title: Exposure to particulate air pollution and long-term incidence of frailty after myocardial infarction.
abstract: OBJECTIVE
  Frailty, a multidimensional syndrome of increased vulnerability, is prevalent post-myocardial infarction (MI) and predicts mortality and recurrent events. We investigated whether chronic exposure to particulate matter ≤2.5 μm in diameter (PM2.5) is associated with the development of post-MI frailty.
  
  
  METHODS
  Participants (n = 1120) were aged 65 or less and admitted to hospital in central Israel with first MI in 1992 and 1993. Daily measures of PM2.5 recorded at air quality monitoring stations were summarized and chronic exposure was estimated individually using the geo-coded residential location. Frailty assessment was conducted via an index based on deficit accumulation, and those defined as frail (applying a threshold of ≥0.25) at baseline were excluded. Remaining participants who survived to follow-up 10 to 13 years post-MI (n = 848) were reassessed for frailty. Logistic regression models were constructed to evaluate the role of PM2.5 exposure in frailty risk prediction.
  
  
  RESULTS
  Mean exposure to PM2.5 was 24.2 μg/m(3) (range, 16.9-28.6). A total of 301 participants (35.5%) developed frailty during follow-up. Adjusting for sociodemographic and clinical variables, PM2.5 exposure was associated with increased odds of developing frailty (odds ratio, 1.53; 95% confidence interval, 1.22-1.91, comparing the 75th vs. 25th percentiles). Addition of PM2.5 exposure to the multivariable model resulted in an integrated discrimination improvement of 1.60% (P = .005) and a net reclassification index of 6.51% (P = .02).
  
  
  CONCLUSIONS
  An association was observed between exposure to PM2.5 and incidence of frailty, providing a potential intermediary between air pollution and post-MI outcomes.
authors.affiliation: Department of Epidemiology and Preventive Medicine, School of Public Health, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Vicki
authors.initials: V
authors.lastname: Myers
authors.forename: David M
authors.initials: DM
authors.lastname: Broday
authors.forename: David M
authors.initials: DM
authors.lastname: Steinberg
authors.lastname: Yuval
authors.forename: Yaacov
authors.initials: Y
authors.lastname: Drory
authors.forename: Yariv
authors.initials: Y
authors.lastname: Gerber
mesh_terms: D000368:Aged; D000393:Air Pollutants / Q000009:adverse effects*; D000397:Air Pollution / Q000009:adverse effects*; D004781:Environmental Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D007557:Israel / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology*; D052638:Particulate Matter / Q000009:adverse effects*; D012306:Risk; D012720:Severity of Illness Index
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter