Impact of GST Polymorphisms and Passive Smoking on Heart Health
Author Information
Author(s): Probst-Hensch Nicole M., Imboden Medea, Dietrich Denise Felber, Barthélemy Jean-Claude, Ackermann-Liebrich Ursula, Berger Wolfgang, Gaspoz Jean-Michel, Schwartz Joel
Primary Institution: University of Zürich
Hypothesis
Oxidative stress alters cardiac autonomic control, affecting heart rate variability (HRV) in nonsmokers exposed to second-hand smoke (SHS) and obesity.
Conclusion
GST deficiency is linked to significant alterations in heart rate variability, particularly in individuals exposed to second-hand smoke and those who are obese.
Supporting Evidence
- Homozygous GSTT1 null genotypes showed a 10% decrease in heart rate variability.
- Obese individuals with GSTM1 null genotypes had a 22% lower total power in heart rate variability.
- Participants exposed to more than 2 hours of second-hand smoke had a 26% reduction in heart rate variability.
Takeaway
This study found that people who have certain genetic traits and are exposed to second-hand smoke or are obese may have a harder time with their heart's rhythm.
Methodology
The study involved 1,133 nonsmokers over 50 years old who underwent 24-hour electrocardiogram monitoring and were genotyped for GSTM1, GSTT1, and GSTP1 polymorphisms.
Potential Biases
Potential biases may arise from self-reported SHS exposure and the cross-sectional nature of the study.
Limitations
The study's cross-sectional design limits the ability to establish causation, and the low prevalence of high SHS exposure may limit the power of gene-environment interaction analyses.
Participant Demographics
52% of participants were female, with a mean age of 60.6 years and a mean BMI of 26.6 kg/m2.
Statistical Information
P-Value
0.006
Confidence Interval
95% CI, 11 to 39%
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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