Antioxidant Cocktail Acutely Restores Vascular Function After a High Sodium Meal in Males, but not Females

Endothelial dysfunction is a primary event in the development of atherosclerosis, a leading cause of cardiovascular disease (CVD). Furthermore, increased arterial stiffness is an independent risk factor for CVD. High dietary sodium intake has been shown to impair vascular function independent of blood pressure (BP) in young, healthy adults with greater impairments seen in males. A proposed mechanism of sodium‐induced vascular dysfunction is through an increase in oxidative stress. Therefore, the objective of this study was to investigate the acute effects of a high sodium meal and antioxidant cocktail on measures of vascular function and arterial stiffness. We recruited healthy, non‐hypertensive males and females 18–45 years old. Subjects completed two study visits separated by at least 48 hours and females were tested in the early follicular phase of the menstrual cycle. Vascular function was assessed using brachial artery flow‐mediated dilation (FMD) and arterial stiffness was measured by carotid‐femoral pulse wave velocity (PWV). Participants ingested either two doses of an antioxidant cocktail (AO; each capsule contained 500 mg vitamin C, 300 IU vitamin E, and 300 mg alpha‐lipoic acid) or a placebo (PLA; cellulose) followed by a high sodium meal (1500 mg Na + ). BP and PWV were measured at baseline (BSL) and 30, 60, 90, and 120 minutes after meal consumption, whereas FMD at BSL, 60, and 120 min. Thirty‐four participants (14M, 20F; 23 ± 1 years; BMI 23 ± 0.4 kg/m 2 ; systolic BP 112 ± 1 mmHg, diastolic BP 66 ± 1 mmHg) completed the study. FMD was not different between visits when all subjects were combined (AO: BSL: 6.6 ± 0.5, 60min: 6.9 ± 0.6, 120min: 6.9 ± 0.6%; PLA BSL: 7.0 ± 0.6, 60min: 6.6 ± 0.7, 120min: 6.7 ± 0.5%; P>0.05). However, FMD was greater at 120min in AO compared to PLA in males (120min: AO: 6.6 ± 0.8%; PLA: 5.2 ± 0.6%; P<0.05) but not in females (120min: AO: 7.2 ± 0.9%; PLA: 7.7 ± 0.6%; P>0.05). Peak shear stimulus for dilation was reduced post‐meal compared to BSL in both visits in males (BSL: 758 ± 59, 60min: 657 ± 42 s −1 ; P<0.05) but not in females (P>0.05). Mean arterial pressure (MAP) was higher at 120 min compared to 60 and 90 min in both visits among all subjects (BSL: 80 ± 1, 30min: 80 ± 1, 60min: 79 ± 1, 90min: 78 ± 1, 120min: 80 ± 1mmHg, P<0.05), with no differences seen among sexes (P>0.05). PWV adjusted for MAP decreased from 30 to 60min and recovered from 60 to 120min for all subjects in both visits (AO: BSL: 5.4 ± 0.1, 30min: 5.4 ± 0.1, 60min: 5.3 ± 0.1, 120min: 5.5 ± 0.1 m/s; PLA: BSL: 5.2 ± 0.1, 30min: 5.3 ± 0.1, 60min: 5.1 ± 0.1, 120min: 5.3 ± 0.1 m/s; P<0.05) demonstrating no effect of the AO and a similar effect was seen in males alone (BSL: 5.6 ± 0.1, 30min: 5.7 ± 0.1, 60min: 5.5 ± 0.1 m/s; P <0.05), but remained unchanged in females (P>0.05). There were no differences in MAP, FMD or PWV at BSL between the visits. In conclusion, vascular function was reduced following acute consumption of a high sodium meal in young, healthy males which was not observed in females. While the AO had no effect on arterial stiffness, these data suggest that AO may offer benefit to sodium‐induced vascular function impairment in males. Support or Funding Information KAAP17S526 This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .