A single, high-fat meal adversely affects postprandial endothelial function: a systematic review and meta-analysis

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 NO-dependent endothelial dysfunction occurs after consuming a high-fat meal, the magnitude of the effect and the factors that affect the response are unquantified. We conducted a systematic review and meta-analysis exploring the quantitative effects of a single high-fat meal on endothelial function and determined the factors that modify the FMD response. 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. 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 to –0.70 pp; P < 0.01; I2 = 93.3%], 3 hours [–1.04 pp; 95% CI: –1.48 to –0.59 pp; P < 0.001; I2 = 84.5%], and 4 hours [–1.19 pp; 95% CI: –1.53 to –0.84 pp; P < 0.01; I2 = 94.6%]. Younger, healthy-weight participants exhibited a greater postprandial reduction in the FMD percentage change than older, heavier, at-risk groups after a high-fat meal (P < 0.05). The percentage of fat in the meals was inversely associated with the magnitude of postprandial changes in FMD at 3 hours (P < 0.01). A single, high-fat meal adversely impacts endothelial function, with the magnitude of the impact on postprandial FMD moderated by the fasting FMD, participant age, BMI, 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. This trial was registered at PROSPERO as CRD42020187244.