title: Long-term exposure to traffic-related PM(10) and decreased heart rate variability: is the association restricted to subjects taking ACE inhibitors?
abstract: BACKGROUND
  Alterations in heart rate variability (HRV) are a potential link between exposure to traffic-related air pollution and cardiovascular mortality.
  
  
  OBJECTIVE
  We investigated whether long-term exposure to traffic-related PM(10) (TPM(10)) is associated with HRV in older subjects and/or in participants taking specific cardiovascular treatment or with self-reported heart disease.
  
  
  METHODS
  We included 1607 subjects from the general population aged 50 to 72 years. These participants from the SAPALDIA cohort underwent ambulatory 24-hr electrocardiogram monitoring. Associations of average annual exposure to TPM(10) over 10 years with HRV parameters from time and frequency domains were estimated using multivariable mixed linear models. Effect estimates are expressed as percent changes in geometric means.
  
  
  RESULTS
  HRV was only associated with TPM(10) in participants under ACE inhibitor therapy (N=94). A 1 μg/m(3) increment, approximately equivalent to an interquartile range, in 10 year average TPM(10) was associated with decrements of 14.5% (95% confidence interval (CI), -25.9 to -1.3) in high frequency (HF) power, of 4.5% (-8.2 to -0.5) in the standard deviation of all normal-to-normal RR intervals (SDNN), of 10.6% (-18.5 to -1.9) in total power (TP) and an increase of 9.2% (0.8 to 20.2) in the LF/HF power ratio.
  
  
  CONCLUSIONS
  In the absence of an overall effect our results suggest that alterations in HRV, a measure of autonomic control of the cardiac rhythm, may not be a central mechanism by which long-term exposure to TPM(10) increases cardiovascular mortality. Novel evidence on an effect in persons under ACE inhibitor treatment needs to be confirmed in future studies.
authors: Swiss Tropical and Public Health Institute, Basel, Switzerland. martin.adam@unibas.ch
authors: Martin
authors: M
authors: Adam
authors: Denise
authors: D
authors: Felber Dietrich
authors: Emmanuel
authors: E
authors: Schaffner
authors: David
authors: D
authors: Carballo
authors: Jean-Claude
authors: JC
authors: Barthélémy
authors: Jean-Michel
authors: JM
authors: Gaspoz
authors: Ming-Yi
authors: MY
authors: Tsai
authors: Regula
authors: R
authors: Rapp
authors: Harish Chandra
authors: HC
authors: Phuleria
authors: Christian
authors: C
authors: Schindler
authors: Joel
authors: J
authors: Schwartz
authors: Nino
authors: N
authors: Künzli
authors: Nicole M
authors: NM
authors: Probst-Hensch
mesh_terms: D000368:Aged; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D001919:Bradycardia / Q000453:epidemiology; D005260:Female; D006331:Heart Diseases / Q000453:epidemiology; D006339:Heart Rate / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D019570:Inhalation Exposure / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D052638:Particulate Matter / Q000032:analysis*; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D000806:Angiotensin-Converting Enzyme Inhibitors; D052638:Particulate Matter; D001335:Vehicle Emissions