Cardiac Sympathetic Nerve Activity among Passive Smokers and Smokeless Tobacco Users: A Cross-sectional Study

Abstract

Introduction: Tobacco use and exposure to Second-Hand Smoke (SHS) are major health hazards for growing children and adolescents. Smokeless Tobacco (SLT) product consumption is a serious health issue both abroad and in India. Children and young people are more likely to be exposed to Secondhand Smoke (SHS) in India due to high population density. Aim: To assess physical anthropometric parameters and cardiac autonomic function tests among passive smokers and SLT users. Materials and Methods: This cross-sectional study was conducted in the department of Physiology Nootan Medical College and Research Centre, Visnagar from August 2023 to February 2024. The study was comprised of 100 participants including 50 non-smokers who chew tobacco and who have never been a passive smoker in Group-A (SLT) and 50 age-matched passive smokers who lived with at least one smoker or frequently interacted with smokers at work for at least three years before conducting this study was included in Group-B (Passive smoke or SHS). Anthropometric measurements were recorded. Cardiac autonomic function tests were done by using a Polyrite recording machine with mode “ECG” in Lead-II position among both groups. Results were expressed as mean±Standard Deviation (SD), and analysed by using unpaired student’s t-test. The p-value of <0.05 was considered as statistically significant. Results: Resting (Basal) heart rate was significantly increased in the SLT group (p-value≤0.001). Resting Systolic Blood Pressure (SBP) was significantly reduced in the passive smoker group when compared to SLT group (p-value≤0.001). It was noted that 30:15 ratio was statistically significant in the passive smokers as compared to that in the SLT group (p-value≤0.001). It was also noted that blood pressure response to immediate standing in passive smokers was highly significant (p-value≤0.001). Conclusion: The results of present study showed that sympathetic activity was increased and parasympathetic activity was decreased in tobacco users (SLT). The fall of SBP in response to immediate standing among passive smokers is suggestive of decreased central sympathetic activity and baroreceptor reflex sensitivity.

Keywords

• cardiac autonomic function tests
• parasympathetic activity
• passive smoke