The effects of blood pressure and the renin-angiotensin-aldosterone system on regional cerebral blood flow and cognitive impairment in dialysis patients

Cognitive dysfunction is prevalent in chronic kidney disease patients. Little is known about the relationship between the regional cerebral blood flow (rCBF) and cognitive function in hemodialysis (HD) patients. We used quantitative single-photon emission-computed tomography (SPECT) to determine whether rCBF decreased in these patients. Fifty-four consecutive HD patients who were able to visit the hospital unassisted and had no history of stroke underwent cognitive assessment based on the Mini Mental State Examination (MMSE). Using quantitative image-analysis software, the SPECT imaging data were used to compare rCBF in HD patients and age-matched healthy controls. Thirty-four patients (63%) had MMSE scores >= 28 (non-dementia). Regarding the extent of decreased rCBF in HD patients compared with rCBF in normal control patients, SPECT demonstrated significant rCBF decreases in all patients. rCBF in the perfusion area of the middle cerebral artery was significantly more decreased than in other areas. Multiple logistic regression analysis demonstrated that the presence or absence of a previous history of percutaneous coronary intervention, drug therapy with angiotensin II receptor antagonists and diastolic blood pressure (DBP) were independent risk factors for the extent of decreased rCBF. Regarding the severity of decreased rCBF, stepwise multiple regression analysis indicated that HD duration and systolic blood pressure (mm Hg) were chosen. In conclusion, rCBF decreased in all HD patients studied, irrespective of their clinical symptoms or MMSE scores. Blood pressure was an independent risk factor affecting the extent of decreased rCBF.