Differences in Metabolic Factors Between Antipsychotic-Induced Weight Gain and Non-pharmacological Obesity in Youths

Background: Youth exposed to antipsychotics may experience several metabolic consequences that often limit the effectiveness of this class of drugs. Objectives: The aim of this study was to compare several metabolic markers between subjects who experienced antipsychotic-induced weight gain and untreated obese patients. Methods: Nineteen non-diabetic youth (mean age 159 months, mean body mass index z-score 1.81) experiencing antipsychotic-induced weight gain and an age-, sex-, and body mass index-matched group of non-diabetic obese patients with no record of treatment (n = 19, mean age 147 months, mean body mass index z-score 2) were compared for a wide range of metabolic factors using a Bioplex Multiplex system. Results: C-peptide, glucose-dependent insulinotropic polypeptide, and adipsin were significantly higher in the antipsychotic-induced weight gain group, whereas visfatin was significantly higher in the untreated obese patients. When age, sex, pubertal status, and body mass index were controlled, C-peptide, glucose-dependent insulinotropic polypeptide, and visfatin remained significant, whereas adipsin fell slightly below the threshold of statistical significance. No other statistically significant difference emerged. Conclusions: Antipsychotic-induced weight gain and untreated obesity showed some similarities, confirming that levels of some hormones, such as leptin and ghrelin, are related to body mass index rather than to antipsychotic exposure. Some differences were also noted; for example, the antipsychotic-induced weight gain group displayed higher C-peptide, glucose-dependent insulinotropic polypeptide, and adipsin, which may reflect β-cell stress and may suggest susceptibility to insulin resistance and lower visfatin, possibly indicating a lower inflammatory status.