Hydration status and blood pressure variability in primary hypertensive patients

Abstract

BackgroundIncreased blood pressure variability (BPV) is associated with higher cardiovascular risk. The association between BPV and fluid status in hypertensive patients has not been investigated so far. The aim of the present study was to determine the contribution of fluid balance to BPV and impact on endothelial and cardiac functions among primary hypertensive patients. MethodsThis is a prospective interventional study conducted in primary hypertensive patients with one-year follow-up. Volume status measurements by a body composition monitor, ambulatory blood pressure (BP) monitoring, echocardiographic and carotid intima-media thickness (CIMT) measurements were performed at enrollment and at twelfth. Patients in one of the two groups were kept negative hydrated during trial with diuretic treatment. Patients in other group were positively hydrated (hypervolemic) at enrollment, antihypertensive drugs other than diuretics (vasodilator agents) were added or intensified according to the BP monitoring. Average real variability (ARV) index was used for establishing the prognostic significance of BPV. ResultsThe study population consisted of 50 patients with a mean age of 54.5±8.8 years. At the end of one-year follow-up, patients in negative hydrated group were found to have significantly lower BP, CIMT, left ventricle mass index (LVMI) and systolic and diastolic ARV. More weight gain and higher systolic BP were major risk factors of high systolic ARV. Patients who have improvement in CIMT and LVMI were considered as target organ damage (TOD) recovery present. In negatively hydrated group, TOD significantly reduced during trial. In patients who have TOD recovery, BPV significantly more reduced like systolic and diastolic BP. Significant risk factors associated with the presence of TOD were 24h systolic BP and daytime and night time diastolic ARV and night time diastolic BP. ConclusionAddition of diuretic to established treatment or intensified diuretic treatment and keeping patients in negative hydration status resulted in reduction in BPV at twelfth month of follow-up. More weight gain and higher systolic BP are major risk factors of high systolic ARV, but not hypervolemia. BPV, especially diastolic ARV, was significantly associated with TOD.