Sleep-Disordered Breathing and Cancer Mortality: The Wisconsin Study

Does sleep-disordered breathing have a connection with cancer mortality? A 2012 analysis of the Wisconsin Sleep Cohort reported an association. It is an important research finding, but it does not establish that snoring causes cancer or that reducing snoring prevents cancer deaths.

What did the researchers study?

Nieto and colleagues analysed 1,522 participants using 22 years of mortality follow-up. Baseline overnight sleep studies assessed breathing disturbances. The apnea–hypopnea index (AHI) counted breathing events per hour; a separate hypoxemia index measured the percentage of sleep time spent below 90% oxygen saturation.

What did they find?

After adjustment for age, sex, body mass index and smoking, greater sleep-disordered breathing severity was associated with greater cancer mortality. For severe disease (AHI at least 30), the adjusted hazard ratio was 4.8 compared with the reference group, with a wide 95% confidence interval of 1.7–13.2. The authors called for replication and further research.

How should you interpret the result?

A hazard ratio compares rates over follow-up; it is not an individual probability of dying from cancer. The wide confidence interval indicates considerable uncertainty about the size of the association. Statistical adjustment also cannot establish cause and effect or remove every possible influence.

This was an observational analysis, not a trial assigning people to treatment. It cannot demonstrate that treating sleep apnea prevents cancer deaths. Nor should findings about measured breathing disturbances and low oxygen be applied automatically to ordinary snoring.

What does this mean if you snore?

Frequent loud snoring, witnessed breathing pauses, gasping and daytime sleepiness are reasons to discuss possible sleep apnea with a healthcare professional. A sleep study may be needed. These symptoms do not, by themselves, indicate cancer. See our guide to snoring symptoms that need assessment.

Is this evidence about Asonor?

No. This study did not test Asonor. It provides no basis for claiming that Asonor prevents cancer, reduces cancer mortality or treats sleep apnea. An improvement in snoring sound should not be interpreted as proof that breathing disturbances have resolved.

Sources

• Nieto FJ and colleagues. Sleep-disordered Breathing and Cancer Mortality: Results from the Wisconsin Sleep Cohort Study. American Journal of Respiratory and Critical Care Medicine, 2012;186:190–194.
• NHLBI: Sleep apnea symptoms and when to seek assessment

Editorial update: September 2026. This article explains one historical study; it is not a systematic review of all research on sleep apnea and cancer.