Increased incidence of colorectal cancer with obstructive sleep apnea: a nationwide population-based cohort study

Background: Epidemiological studies on the obstructive sleep apnea (OSA) and cancer relationship in humans are inconsistent. Furthermore, there are limited prospective studies on the association between OSA and the risk of colorectal cancer (CRC). This retrospective cohort study examined the longitudinal relationship between OSA and CRC in a nationwide population-based cohort. Methods: We identified 4180 individuals newly diagnosed with OSA (the exposed cohort) and randomly selected 16,720 age- and sex-matched subjects without OSA (the nonexposed cohort) between 2000 and 2008 from Taiwan's National Health Insurance Research Database (NHIRD). The Kaplan-Meier method was used for calculating the cumulative incidence of CRC in each cohort. Cox proportional hazard regression models were used to estimate hazard ratios (HRs) and the accompanying 95% confidence intervals (CIs) for the association between OSA and CRC. Results: After adjusting for potential confounders, patients with OSA were associated with a significantly higher risk of CRC than those without OSA (adjusted HR, 1.80; 95% CI, 1.28-2.52). The cumulative incidence of CRC was significantly higher in the OSA cohort than in the comparison cohort (log-rank test, p < 0.001). Furthermore, the association between OSA and CRC appeared to be enhanced with increasing frequency of OSA medical visits (adjusted HR [95% CI] was 1.61 [0.97-2.66] and 1.86 [1.26-2.75] for one visit and two or more visits, respectively). Conclusion: This population-based cohort study demonstrated that OSA was associated with an increased risk of CRC. Further large-scale prospective studies are needed to confirm our results. (C) 2019 Published by Elsevier B.V.