Metabolic and glutathione redox markers associated with brain-derived neurotrophic factor in depressed African men and women: evidence for counterregulation?

Abstract

Background: Major depression is associated with evidence for metabolic and redox imbalance and also with reports of lower serum levels of brain-derived neurotrophic factor (BDNF). However, the relationship between these factors has not been well studied. Methods: We studied the contribution of physiological risk factors to cardiometabolic health in 200 adult male and female black Africans, aged between 36 and 52 years, presenting with (n = 89) and without (n = 111) symptoms of depression. Specifically the association between serum BDNF and markers of basal metabolic and redox status in depressed versus nondepressed individuals were analyzed. Results: BDNF and markers of redox and metabolic status were not associated with the symptoms of depression. Waist circumference, a metabolic risk factor, was positively associated with BDNF and accounts for 49% of the variance in BDNF in depressed men. Reduced and oxidized glutathione were positively and negatively correlated with BDNF in depressed women, respectively, with glutathione redox status accounting for 36–42% of the variance in BDNF. Conclusion: Selected metabolic and redox factors explained gender-specific variances in serum BDNF levels in depressed African men and women. Our findings suggest that changes in redox and metabolic status may represent counterregulation by BDNF or alternatively that BDNF may mediate undesirable redox and metabolic changes that are associated with the development of a mood disorder.