Poster Topical Area: Energy and Macronutrient Metabolism
Location: Hall D
Poster Board Number: 411
Objectives: Exercise training ultimately improves health, but acute exercise triggers an increase in blood pressure (BP), which may be disadvantageous to health. Chronic ingestion of elevated dietary protein can reduce blood pressure. Therefore, consumption of a higher-protein meal may attenuate the acute hypertensive response to exercise and allow individuals at risk for hypertension to experience the health benefits of both acute exercise and training. We hypothesized that the consumption of a meal with 30g protein (HP; 23g from egg sources) would attenuate exercise-induced systolic BP elevation and improve BP-related markers of endothelial function, compared with an isocaloric 13g protein meal (LP; 7g from egg sources).
Methods: 31 subjects (18 M, 13 F; age 33 ± 14 y; BMI 26.5 ± 3.8; Systolic BP 127 ± 5 mm Hg, Diastolic BP 77 ± 6 mm Hg) completed this randomized, double-blind, cross-over acute feeding study. On each testing day, subjects consumed either a HP or LP meal and 165 minutes later, exercised on a cycle ergometer at 70% VO2 max for 30 minutes. BP was measured immediately prior to the meal (0 min) and periodically before, during, and after exercise over a 315-min period. Concurrent with BP measurements, blood was sampled to determine endothelial function via quantification of plasma nitrites, nitrates, endothelin-1, arginine and arginine metabolites.
Results: Consuming a HP meal did not attenuate BP responses to exercise. There was no differential response in 30 minute composite systolic BP iAUC (LSmean ± SE; HP 464 ± 37, LP 457 ± 37 mm Hg; P=0.76) or peak systolic BP (HP 190 ± 5, LP 190 ± 5 mm Hg; P=0.90) during exercise by meal. Time for systolic BP to return to baseline post-exercise BP (3 min recovery ratio; HP 0.80 ± 0.02, LP 0.78 ± 0.02; P=0.49) and post-exercise systolic BP iAUC (HP 102 ± 15, LP 67 ± 15 mm Hg; P=0.07) were not influenced by protein intake. There was no differential response in any plasma marker of endothelial function during exercise by meal.
Conclusion: These results suggest that the chronic beneficial effects of consuming greater dietary protein on BP do not manifest in acute settings in which participants consume higher protein meals and the cardiovascular system is challenged with aerobic exercise.
American Egg Board-Egg Nutrition Center