Maximum Oxygen Uptake Capacity of Smokers of Different Age Groups

抄録

Eighty-four healthy asymptomatic sedentary smokers and 92 healthy sedentary non-smokers of the age range 20-59 years were investigated for their maximum oxygen uptake capacity (V_O2max) and related cardiorespiratory parameters at the level of maximal exercise by bicycle ergometry. The subjects were blocked into four age decades of 20-29, 30-39, 40-49, and 50-59 years to show the effect of smoking on V_O2max of smokes of different age groups. The physical characteristics of smokers and non-smokers of comparable age groups did not show any significant difference. The smokers of each subsequent age group consumed 5.9±4.1, 6.3±5.7, 12.7±7.1, and 11.5±9.1 pack years of cigarettes, respectively (pack year=number of packets of cigarettes per day ×number of years of smoking). VO2max of smokers (38.9±4.6 ml•kg^-1•min^-1) was significantly lower (p<0.05) than that of nonsmokers (42.1±3.2ml•kg^-1•min^-1) only in the young age group of 20-29 years. V_O2max expressed in per kg of the body weight (V_O2max/BW) was found to be significantly (p<0.01) and negatively correlated with number of cigarettes smoked per day (-0.36, p<0.01), number of years through which smoked (-0.38, p<0.01), and pack years (-0.42, p<0.01). In other age groups, though non-smokers predominated over smokers in V_O2max, the differences were not statistically significant. Also, in these age groups, smoking histories failed to reveal any significant correlation with V_O2max. This suggests that smoking impairs V_O2max only in the young ages. By increasing age, V_O2max was diminished by 13% from 20 to 59years in non-smokers and 15.5% from 20 to 59years in smokers. Age also diminished HRmax and VEmax of smokers in the same manner as in the case of non-smokers. The V_O2max of Indian sedentary non-smokers was found to be lower than those of Caucasians, Kurds, Yemenites, Europeans, and Africans. Values reported on Asians were found to be comparable with those of the present study.