Abstract 2882: The Combined Impact of Glucose Abnormality and Blood Pressure Category on Carotid Atherosclerosis in a General Urban Japanese Population: The Suita Study

Abstract

Introduction: Diabetes Mellitus (DM) and hypertension (HT) have been proven to be risk factors for cardiovascular diseases and stroke. However, few studies have examined the relationships of carotid artery intima-media thickness (IMT) with combination of glucose abnormality and blood pressure (BP) categories in a general population. We assessed the hypothesis that the effect of the risks of these factors on carotid atherosclerosis was more accentuated with combination of higher categories on glucose and BP in a general urban Japanese population. Methods: Participants (35-93 years of age; 1,844 women and 1,602 men) who gave written informed consent were randomly selected from a general urban population (between 2002 and 2004). Carotid atherosclerosis was evaluated by high-resolution ultrasonography (7.5MHz) with atherosclerotic indexes of IMT in the common carotid artery (CCA), carotid artery bulb (Bulb), and internal and external carotid arteries. Mean IMT was defined as the mean of the IMT of the proximal and distal walls for both sides of the CCA at a point 10 mm proximal to the beginning of the dilation of each Bulb. Maximum IMT was assessed in the entire scanned area. Stenosis (>=25%) was defined as a condition in which a plaque occupied more than 25% of the lumen circumference of an artery on a cross-sectional scan. Serum glucose categories (normoglycemia, impaired fasting glucose [IFG] and DM) were defined according to the 2003 ADA recommendations. BP categories (optimal, normal, high-normal BP and HT) were defined on the basis of the ESH-ESC 2007 criteria. The association of serum glucose categories with the carotid atherosclerotic indexes was investigated through logistic regression analysis considering potential confounding risk variables including BP category. Results: Compared with normoglycemic subjects, the mean and maximum IMTs were significantly greater in women with DM (mean: 0.836 vs 0.802 p=0.001, maximum: 1.370 vs 1.205 p<0.001) and in men with IFG (mean: 0.858 vs 0.838 p=0.004, maximum: 1.511 vs 1.439 p=0.038) and DM (mean: 0.885 vs 0.838 p<0.001, maximum: 1.631 vs 1.439 p<0.001). Compared with normoglycemic subjects, the odds ratios (OR) (95% confidence intervals [CI]) for stenosis was 1.67 (1.22-2.30) in subjects with DM. Compared with optimal BP subjects, the OR (95% CI) for stenosis was 1.52 (1.15-2.01) in subjects with HT. In combination, the OR for stenosis with optimal, normal, high-normal BP and HT were 1(reference), 1.96, 2.48 and 2.71 with normoglycemia, 1.99, 1.83, 2.26 and 2.88 with IFG and 7.04, 2.18, 3.42 and 4.09 with DM (P-value for interaction=0.049). Conclusion: Compared with normoglycemic subjects, the mean and maximum IMTs were significantly greater in women with DM and in men with IFG and DM and stenosis was significantly greater in subjects with DM. The impact of each glucose category on the stenosis was more evident in subjects with a higher BP category.