Increased central artery stiffness in impaired glucose and type 2 diabetes

Abstract

—Impaired glucose metabolism (IGM) and type 2 diabetes (DM-2) are associated with high cardiovascular disease risk. Increases in peripheral and central artery stiffness may represent pathophysiologic pathways through which glucose tolerance status leads to cardiovascular disease. Peripheral artery stiffness increases with deteriorating glucose tolerance status, whereas this trend remains unclear for central artery stiffness. Therefore, we investigated the associations between glucose tolerance status and estimates of central arterial stiffness. We performed a population-based study of 619 individuals (normal glucose metabolism, nϭ261; IGM, nϭ170; and DM-2, nϭ188) and assessed central artery stiffness by measuring total systemic arterial compliance, aortic pressure augmentation index, and carotid-femoral transit time. After adjustment for sex, age, heart rate, height, body mass index, and mean arterial pressure, DM-2 was associated with decreased total systemic arterial compliance, increased aortic augmentation index, and decreased carotid-femoral transit time. IGM was borderline significantly associated with decreased total systemic arterial compliance. Respective regression coefficients (95% confidence intervals) for IGM and DM-2 compared with normal glucose metabolism were Ϫ0.05 (Ϫ0.11 to 0.01) and Ϫ0.13 (Ϫ0.19 to Ϫ0.07) mL/mm Hg for total systemic arterial compliance; 1.1 (Ϫ0.2 to 2.5) and 1.6 (0.2 to 3.0) percentage points for aortic augmentation index; and Ϫ0.85 (Ϫ5.20 to 3.49) and Ϫ4.95 (Ϫ9.41 to Ϫ0.48) ms for carotid-femoral transit time. IGM and DM-2 are associated with increased central artery stiffness, which is more pronounced in DM-2. Deteriorating glucose tolerance is associated with increased central and peripheral arterial stiffness, which may partly explain why both DM-2 and IGM are associated with increased cardiovascular risk. (Hypertension. 2004;43:176-181.) Key Words: diabetes mellitus Ⅲ arteries Ⅲ compliance Ⅲ vascular resistance Ⅲ total peripheral resistance B oth impaired glucose metabolism (IGM) and type 2 diabetes mellitus (DM-2) are associated with a high risk of cardiovascular disease and mortality. 1,2 The mechanisms through which these pathologies increase the risk of cardio-vascular disease remain unclear but might involve increased arterial stiffness, 3– 6 which leads to increased systolic blood pressure and left ventricular mass and hampers coronary filling during diastole. 7 Arterial stiffness varies by region and type of artery. It is likely that increased stiffness of both peripheral and central arteries is detrimental. We have previously shown that as compared with individuals with normal glucose metabolism (NGM), stiffness of peripheral arteries is increased in both IGM (femoral and brachial arteries) and DM-2 (femoral, brachial, and carotid arteries). However, it is unknown whether central artery stiffness is increased in IGM and DM-2. In view of these considerations, we investigated, in a population-based cohort of 619 individuals, the associations of glucose tolerance status with arterial stiffness, expressed as total systemic arterial compliance, which reflects the overall buffering capacity of the arterial system, mainly of the proximal aorta; 8,9 the aortic augmentation index; and the height-adjusted carotid-femoral transit time, a surrogate for carotid-femoral pulse wave velocity, 9 which reflects the stiffness of mainly the descending aorta. 8,9 Total systemic arterial compliance was estimated by 2 methods, namely, by the time decay of diastolic aortic pressure and by the ratio of stroke volume to aortic pulse pressure. Carotid-femoral transit time estimates the average