Decreased serum brain-derived neurotrophic factor in Chinese patients with Type 2 diabetes mellitus.

Abstract

It was also found that the serum BDNF levels in Chinese patients with T2DM were significantly lower than those in healthy controls. The BDNF levels in female patients with T2DM were higher than those in male patients. In Chinese patients with T2DM, the serum BDNF level was associated with HDL-C. These results suggested that the serum BDNF levels are different between females and males and its level reflects the lipid and glucose metabolism. Patients with T2DM also have higher BMI than the controls. So the phenomenon that the BDNF level was lower in patients with T2DM could be explained by the effect of BDNF on obesity. Some previous results demonstrated that plasma BDNF levels were significantly lower in patients with T2DM compared with non-diabetic subjects. Suwa et al .[ 4] reported that serum BDNF levels in newly diagnosed female patients with T2DM were significantly higher than those in controls. In the present study, we observed lower serum BDNF levels in patients with T2DM than in healthy controls and higher levels in female than in male patients. Our study supports the hypothesis that patients with long-standing diabetes may have lower serum BDNF levels [9]. A previous study demonstrated that plasma or serum levels of BDNF were decreased in patients with T2DM [9]. Inverse correlation between serum BDNF levels and duration of diabetes was also found. Another study showed higher serum BDNF levels in newly diagnosed female patients with T2DM [4]. These inconsistent findings may be due to the duration of diabetes. It was hypothesized that insulin resistance in newly diagnosed T2DM patients contributes to higher levels of serum BDNF [4]. The lower serum BDNF levels were found in young non-obese subjects with low insulin sensitivity [8]. In summary, we found that the serum BDNF levels were lower in Chinese patients with T2DM than those in the healthy controls and its levels were higher in female patients