Abstract

BACKGROUND
Diabetic patients have a 3-fold risk for cerebrovascular disease compared with nondiabetic controls. The aim of the present study was to investigate the association of insulin resistance with pulsatility index (PI) of cerebral arteries in type 2 diabetic patients. METHODS: We compared a group of 90 patients with stroke free, type 2 diabetes and an age- and sex-matched control group of 45 healthy subjects without diabetes. Diabetic patients were divided into 3 groups according to the ISI (insulin sensitivity index). We evaluated PI of the middle cerebral artery (MCA) by transcranial Doppler ultrasonography (TCD) and insulin resistance determined by short insulin tolerance test. RESULTS: The PI was significantly higher in diabetic patients than that in healthy controls (P < 0.05), and also higher in patients with insulin resistance than that in insulin sensitive diabetic patients (P < 0.05). The PI of the MCA was significantly correlated with age (r= 0.465, P < 0.01), duration of diabetes (r = 0.264, P = 0.025), hypertension (r = 0.285, P = 0.015) and inversely correlated with insulin resistance (r = -0.359, P = 0.030).Multiple regression analysis was performed with PI as a dependent variable and insulin resistance as an independent variable along with known clinical risk factors. Age (beta = 0.393, P < 0.01) and duration of diabetes (beta = 0.274, P = 0.043) exhibited a significant independent contribution to PI. CONCLUSIONS: PI might be useful markers of the detection of diabetic cerebrovascular changes and insulin resistance, measured with short insulin tolerance test, showed correlations with PI, but age and duration of diabetes contributed independently to the variability in the PI.

• Keywords: Insulin resistance;Pulsatility index;Type 2 diabetes