Leptin/Adiponectin ratio as a potential biomarker for metabolic syndrome in patients with schizophrenia

Abstract Objective Leptin and adiponectin are adipokines which have opposing roles in the development of insulin resistance and metabolic syndrome (MetS). Leptin/adiponectin ratio (L/A ratio) has been proposed as a good biomarker for MetS in general population. This study aimed to compare the strength of association between MetS and leptin, adiponectin and L/A ratio, as well as to assess their performance to diagnose MetS in patients with schizophrenia. Methods Patients diagnosed with DSM-IV schizophrenia and under clozapine or olanzapine monotherapy for at least six months were recruited. We used the modified ATP III criteria for Asians to evaluate subjects for a diagnosis of MetS. Results We recruited 262 study subjects with schizophrenia, and classified them into those with MetS (n = 87) and those without MetS (n = 175). Leptin level was positively correlated with BMI, waist circumference, and insulin level. Adiponectin level was negatively correlated with most metabolic parameters, except glucose level. L/A ratio was positively correlated with most metabolic parameters, except levels of glucose and HDL-C. Significant gender differences existed in leptin levels, adiponectin levels, and L/A ratio. Without and with adjustment of age and gender, binary logistic regression analysis showed that leptin level, adiponectin level, and L/A ratio were significantly associated with MetS. The area under curve (AUC) of L/A ratio and leptin level for MetS was 0.744 (95% CI = 0.685–0.802) and 0.666 (95% CI = 0.601–0.731). The AUC of adiponectin level for the absence of MetS was 0.717 (95% CI = 0.655–0.780). The discriminative strength of L/A ratio for MetS was better in men than in women. Conclusions The present study results suggest that L/A ratio may be a preferential marker of metabolic syndrome in patients with schizophrenia compared to leptin or adiponectin alone.