Effects of passive smoking on heart rate variability, heart rate and blood pressure: an observational study.
BACKGROUND
Exposure to environmental tobacco smoke (ETS) has been shown to increase the risk for cardiovascular diseases and death, and autonomic dysfunction (specifically, reduced heart rate variability (HRV)) is a predictor of increased cardiac risk. This study tests the hypothesis that ETS exposure reduces HRV in the general population and discusses possible pathways.


METHODS
This cross-sectional study was conducted between 2001 and 2003 and is part of the SAPALDIA (Swiss Cohort Study on Air Pollution and Lung Diseases in Adults) study. The analysis included 1218 randomly selected non-smokers aged 50 and above who participated in 24-h electrocardiogram recordings. Other examinations included an interview, investigating health status (especially respiratory and cardiovascular health and health relevant behaviours and exposure to ETS) and measurements of blood pressure, body height and weight.


RESULTS
Subjects exposed to ETS at home or at work for more than 2 h/day had a difference of -15% in total power (95%CI: -26 to -3%), low frequency power (-28 to -1%), low/high frequency ratio (-26 to -3%) and -18% (-29 to -4%) in ultralow frequency power of HRV compared with subjects not exposed to ETS at home or work. We also found a 2.7% (-0.01 to 5.34%) higher heart rate during the recording in exposed subjects.


CONCLUSIONS
Exposure to ETS at home and work is associated with lower HRV and with higher heart rate in an ageing population. Our findings suggest that exposure to ETS increases cardiac risk through disturbances in the autonomic nervous system.
Felber Dietrich
Denise
D
Institute of Social and Preventive Medicine, University of Basel, Switzerland. denise.felber@unibas.ch
Schwartz
Joel
J
Schindler
Christian
C
Gaspoz
Jean-Michel
JM
Barthélémy
Jean-Claude
JC
Tschopp
Jean-Marie
JM
Roche
Frédéric
F
von Eckardstein
Arnold
A
Brändli
Otto
O
Leuenberger
Philippe
P
Gold
Diane R
DR
Ackermann-Liebrich
Ursula
U
D001341:Autonomic Nervous System; D001794:Blood Pressure; D002318:Cardiovascular Diseases / Q000209:etiology; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D004522:Educational Status; D015716:Electrocardiography, Ambulatory; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D018570:Risk Assessment / Q000379:methods; D013557:Switzerland; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D014937:Work
D014028:Tobacco Smoke Pollution