Microalbuminuria and left ventricular mass in overweight and obese hypertensive patients: role of the metabolic syndrome.

BACKGROUND

Left ventricular hypertrophy (LVH) and microalbuminuria are common in hypertensive patients and are often associated with metabolic syndrome (MetS). However, it is not clear whether MetS could modify the association between cardiac and renal damage.

OBJECTIVE

The aim of this study was to assess if the relationship of albumin/creatinine ratio (ACR) and left ventricular mass (LVM) could be independent from MetS in hypertensive overweight/obese patients.

METHODS

180 essential hypertensive and overweight/obese (body mass index [BMI] ≥25 kg/m(2)) patients referred to our Hypertension Centre from January 2006 to April 2009 because of blood pressure (BP) control-related problems were studied. Exclusion criteria were scarce adherence to antihypertensive drug therapy as investigated by the Morisky Medical Adherence Scale (MMAS), heart failure (New York Heart Association III or IV or left ventricular ejection fraction [LVEF] <50%), liver failure, cancer or other systemic severe diseases. MetS was defined according to the National Cholesterol Education Program (USA) Adult Treatment Panel III classification as modified by the American Heart Association. ACR was obtained from first morning urine specimens. Left ventricular dimensions, mass and ejection fraction, were measured by echocardiography following the American Society of Echocardiography recommendations.

RESULTS

Patients with microalbuminuria had a 6-fold higher risk for LVH/h(2.7) and 2-fold higher risk for LVH/body surface area (BSA). Univariate linear regression analysis showed a positive relationship between ACR and LVM, expressed both as LVM/h(2.7) or LVM/BSA, as well as a direct correlation between logACR and interventricular diameters and ejection fraction. Regression models including logACR, estimated glomerular filtration rate, BMI, age, hypertension duration, smoking and MetS (as a single variable as well as each single component), showed that only logACR, BMI, hypertension duration and systolic blood pressure (SBP) were independently associated with LVM/h(2.7).

CONCLUSION

Along with BP and BMI, albuminuria measured in a morning urine sample as ACR is a valuable low-cost index of cardiac organ damage and increased cardiovascular risk in hypertensive patients independently by MetS. On the other hand, MetS is not an independent risk factor for cardiac damage because it does not seem to add anything more than the sum of each of its components (especially SBP and adiposity indexed by BMI) to the relationship between cardiac and renal subclinical organ damage.