Background: Recent studies have confirmed the essential and paramount role of the L-Citrulline on the nitric oxide regulation and the endothelial function improvement.
Materials and methods: In this cross-over clinical trial, thirty patients, diagnosed with coronary artery disease (CAD) and flow mediated dilation to nitroglycerin dependent vasodilation (FMD/NMD) ratio less than 1, were included. The patients were randomly divided into two groups of 15 patients and underwent treatment by L-Citrulline or placebo for 15 days, in 2 step protocol. The indicators of assessment in the current study were the ratio of the FMD/NMD and FMD value.
Results: In the current cross-over clinical trial, the mean of FMD to NMD ratio and mean FMD value of all patients before starting the protocol were 0.91 ± 0.08 and 4.04 ± 0.51 mm, respectively. The final results of study showed that following L-Citrulline administration, mean FMD to NMD ratio and mean FMD value were enhanced to: 1.03 ± 0.09 and 4.96 ± 0.72 mm, respectively, which were statistically significant (P<0.001 and P<0.001, respectively). However, following placebo administration, mean FMD to NMD ratio and mean FMD value were receded to: 0.92 ± 0.09 and 4.06 ± 0.22 mm, respectively, which were not statistically significant (P = 0.75 and P = 0.89, respectively). Moreover, the improvement of mean FMD to NMD ratio (0.12 ± 0.02) and mean FMD value (0.92 ± 0.16 mm), following L-Citrulline administration, were statistically significant in comparison with the change of mean FMD to NMD ratio (0.01 ± 0.002) and mean FMD value (0.02 ± 0.003), following placebo administration (P<0.001 and P<0.001, respectively).
Conclusion: L-Citrulline treatment can lead to improvement of the endothelial function in patients diagnosed with CAD which are assessed via FMD to NMD ratio FMD value enhancements.