Serum brain-derived neurotrophic factor is associated with diabetic complications and glycemic control in type 2 diabetes: an exploratory analysis of the ADNI cohort

To investigate the association between serum brain-derived neurotrophic factor (BDNF) levels and the clinical profile as well as complications in patients with type 2 diabetes mellitus (T2DM). A total of 185 participants were enrolled, including 35 healthy controls, 111 T2DM patients without complications, and 39 T2DM patients with complications. Serum BDNF levels declined progressively across groups (18.1→13.5→10.2 ng/mL, P < 0.001). BDNF was moderately negatively correlated with HbA1c (ρ=−0.41, P < 0.001) and weakly positively correlated with MoCA scores (ρ = 0.18, P = 0.013). Multivariable regression confirmed that diabetic complications (β=−2.05, P = 0.021) and higher HbA1c (β=−1.03, P < 0.001) were independently associated with lower BDNF. Participants in the lowest BDNF quartile had elevated odds of complications (OR = 16.67, 95% CI 1.56–178.57, P = 0.013). BDNF showed limited discriminative ability for cognitive impairment (AUC = 0.603). Exploratory mediation analysis suggested a potential pathway of BDNF→HbA1c→cognitive function. Serum BDNF is associated with glycemic control and complication burden in T2DM.