The association of atherosclerosis,vascular risk factors,and retinopathy in adults with diabetes : the atherosclerosis risk in communities study

PURPOSE: The aim of this report is to describe the prevalence of retinopathy and its associations with atherosclerosis and vascular risk factors in people with diabetes. DESIGN: Cross-sectional study. PARTICIPANTS: Persons with diabetes, having gradable fundus photographs, from a biracial population-based cohort of adults (ages 51-72 years), and living in four United States communities (Forsyth County, North Carolina; the city of Jackson, Mississippi; suburbs of Minneapolis, Minnesota; and Washington County, Maryland) were studied from 1993 to 1995. METHODS: Lesions typical of diabetic retinopathy were detected by grading a 45 degrees color fundus photograph of one eye of each participant, using a modification of the Airlie House classification system. MAIN OUTCOME MEASURE: Severity of diabetic retinopathy (none, minimal nonproliferative, moderate nonproliferative, severe nonproliferative, and proliferative) and macular edema. RESULTS: Retinopathy was detected in 328/1600 (20.5%) of those with diabetes; 114/1724 (6.6%) had hard exudate, 28/1600 (1.8%) had proliferative diabetic retinopathy, and 27/1662 (1.6%) had macular edema. The prevalence of diabetic retinopathy was higher in blacks (27.7%) compared with whites (16.7%). Controlling for duration of diabetes, serum glucose, systolic blood pressure, and type of diabetes medications taken, severity of retinopathy was associated with carotid artery intima-media wall thickness (odds ratio [OR]/0.1-mm thickness 1.09; 95% confidence interval [CI], 1.01, 1.17; P = 0.01), serum albumin (OR/0.1 g/dl 0.94; 95% CI, 0.88, 0.99; P = 0.02), but not race (OR blacks versus whites,1.24; 95% CI, 0.88, 1.75; P = 0.21). Severity of diabetic retinopathy was not associated with coronary artery disease or stroke history or any of the plasma lipids studied. Controlling for age, gender, duration of diabetes, serum glucose, and type of diabetes medications taken, the presence of retinal hard exudates was associated with plasma low-density lipoprotein cholesterol (OR/10 mg/dl 1.18; 95% CI, 1.09, 1.29; P < 0.001), and plasma Lp(a) (OR/10 mg/dl 1.02; 95% CI, 1.00, 1.05; P = 0.04) but not race or blood pressure. CONCLUSIONS: These data suggest that plasma lipids are associated with the presence of hard exudate and that carotid artery intima-media wall thickness is associated with retinopathy, but other manifestations of atherosclerosis and most of its risk factors are not associated with severity of diabetic retinopathy.     

Postural changes in blood pressure and incidence of ischemic stroke subtypes: the ARIC study

The relation of orthostatic blood pressure decrease, or increase, with occurrence of ischemic stroke subtypes has not been examined. We investigated the association of orthostatic blood pressure change (within 2 minutes after supine to standing) obtained at baseline (1987 to 1989) in the Atherosclerosis Risk in Communities Study with incidence of ischemic stroke subtypes through 2007. Among 12 817 black and white individuals without a history of stroke at baseline, 680 ischemic strokes (153 lacunar, 383 nonlacunar thrombotic, and 144 cardioembolic strokes) occurred during a median follow-up of 18.7 years. There was a U-shaped association between orthostatic systolic blood pressure change and lacunar stroke incidence (quadratic P=0.004). In contrast, orthostatic systolic blood pressure decrease of 20 mm Hg or more was associated with increased occurrence of nonlacunar thrombotic and cardioembolic strokes independent of sitting systolic blood pressure, antihypertensive medication use, diabetes, and other lifestyle, physiological, biochemical, and medical conditions at baseline (for nonlacunar thrombotic: hazard ratio, 2.02; 95% CI, 1.43 to 2.84; for cardioembolic: hazard ratio, 1.85, 95% CI, 1.01 to 3.39). Orthostatic diastolic blood pressure decrease was associated with increased risk of nonlacunar thrombotic and cardioembolic strokes; the hazard ratios (95% CI) associated with 10 mm Hg lower orthostatic diastolic blood pressure (continuous) were 1.26 (1.06 to 1.50) and 1.41 (1.06 to 1.88), respectively, in fully adjusted models. In conclusion, the present study found that nonlacunar ischemic stroke incidence was positively associated with an orthostatic decrease of systolic and diastolic blood pressure, whereas greater lacunar stroke incidence was associated with both orthostatic increases and decreases in systolic blood pressure.     

Cerebral white matter lesions,retinopathy, and incident clinical stroke

Context  White matter lesions (WMLs) detected on cerebral imaging scans havebeen hypothesized to have a microvascular etiology and to precede the developmentof clinical stroke. However, few clinical data are available to support thesehypotheses. Objective  To examine the relationship of WMLs, retinal microvascular abnormalities,and incident clinical stroke in healthy, middle-aged men and women. Design and Setting  The Atherosclerosis Risk in Communities Study (ARIC), a prospective,population-based cohort study conducted in 4 US communities and initiatedin 1987-1989. Participants  A total of 1684 persons aged 51 to 72 years who had cerebral magneticresonance imaging (MRI) and retinal photography at the third examination (1993-1995). Main Outcome Measures  Odds of WMLs, defined by standardized methods from MRI, by presenceor absence of specific retinal microvascular abnormality (eg, microaneurysm,retinal hemorrhage) on retinal photograph; incident clinical stroke, ascertainedafter a median follow-up of 4.7 years, according to presence or absence ofWMLs and retinopathy. Results  Persons with retinopathy were more likely to have WMLs than those withoutretinopathy (22.9% vs 9.9%; odds ratio, 2.5; 95% confidence interval [CI],1.5-4.0, adjusted for age, sex, race, and vascular risk factors). The 5-yearcumulative incidence of clinical stroke was higher in persons with vs withoutWMLs (6.8% vs 1.4%; adjusted relative risk [RR], 3.4; 95% CI, 1.5-7.7) andin persons with vs without retinopathy (8.0% vs 1.4%; adjusted RR, 4.9; 95%CI, 2.0-11.9). Persons with both WMLs and retinopathy had a significantlyhigher 5-year cumulative incidence of stroke than those without either WMLsor retinopathy (20.0% vs 1.4%; adjusted RR, 18.1; 95% CI, 5.9-55.4). Conclusions  In this cohort, middle-aged persons with cerebral WMLs detected on MRIwere more likely to have retinal microvascular abnormalities and to have anincreased risk of clinical stroke than people without WMLs. The risk of strokewas higher when retinopathy was simultaneously present in persons with WMLs.      

Comparison of the prognostic significance of the electrocardiographic QRS/T angles in predicting incident coronary heart disease and total mortality (from the atherosclerosis risk in communities study)

Spatial QRS/T angle and spatial T-wave axis were shown to be strong independent predictors of incident coronary heart disease (CHD) and total mortality, but they are not routinely available. We evaluated whether frontal plane QRS/T angle, easily obtained as the difference between frontal plane axes of QRS and T, provides a suitable substitute for spatial QRS/T angle as a risk predictor. Our study consisted of 13,973 participants from the ARIC Study. Outcome variables were incident CHD and total mortality during a median follow-up of 14 years. Electrocardiographic variables were categorized as abnormal (>/=95th percentile), borderline (>/=75th and <95th percentile), and normal (<75th percentile) separately for men and women. Cox regression was used to assess the effect of electrocardiographic variables on risk of each outcome. The normal category was considered the reference cell. With adjustment for demographic and clinical characteristics, both QRS/T angles were approximately equally strong predictors of total mortality with >50% increased risk. Spatial QRS/T angle was a stronger predictor of incident CHD in women, with a 114% increased risk, but it was not significantly associated with risk of incident CHD in men. Similarly, frontal plane QRS/T angle was statistically significant for only women with a 74% increased risk of incident CHD. In conclusion, frontal plane QRS/T angle as an easily derived risk measure is a suitable clinical substitute for spatial QRS/T angle for risk prediction.     

Heart rate-corrected QT interval prolongation predicts risk of coronary heart disease in black and white middle-aged men and women: the ARIC study

OBJECTIVES: We aimed to study the predictive value of heart rate-corrected QT interval (QTc) for incident coronary heart disease (CHD) and cardiovascular disease (CVD) mortality in the black and white general population, and to validate various QT measurements. BACKGROUND: QTc prolongation is associated with higher risk of mortality in cardiac patients and in the general population. Little is known about the association with incident CHD. No previous studies included black populations. METHODS: We studied the predictive value of QTc prolongation in a prospective population study of 14,548 black and white men and women, age 45 to 64 year. QT was determined by the NOVACODE program in the digital electrocardiogram recorded at baseline. RESULTS: In quintiles of QTc, cardiovascular risk profile deteriorated with longer QTc, and risk of CHD and CVD mortality increased. The high risk in the upper quintile was mostly explained by the 10% with the longest QTc. The age-, gender-, and race-adjusted hazard ratios for CVD mortality and CHD in subjects with the longest 10% relative to the other 90% of the gender-specific QTc distribution were 5.13 (95% confidence interval 3.80 to 6.94) and 2.14 (95% confidence interval 1.71 to 2.69), respectively. The increased risk was partly, but not completely, attributable to other risk factors or the presence of chronic disease. The association was stronger in black than in white subjects. Manual- and machine-coded QT intervals were highly correlated, and the method of rate correction did not affect the observed associations. CONCLUSIONS: Long QTc is associated with increased risk of CHD and CVD mortality in black and white healthy men and women.     

Smoking and diabetes differ in their associations with subclinical atherosclerosis and coronary heart disease-the ARIC Study

Atherosclerosis, nearly universally present in major arteries of Western adults, is characterized in all affected arteries by cholesterol-laden plaques and consistently associated with blood cholesterol levels. Other risk factors are reported to have relatively stronger or weaker associations with different atherosclerotic manifestations, but such differences have never previously been quantified. Measuring them may offer fresh clues to atherogenic processes and their prevention. The Atherosclerosis Risk in Communities Study (ARIC) ascertained incident coronary heart disease (CHD) and measured subclinical atherosclerosis as carotid artery intimal medial thickness using ultrasound and as lower extremity arterial disease (LEAD) using ankle-brachial blood pressure index. Blood cholesterol was associated with all endpoints. When standardized against LDL cholesterol associations, diabetes and smoking showed substantially different strengths of associations with different endpoints. Relative to associations with LDL cholesterol: (1) smoking, but not diabetes, increased in its strength of association with the severity of the underlying arterial disease; (2) the diabetes and smoking associations with CHD were much stronger in women than men, a phenomenon which, the standardization pattern suggests, is due to a gender difference in CHD pathogenesis, possibly attributable to arteriolar differences.