PS-BPC04-2: ASSOCIATION OF SHORT-TERM BLOOD PRESSURE VARIABILITY AND MICROALBUMINURIA IN ESSENTIAL HYPERTENSION: DIFFERENCES ACCORDING TO CLASSIFICATIONS OF BLOOD PRESSURE ABSOLUTE VALUE

Abstract

Objective: Increased short-term blood pressure (BP) variability has been highlighted as a novel risk for cardiovascular diseases. The influence of short-term BP variability on cardiovascular mortality is also accelerated together with increase in BP. In essential hypertension, short-term BP variability is independently associated with early renal abnormalities. In this study, the associations of short-term BP variability with microalbuminuria were analyzed according to classifications of BP absolute value in essential hypertensive patients. Design and method: In 222 untreated essential hypertensive patients (127 males, average age 55 ± 11 years) without chronic kidney disease (urinary albumin excretion less than 300 mg/g of creatinine and estimated glomerular filtration rate 60 mL/min/1.73m2 or more), ambulatory BP monitoring was performed to estimate BP and the standard deviation of systolic BP (SBP-SD) during 24 hours. The 24-hour urine collection was also done to evaluate urinary albumin excretion. According to 24-hour BP level, patients were divided into 4 groups: 33 patients with BP < 130/80 mmHg (N), 71 patients with BP of 130–149/80–89 mmHg (G1), 84 patients with BP of 150–169/90–99 mmHg (G2) and 34 patients with BP 170/100 mmHg (G3). Results: 24-hour systolic BP correlated positively with urinary albumin excretion in G1, G2 and G3 groups (r = 0.25 in G1 group; r = 0.22 in G2 group; r = 0.30 in G3 group, p < 0.05, respectively), whereas there was no relation between them in N group. SBP-SD correlated positively with UAE in both G2 and G3 group (r = 0.20 in G2 group; r = 0.30 in G3 group, p < 0.05, respectively), but did not so in either N or G1 group. Thus, the correlation between SBP-SD and urinary albumin excretion was confined to patients with 24-hour BP ≧ 150/90 mmHg. Furthermore, in patients with 24-hour BP ≧ 150/90 mmHg, multiple regression analysis revealed that SBP-SD was an independent determinant for urinary albumin excretion together with 24-hour systolic BP. Conclusions: These data indicate in essential hypertensive patients, that the risk of increased short-term BP variability for microalbuminuria could be potentiated along with the elevation in BP absolute value.