Phenotypic characteristics in metabolically healthy but obese patients with schizophrenia

The purpose of this study was to characterize phenotypic characteristics of metabolically healthy but obese individuals with schizophrenia. Participants were non-diabetic outpatients 19 to 75 years old diagnosed with schizophrenia or schizoaffective disorder. Obese patients (body mass index (BMI)>30 kg/m2) were included in the present analysis. Patients were further defined as metabolically healthy but obese or obese individuals with metabolic abnormalities based on a cut-off value of 2.5 using the homeostasis model assessment of insulin resistance (HOMA-IR). Fasting blood samples were collected to determine levels of various metabolic parameters. Lipoprotein subclass concentrations and sizes were analyzed using nuclear magnetic resonance (NMR) spectroscopy. Fourteen metabolically healthy but obese patients and 62 obese patients with metabolic abnormalities were identified from 206 patients with schizophrenia. After controlling for age, there were no significant differences between the two groups on anthropometric measures. However, the metabolically healthy but obese group had significantly lower levels of large VLDL particle, significantly higher levels of intermediate VLDL particle, and significantly smaller mean particle size in VLDL compared with the obese group with metabolic abnormalities (metabolically obese). A metabolically healthy but obese phenotype characterized by high levels of intermediate VLDL particle and low levels of large VLDL particle exists in obese, non-diabetic patients with schizophrenia.