Association between urinary 8-hydroxydeoxyguanosine, an indicator of oxidative stress, and the cardio-ankle vascular index in hypertensive patients

Abstract

Aims: Oxidative stress has been recently postulated to be an important factor in the pathogenesis and development of arteriosclerosis. Although urinary 8-hydroxydeoxyguanosine (8-OHdG) is clinically used as a marker of oxidative stress, its usefulness in diagnosing arteriosclerosis has not been fully examined. This study aimed to evaluate the association between urinary 8-OHdG and the cardioankle vascular index (CAVI) as a marker of arterial stiffness in hypertensive patients. Methods: We enrolled 100 hypertensive patients (70±10 years) who had been taking antihypertensive medications for at least one year. Urinary 8-OHdG levels were measured by an immunochromatographic assay (ICR-001; Selista Inc., Tokyo, Japan). CAVIs were measured at the same visit. Results: Urinary 8-OHdG was correlated with smoking habits (r =0.382, p<0.001) and CAVIs (r =0.223, p= 0.026). Multiple linear regression analysis revealed two independent determinants of urinary 8-OHdG: smoking habits (β=0.501, p<0.001) and CAVI (β=0.325, p= 0.001). In addition, CAVIs were correlated with age (r =0.600, p<0.001), BMI (r =-0.348, p<0.001), systolic blood pressure (r =0.343, p<0.001), pulse pressure (r =0.358, p<0.001), serum creatinine level (r =0.408, p<0.001), urinary 8-OHdG level (r =0.223, p=0.026), and diabetes (r =0.210, p=0.036). Multiple linear regression analysis revealed two independent determinants of CAVI: age (β=0.568, p<0.001) and 8-OHdG (β=0.357, p<0.001). Conclusion: Elevated CAVI is independently associated with an elevated urinary 8-OHdG level in hypertensive patients.