Bloqueio do receptor mineralocorticoide em hipertensos com síndrome metabólica: estudo da vasodilatação fluxo-mediada

Abstract

INTRODUCTION: The epidemic of obesity and metabolic syndrome (MS) described in recent years is associated with a series of clinical conditions such as malignancy, diabetes mellitus, and cardiovascular diseases, chiefly systemic arterial hypertension (AH). There are several mechanisms proposed to explain the development of MS-associated AH, among which the role of aldosterone and endothelial dysfunction are noteworthy. OBJECTIVES: assess the effects of mineralocorticoid receptor blockade (MRB) on endothelial function, blood pressure (BP) and inflammatory and renal parameters of individuals with the MS. PATIENTS AND METHODS: Forty-two eligible patients were selected. All volunteers underwent clinical examination, laboratory determination of inflammatory mediators and urinary albumin excretion, and cardiologic examination with 24-hour ambulatory blood pressure (24-h ABPM), echocardiography and assessment of the flow-mediated vasodilation (FMD) at baseline and after treatment. Twenty-eight individuals received spironolactone (SPIRO), 25-50mg/day, and 14 individuals received amlodipine (AMLO), 5-10mg/day, for 16 weeks (Results 1). In order to homogenize the groups and better compare the FMD and the inflammatory and renal parameters, 27 individuals were selected and allocated to two groups according to the propensity score (PS) technique: 16 individuals treated with SPIRO and 11 controls, treated with AMLO, for 16 weeks (Results 2). Results 1: Both SPIRO-treated and AMLO-treated groups had significant BP reductions. While the SPIRO-treated group had increased FMD, the AMLO-treated group had a significant reduction of this parameter. There was also a significant reduction of microalbuminuria and inflammatory mediators in the SPIRO-treated group, but not in the AMLO one. There was a significant increase of HDL-cholesterol in the SPIRO group, but not in the AMLO one. Results 2: With the PS technique, and consequent better homogenization of the groups, we confirmed these findings in the two groups (SPIRO and AMLO) and further subdivided them into those with inflammation (CRP>3.0mg/dl) and those without inflammation (CRP<3.0mg/dl). There were significantly increased FMV, greater BP reduction, increased HDL-cholesterol, and significant reduction of albuminuria in the SPIRO group, notably in the subgroup without inflammation, as compared with that with inflammation.

CONCLUSION: MRB in hypertensive subjects with the MS improved endothelial function and reduced blood pressure, with a favorable impact on metabolic and inflammatory markers and on the urinary albumin excretion. These findings point to MRB as a new option for treatment of AH in individuals with the MS.