Study On Correlation Between Cardiovascular Risk Factors And Cognitive Impairment In Elderly Hypertensive Patients

Background:With the rapid development of global population aging, the health problems of theelderly increasingly attracted people’s attention, especially the prevalence of dementia.Survey shows that there were2.42million Alzheimer’s patients in2005worldwide, whichis expected to quadruple by2050. Each year about4.6million new patients will bediagnosed.In China, dementia incidence rate of person65years of age or older is5-10%,and this data is growing rapidly with the passage of time. As we all know, cognitiveimpairment is an early clinical manifestation and characteristics of dementia. Effectivecontrol of early risk factors can significantly delay the onset of cognitive dysfunction andimprove the quality of life of older persons.It has been widely recognized by the community of scientists and medical attentionthat hypertension is an important independent risk factor for cardiovascular andcerebrovascular disease, which can cause target organ damage as stroke, hypertensiveheart disease, heart failure, chronic renal insufficiency. Especially in the elderly people, hypertension is a major risk factor of cardiovascular disease mortality. However, theimpact of hypertension on cognitive function has not yet attracted enough attention by theacademic community, despite the famous Framingham Heart Study found that bloodpressure and cognitive function scores were negatively correlated. However, because ofthe complexity of the different sample populations, cognitive function, design and the useof different survey tools, conclusions on cognitive function in patients with hypertensionrisk factors are different. To this end, we intend to explore the risk factors related tocognitive dysfunction in elderly hypertensive patients, and whom with differentstratification of cardiovascular risk factors and cognitive dysfunction relevance. It isexpected to provide a research basis with a view to preventing and delaying earlycognitive impairment in elderly patients with hypertension.Objective:Through cross-sectional samples survey on the health status of the elderly in Xi’an, therisk factors of cognitive function in elderly patients with hypertension were discussed; thecorrelation between different stratification of cardiovascular risk factors and cognitivedysfunction was investigated.Methods:During December2011to June2013,747old people aged60years and older in Xi’an(Xijing Hospital, Xi’an Jiaotong University and community) were recruited by randomcluster sampling method. According to the diagnostic criteria of hypertension, patientswere divided into hypertensive patients and normotensive patients and conducted aquestionnaire survey. The survey included demographic characteristics, the prevalence ofchronic disease, behavior and social life functional assessment, MMSE and secondaryinspection, which reflected the health of elderly patients in Xi’an. SPSS18.0wasstatistically analyzed. MMSE score in elderly hypertensive patients was analyzed bymultiple linear regression analysis. Risk factors of hypertensive patients and cognitiveimpairment in elderly hypertensive patients was analyzed by multivariate logisticregression analysis. Results：1. General demographic characteristics in elderly hypertensive patients and elderlynormotensive patients:747older people were included in this study. There are329hypertensive patients and418normotensive patients. In hypertension group, there are185men accounting for43.94%of the total number of males and144women accounting for44.17%of the total number of females. In normotensive group, there are236menaccounting for56.06%of the total number of males and182women accounting for55.83%of the total number of females. As10years as an age group, the samples ofhuman divided into60-69,70-79,80years and older. In all age hypertensive groupsconstituent ratio is39.41%,42.65%,59.38%respectively, while constituent ratio tonormotensive group in each age group is60.59%,57.35%,40.63%. Education level inXi’an elderly is mainly college or university degree. Most older people still dwell inmarriage. Occupational status analysis indicated that the largest elderly people were theadministrative cadre officers. The elderly people have good marital status and the numberof households is up to two couples. Elderly before retired mainly engaged in mental work.2. The condition of chronic diseases in elderly hypertensive patients and elderlynormotensive patients: The top five prevalence rate of chronic diseases in the elderly arehypertension (329cases), coronary heart disease (228cases), osteoarthritis (135cases), cataract (110cases), diabetes (108cases).The percentage of the top fiveillnesses between the two groups are44.04%and55.96%,66.79%and34.21%,37.04%and62.96%,44.55%and55.45%,68.52%and31.48%.3. Cognitive function in elderly hypertensive patients and elderly normotensivepatients: MMSE score in hypertensive group (26.51±4.752) is significantly lower thannormotensive group (28.16±3.390)(P<0.05). Age and blood urea nitrogen arenegatively related to the MMSE score(P<0.05). Education level, engaged in intellectualwork, the law of life, often doing housework, and actively participating in social activitiescan improve the patient’s MMSE score, but gender is not the impact of the MMSEscore(P>0.05).4. Auxiliary examination in elderly hypertensive patients and elderly normotensive patients: Values of systolic blood pressure, diastolic blood pressure, fasting glucose,2-hour postprandial blood glucose, creatinine, urea nitrogen in the elderly hypertensivepatients are higher than elderly normotensive patients. They are respectively141.37±19.90and129.67±19.31,82.34±21.27and75.44±10.80,6.61±6.82and5.60±4.32,8.92±3.77and7.41±2.71,96.29±37.46and90.94±35.80,6.21±5.38and5.36±3.81.They are statistically different in the two groups（P<0.05）.5. Lifestyle in elderly hypertensive patients and elderly normotensive patients:246people in elderly patients do physical exercise2-3hours per day, including84elderlyhypertensive patients (34.15%) and162elderly normotensive patients (65.85%).528elderly patients is smoking, including229elderly hypertensive patients (43.37%) and299elderly normotensive patients (56.63%).590elderly patients like drinking, containing250elderly hypertensive patients (42.37%) and340elderly normotensive patients(57.63%). Most elderly have better eating habits and intake more balance.449elderlypatients sleep6-8hours daily, including190elderly hypertensive patients (42.32%) and259elderly normotensive patients (57.68%). Sleep quality of328elderly patients isnormal, including147elderly hypertensive patients (44.82%) and181elderlynormotensive patients (55.18%).396elderly patients often do housework, including158elderly hypertensive patients (39.90%) and238elderly normotensive patients (60.10%).380elderly patients do not participate in social activities, including198elderlyhypertensive patients (52.11%) and182elderly normotensive patients (47.89%).6. Relationship between risk stratification and cognitive function in elderlyhypertensive patients: With the increase of the degree of vascular risk, disorientation,memory, recall, attention, language skills and MMSE score are decreased from low riskgroup, risk group, high-risk groups, and very high-risk groups in order. There arestatistically different in the two groups (P<0.05).7. Factors of cognitive function in elderly hypertensive patients: Elderly hypertensivepatients according to MMSE score are divided into normal cognitive function group andcognitive dysfunction group. The results of cognitive stratification between different riskfactors and associated factors in the two groups show: age, occupation, physical exercise, housework, participating in social activities, stroke, cerebrovascular disease are thecognitive factors.8. The condition of auxiliary examination in cognitive function of elderlyhypertensive patients: In elderly hypertensive patients, triglyceride in cognitivedysfunction group is higher than normal cognitive function. The difference wasstatistically significant (P <0.05). While the body mass index, diastolic blood pressure,systolic blood pressure, fasting glucose, two-hour postprandial blood glucose, cholesterol,uric acid in the blood and carotid artery intima-media thickness are not statisticallydifferent in two groups（P>0.05）.Conclusion：1. Increasing age, history of coronary heart and cerebrovascular disease, notparticipating in social activities, increasing of2h postprandial hyperglycemia are the riskfactors for hypertension in elderly, while the high level of education and good sleep habitsare protective factors in elderly patients with hypertension.2. MMSE score in elderly hypertensive patients are positively correlated witheducation, engaged in mental work, housework, participate in public welfareactivities,while it is negatively correlated with age and blood urea nitrogen levels. Aging,poor physical exercise, not doing housework and participating in social activities are theimportant risk factors for cognitive impairment in elderly hypertensive patients.3. Disorientation, memory, recall, attention, language skills and MMSE score inelderly hypertensive patients will reduce with cardiovascular risk factors and stratificationincreasing.