Association of E/E′ and NT-proBNP with Renal Function in Patients with Essential Hypertension

Objectives To evaluate the association of left ventricular (LV) diastolic function and N-terminal pro-brain natriuretic peptide (NT-proBNP) with renal function in essential hypertension. Methods LV diastolic function was estimated by the ratio of early diastolic velocities (E) from transmitral inflow to early diastolic velocities (E′) of tissue Doppler at mitral annulus (septal corner); NT-proBNP was measured in 207 hypertensive patients (mean age 56±14 years). The subjects were classified into 3 groups: E/E′≤10 group (n = 48), 1015 group (n = 50). The renal function was estimated by glomerular filtration rate (GFR) with 99m Tc-DTPA. GFR from 30 to 59 ml/min/1.73 m 2 was defined as Stage 3 chronic kidney disease (CKD). GFR was also estimated using the modified MDRD equation. Albuminuria was defined by urinary albumin/creatinine ratio (UACR). Results GFR was lower and UACR was higher in E/E′ >15 group than in 10< E/E′ ≤15 group or E/E′ ≤10 group ( p <0.0001), GFR was significantly negative and UACR was positive correlated with E/E′ and NT-proBNP ( p <0.0001). In multivariate stepwise linear analysis, GFR had significant correlation with age ( p  = 0.001), gender ( p  = 0.003), E/E′ ( p  = 0.03), lgNT-proBNP (p = 0.001) and lgUACR ( p  = 0.01), while eGFR had no significant correlation with E/E′ or lgNT-proBNP. Multivariate logistic regression analysis, adjusted for potential confounding factors, showed that participants in E/E′>15 group were more likely to have Stage 3 CKD compared with those in E/E′≤10 group with an adjusted odds ratio of 8.31 ( p  = 0.0036). Conclusions LV diastolic function, assessed with E/E′ and NT-proBNP is associated with renal function in essential hypertension.