Table 1

Baseline characteristics of study participants according to smoking status

Cohort INon-smokers (n=25)Cigarette smokers (n=26)Waterpipe smokers (n=12)Dual smokers (n=10)
Age (years)36.16±12.5246.73±9.9632.84±14.0439.5±12.49
 Male13 (52%)13 (50%)9 (69.24%)6 (60%)
 Female12 (48%)13 (50%)4 (30.76%)4 (40%)
Smoking status CS WPS
 Smoking frequency*N/A12.89±6.391.45±0.939.13±6.062.09±1.30
 Duration of smoking (years)†N/A20.03±8.552.72±1.8414.00±12.894.69±3.72
 Duration of smoking per session (minutes)‡N/AN/A15.00±15.17N/A16.40±16.55
Cohort II Non-smokers (n=24) Waterpipe smokers (n=33)
Age (years)25.9±4.4525.0±3.10
 Male11 (45.8%)16 (48.5%)
 Female13 (54.2%)17 (51.5%)
Smoking Status
 Smoking Frequency*N/A1.3±0.51
 Duration of smoking (years)†N/A4.20±3.32
  • Data are expressed as mean±SD or as the number of subjects (%).

  • All biological samples collected were not used for all biomarkers analysis. Number of subjects used for biomarkers analyses are given in parenthesis in Tables 2A and 2B.

  • *Average number of times subjects smoked cigarettes, waterpipe tobacco or both per day.

  • †Mean of numbers of years subjects have been smoking cigarettes, waterpipe tobacco or both.

  • ‡Average duration of each smoking session.

  • CS, cigarette smokers; N/A, not applicable; WPS, waterpipe tobacco smokers.