Cerebrovascular reserve capacity in patients with hyperlipidemia

Abstract

Purpose. Because recent data are conflicting, it is not certain whether hyperlipidemia is an independent risk factor for cerebrovascular diseases. Decreased cerebrovascular reserve capacity refers to the decreased ability of the cerebral arterioles to adapt in critical conditions and probably predicts a higher risk of stroke. The aim of this study was to compare cerebrovascular reserve capacity in hyperlipidemic patients and healthy controls using transcranial Doppler sonography.Methods. Thirty-four hyperlipidemic patients and 21 healthy controls were examined. With transcranial Doppler sonography, the mean blood flow velocity in the middle cerebral artery was registered at rest and at 5, 10, 15, and 20 minutes after intravenous administration of 1,000 mg acetazolamide. Cerebrovascular reactivity and reserve capacity were calculated from mean blood flow velocities. Various laboratory measurements were also made and assessed for correlation with resting cerebral blood flow velocity and cerebrovascular reserve capacity.Results. No significant differences could be observed between controls and hyperlipidemic patients in cerebrovascular reactivity or cerebrovascular reserve capacity. No correlation was found between various laboratory measurements and resting cerebral blood flow velocity or cerebrovascular reserve capacity.Conclusions. We could not demonstrate any differences in cerebrovascular reserve capacity between hyperlipidemic patients and healthy controls. Thus, the vasodilatory ability of the cerebral arterioles seems to remain unchanged in this patient group and is not correlated with the severity of hyperlipidemia.

Acetazolamide as a vasodilatory stimulus in cerebrovascular diseases and in conditions affecting the cerebral vasculature

“…CRC was normal in this patient group. Others, using transcranial Doppler, could not detect any differences between the CVR capacity of hypercholesterolemic patients and that of the normal subjects (Kerenyi et al, 2000).…”

Comparison of regional vasomotor responses to acetazolamide and CO2 in rabbit cerebrum and cerebellum, measured by a hydrogen clearance method

“…Areas with low CVR might be vulnerable during marked blood pressure changes and this insufficient compensatory mechanism may not be able to prevent sudden CBF alterations. Experimental studies have shown that the CVR may also depend on the underlying diagnosis related to the intracranial pathology (Brauer et al 1998, Kerenyi et al 2000, Piechnik et al 2001. Current knowledge is still fragmentary as regards the utility of these vasodilatory tests in establishing the appropriate management via determination of the CVR in different brain regions in the event of an intact circulation (Sato et al 1984), although this could be of clinical interest.…”

“…Experimental studies have shown that the CVR may also depend on the underlying diagnosis related to the intracranial pathology (Brauer et al. 1998, Kerenyi et al. 2000, Piechnik et al.…”

Changes in Cerebral Blood Flow Detected by SPECT in Type 1 and Type 2 Diabetic Patients

“…In our study, we found a positive association between basal circulation and HDL cholesterol, whereas acetazolamidestimulated blood flow had a significant positive association with HDL cholesterol and it correlated negatively with triglyceride. These data agree with the atherogenic dyslipidemia found previously in diabetic patients but conflict with the results of Kerényi et al, who could not detect any difference in the reserve capacity between hyperlipidemic patients and healthy subjects using transcranial Doppler ultrasound (20). It is a possible explanation that the patients participating in the latter study had isolated hypercholesterolemia and no diabetes, an only slightly elevated triglyceride level, and a normal HDL level.…”