A Single Dosage of l-Arginine Oral Supplementation Induced Post-Aerobic Exercise Hypotension in Hypertensive Patients.

Lowering of peripheral vascular resistance is one of the primary processes involved in blood pressure decrease. Nitric oxide plays a significant role in this process and the availability of l-arginine is a crucial element in nitric oxide biosynthesis. Oral l-arginine supplementation may therefore be a potentiating element in post-exercise hypotension, mediated by its vasodilator action. Thus, the purpose of this study was to investigate if a single dose of l-arginine oral supplementation might impact the post-aerobic exercise blood pressure responses in treated hypertensive individuals. A double-blind, randomized, placebo-controlled crossover trial was conducted. The sample included male (4) and female (6) subjects [62 ± 10 years]. The participants were randomized to ingest one sachet containing 8 grams of l-arginine or placebo (corn starch) dissolved in water (100 ml). The substances were self-administered 120 min before the experimental or control session. The exercise was conducted on a treadmill and consisted of: a 5 min warm-up (50-65% HRreserve); 40 min of running/walking at 60-70% HRreserve; and a 5 min progressive cooldown. After the exercise sessions, blood pressure was measured every 10 min for 60 min. The l-arginine supplementation arm led to significant post-exercise systolic hypotension (mean post-exercise) in relation to rest period (117 ± 12 vs 125 ± 15 mmHg - p = 0.004 [l-arginine] and 121 ± 11 vs 125 ± 15 - p = 0.341 [placebo]). In addition, a systolic net effect of -6.9 ± 3.6 mmHg [p = 0.046] was identified for the mean post-exercise values. Therefore, this study showed that a single dosage of l-arginine oral supplementation induced post-aerobic exercise hypotension in hypertensive patients.

Acute citrulline oral supplementation induces greater post-exercise hypotension response in hypertensive than normotensive individuals / Suplementação oral aguda de citrulina induz maior resposta hipotensiva pós-exercício em indivíduos hipertensos do que normotensos

ABSTRACT Objective To investigate whether acute citrulline supplementation might influence post-exercise hypotension in normotensive and hypertensive individuals. Methods Following a randomized double-blind design, twenty normotensive (28±7 years, 74±17kg, 1.7±0.09m) and 20 hypertensive individuals (55±12 years, 76±15kg, 1.59±0.09m) were randomly assigned to one of the four experimental groups (Normotensive-Placebo; Normotensive-Citrulline; Hypertensive-Placebo; Hypertensive-Citrulline). The placebo groups ingested 6g of corn starch and the citrulline groups ingested 6g of citrulline dissolved in water. The participants performed 40 minutes of walking/running on a treadmill at 60-70% heart rate reserve. Blood pressure was measured immediately after a 60-min exercise session using an oscillometric device and 24-h ambulatory monitoring. Results The post-exercise hypotension was more pronounced in hypertensives and the Hypertensive-Citrulline group showed a consistent systolic blood pressure reduction during the laboratorial phase, which can be seen by looking at the mean of 60 minutes (-15.01mmHg vs -3.14mmHg [P=0.005]; -4.16mmHg [P=0.009]; -6.30mmHg [P=0.033] in comparison with the Normotensive-Placebo, Normotensive-Citrulline, and Hypertensive-Placebo groups, respectively). During ambulatory blood pressure monitoring, the Hypertensive-Citrulline group showed a significant reduction in systolic blood pressure (-21.05mmHg) in the awake period compared with the Normotensive-Citrulline group (-3.17mmHg [P=0.010]). Conclusion Acute citrulline oral supplementation can induce greater post-exercise hypotension response in hypertensive than normotensive individuals.

RESUMO Objetivo Investigar se a suplementação aguda de citrulina pode influenciar a hipotensão pós-exercício em indivíduos normotensos e hipertensos. Métodos Seguindo delineamento duplo-cego randomizado, vinte indivíduos normotensos (28±7 anos, 74±17kg, 1,7±0,09m) e 20 hipertensos (55±12 anos, 76±15kg, 1,59±0,09m) foram randomizados e distribuídos em um dos quatro grupos experimentais (Normotenso-Placebo; Normotenso-Citrulina; Hipertenso-Placebo; Hipertenso--Citrulina). Os grupos placebo ingeriram 6g de amido de milho e os grupos citrulina 6g de citrulina, dissolvidos em água. Os participantes realizaram 40 minutos de caminhada/corrida em esteira a uma intensidade entre 60-70% da frequência cardíaca de reserva. A pressão arterial foi aferida imediatamente após a sessão de exercício por 60 minutos usando um equipamento oscilométrico, e durante 24 horas por monitorização ambulatorial. Resultados A hipotensão pós-exercício foi mais pronunciada nos hipertensos e o grupo Hipertenso-Citrulina mostrou uma redução consistente da pressão arterial sistólica durante a fase laboratorial, o que pode ser visto pela média de 60 minutos (-5,01mmHg vs -3,14mmHg [P=0,005]; -4,16mmHg [P=0,009]; -6,30mmHg [P=0,033] em comparação com o Normotenso-Placebo, Normotenso-Citrulina e Hipertenso-Placebo, respectivamente). Durante a monitorização ambulatorial da pressão arterial, o Hipertenso-Citrulina demonstrou uma redução significativa na pressão arterial sistólica (-21,05mmHg) durante a vigília em comparação com o Normotenso-Citrulina (-3,17mmHg [P=0,010]). Conclusão A suplementação oral aguda de citrulina induz maior resposta hipotensiva pós-exercício em indivíduos hipertensos do que normotensos.