Cardiometabolic biomarkers and comorbid metabolic syndrome in schizophrenia: A cross-sectional study of long-term clozapine/ olanzapine users

Objectives: Second-generation antipsychotics (SGAs) are often prescribed for patients with schizophrenia; however, SGAs are associated with the risk of metabolic syndrome (MetS). This study aimed to investigate the clinical and biochemical determinants of SGA-related MetS. Methods: Patients with schizophrenia, aged between 20 and 65 years, and under clozapine or olanzapine treatment for at least 9 months, were recruited from a mental hospital. Demographic, comorbidity, clinical status, laboratory, and drug regimen data were collected through chart review. Circulating levels of adiponectin, thyroid hormone responsive protein, and fatty acid binding protein 4 (FABP4) were assayed. Multiple logistic regression was used to identify risk predictors of MetS. Results: A total of 176 participants were enrolled, including 138 (78.4 %) clozapine users and 38 (21.6 %) olanzapine users. Forty-five (25.6 %) patients were classified as having MetS. The duration of clozapine or olanzapine usage was significantly shorter in those with MetS (p=0.026) =0.026) than those without MetS. Patients with MetS had a significantly higher serum FABP4 concentration than their counterparts (22.5 +/- 8.8 ng/mL vs. 15.7 +/- 6.7 ng/mL, p<0.001), and also a significantly lower adiponectin level (6.9 +/- 4.0 mg/mL vs. 11.6 +/- 6.6 mg/mL, p<0.001). A FABP4 level >= 16.98 ng/mL (OR: 24.16, 95 % CI: 7.47-78.09, p<0.001) was positively correlated with MetS, whereas serum adiponectin level was inversely correlated with MetS (OR: 0.7980, 95 % CI: 0.70-0.90, p<0.001). Conclusions: Adiponectin, FABP4, and certain clinical covariates and comedications were highly correlated with SGA-related MetS. Further studies are required to investigate the underlying mechanisms.