Effects of resveratrol supplementation on nitric oxide-mediated vascular outcomes in hypertension: A systematic review.

Hypertension is associated with endothelial dysfunction and decreased nitric oxide (NO). It has been proposed that decreasing oxidative stress may help regulate blood pressure by increasing NO concentration. Therefore, the purpose of this systematic review was to determine whether the antioxidant resveratrol effects NO-mediated vascular outcomes in hypertension. A comprehensive literature search of PubMed and EBSCOhost databases was conducted using the terms: "resveratrol" and "nitric oxide or NO" and "hypertension or high blood pressure." Searches were not restricted for year of publication or study design but limited to full-text studies from scholarly, peer-reviewed journals. Ten animal studies published between 2005 and 2017 were identified. Human studies did not meet criteria and were not included. Articles were critically assessed using the Academy of Nutrition and Dietetics' Evidence Analysis Library Quality Criteria Worksheet. All studies evaluated resveratrol supplementation and at least one NO outcome measure including: circulating NO metabolites, endothelial nitric oxide synthase (eNOS) expression, eNOS phosphorylation, and eNOS uncoupling. All but one study assessed blood pressure. Nine of ten studies reported positive significant results of resveratrol supplementation on NO outcomes, and in all but one study, this was seen concomitantly with decreases in blood pressure. Resveratrol supplementation shows promise for improving NO-mediated vascular outcomes and improving blood pressure. Translation to human studies is warranted, with dose of resveratrol considered, as the human equivalency doses are not consistent amongst animal studies. Additionally, a standard battery of tests examining NO-mediated vascular outcomes is needed to ensure generalizability among studies to determine dose-duration effects.

Implications of face mask use on body composition assessment by air-displacement plethysmography.

BACKGROUND & AIMS: The BOD POD (COSMED USA Inc., Concord, CA) is a common instrument used to assess body composition by employing air displacement plethysmography and whole-body densitometry to determine body volume. This instrument requires isothermal conditions during testing; therefore, the introduction of outside isothermal air can impact testing results. With the COVID-19 pandemic introducing face mask mandates, it is unknown whether the use of a face mask during BOD POD testing may lead to erroneous measurement by introducing isothermal air. Thus, the purpose of this cross-sectional study was to investigate the impact of wearing a surgical face mask compared to not wearing a surgical face mask on body composition assessment among adults. METHODS: During testing, female subjects were required to wear a swimsuit or form-fitting lycra shorts and a sports bra and male subjects were required to wear form-fitting lycra shorts. American Society for Testing and Materials (ASTM) level one surgical face masks (bacterial and particulate filtration efficiency of 95%) and standard swim caps were provided by researchers. Variables of interest included percent body fat, body fat, percent lean body mass, and lean body mass. Participants (n = 33) completed one test wearing a mask and one test without a mask back-to-back with conditions held constant. Dependent-sample sign tests, Bland-Altman Plots, and Passing-Bablok regression analyses were used to test mask-on versus mask-off differences and agreement between variables of interest. RESULTS: There were no significant median differences in any body composition results between face mask use and non-face mask use using dependent-sample sign tests. Bland-Altman Plots demonstrated acceptable agreement between mask usage and non-mask usage. No significant differences were seen in the slopes of the variables using Passing-Bablok regression. CONCLUSIONS: Results suggest that wearing a face mask does not appreciably impact body composition results. Therefore, ASTM level 1 disposable surgical face mask does not introduce a significant amount of isothermal air during BOD POD testing.