Association of plasma retinol-binding protein-4, adiponectin, and high molecular weight adiponectin with metabolic adversities in patients with schizophrenia

Abstract

Metabolic adversities are prevalent in patients with schizophrenia. Retinol-binding protein 4 (RBP4) and high molecular weight (HMW) adiponectin have been recently found to be associated with metabolic features in non-psychiatric population. The study aimed to evaluate the associations between metabolic features and RBP4, total adiponectin, and HMW adiponectin in patients with schizophrenia. We recruited 109 patients with schizophrenia treated with clozapine or haloperidol and evaluated their body mass index (BMI), waist circumference, blood pressure, and fasting triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), fasting plasma glucose, insulin, RBP4, total adiponectin, and HMW adiponectin levels. We found that patients with metabolic syndrome (MS) had higher RBP4 level, and lower total adiponectin and HMW adiponectin levels than those without MS. There were no significant differences in metabolic features and adipocytokine levels between patients treated with clozapine and haloperidol. Most of the metabolic indexes were significantly correlated with the levels of adipocytokines. After adjusting the effects of age, gender, and BMI, marginal significant correlations existed between TG and RBP4 levels; HDL-C and total adiponectin and HMW adiponectin; insulin and HOMA-IR and HMW adiponectin. Receiver operating curve analysis showed that all of the three adipocytokines could differentiate patients with MS from those without MS. Meanwhile, total adiponectin and HMW adiponectin, but not RBP4, had the differentiating power for insulin resistance. Higher RBP4 and lower total adiponectin and HMW adiponectin levels were observed in schizophrenic patients with MS. Only HMW adiponectin is marginally correlated with insulin sensitivity. The finding that metabolic profiles, but not the antipsychotic types, are associated with adipocytokine levels should be confirmed in longitudinal studies.