Elevated levels of adiponectin and other cytokines in drug naïve, first episode schizophrenia patients with normal weight.

OBJECTIVE

The study was to examine the levels of adiponectin (APN) and other cytokines, and body metabolism in drug naïve, first episode schizophrenia patients with normal weight.

METHODS

Ninety-six drug naïve, first episode schizophrenia patients with normal weight (SZ group), 60 healthy individuals with normal weight (control group), and 60 overweight or obese but otherwise healthy individuals (obesity group) were enrolled in the study. Serum levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and APN were measured using enzyme linked immunosorbent assay (ELISA). Glucose oxidase was used to measure plasma glucose level. Lipid levels were measured using the enzymatic colorimetric method.

RESULTS

Serum levels of IL-1β, IL-6 and TNF-α in both the SZ group and the obesity group were significantly higher than those in the control group (p's<0.001). There were no significant differences between the SZ group and the obesity group on those cytokines (p's>0.05). In addition, the levels of APN were significantly higher in the SZ group (p<0.001), and significantly lower in the obesity group (p<0.01) compared with the control group. Further, there were significant positive relationships between levels of APN and levels of other cytokines within the SZ group (p's<0.05); in contrast, there were significant negative relationships between levels of APN and levels of other cytokines within the obesity group (p's<0.05). Fasting serum levels of glucose, LDL, triglycerides and total cholesterol were significantly higher, and fasting serum levels of HDL were significantly lower in the obesity group compared with the other two groups (p's<0.01). There were no significant differences in any of the metabolic parameters between the control group and the SZ group (p's>0.05).

CONCLUSIONS

Drug naïve, first episode schizophrenia patients with normal weight seem to present an up-regulated inflammatory status as reflected by elevated levels of IL-1β, IL-6, and TNF-α. APN may play a unique pro-inflammatory role in this patient population. Implications of the findings in relation to the pathogenesis of schizophrenia and the vulnerability for metabolic problems were discussed.