The Case-control Study Of The Risk Factors In Elderly Cognitive Impairment

Obejective: 1. To investigate the relationshipe between vascular risk factors and mild cognitive impairment (MCI), Alzheimer's disease(AD) and vascular dementia(VD). 2. To explore whether cognitive impairment in MCI, AD and VD correlated with cerebrovascular lesions, brain white matter lesions (WML), cerebral atrophy and ventricular enlargement.Subjects and methods: The subjects were derived from consecutive registered cases in Chinese PLA General Hospital. The case-control study was carried out between MCI(n=97) and cognitive normal controls(NC, n=143), probable AD(n=95) and NC(n=143), probable VD(n=96) and NC(n=159) respectively. The cerebral CT images of MCI(n=70), AD(n=60), VD(n=60) and NC(n=84) were analyzed. The location and number of cerebrovascular lesions were detected. WML of CT scans were evaluated referenced the Wahlund(2001) rating scale. The linear measures of medial temporal lobe, regional temporal and frontal lobe, cerebral ventricles and fissures were made by assisting ImageJ software, including interuncal distance, interhemispheric fissure width, lateral fissure width, width of third ventricle, Huckman's value, ventricular index and width of lateral ventricular body index. T-test, Mann-Whitney U test, Pearson Chi-Square and Fisher's exact test for. univariate analysis, Logistic model for multivariate analysis. The level of statistical significance of differences in univariate and multivariate analysis was P<0.017, P<0.05 respectively.Results:1. The case-control study of risk factors of MCI: The history of coronary heart disease, stroke and anaemia were related to MCI, their OR (95% confidence interval, 95%CI)were 2.17( 1.17 ~ 4.03 ), 2.28( 1.26 ~ 4.13 ), 4.44( 1.75 ~ 11.28 ) respectively. MCI related with cerebrovascular lesions on brain CT scans, butnot WML, cerebral atrophy and ventricular enlargement. The OR was 6.63 (3.16-13.96) .2. The case-control study of risk factors of AD: The history of coronary heart disease, stroke and anaemia were risk factors of AD, their OR were 3.35( 1.75 ~6.42 ), 2.18( 1.22 ~ 3.91), 2.80( 1.04 ~ 7.52 )in turn. AD correlated with cerebrovascular lesions, interuncal distance and width of third ventricle measured by brain CT scans, their OR were 4.37 (1.72—11.09) ,1.51 (1.20—1.90) ,1.26(1.09—1.46) respectively. When cerebrovascular lesions were removed from Logistic model, WML total score was also related to AD, the OR was 1.24( 1.06— 1.46) .3. The case-control study of risk factors of VD: The history of hypertension, diabetes mellitus, coronary heart diseases and transient ischemic attack were risk factors of VD. Their OR were 3.45( 1.68 ~ 7.08 ), 2.62( 1.41 ~ 4.87 ), 2.30( 1.14 ~ 4.62 ), 2.23 ( 1.18 ~ 4.23 ) in order. WML total score in Logistic model, WML score of left frontal, width of third ventricle and left lateral fissure width associated with VD. Their OR were 1.53 (1.26—1.86), 4.13(2.19—7.79), 2.64 (1.74—4.00), 1.37 (1.06—1.76) respectively.Conclusion:1. The elderly cognitive impairment were correlated to vascular risk factors and cerebrovascular lesions founed on brain CT scans. The prevention and treatment of vascular diseases may improve the cognitive status of elder people.2. The atrophy of medial temporal lobe and left temporal lobe were significantly correlated to AD and VD respectively. Third ventricular enlargement and WML were significantly related to AD and VD.