Characteristic Smokers (n=24) Non-smokers(n=24) Women(n=12) Men(n=12) Women(n=12) Men(n=12) Age (mean)           39.5 42.5 33.5 38.5 Pack/day of smoking (mean) 1.21 1.21     Years smoked (mean) 19.83 21.67     Age at start of smoking (mean) 18.67 20.83

Note: Age and smoking status of the study population presented were not significant (p<0.05). The level of significance of age between smokers and non-smokers of both sexes, the p-vale of smoking status depending on years smoked, number of cigarettes smoked and the age of starting smoking between male and female smokers are presented in SI Table 1.

Table 1: Summary of study population characteristics.