Association of non-alcoholic fatty liver disease with impaired endothelial function by flow-mediated dilation: A meta-analysis

Aim Endothelial dysfunction was observed in patients with non‐alcoholic fatty liver disease. The aim of the present study was to evaluate the extent of endothelial function impairment in patients with non‐alcoholic fatty liver disease. Methods We systematically searched through the PubMed, Embase, China National Knowledge Infrastructure and Wanfang databases for studies dated up to January 2015. All observational studies that compared endothelial function between non‐alcoholic fatty liver disease patients and healthy controls were included. Endothelial function was measured by brachial artery flow‐mediated dilation and nitrate‐induced dilatation techniques. Results Eleven observational studies were identified. Meta‐analysis indicated that non‐alcoholic fatty liver disease patients were associated with a reduction in brachial artery flow‐mediated dilation (weighted mean difference, –4.82%; 95% confidence interval [CI], –5.63 to –4.00) compared with the healthy controls. Subgroup analysis indicated that the patients with non‐alcoholic steatohepatitis or a body mass index of more than 30 kg/m2 appeared to have a greater reduction in their flow‐mediated dilation. However, no significant differences were observed in the nitrate‐induced dilation (weighted mean difference, –0.4%; 95% confidence interval, –2.19 to 1.39). Conclusion Non‐alcoholic fatty liver disease is associated with a greater risk of endothelial dysfunction as indicated by the decreased brachial artery flow‐mediated dilation. Assessment of endothelial function may be recommended to identify subclinical atherosclerosis and to create subgroups of non‐alcoholic fatty liver disease patients who are at higher risk of future cardiovascular events.