Reactive hyperemia index can screen endothelial dysfunction in obese subjects with non-alcoholic fatty liver disease

Background and Aims: Reactive hyperemia-peripheral arterial tonometry (RH-PAT) has been developed to detect early stage vascular dysfunction. Recent studies have suggested that Reactive hyperemia index (RHI) assessed using RH-PAT could be used to predict the mortality of subjects with high risks for cardiovascular events. On the other hand, carotid intima-media thickness (IMT), pulse wave velocity (PWV), and/or cardio-ankle vascular index (CAVI) have been used as screening tools for vascular disorders. Since obesity and metabolic syndrome are the risk factors for cardiovascular events, we aimed to examine the association of RHI, CAVI, and carotid artery plaque scores with the body mass index (BMI). Methods: The participants of this study were 39 Japanese subjects who were admitted at the Department of Liver Disease of Shimane University Hospital between August and December 2016 (mean age, 62 years). RH-PAT findings, CAVI, and carotid IMT were evaluated, and their associations with BMI were analyzed. Carotid IMT and plaque score (PS) were evaluated by ultrasonography following the standard protocol. A score of less than 1.67 was defined as a low RHI. Results: The PS was associated with age (r=0.511, p<0.0001) but not with BMI. Interestingly, CAVI had a positive association with age (r=0.706, p<0.0001) and an inverse association with BMI (r=-0.511, p<0.0001). In contrast, RHI had no significant association with age and BMI. Among 14 patients with non-alcoholic steatohepatitis (NASH) or non-alcoholic fatty liver disease (NAFLD) with BMI! 25, only one patient had high CAVI (>9.0) whereas 6 patients had low RHI. Conclusions: NASH/NAFLD subjects, especially those with obesity, are good candidates for RH-PAT examination to detect early stage of vascular failure.