Effect of Smoking on Heart Rate at Rest, During Exercise, and on Heart Rate Recovery in Young Males

Background and need of research: Smoking contributes to several respiratory diseases due to its hazardous effect on respiratory and circulatory system which ultimately affects cardiovascular system. HR is very important, non-invasive and easy-to-measure index of myocardial work. From this study, difference in heart rate can be identified at an early stage among smokers to prevent effects of smoking on cardiac system. Method: An Observational study was conducted in individuals of age between 18 to 45 years. 50 Male subjects who were smoking since more than 2 years, having normal BMI (18.5-22.9Kg/m2) according to Asian classification were included. Person with Severe Cardio respiratory disorder, neurological conditions, any fracture or musculoskeletal disorder which may hamper in step test were excluded. Subjects were divided into 2 groups: 1] Smokers and 2] Non-smokers.HR was measured at rest, during and post 5 minutes of Queens College Step Test to compare between both groups. Result: Mean age, BMI, HR rest, HR during exercise and post HR of smokers were (36.24±6.65), (22.09±0.7), (77.2±4.89), (120.96±5.54) and (90.16±5.72) and in non-smokers were (35.76±7.03), (21.78±1.1), (46.88±6.46), (139.16±8.17) and (73.92±5.9) respectively. Comparison was done using unpaired-t test, Smokers had significantly higher HR at rest, slower HR increase during exercise compared to non-smokers. During recovery, the HR decline was significantly attenuated in smokers. Conclusion and clinical implication: Smoking is found to affect young male smokers’ Heart Rate. Therefore, more actions should be taken to spread awareness about its harmful effects and smoking cessation, especially in young adults. Keywords: Smoking, Queens College Step Test, Heart Rate