title: Residential proximity to major roadways and renal function.
abstract: BACKGROUND
  Living near major roadways has been associated with increased risk of cardiovascular events, but little is known about its impact on renal function.
  
  
  METHODS
  We calculated the estimated glomerular filtration rate (eGFR) for 1103 consecutive Boston-area patients hospitalised with confirmed acute ischaemic stroke between 1999 and 2004. We used linear regression to evaluate the association between eGFR and categories of residential distance to major roadway (0 to ≤50, >50 to ≤100, >100 to ≤200, >200 to ≤400, >400 to ≤1000 and >1000 m) adjusting for age, sex, race, smoking, comorbid conditions, treatment with ACE inhibitor and neighbourhood-level socioeconomic characteristics. In a second analysis, we considered the log of distance to major roadway as a continuous variable.
  
  
  RESULTS
  Patients living closer to a major roadway had lower eGFR than patients living farther away (Ptrend=0.01). Comparing patients living 50 m versus 1000 m from a major roadway was associated with a 3.9 ml/min/1.73 m(2) lower eGFR (95% CI 1.0 to 6.7; p=0.007): a difference comparable in magnitude to the reduction in eGFR observed for a 4-year increase in age in population-based studies. The magnitude of this association did not differ significantly across categories of age, sex, race, history of hypertension, diabetes or socioeconomic status.
  
  
  CONCLUSIONS
  Living near a major roadway is associated with lower eGFR in a cohort of patients presenting with acute ischaemic stroke. If causal, these results imply that exposures associated with living near a major roadway contribute to reduced renal function, an important risk factor for cardiovascular events.
authors.affiliation: Cardiovascular Epidemiology Research Unit, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.
authors.forename: Shih-Ho
authors.initials: SH
authors.lastname: Lue
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Wellenius
authors.forename: Elissa H
authors.initials: EH
authors.lastname: Wilker
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Mostofsky
authors.forename: Murray A
authors.initials: MA
authors.lastname: Mittleman
mesh_terms: D000368:Aged; D000397:Air Pollution / Q000009:adverse effects*; D001900:Boston; D002545:Brain Ischemia / Q000175:diagnosis; D003430:Cross-Sectional Studies; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006760:Hospitalization / Q000706:statistics & numerical data; D006798:Housing; D006801:Humans; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D051437:Renal Insufficiency / Q000150:complications* / Q000503:physiopathology / Q000652:urine; D012111:Residence Characteristics; D012307:Risk Factors; D012959:Socioeconomic Factors; D020521:Stroke / Q000175:diagnosis; D014505:Urban Population
keywords: AIR POLLUTION; EPIDEMIOLOGY; VASCULAR DISEASE