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

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.

Global research on cancer and sleep: A bibliometric and visual analysis of the last two decades

Objective

The study aimed to analyze the research status, hotspots, and frontiers of global research on cancer and sleep through bibliometrics and provide references and guidance for future research.

Methods

The literature regarding cancer and sleep from 2002 to 2022 was searched from the Web of Science Core Collection (WoSCC) database. CiteSpace 5.6.R3 was performed for visualization analysis.

Results

A total of 1,172 publications were identified. The number of publications in the field has gradually increased over the past two decades. The United States had the most prominent contributions. Taipei Medical University and the University of California, San Francisco, and David Gozal were the most prolific institutions and author, respectively. The most published academic journal was Supportive Care in Cancer. The research hotspots can be summarized into the symptom cluster intervention for cancer survivors and the association between cancer and melatonin and/or obstructive sleep apnea (OSA). The complex interaction between cancer and sleep disruption and the influencing factors of sleep quality may be the emerging trends of research.

Conclusion

This study systematically analyzed the hotspots and frontiers in the field of cancer and sleep and called for strengthening cooperation among countries, institutions, and authors. In addition, intervention measures for the cancer symptom cluster, the bioavailability of exogenous melatonin, the causal relationship between OSA and cancer, the mechanism of tumor-induced sleep disruption, the dose–response relationship between sleep duration and cancer risk, and the path relationship between sleep quality influencing factors may be the focus of future research.

The association between sleep quality and telomere length: A systematic literature review

Several sleep parameters present an elevated risk for processes that contribute to cellular aging. Short sleep duration, sleep apnoea, and insomnia are significantly associated with shorter telomeres, a biological marker of cellular aging. However, there has been no review or analysis of studies that have examined the association between the psychological construct of sleep quality and telomere length. The present study aimed to provide a systematic review of the association between sleep quality and telomere length. A systematic review of English articles was conducted using MEDLINE/PubMed, PsycINFO, Google Scholar, and Web of Science electronic databases, with the final search conducted on 3rd September 2021. Search terms included sleep quality, poor sleep, insomnia, sleep difficulties, sleep issue*, non-restorative sleep, telomere*, cellular aging, and immune cell telomere length. Study eligibility criteria included human participants aged 18 years or older and a reproducible methodology. Study appraisal and synthesis were completed using a systematic search in line with a PICOS approach (P = Patient, problem, or population; I = Intervention, prognostic factor, exposure; C = Comparison, control, or comparator; O = Outcomes; S = Study designs). Twenty-two studies met review inclusion criteria. Qualitative synthesis of the literature indicated insufficient evidence overall to support a significant association between sleep quality and telomere length. Limitations across studies were addressed, such as the assessment of examined constructs. Findings highlight important targets for future research, including the standardised operationalisation of the sleep quality construct and experimental study designs. Research in this area has clinical significance by identifying possible mechanisms that increase the risk for age-related disease and mortality. PROSPERO Registration No.: CRD 42021233139.

Genetic Variants of the TERT Gene and Telomere Length in Obstructive Sleep Apnea

Introduction: Obstructive sleep apnea (OSA) is a worldwide breathing disorder that has been diagnosed globally in almost 1 billion individuals aged 30−69 years. It is characterized by repeated upper airway collapses during sleep. Telomerase reverse transcriptase (TERT) is involved in the prevention of telomere shortening. This prospective, observational study aimed to investigate the relationship between single nucleotide polymorphisms (SNPs) of TERT and the severity of OSA, taking into account hypertension and diabetes prevalence. Methods: A total of 149 patients with OSA were diagnosed using one-night video-polysomnography based on the American Academy of Sleep Medicine guidelines. The TERT SNPs and telomere length (TL) were detected using real-time quantitative polymerase chain reaction. Results: Statistical analysis showed that there is no relationship between the rs2853669 and rs2736100 polymorphisms of TERT, and the severity of OSA (p > 0.05). Moreover, no relationship between TL and the severity of OSA was observed. The G allele in the locus of rs2736100 TERT was associated with hypertension prevalence and was more prevalent in hypertensives patients (46.00% vs. 24.49%, p = 0.011). The prevalence of hypertension was higher in patients with the C allele in the locus of rs2853669 than in patients without this allele (50.79% vs. 30.23%, p = 0.010). Moreover, a lower prevalence of diabetes was observed in homozygotes of rs2736100 TERT than in heterozygotes (5.63% vs. 15.38%, p = 0.039). Conclusion: This study showed no relationship between OSA and TERT SNPs. However, SNPs of the TERT gene (rs2736100 and rs2853669) were found to affect arterial hypertension and diabetes prevalence.

Effects of Intermittent Hypoxia in Training Regimes and in Obstructive Sleep Apnea on Aging Biomarkers and Age-Related Diseases: A Systematic Review

Several studies have assessed the effects of intermittent hypoxia-normoxia training (IHNT), intermittent hypoxia-hyperoxia training (IHHT), and obstructive sleep apnea (OSA) on aging and age-related diseases in humans; however, the results remain contradictory. Therefore, this review aims to systematically summarize the available studies on the effects of IHNT, IHHT, and OSA on aging and age-related diseases. Relevant studies were searched from PubMed, Google Scholar, Cochrane Library databases, and through manual searching from reference lists of eligible studies. A total of 38 eligible studies were included in this systematic review. IHHT and IHNT provide positive effects on several age-related parameters including quality of life, cognitive and physical functions, plasma level of glucose and cholesterol/LDL, systolic blood pressure, red blood cells, and inflammation. Moreover, moderate intermittent hypoxia induces telomerase reverse transcriptase (TERT) activity and telomere stabilization, delays induction of senescence-associated markers expression and senescence-associated β-galactosidase, upregulates pluripotent marker (Oct4), activates a metabolic shift, and raises resistance to pro-apoptotic stimuli. On the contrary, intermittent hypoxia in OSA causes hypertension, metabolic syndrome, vascular function impairment, quality of life and cognitive scores reduction, advanced brain aging, increase in insulin resistance, plasma hydrogen peroxide, GSH, IL-6, hsCRP, leptin, and leukocyte telomere shortening. Thus, it can be speculated that the main factor that determines the direction of the intermittent hypoxia action is the intensity and duration of exposure. There is no direct study to prove that IHNT/IHHT actually increases life expectancy in humans. Therefore, further study is needed to investigate the actual effect of IHNT/IHHT on aging in humans.

Systematic Review Registration

www.crd.york.ac.uk/prospero, identifier CRD42022298499.

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.

Three-dimensional craniofacial characteristics associated with obstructive sleep apnea severity and treatment outcomes

OBJECTIVES

This study aims to assess craniofacial dimensions in obstructive sleep apnea (OSA) patients treated with a mandibular advancement device (MAD) and to identify anatomic influences on OSA severity and MAD therapy outcomes.

MATERIALS AND METHODS

Twenty patients with OSA were prospectively treated with MAD. Clinical, cone-beam computed tomography, and polysomnography exams were performed before treatment and 4-6 months after achieving the MAD therapeutic position. Polysomnographic exams and three-dimensional maxillary, mandibular, and upper airway (UA) measurements were evaluated. Pearson's correlation and t-tests were applied.

RESULTS

Before MAD treatment, the transverse width measured at the frontomaxillary suture and the angle between the mandibular ramus and Frankfurt horizontal were statistically correlated with apnea and the hypopnea index (AHI), while the gonial angle was correlated with therapeutic protrusion. After MAD treatment, all patients showed a significant AHI reduction and an improvement in minimum oxyhemoglobin saturation. The UA total volume, superior and inferior oropharynx volume, and area were statistically correlated with MAD therapeutic protrusion. The UA total area showed a statistical correlation with the improvement in AHI, and the superior oropharynx volume and area increased significantly.

CONCLUSIONS

The transversal frontomaxillary suture width and the mandibular ramus facial angle may influence OSA severity. The gonial angle, volume, and area of all UA regions may indicate the amount of protrusion needed for successful MAD treatment.

CLINICAL RELEVANCE

The craniofacial characteristics reported as important factors for OSA severity and MAD treatment outcomes impact therapy planning for OSA patients, considering individual anatomic characteristics, prognosis, and cost benefits.

Obstructive Sleep Apnea as an Acceleration Trigger of Cellular Senescence Processes through Telomere Shortening

Obstructive sleep apnea (OSA) is chronic disorder which is characterized by recurrent pauses of breathing during sleep which leads to hypoxia and its two main pathological sequelae: oxidative stress and chronic inflammation. Both are also associated with cellular senescence. As OSA patients present with higher prevalence of age-related disorders, such as atrial hypertension or diabetes mellitus type 2, a relationship between OSA and accelerated aging is observable. Furthermore, it has been established that these OSA are associated with telomere shortening. This process in OSA is likely caused by increased oxidative DNA damage due to increased reactive oxygen species levels, DNA repair disruptions, hypoxia, chronic inflammation, and circadian clock disturbances. The aim of the review is to summarize study outcomes on changes in leukocyte telomere length (LTL) in OSA patients and describe possible molecular mechanisms which connect cellular senescence and the pathophysiology of OSA. The majority of OSA patients are characterized by LTL attrition due to oxidative stress, hypoxia and inflammation, which make a kind of positive feedback loop, and circadian clock disturbance.

The Human Blood Transcriptome in a Large Population Cohort and Its Relation to Aging and Health

Background: The blood transcriptome is expected to provide a detailed picture of an organism's physiological state with potential outcomes for applications in medical diagnostics and molecular and epidemiological research. We here present the analysis of blood specimens of 3,388 adult individuals, together with phenotype characteristics such as disease history, medication status, lifestyle factors, and body mass index (BMI). The size and heterogeneity of this data challenges analytics in terms of dimension reduction, knowledge mining, feature extraction, and data integration.

Methods: Self-organizing maps (SOM)-machine learning was applied to study transcriptional states on a population-wide scale. This method permits a detailed description and visualization of the molecular heterogeneity of transcriptomes and of their association with different phenotypic features.

Results: The diversity of transcriptomes is described by personalized SOM-portraits, which specify the samples in terms of modules of co-expressed genes of different functional context. We identified two major blood transcriptome types where type 1 was found more in men, the elderly, and overweight people and it upregulated genes associated with inflammation and increased heme metabolism, while type 2 was predominantly found in women, younger, and normal weight participants and it was associated with activated immune responses, transcriptional, ribosomal, mitochondrial, and telomere-maintenance cell-functions. We find a striking overlap of signatures shared by multiple diseases, aging, and obesity driven by an underlying common pattern, which was associated with the immune response and the increase of inflammatory processes.

Conclusions: Machine learning applications for large and heterogeneous omics data provide a holistic view on the diversity of the human blood transcriptome. It provides a tool for comparative analyses of transcriptional signatures and of associated phenotypes in population studies and medical applications.