Attenuated brain derived neurotrophic factor and depression in type 2 diabetes mellitus patients: A case-control study

Abstract

Problem considered: Type 2 diabetes mellitus (T2DM) and depression are two of the most prevalent chronic and devastating diseases. Brain derived neurotrophic factor (BDNF) is postulated to modulate the secretion and actions of insulin. Furthermore, a strong association has been demonstrated between BDNF and depression. Although depression is a common neuropsychiatric comorbidity of T2DM, the association of BDNF levels with depression in T2DM remains unclear. Thus, the purpose of the present study was to assess the serum BDNF levels in healthy controls and T2DM patients and explore the association of serum BDNF levels with depression in T2DM patients. Methods: In this study depression was assessed using Patient Health Questionnaire-9 (PHQ-9) and serum BDNF levels were estimated by ELISA technology. Results: and conclusions: A total of 88 subjects were included in the study. The mean PHQ-9 score for T2DM patients (3.91 ± 5.88) was higher than in healthy subjects (1.02 ± 3.02), p = 0.031. Subsequently, the prevalence of depression was higher in T2DM patients 16 (36.36%) as compared to healthy subjects 5 (11.36%), p < 0.001. The serum level of BDNF was lower in T2DM patients (15.17 ± 2.81 ng/ml) than in healthy subjects (24.65 ± 13.81 ng/ml) than, p < 0.0001. Additionally, serum BDNF levels were lower in T2DM patients with depression (13.87 ± 2.62 ng/ml) than in those without depression (15.92 ± 2.77 ng/ml), p = 0.02. An inverse association was found between BDNF levels and PHQ-9 scores (r2 = 0.2003, p = 0.002). The results suggest that BDNF might influence the presence of depression in T2DM patients. However, further studies are warranted to elucidate the mechanism by which BDNF may influences depression in T2DM patients.

Keywords

• Brain derived neurotrophic factor
• Depression
• Patient health questionnaire
• Type 2 diabetes mellitus