Obstructive sleep apnea is associated with cancer mortality in younger patients

Objective: The association between obstructive sleep apnea (OSA) and cancer mortality has scarcely been studied. The objective of this study was to investigate whether OSA is associated with increased cancer mortality in a large cohort of patients with OSA suspicion. Methods: This was a multicenter study in consecutive patients investigated for suspected OSA. OSA severity was measured by the apnea-hypoppea index (AHI) and the hypoxemia index (% night-time spent with oxygen saturation <90%, TSat(90)). The association between OSA severity and cancer mortality was assessed using Cox's proportional regression analyses after adjusting for relevant confounders. Results: In all, 5427 patients with median follow-up of 4.5 years were included. Of these, 527(9.7%) were diagnosed with cancer. Log-transformed TSat(90) was independently associated with increased cancer mortality in the entire cohort (hazard ratio [HR], 1.21; 95% confidence interval [CI], 1.03-1.42), as well as in the group of patients with cancer (HR, 1.19; 95% CI, 1.02-1.41). The closest association was shown in patients <65 years in both the AHI (continuous log-transformed AHI: HR, 1.87; 95% CI, 1.1-3.2; upper vs lower AHI tertile: HR, 3.98; 95% CI, 1.14-3.64) and the TSat(90) (continuous log-transformed TSat(90): HR, 1.73; 95% CI, 1.23-2.4; upper vs lower TSat(90) tertile: HR, 14.4; 95% CI, 1.85-111.6). Conclusions: OSA severity was associated with increased cancer mortality, particularly in patients aged <65 years. (C) 2014 Elsevier B.V. All rights reserved.