Non-apnea sleep disorders will increase subsequent liver cancer risk - A nationwide population-based cohort study

Introduction: It is well known that patients with sleep disorders (SD) have an increased risk of cardiovascular disease, diabetes mellitus, obesity, and total mortality. However, little information exists regarding the relationship between non-apnea SD and the risk of cancer. The goal of this study was to determine if any association between SD and malignancy exists in Taiwan. Methods: We used data from the National Health Insurance system of Taiwan to assess this issue. The SD cohort contained 42,351 patients, and each patient was randomly frequency-matched by age and sex with two people from the general population without SD. The Cox's proportional hazard regression analysis was conducted to estimate the effects of SD on cancer risk. Results: In patients with SD, the overall risk of developing cancer was significantly higher than in normal healthy subjects (adjusted Hazard ratio [HR] = 1.12, 95% confidence interval = 1.06-1.18). This held true even when we analyzed males and females separately. In regards to individual types of cancer, the risk for developing liver cancer among patients with SD was significantly higher than in subjects without SD. For breast cancer the risk showed a marginally significant increase. Conclusion: The nationwide population-based cohort study found Taiwanese patients with SD have a higher risk of developing cancer, particularly liver cancer and, possibly, breast cancer. (C) 2012 Elsevier B.V. All rights reserved.