Carotid haemodynamic parameters as risk factors for cerebral infarction in Type 2 diabetic patients.

Abstract

The purpose of this study was to investigate the usefulness of carotid haemodynamic parameters, i.e. the resistive index (RI) and the pulsatility index (PI), in estimating the risk of cerebral infarction in Type 2 diabetic patients. Three hundred and eighty-two Type 2 diabetic patients (223 men and 159 women; mean age 61 years, range 40-88; 40 had a history of cerebral infarction) and 110 control subjects were analysed in a cross-sectional study. All subjects underwent ultrasonography of the common carotid artery, with determination of intima-media thickness (IMT), RI, and PI. A SMART (Second Manifestations of ARTerial Disease) atherosclerosis risk score was determined for all diabetic patients. The mean values for IMT, RI, and PI were increased in diabetic patients compared with control subjects, and they were significantly elevated in patients with previous cerebral infarction compared with patients without cerebral infarction. (IMT 0.88 +/- 0.22 vs. 0.77 +/- 0.19, P < 0.005; RI 0.77 +/- 0.07 vs. 0.75 +/- 0.06, P < 0.05; PI 1.88 +/- 0.36 vs. 1.71 +/- 0.36, P < 0.01) Significant but weak correlations were found between SMART risk scores and IMT, RI and PI (IMT r = 0.390, P < 0.0001; RI r = 0.346, P < 0.0001; PI r = 0.393, P < 0.0001). The multiple logistic model showed that both the IMT [odds ratio (OR) 6.50, 95% confidence interval (CI) 3.42, 12.34] and the PI (OR 4.16, 95% CI 2.36, 7.34) were independent risk factors for cerebral infarction. The subjects who had an IMT of > 1.0 and a PI > 2.00 had a greater risk of developing a cerebral infarction than did the subjects who had an IMT of < 1.0 and a PI < 2.00 (OR 6.21, 95% CI 2.26, 17.05). The results of this cross-sectional study showed that the measurement of haemodynamic parameters was useful, together with IMT, in estimating the risk of previous cerebral infarction in Type 2 diabetic patients. The predictive value of these parameters in identifying the risk of future cerebral infarction must await the results of future prospective studies.