The Mediator Role of Illness Representations in Patients with Obstructive Sleep Apnea: A Preliminary Study / [El papel mediador de las representaciones de la enfermedad en pacientes de apnea obstructiva del sueño: un estudio preliminar]

Background: This preliminary study examined the mediating role of illness representations on health-related quality of life (HRQoL) between adherent and poorly adherent obstructive sleep apnea patients (OSA) to the automatic positive airway pressure (APAP) therapy. Method: A total of 185 patients were assessed on determinants of APAP treatment, illness representations, family coping, and self-efficacy, at T1 (prior to APAP treatment) and T2 (1 to 2 months with APAP treatment). Results: Regarding the determinants of APAP, adherent patients showed higher self-efficacy, outcome expectations, and decisional balance index, compared to poorly adherent patients. Adherent patients also showed higher family coping and HRQoL, but less threatening cognitive representations compared to poorly adherent patients. Illness cognitive and emotional representations mediated the relationship between self-efficacy/family coping and HRQoL, in adherent patients. Only illness cognitive representations mediated the relationship between self-efficacy and HRQoL in poorly adherent patients. Conclusions: The results highlight the importance of illness representations during OSA treatment in the promotion of adherence to APAP.(AU)

Antecedentes: Este estudio preliminar examina el papel mediador de la representación de la enfermedad en la calidad de vida relacionada con la salud (CVRS) entre pacientes con apnea obstructiva del sueño (AOS) observantes y poco observantes de la terapia de presión positiva automática en las vías respiratorias (APAP). Método: Se evaluó a un total de 185 pacientes sobre los determinantes del tratamiento APAP, las representaciones de la enfermedad, el afrontamiento familiar y la autoeficacia en T1 (antes del tratamiento APAP) y T2 (1 a 2 meses con tratamiento APAP). Resultados: En cuanto a los determinantes de la APAP, los observantes mostraron mayor autoeficacia, expectativas de resultados e índice de equilibrio decisional en comparación con los poco observantes. Los observantes también mostraron un mayor afrontamiento familiar y CVRS pero menos representaciones cognitivas amenazantes en comparación con los observantes deficientes. Las representaciones cognitivas y emocionales de la enfermedad mediaron la relación entre la autoeficacia/afrontamiento familiar y la CVRS en pacientes observantes. Solo las representaciones cognitivas de enfermedad mediaron la relación entre la autoeficacia y la CVRS en pacientes de baja observancia. Conclusiones: Los resultados destacan la importancia de las representaciones de la enfermedad durante el tratamiento de la AOS en la promoción de la adherencia a la APAP.(AU)

Funciones ejecutivas en pacientes con apnea obstructiva del sueño: explorando el modelo prefrontal / Executive functions in patients with obstructive sleep apnea: exploring the prefrontal model

Introducción El modelo prefrontal propone que los individuos con apnea obstructiva del sueño (AOS) manifiestan conductas similares a un síndrome disejecutivo como resultado de las alteraciones de gases en la sangre y la fragmentación del sueño. Objetivo Comparar las funciones ejecutivas en pacientes con AOS con valores normativos y explorar su relación con las alteraciones de gases en la sangre y la fragmentación del sueño. Pacientes y métodos Se reclutó a pacientes de la comunidad general y de un hospital de tercer nivel. La puntuación obtenida en la evaluación neuropsicológica se contrastó con la t de Student para una muestra. Posteriormente, se estimó un análisis de regresión lineal múltiple mediante parámetros polisomnográficos de hipercapnia, hipoxemia y fragmentación del sueño como variables predictoras, y la puntuación de funciones ejecutivas como variable que se debe predecir. Resultados Pese a que el desempeño en la evaluación neuropsicológica del 26% de esta muestra se clasificó como alteración ejecutiva, los indicadores de fragmentación del sueño y alteraciones de gases no predijeron el desempeño ejecutivo. Conclusión Una fracción de los pacientes con AOS mostró un desempeño similar a un síndrome disejecutivo; no obstante, permanecen indefinidos los factores que subyacen y favorecen este tipo de manifestaciones cognitivas. La atención temprana de este problema de salud pública podría ser la mejor herramienta disponible en aras de mejorar la calidad de vida y prevenir riesgos a la salud. (AU)

INTRODUCTION According to the prefrontal model, individuals with obstructive sleep apnea (OSA) manifest behaviours mimicking dysexecutive syndrome as a result of blood gas abnormalities and sleep fragmentation. OBJECTIVE. To compare executive functions in OSA patients with normative values and explore their relationship with blood gas abnormalities and sleep fragmentation. PATIENTS AND METHODS Patients were recruited from the wider community and from a tertiary care hospital. The score obtained in the neuropsychological assessment was compared with Student’s t-test for a sample. A multiple linear regression analysis was subsequently estimated, using polysomnographic parameters of hypercapnia, hypoxemia and sleep fragmentation as the predictor variables, and the executive function score as the variable to be predicted. RESULTS Although the neuropsychological assessment performance of 26% of this sample was classified as executive impairment, indicators of sleep fragmentation and gas abnormalities failed to predict the performance of executive functions. CONCLUSION. A proportion of the patients with OSA presented performance similar to a dysexecutive syndrome; however, the factors underlying and fostering this type of cognitive manifestation remain unclear. Early treatment for this public health problem could be the best tool available for improving quality of life and preventing health risks. (AU)

Diabetes y apnea obstructiva del sueño. Un estudio de casos y controles / Diabetes and obstructive sleep apnoea: A case-control study

Introducción La apnea obstructiva del sueño (AOS) y la diabetes mellitus (DM) son enfermedades muy prevalentes frecuentemente asociadas. Su coexistencia se asocia de forma independiente con un aumento de la prevalencia de comorbilidades cardiovasculares. Al existir un infradiagnóstico de esta asociación, es necesario optimizar la sospecha clínica mediante el estudio de predictores independientes de DM o de prediabetes (preDM) en pacientes con AOS. Método Estudio de casos y controles, seleccionados de manera aleatoria simple y emparejados por sexo, índice de masa corporal (IMC) y edad, que pretende estudiar la asociación de la AOS con la DM y la preDM e identificar factores predictores independientes para ambas enfermedades, en las personas con AOS. Resultados Incluimos 208 casos con AOS y 208 controles, sin AOS. En los primeros, el 18,8% tenían DM, por solo el 10,1% en los segundos (p=0,00). La prevalencia de preDM fue del 41,8% vs el 10,6%, respectivamente (p=0,00). Ciento veinticuatro casos (59,6%) refirieron excesiva somnolencia diurna (ESD) (escala Epworth, 10,5±3,1) vs el 24,5% del grupo control (escala Epworth, 6,6±2,9). El índice de apnea-hipopnea (IAH) y los índices de desaturación de O2 (IDO, CT90 y CT80) fueron significativamente mayores en el grupo de casos. El riesgo de presentar DM se relacionó con la edad, la hipoxemia nocturna y la ESD. El riesgo de presentar preDM, con el IMC y con el IAH. Conclusiones La AOS se asocia a la DM y a la preDM. La edad, la hipoxemia nocturna y la ESD son predictores de DM. El IMC y el IAH lo son de la preDM. (AU)

Introduction Obstructive sleep apnoea (OSA) and diabetes mellitus (DM) are very prevalent diseases frequently associated. Their coexistence is independently associated with an increased prevalence of cardiovascular comorbidities. As this association is underdiagnosed, it is necessary to optimise clinical suspicion by studying independent predictors of DM or prediabetes (preDM) in patients with OSA. Method A simple randomised case-control study, matched for sex, body mass index (BMI) and age, aimed to study the association of OSA with DM and preDM and to identify independent predictors for both diseases in people with OSA. Results We included 208 cases with OSA and 208 controls without OSA. In the former, 18.8% had DM compared to only 10.1% in the latter (P=.00). Prevalence of preDM was 41.8% vs. 10.6%, respectively (P=.00). One hundred and twenty-four cases (59.6%) reported excessive daytime sleepiness (EDS) (Epworth scale, 10.5±3.1) vs. 24.5% of the control group (Epworth scale, 6.6±2.9). Apnoea-hypopnoea index (AHI) and O2 desaturation indices (IDO, CT90 and CT80) were significantly higher in the case group. The risk of MD was related to age, nocturnal hypoxaemia and EDS. The risk of pre-MD was related to BMI and AHI. Conclusions OSA is associated with DM and preDM. Age, nocturnal hypoxaemia and EDS are predictors of DM. BMI and AHI are predictors of pre-MD. (AU)

Diabetes y apnea obstructiva del sueño. Un estudio de casos y controles / Diabetes and obstructive sleep apnoea: A case-control study

Introducción La apnea obstructiva del sueño (AOS) y la diabetes mellitus (DM) son enfermedades muy prevalentes frecuentemente asociadas. Su coexistencia se asocia de forma independiente con un aumento de la prevalencia de comorbilidades cardiovasculares. Al existir un infradiagnóstico de esta asociación, es necesario optimizar la sospecha clínica mediante el estudio de predictores independientes de DM o de prediabetes (preDM) en pacientes con AOS. Método Estudio de casos y controles, seleccionados de manera aleatoria simple y emparejados por sexo, índice de masa corporal (IMC) y edad, que pretende estudiar la asociación de la AOS con la DM y la preDM e identificar factores predictores independientes para ambas enfermedades, en las personas con AOS. Resultados Incluimos 208 casos con AOS y 208 controles, sin AOS. En los primeros, el 18,8% tenían DM, por solo el 10,1% en los segundos (p=0,00). La prevalencia de preDM fue del 41,8% vs el 10,6%, respectivamente (p=0,00). Ciento veinticuatro casos (59,6%) refirieron excesiva somnolencia diurna (ESD) (escala Epworth, 10,5±3,1) vs el 24,5% del grupo control (escala Epworth, 6,6±2,9). El índice de apnea-hipopnea (IAH) y los índices de desaturación de O2 (IDO, CT90 y CT80) fueron significativamente mayores en el grupo de casos. El riesgo de presentar DM se relacionó con la edad, la hipoxemia nocturna y la ESD. El riesgo de presentar preDM, con el IMC y con el IAH. Conclusiones La AOS se asocia a la DM y a la preDM. La edad, la hipoxemia nocturna y la ESD son predictores de DM. El IMC y el IAH lo son de la preDM. (AU)

Introduction Obstructive sleep apnoea (OSA) and diabetes mellitus (DM) are very prevalent diseases frequently associated. Their coexistence is independently associated with an increased prevalence of cardiovascular comorbidities. As this association is underdiagnosed, it is necessary to optimise clinical suspicion by studying independent predictors of DM or prediabetes (preDM) in patients with OSA. Method A simple randomised case-control study, matched for sex, body mass index (BMI) and age, aimed to study the association of OSA with DM and preDM and to identify independent predictors for both diseases in people with OSA. Results We included 208 cases with OSA and 208 controls without OSA. In the former, 18.8% had DM compared to only 10.1% in the latter (P=.00). Prevalence of preDM was 41.8% vs. 10.6%, respectively (P=.00). One hundred and twenty-four cases (59.6%) reported excessive daytime sleepiness (EDS) (Epworth scale, 10.5±3.1) vs. 24.5% of the control group (Epworth scale, 6.6±2.9). Apnoea-hypopnoea index (AHI) and O2 desaturation indices (IDO, CT90 and CT80) were significantly higher in the case group. The risk of MD was related to age, nocturnal hypoxaemia and EDS. The risk of pre-MD was related to BMI and AHI. Conclusions OSA is associated with DM and preDM. Age, nocturnal hypoxaemia and EDS are predictors of DM. BMI and AHI are predictors of pre-MD. (AU)

Chronic Respiratory Diseases as a Risk Factor for Herpes Zoster Infection

Introduction: Herpes zoster (HZ) is a condition that results from the reactivation of the varicella zoster virus (VZV). Several diseases have been reported to increase the risk of developing HZ and postherpetic neuralgia (PHN). The objective of this study is to analyze the prevalence and risk factors for HZ and PHN in the most frequent chronic respiratory diseases, which are chronic obstructive pulmonary disease (COPD), asthma, lung cancer and obstructive sleep apnea (OSA). Methods: We conducted an observational, retrospective, non-interventional study between January 2012 and December 2020 based on data from the Castilla-La Mancha Regional Health System in Spain. We used the Savana Manager 3.0 artificial intelligence-enabled system to collect information from electronic medical records. Results: 31765 subjects presented a diagnosis of HZ. Mean age was 64.5 years (95%CI 64.3–64.7), and 58.2% were women. The prevalence of HZ showed an increasing trend in patients over the age of 50. A risk analysis adjusted for sex and comorbidities in COPD, asthma, lung cancer and OSA presented a higher risk of developing HZ in the first three (OR 1.16 [95%CI 1.13–1.19], 1.67 [1.63–1.71], 1.68 [1.60–1.76], respectively), which further increased in all three when associated with comorbidities. Regarding postherpetic neuralgia, an increased risk was only observed related to COPD and lung cancer (OR 1.24 [95%CI 1.23–1.25], 1.14 [1.13–1.16], respectively), further increasing when associated with comorbidities. Conclusions: In a standard clinical practice setting, the most prevalent respiratory diseases (asthma, COPD and lung cancer) are related to a higher risk of HZ and PHN. These data are fundamental to assess the potential impact of vaccination in this population. (AU)

Recovery Mimicking “Ideal” CPAP Adherence Does Not Improve Wakefulness or Cognition in Chronic Murine Models of OSA: Effect of Wake-Promoting Agents

Introduction: Obstructive sleep apnea (OSA) is a chronic condition characterized by intermittent hypoxia (IH) and sleep fragmentation (SF). OSA can induce excessive daytime sleepiness (EDS) and is associated with impaired cognition and anxiety. Solriamfetol (SOL) and modafinil (MOD) are widely used wake-promoting agents in OSA patients with EDS. Methods: Male C57Bl/6J mice were exposed to SF along with sleep controls (SC) or to IH and room air (RA) controls during the light (inactive) phase for 4 and 16 weeks, respectively. Both IH and SF exposures were then discontinued to mimic “ideal” continuous positive airway pressure (CPAP) adherence. All groups were then randomly assigned to receive once daily intraperitoneal injections of SOL, MOD, or vehicle (VEH) for 6 days. Sleep/wake activity was assessed along with tests of explicit memory, anxiety and depression were performed before and after treatments. Results: IH and SF exposures increased sleep percentage in the dark phase and reduced wake bouts lengths (i.e., EDS), and induced cognitive deficits and impulsivity in mice. Both SOL and MOD treatments effectively mitigated EDS when combined with recovery, while recovery alone did not improve EDS over the 6-day period. Furthermore, improvements explicit memory emerged only after SOL. Conclusion: Chronic IH and SF induce EDS in young adult mice that is not ameliorated by recovery except when combined with either SOL or MOD. SOL, but not MOD, significantly improves IH-induced cognitive deficits. Thus, SOL emerges as a viable adjuvant medication for residual EDS in OSA along with its positive impact on cognition. (AU)

«Duermo todo el día para demostrarle al mundo que lucho por mis sueños» / “I sleep all day to show the world that I fight for my dreams”

Se presenta el caso clínico de un paciente que asocia tres trastornos de sueño diferentes: narcolepsia, apnea obstructiva del sueño (AOS) y trastorno de conducta del sueño REM. El objetivo es resaltar la importancia de la narcolepsia, una patología infradiagnosticada y que a veces puede quedar enmascarada por otros trastornos de sueño. En este caso, el paciente es diagnosticado inicialmente de AOS, pero dado que persiste con hipersomnolencia diurna debemos descartar otras causas. (AU)

We report a clinical case of a patient who presents three different sleep disorders, namely, narcolepsy, obstructive sleep apnea (OSA), and REM sleep behavior disorder. The objective of this study is to highlight the importance of narcolepsy, which is an underdiagnosed pathology that can sometimes be masked by other sleep disorders. In this case, the patient is initially diagnosed with OSA, but, due to the persistence of excessive daytime sleepiness, we have to rule out other causes. (AU)

Soporte telemático de autogestión para pacientes con apnea obstructiva del sueño en tratamiento con CPAP: aspectos metodológicos y resultados preliminares del ensayo clinico telesas / Telematic self-management support for patients with obstructive sleep apnea under CPAP treatment: methodological aspects and preliminary results of the telesas clinical trial

Objetivo: Comprobar si un programa de telemedicina mejora el cumplimiento con CPAP, alcanzando un uso de, al menos, 4 horas al día en el 90% de los pacientes. Realizamos un estudio piloto para comprobar la viabilidad de un proyecto multicéntrico en el que perfeccionaremos dicho programa. Metodología: Pacientes con AOS severa poco sintomáticos en tratamiento con CPAP fueron randomizados a seguimiento habitual o seguimiento habitual más un programa de telemedicina durante 6 meses. Dentro de este programa, las variables de telemonitorización, la aparición de efectos secundarios y la presencia de sueño reparador eran analizadas para generar alarmas e instrucciones al paciente para la autogestión precoz de los problemas presentados con la CPAP. Resultados: 60 pacientes fueron randomizados, 33 al grupo intervención y 27 al grupo control, sin diferencias significativas en las variables basales. El 80% eran hombres con un rango de edad entre los 24 y 75 años. Solo hubo un abandono en el grupo control. Conclusiones: El uso de nuestro programa de telemedicina no ha supuesto ningún problema para los pacientes incluidos a pesar de la horquilla amplia de edad, siendo viable el desarrollo de un estudio a mayor escala con una herramienta de telemedicina perfeccionada. (AU)

Basis: poor compliance with CPAP is a problem at a clinical and research level, assuming the expected results are not achieved. The benefits of using telemedicine in obstructive sleep apnea (OSA) are inconclusive, with its positive effect on compliance being the most consistent in the literature. Objective: to check if a telemedicine program improves compliance with CPAP, reaching use of at least 4 hours a day in 90% of patients. We carried out a pilot study to verify the viability of a multicenter project in which we will perfect this program. Method: patients with severe OSA with few symptoms on CPAP treatment were randomized to usual follow-up or usual follow-up plus a telemedicine program for 6 months. Within this program, the telemonitoring variables, the appearance of side effects and the presence of restorative sleep were analyzed to generate alarms and instructions to the patient for early self-management of the problems presented with CPAP. Preliminary results: 60 patients were randomized, 33 to the intervention group and 27 to the control group, with no significant differences in the baseline variables. 80% were men with an age range between 24 and 75 years. There was only one dropout in the control group. Conclusions: the use of our telemedicine program has not posed any problems for the included patients despite the wide age range, making it feasible to develop a larger-scale study with an improved telemedicine tool. (AU)

Upper airway assessment in obstructive sleep apnea patients: can computed tomography with lateral cephalometry replace drug-induced sleep endoscopy (DISE)? / Evaluación de la vía aérea superior en pacientes con apnea obstructiva del sueño: ¿puede la tomografía computarizada con cefalometría lateral reemplazar endoscopia del sueño inducida por fármacos por fármacos?

Objective To evaluate the association between results from drug-induced sleep endoscopy (DISE) and computed tomography with lateral cephalometry (CTLC) of the pharynx in obstructive sleep apnea (OSA) patients, regarding the same anatomic level, in order to understand if CTLC could replace DISE in selected patients. Study design Cross-sectional. Setting Tertiary hospital. Methods A total of 71 patients who attended the Sleep Medicine Consultation in the Otorhinolaryngology Department of Hospital CUF Tejo between 1.6.2019 and 30.9.2021, performed a polysomnographic sleep study and were elected to undergo DISE and CTLC of the pharynx for diagnostic purposes were selected. Obstructions at the same anatomic levels – tongue base, epiglottis and velum - were compared in both exams. Results Patients with reduction of epiglottis-pharynx space on CTLC had also a complete obstruction at epiglottis level on the VOTE classification of DISE (p = 0,027). Reduction of velum-pharynx space or tongue base-pharynx space were not related to complete obstruction of the velum (P = 0,623) or the tongue base (p = 0,594) found in DISE. Those with two or more space reductions had a tendency to multilevel obstruction observed in DISE (p = 0.089). Conclusion When evaluating the obstruction level(s) of an OSA patient, efforts should be made to perform DISE, since CTLC measures, though regarding at the same structures, don´t correlate completely with obstructions observed in DISE. (AU)

Objetivo Evaluar la asociación entre los resultados de la endoscopia del sueño inducida por fármacos (DISE) y la tomografía computarizada con cefalometría lateral (TCCL) de faringe en pacientes con apnea obstructiva del sueño (AOS), en el mismo nivel anatómico, para comprender si la TCCL podría reemplazar DISE en pacientes seleccionados. Diseño del estudio Transversal. Lugar Hospital de tercer nivel. Métodos Un total de 71 pacientes que acudieron a la Consulta de Medicina del Sueño en el Servicio de Otorrinolaringología del Hospital CUF Tejo entre el 1.6.2019 y el 30.9.2021, a los que se les había realizado un estudio polisomnográfico del sueño y fueron elegidos para realizar DISE y TCCL de faringe con fines diagnósticos, fueron seleccionados. Las obstrucciones en los mismos niveles anatómicos (base de la lengua, epiglotis y velo) se compararon en ambos exámenes. Resultados Los pacientes con reducción del espacio epiglotis-faringe en TCCL también tenían una obstrucción completa a nivel de epiglotis en la clasificación VOTE de DISE (p = 0,027). La reducción del espacio velo-faringe o base de la lengua-faringe no se relacionó con la obstrucción completa del velo (P = 0,623) o de la base de la lengua (p = 0,594) encontrada en DISE. Aquellos con dos o más reducciones de espacio presentaron tendencia a la obstrucción multinivel observada en DISE (p = 0,089). Conclusión Al evaluar el o los niveles de obstrucción de un paciente con AOS, se debe intentar realizar DISE, ya que las medidas de TCCL, aunque se refieren a las mismas estructuras, no se correlacionan completamente con las obstrucciones observadas en DISE. (AU)

Intermittent Hypoxia Mediates Cancer Development and Progression Through HIF-1 and miRNA Regulation

Introduction: There is still a debate for the link between obstructive sleep apnoea (OSA) and cancer. The mechanisms underlying this causality are poorly understood. Several miRNAs are involved in cancer development and progression with expression being influenced by hypoxia. The aims of this work were (i) to compare miRNAs expression in controls versus patients affected by OSA without or with cancer (ONCO-OSA) and (ii) in colorectal cancer cells exposed to intermittent hypoxia (IH), to evaluate miRNAs impact on tumor progression in vitro. Methods: We detected miRNAs by qRT-PCR in patients’ sera and in CaCo2 cells exposed to 2–32h of IH with or without acriflavine (ACF), a HIF-1 inhibitor. Viability and transwell invasion test were applied to investigate the proliferation and migration of CaCo2 exposed to IH and treated with miRNA inhibitors or acriflavine. HIF-1α activity was evaluated in CaCo2 cells after IH. Results: The levels of miR-21, miR-26a and miR-210 increased in OSA and ONCO-OSA patients compared to controls. MiR-23b increased in ONCO-OSA patients, and miR-27b and miR-145 increased in OSA but not ONCO-OSA patients. MiR-21, miR-26a, miR-23b and miR-210 increased in cells after IH. IH stimulated cell proliferation and migration. This effect was reduced after either miRNA inhibition or acriflavine treatment. MiRNA inhibition reduces HIF-1α gene expression. Conversely, acriflavine reduced the expression of these miRNAs. Conclusions: We identified a signature of miRNAs, induced by the IH environment. They could be implicated in cancer development and progression through a regulatory loop involving HIF-1. (AU)

Polysomnographic Phenotypes of Obstructive Sleep Apnea in a Real-Life Cohort: A Pathophysiological Approach

Introduction: Obstructive sleep apnea (OSA) is heterogeneous and complex, but its severity is still based on the apnea–hypoapnea index (AHI). The present study explores using cluster analysis (CA), the additional information provided from routine polysomnography (PSG) to optimize OSA categorization. Methods: Cross-sectional study of OSA subjects diagnosed by PSG in a tertiary hospital sleep unit during 2016–2020. PSG, demographical, clinical variables, and comorbidities were recorded. Phenotypes were constructed from PSG variables using CA. Results are shown as median (interquartile range). Results: 981 subjects were studied: 41% females, age 56 years (45–66), overall AHI 23events/h (13–42) and body mass index (BMI) 30kg/m2 (27–34). Three PSG clusters were identified: Cluster 1: “Supine and obstructive apnea predominance” (433 patients, 44%). Cluster 2: “Central, REM and shorter-hypopnea predominance” (374 patients, 38%). Cluster 3: “Severe hypoxemic burden and higher wake after sleep onset” (174 patients, 18%). Based on classical OSA severity classification, subjects are distributed among the PSG clusters as severe OSA patients (AHI≥30events/h): 46% in cluster 1, 17% in cluster 2 and 36% in cluster 3; moderate OSA (15≤AHI<30events/h): 57% in cluster 1, 34% in cluster 2 and 9% in cluster 3; mild OSA (5≤AHI<15events/h): 28% in cluster 1, 68% in cluster 2 and 4% in cluster 3. Conclusions: The CA identifies three specific PSG phenotypes that do not completely agree with classical OSA severity classification. This emphasized that using a simplistic AHI approach, the OSA severity is assessed by an incorrect or incomplete analysis of the heterogeneity of the disorder. (AU)

Effect of Continuous Positive Airway Pressure on Glucose and Lipid Profiles in Patients With Obstructive Sleep Apnoea: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background and aim: Continuous Positive Airway Pressure (CPAP) is the most effective therapy for symptomatic obstructive sleep apnoea (OSA). However, uncertainty remains about the effectiveness of CPAP in improving OSA-related metabolic dysregulation. This meta-analysis of randomized controlled trials (RCTs) aimed to investigate whether CPAP, compared to other control treatments, could improve glucose or lipid metabolism in OSA patients. Methods: Relevant articles were searched in three different databases (MEDLINE, EMBASE and Web of Science) from inception to 6th Feb 2022 through specific search terms and selection criteria. Results: From a total of 5553 articles, 31 RCTs were included. CPAP modestly improved insulin sensitivity as determined by mean fasting plasma insulin and Homeostasis Model Assessment of Insulin Resistance reduction of 1.33mU/L and 0.287, respectively. In subgroup analyses pre-diabetic/type 2 diabetic patients as well as those with sleepy OSA showed a greater response to CPAP. Regarding lipid metabolism, CPAP was associated with a mean total cholesterol reduction of 0.064mmol/L. In subgroup analyses, the benefit was higher in patients that showed more severe OSA and oxygen desaturations at the baseline sleep study as well as in younger and obese subjects. Neither glycated haemoglobin nor triglycerides, HDL- and LDL-cholesterol were reduced by CPAP. Conclusion: CPAP treatment may improve insulin sensitivity and total cholesterol levels in OSA patients but with low effect size. Our results suggest that CPAP does not substantially improve metabolic derangements in an unselected OSA population, but the effect may be higher in specific subgroups of OSA patients. (AU)