3. Results
3.1. General characteristics of study participants
We enrolled 201 subjects who completed the baseline inter- view and clinical exam. However, 21 subjects (about 10%) failed to complete the second and third interviews for various reasons. Participants' general information is shown in Table 1. No differences were observed between those who completed the two follow-up investigations (180 subjects) and those who were lost in the follow-ups (21 subjects) (data not shown). 103 female participants (57.2%) and 77 male participants (42.8%) completed all three interviews. 46% of subjects were older than 50 years of age,
33% of subjects have education of primary school or lower.
15 subjects (8.3%) had a BMI greater than 28. Of all subjects, 60 (33.3%) were active smokers including 55 males (71.4%) and
5 female (4.9%).