Sleep apnea increased incidence of primary central nervous system cancers: a nationwide cohort study

Prevalence of obstructive sleep apnoea syndrome in oncological patients: A systematic review and meta-analysis

BACKGROUND

Obstructive sleep apnoea syndrome (OSAS) has garnered increasing attention in recent years due to its potential association with cancer. This systematic review and meta-analysis aimed to assess the prevalence of OSAS in cancer patients through a comprehensive analysis of existing literature.

METHODS

This systematic review and meta-analysis, conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol, aimed to evaluate the prevalence of OSAS in cancer patients. A comprehensive search of electronic databases was performed to identify relevant studies published up to September 2021. Eligible studies reporting on the prevalence of OSAS in cancer patients, encompassing various study designs, were included in the analysis. Pooled estimates of the odds ratios (OR) with 95% confidence intervals (CIs) were calculated using a random effects model. Heterogeneity among the studies was assessed using the I2 statistic.

RESULTS

Seventeen studies fulfilled the inclusion criteria and were subsequently included in the review. The prevalence of OSAS in cancer patients was estimated to have an overall OR of 0.80 (95% CI: 0.75-0.85). In comparison with non-cancer patients, cancer patients had a statistically significant greater risk of OSAS, as indicated by the total estimated RR for the prevalence of OSAS in cancer patients, which was 0.89 (95% CI: 0.86-0.92). Nonetheless, there was a significant amount of heterogeneity (I2 = 96%) among the studies.

CONCLUSION

The overall data analysed in this review indicates that patients with cancer had far reduced likelihood of developing OSAS than individuals without cancer. However, the significant variation across the included studies highlights the need for additional investigation to fully clarify the complex association between OSAS and cancer incidence. These results emphasise how critical it is to identify OSAS as a possible comorbidity in cancer patients, one that should be taken into account for clinical management and ongoing research.

Cognitive complaints in patients with untreated obstructive sleep apnea versus patients with neurological and respiratory diseases: prevalence, severity and risk factors

PURPOSE

Little is known about cognitive complaints (self-reported problems in cognitive functioning) in patients with Obstructive Sleep Apnea (OSA). We compared the prevalence and severity of cognitive complaints in patients with untreated OSA to patients with neurological and respiratory diseases. We also studied risk factors for cognitive complaints across these diseases, including OSA.

METHODS

We used a convenience sample to compare untreated OSA patients (N = 86) to patients with stroke (N = 166), primary brain tumor (N = 197) and chronic obstructive pulmonary disease (COPD, N = 204) on cognitive complaints (Cognitive Failure Questionnaire, CFQ), anxiety and depression (Hospital Anxiety and Depression Scale, HADS) and cognitive impairments using neuropsychological tests. We combined all patient groups (OSA, stroke, brain tumor and COPD) and studied potential risk factors (demographic variables, anxiety, depression and cognitive impairments) for cognitive complaints across all patient groups using regression analysis.

RESULTS

The prevalence of cognitive complaints was higher in OSA patients and complaints of forgetfulness and distractibility were more severe compared to stroke and primary brain tumor patients, but similar to or lower than COPD patients. Regression analysis for the combined sample of all patient groups showed that cognitive complaints were most strongly associated with symptoms of anxiety and depression.

CONCLUSION

A high rate of OSA reported clinically significant cognitive complaints, comparable to other respiratory and neurological patients. Symptoms of anxiety and depression are important risk factors for cognitive complaints in patients with various neurological and respiratory diseases. Future studies should examine the relation between anxiety, depression and cognitive complaints in patients with OSA.

Does OSA Increase Risk for Cancer?: A Large Historical Sleep Clinic Cohort Study

BACKGROUND

The relationship between OSA and cancer is unclear.

RESEARCH QUESTION

What is the association between OSA and cancer prevalence and incidence in a large Western Australian sleep clinic cohort (N = 20,289)?

STUDY DESIGN AND METHODS

OSA severity was defined by apnea-hypopnea index (AHI) and nocturnal hypoxemia (duration and percentage at oxygen saturation < 90%) measured by in-laboratory polysomnogram. Measures of potential confounding included age, sex, BMI, smoking status, socioeconomic status, and BP. Outcomes were determined from the Western Australian cancer and death registries. Analyses were confined within periods using consistent AHI scoring criteria: January 1, 1989, to July 31, 2002 (American Sleep Disorders Association criteria), and August 1, 2002, to June 30, 2013 (Chicago criteria). We examined associations of AHI and nocturnal hypoxemia with cancer prevalence using logistic regression and cancer incidence using Cox regression analyses.

RESULTS

Cancer prevalence at baseline was 329 of 10,561 in the American Sleep Disorders Association period and 633 of 9,728 in the Chicago period. Nocturnal hypoxemia but not AHI was independently associated with prevalent cancer following adjustment for participant age, sex, BMI, smoking status, socioeconomic status, and BP. Of those without prevalent cancer, cancer was diagnosed in 1,950 of 10,232 (American Sleep Disorders Association) and 623 of 9,095 (Chicago) participants over a median follow-up of 11.2 years. Compared with the reference category (no OSA, AHI < 5 events per hour), univariable models estimated higher hazard ratios for cancer incidence for mild (AHI 5-15 events per hour), moderate (AHI 15.1-30 events per hour), and severe (AHI > 30 events per hour) OSA. Multivariable analyses consistently revealed associations between age and, in some cases, sex, BMI, and smoking status, with cancer incidence. After adjusting for confounders, multivariable models showed no independent association between OSA severity and increased cancer incidence.

INTERPRETATION

Nocturnal hypoxemia is independently associated with prevalent cancer. OSA severity is associated with incident cancer, although this association seems secondary to other risk factors for cancer development. OSA is not an independent risk factor for cancer incidence.

Self-reported sleep disorders and the risk of all cancer types: evidence from the Kailuan Cohort study

OBJECTIVES

Previous studies that focussed on sleep disturbance have primarily examined specific aspects of sleep disorders rather than considering overall sleep quality. We aimed to investigate different sleep disorders and their combination as risk factors for different types of cancer.

STUDY DESIGN

Prospective cohort study.

METHODS

In this prospective cohort study, we included 78,232 participants. A self-reported questionnaire was used to address insomnia, daytime sleepiness, snoring, and sleep duration. Overall sleep quality was evaluated by summarising these four sleep parameters. Cox proportional hazards analysis was used to estimate the hazard ratios and their 95% confidence intervals for determining the effect of the overall sleep-quality score and its components on the risk of incident cancer.

RESULTS

During a median follow-up of 5.67 years, 1266 participants were diagnosed with incident cancer. Compared to participants in the best sleep-quality score group, participants in the worst sleep-quality score group had a higher subsequent risk of overall cancer, and colorectal, breast, uterine or uterine cervical, prostatic, kidney, and bladder cancer. Participants with insomnia and snoring status had an elevated risk of head and neck, breast, uterine or uterine cervical, prostatic, kidney, bladder cancer, and lymphoma.

CONCLUSIONS

Poor overall sleep-quality scores as well as poor scores for the scale's components, including insomnia and snoring status, elevated the risk of overall and several specific-site cancers.

TRIAL REGISTRATION

Kailuan Study, ChiCTR2000029767. Registered 12 February, 2020-Retrospectively registered, https://www.chictr.org.cn/showprojEN.html?proj=48316.

Intermittent hypoxia BMSCs-derived exosomal miR-31-5p promotes lung adenocarcinoma development via WDR5-induced epithelial mesenchymal transition

BACKGROUND

Intermittent hypoxia (IH) is a factor involved in the incidence and progression of lung adenocarcinoma (LUAD). Bone marrow-derived bone mesenchymal stem cells (BMSCs)-derived exosomes are related to the promotion of tumor development. The objective of this experiment was to clarify the mechanism of exosomes from BMSCs in promoting the progression of LUAD induced by IH.

METHODS

This study examined if IH BMSCS-derived exosomes affect the malignancy of LUAD cells in vitro. Dual-luciferase assays were conducted to confirm the target of miR-31-5p with WD repeat domain 5 (WDR5). We further investigated whether or not  exosomal miR-31-5p or WDR5 could regulate epithelial-mesenchymal transition (EMT). We determined the effect of IH exosomes using a tumorigenesis model in vivo.

RESULTS

miR-31-5p entered into LUAD cells via exosomes. MiR-31-5p was greatly upregulated in IH BMSCs-derived exosomes compared with RA exosomes. Increased expression of exosomal miR-31-5p induced by IH was discovered to target WDR5 directly, increased activation of WDR5, and significantly facilitated EMT, thereby promoting LUAD progression.

CONCLUSIONS

The promoting effect of IH on LUAD is achieved partly through BMSCs-derived exosomal miR-31-5p triggering WDR5 and promoting EMT.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

The Burden of Comorbidities in Obstructive Sleep Apnea and the Pathophysiologic Mechanisms and Effects of CPAP

Micro-arousals and the repeated desaturation of oxyhemoglobin, which are typical in obstructive sleep apnea syndrome (OSAS), have adverse effects on the health of patients, leading to a wide range of complications such as cardiovascular (arterial hypertension, pulmonary hypertension, chronic heart failure, arrhythmias, myocardial infarction), cerebrovascular (strokes), metabolic (insulin resistance, obesity, diabetes mellitus, metabolic syndrome), gastrointestinal (non-alcoholic liver disease), urinary (chronic renal failure), and neuropsychiatric complications as well as a wide range of malignancies. These, in turn, have multilateral effects on familial, occupational, and social life, as well as increasing the risks of road traffic accidents and accidents at the workplace. Awareness, timely screening, and the prevention of complications play important roles in diagnosing and treating comorbid conditions. This review focuses on comorbidities in OSAS and the effect of Continuous Positive Airway Pressure (CPAP) therapy on their prognoses.

Association of Smoking and Respiratory Disease History with Pancreatic Pathologies Requiring Surgical Resection

BACKGROUND

The purpose of this study was to examine the relationship between various respiratory conditions, including hypercapnic respiratory disease, and a multitude of resected pancreatic lesions.

METHODS

This retrospective case-control study queried a prospectively maintained database of patients who underwent pancreaticoduodenectomy between January 2015 and October 2021. Patient data, including smoking history, medical history, and pathology reports, were recorded. Patients with no smoking history and no concomitant respiratory conditions were designated as the control group.

RESULTS

A total of 723 patients with complete clinical and pathological data were identified. Male current smokers showed increased rates of PDAC (OR 2.33, 95% CI 1.07-5.08, p = 0.039). Male patients with COPD had a markedly increased association with IPMN (OR 3.02, CI 1.08-8.41, p = 0.039), while females with obstructive sleep apnea had a four-fold increase in risk of IPMN compared to women in the control group (OR 3.89, CI 1.46-10.37, p = 0.009). Surprisingly, female patients with asthma had a decreased incidence of pancreatic and periampullary adenocarcinoma (OR 0.36, 95% CI 0.18-0.71. p < 0.01).

CONCLUSION

This large cohort study reveals possible links between respiratory pathologies and various pancreatic mass-forming lesions.

Association between obstructive sleep apnoea and cancer: a cross-sectional, population-based study of the DISCOVERY cohort

OBJECTIVES

Nocturnal hypoxia in obstructive sleep apnoea (OSA) is a potential risk factor for cancer. We aimed to investigate the association between OSA measures and cancer prevalence in a large national patient cohort.

DESIGN

Cross-sectional study.

SETTINGS

44 sleep centres in Sweden.

PARTICIPANTS

62 811 patients from the Swedish registry for positive airway pressure (PAP) treatment in OSA, linked to the national cancer registry and national socioeconomic data (the course of DIsease in patients reported to Swedish CPAP, Oxygen and VEntilator RegistrY cohort).

OUTCOME MEASURES

After propensity score matching for relevant confounders (anthropometric data, comorbidities, socioeconomic status, smoking prevalence), sleep apnoea severity, measured as Apnoea-Hypopnoea Index (AHI) or Oxygen Desaturation Index (ODI), were compared between those with and without cancer diagnosis up to 5 years prior to PAP initiation. Subgroup analysis for cancer subtype was performed.

RESULTS

OSA patients with cancer (n=2093) (29.8% females, age 65.3 (SD 10.1) years, body mass index 30 (IQR 27-34) kg/m²) had higher median AHI (n/hour) (32 (IQR 20-50) vs 30 (IQR 19-45), n/hour, p=0.002) and median ODI (n/hour) (28 (IQR 17-46) vs 26 (IQR 16-41), p<0.001) when compared with matched OSA patients without cancer. In subgroup analysis, ODI was significantly higher in OSA patients with lung cancer (N=57; 38 (21-61) vs 27 (16-43), p=0.012)), prostate cancer (N=617; 28 (17-46) vs 24, (16-39)p=0.005) and malignant melanoma (N=170; 32 (17-46) vs 25 (14-41),p=0.015).

CONCLUSIONS

OSA mediated intermittent hypoxia was independently associated with cancer prevalence in this large, national cohort. Future longitudinal studies are warranted to study the potential protective influence of OSA treatment on cancer incidence.

Risk of cancer in patients with insomnia: Nationwide retrospective cohort study (2009-2018)

PURPOSE

To investigate the association between insomnia and the risk of various cancers using the Korean National Health Insurance Service database.

MATERIALS AND METHODS

Patients who underwent a national health examination in 2009 were followed-up until 2018. Newly-diagnosed cancers were collected one year after the baseline. Insomnia was defined as having a diagnosis of F510 or G470 within one year prior to enrollment. The incidence of various cancers was compared between patients with and without insomnia.

RESULTS

In the overall study population (N = 3,982,012), the risk for any type of cancer was not different between controls and insomnia patients (adjusted hazard ratio [aHR]: 0.990). However, it was different by age; insomnia increased the risk of any cancer in younger age groups (20-39y and 40-59y, aHR:1.310 and 1.139, respectively) but it significantly decreased the risk in the 60-79y age group (aHR: 0.939). In cancer type, colorectal cancer risk was lower (aHR: 0.872, P < 0.0001), whereas leukemia risk was higher (aHR: 1.402, P < 0.0001) in patients with insomnia than in those without it, regardless of sex. In men, the risk of stomach cancer was lower (aHR: 0.882, P = 0.0003), and the risks of lung (aHR:1.114, P = 0.0005), kidney (aHR 1.226, P = 0.0107), and prostate (aHR:1.101, P = 0.0028) cancers were higher in insomnia patients than in control patients. In women, insomnia patients compared to control patients showed a lower risk of ovarian cancer (aHR:0.856, P = 0.0344, respectively), while they had a higher risk of oral (aHR:1.616, P = 0.002), thyroid (aHR:1.072, P = 0.0192), and nerve (aHR: 1.251, P = 0.016) cancers.

CONCLUSION

Insomnia is associated with an increased or decreased risk of some cancers, depending on age, cancer type and sex.

Effects of Surgical Treatment for Obstructive Sleep Apnea on Renal and Survival Outcomes in Patients with Chronic Kidney Disease: A Taiwanese Nationwide Cohort Study

The association between surgical treatment for obstructive sleep apnea (OSA) in chronic kidney disease (CKD) patients and end-stage renal disease (ESRD) and survival outcomes is not established, and this study aimed to evaluate this association. A retrospective cohort analysis was conducted from 2001 to 2015, including 32,220 eligible CKD patients with incident OSA. By 1:3 propensity score matching, 1078 CKD patients with incident OSA who received surgery (treated cohort) and 3234 untreated cohort who never received surgery were analyzed. The risk of ESRD in the competing mortality was significantly lower in the treated cohort than in the untreated cohort, with an adjusted hazard ratio (aHR) of 0.38 (95% confidence interval (CI0, 0.15−0.97; p = 0.043). In addition, the adjusted HRs of overall, cardiovascular, and non-cardiovascular mortality in the treated and untreated cohorts were 2.54 (95% CI, 1.79−3.59; p < 0.0001), 1.46 (95% CI, 0.29−7.22; p = 0.64), and 2.62 (95% CI, 1.83−3.75; p < 0.0001), respectively. Furthermore, the risks of overall and non-cardiovascular mortality for the treated cohort primarily occurred during a 3-month follow-up. In conclusion, surgical treatment for incident OSA in CKD patients was associated with decreased ESRD risk, but with increased non-cardiovascular mortality risk, especially within 3 months after surgical treatment.

Surveillance of long-term complications after treatment of adult brain tumor survivors—review and evidence-based recommendations

AbstractAs a result of treatment and diagnosis, adults with primary or metastatic brain tumors experience comorbidities that impacts their health and well-being. The Children’s Oncology Group has guideline recommendations for childhood survivors of brain tumors; however, guidelines for monitoring long-term sequela among adult brain tumor survivors are lacking. The purpose of this review is to present the screening recommendations for the long-term complications after brain tumor treatment from a multidisciplinary panel of healthcare professionals. Chronic complications identified include cognitive dysfunction, vasculopathy, endocrinopathy, ophthalmic, ototoxicity, physical disability, sleep disturbance, mood disorder, unemployment, financial toxicity, and secondary malignancy. We invited specialists across disciplines to perform a literature search and provide expert recommendations for surveillance for long-term complications for adult brain tumor survivors. The Brain Tumor Center Survivorship Committee recommends routine screening using laboratory testing, subjective assessment of symptoms, and objective evaluations to appropriately monitor the complications of brain tumor treatments. Effective monitoring and treatment should involve collaboration with primary care providers and may require referral to other specialties and support services to provide patient-centered care during neuro-oncology survivorship. Further research is necessary to document the incidence and prevalence of medical complications as well as evaluate the efficacy of screening and neuro-oncology survivorship programs.

Association of obstructive sleep apnea and nocturnal hypoxemia with all-cancer incidence and mortality: a systematic review and meta-analysis

STUDY OBJECTIVES

Biological models suggest that obstructive sleep apnea (OSA) is potentially carcinogenic. We aimed to clarify the inconsistent epidemiological literature by considering various traditional and novel OSA severity indices.

METHODS

We systematically searched PubMed, Embase, Scopus, and the Cochrane Library for observational or randomized studies of associations of OSA, measured by diagnostic codes or any index, each with all-cancer incidence or mortality in adults, compared with participants with no/mild OSA. Two reviewers independently selected studies, extracted data, and evaluated study bias using the Newcastle-Ottawa scale and quality of evidence using GRADE (Grading of Recommendations Assessment, Development, and Evaluation). We performed inverse variance-weighted, random-effects meta-analyses and sensitivity analyses.

RESULTS

We included 20 observational studies (5,340,965 participants), all with moderate/low bias, from 1,698 records. Based on T90 (sleep duration with oxygen saturation < 90%), patients with OSA who had moderate (T90 > 1.2%, hazard ratio [HR] = 1.28, 95% confidence interval [CI] = 1.07-1.54) and severe nocturnal hypoxemia (T90 > 12%, HR = 1.43, 95% CI = 1.16-1.76) experienced 30%-40% higher pooled all-cancer risk than normoxemic patients, after multiple adjustment for covariates including obesity. Furthermore, severe nocturnal hypoxemia nearly tripled all-cancer mortality (HR = 2.66, 95% CI = 1.21-5.85). Patients with apnea-hypopnea index-defined severe OSA, but not moderate OSA, had higher all-cancer risk (HR = 1.18, 95% CI = 1.03-1.35) but similar all-cancer mortality as patients without OSA. An OSA diagnosis was not associated with all-cancer risk. Evidence quality ranged from low to moderate. Insufficient evidence was available on the oxygen desaturation index, lowest/median saturation, and arousal index.

CONCLUSIONS

In patients with OSA, nocturnal hypoxemia is independently associated with all-cancer risk and mortality. Future studies should explore if risk differs by cancer type, and whether cancer screening and OSA treatment are beneficial.

SYSTEMATIC REVIEW REGISTRATION

Registry: PROSPERO; URL: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=220836; Identifier: CRD42021220836.

CITATION

Tan BKJ, Teo YH, Tan NKW, et al. Association of obstructive sleep apnea and nocturnal hypoxemia with all-cancer incidence and mortality: a systematic review and meta-analysis. J Clin Sleep Med. 2022;18(5):1427-1440.

Cancer and obstructive sleep apnea: An updated meta-analysis

OBJECTIVE

The relationship between cancers and obstructive sleep apnea (OSA) has been discussed for decades. However, the previous meta-analysis led to opposite conclusions. To further investigate this controversial issue, we performed this systematic review and meta-analysis update.

METHODS

PubMed, Embase, and the Cochrane Library were systematically searched and studies on "cancer and OSA" were all included. Two reviewers independently searched articles, extracted data, and assessed the quality of included studies. Moreover, the overall incidence of cancer and OSA in corresponding populations was calculated.

RESULTS

Of the 1434 titles identified, 22 articles involving more than 32.1 million patients were included in this meta-analysis. An overall incidence of OSA positive individuals in cancer was 46 (95%CI, 27-67)%, and the prevalence of cancers in OSA patients reached 1.53 (95%CI, 1.01-2.31) times higher than non-OSA individuals.

CONCLUSION

This meta-analysis indicated that there was a high prevalence of OSA in cancer patients, and individuals with OSA were more likely to develop tumors, and the incidence was related to the severity of OSA.

Surgical treatments for obstructive sleep apnea decrease the risk of erectile dysfunction: A nationwide cohort study

BACKGROUND

It has been reported that the risk of erectile dysfunction (ED) is significantly higher in patients with obstructive sleep apnea (OSA), compared with patients without OSA. However, there is limited evidence on whether surgical treatments in patients with OSA could decrease ED risk.

OBJECTIVES

To assess the impact of surgical treatments for OSA on the risk of ED by analysis of claims data from the Taiwan National Health Insurance Research Database between 1997 and 2012.

MATERIAL AND METHODS

We identified 20,675 male adults with newly diagnosed OSA during the study period; 16,040 patients ever received surgical treatments (treated cohort) and 4635 patients never received surgical treatments (untreated cohort). According to 3:1 propensity score matching, we analyzed 8337 patients in the treated cohort and 2779 controls in the untreated cohort. We estimated the incidence rates (IRs) and hazard ratios (HRs) of incident ED in both cohorts through the end of 2012.

RESULTS

In a total study follow-up of 64,916 person-years, 396 (3.6%) patients developed impotence. The IRs of ED for the treated and untreated cohorts, respectively, were 55.8 (95% confidence interval [CI], 55.6-55.9) and 76.1 (95% CI, 76.0-76.3) per 1000 person-years. Multivariate Cox proportional hazard analysis showed that surgical treatments for OSA patients were associated with a lower risk for ED (adjusted HR, 0.79; 95% CI, 0.64-0.98). Multivariate stratified analysis further verified that significant risk reduction of ED was present in OSA patients without hypertension, diabetes, hyperlipidemia, hyperuricemia, obesity, chronic kidney disease, and chronic liver disease.

CONCLUSIONS

We found that OSA patients who received surgical treatments were associated with a lower risk for developing ED by 21%.

Obstructive sleep apnea and incidence of malignant tumors: a meta-analysis

OBJECTIVES

This paper assessed the connection between obstructive sleep apnea (OSA) and the incidence of malignant tumors.

METHODS

PubMed, Cochrane, Scopus, Health Source Nursing Academic Edition, EMBASE, and Web of Sciences were searched until the date of July 25, 2020. The analysis included an assessment of the overall incidence of OSA malignancies, the incidence of OSA malignancies by age and gender, and the incidence of different types of malignancies in patients with OSA. The total rate and the corresponding 95% confidence interval (CI) of the incidence of malignant tumors in patients with OSA were calculated. Patients with OSA were classified according to age, gender, and different types of malignant tumors for meta-analysis.

RESULTS

A total of 12 studies involving 862,820 participants were included in this meta-analysis. Random effect model analysis showed that the total incidence of malignant tumors in patients with OSA was 0.046% (95% CI: 0.027-0.065, P < 0.001), higher than that of malignant tumors in the general population. According to the analytical results classified by gender, the incidence of malignant tumor in female patients with OSA was 4.0% (95% CI: 0.014-0.066), higher than that in male patients at 3.5% (95% CI: 0.012-0.058). The analytical results classified by age showed that the incidence of malignant tumors in patients with OSA aged below 60 years was 1.8% (95% CI: 0.000-0.036), lower than that in patients aged above 60 years at 4.3% (95% CI: 0.002-0.084). The analytical results classified by the types of malignant tumors showed that the incidences of breast cancer, lung cancer, colorectal cancer, prostate cancer, kidney cancer, pancreatic cancer, and melanoma in patients with OSA were 0.5% (95% CI: 0.001-0.008), 0.5% (95% CI: 0.002-0.009), 0.5% (95% CI: 0.003-0.008), 1.1% (95% CI: 0.002-0.021), 0.3% (95% CI: 0.001-0.005), 0.1% (95% CI: 0.001-0.002), and 0.4% (95% CI: 0.003-0.005), respectively. Among them, the incidence of prostate cancer was the highest, followed by breast cancer, lung cancer, colorectal cancer, melanoma, and kidney cancer, whereas the incidence of pancreatic cancer was the lowest. However, the incidence of specific malignant tumors in patients with OSA did not have a significant increase compared with that in the general population.

CONCLUSIONS

The analytical results of this meta-analysis suggested that OSA may be associated with an overall increase in the incidence of malignancies based on the currently available data, but the connection with specific types of malignancies was not significant. Further studies are needed to explore this association in the future.

Associations of self-reported obstructive sleep apnea with total and site-specific cancer risk in older women: a prospective study

BACKGROUND AND OBJECTIVES

Chronic intermittent hypoxia resulting from obstructive sleep apnea (OSA) may activate multiple carcinogenic pathways and lead to cancer development.

METHODS

We prospectively examined the association between OSA and cancer risk among 65,330 women in the Nurses' Health Study who were free of cancer in 2008 (mean age: 73.3 years). Incident cancer diagnoses were collected until 2016 and confirmed by pathology reports. Clinically diagnosed OSA was self-reported in 2008 and updated in 2012. We used time-dependent Cox regression to estimate hazard ratios (HR) for the associations of OSA with total and site-specific cancer risk.

RESULTS

We documented 5,257 incident cancer diagnoses during follow-up. In the age-adjusted model, OSA was associated with a 15% (95% CI: 1.03, 1.29) increase in total cancer risk. The association became nonsignificant after adjustment for multiple cancer risk factors (HR: 1.08; 95% CI: 0.96, 1.21). When examining cancer risk by site, OSA was associated with significantly increased risk for lung (fully adjusted HR: 1.52; 95% CI: 1.07, 2.17), bladder (fully adjusted HR: 1.94; 95% CI: 1.12, 3.35), and thyroid cancer (fully adjusted HR: 2.06; 95% CI: 1.01, 4.22) and possibly increased risk for kidney cancer (fully adjusted HR: 1.59; 95% CI: 0.84, 3.01). When grouping cancer sites by risk factor profiles, OSA was positively associated with smoking-related cancers (fully adjusted HR: 1.37; 95% CI: 1.11, 1.67), and this association was stronger in never smokers than ever smokers.

CONCLUSION

While OSA was not independently associated with overall cancer risk in older women, significant associations were observed for smoking-related cancers, especially in nonsmokers.

Obstructive Sleep Apnea and Incident Cancer: A Large Retrospective Multicenter Clinical Cohort Study

BACKGROUND

To examine the association between the severity of obstructive sleep apnea (OSA) and nocturnal hypoxemia with incident cancer.

METHODS

This was a multicenter retrospective clinical cohort study using linked clinical and provincial health administrative data on consecutive adults who underwent a diagnostic sleep study between 1994 and 2017 in four academic hospitals (Canada) who were free of cancer at baseline. Cancer status was derived from the Ontario Cancer Registry. Cox cause-specific regressions were utilized to address the objective and to calculate the 10-year absolute risk difference (ARD) in the marginal probability of incident cancer and the number needed to harm (NNH).

RESULTS

Of 33,997 individuals considered, 33,711 with no missing OSA severity were included: median age, 50 years; 58% male; and 23% with severe OSA (apnea-hypopnea index >30). Of the 18,458 individuals with information on sleep time spent with oxygen saturation (SaO₂) <90%, 5% spent >30% of sleep with SaO₂ <90% (severe nocturnal hypoxemia). Over a median of 7 years, 2,498 of 33,711 (7%) individuals developed cancer, with an incidence rate of 10.3 (10.0-10.8) per 1,000 person-years. Controlling for confounders, severe OSA was associated with a 15% increased hazard of developing cancer compared with no OSA (HR = 1.15, 1.02-1.30; ARD = 1.28%, 0.20-2.37; and NNH = 78). Severe hypoxemia was associated with about 30% increased hazard (HR = 1.32, 1.08-1.61; ARD = 2.38%, 0.47-4.31; and NNH = 42).

CONCLUSIONS

In a large cohort of individuals with suspected OSA free of cancer at baseline, the severity of OSA and nocturnal hypoxemia was independently associated with incident cancer.

IMPACT

These findings suggest the need for more targeted cancer risk awareness in individuals with OSA.

Obstructive sleep apnea in children with hypothalamic obesity: Evaluation of possible related factors

INTRODUCTION

Hypothalamic obesity (HO) is a type of obesity that is caused by hypothalamic damage. HO can be complicated by obstructive sleep apnea syndrome (OSAS) due to anatomical narrowing of the upper airway and hypothalamic damage-induced dysfunction of the sleep control mechanisms. We aimed to explore the presence and severity of OSAS in children with HO and hypothesized that OSAS is more severe and frequent in HO than exogenous obesity (EO).

METHODS

This cross-sectional study was conducted among children aged 6.6-17.9 years. Subjects with HO (n = 14) and controls with EO (n = 19) were consecutively recruited through an endocrinology clinic. All patients underwent full-night polysomnography. The primary outcomes were obstructive apnea-hypopnea index (OAHI) and the severity of OSAS. We analyzed the polysomnography findings, biochemical parameters, Brodsky and modified Mallampati scores, and blood pressure compared with the controls. We explored the different obesity types and these variables in association with OAHI using multiple linear regression (MLR).

RESULTS

Age and body mass index z scores (BMI-z) were similar between the EO and HO groups. The OAHI of HO (5.8) was higher than that of EO (2.2). In MLR, the predicted OAHI was formulated as an equation using regression coefficients of obesity type (HO), age, and BMI-z (R²  = .41). In the logistic regression analysis, the odds ratio of moderate/severe OSA was 5.6 for HO.

CONCLUSIONS

Children with HO have a higher risk of moderate/severe OSAS than children with EO. Polysomnography should be considered in all patients with HO.

Sleep disorders and cancer: State of the art and future perspectives

A bidirectional connection between sleep and cancer exists; however, the specific associations between individual sleep disorders and particular tumors are not very clear. An accurate assessment of sleep disorders in cancer patients is necessary to improve patient health, survival, response to therapy, quality of life, reduction of comorbidities/complications. Indeed, recent scientific evidence shows that knowledge and management of sleep disorders offer interesting therapeutic perspectives for the treatment of cancer. In light of this need, the objective of this review is to assess the evidence highlighted in the research of the last ten years on the correlation between each specific category of sleep disorder according to the International Classification of Sleep Disorders 3rd Ed. and several types of tumor based on their anatomical location (head-neck, including the brain and thyroid; lung; breast; ovary; endometrium; testes; prostate; bladder; kidney; gastrointestinal tract, subdivided into: stomach, liver, colon, pancreas; skin; bone tumors; hematological malignancies: leukemia, lymphoma, multiple myeloma, polycythemia), in order to evaluate what is currently known about: 1) sleep disorders as cancer risk factor; 2) tumors associated with the onset of sleep disorders; 3) targeted therapies of sleep disorders in cancer patients and new oncological perspectives following the evaluation of sleep.

Sleep Apnoea Adverse Effects on Cancer: True, False, or Too Many Confounders?

Obstructive sleep apnoea (OSA) is a prevalent disorder associated with increased cardiovascular, metabolic and neurocognitive morbidity. Recently, an increasing number of basic, clinical and epidemiological reports have suggested that OSA may also increase the risk of cancer, and adversely impact cancer progression and outcomes. This hypothesis is convincingly supported by biological evidence linking certain solid tumours and hypoxia, as well as by experimental studies involving cell and animal models testing the effects of intermittent hypoxia and sleep fragmentation that characterize OSA. However, the clinical and epidemiological studies do not conclusively confirm that OSA adversely affects cancer, even if they hold true for specific cancers such as melanoma. It is likely that the inconclusive studies reflect that they were not specifically designed to test the hypothesis or because of the heterogeneity of the relationship of OSA with different cancer types or even sub-types. This review critically focusses on the extant basic, clinical, and epidemiological evidence while formulating proposed directions on how the field may move forward.

The incidence of malignant brain tumors is increased in patients with obstructive sleep apnea: A national health insurance survey

The association between obstructive sleep apnea (OSA) and malignant brain tumors has yet to be fully investigated. Therefore, the purpose of this study was to elucidate the effect of OSA on brain tumor incidence based on the Korea National Health Insurance Service (KNHIS) dataset. The KNHIS data between 2007 and 2014 were analyzed, and the primary endpoint was newly diagnosed malignant brain tumor. A total of 198,574 subjects aged ≥ 20 years with newly diagnosed OSA were enrolled in the study, and 992,870 individuals were selected as a control group based on propensity score matching (PSM) by gender and age. The average follow-up duration was 4.8 ± 2.3 years. The hazard ratios (HRs) for brain tumor for patients with OSA were 1.78 (95% confidence interval [CI]: 1.42-2.21) in Model 1 (not adjusted with any covariate) and 1.67 (95% CI: 1.34-2.09) in Model 2 (adjusted for income level, diabetes, hypertension, dyslipidemia, and COPD). In subgroup analysis by gender, the odds ratios (OR) of OSA were 1.82 (95% CI: 1.41-2.33) in men and 1.26 (95% CI: 0.74-2.03) in women. The ORs were 1.97 (95% CI: 1.15-3.24) in the older (age ≥ 65 years) group, 1.66 (95% CI: 1.25-2.17) in the middle-aged (40 ≤ age < 65 years) group, and 1.41 (0.78-2.44) in the young (20 ≤ age < 40 years) group. In conclusion, OSA may increase the incidence of brain tumors.

Role of the Cyclooxygenase Pathway in the Association of Obstructive Sleep Apnea and Cancer

The objective of this review is to examine the findings that link obstructive sleep apnea (OSA) with cancer and the role played by the cyclooxygenase (COX) pathway in this association. Epidemiological studies in humans suggest a link between OSA and increased cancer incidence and mortality. Studies carried out in animal models have shown that intermittent hypoxia (IH) induces changes in several signaling pathways involved in the regulation of host immunological surveillance that results in tumor establishment and invasion. IH induces the expression of cyclooxygenase 2 (COX-2) that results in an increased synthesis of prostaglandin E2 (PGE₂). PGE₂ modulates the function of multiple cells involved in immune responses including T lymphocytes, NK cells, dendritic cells, macrophages, and myeloid-derived suppressor cells. In a mouse model blockage of COX-2/PGE₂ abrogated the pro-oncogenic effects of IH. Despite the fact that aspirin inhibits PGE₂ production and prevents the development of cancer, none of the epidemiological studies that investigated the association of OSA and cancer included aspirin use in the analysis. Studies are needed to investigate the regulation of the COX-2/PGE₂ pathway and PGE₂ production in patients with OSA, to better define the role of this axis in the physiopathology of OSA and the potential role of aspirin in preventing the development of cancer.

Obstructive sleep apnea and cancer: a complex relationship

PURPOSE OF REVIEW

Obstructive sleep apnea (OSA) has been recognized as a risk factor for cancer mainly through hypoxia, based on studies that did not distinguish among cancer types. The purpose of this review is to discuss the most recent data on epidemiology and pathophysiology of the OSA-cancer association.

RECENT FINDINGS

According to epidemiological studies, OSA may have different influences on each type of cancer, either increasing or decreasing its incidence and aggressiveness. Time spent with oxygen saturation below 90% appears the polysomnographic variable most strongly associated with unfavorable effects on cancer. Experimental studies support the role of hypoxia as an important risk factor for cancer growth and aggressiveness, especially when it shows an intermittent pattern. These effects are largely mediated by the hypoxia-inducible factor, which controls the synthesis of molecules with effects on inflammation, immune surveillance and cell proliferation. Sleep fragmentation participates in increasing cancer risk. Modulating effects of age remain controversial.

SUMMARY

Effects of OSA on cancer may largely vary among neoplastic diseases, both in their magnitude and direction. The worse risk associated with intermittent rather than persistent hypoxia, and the effects of OSA therapy on cancer natural history are still poorly known, and deserve new careful studies.

The incidence of non-Hodgkin lymphoma is increased in patients with obstructive sleep apnea

Obstructive sleep apnea (OSA) is known to be associated with several cancers, but studies assessing the association between OSA and lymphoma have not been conducted yet. This study aimed to investigate the associations between OSA and non-Hodgkin lymphoma, which accounts for the majority of lymphoma, using the Korea National Health Insurance Service database. This retrospective cohort study analyzed the data from the Korea National Health Insurance Service database. A total of 198,574 patients aged ≥ 20 years who were newly diagnosed with OSA between 2007 and 2014 were included. The control group comprising 992,870 subjects was selected using propensity score matching by age and sex. The mean follow-up duration was 4.8 ± 2.3 years. The primary endpoint was newly diagnosed non-Hodgkin lymphoma. The hazard ratio [95 % confidence interval] of OSA for the incidence of non-Hodgkin lymphoma was calculated based on Cox proportional hazard model. The incidence of non-Hodgkin lymphoma among patients with OSA was significantly higher than that among the controls (1.40 [1.16-1.69]). In particular, the incidence was higher in women than that in men (1.62 vs. 1.28). There was no difference in hazard ratio by age. In conclusion, OSA may be a risk factor for non-Hodgkin lymphoma.

The Association of Sleep Disorders, Obesity and Sleep-Related Hypoxia with Cancer

BACKGROUND

Sleep disorders have emerged as potential cancer risk factors.

OBJECTIVE

This review discusses the relationships between sleep, obesity, and breathing disorders with concomitant risks of developing cancer.

RESULTS

Sleep disorders result in abnormal expression of clock genes, decreased immunity, and melatonin release disruption. Therefore, these disorders may contribute to cancer development. Moreover, in sleep breathing disorder, which is frequently experienced by obese persons, the sufferer experiences intermittent hypoxia that may stimulate cancer cell proliferation.

DISCUSSION

During short- or long- duration sleep, sleep-wake rhythm disruption may occur. Insomnia and obstructive sleep apnea increase cancer risks. In short sleepers, an increased risk of stomach cancer, esophageal squamous cell cancer, and breast cancer was observed. Among long sleepers (>9 hours), the risk of some hematologic malignancies is elevated.

CONCLUSION

Several factors including insomnia, circadian disruption, obesity, and intermittent hypoxia in obstructive sleep apnea are contributing risk factors for increased risk of several types of cancers. However, further studies are needed to determine the more significant of these risk factors and their interactions.

Five-year relative survival in sleep apnea patients with a subsequent cancer diagnosis

STUDY OBJECTIVES

In vitro and animal studies suggest that intermittent hypoxia characterizing sleep apnea contributes to accelerated cancer progression. However, the impact of sleep apnea on survival subsequent to cancer diagnosis is unknown.

METHODS

We identified a cohort of 1,575 adults diagnosed with sleep apnea between 2005 and 2014 with a subsequent cancer diagnosis via linkage of the University of Washington Medicine system and a population-based cancer registry serving the same Seattle-Puget Sound region. We computed age-standardized 5-year relative survival after cancer diagnosis for all cancers combined, and for specific cancer sites, for both the sleep apnea cohort and the general Seattle-Puget Sound population, and we used US life tables as the reference population. Relative survival was estimated by sex, cancer stage, and health care engagement.

RESULTS

Five-year overall relative survival for cancer was more favorable in the sleep apnea cohort than in the general population [83.6%, 95% confidence interval (CI): 79.8%-86.8% vs 71.6%, 95% CI: 71.3%-71.9%]; this pattern was applicable to most specific cancer sites. However, 5-year relative survival was slightly less favorable in the sleep apnea cohort among patients with melanoma (97.7%, 95% CI: 84.6%-99.7% vs 99.2%, 95% CI: 98.8%-99.5%) and cancer of the corpus uteri (84.0%, 95% CI: 58.2%-94.5% vs 84.6%, 95% CI: 83.1%-86.0%).

CONCLUSIONS

The fact that survival after cancer, overall and for most cancer sites, was more favorable in patients with sleep apnea warrants larger community-based studies to further tease out effects of sleep apnea and treatment on site-specific survival for different cancer types, particularly in patients with melanoma or uterine cancer.

The Association of Sleep Apnea and Cancer in Veterans

Objective

To test the association between preexisting obstructive sleep apnea (OSA) and subsequent cancer in a large long-term cohort of veteran patients.

Study Design

Retrospective matched cohort study.

Setting

The Veterans Affairs Health Care System.

Subjects and Methods

All veteran patients diagnosed with OSA between 1993 and 2013 by International Classification of Diseases, Ninth Revision ( ICD-9) codes in any Veterans Affairs facility and veteran patients without an OSA diagnosis, matched to patients with OSA by age and index year. Cancer diagnoses were identified by ICD-9 codes for the time period at least 2 years after OSA diagnosis or index date. We tested the association between OSA and cancer using multivariate Cox regression with time since cohort entry as the time axis, adjusting for potential confounders.

Results

The cohort included 1,377,285 patients (726,008 with and 651,277 without an OSA diagnosis) with mean age of 55 years, predominantly male (94%), a minority obese (32%), and median follow-up of 7.4 years (range, 2.0-25.2). The proportion of patients diagnosed with cancer was higher in those with vs without an OSA diagnosis (8.3% vs 3.6%; mean difference 4.8%; 95% confidence interval [CI], 4.7%-4.8%; P < .001). After adjusting for age, sex, year of cohort entry, smoking status, alcohol use, obesity, and comorbidity, the hazard of incident cancer was nearly double in patients with vs without an OSA diagnosis (hazard ratio, 1.97; 95% CI, 1.94-2.00; P < .001).

Conclusion

Preexisting OSA was strongly associated with subsequent cancer in this veteran cohort, independent of several known cancer risk factors. These findings suggest that OSA may be a strong, independent risk factor for subsequent cancer development.

Telomere Length and Risk of Major Adverse Cardiac Events and Cancer in Obstructive Sleep Apnea Patients

Telomere length (TL) is associated with cardiovascular disease (CVD) and cancer. Obstructive sleep apnea (OSA) is also linked to higher risk of CVD and cancer, and to TL. We investigated the association between TL and risk of major adverse cardiac events (MACE) and cancer in OSA patients. We studied 210 individuals undergoing sleep-related studies between 2000 and 2007. Baseline characteristics and follow-up data (available in 164 subjects) were obtained from clinic records. Incidence rates were calculated for the entire group and by OSA status. Hazard ratios were calculated to estimate effects of OSA and TL on risk of MACE and cancer. In total, 32 individuals (20%) developed MACE and/or cancer during 12.7-year follow-up. The OSA group had a higher likelihood of cancer (16.0 vs. 4.9 events per 1000 person-years, P = 0.044) but no clear evidence of an elevated incidence of MACE (10.8 vs. 4.8 events per 1000 person-years, P = 0.293) compared to the non-OSA group. There was no association between TL and MACE- (HR = 1.01, 95% CI 0.78–1.28), or cancer-risk (HR = 1.18, 95% CI 0.96–1.43). Our study warrants further investigation of any modulating effect of OSA on TL and the risk of MACE and cancer.

Obstructive sleep apnea and comorbidities: a dangerous liaison

Obstructive sleep apnea (OSA) is a highly prevalent disease, and is traditionally associated with increased cardiovascular risk. The role of comorbidities in OSA patients has emerged recently, and new conditions significantly associated with OSA are increasingly reported. A high comorbidity burden worsens prognosis, but some data suggest that CPAP might be protective especially in patients with comorbidities. Aim of this narrative review is to provide an update on recent studies, with special attention to cardiovascular and cerebrovascular comorbidities, the metabolic syndrome and type 2 diabetes, asthma, COPD and cancer. Better phenotypic characterization of OSA patients, including comorbidities, will help to provide better individualized care. The unsatisfactory adherence to CPAP in patients without daytime sleepiness should prompt clinicians to examine the overall risk profile of each patient in order to identify subjects at high risk for worse prognosis and provide the optimal treatment not only for OSA, but also for comorbidities.

Holistic Management of Obstructive Sleep Apnea: Translating Academic Research to Patient Care

A holistic approach is pertinent in managing obstructive sleep apnea (OSA). It goes beyond integrated multidisciplinary assessment and management in the hospital setting. Although clinicians should be aware of different treatment modalities and adjunctive measures, proactive management of OSA is as important. The future of OSA management lies in identifying patients at risk of developing OSA and developing strategy to prevent OSA from taking root. It involves active screening of patients with OSA and treating them and identifying patients with OSA with high risk of preventable serious morbidity and death and intervening early to prevent these from happening.

Anti-tumor effect of endostatin in a sleep-apnea mouse model with tumor

BACKGROUND

Obstructive sleep apnea (OSA) is associated with cancer incidence and mortality. The underlying mechanism is unclear. This study aims to evaluate the influence of intermittent hypoxia (IH), a novel hallmark of OSA, on tumor and to access the anti-tumor effect of endostatin on a mouse model with OSA.

METHODS

The C57BL/6 J mice were randomly classified into four groups: control (normoxia) (CTL), control plus endostatin (CTL + ED), IH, and IH plus endostatin (IH + ED). Mice in IH and IH + ED groups were subjected to IH 8 h per day in 5 weeks. Lewis lung cancer cells were injected into the flank of each mouse after 1 week of IH exposure. Endostatin was also intraperitoneally injected after tumor volume reached about 200 mm³. The maximum standard uptake values (SUVmax) were detected by micro-positron emission tomography-computed tomography (micro-PET-CT) imaging prior and post-endostatin administration. Microvessel density (MVD) and vascular endothelial growth factor (VEGF) were determined for evaluating the anti-tumor effect of endostatin among the normoxia and IH conditions.

RESULTS

Mice had higher SUVmax in the IH group than the CTL group (p < 0.01). When compared with mice in the CTL group, those in the IH group had significantly greater MVD values (p < 0.001). The SUVmax can be attenuated by endostatin both in the CTL (p < 0.01) and IH conditions (p < 0.001). When compared with CTL group, mice in the IH group had increased MVD values (p < 0.001) and VEGF expression both at mRNA (p < 0.05) and protein levels (p < 0.001 in western blotting results). Treatment with endostatin attenuated serum and tissue VEGF levels, lowering the MVD values. As compared to normoxia condition, the endostatin-therapeutic effects were more significant under the IH condition (p < 0.05 in western blotting results).

CONCLUSIONS

Micro-PET-CT imaging is a promising non-invasive technique to evaluate the tumor metabolic characteristics under IH condition in vivo. The anti-tumor effect of endostatin under IH condition is superior to that of the normoxia condition.

Sleep apnea and subsequent cancer incidence

PURPOSE

In vitro and animal models suggest that the physiological effects of sleep apnea could contribute to cancer risk, yet epidemiologic studies have been inconsistent.

METHODS

We identified a cohort of adults diagnosed with sleep apnea between 2005 and 2014 using regional administrative databases. Linking this cohort to a population-based cancer registry, we identified first incident cancers diagnosed after sleep apnea diagnosis through 2015. We calculated age-sex standardized cancer incidence ratios (SIRs) to compare the observed number of cancers among those with sleep apnea with expected population estimates over a comparable period.

RESULTS

Among 34,402 individuals with sleep apnea, 1,575 first incident cancers were diagnosed during follow-up (mean ± SD; 5.3 ± 2.0 years). Compared to the general population, cancer incidence (SIR 1.26, 95% CI 1.20-1.32) was elevated among sleep apnea patients. We observed significantly elevated incidence for kidney (SIR 2.24, 95% CI 1.82-2.72), melanoma (SIR 1.71, 95% CI 1.42-2.03), breast (SIR 1.43, 95% CI 1.76-2.00), and corpus uteri (SIR 2.80, 95% CI 2.24-2.47) while risk for lung (SIR 0.66, 95% CI 0.54-0.79) and colorectal cancer (SIR 0.71, 95% CI 0.56-0.89) was lower.

CONCLUSION

These findings suggest an elevated cancer burden, particularly at certain sites, among individuals with diagnosed sleep apnea. Results should be interpreted with caution due to unmeasured confounders (e.g., BMI, diabetes).

Models of intermittent hypoxia and obstructive sleep apnea: molecular pathways and their contribution to cancer

Obstructive sleep apnea (OSA) is common and linked to a variety of poor health outcomes. A key modulator of this disease is nocturnal intermittent hypoxia. There is striking epidemiological evidence that patients with OSA have higher rates of cancer and cancer mortality. Small-animal models demonstrate an important role for systemic intermittent hypoxia in tumor growth and metastasis, yet the underlying mechanisms are poorly understood. Emerging data indicate that intermittent hypoxia activates the hypoxic response and inflammatory pathways in a manner distinct from chronic hypoxia. However, there is significant heterogeneity in published methods for modeling hypoxic conditions, which are often lacking in physiological relevance. This is particularly important for studying key transcriptional mediators of the hypoxic and inflammatory responses such as hypoxia-inducible factor (HIF) and NF-κB. The relationship between HIF, the molecular clock, and circadian rhythm may also contribute to cancer risk in OSA. Building accurate in vitro models of intermittent hypoxia reflective of OSA is challenging but necessary to better elucidate underlying molecular pathways.

Application of Personalized, Predictive, Preventative, and Participatory (P4) Medicine to Obstructive Sleep Apnea. A Roadmap for Improving Care?

Dr. Leroy Hood promotes a paradigm to advance medical care that he calls P4 medicine. The four Ps are: personalized, predictive, preventative, and participatory. P4 medicine encourages a convergence of systems medicine, the digital revolution, and consumer-driven healthcare. Might P4 medicine be applicable to obstructive sleep apnea (OSA)? OSA should be personalized in that there are different structural and physiological pathways to disease. Obesity is a major risk factor. The link between obesity and OSA is likely to be fat deposits in the tongue compromising the upper airway. Clinical features at presentation also vary between patients. There are three distinct subgroups: (1) patients with a primary complaint of insomnia, (2) relatively asymptomatic patients with a high prevalence of cardiovascular comorbidities, and (3) excessively sleepy patients. Currently, there have been limited efforts to identify subgroups of patients on the basis of measures obtained by polysomnography. Yet, these diagnostic studies likely contain considerable predictive information. Likewise, there has currently been limited application of -omic approaches. Determining the relative role of obesity and OSA for particular consequences is challenging, because they both affect the same molecular pathways. There is evidence that the effects of OSA are modified by the level of obesity. These insights may lead to improvements in predicting outcomes to personalized therapies. The final P-participatory-is ideally suited to OSA, with technology to obtain extensive data remotely from continuous positive airway pressure machines. Providing adherence data directly to patients increases their use of continuous positive airway pressure. Thus, the concept of P4 medicine is very applicable to obstructive sleep apnea and can be the basis for future research efforts.

Tinnitus Is Associated with a Higher Risk of Benign Brain Tumors: A Nationwide, Population-Based Secondary Cohort Study of Young and Middle-Aged Adults

BACKGROUND

It remains unclear whether tinnitus is associated with a higher risk of benign or malignant brain tumors in humans. Therefore, the aim of this secondary study was to investigate the risk of brain tumors in adult with tinnitus using data from a nationwide health claims research database.

METHODS

Patients aged 20-50 years who were newly diagnosed with tinnitus were identified from the Taiwan's National Health Insurance Research Database and they served as the study cohort. A comparison cohort was formed by using patients without tinnitus from the same database with frequency matching (4: 1) by 10-year age interval and gender to the patients in the tinnitus cohort. Cox proportional hazards models were used to calculate the adjusted hazard ratios (AHR) for benign and malignant brain tumors in patients with tinnitus, adjusting for age, gender, and comorbidities.

RESULTS

There were 15,819 patients in the tinnitus cohort and 63,276 in the comparison cohort. A significantly higher proportion of patients with tinnitus had benign brain tumor (p = 0.003) and all 11 comorbid conditions (p < 0.001) compared to those without tinnitus. Cox proportional hazards regression analysis performed on the basis of age, gender, and the 11 comorbidities revealed that tinnitus was independently associated with a higher risk for benign brain tumor (AHR 1.65, 95% CI 1.24-2.20, p = 0.001) and but not with malignant brain tumors (AHR 1.66, 95% CI 0.93-2.94, p = 0.085).

CONCLUSIONS

Findings from this secondary cohort analysis indicated that tinnitus is associated with a higher risk of benign brain tumors.

Role of Cyclooxygenase-2 on Intermittent Hypoxia-Induced Lung Tumor Malignancy in a Mouse Model of Sleep Apnea

An adverse role for obstructive sleep apnea (OSA) in cancer epidemiology and outcomes has recently emerged from clinical and animal studies. In animals, intermittent hypoxia (IH) mimicking OSA promotes tumor malignancy both directly and via host immune alterations. We hypothesized that IH could potentiate cancer aggressiveness through activation of the cyclooxygenase-2 (COX-2) pathway and the concomitant increases in prostaglandin E2 (PGE₂). The contribution of the COX-2 in IH-induced enhanced tumor malignancy was assessed using celecoxib as a COX-2 specific inhibitor in a murine model of OSA bearing Lewis lung carcinoma (LLC1) tumors. Exposures to IH accelerated tumor progression with a tumor associated macrophages (TAMs) shift towards a pro-tumoral M2 phenotype. Treatment with celecoxib prevented IH-induced adverse tumor outcomes by inhibiting IH-induced M2 polarization of TAMs. Furthermore, TAMs isolated from IH-exposed mice treated with celecoxib reduced the proliferation of LLC1 naïve cells, while the opposite occurred with placebo-treated IH-exposed mice. Finally, in vitro IH exposures of murine macrophages and LLC1 cells showed that both cell types increased PGE₂ release in response to IH. These results suggest a crucial role for the COX-2 signaling pathway in the IH-exacerbated malignant processes, and designate macrophages and lung adenocarcinoma cells, as potential sources of PGE₂.

Sleep and Breathing … and Cancer?

Sleep, like eating and breathing, is an essential part of the daily life cycle. Although the science is still emerging, sleep plays an important role in immune, cardiovascular, and neurocognitive function. Despite its great importance, nearly 40% of U.S. adults experience problems with sleep ranging from insufficient total sleep time, trouble initiating or maintaining sleep (Insomnia), circadian rhythm disorders, sleep-related movement disorders, and sleep-related breathing disorders such as obstructive sleep apnea (OSA). Herein, we discuss new evidence that suggests that sleep may also affect carcinogenesis. Specifically, we review recent epidemiologic data suggesting links between cancer and OSA. As OSA is a common, underdiagnosed, and undertreated condition, this has public health implications. Intriguing animal model data support a link between cancer and sleep/OSA, although mechanisms are not yet clear. Leaders in the fields of sleep medicine, pulmonology, and oncology recently met to review and discuss these data, as well as to outline future directions of study. We propose a multidisciplinary, three-pronged approach to studying the associations between cancer and sleep, utilizing mutually interactive epidemiologic studies, preclinical models, and early-phase clinical trials. Cancer Prev Res; 9(11); 821-7. ©2016 AACR.

Risk of tinnitus in patients with sleep apnea: A nationwide, population-based, case-control study

OBJECTIVE

To investigate the risk of tinnitus in patients with sleep disturbance or sleep apnea.

STUDY DESIGN

Case control study.

METHODS

We identified 21,798 middle-aged and elderly patients with otolaryngologist-diagnosed tinnitus between January 1, 2000, and December 31, 2012, from the Longitudinal Health Insurance Database 2000 of the Taiwan National Health Insurance Research Database. A total of 108,990 controls were also identified from the same database based on frequency-matching on 10-year age interval, sex, and year of index date of the cases. Diagnoses of sleep disturbance (International Classification of Diseases, 9th Revision, Clinical Modification [ICD-9-CM] codes 780.50, 780.52, 307.4) and sleep apnea (ICD-9-CM codes 780.51, 780.53, 780.57) in the cases and controls prior to the index date were assessed. The risks of tinnitus in patients with sleep disturbance and sleep apnea were separately evaluated with multivariate logistic regression analyses.

RESULTS

The mean age of the total 130,788 patients was 59.8 years, and 47% of them were males. The risk of tinnitus was higher in patients with sleep disturbance compared to those without the condition (adjusted odds ratio [OR] = 1.13, 95% confidence interval [CI] [95% CI] = 1.11-1.17), and the risk of tinnitus was higher in patients with sleep apnea compared to those without the condition (adjusted OR = 1.36, 95% CI = 1.16-1.60).

CONCLUSION

In this population-based, case-control study, the risk of tinnitus was found to be significantly higher among middle-aged and elderly Taiwanese patients with sleep disturbances, especially with sleep apnea.

LEVEL OF EVIDENCE

3b. Laryngoscope, 127:2171-2175, 2017.

Emerging co-morbidities of obstructive sleep apnea: cognition, kidney disease, and cancer

Obstructive sleep apnea (OSA) causes daytime fatigue and sleepiness, and has an established relationship with cardiovascular and metabolic disease. Recent years have seen the emergence of an evidence base linking OSA with an increased risk of degenerative neurological disease and associated cognitive impairment, an accelerated rate of decline in kidney function with an increased risk of clinically significant chronic kidney disease (CKD), and with a significantly higher rate of cancer incidence and death. This review evaluates the evidence base linking OSA with these seemingly unrelated co-morbidities, and explores potential mechanistic links underpinning their development in patients with OSA, including intermittent hypoxia (IH), sleep fragmentation, sympathetic excitation, and immune dysregulation.

Tumor Cell Malignant Properties Are Enhanced by Circulating Exosomes in Sleep Apnea

BACKGROUND

OSA is associated with increased cancer incidence and mortality. Exosomes are vesicles secreted by most cells. They are released into the bloodstream and play a role in tumor progression and metastasis. We evaluated whether the chronic intermittent hypoxia (IH) that characterizes OSA leads to release of tumor-promoting exosomes in the circulation.

METHODS

C57/B6 male mice were randomized to 6 weeks of IH or room air (RA). A subgroup was injected with TC1 lung carcinoma cells in the left flank after 2 weeks of IH. Exosomes from mouse plasma and from 10 adult human patients with OSA before and after treatment for 6 weeks were cocultured with mouse TC1 and human adenocarcinoma cells lines. Malignant tumor properties such as proliferation, migration, invasion, and endothelial monolayer disruption were assessed, as was micro-RNA (miRNA), exosomal content, and transcriptomic effects of exosomes on TC1 cells in vitro to identify target genes.

RESULTS

Application of IH-induced exosomes from either IH-exposed tumor-bearing (IH+) or non-tumor-bearing (IH-) mice significantly promoted TC1 malignant properties. Similarly, before adherent treatment, exosomes from patients with OSA significantly enhanced proliferation and migration of human adenocarcinoma cells compared with after adherent treatment. Eleven distinct miRNAs emerged in IH-exposed mice, and their gene targets in TC1 cells were identified.

CONCLUSIONS

Circulating exosomes released under IH conditions in vivo selectively enhance specific properties of lung tumor cell cultures. Thus, plasma exosomes participate in the increased tumor aggressiveness observed in patients with OSA.