Background
There is limited information about the hazards of cigarettes, smokeless tobacco, and waterpipe in the Middle East. The aim of this study was to determine the association between different types of tobacco use and earlier death in the Golestan Cohort Study.
Methods
The Study includes 50,045 adults (aged 40–75) from northeastern Iran. The baseline questionnaire (2004–2008) assessed information about use of cigarettes, chewing tobacco (nass), and waterpipe. To assess the use of each type of tobacco compared with never tobacco users, we used Cox regression models adjusted for age, socioeconomic status, area of residence, education, and other tobacco used, and stratified by sex, ethnicity, and opium use.
Results
17% of participants reported a history of cigarette smoking, 7.5% chewing tobacco (nass), and 1.1% smoking waterpipe, and these figures declined in the later birth cohorts. During a median follow-up of 8 years, 4,524 deaths occurred (mean age 64.8±9.9 years). Current (HR=1.44; 95%CI: 1.28–1.61) and former (HR=1.35; 95%CI: 1.16–1.56) cigarette smokers had higher overall mortality relative to never tobacco users. The highest cigarette-associated risk was for cancer death among current heavy smokers (HR=2.32; 95%CI: 1.66–3.24). Current nass chewing was associated with overall mortality (HR=1.16; 95%CI: 1.01–1.34), and there was a 61% higher risk of cancer death in people chewing nass more than 5 times a day. We observed an association between the cumulative lifetime waterpipe use (waterpipe-years>=28) and both overall (HR=1.66; 95%CI: 1.11–2.47), and cancer mortality (HR=2.82; 95%CI: 1.30–6.11).
Conclusions
Regular use of cigarettes, smokeless tobacco and waterpipe were associated with the risk of earlier death (particularly from cancer) in our cohort.