Plasma brain-derived neurotrophic factor and dynamic cerebral autoregulation in acute response to glycemic control following breakfast in young men

We examined the acute impact of both low- and high-glycemic index (GI) breakfasts on plasma brain-derived neurotrophic factor (BDNF) and dynamic cerebral autoregulation (dCA) compared to breakfast omission. Ten healthy men (age 24 ± 1 yrs) performed three trials in a randomized crossover order; omission, Low- (GI = 40), and High-GI (GI = 71) breakfast conditions. Middle cerebral artery velocity (transcranial Doppler ultrasonography) and arterial pressure (finger photoplethysmography) were continuously measured for 5-mins prior to and 120-mins following breakfast consumption, to determine dCA using transfer function analysis. After these measurements of dCA, venous blood samples for the assessment of plasma BDNF were obtained. Moreover, blood glucose was measured before breakfast and every 30 mins thereafter. The area under the curve of 2-hours post-prandial blood glucose in the High-GI trial was higher than Low-GI trial (P < 0.01). The GI of the breakfast did not affect BDNF. In addition, both very low- (VLF) and low-frequencies (LF) transfer function phase or gains were not changed during the omission trial. In contrast, LF gain (High-GI P < 0.05) and normalized gain (Low-GI P < 0.05) were decreased by both GI trials, while a decrease in VLF phase was observed in only the High-GI trial (P < 0.05). These findings indicate that breakfast consumption augmented dCA in the LF range, but High-GI breakfast attenuated CBF regulation against slow change (i.e., the VLF range) in arterial pressure. Thus, we propose that breakfast and glycemic control may be an important strategy to optimize cerebrovascular health.