Acute and chronic effects of aerobic exercise on serum brain-derived neurotrophic factor in patients with coronary artery disease

Abstract Background The relationship between aerobic exercise and brain-derived neurotrophic factor (BDNF) is well established in healthy and clinical populations, yet evidence in patients with cardiovascular disease remains limited. This is notable because BDNF contributes to vascular integrity, angiogenesis, and cardiac contractility, suggesting that exercise-induced changes may reflect meaningful cardiovascular adaptations. Furthermore, patients with coronary artery disease (CAD) consistently exhibit lower circulating BDNF than healthy individuals. Understanding how aerobic exercise influences BDNF in this population may therefore provide insight into cardiovascular benefits and inform exercise prescription in cardiac rehabilitation. Because different aerobic-training modalities may differentially modulate acute and chronic BDNF responses, it is important to determine whether the type of training influences these adaptations in patients with CAD. Purpose The aim of the current study was to investigate the acute and chronic effect of three aerobic exercise modalities on serum BDNF levels in patients with CAD. Methods Twenty patients with CAD (myocardial infarction n = 16; stable angina n = 4) were randomised to moderate-intensity continuous training (MICT; n = 7), high-intensity training with short intervals (short-HIIT; n = 6), and with long intervals (long-HIIT; n = 7). Serum BDNF was measured before and one min after a cardiopulmonary exercise test (CPET) at baseline, after 6 weeks, and 12 weeks. Normality was assessed using the Shapiro–Wilk test. Changes in BDNF were analysed with a mixed ANOVA with two within-subject factors (Acute, Chronic), and one between-subject factor (Group). Interactions between the three factors were investigated, and main or simple effects were reported. Eta squared (η2) was used as effect size index, and values higher than 10% were considered relevant. Mean differences (MD) and 95% confidence intervals (95% CI) were reported. Results The results showed a relevant interaction between acute and group factors (p = .222; η2 = 16.2). We found significant acute BDNF increases in both HIIT groups: short-HIIT (MD = 11.52 ng/mL, 95% CI 4.78, 18.26, p = .002) and long-HIIT (MD = 10.28 ng/mL, 95% CI 2.99, 17.56, p = .008). In contrast, the MICT group showed no significant change (MD = 3.83 ng/mL, 95% CI -2.91, 10.57, p = .247). No changes in serum BDNF levels were found after the intervention, regardless of the training group. Conclusions Acute BDNF responses differed by training modality, with significant increases in both HIIT groups. Across all assessment points, HIIT consistently elicited a stronger acute BDNF response, suggesting greater vascular responsiveness to exercise stress. No chronic changes in resting BNDF were observed in any group. These findings support HIIT as an effective modality in cardiac rehabilitation, with potential benefits concerning molecular pathways relevant to cardiovascular health.