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/m(2) 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.