Reduced Coronary Artery and Abdominal Aortic Calcification in Hispanics With Type 2 Diabetes

Abstract

OBJECTIVE -To compare lifestyle factors, cardiovascular risk factors, and coronary artery calcium (CAC) and abdominal aortic calcium (AAC) levels in Hispanic and non-Hispanic white (NHW) individuals with type 2 diabetes. RESEARCH DESIGN AND METHODS -We recently demonstrated in a small group of nonreferred, healthy, nondiabetic subjects that CAC was reduced in Hispanics compared with NHWs, despite a worse cardiovascular risk factor profile. In this study, we evaluated whether this ethnic disparity in vascular calcification was present in individuals with type 2 diabetes and in several different arterial beds. Hispanic and NHW subjects (n ϭ 245) with type 2 diabetes were evaluated for cardiovascular risk factors using questionnaires and assays of plasma biomarkers. CAC and AAC were measured by electron-beam computer-assisted tomography.RESULTS -Although Hispanics were slightly younger than NHWs, other standard risk factors and novel cardiovascular risk factors, including plasminogen activator-1 and fibrinogen levels, were similar between the groups. Despite the similar risk factor profile, the prevalence of cardiovascular disease (CVD) and mean and median levels of CAC and AAC were lower in Hispanics. Furthermore, the distribution of these calcium scores differed from that of NHWs (P Ͻ 0.05), with significantly fewer Hispanic subjects having high CAC or AAC scores. These differences were not explained by differences in CVD prevalence or any measured lifestyle or risk factor.CONCLUSIONS -Hispanics with type 2 diabetes have reduced CAC and AAC levels compared with NHW subjects, suggesting a reduction in the overall burden of vascular calcification and atherosclerosis. These data are consistent with the notion that Hispanics are protected against the development of CVD. Diabetes Care 27:1115-1120, 2004N umerous studies over the past several decades, using vital statistics data, have demonstrated reduced rates of total and cardiovascular mortality in Hispanics (1-4). Interestingly, epidemiological studies of cardiovascular risk factors have suggested that Hispanics are frequently more obese and insulin resistant compared with non-Hispanic whites (NHWs) and often, as a result, have higher triglyceride levels and lower HDL cholesterol levels (5-13). This apparent decreased rate of cardiovascular disease (CVD) in Hispanics, despite evidence of increased levels of several traditional and nontraditional risk factors, has been described as the "Hispanic paradox" (14,15). However, in several recent longitudinal cohort studies, rates of CVD have appeared equal or possibly greater in Hispanics compared with their NHW counterparts (16 -20). It is important to note that in several of these studies, the comparison between ethnic groups may have been complicated by the greater prevalence and incidence of diabetes in the Hispanic population, which may greatly enhance the overall cardiovascular risk of this ethnic group in comparison with groups having reduced rates of diabetes.To further assess this potential ethnic disparity in th...

Coronary artery and abdominal aortic calcification are associated with cardiovascular disease in type 2 diabetes

“…The majority of subjects were male (94%) and Caucasian (65%). Other than having a slightly greater percent of female subjects (6% vs 3%, p<0.05), this cohort was representative of individuals in the larger VADT study and was, as previously described [23], on average middle aged (61±9 years), overweight (BMI 31.5±4.3 kg/m 2 ) and in poor glycaemic control (HbA1c 9.2±1.4%). Approximately 35% had baseline evidence of CVD including myocardial infarctions, strokes, bypass surgery, revascularization procedures or PAD.…”

“…Before reading, the brightness of the image was adjusted to a standard brightness using linear regression against the brightness measured in regions of interest inside of the hydroxyapatite bars in the calibration phantom. A CT volume threshold was utilized for identification of calcific lesions as previously described [23]. Each focus exceeding the minimum volume criteria and having greater than 130 Hounsfield units was scored using the algorithm developed by Agatston et al [24] as previously described [23].…”

“…A CT volume threshold was utilized for identification of calcific lesions as previously described [23]. Each focus exceeding the minimum volume criteria and having greater than 130 Hounsfield units was scored using the algorithm developed by Agatston et al [24] as previously described [23]. Total coronary or aortic calcium scores were determined by summing individual lesion scores from each of four anatomic sites (left main, left anterior descending, circumflex, and right coronary arteries) or along the scanned region of the aorta, respectively.…”

Proliferative Diabetic Retinopathy in Type 2 Diabetes Is Related to Coronary Artery Calcium in the Veterans Affairs Diabetes Trial (VADT)

“…METHODS -Data for this study derive from baseline examinations of participants in the Risk Factors, Atherosclerosis and Clinical Events in Diabetes (RACED) study (12), a seven-site substudy of the VADT. A detailed description of the VADT with exclusion and inclusion crite-…”

“…Information regarding current medical health status including history of diabetes, hypertension, prior CVD, and medication use was collected by a questionnaire administered by research staff as previously described (13). A non-Hispanic white variable was generated because this race-ethnicity grouping effectively identifies those with greater CAC in this and other cohorts (12,14,15). All laboratory assays, including plasma total cholesterol, triglycerides, HDL cholesterol concentrations, and A1C, were measured in the central laboratory at Tufts University.…”