Effect of L-Arginine and Pycnogenol on Light to Moderate Hypertension and Endothelial Function

Effect of a Dietary Supplement on Endothelial Function in Volunteers With Light to Moderate Hypertension - a Randomised, Double-blind, Placebo Controlled Cross-over Study

The effect of a combination product (Verum ) with L-arginine, Pycnogenol, vitamin K2, R-(+)-alpha-lipoic acid and vitamins B6, B12 and folic acid is investigated in a double blind placebo-controlled cross-over study. Volunteers with hypertension and hyperhomocysteinemia are randomly assigned to the dietary supplement or placebo.

25 patients were included in the trial. Intervention period was 4 weeks with 2 months wash out phase. The screening visit of all volunteers before study start included volunteer information, signature of informed consent, anamnesis, medical history, ECG and blood routine analysis. Efficacy parameters were measured at visit 1, 2, 3, and 4. Endothelial function and postprandial endothelial Reaction was tested using EndoPAT (validated diagnosis tool). Blood pressure was measured by volunteers over a period of 7 days before each visit. As additional parameters homocysteine and ADMA (assymmetric dimethyl arginine) were determed. For safety evaluation AEs (Adverse Events), CC (compliance control), tolerability, blood routine parameters and vital signs were assessed.

2400 mg L-arginine, 80 mg Pycnogenol, 45µg vitamine K2, 10 mg R (+) alpha lipoic acid, 8 mg vitamine B6, 500 µg vitamine B12, and 600 mg folic acid.

Change in Endothelial Function Between the Visit at Start of Supplementation Phase and the Visit on the Final Day of the 4 Week Supplementation Phase (Delta "lnRHI")

Endothelial function was determined with the EndoPAT™ method (non-invasive Peripheral Aterial Tonometry) using a reactive hyperemia procedure. The outcome measure is the change in endothelial function between the visit at start of the supplementation phase and the visit on the final day of the 4 week supplementation phase. The endothelial function is determined as the natural log of the Reactive Hyperemia Index ("lnRHI") which is the post-to-pre occlusion peripheral arterial tonometry signal ratio in the occluded side, relative to the same ratio in the control side, corrected for baseline vascular tone of the occluded side. Normal lnRHI > 0.51, Abnormal lnRHI < 0.51

The mean of daily systolic and diastolic blood pressure measured daily at the last 7 days of the 4 week intervention period. Measurements were performed by subjects at home and were taken on the left arm, after at least 10 minutes of rest, in a sitting position.

Homocystein level in µmol/l was determined on the final day of the 4 week intervention period. The first supplementation period started at visit one and lasted for 4 weeks. It was followed by a wash out phase of 8 weeks and subsequently by a second supplementation phase of 4 weeks (cross-over design)

Asymmetric Dimethyl Arginine (ADMA) Level Determined on the Final Day of the 4 Week Intervention Period.

ADMA (asymmetric dimethyl arginine) was determined on the final day of the 4 week intervention period. Samples were analyzed batch wise using an enzymatic test

Glycated hemoglobin (HbA1c) as percentage of total hemoglobin was determined on the final day of the 4 week intervention period.

Change in Prothrombin Time Between the Visit at Start of Supplementation Phase and the Visit on the Final Day of the 4 Week Supplementation Phase

Prothrombin Time was assessed at the visit at start of the supplementation phase and the visit at the end of the 4 week supplementation phase. Blood coagulability is expressed in units of Quick value. In this case, the measured prothrombin time is expressed in relation to the coagulation time of a healthy person. The value obtained is the "percentage of the standard Quick value". In a person not receiving oral anticoagulation the "normal" Quick value is between 70 and 100%. The longer the patient's coagulation time, the lower the Quick value

Inclusion Criteria: borderline blood pressure (systolic 130-149) homocystein level >10µmol/l Exclusion Criteria: e.g. BMI <20kg/m2 and >32kg/m2 use of antihypertensives, anticoagulants, and statins cardiovascular diseases e.g. stroke, myocardial infarction use of L-arginine and other dietary supplements

Reule CA, Goyvaerts B, Schoen C. Effects of an L-arginine-based multi ingredient product on endothelial function in subjects with mild to moderate hypertension and hyperhomocysteinemia - a randomized, double-blind, placebo-controlled, cross-over trial. BMC Complement Altern Med. 2017 Feb 2;17(1):92. doi: 10.1186/s12906-017-1603-9.