Background: Exercise training and L-arginine are believed to have a major role in managing the hypertension and also their combination may cause further improvement in blood pressure. Therefore, the present study aimed to determine the effect of combined training with or without L-arginine ingestion on the circulation of adropin, VEGFR-2, and nitric oxide (NO) in postmenopausal women with hypertension.
Methods: The present study was a randomized double-blind placebo-L-arginine-controlled trial registered in Iranian Registry of Clinical Trials with the code of IRCT20210627051723N1. This work was conducted in the summer and autumn of 2021. We recruited 48 post-menopausal women with hypertension and assigned them randomly (choosing random numbers by participants) in four equal groups, namely training+Larginine (TL), training (T), L-arginine (L), placebo (P) groups. The study intervention (combined training, L-arginine, or both) continued for eight weeks. Before starting and after completing the intervention period, blood samples were collected and the levels of variables was measured via Elisa method. The SPSS version 24 and analysis of covariance test (ANCOVA), along with bonferroni post-hoc test were utilized for data analysis.
Results: The obtained results represented a significant increase in the serum levels of adropin and VEGFR-2 in T and TL groups compared to those in P and L groups (p <0.001). Moreover, Nitric Oxide significantly increased in L (P=0.003), T (p <0.001), and TL (p <0.001) groups compared to P group. In addition, systolic blood pressure decreased significantly in T, L, and TL groups compared to that in P group (p <0.001), and in TL group compared to L (p <0.001) and T (P=0.048) groups. On the other hand, we observed a significant decrease in diastolic blood pressure in L (P=0.002), T (p <0.001), and TL (p <0.001) groups compared to that in P group; the same trend was seen in TL group compared to L group (P=0.003).
Conclusion: Combined training with or without L-arginine ingestion has positive effects by decreasing blood pressure, which was partly exerted by upregulation of adropin and VEGFR-2. Moreover, L-arginine supplementation was found to be associated with an increase in combined training effect in decreasing blood pressure.