Patients with type 2 diabetes have two to three times the risk of dying prematurely from cardiovascular disease than their nondiabetic counterparts (1). Many studies have shown that arterial compliance is reduced in type 2 diabetes and that arterial stiffness increases with deteriorating glucose tolerance status, even before the onset of type 2 diabetes (2–4). In a previous brief report, we studied Afro-Caribbean and white Caucasian subjects with diabetes and found a decrease in peripheral arterial compliance in the Afro-Caribbean subjects (5). We also reported an accelerated rate of aging in the elastic arteries of diabetic patients reaching a plateau by the age of 50–60 years (6). The present article examines the control versus diabetic differences in two races, white Caucasians and Afro-Caribbeans, and includes data on Asians from the Indian subcontinent with diabetes.
Fifty-seven patients with a diagnosis of type 2 diabetes for at least 1 year (21 white Caucasian, 20 Afro-Caribbean, and 16 Asian) aged 44–80 years (mean ± SD 61 ± 7.4) and 48 healthy control subjects (30 white Caucasian and 18 Afro-Caribbean) aged 34–86 years (65.5 ± 11.6) took part in this cross-sectional study.
Pulse wave velocity of the carotidfemoral (PWVcf) was measured noninvasively in a thoraco-abdominal segment and in an upper-limb muscular artery (PWV of the carotid-radial [PWVcr]) using the Complior (Colson, Pantin, France) system. PWV from the aorta to the finger (PWVfin) was measured using the Finapress (Ohmeda, Madison, WI) and custom-written software (J.D.C.). Central aortic compliance (CAC) was also assessed from simultaneous measurements of ascending aortic blood flow and surrogate estimates of aortic root pressure using a method described by Liu et al. (7) and previously reported by Cameron et al. (8).
Analysis of the clinical characteristics of the participants for the diabetic and control groups and by ethnicity showed that for the diabetic group, only BMI was significantly different between the races (P < 0.05), with the white patient group having the highest mean value (29.9 kg/m2). For the control population, only age was significantly different (P = 0.01), with Caucasians being on average 8 years older than Afro-Caribbeans.
Race was found to be a major determinant of PWVcr in type 2 diabetic subjects, with Afro-Caribbeans having the highest mean value (12.10 ± 1.4 m/s) of the three ethnic origins (P = 0.03) compared with Caucasians (11.12 ± 1.3 m/s) and Asians (10.95 ± 1.3 m/s). The racial differences were independent of blood pressure. No differences were found between the races for PWVcf, PWVfin, or CAC. Analysis in the control population showed no differences in arterial compliance between the Afro-Caribbeans and Caucasians.
We have shown that there is a racial preponderance of stiffening of the peripheral arteries in diabetic subjects, with subjects of Afro-Caribbean origin having significantly higher mean indexes for PWVcr compared with those of white and Asian origin. Diabetes led to a decrease in the compliance of the aorto-iliac-femoral segment of the arterial system (PWVcf). The muscular arteries of diabetic subjects of Afro-Caribbean origin tended to have a reduced compliance. This difference could reflect the increased complications observed in Afro-Caribbeans with type 2 diabetes.
