Effect of Renin-Angiotensin system inhibition on cardiovascular events in older hypertensive patients with metabolic syndrome.

OBJECTIVE: Metabolic syndrome (MetS) is associated with cardiovascular disease (CVD). Insulin resistance has been hypothesized as the underlying feature of MetS. Angiotensin converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARB) are widely used antihypertensives that may improve insulin sensitivity. The aim of the study is to evaluate the effect of ACEI/ARB on incident CVD events in older hypertensive patients with MetS. MATERIALS/METHODS: We used the Cardiovascular Health Study, a prospective cohort study of individuals>65years of age to evaluate ACEI/ARB use and time to CVD events (including coronary and cerebrovascular events). The study included 777 subjects who had hypertension and ATP III-defined MetS, but free of CVD and diabetes at baseline. Cox regression models were used to evaluate the effect of ACEI/ARB as compared to other antihypertensives on the time to the first CVD events. RESULTS: ACEI/ARB use was associated with a decreased risk of CVD events (adjusted HR=0.658, 95 % C.I. [0.436-0.993]) compared to other antihypertensives. When CVD endpoints were evaluated separately, use of ACEI/ARB was associated with lower rates of angioplasty and coronary events (HR of 0.129 and 0.530 respectively, with 95 % CI [0.017-0.952] and [0.321-0.875]). CONCLUSIONS: ACEI/ARB use was associated with a lower risk of CVD events in older hypertensive patients with MetS, primarily due to a reduction in coronary events. The potential protective effect of ACEI/ARB on CVD events in older individuals with MetS will need further confirmation from prospective studies.

Comparison of different metabolic syndrome definitions and risks of incident cardiovascular events in the elderly.

The metabolic syndrome is associated with increased cardiovascular risk, and its prevalence increases with age. Various definitions of the metabolic syndrome exist, but whether some definitions are more predictive of future cardiovascular events in the elderly is unclear. We compared the risk of incident cardiovascular events in elderly individuals at least 65 years old from the Cardiovascular Health Study with and without the metabolic syndrome as defined by the European Group for the Study of Insulin Resistance (EGIR), National Cholesterol Education Program (NCEP)/American Heart Association (AHA), American Association of Clinical Endocrinologists, International Diabetes Federation (IDF), and modified World Health Organization (WHO) criteria (n = 3390). Participants were without baseline diabetes or cardiovascular disease. Except for EGIR, all definitions of the metabolic syndrome were significantly associated with increased risk of incident cardiovascular (coronary or cerebrovascular) events. Adjusted hazard ratios (HRs) for risk of incident cardiovascular events as defined by the modified WHO, NCEP/AHA, American Association of Clinical Endocrinologists, and IDF criteria ranged from 1.153 (P = .045) for NCEP/AHA to 1.314 (P < .001) for IDF, with 95% confidence interval (CI) ranging from 1.003 to 1.503. Adjusted HR for EGIR was 1.087 (95% CI, 0.908-1.301; P = .362). Similarly, all definitions of the metabolic syndrome were significantly associated with incident coronary events except for the EGIR definition. Only the modified WHO definition was associated with increased risk for cerebrovascular events (adjusted HR, 1.301; 95% CI, 1.038-1.631; P = .022). Although all metabolic syndrome definitions except EGIR were associated with total cardiovascular events and coronary events, only the modified WHO definition was also associated with risk of cerebrovascular events.