Inflammation and Cognitive Function in Overweight and Obese Chinese Individuals.

Background: The role(s) of inflammation in obesity-associated cognitive decline in overweight or obese populations is not completely understood. Objective: To investigate the profile of plasma inflammatory cytokines in overweight and obese Chinese individuals and to assess the relationship between inflammation and cognitive function. Methods: We evaluated the cognitive domains of 282 Chinese adults, aged 35 to 64 years, using the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). The participants were classified into three groups according to their body mass index. Inflammatory cytokines were determined by immune turbidimetric analysis and enzyme-linked immunosorbent assay. Data were analyzed using covariance and partial correlation analyses after adjusting for gender, age, education level, hypertension, and hyperlipemia. Results: The total MoCA scores of the overweight and obese groups were significantly lower than that of the control group. The obese group displayed a significantly higher level of tumor necrosis factor-alpha than the overweight and control groups and a significantly higher level of transforming growth factor-beta than the control group. The overweight group displayed a significantly higher interleukin-4 level than the control and obese groups. After adjusting for confounding factors, however, we found no significant correlation between the level of plasma inflammatory cytokines and MMSE or MoCA total score. Conclusions: Compared to normal-weight Chinese participants, overweight and obese Chinese participants revealed significant differences in their inflammatory cytokines profile; however, the inflammatory cytokine levels did not correlate with the significantly lower cognitive scores observed in the overweight and obese groups.