title: A U-shaped Association Between Blood Pressure and Cognitive Impairment in Chinese Elderly.
abstract: OBJECTIVE
  Higher or lower blood pressure may relate to cognitive impairment, whereas the relationship between blood pressure and cognitive impairment among the elderly is not well-studied. The study objective was to determine whether blood pressure is associated with cognitive impairment in the elderly, and, if so, to accurately describe the association.
  
  
  METHODS
  Cross-sectional data from the sixth wave of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) conducted in 2011.
  
  
  METHODS
  Community-based setting in longevity areas in China.
  
  
  METHODS
  A total of 7144 Chinese elderly aged 65 years and older were included in the sample.
  
  
  METHODS
  Systolic blood pressures (SBP) and diastolic blood pressures (DBP) were measured, pulse pressure (PP) was calculated as (SBP) - (DBP) and mean arterial pressures (MAP) was calculated as 1/3(SBP) + 2/3(DBP). Cognitive function was assessed via a validated Mini-Mental State Examination (MMSE).
  
  
  RESULTS
  Based on the results of generalized additive models (GAMs), U-shaped associations were identified between cognitive impairment and SBP, DBP, PP, and MAP. The cutpoints at which risk for cognitive impairment (MMSE <24) was minimized were determined by quadratic models as 141 mm Hg, 85 mm Hg, 62 mm Hg, and 103 mm Hg, respectively. In the logistic models, U-shaped associations remained for SBP, DBP, and MAP but not PP. Below the identified cutpoints, each 1-mm Hg decrease in blood pressure corresponded to 0.7%, 1.1%, and 1.1% greater risk in the risk of cognitive impairment, respectively. Above the cutpoints, each 1-mm Hg increase in blood pressure corresponded to 1.2%, 1.8%, and 2.1% greater risk of cognitive impairment for SBP, DBP, and MAP, respectively.
  
  
  CONCLUSIONS
  A U-shaped association between blood pressure and cognitive function in an elderly Chinese population was found. Recognition of these instances is important in identifying the high-risk population for cognitive impairment and to individualize blood pressure management for cognitive impairment prevention.
authors.affiliation: Institute of Environmental Health and Related Products Safety, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Yue-Bin
authors.initials: YB
authors.lastname: Lv
authors.affiliation: Institute of Environmental Health and Related Products Safety, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Peng-Fei
authors.initials: PF
authors.lastname: Zhu
authors.affiliation: Division of Non-Communicable Disease Control and Community Health, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Zhao-Xue
authors.initials: ZX
authors.lastname: Yin
authors.affiliation: Duke Molecular Physiology Institute and Division of Rheumatology, Department of Medicine, Duke University School of Medicine, Durham, NC.
authors.forename: Virginia Byers
authors.initials: VB
authors.lastname: Kraus
authors.affiliation: Division of Epidemiology, JC School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Diane
authors.initials: D
authors.lastname: Threapleton
authors.affiliation: Health Services and Systems Research, Duke-NUS Graduate Medical School, Singapore, Singapore.
authors.forename: Choy-Lye
authors.initials: CL
authors.lastname: Chei
authors.affiliation: Department of Sociology and Anthropology, Department of Human Development and Family Studies, University of Rhode Island, Kingston, RI.
authors.forename: Melanie Sereny
authors.initials: MS
authors.lastname: Brasher
authors.affiliation: Division of Non-Communicable Disease Control and Community Health, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Vanderbilt Institute for Global Health, Division of Epidemiology, Department of Medicine, Vanderbilt University, Nashville, TN.
authors.forename: Han-Zhu
authors.initials: HZ
authors.lastname: Qian
authors.affiliation: Division of Epidemiology, JC School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Mao
authors.affiliation: Health Services and Systems Research, Duke-NUS Graduate Medical School, Singapore, Singapore; Division of General Internal Medicine, Department of Medicine, Duke University School of Medicine, Durham, NC.
authors.forename: David Bruce
authors.initials: DB
authors.lastname: Matchar
authors.affiliation: Division of Non-Communicable Disease Control and Community Health, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Jie-Si
authors.initials: JS
authors.lastname: Luo
authors.affiliation: Center for the Study of Aging and Human Development and the Geriatric Division of School of Medicine, Duke University, Durham, NC; Center for Study of Healthy Aging and Development Studies, Peking University, Beijing, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zeng
authors.affiliation: Institute of Environmental Health and Related Products Safety, Chinese Center for Disease Control and Prevention, Beijing, China. Electronic address: shixm@chinacdc.cn.
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Shi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002681:China; D003072:Cognition Disorders / Q000209:etiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications* / Q000523:psychology*; D007022:Hypotension / Q000150:complications* / Q000523:psychology*; D008137:Longitudinal Studies; D008297:Male; D012307:Risk Factors
keywords: Blood pressure; cognitive impairment; curvilinear association; elderly; hypertension; hypotension