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 (GCS), 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 nonmalignant etiologies). Opium use was associated with an increased risk of death from any respiratory disease (adjusted hazard ratio (HR) 95% CI; 3.13 (2.42-4.04)). The association was dose-dependent with a HR of 3.84 (2.61-5.67) for the highest quintile of cumulative opium use vs. never use (Ptrend<0.001). The hazard ratios (95% CI) for the associations between opium use and malignant and nonmalignant causes of respiratory mortality were 1.96 (1.18-3.25) and 3.71 (2.76-4.96), respectively.
Conclusion
Long-term opium use is associated with increased mortality from both malignant and nonmalignant respiratory diseases.