Risk for incident cancer rises with severity of obstructive sleep apnea
In a large cohort study of 33,000 participants, severity of obstructive sleep apnea was independently associated with incident cancer, according to data scheduled for presentation at the American Thoracic Society International Conference.
“Chronic hypoxemia and fragmented sleep are mechanisms by which obstructive sleep apnea is proposed to contribute to cancer development,” Tetyana Kendzerska, MD, PhD, associate scientist at The Ottawa Hospital and assistant professor in the division of respirology at University of Ottawa, Canada, said in a press release. “However, epidemiological evidence linking OSA and cancer is still inconclusive.”
Kendzerska and colleagues analyzed linked individual clinical and polysomnographic data from sleep clinics and provincial health administration databases from 1994 to 2017, in addition to information on cancer status and type from the Ontario Cancer Registry. For individuals free of cancer at the time of their sleep study, the researchers applied statistical analyses to examine OSA severity at the start of the study period and cancer development over time.
The cohort included 33,711 adults (median age, 59 years; 58% men). Of those, 23% had severe OSA, defined as apnea-hypopnea index of 30 or above.
During a median follow-up of 7 years, 7% of the cohort developed cancer (incidence rate, 10.3 per 1,000 person-years), according to the results.
Severe OSA was associated with a 15% increased risk for incident cancer compared with adults with no OSA (HR = 1.15; 95% CI, 1.02-1.3), after the researchers controlled for cancer risk factors and comorbidities at baseline. Severe nocturnal hypoxemia was associated with about a 30% greater risk for incident cancer (HR = 1.32; 95% CI, 1.08-1.61). The increased risk remained when the researchers controlled for BMI and sleep time.
The study also evaluated risk for specific cancer subtypes. Results showed OSA severity was associated with increased risk for incident colorectal and lung cancer.
“Knowledge of a patient’s risk will empower clinicians and patients to make informed decisions about treatment of OSA and may assist in advocating for better care and research into new therapies for OSA,” Kendzerska and colleagues wrote in the abstract.
Limitations of the study include its observational and historical design, and use of data from only four academic medical centers in Ottawa, according to the researchers.
Editor's note: This article was updated on June 24, 2020, to correct the percentage of patients with severe OSA, defined as apnea-hypopnea index of 30 or above.