title: Comorbidity and dementia: A nationwide survey in Taiwan.
abstract: BACKGROUND
  Comorbid medical diseases are highly prevalent in the geriatric population, imposing hardship on healthcare services for demented individuals. Dementia also complicates clinical care for other co-existing medical conditions. This study investigated the comorbidities associated with dementia in the elderly population aged 65 years and over in Taiwan.
  
  
  METHODS
  We conducted a nationwide, population-based, cross-sectional survey; participants were selected by computerized random sampling from all 19 Taiwan counties between December 2011 and March 2013. After exclusion of incomplete or erroneous data, 8,456 subjects were enrolled. Of them, 6,183 were cognitively normal (control group), 1,576 had mild cognitive impairment (MCI), and 697 had dementia. We collected information about types of comorbidities (i.e., vascular risk factors, lung diseases, liver diseases, gastrointestinal diseases, and cancers), Charlson comorbidity index score, and demographic variables to compare subjects with normal cognition, MCI, and dementia.
  
  
  RESULTS
  Regardless of the cognitive condition, over 60% of the individuals in each group had at least one comorbid disease. The proportion of subjects possessing at least three comorbidities was higher in those with cognitive impairment (MCI 20.9%, dementia 27.3%) than in control group (15%). Hypertension and diabetes mellitus were the most common comorbidities. The mean number of comorbidities and Charlson comorbidity index score were greater in MCI and dementia groups than in control group. Logistic regression demonstrated that the comorbidities significantly associated with MCI and dementia were cerebrovascular disease (OR 3.35, CI 2.62-4.28), cirrhosis (OR 3.29, CI 1.29-8.41), asthma (OR 1.56, CI 1.07-2.27), and diabetes mellitus (OR 1.24, CI 1.07-1.44).
  
  
  CONCLUSIONS
  Multiple medical comorbid diseases are common in older adults, especially in those with cognitive impairment. Cerebrovascular disease, cirrhosis, asthma, and diabetes mellitus are important contributors to cognitive deterioration in the elderly. Efforts to lower cumulative medical burden in the geriatric population may benefit cognitive function.
authors.affiliation: Department of Neurology, Neurological Institute, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Ting-Bin
authors.initials: TB
authors.lastname: Chen
authors.affiliation: Department of Biostatistics, Columbia University Mailman School of Public Health, New York, NY, United States of America.
authors.forename: Szu-Yu
authors.initials: SY
authors.lastname: Yiao
authors.affiliation: Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan.|Department of Neurology, En Chu Kong Hospital, New Taipei City, Taiwan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Taiwan Alzheimer's Disease Association, Taipei, Taiwan.
authors.forename: Huey-Jane
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: Taiwan Alzheimer's Disease Association, Taipei, Taiwan.
authors.forename: Shu-Chien
authors.initials: SC
authors.lastname: Yang
authors.affiliation: Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan.|Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei, Taiwan.|Graduate Institute of Psychology, College of Science, National Taiwan University, Taipei, Taiwan.
authors.forename: Ming-Jang
authors.initials: MJ
authors.lastname: Chiu
authors.affiliation: Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Ta-Fu
authors.initials: TF
authors.lastname: Chen
authors.affiliation: Department of Psychology, Soo-Chow University, Taipei, Taiwan.|Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Ker-Neng
authors.initials: KN
authors.lastname: Lin
authors.affiliation: Taiwan Alzheimer's Disease Association, Taipei, Taiwan.
authors.forename: Li-Yu
authors.initials: LY
authors.lastname: Tang
authors.affiliation: Department of Computer Science and Information Engineering, Chung Gung University, Tao-Yuan, Taiwan.
authors.forename: Chung-Chih
authors.initials: CC
authors.lastname: Lin
authors.affiliation: Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.|Department of Neurology, National Yang-Ming University School of Medicine, Taipei, Taiwan.|Aging and Health Research Center, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Pei-Ning
authors.initials: PN
authors.lastname: Wang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003704:Dementia / Q000453:epidemiology*; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D012044:Regression Analysis; D013624:Taiwan / Q000453:epidemiology