L-Arginine Supplementation Improves Post-Exercise Hypotension in Elderly Women

Introduction: L-Arginine supplementation increases plasma levels of nitric oxide (NO) metabolites, an important mediator of peripheral dilatation. Therefore, L-Arginine supplementation can improve the duration and magnitude of post-exercise hypotension. Objectives: This study investigated the effects of L-Arginine supplementation on post-exercise hypotension, femoral artery area and heart rate variability in elderly women. Methods: Twenty prehypertensive and hypertensive adult female participants were divided (in a random and balanced manner) into two groups (placebo and L-arginine). The participants ingested eight grams of inert substance (placebo group) or eight grams of L-Arginine (L-arginine group), dissolved in water, 90 min prior to the experimental session. The experimental session consisted of an isokinetic maximal strength test. Blood pressure was measured using an oscillometric device (Omron MX3 Plus, Bannockburn, US) every 10 minutes for 60 minutes after the experimental session. Femoral artery area (ultrasound) and heart rate variability were also analyzed. Data underwent repeated measures (ANOVA) analysis and respective assumptions. Results: L-Arginine supplementation associated with exercise produced a significant decrease in systolic blood pressure [placebo vs L-Arginine] (p <0.05) at the “half-life” time point (90 minutes after supplementation) (141±12 vs 130±11 mmHg) and 40 min. (146±13 vs 127±13 mmHg), 50 min. (145±20 vs 127±15 mmHg) and 60 min. (147±19 vs 129±14mmHg) post-exercise. No significant differences were identified in femoral artery area and heart rate variability. Conclusion: Acute L-Arginine supplementation can increase post-exercise hypotension effects in elderly women. Additionally, acute L-Arginine supplementation is not related to either femoral artery area or heart rate variability responses. Level of evidence I; Randomized clinical trial.