Background
Endothelial dysfunction is a predictive risk factor for the development of atherosclerosis and is assessed by flow-mediated dilation (FMD). Although it is known that nitric oxide-dependent endothelial dysfunction occurs after consuming a high-fat meal, the magnitude of the effect and the factors that affect the response are unquantified.
Objectives
To conduct a systematic review and meta-analysis exploring the quantitative effect of a single high-fat meal on endothelial function and determine the factors that modify the FMD response.
Design
Six databases were systematically searched for original research published up to January 2022. Eligible studies measured fasting and postprandial FMD following consumption of a high-fat meal. Meta-regression was used to analyze the effect of moderator variables. The protocol was pre-registered in the Prospero database (ID# CRD42020187244).
Results
There were 131 studies included of which 90 were suitable for quantitative meta-analysis. A high-fat meal challenge transiently caused endothelial dysfunction, decreasing postprandial FMD at 2-hours: -1.02 percentage points (pp) (95% CI: [-1.34, -0.70], P < 0.01, I2 = 93.3%), 3-hours: -1.04 pp ([-1.48, -0.59], P < 0.001, I2 = 84.5%), and 4-hours: -1.19 pp ([-1.53, -0.84], P < 0.01, I2 = 94.6%). Younger, healthy-weight participants exhibited a greater postprandial reduction in FMD% than older, heavier, at-risk groups after a high-fat meal (P < 0.05). Percent fat of the meals was inversely associated with the magnitude of postprandial change in FMD at 3-hours (P < 0.01).
Conclusion
A single high-fat meal adversely impacts endothelial function, with the magnitude of the impact on postprandial FMD moderated by fasting FMD, participant age, body mass index, and fat content of the meal. Recommendations are made to standardize the design of future postprandial FMD studies and optimize interpretation of results, as high-fat meals are commonly used in clinical studies as a challenge to assess endothelial function and therapeutics.