Long-term opiate use and risk of cardiovascular mortality: Results from the Golestan Cohort Study

Aims: Tens of millions of people worldwide use opiates but little is known about their potential role in causing cardiovascular diseases. We aimed to study the association of long-term opiate use with cardiovascular mortality and whether this association is independent of the known risk factors. Methods and results: In the population-based Golestan Cohort Study - 50 045 Iranian participants, 40-75 years, 58% women - we used Cox regression to estimate hazard ratios and 95% confidence intervals (HRs, 95% CIs) for the association of opiate use (at least once a week for a period of 6 months) with cardiovascular mortality, adjusting for potential confounders - i.e. age, sex, education, wealth, residential place, marital status, ethnicity, and tobacco and alcohol use. To show independent association, the models were further adjusted for hypertension, diabetes, waist and hip circumferences, physical activity, fruit/vegetable intake, aspirin and statin use, and history of cardiovascular diseases and cancers. In total, 8487 participants (72.2% men) were opiate users for a median (IQR) of 10 (4-20) years. During 548 940 person-years - median of 11.3 years, >99% success follow-up - 3079 cardiovascular deaths occurred, with substantially higher rates in opiate users than non-users (1005 vs. 478 deaths/100 000 person-years). Opiate use was associated with increased cardiovascular mortality, with adjusted HR (95% CI) of 1.63 (1.49-1.79). Overall 10.9% of cardiovascular deaths were attributable to opiate use. The association was independent of the traditional cardiovascular risk factors. Conclusion: Long-term opiate use was associated with an increased cardiovascular mortality independent of the traditional risk factors. Further research, particularly on mechanisms of action, is recommended.