Airway Pressure Research Articles

Sleep Disorders and Dementia Risk in Older Patients with Kidney Failure: A Retrospective Cohort Study.

Community-dwelling older adults with sleep disorders are at higher risk of developing dementia. Greater than 50% of older patients with kidney failure experience sleep disorders, which may explain their high burden of dementia. Among 216,158 patients (age ≥66 years) with kidney failure (United States Renal Data System; 2008-2019), we estimated the risk of dementia (including subtypes) associated with sleep disorders using Cox proportional-hazard models with propensity score weighting. We tested whether positive airway pressure (PAP) therapy was associated with reduced dementia risk among patients with obstructive sleep apnea (OSA). 26.3% of patients were diagnosed with sleep disorders; these patients had a higher five-year unadjusted cumulative incidence for any type of dementia (36.2% vs. 32.3%; P<0.001), vascular dementia (4.4% vs. 3.7%; P<0.001), and other/mixed dementia (29.3% vs. 25.8%; P<0.001). Higher risk of any type of dementia was identified in patients with insomnia (aHR=1.42; 95%CI: 1.34-1.51), sleep-related breathing disorders (SRBDs) (aHR=1.20; 95%CI: 1.17-1.23), and other sleep disorders (aHR=1.24; 95%CI: 1.11-1.39). Higher vascular dementia risk was observed in patients with insomnia (aHR=1.43; 95%CI: 1.19-1.73), SRBDs (aHR=1.15; 95%CI: 1.07-1.24). Patients with SRBDs (aHR=1.07; 95%CI: 1.00-1.15) were at higher risk of Alzheimer's disease. Among patients with OSA, PAP therapy was associated with lower risk for any type of dementia (aHR=0.82; 95%CI: 0.76-0.90), and vascular dementia (aHR=0.65; 95%CI: 0.50-0.85). Older patients with kidney failure and sleep disorders are at a higher risk of dementia. Sleep is an important modifiable factor that should be considered for targeted interventions to mitigate dementia risk in patients with kidney failure. For patients with OSA, PAP therapy is associated with lower dementia risk.

Effects of Positive Airway Pressure on Cardiorespiratory Fitness in Patients with Concomitant Obstructive Sleep Apnea and Cardiovascular Disease

Background and Objectives: Obstructive sleep apnea (OSA) is common in cardiovascular disease (CVD), although positive airway pressure (PAP) treatment has not been demonstrated to improve the cardiovascular outcome. The objective of this study is to investigate the impact of adherence to PAP therapy on cardiopulmonary exercise testing (CPET) performance in patients with concomitant OSA and CVD. Materials and Methods: This preliminary study involved symptomatic OSA patients requiring PAP treatment who had CVD. All subjects underwent polysomnography, echocardiography, and CPET at baseline. After 6 to 12 months of PAP treatment, CPET performance was re-assessed. The changes in CPET parameters before and after PAP treatment were compared between patients who were adherent to PAP and patients who were not adherent to PAP. Results: A total of 16 OSA patients with an apnea–hypopnea index of 32.0 ± 23.4 were enrolled. Patients were classified into the adherent (n = 9) and non-adherent (n = 7) groups with regard to PAP adherence. After 6 to 12 months of PAP treatment, the PAP-adherent group showed a greater increase in peak VO2 than the PAP-non-adherent group, but the difference between the two groups was not significant (p = 0.581). The decrease in ventilatory equivalent for the carbon dioxide slope (VE/VCO2) was significantly greater in the PAP-adherent group compared to the PAP-non-adherent group (p = 0.030). Conclusions: Adherence to PAP therapy for OSA is associated with an improvement in the VE/VCO2 slope, as an index of the ventilatory response to exercise, in patients with CVD. Screening for sleep apnea in CVD patients may be warranted, and strategies to optimize adherence to PAP in these patients are beneficial. Further evidence is needed to elucidate whether CPET could be routinely used to monitor treatment responses of OSA to PAP therapy in patients with CVD.

Non-invasive high-frequency oscillatory ventilation (NHFOV) versus nasal continuous positive airway pressure (NCPAP) for preterm infants: a systematic review and meta-analysis

ObjectiveTo compare the efficacy and safety of non-invasive high-frequency oscillatory ventilation (NHFOV) and nasal continuous positive airway pressure (NCPAP) in preterm infants.DesignThe study conducted a comprehensive analysis across three databases,...

Early Bubble CPAP Protocol Implementation and Rates of Death or Severe BPD.

A multidisciplinary comprehensive protocol to use bubble continuous positive airway pressure (bCPAP) as the primary respiratory support in the delivery room (DR) and the NICU was introduced. With this study, we aimed to assess the association of this change with respiratory outcomes over time. Infants with gestational age <32 weeks and birth weight <1250 g admitted between January 2012 and June 2020 were included and categorized into 4 periods, including pre-implementation (P0: 2012-2014), and post-implementation (P1: 2014-2016, P2: 2016-2018, P3: 2018-2020). The primary outcome was the rates of death and severe bronchopulmonary dysplasia (BPD), and the secondary outcomes included the rates of DR and NICU intubation ≤7 days of age, need of surfactant, and pneumothorax. Multivariate logistic regression models accounting for relevant risk factors were used to calculate adjusted odds ratios (ORs). The study included 440 infants (P0 = 90, P1 = 91, P2 = 128, P3 = 131). Over time, more infants were free of BPD (P < .001), and the rates of death and severe BPD decreased significantly: P1 = OR 1.21 (95% confidence interval [CI] 0.56-2.67), P2 = OR 0.45 (95% CI 0.20-0.99), and P3 = OR 0.37 (95% CI 0.15-0.84). DR intubation decreased from 66% (P0) to 24% (P3) in the entire cohort (P < .001) and from 96% (P0) to 40% (P3) in infants <26 weeks of age (P < .001). The need for NICU intubation was similar (P = .98), with a decreased need for surfactant (P = .001) occurring at higher FiO2 (P0 = 0.35 vs P3 = 0.55, P < .001). Pneumothorax rates were unchanged. In very preterm infants, the implementation of a comprehensive bCPAP protocol led to a significant and consistent improvement in respiratory practices and the rates of death and severe BPD.

Is the sFlt-1/PlGF ratio efficient in predicting adverse neonatal outcomes in small-for-gestational-age newborns? A prospective observational multicenter cohort study.

Fetuses with growth abnormalities are at an increased risk of adverse neonatal outcomes. The aim of this study was to investigate if placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), or the sFlt-1/PlGF ratio were efficient predictive factors of adverse neonatal outcomes in small-for-gestational-age (SGA) newborns. A prospective observational multicenter cohort study was performed between 2020 and 2023. At the time of the SGA fetus diagnosis, serum angiogenic biomarker measurements were performed. The primary outcome was an adverse neonatal outcome, diagnosed in the case of any of the following: <34 weeks of gestation: mechanical ventilation, sepsis, necrotizing enterocolitis, intraventricular hemorrhage grade III or IV, and neonatal death before discharge; ≥34 weeks of gestation: Neonatal Intensive Care Unit hospitalization, mechanical ventilation, continuous positive airway pressure, sepsis, necrotizing enterocolitis, intraventricular hemorrhage grade III or IV, and neonatal death before discharge. In total, 192 women who delivered SGA newborns were included in the study. The serum concentrations of PlGF were lower, leading to a higher sFlt-1/PlGF ratio in the adverse outcome group. No significant differences in sFlt-1 levels were observed between the groups. Both PlGF and sFlt-1 had a moderate correlation with adverse neonatal outcomes (PlGF: R - 0.5, p < 0.001; sFlt-1: 0.5, p < 0.001). The sFlt-1/PlGF ratio showed a correlation of 0.6 (p < 0.001) with adverse outcomes. The uterine artery pulsatility index (PI) and the sFlt-1/PlGF ratio were identified as the only independent risk factors for adverse outcomes. An sFlt-1/PlGF ratio of 19.1 exhibited high sensitivity (85.1%) but low specificity (35.9%) in predicting adverse outcomes and had the strongest correlation with them. This ratio allowed the risk of adverse outcomes to be assessed as low with approximately 80% certainty. The sFlt-1/PlGF ratio seems to be an efficient predictive tool in adverse outcome risk assessment. More studies on large cohorts of SGA-complicated pregnancies with and without preeclampsia are needed to develop an optimal and detailed formula for the risk assessment of adverse outcomes in SGA newborns.

Management of sleep-disordered breathing in patients with syndromic hemifacial macrosomia.

Patients with syndromic hemifacial microsomia (SHFM) are at risk of obstructive sleep apnea (OSA). The aim of the study was to describe the prevalence of OSA and its management, especially in patients with Goldenhar syndrome (GS). The respiratory polygraphies and clinical management of 15 patients, aged 2 to 23years, evaluated at a national reference center, were analyzed. Four (27%) patients had no OSA, 4 (27%) had mild OSA, and 7 (46%), of whom 5 were ≤ 2years old, had severe OSA. None of the patients had central apneas. Only one patient had alveolar hypoventilation, and another one had nocturnal hypoxemia. Two patients had severe OSA despite prior adenoidectomy or mandibular distraction osteogenesis. Median duration of follow-up was 3.5years (range 0.5-9years). None of the patients without OSA or with mild OSA at baseline respiratory polygraphy developed OSA during the follow up. Among the 7 patients with severe OSA, 3 required continuous positive airway pressure or noninvasive ventilation, and one patient required a tracheostomy. In conclusion, patients with SHFM are at high risk of severe OSA at any age, underlining the importance of systematic sleep studies to diagnose and evaluate the severity of OSA. Individualized treatment should be privileged, based on a careful examination of the entire upper airway, taking in account potential associated risk factors. All patients with SHFM should be managed by a pediatric expert multidisciplinary medical/surgical team until the end of post pubertal growth.

Comparison of high flow nasal cannula therapy to nasal oxygen as a treatment for obstructive sleep apnea in infants.

Obstructive sleep apnea (OSA) in infants is treated with low flow oxygen via nasal cannula (NC), CPAP (continous positive airway pressure), or surgery. Literature supports the use of high flow NC (HFNC) in children in the outpatient setting, however there is limited data on the use of HFNC in infants. The purpose of this study was to compare HFNC and low-flow oxygen as treatments for OSA in infants. A prospective pilot study was performed at two institutions. Infants with primarily OSA underwent a 3-4 h sleep study with HFNC titration at 6-14 lpm for OSA, followed by clinical polysomnography (PSG) for oxygen titration (1/8-1 lpm). Infants with primarily central apnea were excluded. Nine infants were enrolled, with a mean age of 1.3 ± 1.7 months. Average apnea hypopnea index (AHI), average obstructive apnea hypopnea index (OAHI) and average central apnea index during the diagnostic PSG was 17.2 ± 7/h, 13.4 ± 5.4/h and 3.7 ± 4.8/h respectively. OSA improved in 44.4% of subjects with HFNC; the mean AHI and OAHI decreased from 15.6 ± 5.65/h and 12.8 ± 4.4/h on diagnostic PSG to 5.12 ± 2.5/h and 4.25 ± 2.5/h on titration PSG. OSA improved universally with low flow oxygen; the mean AHI decreased from 17.2 ± 7/h on diagnostic PSG to 4.44 ± 3.6/h on titration PSG. HFNC reduced OSA in some infants, though low flow oxygen reduced OSA in all subjects. Respiratory instability (high loop gain) in infants may explain why infants responded to low flow oxygen. More studies are needed to determine if HFNC is beneficial in selected groups of infants with OSA.

Lung ultrasound for prediction of surfactant requirement in Indian preterm neonates: a diagnostic accuracy study.

Surfactant replacement for respiratory distress syndrome (RDS) is currently guided by oxygen (FiO2) requirement in preterm neonates. Lung ultrasound (LUS) has emerged as an important predictive tool; however, there is a paucity of evidence from developing countries.The objective of this study was to determine the diagnostic accuracy of the LUS score in comparison to standard criteria based on FiO2 requirement for prediction of surfactant requirement.In this prospective study, preterm neonates of < 34 weeks' gestation with RDS were included within 2 h of life. Surfactant was administered if the FiO2 requirement exceeded 30%. Baseline characteristics, respiratory parameters, and LUS clips were recorded soon after birth and compared between the surfactant and non-surfactant groups. LUS scoring was later performed by masked assessors which was not used in the management of neonates.Among 82 neonates (mean gestation 30.6 weeks and weight 1375 g) included in the study, 33 (40.2%) received surfactant. The surfactant group had a higher Silverman score, required higher FiO2 and mean airway pressure, and needed invasive ventilation more frequently. The mean (± SD) LUS score was significantly higher in the surfactant (9.4 ± 3.2) compared to the non-surfactant group (5.1 ± 2.1). The diagnostic accuracy of LUS scoring was determined by ROC curve analysis (AUC (95% CI): 0.83 (0.74-0.92), p < 0.01). A cutoff score of ≥ 8 for LUS was considered optimal for the prediction of surfactant requirement (sensitivity and specificity (95% CI) of 70% (51-84) and 80% (66-90), respectively). Conclusion:Lung ultrasound is a valid diagnostic tool for the prediction of surfactant requirements in resource-limited settings. What is Known: • Lung ultrasound has a good diagnostic accuracy in predicting the need for surfactant administration in preterm neonates in developed countries, but its role in developing countries is unclear. What is New: • Lung ultrasound proved to be a valid diagnostic tool in predicting surfactant replacement therapy in resource-limited settings. • The diagnostic performance of lung ultrasound was better in neonates on non-invasive ventilation, compared to invasive ventilation.

Automated oxygen titration with non-invasive ventilation in hypoxaemic adults with cardiorespiratory disease: a randomised cross-over trial

BackgroundClosed-loop oxygen control systems automatically adjust the fraction of inspired oxygen (FiO2) to maintain oxygen saturation (SpO2) within a predetermined target range. Their performance with low and high-flow oxygen therapies,...

Innate immune responses are increased in children with acute asthma exacerbation.

Little is known about the immune responses during acute asthma exacerbation. In this study, we examined immune responses in children following an acute asthma exacerbation. We evaluated pro-inflammatory cytokine levels and gene expression profiles in blood samples from pediatric patients admitted for acute asthma exacerbation. Viral PCR was performed to differentiate between viral or non-viral-associated exacerbations. Following informed consent, clinical data were obtained from 20 children with asthma (median [interquartile range, IQR]: age 11.5 [8.0, 14.2]) years and 14 healthy age-matched controls (10.5 [7.0, 13.0]). Twelve had positive nasopharyngeal Polymerase chain reaction (PCR) for viral infection (11 rhinoviruses and 1 respiratory syncytial virus (RSV)). Nine were in the pediatric intensive care unit (PICU) and among them five required continuous positive airway pressure (CPAP). Mean (±SD) days on systemic steroids before drawing blood sample were 2.5 ± 1.6. Twelve had history of environmental allergies with 917 (274, 1396) IU/mL total IgE (median (IQR)). Compared with controls, IL-1RA and IL-10 levels were significantly increased and TNF-α significantly decreased in asthma subjects (p < .05 for all). RNA-seq analysis revealed 852 differentially expressed genes in subjects with asthma. Pathway analysis found upregulated genes and pathways involved in innate immune responses in subjects with asthma. Significantly reduced genes included pathways associated with T helper cell differentiation and activation. In acute asthma exacerbation, innate immune pathways remained increased while adaptive immune responses related to T helper cells are blunted and are independent of trigger or asthma severity. Our novel findings highlight the need to identify new therapies to target persistent innate immune responses to improve outcomes in acute asthma.

Management of obstructive sleep apnoea in primary care.

Obstructive sleep apnoea (OSA) is common in the community and is increasing in prevalence. Primary care plays a pivotal role in the diagnosis and management of OSA. This article focuses on the management options for a patient with an established diagnosis of OSA and provides a guide for driving licensing requirements. Indications for continuous positive airway pressure (CPAP) are discussed and tips provided toconsider when conducting a review appointment, including trouble shooting. There are several treatment options available for patients with an established diagnosis of OSA. Selecting the optimal therapy involves aligning the symptoms and severity of OSA with the presence of comorbidities. CPAP is a highly effective therapy for symptomatic adults with moderate-to-severe OSA and for some symptomatic patients with mild OSA. Early trouble shooting of side effects and using supportive interventions increases the probability of long-term adherence, which is key to symptomatic improvement.

Safety and efficacy of continuous intrathecal baclofen via cervical catheter tip: a retrospective case series.

Intrathecal baclofen (ITB) is an effective treatment for hypertonia in children involving the implantation of a pump and catheter system. The highest concentration of ITB is at the catheter tip. The catheter tip location is most commonly within the lumbar or thoracic spine. The cervical tip location has traditionally been avoided because of concerns of hypoventilation and pneumonia; however, these complications in cervical compared with thoracic or lumbar placement have not been reliably proven. Some studies have suggested that cervical ITB location better treats upper-extremity hypertonia. There are limited data describing the safety and efficacy of cervical ITB on hypertonia. The authors present a single-institution retrospective case series highlighting the safety and efficacy of using cervical ITB location for the treatment of hypertonia. Retrospective data analysis was performed for children who underwent continuous dosing cervical ITB between April 2022 and October 2023. Nonmodifiable risk factors, clinical variables, operative characteristics, and adverse outcomes were collected. This study included 25 patients (8 female). The mean age at implantation was 12.4 years, and the mean operative duration was 90 minutes. The mean Barry-Albright Dystonia Scale score decreased by 9.5 points (p = 0.01). The mean aggregated modified Ashworth scale score in the upper extremities decreased by 2.14 points (p = 0.04), and that in the lower extremities decreased by 4.98 points (p < 0.01). One patient each (4%) had infection and baclofen toxicity. Two patients (8%) had respiratory depression requiring continuous positive airway pressure. There was no incidence of pneumonia or wound dehiscence. The cervical catheter tip location for ITB is safe, is effective to control tone, and should be considered for the treatment of hypertonia. Larger studies with longer follow-up are necessary to further determine upper-limit dosing safety along with long-term functional benefits in these patients.

Early Adverse Respiratory Outcomes in Obese Pediatric Tonsillectomy Patients.

To determine if body mass index (BMI) is predictive of adverse respiratory events (ARE) in the obese pediatric population undergoing tonsillectomy. Case series with chart review. Single institution academic otolaryngology practice. All patients 3 to 12 years old with BMI ≥95th percentile that underwent tonsillectomy March 1, 2011 to July 15, 2020 were included. The study excluded patients with comorbidities that warranted admission independent of BMI, including Trisomy 21, gross developmental delay, neuromuscular disorders, and congenital heart disease. Perioperative AREs following tonsillectomy were recorded. AREs were defined as postoperative desaturation (SpO2 < 90%), intubation, continuous positive airway pressure (CPAP), or new O2 requirement for >2 hours. Eighteen patients (8%) had at least 1 ARE. There were no children age 5 and older with a BMI 95th percentile to 98.9th percentile who had an early adverse respiratory outcome. Preoperative polysomnogram (PSG) metrics, obstructive apnea-hypopnea index (oAHI), and oxygen saturations (SpO2) nadir was significantly different between patients with and without AREs (mean oAHI 54.3 vs 17.4, P = .02; mean SpO2 nadir 73.1% vs 84.5%, P = .05). There was no significant difference in the BMI z score (2.88 vs 2.45, P = .09) between groups. AREs requiring inpatient management are uncommon in obese children after tonsillectomy. BMI is a poor independent indication for admission except at BMI extremes. We found significantly higher oAHI and lower SpO2 nadir on PSG indicate a higher risk for AREs and can guide admission postoperatively. There may be a subset of obese tonsillectomy patients who can be safely discharged home on the day of surgery.

Respiratory polygraphy in children with bronchopulmonary dysplasia: a retrospective study.

Periodic assessment of the need for oxygen supplementation and/or mechanical ventilation in children with severe bronchopulmonary dysplasia (BPD) is crucial. The aim of the study was to analyze the indications and results of respiratory polygraphies (RP) performed in preterm infants with BPD followed at a tertiary university hospital. All subjects <5-year-old with BPD who had a RP between September and February 2018 were included. The indications and results of RP and consequent medical management were analyzed. Fourteen infants (9 females, mean gestational age 27.6±3.3 weeks) underwent a RP at mean age of 26.4±19.4 months. Five subjects were evaluated for the need of long-term respiratory support (RS), 3 started continuous positive airway pressure (CPAP), 2 were weaned from RS. Four subjects underwent RP for suspected obstructive sleep apnea (OSA), one started on CPAP. Central apnea syndrome (CSA) was confirmed in 2 subjects and one was started on non-invasive ventilation. RP allowed safe tracheostomy decannulation in 2 subjects. Finally, RP was normal in one subject who had a brief resolved unexplained event. RP represents an important tool for the evaluation of children with BPD and leads to important therapeutic decisions.

Association between healthy behaviors and healthcare resource use with subsequent positive airway pressure therapy adherence in obstructive sleep apnoea.

BackgroundThe healthy adherer effect (HAE) has gained increasing attention as potential source of bias in observational studies examining the association of positive airway pressure (PAP) adherence with health outcomes in obstructive sleep apnea (OSA). Research questionIs adherence to PAP associated with healthy behaviors and healthcare resource use prior to device prescription? MethodsData from the IRSR Pays de la Loire Sleep Cohort were linked to health administrative data to identify proxies of heathy behaviors (HB) including adherence to cardiovascular (CV) drugs (medication possession ratio, [MPR]), cancer screening tests, influenza vaccination, alcohol and smoking consumption, and drowsiness-related road accidents during the two years preceding PAP onset in OSA patients. Multivariable regression analyses were conducted to evaluate the association of HB with subsequent PAP adherence. Healthcare resource use was evaluated according to subsequent PAP adherence. FindingsWe included 2,836 patients who had started PAP therapy between 2012 and 2018 (65% of whom were PAP adherent with mean daily use ≥4h/night). Being adherent to CV active drugs (MPR≥80%) and non-smoker were associated with a higher likelihood of PAP adherence (odds ratio, OR [95% confidence interval]: 1.43 [1.15; 1.77] and 1.37 [1.10; 1.71] respectively). Patients with no history of drowsiness-related road accidents were more likely to continue PAP (OR: 1.39 [1.04; 1.87]). PAP adherent patients used less healthcare resources 2 years before PAP initiation, than non-adherents (mean number of outpatient consultations: 19.0 vs 17.2, P=.003; hospitalization days: 5.7 vs 5.0, P=.04; emergency room visit: 30.7 vs 24.0% P=.0002). InterpretationPatients who adhere to PAP therapy of OSA were more health seeking and less healthcare users prior to device initiation than non-adherent patients. Until the HAE associated with PAP adherence is better understood, caution is warranted when interpreting the association of PAP adherence with CV health outcomes and healthcare resource use in non-randomized cohorts.

Circuit-dependent carbon dioxide rebreathing during continuous positive airway pressure

BackgroundThe current standard treatment for obstructive sleep apnea (OSA), continuous positive airway pressure (CPAP), is characterized by a low adherence rate due to various factors including circuit-dependent carbon dioxide (CO2) rebreathing, which can exacerbated by disparate factors, such as low PAP, use of auto-titrating PAP or ramps. However, risk factors for rebreathing are often overlooked or poorly understood in clinical practice. Therefore, our objective was to evaluate the extent of rebreathing occurring with commonly used CPAP masks across varying PAPs, tidal volumes, and respiratory rates. MethodsIn a bench study, we assessed the rebreathing rate of nine masks interfacing a CPAP with a lung simulator providing different breathing respiratory rates (15 or 20 breaths/min) and tidal volumes (400, 500, 600, 700 and 750 mL). Additionally, a theoretical model was developed to describe the likelihood of CO2 rebreathing from four different masks at various breathing settings. ResultsOverall, all masks performed worse in situations characterized by low PAPs, high tidal volumes, and high respiratory rates. However, Dreamwear, Nuance, Siesta, Vitera, and particularly V2 masks exhibited greater susceptibility to rebreathing compared to F20, P10, Brevida, and Rio masks for the same variations of PAPs or ventilatory parameters. The mathematical model suggested that the risk of rebreathing for Rio, P10 and Nuance mask is negligible for respiratory rates of 10 breaths/min or below. ConclusionsCircuit-dependent CO2 rebreathing can be a common occurrence and warrants careful mask selection upon CPAP therapy initiation for optimal clinical outcomes.

Effect of CPAP Treatment on Cardiovascular Outcomes

IntroductionRandomized controlled trials (RCT) have not demonstrated a role for continuous positive airway pressure (CPAP) on the secondary prevention of major cardiovascular events in obstructive sleep apnea (OSA) patients. However, participants in RCTs are substantially different from real-world patients. Therefore, we aimed to assess the effect of CPAP treatment on major cardiovascular events in real-world OSA patients. MethodsPopulation-based longitudinal observational study including all OSA patients with an active CPAP prescription at the beginning of 2011 in Catalonia, Spain, that terminated CPAP treatment during 2011 and did not have CPAP prescriptions between 2012-2015; and propensity-score-matched OSA patients that continued CPAP treatment until the end of 2015 or death. Adjusted hazard ratios were used to assess the association between CPAP treatment and overall and cardiovascular mortality, cardiovascular hospitalizations, or major adverse cardiovascular events (MACEs). Results3638 CPAP terminators and 10,914 propensity-score-matched continuators were included (median age 67 [57–77] years, 71.4% male). During a median follow-up of 47.9 months CPAP continuators showed a lower risk of cardiovascular death than terminators (hazard ratio [HR]: 0.61; 95% confidence interval [CI]: 0.50–0.75) after adjusting by age, sex and key comorbidities. Similar results were found for cardiovascular hospitalizations (HR: 0.87; 95% CI: 0.76–0.99) and MACEs (HR: 0.84; 95% CI: 0.75–0.95). ConclusionCPAP treatment continuation could be associated with a significantly lower risk of major cardiovascular events in real-world OSA patients. This result highlights the importance of including real-world patients in studies on OSA.

Impact of Continuous Positive Airway Pressure on Glucose Profiles in Gestational Diabetes: A Pilot Randomized-Controlled Trial.

Impact of Continuous Positive Airway Pressure on Glucose Profiles in Gestational Diabetes: A Pilot Randomized-Controlled Trial.

COVID-19 and mechanical ventilation

Mechanical ventilation (MV) is used to treat patients with severe coronavirus disease 2019 (COVID-19). This severe respiratory illness, typically develops 8 days after symptom onset and when it does not respond to non‐invasive respiratory support, it requires advanced respiratory support, including high concentrations of inspired oxygen and mechanical ventilation. Such therapies are also required for the acute respiratory distress syndrome (ARDS), which has been widely studied over several decade. Obesity as a disease causes a restrictive lung disease and is a sufficient predisposing factor for difficult ventilation. Higher BMI patients are more likely to be young, with single organ failure, less chronic comorbidity but with increased severity of hypoxemia at presentation. Severe respiratory failure from coronavirus disease 2019 pneumonia not responding to non‐invasive respiratory support requires mechanical ventilation. Although ventilation can be a life‐saving therapy, it can cause further lung injury if airway pressure and flow and their timing are not tailored to the respiratory system mechanics of the individual patient. The phenomenon of “hard lung” is observed as the ventilation of the intubated patient is very arduous and recruitment requires a lot of effort. Coronavirus disease 2019-induced acute respiratory distress syndrome is more severe in morbidly obese patients. This relationship between BMI and mortality was investigated by several observational studies, but the relationship was not universally observed. Some studies found increased BMI was associated with an increased risk of requiring intubation and ventilation, but with no clear relationship with mortality. The combination is quite difficult as these patients oppose the ventilator. Our objective was to determine the association between MV for treatment of COVID-19.

The different roles of homocysteine metabolism in hypertension among normal-weight and obese patients with obstructive sleep apnea

BackgroundObstructive sleep apnea (OSA) is associated with hypertension. However, the differential mechanisms underlying OSA-related hypertension between normal-weight vs. obese patients is limited. MethodsWe studied 92 patients with OSA and 24 patients with continuous positive airway pressure (CPAP) treatment. Blood pressure (BP) was measured twice during awake and continuously monitored during sleep. Obesity was defined as body mass index ≥28 kg/m2. Serum metabolite levels were assessed by metabolomics. ResultsAmong 59 normal-weight and 33 obese patients, 651 and 167 metabolites showed differences between hypertension and normotension or were associated with systolic and diastolic BP (SBP, DBP) after controlling confounders. These metabolites involved 16 and 12 Kyoto Encyclopedia of Genes and Genomes enrichment pathways in normal-weight and obese patients respectively, whereas 6 pathways overlapped. Among these 6 overlapping pathways, 4 were related to homocysteine metabolism and 2 were non-specific pathways. In homocysteine metabolism pathway, 13 metabolites were identified. Interestingly, the change trends of 7 metabolites associated with SBP (all interaction-p≤0.083) and 8 metabolites associated with DBP (all interaction-p≤0.033) were opposite between normal-weight and obese patients. Specifically, increased BP was associated with down-regulated folate-dependent remethylation and accelerated transsulfuration in normal-weight patients, whereas associated with enhanced betaine-dependent remethylation and reduced transsulfuration in obese patients. Similar findings were observed in ambulatory BP during sleep. After CPAP treatment, baseline low homocysteine levels predicted greater decrease in DBP among normal-weight but not obese patients. ConclusionsMechanisms in OSA-related hypertension differ between normal-weight and obese patients, which are explained by different changes in homocysteine metabolism.