Relationship Between Sleep Apnea and Cancer

Long non-coding RNA FKSG29 regulates oxidative stress and endothelial dysfunction in obstructive sleep apnea

Altered expressions of pro-/anti-oxidant genes are known to regulate the pathophysiology of obstructive sleep apnea (OSA).We aim to explore the role of a novel long non-coding (lnc) RNA FKSG29 in the development of intermittent hypoxia with re-oxygenation (IHR)-induced endothelial dysfunction in OSA. Gene expression levels of key pro-/anti-oxidant genes, vasoactive genes, and the FKSG29 were measured in peripheral blood mononuclear cells from 12 subjects with primary snoring (PS) and 36 OSA patients. Human monocytic THP-1 cells and human umbilical vein endothelial cells (HUVEC) were used for gene knockout and double luciferase under IHR exposure. Gene expression levels of the FKSG29 lncRNA, NOX2, NOX5, and VEGFA genes were increased in OSA patients versus PS subjects, while SOD2 and VEGFB gene expressions were decreased. Subgroup analysis showed that gene expression of the miR-23a-3p, an endogenous competitive microRNA of the FKSG29, was decreased in sleep-disordered breathing patients with hypertension versus those without hypertension. In vitro IHR experiments showed that knock-down of the FKSG29 reversed IHR-induced ROS overt production, early apoptosis, up-regulations of the HIF1A/HIF2A/NOX2/NOX4/NOX5/VEGFA/VEGFB genes, and down-regulations of the VEGFB/SOD2 genes, while the protective effects of FKSG29 knock-down were abolished by miR-23a-3p knock-down. Dual-luciferase reporter assays confirmed that FKSG29 was a sponge of miR-23a-3p, which regulated IL6R directly. Immunofluorescence stain further demonstrated that FKSGH29 knock-down decreased IHR-induced uptake of oxidized low density lipoprotein and reversed IHR-induced IL6R/STAT3/GATA6/ICAM1/VCAM1 up-regulations. The findings indicate that the combined RNA interference may be a novel therapy for OSA-related endothelial dysfunction via regulating pro-/anti-oxidant imbalance or targeting miR-23a-IL6R-ICAM1/VCAM1 signaling.

Obstructive sleep apnea syndrome and causal relationship with female breast cancer: a mendelian randomization study

Although observational studies have reported a positive association between obstructive sleep apnea syndrome (OSAS) and breast cancer (BC) risk, causality remains inconclusive. We aim to explore whether OSAS is associated with etiology of BC by conducting a two-sample Mendelian randomization (MR) study in a Chinese population and Asian population from the Breast Cancer Association Consortium (BCAC). We found a detrimental causal effect of OSAS on BC risk in the primary analysis of our samples (IVW OR, 2.47 for BC risk per log-odds increment in OSAS risk, 95% CI = 1.86-3.27; P = 3.6×10^-10). This was very similar to results of the direct observational case-control study between OSAS and BC risk (OR = 2.80; 95% CI = 2.24-3.50; P =1.4×10^-19). Replication in the Asian population of the BCAC study also supported our results (IVW OR, 1.33 for BC risk per log-odds increment in OSAS risk, 95% CI = 1.13-1.56; P = 0.0006). Sensitivity analyses confirmed the robustness of our findings. We provide novel evidence that genetically determined higher risk of OSAS has a causal effect on higher risk of BC. Further studies focused on the mechanisms of the relationship between OSAS and breast carcinogenesis are needed.

Obstructive sleep apnoea and comorbidity - an overview of the association and impact of continuous positive airway pressure therapy

INTRODUCTION

Obstructive sleep apnoea (OSA) is highly prevalent and there is considerable evidence supporting an independent association with a wide range of co-morbidities including cardiovascular, endocrine and metabolic, neuropsychiatric, pulmonary, and renal. Areas covered: A PubMed search of all the recent literature relating to OSA and co-morbidities was undertaken to critically evaluate the potential relationships and possible benefit of continuous positive airway pressure (CPAP) therapy. Expert commentary: The evidence supporting an independent association is stronger for some co-morbidities than others and in cardiovascular diseases is strongest for hypertension and atrial fibrillation. Potential mechanisms include intermittent hypoxia, fluctuating intrathoracic pressure, and recurring micro-arousals that trigger cell and molecular consequences including sympathetic excitation, systemic inflammation and oxidative stress, in addition to metabolic and endothelial dysfunction. Different mechanisms may predominate in individual co-morbidities. Recent long term randomised controlled trials have cast doubt on benefits to co-morbidities from CPAP therapy of OSA, especially where co-morbidities are already established. However, benefits may result in patients who are compliant with therapy and further research is required to clearly establish the role of OSA therapy in both primary and secondary prevention of co-morbidities.

Obstructive sleep apnea is associated with an increased risk of colorectal neoplasia

BACKGROUND AND AIMS

A recent meta-analysis showed that obstructive sleep apnea (OSA) is associated with a higher prevalence of cancer and cancer-related mortality; however, little information is available on the association between OSA and colorectal neoplasia.

METHODS

We identified consecutive patients who underwent overnight polysomnography (PSG) and subsequent colonoscopy. We compared the prevalence of colorectal neoplasia between patients with or without OSA according to the results of PSG. For each patient with OSA, 1 or 2 controls matched for age (±5 years), sex, body mass index (BMI), and smoking who had undergone first-time screening colonoscopy were selected.

RESULTS

Of the 163 patients, 111 patients were diagnosed with OSA and 52 patients were within the normal range of the Apnea-Hypopnea Index. Of the 111 patients with OSA, 18 patients (16.2%) had advanced colorectal neoplasia, including 4 (3.6%) colorectal cancers. In the multivariate analyses, OSA was associated with an increased risk of advanced colorectal neoplasia after adjusting for factors including age and sex (mild: odds ratio [OR], 14.09; 95% confidence interval [CI], 1.55-127.83; P = .019; moderate or severe: OR, 14.12; 95% CI, 1.52-131.25; P = .020). Our case-control study revealed that the odds of detecting advanced colorectal neoplasia among patients with OSA were approximately 3.03 times greater than in the controls matched for age, sex, BMI, and smoking (OR, 3.03; 95% CI, 1.44-6.34; P = .002).

CONCLUSION

Physicians should be aware of the association between OSA and the development of colorectal neoplasia and explain the need for colonoscopy to patients with OSA.

Obstructive sleep apnea and dermatologic disorders

Obstructive sleep apnea (OSA) is present in at least 2% of women and 4% of men, and its prevalence is increasing, because a major predisposing factor for OSA is a high body mass index. Psoriasis has the most strongly substantiated link with OSA, where the relationship may be bidirectional. Dermatologic disorders may be comorbid with OSA due to several factors: (i) the heightened proinflammatory state in OSA, which can occur independent of body mass index, and may exacerbate inflammatory dermatoses; (ii) intermittent hypoxemia may promote neovascularization and tumor growth in certain cancers, such as melanoma; (iii) obesity, present in majority of OSA patients, can be associated with a heightened proinflammatory state; (iv) upper airway obstruction due to local tumors or soft tissue swelling due to physical urticaria or angioedema; (v) acute nasal congestion in the atopic patient with allergic rhinitis; (vi) dermatologic disorders associated with other OSA risk factors (eg, acanthosis nigricans and metabolic syndrome); and (vii) a high sympathetic tone (eg, in atopic dermatitis) and resultant sleep fragmentation contributing to upper airway instability during sleep. In many instances, the dermatology patient with OSA may have other medical and psychiatric comorbidities that are also associated with increased OSA risk.

Inflammatory Events and Oxidant Production in the Diaphragm, Gastrocnemius, and Blood of Rats Exposed to Chronic Intermittent Hypoxia: Therapeutic Strategies

We hypothesized that inflammatory events and reactive oxygen species (ROS) production may be differentially expressed in respiratory and limb muscles, and blood of a chronic intermittent hypoxia (CIH) experimental model and that antioxidants and TNF-alpha blockade may influence those events. In blood, diaphragm, and gastrocnemius of rats non-invasively exposed to CIH (10% hypoxia, 2 h/day, 14 consecutive days) with/without concomitant treatment with either anti-TNF-alpha antibody (infliximab) or N-acetyl cysteine (NAC), inflammatory cytokines, superoxide anion production, muscle structural abnormalities, and fiber-type composition were assessed. Compared to non-exposed controls, in CIH-exposed rats, body weight gain was reduced, TNF-alpha, IL-1beta, IL-6, and interferon-gamma levels were increased in diaphragm, TNF-alpha, and IL-1 beta plasma levels were greater, systemic and muscle superoxide anion production was higher, diaphragm and gastrocnemius inflammatory cells and internal nuclei were higher, and muscle fiber-type and morphometry remained unmodified. CIH rats treated with infliximab further increased TNF-alpha, IL-1beta, IL-6, and interferon-gamma diaphragm levels, whereas NAC induced a reduction only in TNF-alpha and IL-1beta levels in diaphragm and plasma. Infliximab and NAC elicited a significant decline in superoxide anion production in diaphragm, gastrocnemius, and plasma, while inducing a further increase in inflammatory cells and internal nuclei in both muscles. Proinflammatory cytokines are differentially expressed in respiratory and limb muscles and plasma of CIH-exposed rats, while superoxide anion production increased in both muscle types and blood. Infliximab and NAC exerted different effects. These findings may help understand the biology underlying CIH in skeletal muscles and blood of patients with chronic respiratory diseases. J. Cell. Physiol. 232: 1165-1175, 2017. © 2016 Wiley Periodicals, Inc.