Cerebrovascular reserve capacity in patients with hyperlipidemia

Purpose. Because recent data are conflicting, it is not certain whether hyp erlipidemia is an independent risk factor for cerebrovascular diseases. Dec reased cerebrovascular reserve capacity refers to the decreased ability of the cerebral arterioles to adapt in critical conditions and probably predic ts a higher risk of stroke. The aim of this study was to compare cerebrovas cular reserve capacity in hyperlipidemic patients and healthy controls usin g transcranial Doppler-sonography. Methods. Thirty-four hyperlipidemic patients and 21 healthy controls were e xamined. 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. Cer ebrovascular reactivity and reserve capacity were calculated from mean bloo d flow velocities. Various laboratory measurements were also made and asses sed for correlation with resting cerebral blood flow velocity and cerebrova scular reserve capacity. Results. No significant differences could be observed between controls and hyperlipidemic patients in cerebrovascular reactivity or cerebrovascular re serve capacity. No correlation was found between various laboratory measure ments and resting cerebral blood flow velocity or cerebrovascular reserve c apacity. Conclusions. We could not demonstrate any differences in cerebrovascular re serve capacity between hyperlipidemic patients and healthy controls. Thus, the vasodilatory ability of the cerebral arterioles seems to remain unchang ed in this patient group and is not correlated with the severity of hyperli pidemia. (C) 2000 John Wiley & Sons, Inc.