Serum brain-derived neurotrophic factor levels and sleep disorders in Chinese healthy and newly diagnosed type 2 diabetic subjects.

Abstract

The aims of the present study were to detect serum brain-derived neurotrophic factor (BDNF) protein concentrations in healthy and diabetic subjects with sleep disorders and to explore correlations among serum BDNF concentrations, metabolic parameters and inflammation. In all, 377 eligible subjects were recruited to the study and underwent a 75-g oral glucose tolerance test. Various clinical parameters of metabolic disorders and cytokines were measured. Sleep disorders were assessed using the Pittsburgh Sleep Quality Index (PSQI). Subjects were grouped into those with normal glucose tolerance (NGT), those with NGT and sleep disorders (NGT-SDi), those with newly diagnosed type 2 diabetes mellitus (T2DM), and those with newly diagnosed T2DM and sleep disorders (T2DM-SDi). Serum BDNF levels were higher in the NGT-SDi and T2DM-SDi subgroups than in the NGT and T2DM groups, respectively. Multiple linear regression analysis revealed that serum BDNF concentrations were independently correlated with PSQI scores, homeostasis model assessment of insulin resistance, and HbA1c, interleukin 6 and tumor necrosis factor-α concentrations (P <0.05 for all). Binary logistic regression analysis revealed that significant associations remained between serum BDNF concentrations and sleep disorders after adjustment for glucose- and metabolic-related factors in both the NGT-SDi and T2DM-SDi subgroups. Serum BDNF concentrations were higher in patients with sleep disorders and were associated with various metabolic parameters and inflammatory cytokines.