children and adolescents

The aim of this study was to investigate the prevalence of clinical and laboratory metabolic abnormalities during long-term risperidone treatment in children and adolescents.

Medically healthy 7- to 17-year-old children chronically treated, in a naturalistic setting, with risperidone were recruited through child psychiatry clinics. Anthropometric measurements and laboratory testing were conducted. Developmental and medication histories were obtained from medical records.

In 99 patients treated with risperidone for an average of 2.9 years, a significant increase in age- and gender-adjusted weight and body mass index (BMI) (i.e., z-scores) was observed. Concomitant treatment with psychostimulants did not attenuate this weight gain. Risperidone-associated weight gain was negatively correlated with the BMI z-score obtained at the onset of risperidone treatment. Compared to lean children, overweight and obese children had higher odds of metabolic abnormalities, including increased waist circumference, hypertriglyceridemia, and low high-density lipoprotein cholesterol (HDL-C). They also tended to have a higher insulin level and homeostasis model assessment insulin resistance (HOMA-IR) index. As a result, upon recruitment in the study, children with excessive weight were 12 times more likely to have at least one laboratory metabolic abnormality and seven times more likely to have at least one criterion of the metabolic syndrome compared to lean subjects. In contrast to excessive weight status, gaining > or =0.5 BMI z-score point during risperidone treatment was not associated with a significantly higher occurrence of metabolic disturbances.

The long-term use of risperidone, especially when weight is above normal, is associated with a number of metabolic abnormalities but a low prevalence of the metabolic syndrome phenotype. Future studies should evaluate the stability of these abnormalities over time.