Short-term effect of two caffeine-beetroot supplementation rate on TNF-α, GDF15 and E-SELECTIN following a course of aerobic activity in professional endurance runners

Chronic inflammation as an integral part of cardiovascular disease is associated with endothelial dysfunction. The aim of this study was to evaluate the effect of pre-intensive aerobic workout caffeine-beetroot supplementation on indicators related to vascular function including endothelial selectin (E-SELECTIN), growth differentiation factor-15 (GDF-15) and tumor necrosis factor-alpha (TNF-α) in elite  endurance runners.

In this experimental study, 10 elite male runners (age: 27.5±3.8 y, height: 176.7±7.8 cm, BMI: 22.3±1.5 kg/m2 and VO2max 52.2±4.6 ml/kg/min, were selected and with a double-blind, counterbalance, crossover and randomized design, were participated into three short-term conditions with 2 week washout. 1: high dose (9.6 mmol nitrate and 400 mg caffeine), 2: low dose (4.8 and 200) and 3: placebo. Subjects consumed 250cc of the supplement twice daily. Aerobic exercise included 5-km high intensity indoor running.

intervention, conditions and time effects with MANOVA repeated measures and bonferroni statistical analysis tests showed that the short term beetroot-caffeine supplementation (intervention effect) had no significant effect on E-SELECTIN and GDF-15, but decreased TNF-α (p=0.038). Also, that increased the GDF-15 (p=0.024), TNF-α (p=0.0001) and E-SELECTIN (p=0.047) and the supplementation after seven days (time effect) decreased the levels of TNF-α (p=0.033), GDF-15 (p=0.021) and E-SELECTIN (p=0.004) following exercise. 

an increase in the variables after exercise and decrease after seven days of the supplementation, indicates that may improves cardiac dysfunction caused by intensive aerobic exercise.