Impact of type 2 diabetes mellitus on aortic elastic properties in normotensive diabetes: Doppler tissue imaging study.

OBJECTIVES

The stiffening of aorta and other central arteries is a potential risk factor for increased cardiovascular morbidity and mortality. The association of hypertension with type 2 diabetes may obscure the degree to which diabetes alone contributes to impaired arterial function. This study examined whether the presence of type 2 diabetes alone is associated with an impaired aortic mechanical function in patients with or without coronary artery disease (CAD).

METHODS

In all, 154 patients were recruited and assigned to groups A (n = 46, type 2 diabetes with no CAD), B (n = 64, nondiabetic CAD), or C (n = 44, diabetes with CAD) and 20 age- and sex-matched healthy participants were enrolled in a control group. Patients were recruited from those sent for coronary angiography. CAD was excluded for group A. Pulse pressure, aortic strain, and distensibility were calculated from the aortic diameters measured by echocardiography and blood pressure obtained by sphygmomanometer. Aortic wall systolic velocity was measured using pulsed wave Doppler tissue imaging.

RESULTS

Pulse pressure was significantly higher in patient groups A, B, and C in comparison with control group (40.2 +/- 9, 40.1 +/- 11, and 50.2 +/- 13 vs 35.5 +/- 9 mm Hg [P < .01], respectively). The pulsatile change in the aortic diameter and distensibility were less in the patient groups than in the control group (11 +/- 4%, 8 +/- 5%, and 8 +/- 4% vs 17 +/- 9% [P<.001], and 6 +/- 2, 6 +/- 1, and 3 +/- 2 vs 10 cm(2)/dyne/10(3), respectively). In addition, the aortic wall systolic velocity was significantly lower in patient groups compared with control group (6 +/- 2, 6.1 +/- 1, and 5.1 +/- 1 vs 8.5 +/- 1.5 cm/s [P < .01], respectively). Although aortic function parameters were very declined for group C, there was no significant difference between groups A and B that reflected equivalent risk. In diabetic groups A and C, aortic strain, distensibility, and aortic wall systolic velocity showed strong negative correlation with the duration of diabetes (r = -.53, r = -.68, and r = -.56, respectively) and glycosylated hemoglobin (HBA(1)) (r=-.64 [P < .01], r = -.77 [P < .001], and r = -.57 [P < .01], respectively).

CONCLUSION

The increased aortic stiffness that affects patients with type 2 diabetes seems to be an early event that may explain why patients with diabetes have a particularly high risk of developing cardiovascular complications. Poor glycemic control and duration have detrimental effect on aortic elastic properties.