NPPB and essential hypertension: The purpose of this study was to evaluate whether LV diastolic function is correlated with renal function, and to determine the association of E/E′ and NT-proBNP with glomerular filtration rate (GFR) measured with technetium-99m-(99mTc) diethylenetriaminepentaacetic acid (DTPA) in essential hypertension.