Study on epidemiology of cognitive dysfunction after stroke in the population over the age of 45 in Inner Mongolia.

OBJECTIVE: To analyze the prevalence of different degrees vascular cognitive impairment (VCI) in stroke and the characteristics of demography distribution in Inner Mongolia. In order to provide reference data and theoretical guidance for the prevention and treatment of VCI after stroke in the area. METHODS: Stratified multi-stage random sampling was used to extract six regions of Inner Mongolia as the first sampling cluster; and then the corresponding banners (counties) were selected randomly as the secondary sampling cluster; according to the number of patient required to investigation, the corresponding number of communities was randomly selected from the secondary sampling cluster. According to the diagnostic criteria of 'Guidelines for the diagnosis and treatment of vascular cognitive impairment' and National Institute of Neurological Disorders and Stroke convened an International Workshop with support from the Association Internationale pour la Recherche et l'Enseignement en Neurosciences (NINDS-AIREN), we screened all stroke patients aged 45 or older from each community, a total of 444 patients participated in the questionnaire and various scale assessments. RESULTS: The prevalence of VCI, vascular cognitive impairment no dementia and vascular dementia was 80.41%, 34.46% and 45.95% respectively. The prevalence of VCI in stroke was significantly different in different nationality, age and education level (P < 0.05), and there was no significant difference in gender, occupation, marital status and family structure (P > 0.05). CONCLUSION: The prevalence of VCI after stroke was higher in Inner Mongolia, and VCI had a relatively high morbidity in old age people and person with less education in Chinese Han population.

A Weighted Genetic Risk Score Based on Four APOE-Independent Alzheimer's Disease Risk Loci May Supplement APOE E4 for Better Disease Prediction.

Recent genome-wide association studies (GWAS) in European descent population have identified more than 30 independent single-nucleotide polymorphisms (SNPs) associated with Alzheimer's disease (AD). In the present study, we genotyped 39 AD-risk SNPs in 499 sporadic AD patients and 760 matched healthy controls of Mongolian ethnicity from the Inner Mongolia, China. Further, we investigated whether genetic risk score (GRS) combining multiple AD-risk loci confirmed in our study population could improve AD prediction. Two approaches were used for GRS calculation: a simple risk allele count (cGRS) and a weighted approach (wGRS). The area under the receiver operating characteristic curve (AUC) was used to compare the discriminatory ability of the GRS models. Seven SNPs were confirmed associated with AD and four SNPs were associated with AD risk independent of APOE genotypes in our population. GRS based on either seven SNPs or four APOE-independent SNPs were significantly associated with AD risk (P = 2.3E-17~2.0E-6). The AUC for wGRS was significantly greater than for cGRS (0.6416 versus 0.6339, P = 0.0049 for seven SNPs; 0.5857 versus 0.5765, P = 0.0047 for four APOE-independent SNPs). Furthermore, we found that wGRS combining four APOE-independent SNPs and APOE E4 genotypes reached AUC 0.7023, significantly better than the discriminate ability of APOE E4 genotypes alone (AUC = 0.6699, P = 0.0379). The combined model, with an AUC of 0.6989, significantly higher than that of APOE E4 alone (0.6529) (P = 0.0284), for subjects in a validation cohort comprising 250 cases and 380 controls, randomly selected from our original cohort. In summary, we found that wGRS based on four APOE-independent AD risk SNPs may supplement APOE E4 for better assessing individual risk for AD in Mongolian population in China.

Epidemiology Investigation of stroke among Mongolian and Han population aged over 45 in Inner Mongolia.

To discuss the status of epidemiology of stroke in the Mongolian and Han population aged over 45 years and to understand the treatment and prevention of stroke. Data collected on stroke populations aged over 45 years in the six areas in Inner Mongolia were analyzed by using stratified multi-stage cluster sampling. The prevalence rate of stroke in patients aged over 45 years in Inner Mongolia was 4.62%. The stroke prevalence rate increased with age in both males and females, the Han and Mongolian populations, and was higher in males than in females in Inner Mongolia. The prevalence rate of stroke in the Mongolian population was higher than in the Han population. The incidence rate of stroke in patients aged over 45 years in Inner Mongolia was 0.28%, of which the rate of relapsed ischemic stroke was 23.29%. The proportion of ischemic stroke in the stroke patients was higher than hemorrhagic stroke. The prevalence and incidence rates of stroke in patients aged over 45 years in Inner Mongolia were high. The prevalence rate of stroke in both the Han population and the Mongolian population increased with age. Ischemic stroke was the major form of stroke.