Abstract 15257: Nighttime Hemodynamics and Aortic Stiffness have a Powerful Additive Predictive Value on the Development of Microalbuminuria in Hypertension: a 6-year Follow-up Study
Introduction: Arterial stiffness and nighttime blood pressure are associated with target organ damage and they convey increased cardiovascular risk.
Hypothesis: To assess whether aortic stiffening defined by carotid-femoral pulse wave velocity (PWV) has either additive or synergistic effect with ambulatory BP load in new-onset microalbuminuria during follow-up.
Methods: 163 white hypertensive non-diabetic patients (52±10 years, 98 men, 59 smokers, body mass index=28.8±5.4Kg/m2) were prospectively studied for 6 years. All patients underwent 24-hour ambulatory monitoring and PWV measurement with Complior SP. Metabolic profile, estimated creatinine clearance (eGFR) and echocardiographic measurements were performed at baseline and last outpatient clinic visit (follow-up: 4.5±0.89 years). Microalbuminuria was defined as ACR between either 20 or 30 (men and women respectively) and 300mg. All subjects were under optimal antihypertensive therapy complemented by vasoactive drugs where appropriate. The administered medication during the last 6-month period before last visit consisted of: renin-angiotensin system inhibitors RAASI (49%), diuretics (25%), calcium-channel blockers (20%), beta-blockers (13%), statins (16%) and antiplatelet agents (18%).
Results: Baseline nighttime systolic and diastolic BP were 121±13 and 73±9mmHg, while the incidence of microalbuminuria was 13.5% (n=22). Between baseline and last visit there was a decrease in BMI by 1.9±4.1Kgr/m2, while PWV was increased by 1.83±1.37m/s (7.9±1.5 vs. 9.6±1.5m/s). During follow-up, 24h systolic and diastolic BP were decreased by 12.7±9.1 and 8.2±6.2mmHg (130±12 vs.122±12 and 80±9 vs. 75±8mmHg) respectively. In Cox regression models after adjustment for confounders, independent predictors (HR [95% CI]) of microalbuminuria were: baseline nighttime systolic BP, 1.034 [1.001–1.068], p=0.046, baseline PWV, 1.317 [1.048–1.654], p=0.018, and the interaction term of nighttime systolic BP × baseline PWV, 1.003 [1.001–1.004], p<0.001.
Conclusions: Baseline nighttime systolic BP and PWV have an additive effect on the incidence of microalbuminuria suggesting that integrated stiffening measures may predict kidney damage in the early course of hypertension.
- © 2010 by American Heart Association, Inc.