Table 1.

Clinical characteristics of study subjects

Variable	Nonsmokers	Smokers
Total collected samples	126	177
Age (years; median ± average)	20±21	24±27
Body mass index
Obese (≥30)	20/100 (20%)	27/163 (17%)
Nonobese (<30)	80/100 (80%)	136/163 (83%)
Years of smoking
>5	–	104/165 (63%)
≤5	–	61/165 (37%)
Cigarettes per day
≥20	–	99/159 (62.3%)
<20	–	60/159 (37.7%)