Metabolic syndrome, independent of its components, affects adversely cardiovascular morbidity in essential hypertensives

Abstract

Background: The metabolic syndrome (MS) is widespread among hypertensive patients. However, the net impact of MS on major atherosclerotic events beyond the cardiovascular risk imposed by its individual components remains controversial in this group. We sought to assess both the independent and incremental prognostic role of MS for unfavorable cardiovascular events in a cohort of essential hypertensives.

Methods: We followed up 2176 essential hypertensives free of cardiovascular disease for a median period of 40 months. All subjects had at least one annual visit. MS was defined according to the updated NCEP III criteria. Endpoint of interest was the incidence of stroke, coronary artery disease (CAD) and their composite.

Results: MS was present at baseline in 819 hypertensives (37.6%). MS group presented increased prevalence of resistant hypertension in comparison to MS free group (18.4% versus 10.6%, p < 0.001). The incidence of the composite end-point was 3.1% (69 events) across the follow-up period. Patients with MS were more likely to experience major adverse cardiovascular events (MACE) in comparison to reference category (3.7% versus 1.9%, log rank p = 0.024). While MS was an independent predictor for MACE, none of the individual components of the syndrome was associated independently with the endpoint. MS provided incremental discriminative value (Harrell's c, p < 0.05 for all) over individual risk factors for the incidence of MACE.

Conclusions: MS predicts adverse cardiovascular events in hypertensives incrementally of its individual components. Early identification of MS in this population may enable more accurate prediction of future cardiovascular risk and could implement more efficient strategies in terms of primary prevention.

Keywords: Cardiovascular risk; Hypertension; Metabolic syndrome.