title: The influence of multimorbidity on clinical progression of dementia in a population-based cohort.
abstract: BACKGROUND
  Co-occurrence with other chronic diseases may influence the progression of dementia, especially in case of multiple chronic diseases. We aimed to verify whether multimorbidity influenced cognitive and daily functioning during nine years after dementia diagnosis compared with the influence in persons without dementia.
  
  
  METHODS
  In the Kungsholmen Project, a population-based cohort study, we followed 310 persons with incident dementia longitudinally. We compared their trajectories with those of 679 persons without dementia. Progression was studied for cognition and activities of daily life (ADLs), measured by MMSE and Katz Index respectively. The effect of multimorbidity and its interaction with dementia status was studied using individual growth models.
  
  
  RESULTS
  The mean (SD) follow-up time was 4.7 (2.3) years. As expected, dementia related to both the decline in cognitive and daily functioning. Irrespective of dementia status, persons with more diseases had significantly worse baseline daily functioning. In dementia patients having more diseases also related to a significantly faster decline in daily functioning. Due to the combination of lower functioning in ADLs at baseline and faster decline, dementia patients with multimorbidity were about one to two years ahead of the decline of dementia patients without any co-morbidity. In persons without dementia, no significant decline in ADLs over time was present, nor was multimorbidity related to the decline rate. Cognitive decline measured with MMSE remained unrelated to the number of diseases present at baseline.
  
  
  CONCLUSIONS
  Multimorbidity was related to baseline daily function in both persons with and without dementia, and with accelerated decline in people with dementia but not in non-demented individuals. No relationship of multimorbidity with cognitive functioning was established. These findings imply a strong interconnection between physical and mental health, where the greatest disablement occurs when both somatic and mental disorders are present.
authors.affiliation: Department of Geriatric Medicine/Radboud Alzheimer Centre, Radboud University Medical Centre, Nijmegen, The Netherlands.
authors.forename: René J F
authors.initials: RJ
authors.lastname: Melis
authors.affiliation: Department of Medical and Surgery Sciences, University of Brescia, Brescia, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Marengoni
authors.affiliation: Aging Research Center/Department of Neurobiology, Care Sciences and Society, Karolinska Institutet and Stockholm University, Stockholm, Sweden.
authors.forename: Debora
authors.initials: D
authors.lastname: Rizzuto
authors.affiliation: Department of Health Evidence, Radboud University Medical Centre, Nijmegen, The Netherlands.
authors.forename: Steven
authors.initials: S
authors.lastname: Teerenstra
authors.affiliation: Aging Research Center/Department of Neurobiology, Care Sciences and Society, Karolinska Institutet and Stockholm University, Stockholm, Sweden.
authors.forename: Miia
authors.initials: M
authors.lastname: Kivipelto
authors.affiliation: Aging Research Center/Department of Neurobiology, Care Sciences and Society, Karolinska Institutet and Stockholm University, Stockholm, Sweden.
authors.forename: Sara B
authors.initials: SB
authors.lastname: Angleman
authors.affiliation: Aging Research Center/Department of Neurobiology, Care Sciences and Society, Karolinska Institutet and Stockholm University, Stockholm, Sweden.
authors.forename: Laura
authors.initials: L
authors.lastname: Fratiglioni
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D003071:Cognition; D015331:Cohort Studies; D015897:Comorbidity; D003704:Dementia / Q000453:epidemiology* / Q000503:physiopathology; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male