Association between waist-to-height ratio and endothelial dysfunction in patients with morbidity ― A report from the FMD-J study

Background: Waist circumference (WC), waist-to-height ratio (WHtR) and body mass index (BMI) are known as easy anthropometric markers of abnormal obesity and screening tools for predicting cardiovascular outcomes, but which indices are best is unclear. We therefore investigated the superiority and association between each index and low flow-mediated dilatation (FMD) as a surrogate marker for cardiovascular outcomes in patients with morbidity in a large Japanese prospective cohort. Methods and Results: A total of 1,645 Japanese patients who had coronary artery disease and hypertension or diabetes mellitus were enrolled, and 1,087 of them were analyzed. The high-WHtR group (≥0.5) showed greater morbidity and increased inflammation in association with atherosclerosis compared with the low-WHtR group. High WHtR and advanced age were identified as predictors of low FMD (odds ratio (OR) 1.39, 95% confidence interval (CI) 1.02–1.88, P=0.037 and OR 1.55, 95% CI 1.19–2.01, P=0.001, respectively). However, WC was not associated with that risk in either sex (male: OR 1.37, 95% CI 0.97–1.93, P=0.076; female: OR 1.08, 95% CI 0.68–1.73, P=0.74), and no association was evident between high BMI and low FMD (OR 0.92, 95% CI 0.71–1.19, P=0.54). Conclusions: WHtR offers a superior predictor of decreased FMD than other anthropometric indices, and progression of arteriosclerosis might be detected more sensitively. Further study is needed to investigate the relationship between cardiovascular mortality and WHtR.