The overall goals of this project are to characterize the determinants of vascular structure and function, and evaluate their effects on cardiovascular morbidity and mortality 1. Increased aortic pulse wave velocity (aPWV) has been associated with mortality in clinical but not general populations. Aortic PWV was measured at baseline in 2488 older adults. Over an average of 4.6 years of follow-up, 265 deaths occurred with 111 categorized as cardiovascular in cause. Higher aortic aPWV quartile was associated with both total mortality (P = 0.010) and CV mortality (P=.006), independent of age, gender, race, SBP, known CV disease, creatinine, cholesterol and smoking. Thus, among a generally healthy, well-functioning, community dwelling population, aPWV, a marker of arterial stiffness, is associated with higher total and CV mortality (Circulation 2005;111(25):3384-3390). 2. Several case-control studies and a few longitudinal studies have linked the presence of the apoE4 allele with a higher frequency of coronary heart disease. We recently found that the presence of the apoE4 allele is a strong predictor of de novo coronary events in initially healthy volunteers from the Baltimore Longitudinal Study of Aging. Because the increased risk of cardiovascular (CV) disease associated with apoE4 is not exclusively mediated through higher cholesterol levels, we hypothesized that apoE4 might affect the natural history of atherosclerotic disease by altering other CV risk factors.
The aims of the present study were to investigate the interactions between apoE4 and the longitudinal changes in traditional CV risk factors [blood pressure, body mass index (BMI), total and high-density-lipoprotein (HDL)-cholesterol, triglycerides, and blood glucose]. Three hundred six men from the Baltimore Longitudinal Study of Aging, ranging in age from 20 to 92 yr, were studied. Repeated measurements of CV risk factors were performed over a median follow-up time of 7 yr (maximum 14.3 yr). Longitudinal changes in these CV risk factors were analyzed by linear mixed-effects models. The prevalence of the apoE4 allele was 25.5%. apoE4 was independently associated with accelerated changes over time in fasting plasma glucose (+9.5% vs. no change in those without apoE4 in the 6th age-decade over 10 yr). No significant effect of apoE4 on longitudinal changes in total or HDL-cholesterol, triglycerides, or blood pressures was observed. Thus, ApoE4 influences fasting plasma glucose and its changes over time. This could explain, in part, the increased CV risk associated with the apoE4 genotype observed in men (Am J Physiol 2005;289:E322-327). 3. The prevalence of the metabolic syndrome, a potent risk factor for cardiovascular diseases, has not been adequately explored in older individuals. Moreover, 2 sets of criteria have been proposed for the definition of the metabolic syndrome, one by the World Health Organization (WHO) and one by the National Cholesterol Education Program (ATPIII). We found that the prevalence of this syndrome in a subgroup of 2175 older participants from the Cardiovascular Health Study (CHS) free of cardiovascular disease at baseline to be 28.1% by ATPIII criteria, and 21.0%, by WHO criteria. The two sets of criteria provided concordant classification for 80.6% of participants. Multivariate Cox propotional hazard models showed that the metabolic syndrome defined with the ATPIII criteria, but not with the WHO criteria, was an independent predictor of coronary or cerebrovascular events, and was associated with a 38% increased risk (HR 1.38, 95%CI 1.06-1.79, p< 0.01). Thus, as defined by the ATPIII criteria, the metabolic syndrome yields independent prognostic information, even after adjusting for traditional cardiovascular risk factors and the individual domains of the metabolic syndrome (Diabetes Care 2005;28(4):882-887). 4. Increased thickness and stiffness of large arteries may contribute to why aging is the most important risk for cardiovascular diseases. Several large studies have shown that moderate alcohol consumption reduces the risk for heart disease and stroke. We examined whether alcohol consumption alters age-associated increases in arterial stiffness and intimal medial thickness (IMT). A total of 563 volunteers from the Baltimore Longitudinal Study of Aging had carotid duplex ultrasonography with measurements of IMT and an arterial stiffness index. Alcohol intake was assessed by a standard questionnaire. A U-shaped relationship was found between alcohol intake and stiffness index, with the lowest index in moderate drinkers (1 ? 9.9 drinks per week); this relationship persisted after adjustment for cardiovascular risk parameters. Moderate drinkers showed ~ 50% less age-associated increase in arterial stiffness than heavy drinkers and nondrinkers, both before and after adjusting for other cardiovascular risk factors. A significant positive u-shaped relationship was found between alcohol intake and IMT, which did not persist after adjustment for risk factors. Thus, light to moderate alcohol intake favorably modulates aging of the arterial tree. This effect may explain in part the J- or U-shaped relationship between alcohol intake and cardiovascular disease (Am J Cardiol. 2005;95(8):1006-10). 5. Long-term beta blocker therapy improves outcomes in patients with congestive heart failure (CHF). Outpatient beta blocker titration usually requires frequent clinic visits to monitor hemodynamics and symptoms. We developed an automated voice-interactive telemedicine system to assess symptoms, pulse, and blood pressure using home monitoring devices with information relayed via the telephone to a computer database which could be accessed by health care providers. Forty-nine patients with CHF not receiving beta-blockers were randomized to a TeleWatch assessment guided (TG) or outpatient clinic assessment guided (CG) carvedilol titration schedule with a goal of 25 mg BID over a three month period. Titration decisions were made by physicians blinded as to whether the information provided to them was obtained using the TG or CG data. The titration time was significantly shorter in the TG, compared to the CG group, 32.4 days versus 67.8 days, p<0.001. On multiple linear regression analysis, group assignment (p<0.001), final carvedilol dose (p=0.02) and NYHA class (p=0.04), were independently correlated to the duration of titration, while age, ejection fraction, pulse and systolic blood pressure were not. Thus, an automated telemedicine system can safely and significantly decrease the time to achieve carvedilol titration in CHF outpatients (Am Heart J 2006;151:844.e1-10. 6.Numerous studies have implicated trait anger and hostility in the pathogenesis of coronary heart disease. We investigated the associations of anger frequency (trait anger), expression (anger-out) and suppression (anger-in) with carotid artery intimal medial thickness and stiffness in younger and older healthy volunteers from the Baltimore Longitudinal Study of Aging. We found that anger suppression is an independent determinant of carotid arterial stiffness, but we did not observe any association between anger and carotid arterial thickness. Whether behavioral interventions focusing on anger expression can be effective in preventing or reversing arterial stiffness and its attendant cardiovascular risks deserve further evaluation. (Am J Hypertens in press).
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