Increased intracranial arterial resistance in patients with type 2 diabetes mellitus.

BACKGROUND

The majority of the studies investigating risk factors for stroke have focused on the atherosclerosis of extracranial carotid arteries. Risk factors for the involvement of intracranial arteries in patients with stroke have not been widely investigated so far. The pulsatility index reflects 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 diabetes mellitus and some other atherosclerosis risk factors on intracranial vascular resistance in patients with a previous stroke or transient ischemic attack.

METHODS

Transcranial doppler investigations were performed in 103 patients with previous stroke (31 with diagnosis of type 2 diabetes, 72 without diabetes), at least 3 months after stroke occurred. Blood flow velocities of anterior cerebral arteries, middle cerebral arteries, the intracranial part of vertebral arteries and the basilar artery, as well as of the extracranial part of the internal carotid artery were measured, and Gosling's pulsatility index was calculated. The maximal pulsatility index of intracranial arteries was defined to express the most pronounced damage.

RESULTS

Diabetic patients had a significantly higher pulsatility index than non-diabetic patients in all examined intracranial arteries. The maximal pulsatility index was also significantly higher in diabetic patients than in non-diabetic 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 women and between groups of patients with or without hypertension. In the multivariate analysis, the presence of diabetes (p < 0.0001) and the age of patients (p < 0.0001) were the only factors significantly predicting maximal pulsatility index, and this relationship was independent on the presence of hypertension.

CONCLUSIONS

Diabetic patients with previous stroke have a higher pulsatility index than non-diabetic patients with previous strokes, which indicates a higher increase in intracranial arterial resistance and more severe damage to cerebral blood flow in diabetes mellitus.