Coherent Electron-Vibron Interactions in Surface-Enhanced Raman Scattering (SERS).

In this Letter we identify coherent electron-vibron interactions between near-resonant and nonresonant electronic levels that contribute beyond standard optomechanical models for off-resonant or resonance surface-enhanced Raman scattering (SERS). By developing an open-system quantum model using first molecular interaction principles, we show how the Raman interference of both resonant and nonresonant contributions can provide several orders of magnitude modifications of the SERS peaks with respect to former optomechanical models and over the fluorescence backgrounds. This cooperative optomechanical mechanism allows for generating an enhancement of nonclassical photon pair correlations between Stokes and anti-Stokes photons, which can be detected by photon-counting measurements. Our results demonstrate Raman enhancements and suppressions of coherent nature that significantly impact the standard estimations of the optomechanical contribution from SERS spectra and their quantum mechanical observable effects.

Obesity, sleep apnea, and cancer.

The interest on a potential association between cancer and sleep-disordered breathing (SDB) has clearly gained substantial traction over the last several years. This novel relationship was initially explored in experimental models of obstructive sleep apnea (OSA) and showed that both intermittent hypoxia and sleep fragmentation, the two main hallmarks of OSA, promoted alterations in both tumorigenesis and tumor malignant properties. In parallel, an intriguing role of obesity as a major interactive player in the relationship between cancer and OSA was postulated in the following contextual settings: (1) obesity (with or without OSA) is associated with increased risk of some types of cancer (both incidence and aggressiveness), whereas obesity could be protective for others ("obesity paradox"); (2) OSA has been associated with increased risk for some types of cancer (independent of obesity), but not with others; (3) More than 80% of adult patients with OSA are overweight and >50% are obese; (4) both OSA and obesity exhibit oscillations in tissue oxygen tensions in peripheral organs such as adipose tissues. Further understanding these complex relationships become all the more important considering that the prevalence of obesity, cancer and OSA are all increasing worldwide. In parallel, experimental models of OSA provide biological plausibility constructs to the clinical and epidemiological findings, suggesting that the metabolic and inflammatory changes induced by chronic intermittent hypoxia and sleep fragmentation may foster or exacerbate immune and biomechanical alterations of the tumor microenvironment, including the expression of extracellular matrix components facilitating tumor progression.

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.

Increased Incidence of Stroke, but Not Coronary Heart Disease, in Elderly Patients With Sleep Apnea.

Background and Purpose- The influence of age on the relationship between obstructive sleep apnea (OSA) and the incidence of hard cardiovascular events remains controversial. We sought to analyze the relationship between OSA and the incidence of stroke and coronary heart disease in a large cohort of elderly patients, as well as to investigate the role of continuous positive airway pressure (CPAP) treatment in these associations. Methods- Post hoc analysis of a prospective observational study of consecutive patients ≥65 years studied for OSA suspicion at 2 Spanish University Hospitals. Patients with an apnea-hypopnea index (AHI) <15 were the reference group. OSA was defined by an AHI ≥15 and classified as untreated (CPAP not prescribed or compliance <4 hours/day), mild-moderate (AHI 15-29), untreated severe (AHI ≥30), and CPAP-treated (AHI ≥15 and CPAP compliance ≥4 hours/day). Results- 859 and 794 elderly patients were included in the stroke and coronary heart disease analyses, respectively. The median (interquartile range) follow-up was 72 (50-88.5) and 71 (51.5-89) months, respectively. Compared with the reference group, the fully adjusted hazard ratios for the incidence of stroke were 3.42 (95% CI, 1.37-8.52), 1.02 (95% CI, 0.41-2.56), and 1.76 (95% CI, 0.62-4.97) for the untreated severe OSA group, CPAP-treated group, and untreated mild-moderate OSA group, respectively. No associations were shown between any of the different OSA groups and coronary heart disease incidence. Conclusions- The incidence of stroke, but not coronary heart disease, is increased in elderly patients with untreated severe OSA. Adequate CPAP treatment may reduce this risk.

Effect of continuous positive airway pressure on blood pressure and metabolic profile in women with sleep apnoea.

Continuous positive airway pressure (CPAP) reduces blood pressure levels in hypertensive patients with obstructive sleep apnoea (OSA). However, the role of CPAP in blood pressure and the metabolic profile in women has not yet been assessed. In this study we investigated the effect of CPAP on blood pressure levels and the glucose and lipid profile in women with moderate-to-severe OSA.A multicentre, open-label, randomised controlled trial was conducted in 307 women diagnosed with moderate-to-severe OSA (apnoea-hypopnoea index ≥15 events·h-1) in 19 Spanish Sleep Units. Women were randomised to CPAP (n=151) or conservative treatment (n=156) for 12 weeks. Changes in office blood pressure measures as well as in the glucose and lipid profile were assessed in both groups.Compared with the control group, the CPAP group achieved a significantly greater decrease in diastolic blood pressure (-2.04 mmHg, 95% CI -4.02- -0.05; p=0.045), and a nonsignificantly greater decrease in systolic blood pressure (-1.54 mmHg, 95% CI -4.58-1.51; p=0.32) and mean blood pressure (-1.90 mmHg, 95% CI -4.0-0.31; p=0.084). CPAP therapy did not change any of the metabolic variables assessed.In women with moderate-to-severe OSA, 12 weeks of CPAP therapy improved blood pressure, especially diastolic blood pressure, but did not change the metabolic profile, compared with conservative treatment.

Continuous Positive Airway Pressure Improves Quality of Life in Women with Obstructive Sleep Apnea. A Randomized Controlled Trial.

RATIONALE: Continuous positive airway pressure (CPAP) is the treatment of choice in patients with symptomatic obstructive sleep apnea (OSA). CPAP treatment improves quality of life (QoL) in men with OSA, but its role in women has not yet been assessed. OBJECTIVES: To investigate the effect of CPAP on QoL in women with moderate to severe OSA. METHODS: We conducted a multicenter, open-label randomized controlled trial in 307 consecutive women diagnosed with moderate to severe OSA (apnea-hypopnea index, ≥15) in 19 Spanish sleep units. Women were randomized to receive effective CPAP therapy (n = 151) or conservative treatment (n = 156) for 3 months. The primary endpoint was the change in QoL based on the Quebec Sleep Questionnaire. Secondary endpoints included changes in daytime sleepiness, mood state, anxiety, and depression. Data were analyzed on an intention-to-treat basis with adjustment for baseline values and other relevant clinical variables. MEASUREMENTS AND MAIN RESULTS: The women in the study had a mean (SD) age of 57.1 (10.1) years and a mean (SD) Epworth Sleepiness Scale score of 9.8 (4.4), and 77.5% were postmenopausal. Compared with the control group, the CPAP group achieved a significantly greater improvement in all QoL domains of the Quebec Sleep Questionnaire (adjusted treatment effect between 0.53 and 1.33; P < 0.001 for all domains), daytime sleepiness (-2.92; P < 0.001), mood state (-4.24; P = 0.012), anxiety (-0.89; P = 0.014), depression (-0.85; P = 0.016), and the physical component summary of the 12-item Short Form Health Survey (2.78; P = 0.003). CONCLUSIONS: In women with moderate or severe OSA, 3 months of CPAP therapy improved QoL, mood state, anxiety and depressive symptoms, and daytime sleepiness compared with conservative treatment. Clinical trial registered with www.clinicaltrials.gov (NCT02047071).

Role of sleep apnea and continuous positive airway pressure therapy in the incidence of stroke or coronary heart disease in women.

RATIONALE: It is unknown whether obstructive sleep apnea (OSA) may be a risk factor for incident cardiovascular events in women. OBJECTIVES: We sought to investigate whether OSA increases the incidence of a composite of stroke or coronary heart disease (CHD) in women, and the role of continuous positive airway pressure (CPAP) treatment on this association. METHODS: This was a prospective, observational study conducted in two Spanish teaching hospitals between 1998 and 2007. Consecutive women referred for suspected OSA and free of previous stroke and CHD were analyzed. Women with an apnea-hypopnea index (AHI) less than 10 comprised the control group, and those with an AHI greater than or equal to 10 were diagnosed with OSA and classified as CPAP-treated (adherence ≥ 4 h/d) or untreated (adherence < 4 h/d or not prescribed). The follow-up ended in December 2010. MEASUREMENTS AND MAIN RESULTS: A total of 967 women were studied (median follow-up, 6.8 yr; interquartile range, 5.2-8.2). The untreated OSA group showed a greater incidence rate of the composite outcome than the control group (2.19 vs. 0.54 per 100 person-years; P < 0.0005). Compared with the control group, the fully adjusted hazard ratios for the composite outcome incidence were 2.76 (95% confidence interval [CI], 1.35-5.62) for the untreated OSA group, and 0.91 (95% CI, 0.43-1.95) for the CPAP-treated group. When the type of cardiovascular event was separately assessed, untreated OSA showed a stronger association with incident stroke (adjusted hazard ratio, 6.44; 95% CI, 1.46-28.3) than with CHD (adjusted hazard ratio, 1.77; 95% CI, 0.76-4.09). CONCLUSIONS: In women, untreated OSA is associated with increased incidence of serious cardiovascular outcomes, particularly incident stroke. Adequate CPAP treatment seems to reduce this risk.

Multidimensional approach to non-cystic fibrosis bronchiectasis: the FACED score.

Bronchiectasis is a multidimensional disease and, therefore, its severity or prognosis cannot be adequately quantified by analysing one single variable. The objective of the present study was to develop a multidimensional score that classifies the severity of bronchiectasis according to its prognosis. This is an observational multicentre study including 819 patients diagnosed with non-cystic fibrosis bronchiectasis using high-resolution computed tomography. 397 subjects were selected at random to construct the score while the remaining 422 were used for its validation. The outcome was 5-year all-cause mortality after radiological diagnosis. A logistic regression analysis was used to select the variables included in the final score. The final seven-point score incorporated five dichotomised variables: forced expiratory volume in 1 s % predicted (F, cut-off 50%, maximum value 2 points); age (A, cut-off 70 years, maximum value 2 points); presence of chronic colonisation by Pseudomonas aeruginosa (C, dichotomic, maximum value 1 point); radiological extension (E, number of lobes affected, cut-off two lobes, maximum value 1 point); and dyspnoea (D, cut-off grade II on the Medical Research Council scale, maximum value 1 point) to construct the FACED score. The validation cohort confirmed the score's validity. We conclude that this easy-to-use multidimensional grading system proved capable of accurately classifying the severity of bronchiectasis according to its prognosis.

Association between obstructive sleep apnea and cancer incidence in a large multicenter Spanish cohort.

RATIONALE: Obstructive sleep apnea (OSA) has been associated with increased cancer mortality, but whether it is also associated with cancer incidence is unknown. OBJECTIVES: To investigate whether OSA is associated with increased cancer incidence in a large clinical cohort. METHODS: A multicenter, clinical cohort study including consecutive patients investigated for suspected OSA between 2003 and 2007 in seven Spanish teaching hospitals. Apnea-hypopnea index (AHI) and percent nighttime with oxygen saturation less than 90% (TSat(90)) were used as surrogates of OSA severity, both as continuous variables and categorized by tertiles. Cox proportional hazards regression analyses were used to calculate hazard ratio (HR) and 95% confidence interval (CI) for cancer incidence after adjusting for confounding variables. MEASUREMENTS AND MAIN RESULTS: A total of 4,910 patients were analyzed (median follow-up, 4.5 yr; interquartile range, 3.4-5.2). Compared with the lower TSat(90) category (<1.2%), the adjusted hazards (95% CI) of cancer incidence for increasing categories were 1.58 (1.07-2.34) for TSat(90) 1.2-12% and 2.33 (1.57-3.46) for TSat(90) greater than 12%. Continuous TSat(90) was also associated with cancer incidence (adjusted HR, 1.07 [1.02-1.13] per 10-unit increase in TSat(90)). In stratified analyses, TSat(90) was associated with cancer incidence in patients younger than 65 years (adjusted HR, 1.13 [95% CI, 1.06-1.21] per 10-unit increase in TSat(90)) and males (adjusted HR, 1.11 [95% CI, 1.04-1.17] per 10-unit increase in TSat(90)). AHI was not associated with cancer incidence in the adjusted analyses, except for patients younger than 65 years (adjusted HR for AHI >43 vs. <18.7, 1.66; 95% CI, 1.04-2.64). CONCLUSIONS: Increased overnight hypoxia as a surrogate of OSA severity was associated with increased cancer incidence. This association seems to be limited to men and patients younger than 65 years of age.

Long-term continuous positive airway pressure compliance in females with obstructive sleep apnoea.

Continuous positive airway pressure (CPAP) is the treatment of choice for obstructive sleep apnoea (OSA), but compliance and variables involved in long-term CPAP adherence in females with OSA are unknown. We performed an observational study including all consecutive females diagnosed with CPAP who started CPAP treatment in two Spanish teaching hospitals between 1999 and 2007 and were followed-up until December 2010. The Kaplan-Meier method was used to calculate the probability of continuing with CPAP treatment and a multivariate Cox regression analysis was used to identify baseline predictors of CPAP dropout. We analysed 708 females, median (interquartile range) age 60 (52-67) years and apnoea-hypopnoea index 43.0 (27.2-66.8). Females were followed for a median of 6.2 (4.2-7.7) years. The probability of still being on CPAP at 5 and 10 years was 82.8% and 79.9%, respectively. The median CPAP use was 6 (interquartile range 4-7) h · day(-1). In the multivariate analysis, independent baseline predictors of CPAP dropout were psychoactive medication (hazard ratio 1.47, 95% CI 1.03-2.08), age (hazard ratio 1.01, 95% CI 1.00-1.03) and CPAP pressure (hazard ratio 0.89, 95% CI 0.81-0.96). Long-term CPAP adherence in females with OSA is good. Psychoactive medication and increasing age were independent predictors of CPAP dropout, whereas higher CPAP was associated with continued treatment.

Cardiovascular mortality in women with obstructive sleep apnea with or without continuous positive airway pressure treatment: a cohort study.

BACKGROUND: Obstructive sleep apnea (OSA) is a risk factor for cardiovascular death in men, but whether it is also a risk factor in women is unknown. OBJECTIVE: To investigate whether OSA is a risk factor for cardiovascular death in women and assess whether continuous positive airway pressure (CPAP) treatment is associated with a change in risk. DESIGN: Prospective, observational cohort study. SETTING: 2 sleep clinics in Spain. PATIENTS: All women consecutively referred for suspected OSA between 1998 and 2007. INTERVENTION: Every woman had a diagnostic sleep study. Women with an apnea-hypopnea index (AHI) less than 10 were the control group. Obstructive sleep apnea was diagnosed when the AHI was 10 or higher (classified as mild to moderate [AHI of 10 to 29] or severe [AHI ≥30]). Patients with OSA were classified as CPAP-treated (adherence ≥4 hours per day) or untreated (adherence <4 hours per day or not prescribed). Participants were followed until December 2009. MEASUREMENTS: The end point was cardiovascular death. RESULTS: 1116 women were studied (median follow-up, 72 months [interquartile range, 52 to 88 months]). The control group had a lower cardiovascular mortality rate (0.28 per 100 person-years [95% CI, 0.10 to 0.91]) than the untreated groups with mild to moderate OSA (0.94 per 100 person-years [CI, 0.10 to 2.40]; P = 0.034) or severe OSA (3.71 per 100 person-years [CI, 0.09 to 7.50]; P < 0.001). Compared with the control group, the fully adjusted hazard ratios for cardiovascular mortality were 3.50 (CI, 1.23 to 9.98) for the untreated, severe OSA group; 0.55 (CI, 0.17 to 1.74) for the CPAP-treated, severe OSA group; 1.60 (CI, 0.52 to 4.90) for the untreated, mild to moderate OSA group; and 0.19 (CI, 0.02 to 1.67) for the CPAP-treated, mild to moderate OSA group. LIMITATION: The study was observational and not randomized, and OSA was diagnosed by 2 different methods. CONCLUSION: Severe OSA is associated with cardiovascular death in women, and adequate CPAP treatment may reduce this risk. PRIMARY FUNDING SOURCE: None.

Hypoxic Burden in Obstructive Sleep Apnea: Present and Future.

Conventional measures of obstructive sleep apnea (OSA) severity, such as the apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) are commonly used to quantify OSA severity and guide therapeutical decision-making processes. However, it is widely recognized that both AHI and ODI have important limitations and novel physiologically-informed metrics are needed to better capture the severity of OSA and characterize its physiological consequences, particularly the severity of recurrent nocturnal hypoxemia, ensuing the respiratory events. According to recent studies, the sleep apnea-specific "hypoxic burden (HB)", defined as the sum of individual areas under the oxygen desaturation curve, has shown some promise in identifying high risk individuals with OSA. In addition to the frequency of respiratory events, HB capture the depth and duration of OSA-related hypoxemia that may prove to be important disease characterizing features, not captured by the conventional "frequency-based" metrics, such as AHI and ODI. In this "perspective" paper the methods to quantify the HB, its characteristics, associations with health outcomes, and its limitations will be discussed.

WITHDRAWN: Hypoxic Burden in Obstructive Sleep Apnea: Present and Future.

The Publisher regrets that this article is an accidental duplication of an article that has already been published, https://doi.org/10.1016/j.arbres.2022.08.005. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/policies/article-withdrawal

Biological Biomarkers in Respiratory Diseases. / Biomarcadores biológicos en las enfermedades respiratorias.

In recent years, personalized or precision medicine has made effective inroads into the management of diseases, including respiratory diseases. The route to implementing this approach must invariably start with the identification and validation of biological biomarkers that are closely related to the diagnosis, treatment, and prognosis of respiratory patients. In this respect, biological biomarkers of greater or lesser reliability have been identified for most respiratory diseases and disease classes, and a large number of studies are being conducted in the search for new indicators. The aim of this review is to update the reader and to analyze the existing scientific literature on the existence and diagnostic, therapeutic, and prognostic validity of the most important biological biomarkers in the main respiratory diseases, and to identify future challenges in this area.

Heterogeneity of Melanoma Cell Responses to Sleep Apnea-Derived Plasma Exosomes and to Intermittent Hypoxia.

Obstructive sleep apnea (OSA) is associated with increased cutaneous melanoma incidence and adverse outcomes. Exosomes are secreted by most cells, and play a role in OSA-associated tumor progression and metastasis. We aimed to study the effects of plasma exosomes from OSA patients before and after adherent treatment with continuous positive airway pressure (CPAP) on melanoma cells lines, and also to identify exosomal miRNAs from melanoma cells exposed to intermittent hypoxia (IH) or normoxia. Plasma-derived exosomes were isolated from moderate-to-severe OSA patients before (V1) and after (V2) adherent CPAP treatment for one year. Exosomes were co-incubated with three3 different melanoma cell lines (CRL 1424; CRL 1619; CRL 1675) that are characterized by genotypes involving different mutations in BRAF, STK11, CDKN2A, and PTEN genes to assess the effect of exosomes on cell proliferation and migration, as well as on pAMK activity in the presence or absence of a chemical activator. Subsequently, CRL-1424 and CRL-1675 cells were exposed to intermittent hypoxia (IH) and normoxia, and exosomal miRNAs were identified followed by GO and KEG pathways and gene networks. The exosomes from these IH-exposed melanoma cells were also administered to THP1 macrophages to examine changes in M1 and M2 polarity markers. Plasma exosomes from V1 increased CRL-1424 melanoma cell proliferation and migration compared to V2, but not the other two cell lines. Exposure to CRL-1424 exosomes reduced pAMPK/tAMPK in V1 compared to V2, and treatment with AMPK activator reversed the effects. Unique exosomal miRNAs profiles were identified for CRL-1424 and CRL-1675 in IH compared to normoxia, with six miRNAs being regulated and several KEGG pathways were identified. Two M1 markers (CXCL10 and IL6) were significantly increased in monocytes when treated with exosomes from IH-exposed CRL-1424 and CRL-1625 cells. Our findings suggest that exosomes from untreated OSA patients increase CRL-1424 melanoma malignant properties, an effect that is not observed in two other melanoma cell lines. Exosomal cargo from CRL-1424 cells showed a unique miRNA signature compared to CRL-1675 cells after IH exposures, suggesting that melanoma cells are differentially susceptible to IH, even if they retain similar effects on immune cell polarity. It is postulated that mutations in STK-11 gene encoding for the serine/threonine kinase family that acts as a tumor suppressor may underlie susceptibility to IH-induced metabolic dysfunction, as illustrated by CRL-1424 cells.