Risk Factors for Weight Gain and Metabolic Syndrome in Adolescents with Psychiatric Disorders: A Historical Prospective Study

Objective: Adolescents with mental disorders are at increased risk for being overweight or obese, and subsequently developing metabolic syndrome. However, data regarding risk factors for weight gain during psychiatric hospitalization of adolescents are limited and inconsistent. The aim of this study was to investigate the sociodemographic, clinical, and pharmacological risk factors for weight gain during psychiatric treatment, in order to improve prevention of subsequent metabolic syndrome. Methods: We conducted a historical prospective study of 146 adolescent patients (mean age 15.2±1.9 years, 52.7% males), consecutively admitted for day treatment in an adolescent day unit (length of stay 141±76 days). Anthropometric measurements and laboratory analyses of fasting glucose and lipid levels were conducted as part of the routine medical care at admission and discharge. Psychiatric diagnoses, medication histories, and sociodemographic data were obtained from the electronic medical records system. Results: A significant increase in age- and gender adjusted body mass index (BMI) (i.e., z score) was observed (0.5±1.2 vs. 0.7±1.1 at admission and discharge, respectively, p<0.001). Male subjects were more prone to weight gain than females (odds ratio [OR]=3.5, 95% CI=1.2-10.3) and BMI z score at admission was inversely associated with weight gain (R²=0.2, p<0.0001). Surprisingly, age at admission, psychiatric diagnoses, length of stay, and number of medications were not associated with weight gain. Despite weight gain, fasting blood glucose and lipid profile did not change significantly during the study period. Conclusions: Hospitalization of adolescents in a psychiatric day unit may be associated with a significant weight gain, especially in male subjects and those with normal weight at admission. Efforts should be aimed to reduce weight gain among youth with psychiatric disorders during treatment, to avoid a subsequent metabolic syndrome.