The Association between Obesity, Blood Pressure Variability, and Right Ventricular Function and Mechanics in Hypertensive Patients

Abstract

Background The purpose of this investigation was to evaluate the association between blood pressure (BP) variability and right ventricular (RV) mechanical function in normal-weight, overweight, and obese untreated patients with hypertension. Methods This retrospective cross-sectional study included 127 untreated subjects with hypertension who underwent 24-hour ambulatory BP monitoring and complete two-dimensional and three-dimensional echocardiographic examination. All participants were divided into three groups according to body mass index (BMI): normal-weight patients (BMI < 25 kg/m2), overweight patients (25 ≤ BMI < 30 kg/m2), and obese patients (BMI ≥ 30 kg/m2). Results Daytime, nighttime, and 24-hour BP variability parameters were higher in overweight and obese subjects with hypertension than in lean subjects. Two-dimensional RV longitudinal strain and systolic strain rate were significantly lower in obese patients with hypertension than in normal-weight patients (−24.1 ± 3% vs −23.3 ± 3.2% vs −21.7 ± 3.3%, P = .004). Three-dimensional echocardiographic RV volumes indexed to body surface area were lower in lean and overweight subjects than in obese participants with hypertension (mean RV end-diastolic volume index, 65 ± 6 vs 67 ± 7 vs 71 ± 8 mL/m2, P = .001), while three-dimensional RV ejection fraction decreased in the same direction (60 ± 4% vs 58 ± 3% vs 57 ± 3%, P < .001). Nighttime BP variability indices, more than daytime BP variability parameters, correlated with two-dimensional RV global longitudinal strain and three-dimensional echocardiographic RV volumes. Conclusions BP variability and RV structure, function, and mechanics are significantly affected by obesity in patients with untreated hypertension. BP variability is significantly associated with RV remodeling in patients with hypertension. © 2016 American Society of Echocardiography