Sleep-disordered Breathing and Cancer Mortality

Abstract

Rationale: Sleep-disordered breathing (SDB) has been associated with total and cardiovascular mortality, but an association with cancer mortality has not been studied. Results from in vitro and animal studies suggest that intermittent hypoxia promotes cancer tumor growth. Objectives: The goal of the present study was to examine whether SDB is associated with cancer mortality in a community-based sample. Methods: We used 22-year mortality follow-up data from the Wisconsin Sleep Cohort sample (n ¼ 1,522). SDB was assessed at baseline with full polysomnography. SDB was categorized using the apnea-hypopnea index (AHI) and the hypoxemia index (percent sleep time below 90% oxyhemoglobin saturation). The hazards of cancer mortality across levels of SDB severity were compared using crude and multivariate analyses. Measurements and Main Results: Adjusting for age, sex, body mass index, and smoking, SDB was associated with total and cancer mortality in a dose-response fashion. Compared with normal subjects, the adjusted relative hazards of cancer mortality were 1.1 (95% confidence interval [CI], 0.5-2.7) for mild SDB (AHI, 5-14.9), 2.0 (95% CI, 0.7-5.5) for moderate SDB (AHI, 15-29.9), and 4.8 (95% CI, 1.7-13.2) for severe SDB (AHI > 30) (P-trend ¼ 0.0052). For categories of increasing severity of the hypoxemia index, the corresponding relative hazards were 1.6 (95% CI, 0.6-4.4), 2.9 (95% CI, 0.9-9.8), and 8.6 (95% CI, 2.6-28.7). Conclusions: Our study suggests that baseline SDB is associated with increased cancer mortality in a community-based sample. Future studies that replicate our findings and look at the association between sleep apnea and survival after cancer diagnosis are needed.Keywords: cancer; cohort study; mortality; obstructive sleep apnea; sleep-disordered breathing Sleep disordered breathing (SDB) is characterized by recurrent episodes of total or partial obstruction of the upper airway (apnea or hypopnea) during sleep that are associated with intermittent hypoxemia, repeated sleep disruption, and snoring (1). The prevalence of moderate to severe SDB has been estimated to be as high as 6% among U.S. adults and rising as the prevalence of obesity, a major risk factor for SDB, continues to increase (2-4). SDB is associated with a variety of psychopathological disorders (depression, reduced quality of life) and increased risk of occupational and motor vehicle injuries, as well as with a variety of cardiovascular disease outcomes, hypertension, and the metabolic syndrome (3, 5, 6). These associations have been explained by the profound metabolic and sympathetic system disruption associated with repeated hypoxemic events (6, 7).Chronic hypoxia, a common feature in solid tumor tissue, has been associated with therapeutic resistance, tumor progression, and metastatic potential (8-10). In vitro studies have further demonstrated that cultured lung cancer cells subject to intermittent hypoxia are more resistant to radiation and apoptosis and are more prone to metastasis (11).Recent results from a study using a mouse...

Obstructive Sleep Apnea during REM Sleep and Hypertension. Results of the Wisconsin Sleep Cohort

“…These adverse effects of OSA are important mediators of cardiovascular risk (3,4), even in milder forms of OSA (5)(6)(7)(8). OSA has been independently associated with hypertension (9,10), coronary heart disease, stroke, and cardiovascular mortality (11)(12)(13)(14)(15).…”

AACR Cancer Progress Report 2013

“…In addition, recent studies indicate that sleep apnea, which is a well-established risk factor for cardiovascular mortality, is also linked with increased cancer mortality (44).…”

Metabolic syndrome, insulin resistance and sleepiness in real-life obstructive sleep apnoea

“…Conversely, the study by SASANABE et al [15] reported dyslipidaemia as the third most frequent finding. Finally, population-based studies yielded a prevalence of metabolic syndrome in OSA of between 26% and 35% [29][30][31]. A recent population study reported a 44% prevalence of metabolic syndrome in females with AHI .15 events?h -1 [32].…”