6. Brachial-Ankle Pulse Wave Velocity and Chronic Kidney Disease as a Prognostic Impact in Hypertension

Background Many reports have shown that brachial-ankle pulse wave velocity (baPWV) has an effect on evaluation of atherosclerotic change and would be one of the prognostic factors for hypertension (HT). It has been reported that chronic kidney disease (CKD) would influence the prognosis of HT or diabetes mellitus. Therefore we examined how baPWV and CKD effects the incidence of cardiovascular disease (CVD) by the cohort study in hypertensive patients using the AT-form which we can measure PWV easily. Methods This study included 380 patients with essential HT (male/female 206/174, mean age 60.9 ± 12.1, mean follow period 41months) whose baPWV could be measured from October, 2000 to December, 2004. We set up stroke (n = 19) and CVD (n = 18) as a primary end point by the questionnaire. We estimated CKD as lower glomerular filtration rate (GFR) with MDRD formula and proteinuria. We produced quartile groups according to the baseline measurements of baPWV or the presence of CKD and assessed the prognostic impact on stroke and CVD. Results There was a significant negative correlation between baPWV and GFR (P< 0.0001, r = 0.256). The baPWV with CKD (n = 287; 1654 ± 331 cm/sec) was significantly higher than that without CKD (n = 93; 1771 ± 333 cm/sec). By Kaplan-Meier analysis, highest quartile of baPWV was the prognostic impact of stroke (p = 0.0062) but not CKD (p = 0.3947). The incidence of stroke and CVD did not correlated with baPWV (p = 0.0912) or CKD (p = 0.1381). When we classified into 4 groups; high PWV + CKD, high PWV+non CKD, low PWV + CKD and low PWV+non CKD, high PWV + CKD showed significantly higher prognostic impact of stroke and CVD. Conclusion Our study indicated that higher level of baPWV and the existence of CKD might be a risk factor of stroke and CVD in hypertension.