Impaired exercise tolerance is associated with increased urine albumin excretion in the early stages of essential hypertension

Abstract

Our aim was to investigate the relationship between impaired exercise capacity and albumin excretion level in the setting of never treated essential hypertension. For this purpose, 338 consecutive essential hypertensives (52 ± 8.5 years, 227 males, office BP = 148.6/96.1 mmHg) performed a negative for myocardial ischemia, maximal treadmill exercise testing and were classified based on the gender specific median value of the amount of metabolic equivalents (METs) achieved (10.1 ml/kg/min for women and 11 ml/kg/min for men) as fit (n = 177) and unfit (n = 161). All the participants underwent 24-h ambulatory BP monitoring, complete echocardiographic study including left ventricular diastolic function evaluation and determination of albumin to creatinine ratio (ACR) on two non-consecutive morning spot urine samples. Unfit hypertensives compared to the fit ones were older by 4.5 years (p < 0.001) and had greater waist circumference by 4.5 cm (p < 0.001), body mass index by 1.3 kg/m(2) (p = 0.001), 24-h pulse pressure by 3.0 mmHg (p = 0.005), ACR levels by 12.6% (p = 0.003) and prevalence of microalbuminuria (19.5% vs 10.3%, p = 0.007) while the differences in diastolic function indices lost significance after adjustment for confounders. By applying stepwise multivariate linear regression analysis in order to identify the predictors of METs, it was revealed that age (β = -0.338, p = 0.045), gender (β = 0.274, p = 0.045), body mass index (β = -0.230, p = 0.045) and logACR (β = -0.151, p = 0.004) were the only independent predictors of exercise capacity. Increased ACR is associated with diminished exercise capacity in the early stages of essential hypertension independently from adverse cardiac adaptations, further elucidating the adverse prognostic role of albuminuria in this setting.