A Comparative Histological Study of Submucosal Gland Hypertrophy in Trachea of Mice Exposed to Cigarette and Shisha Smoke.

OBJECTIVE To observe the effects of Shisha smoke on submucosal glands of trachea of mice; and compare it with tracheal glands of mice exposed to cigarette smoke. STUDY DESIGN Randomised controlled trial. PLACE AND DURATION OF STUDY Department of Anatomy, Islamic International Medical College, Rawalpindi, in collaboration with National Institute of Health (NIH), Islamabad from October 2013 till April 2014. METHODOLOGY Sample comprised of 40 adult male mice of strain BALB/c. They were randomly divided into three groups. Control group was labelled as Group 'C'. The mice in this group were kept in a whole body smoke exposure chamber and were exposed to fresh air. Shisha group was labelled as Group 'SS', and the mice in this group were exposed to Shisha smoke. Mice in the third group labelled as Group CS were exposed to cigarette smoke. All the mice were dissected after an exposure period of eight weeks. Tracheal tissue was stained and examined microscopically for submucosal gland hypertrophy and compared with the control group, using Reid's Index. An Index of more than 0.4 is termed as hypertrophy. RESULTS There was significant submucosal gland hypertrophy in groups CS and SS as compared to group C. There was also significant difference in the frequency of mucosal hypertrophy between SS (93.7%) and CS groups (53.3%), which was found statistically significant (p<0.001). CONCLUSION Shisha smoking was significantly associated with mucosal hypertrophy when compared with cigarette smoking and controls. Shishasmoke contains higher level of toxicants as compared to cigarette smoke, and it causes more oxidative damage of tissues.