Increased intracranial arterial resistance in patients with type 2 diabetes mellitus

Background. The majority of the studies investigating risk factors for stro ke have focused on the atherosclerosis of extracranial carotid arteries. Ri sk factors for the involvement of intracranial arteries in patients with st roke have not been widely investigated so far. The pulsatility index reflec ts the vascular resistance of intracranial arteries and could therefore be used as an estimate of the severity of vascular damage. Main purpose. The present study aimed to examine the influence of type 2 di abetes mellitus and some other atherosclerosis risk factors on intracranial vascular resistance in patients with a previous stroke or transient ischem ic attack. Methods. Transcranial doppler investigations were performed in 103 patients with previous stroke (31 with diagnosis of type 2 diabetes, 72 without dia betes), at least 3 months after stroke occured. Blood flow velocities of an terior cerebral arteries, middle cerebral arteries, the intracranial part o f vertebral arteries and the basilar artery, as well as of the extracranial part of the internal carotid artery were measured, and Gosling's pulsatili ty index was calculated. The maximal pulsatility index of intracranial arte ries was defined to express the most pronounced damage. Results. Diabetic patients had a significantly higher pulsatility index tha n non-diabetic patients in all examined intracranial arteries. The maximal pulsatility index was also significantly higher in diabetic patients than i n nondiabetic patients (1.24 +/- 0.25 vs. 1.00 +/- 0.23; p < 0.0001). There was no significant difference in the pulsatility index between men and wom en and between groups of patients with or without hypertension. In the mult ivariate analysis, the presence of diabetes (p < 0.0001) and the age of pat ients (p < 0.0001) were the only factors significantly predicting maximal p ulsatility index, and this relationship was independent on the presence of hypertension. Conclusions. Diabetic patients with previous stroke have a higher pulsatili ty index than non-diabetic patients with previous strokes, which indicates a higher increase in intracranial arterial resistance and more severe damag e to cerebral blood flow in diabetes mellitus.