title: Association Between Lifestyle Factors and the Incidence of Multimorbidity in an Older English Population.
abstract: BACKGROUND
  Evidence on the role of lifestyle factors in relation to multimorbidity, especially in elderly populations, is scarce. We assessed the association between five lifestyle factors and incident multimorbidity (presence of ≥2 chronic conditions) in an English cohort aged ≥50 years.
  
  
  METHODS
  We used data from waves 4, 5, and 6 of the English Longitudinal Study of Ageing. Data on smoking, alcohol consumption, physical activity, fruit and vegetable consumption, and body mass index were extracted and combined to generate a sum of unhealthy lifestyle factors for each individual. We examined whether these lifestyle factors individually or in combination predicted multimorbidity during the subsequent wave. We used marginal structural Cox proportional hazard models, adjusted for both time-constant and time-varying factors.
  
  
  RESULTS
  A total of 5,476 participants contributed 232,749 person-months of follow-up during which 1,156 cases of incident multimorbidity were recorded. Physical inactivity increased the risk of multimorbidity by 33% (adjusted hazard ratio [aHR]: 1.33, 95% confidence interval [CI]: 1.03-1.73). The risk was about two to three times higher when inactivity was combined with obesity (aHR: 2.87, 95% CI: 1.55-5.31) or smoking (aHR: 2.35, 95% CI: 1.36-4.08) and about four times when combined with both (aHR: 3.98, 95% CI: 1.02-17.00). Any combination of 2, 3, and 4 or more unhealthy lifestyle factors significantly increased the multimorbidity hazard, compared with none, from 42% to 116%.
  
  
  CONCLUSIONS
  This study provides evidence of a temporal association between combinations of different unhealthy lifestyle factors with multimorbidity. Population level interventions should include reinforcing positive lifestyle changes in the population to reduce the risk of developing multimorbidity.
authors.affiliation: Diabetes Research Centre, University of Leicester, UK.
authors.forename: Nafeesa N
authors.initials: NN
authors.lastname: Dhalwani
authors.affiliation: Diabetes Research Centre, University of Leicester, UK.
authors.forename: Francesco
authors.initials: F
authors.lastname: Zaccardi
authors.affiliation: Diabetes Research Centre, University of Leicester, UK.
authors.forename: Gary
authors.initials: G
authors.lastname: O'Donovan
authors.affiliation: Department of Public Health and Primary Care, University of Cambridge, UK.
authors.forename: Patrice
authors.initials: P
authors.lastname: Carter
authors.affiliation: National Centre for Sport and Exercise Medicine, Loughborough University, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Hamer
authors.affiliation: Diabetes Research Centre, University of Leicester, UK.
authors.forename: Thomas
authors.initials: T
authors.lastname: Yates
authors.affiliation: Diabetes Research Centre, University of Leicester, UK.
authors.forename: Melanie
authors.initials: M
authors.lastname: Davies
authors.affiliation: Diabetes Research Centre, University of Leicester, UK.
authors.forename: Kamlesh
authors.initials: K
authors.lastname: Khunti
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D008019:Life Style; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged
keywords: Multimorbidity; Nutrition; Obesity; Physical activity; Smoking