Dose-response association seen with risk of cancer mortality increases with severity of apnea
MONDAY, May 21 (HealthDay News) -- Obstructive sleep apnea (OSA) is associated with an increased risk of cancer mortality, according to a study presented at the annual meeting of the American Thoracic Society, held from May 18 to 23 in San Francisco.
Noting that intermittent hypoxia promotes tumor growth in a melanoma mouse model, F. Javier Nieto, M.D., Ph.D., from the University of Wisconsin in Madison, and colleagues investigated the association between OSA and cancer mortality using 20-year mortality follow-up data from 1,522 participants in the Wisconsin Sleep Cohort sample. Full polysomnography was used at baseline to assess OSA in all participants. The mean number of apnea and hypopnea events per hour of sleep was used to define the apnea-hypopnea index (AHI), and participants were classified as either normal (AHI <5), mild OSA (AHI 5 to 14.9), moderate OSA (AHI 15 to 29.9), or severe OSA (AHI ≥30 or use of continuous positive airway pressure).
The researchers found that, after adjustment for age, sex, body mass index, and smoking, all-cause and cancer mortality were associated with the severity of OSA in a dose-response manner. Compared to individuals without OSA, the adjusted hazard ratios were 1.1, 2.0, and 4.8 for those with mild, moderate, and severe OSA, respectively. The corresponding hazard ratios for increasing hypoxemia were 1.6, 2.9, and 8.6.
"Ours is the first study to show an association between sleep disordered breathing and an elevated risk of cancer mortality in a population-based sample," Nieto said in a statement. "Additional studies are needed to replicate our results and to examine the relationships between sleep disordered breathing, obesity, and cancer mortality."