Association between 24-hour diastolic blood pressure and renal function in patients receiving treatment for essential hypertension

OBJECTIVES: To evaluate the association between diastolic blood pressure (BP), measured by 24-hour ambulatory blood pressure monitoring (ABPM) and renal function in patients receiving treatment for essential hypertension. METHODS: In this cross-sectional study, ABPM, transthoracic echocardiography, estimated glomerular filtration rate (eGFR) on the basis of serum cystatin C (eGFRcyst) and the renal resistive index (RRI) were measured in patients with essential hypertension. RESULTS: The cohort consisted of 105 patients (39 men, 66 women), with a mean ± SD age of 58 ± 12 years who had been receiving treatment for 11 ± 8 years. 24-hour diastolic BP significantly positively correlated with eGFRcyst and negatively correlated with RRI. No correlation was observed with 24-hour systolic BP values. 24-hour diastolic BP values ≤70 mmHg were associated with eGFRcyst ≤60 ml/min/1.73 m(2) (i.e., decreased GFR). CONCLUSION: 24-hour diastolic BP values were significantly associated with markers of kidney function in patients receiving treatment for essential hypertension and values ≤70 mmHg may be associated with subnormal eGFRcyst.