I. Velcheva 1, P. Damianov 1, K. Stambolieva 2
1 University Hospital of Neurology and Psychiatry, Medical University – Sofia,
2 Institute of Neurobiology, Bulgarian Academy of Sciences – Sofia, Bulgaria

Objective: To study the changes of the cerebral vascular reactivity after different stimuli in patients with diabetes mellitus type 2.

Material and Methods: Twenty patients with diabetes mellitus type 2 (age range 45-67years) and 10 presumed healthy age and sex matched controls were included in the study. Simultaneous transcranial Doppler, blood pressure and heart rate monitoring was performed at rest and after cold stress, deep breathing and head-up tilt. The systolic (SBP), diastolic (DBP) and mean blood pressure (MBP) were measured and the blood flow velocity (BFV) parameters of the middle cerebral artery (MCA) were recorded. Comparison of the effects of the different stimuli on the blood pressure and BFV was performed.

Results: At rest the SBP, DBP and MBP were higher in the patients with diabetes, while BFV did not show substantial differences. The postural challenge and the deep breathing caused decrease of BFV and it was stronger in the diabetic patients. The cold stress induced increase of the BFV, predominating in the controls. Similar SBP, MBP and DBP responses to the applied stimuli were observed. All three stimuli provoked increase of the vascular resistance, which was more expressed in the diabetes group.

Discussion: The assessment of the impaired vascular reactivity after different stimuli is useful for the evaluation of the cerebral hemodynamics in diabetes.

Key words: cerebrovascular reactivity, cold stress, diabetes mellitus, head-up tilt.

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