Mortality from respiratory diseases associated with opium use: a population-based cohort study.

BACKGROUND: Recent studies have suggested that opium use may increase mortality from cancer and cardiovascular diseases. However, no comprehensive study of opium use and mortality from respiratory diseases has been published. We aimed to study the association between opium use and mortality from respiratory disease using prospectively collected data. METHODS: We used data from the Golestan Cohort Study, a prospective cohort study in northeastern Iran, with detailed, validated data on opium use and several other exposures. A total of 50 045 adults were enrolled from 2004 to 2008, and followed annually until June 2015, with a follow-up success rate of 99%. We used Cox proportional hazard regression models to evaluate the association between opium use and outcomes of interest. RESULTS: During the follow-up period, 331 deaths from respiratory disease were reported (85 due to respiratory malignancies and 246 due to non-malignant aetiologies). Opium use was associated with an increased risk of death from any respiratory disease (adjusted HR 95% CI 3.13 (2.42 to 4.04)). The association was dose-dependent with a HR of 3.84 (2.61 to 5.67) for the highest quintile of cumulative opium use versus never use (Ptrend<0.001). The HRs (95% CI) for the associations between opium use and malignant and non-malignant causes of respiratory mortality were 1.96 (1.18 to 3.25) and 3.71 (2.76 to 4.96), respectively. CONCLUSIONS: Long-term opium use is associated with increased mortality from both malignant and non-malignant respiratory diseases.

Opium use and risk of mortality from digestive diseases: a prospective cohort study.

OBJECTIVES: Opium use, particularly in low doses, is a common practice among adults in northeastern Iran. We aimed to investigate the association between opium use and subsequent mortality from disorders of the digestive tract. METHODS: We used data from the Golestan Cohort Study, a prospective cohort study in northeastern Iran, with detailed, validated data on opium use and several other exposures. A total of 50,045 adults were enrolled during a 4-year period (2004-2008) and followed annually until December 2012, with a follow-up success rate of 99%. We used Cox proportional hazard regression models to evaluate the association between opium use and outcomes of interest. RESULTS: In all, 8,487 (17%) participants reported opium use, with a mean duration of 12.7 years. During the follow-up period 474 deaths from digestive diseases were reported (387 due to gastrointestinal cancers and 87 due to nonmalignant etiologies). Opium use was associated with an increased risk of death from any digestive disease (adjusted hazard ratio (HR)=1.55, 95% confidence interval (CI)=1.24-1.93). The association was dose dependent, with a HR of 2.21 (1.57-3.31) for the highest quintile of cumulative opium use vs. no use (Ptrend=0.037). The HRs (95% CI) for the associations between opium use and malignant and nonmalignant causes of digestive mortality were 1.38 (1.07-1.76) and 2.60 (1.57-4.31), respectively. Increased risks were seen both for smoking opium and for ingestion of opium. CONCLUSIONS: Long-term opium use, even in low doses, is associated with increased risk of death from both malignant and nonmalignant digestive diseases.