The effects of atypical antipsychotic usage duration on serum adiponectin levels and other metabolic parameters

The relationship between serum adiponectin levels, cardiometabolic indices and metabolic syndrome in schizophrenia

BACKGROUND

Adiponectin is a hormone secreted by adipose tissues that is thought to influence lipid and glucose metabolism, and the development of metabolic derangements, including metabolic syndrome (MetS), in schizophrenia. We aim to determine the serum adiponectin levels in Chinese patients with schizophrenia, and explore the relationship between adiponectin levels and metabolic parameters, including MetS and its components. We hypothesized that serum adiponectin levels are similar in schizophrenia patients and controls, but decreased amongst patients on atypical antipsychotics.

METHODS

81 patients and 81 controls were recruited. Anthropometric parameters and fasted blood samples for metabolic measurements were obtained. Serum adiponectin levels were measured using Bioplex assays.

RESULTS

There was no difference in median adiponectin levels between schizophrenia patients and controls. Those taking typical antipsychotics alone had lower median adiponectin levels than those on mixed typical and atypical antipsychotics. Serum adiponectin level, controlled for age, gender and body mass index, was positively correlated with high-density lipoprotein cholesterol, and negatively correlated with diastolic blood pressure, total cholesterol, low-density lipoprotein cholesterol, and triglyceride levels in schizophrenia patients. Patients with MetS had lower median adiponectin levels than those without MetS, and serum adiponectin levels decreased as the number of MetS components increased. After adjusting for variables thought to influence MetS, our logistic regression model did not reveal any significant association between adiponectin levels and MetS in schizophrenia patients.

CONCLUSION

Our findings highlight the need for more studies focusing on serum adiponectin level and its relationship with MetS in schizophrenia, particularly in those taking typical antipsychotics.

Second-generation antipsychotics and adiponectin levels in schizophrenia: A comparative meta-analysis

People with schizophrenia treated with second-generation antipsychotics (SGAs) have lower plasma adiponectin levels, as compared with general population, that may lead to metabolic abnormalities. However, the contribution of different SGAs on adiponectin dysregulation is still unclear. The objective of this systematic review and meta-analysis was to estimate differences in adiponectin levels among people with schizophrenia treated with different SGAs. We systematically searched for observational studies published up to March 2015 in main electronic databases. Different SGAs were included if data on adiponectin were available from at least three different samples involving as a minimum five participants per treatment arm. Standardized mean differences with relevant 95% confidence intervals were generated. I(2) was used to test heterogeneity among studies. Eight studies were included with data suitable for carrying out four different comparisons: Clozapine vs. Olanzapine (including n=877 individuals with schizophrenia); Clozapine vs. Risperidone (n=660); Olanzapine vs. Risperidone (n=738); Quetiapine vs. Risperidone (n=186). There were no differences on adiponectin levels between people taking Clozapine and those taking Olanzapine (p=0.86), but high heterogeneity was detected (I(2)=82%). Both individuals taking Clozapine (p<0.001; I(2)=0%) and those taking Olanzapine (p=0.02; I(2)=9%), but not subjects treated with Quetiapine (p=0.47; I(2)=0%), had adiponectin levels significantly lower than people taking Risperidone. Our findings are consistent with previous evidence showing greater metabolic abnormalities attributable to Clozapine and Olanzapine, as compared with other SGAs. Although mechanisms whereby both these SGAs influence adiponectin remain unexplained, its reduction might mediate relevant abnormalities. Prospective evaluations of long-term effects of different SGAs on adiponectin are needed.