Physical activity is inversely associated with microalbuminuria in hypertensive patients at high cardiovascular risk: data from I-SEARCH

AIMS: Microalbuminuria (MAU) is a marker for endothelial dysfunction and a predictor of increased cardiovascular risk. Physical activity improves endothelial function. This analysis aims to explore the impact of regular physical exercise on the prevalence and the degree of MAU in hypertensive individuals at high cardiovascular risk. METHODS AND RESULTS: The International Survey Evaluating microAlbuminuria Routinely by Cardiologists in patients with Hypertension (I-SEARCH) studied the prevalence of MAU in 20,786 hypertensive patients at high cardiovascular risk. Herein, we investigated the relationship between self-reported physical activity and MAU in relation to the number of cardiovascular risk factors, medication and co-morbidities. A total of 7123 patients (34.3%) performed regular physical exercise (moderate or strenuous, at least 4 hours per week). The prevalence of MAU was significantly lower in active than in inactive patients (54% vs 61%; P < 0.0001). This association was observed in all classes of blood pressure and heart rate and was similar in patients with and without diabetes mellitus. Urinary albumin excretion (UAE) was lower in active than in inactive patients (UAE 80 mg/l: 11.6% vs 13.5%, P < 0.0001; UAE 150 mg/l: 7.5% vs 10%; P < 0.0001). In a multivariate analysis adjusted for age, gender, blood pressure, heart rate, renal function, medication and comorbidities, regular physical activity was associated with a 25% lower risk for MAU (odds ratio (OR) 0.75; 95% confidence interval (CI), 0.67-0.84; P < 0.0001). Risk reduction for MAU was more pronounced in strenuously active (OR 0.66; 95%CI, 0.47-0.95; P < 0.05) than in moderately active patients (OR 0.76; 95%CI, 0.68-0.85; P < 0.0001). CONCLUSION: In hypertensive patients at high cardiovascular risk, physical activity is an independent predictor for a decreased risk of microalbuminuria.