Renovascular disease and cognitive impairment in elderly: a novel risk maker

ABSTRACT

Renal artery stenosis is most commonly due to either fibromuscular dysplasia or atherosclerosis. Atherosclerosis accounts for 90 percent of cases of renal-artery stenosis. Renal-artery stenosis may occur alone [isolated anatomical renal-artery stenosis] or in association with hypertension, renal insufficiency [ischemic nephropathy], or both. The aim of the present work was to study the role of renovascular disease as a novel risk marker of cognitive impairment in elderly. The study included 80 patients divided into 4 groups Group 1 20 cases of elderly patients above 65 years and suffering from grade 2 or 3 CKD. Group II 20 cases aged 20-40 years and suffering from grade 2 or 3 CKD. Group III 20 healthy controls aged above 65 years. Group IV 20 healthy controls aged 20-40. They had been evaluated for their Clinical condition, including physical examination and history taking, ECG, BMI estimation, MMMS examination, Routine investigation including complete blood picture with differential counting, bleeding and coagulation time, liver functions tests, lipid profile, fasting and post-prandial plasma glucose, renal function tests, complete urine analysis, 24-hours proteins in urine, assessment of glomerular filtration rate [GFR] by MDRD and creatinine clearance and in addition specific laboratory investigations were done including Serum CRP using turbidimetry, Microalbuminurea using turbidimetry, v-WF Ag by ELISA, s-ICAM. By ELISA and Duplex study was performed on carotid and renal arteries. The results of the present study showed that there was a significant increase in the BMI in groups land II in comparison to group III which was higher than group IV. The MMMS test was significantly lower in group I in comparison to groups II and III which were in turn significantly lower than group IV. Hemoglobin was significantly lower in groups I and II than group III and IV. Platelets count was significantly lower in groups I and II than group III which was also significantly lower than group IV. Creatinine clearance was significantly lower in groups I and II than in groups III and IV vWF levels were significantly lower in groups land II than in groups III and IV s.ICAM I was significantly higher in groups I and II compared to groups Ill and IV. CRP was significantly increased in groups I and II in comparison to groups III and IV Carotid plaque score was significantly higher in group I than group II which was higher than groups III. Resistive index was significantly lower in groups land II than in groups III and IV Acceleration index was significantly lower in groups I and II than in groups III and IV. A significant positive correlation was found between age and urinary albumin, CRP, and s.ICAM. A significant negative correlation between age and cereatinine clearance and MDRD in groups I, II and III. Reno vascular disease is common in elderly and the most important cause is atherosclerosis in this group of patients. There are many risk factors for cognitive impairment in patients suffering from renovascular disease and most of them are correctable. Renovascular disease can be considered as a novel risk factor of cognitive impairment through many interacting mechanisms