Depression and comorbid obstructive sleep apnea: Association between positive airway pressure adherence, occurrence of self-harm events, healthcare resource utilization, and costs.

OBJECTIVE: Previous studies have shown that treatment of obstructive sleep apnea (OSA) with positive airway pressure (PAP) therapy in patients with depression may improve depression symptoms and response to antidepressant therapy. We investigated the association between PAP therapy adherence, self-harm events, healthcare resource utilization (HCRU), and costs over 2 years in a national sample of patients with pre-existing depression and newly diagnosed comorbid OSA. METHODS: Administrative claims data were linked to objective PAP therapy usage. Inverse probability treatment weighting was used to compare outcomes over 2 years across PAP adherence levels. The predicted numbers of emergency room (ER) visits and hospitalizations by adherence level were assessed using risk-adjusted generalized linear models. RESULTS: 37,459 patients were included. Relative to non-adherent patients, consistently adherent patients had fewer self-harm events (0.04 vs 0.05, p < 0.001) after 1 year, and significantly (all p < 0.001) fewer ER visits (0.66 vs 0.86) and all-cause hospitalizations (0.13 vs 0.17), and lower total ($11,847 vs $11,955), inpatient hospitalization ($1634 vs $2274), and ER visit ($760 vs $1006) costs per patient in the second year of PAP therapy. Consistently adherent patients showed lower risk for hospitalizations and ER visits. LIMITATIONS: Using observational claims data, we were unable to assess clinical characteristics including sleep, sleepiness, and daytime symptoms, or important social determinants of health. We were limited in assessing care received outside of the included health plans. CONCLUSION: Consistent adherence to PAP therapy over 2 years was associated with improved HCRU outcomes for patients with pre-existing depression newly diagnosed with comorbid OSA.

The multifaceted aspects of sleep and sleep-wake disorders following stroke.

Sleep-wake disorders (SWD) are acknowledged risk factors for both ischemic stroke and poor cardiovascular and functional outcome after stroke. SWD are frequent following stroke, with sleep apnea (SA) being the most frequent SWD affecting more than half of stroke survivors. While sleep disturbances and SWD are frequently reported in the acute phase, they may persist in the chronic phase after an ischemic stroke. Despite the frequency and risk associated with SWD following stroke, screening for SWD remains rare in the clinical setting, due to challenges in the assessment of post-stroke SWD, uncertainty regarding the optimal timing for their diagnosis, and a lack of clear treatment guidelines (i.e., when to treat and the optimal treatment strategy). However, little evidence support the feasibility of SWD treatment even in the acute phase of stroke and its favorable effect on long-term cardiovascular and functional outcomes. Thus, sleep health recommendations and SWD treatment should be systematically embedded in secondary stroke prevention strategy. We therefore propose that the management of SWD associated with stroke should rely on a multidisciplinary approach, with an integrated diagnostic, treatment, and follow-up strategy. The challenges in the field are to improve post-stroke SWD diagnosis, prognosis and treatment, through a better appraisal of their pathophysiology and temporal evolution.

Non-invasive ventilation in neuromuscular diseases: should we use higher levels of ventilatory support?

PURPOSE: In patients with COPD, one of the leading indications for domiciliary non-invasive ventilation (NIV), a major paradigm shift has been observed over the past decade in the method for adjusting NIV settings, with the use of sufficient ventilatory support to achieve a significant reduction in PaCO2. Whether this approach may be relevant to other populations, especially slowly progressive neuromuscular diseases (NMD), is unknown. METHODS: This study was conducted as a post hoc analysis from a previously published randomized controlled trial (NCT03458507). Patients with NMD treated with domiciliary NIV were stratified according to the level of ventilatory support: high-level tidal volume (HLVT; mL/kg of predicted body weight [PBW]) or high-level pressure support (HLPS), defined as a value above median value of the whole population (> 6.8 mL/kgPBW or 9.0 cmH2O, respectively). Primary outcome was mean nocturnal transcutaneous CO2 pressure (PtcCO2). Secondary outcomes included adherence to NIV, leaks, and side effects. RESULTS: Of a total of 26 patients, 13 were exposed to HLVT, with significantly lower nocturnal PtcCO2 (respectively 40.5 ± 4.2 vs. 46.3 ± 3.9 mmHg, p = 0.002). A linear correlation between VT (mL/kgPBW) and mean nocturnal PtcCO2 was evidenced (r = - 0.59, 95%CI [- 0.80; - 0.25], p = 0.002). No significant impact of HLVT was found on secondary outcomes. CONCLUSION: Despite the lack of power of this post hoc analysis, our results suggest that higher levels of ventilatory support are correlated with lower PtcCO2 in patients with NMD. Further studies are desirable to assess the extent to which the level of assistance influences PaCO2 evolution in patients with slowly progressive NMD, as well as in restrictive thoracic disorders.

[The roles of patients in healthcare provision, training and research: A French perspective]. / Rôles des patients dans le système de santé, la formation et la recherche en santé : une perspective française.

In 2002, patients were transformed into users of the French health system. As this opinion piece demonstrates, in 2021 they may at least potentially participate more actively than before. They can convey their knowledge of a disease and its treatments, and voluntarily share their experience. They can intervene in user representation and therapeutic patient education, the objective being to increase the autonomy of one and all, patients and public, in the training of professionals, clinical research and evolution of the health system. The rationale for the involvement of patients and their roles in provision of care, training and clinical research are analyzed from a French perspective. The obstacles to overcome and improvements to be achieved are reviewed, the objective being to promote enhanced health democracy through increased patient engagement. In 2021, however, the role of patients in the design and implementation of therapeutic patient education (TPE) and in the development of medical studies curricula remains limited if not restricted; this is due not only to a lack of information, but also to the resistance of health professionals and universities. Patients could and should assume a major role, fostering evolution toward a more just and effective health care system.

[Sleep characteristics of a population of patients seeking bariatric surgery]. / Caractéristiques du sommeil dans une population de patients candidats à une chirurgie bariatrique.

INTRODUCTION: Investigation for obstructive sleep apnea syndrome (OSAS) is mandatory before bariatric surgery. Data regarding chronic insomnia and chronic sleep deprivation are scarce in this population. METHODS: A cross-sectional study assessing the prevalence of chronic insomnia, OSAS and chronic sleep privation in an obese population referred for bariatric surgery. RESULTS: In all, 88 patients (74% women, median age 41 [33.5-50] years and median body mass index 42 [39.2-45.7] kg/m2) were included. The prevalence of chronic insomnia was 31% in the 87% suffering from OSAS that required continuous positive airway pressure therapy. Comorbid insomnia and sleep apnoea (COMISA) were found in 27% of our population. Chronic insomnia was associated with a lower quality of life (median EQ5D analogue visual scale: 60 [50-70] P=0.04) and a poor sleep quality (median Pittsburgh sleep quality index (PSQI): 8 (6-11 P<0.01) The deleterious combination of sleep privation and insomnia had a higher impact in terms of impairment of quality of life and sleep quality (median EQ5D analogue visual scale: 50 [40-65] P=0.02 et median PSQI: 11 [9-14, P<0.01) CONCLUSION: Chronic insomnia and sleep privation have synergistic deleterious effects in candidates for bariatric surgery. Further studies need to be conducted to evaluate the evolution after surgery.

Effectiveness of pulmonary rehabilitation in COVID-19 respiratory failure patients post-ICU.

INTRODUCTION: Some COVID-19 patients develop respiratory failure requiring admission to intensive care unit (ICU). We aim to evaluate the effects of pulmonary rehabilitation (PR) post-ICU in COVID-19 patients. METHODS: Twenty-one COVID-19 patients were evaluated pre- and post-PR and compared retrospectively to a non-COVID-19 group of 21 patients rehabilitated after ICU admission due to respiratory failure. RESULTS: PR induced greater 6-min walking distance improvement in COVID-19 patients (+205 ± 121 m) than in other respiratory failure patients post-ICU (+93 ± 66 m). The sooner PR was performed post-ICU, the better patients recovered. CONCLUSIONS: PR induced large functional improvements in COVID-19 patients post-ICU although significant physical and psychosocial impairments remained post-PR.

Self-reported sleepiness and not the apnoea hypopnoea index is the best predictor of sleepiness-related accidents in obstructive sleep apnoea.

To evaluate the value of apnoea + hypopnoea index versus self-reported sleepiness at the wheel in anticipating the risk of sleepiness-related accidents in patients referred for obstructive sleep apnoea. A cross-sectional analysis of the French national obstructive sleep apnoea registry. 58,815 subjects referred for a suspicion of obstructive sleep apnoea were investigated by specific items addressing sleepiness at the wheel and sleepiness-related accidents. Apnoea + hypopnoea index was evaluated with a respiratory polygraphy or full polysomnography. Subjects had a median age of 55.6 years [45.3; 64.6], 65% were men, with a median apnoea + hypopnoea index of 22 [8; 39] events/h. Median Epworth sleepiness scale score was 9 [6; 13], 35% of the patients reported sleepiness at the wheel (n = 20,310), 8% (n = 4,588) reported a near-miss accident and 2% (n = 1,313) reported a sleepiness-related accident. Patients reporting sleepiness at the wheel whatever their obstructive sleep apnoea status and severity exhibited a tenfold higher risk of sleepiness-related accidents. In multivariate analysis, other predictors for sleepiness-related accidents were: male gender, ESS, history of previous near-miss accidents, restless leg syndrome/periodic leg movements, complaints of memory dysfunction and nocturnal sweating. Sleep apnoea per se was not an independent contributor. Self-reported sleepiness at the wheel is a better predictor of sleepiness-related traffic accidents than apnoea + hypopnoea index.

[Factors associated with the type of mask used during nocturnal NIV in patients with neuromuscular disorders]. / Facteurs associés au masque de ventilation non invasive nocturne chez les patients neuromusculaires adultes.

In subjects with neuromuscular diseases (NMD), the choice of facemask is essential for successful long-term noninvasive ventilation (NIV). While nasal masks usually represent the first line of treatment, almost a third of our subjects with NMD use an oro-nasal interface. Factors associated with the choice of mask remain poorly understood. We provide an original analysis of a previous prospective, multi-centric, Franco-Belgian survey investigating the factors associated with the type of nocturnal mask used in 116 adult NMD subjects treated with NIV. In these patients oro-nasal mask use was more often associated with non-Duchenne muscular dystrophy, older subjects, higher body mass index, better upper limb autonomy allowing independent mask removal and shorter periods of ventilation. Controlled prospective studies are needed to compare the efficacy and tolerance of different interfaces in this specific population.

[Cardiac dysfunction and the obstructive sleep apnoea syndrome]. / Dysfonction cardiaque et syndrome d'apnée du sommeil.

INTRODUCTION: Cardiac insufficiency affects nearly 2% of the population with increased morbidity/mortality despite advances in therapeutic management. The sleep apnoea syndrome (SAS) is a risk factor for, and cause of aggravation of, myocardial dysfunction. BACKGROUND: SAS is found in 70% of patients with chronic cardiac failure, 65% of patients with refractory hypertension, 60% of patients with cerebro-vascular accidents and 50% of patients with atrial fibrillation. The associated cardiovascular mortality is multiplied by a factor of 2 to 3. The pathophysiological mechanisms are intermittent nocturnal hypoxia, variations in CO2 levels, variations in intrathoracic pressure and repeated arrousals from sleep, concurrent with sympathetic hyperactivity, endothelial dysfunction and systemic inflammation. CONCLUSIONS: SAS and cardiological management in patients presenting with myocardial dysfunction should be combined. It is necessary to pursue the scientific investigations with the aim of determining a precise care pathway and the respective places of each of the cardiological and pulmonary measures.

European Respiratory Society guidelines on long-term home non-invasive ventilation for management of COPD

While the role of acute non-invasive ventilation (NIV) has been shown to improve outcome in acute life-threatening hypercapnic respiratory failure in COPD, the evidence of clinical efficacy of long-term home NIV (LTH-NIV) for management of COPD is less. This document provides evidence-based recommendations for the clinical application of LTH-NIV in chronic hypercapnic COPD patients. The European Respiratory Society task force committee was composed of clinicians, methodologists and experts in the field of LTH-NIV. The committee developed recommendations based on the GRADE (Grading, Recommendation, Assessment, Development and Evaluation) methodology. The GRADE Evidence to Decision framework was used to formulate recommendations. A number of topics were addressed under a narrative format which provides a useful context for clinicians and patients. The task force committee delivered conditional recommendations for four actionable PICO (target population-intervention-comparator-outcome) questions, 1) suggesting for the use of LTH-NIV in stable hypercapnic COPD; 2) suggesting for the use of LTH-NIV in COPD patients following a COPD exacerbation requiring acute NIV 3) suggesting for the use of NIV settings targeting a reduction in carbon dioxide and 4) suggesting for using fixed pressure support as first choice ventilator mode. Managing hypercapnia may be an important intervention for improving the health outcome of COPD patients with chronic respiratory failure. The task force conditionally supports the application of LTH-NIV to improve health outcome by targeting a reduction in carbon dioxide in COPD patients with persistent hypercapnic respiratory failure. These recommendations should be applied in clinical practice by practitioners that routinely care for chronic hypercapnic COPD patients.

Hyperlipidaemia prevalence and cholesterol control in obstructive sleep apnoea: Data from the European sleep apnea database (ESADA).

BACKGROUND AND OBJECTIVE: Obstructive sleep apnoea (OSA) and hyperlipidaemia are independent risk factors for cardiovascular disease. This study investigates the association between OSA and prevalence of hyperlipidaemia in patients of the European Sleep Apnea Database (ESADA) cohort. METHODS: The cross-sectional analysis included 11 892 patients (age 51.9 ± 12.5 years, 70% male, body mass index (BMI) 31.3 ± 6.6 kg/m2 , mean oxygen desaturation index (ODI) 23.7 ± 25.5 events/h) investigated for OSA. The independent odds ratio (OR) for hyperlipidaemia in relation to measures of OSA (ODI, apnoea-hypopnoea index, mean and lowest oxygen saturation) was determined by means of general linear model analysis with adjustment for important confounders such as age, BMI, comorbidities and study site. RESULTS: Hyperlipidaemia prevalence increased from 15.1% in subjects without OSA to 26.1% in those with severe OSA, P < 0.001. Corresponding numbers in patients with diabetes were 8.5% and 41.5%, P < 0.001. Compared with ODI quartile I, patients in ODI quartiles II-IV had an adjusted OR (95% CI) of 1.33 (1.15-1.55), 1.37 (1.17-1.61) and 1.33 (1.12-1.58) (P < 0.001), respectively, for hyperlipidaemia. Obesity was defined as a significant risk factor for hyperlipidaemia. Subgroups of OSA patients with cardio-metabolic comorbidities demonstrated higher prevalence of HL. In addition, differences in hyperlipidaemia prevalence were reported in European geographical regions with the highest prevalence in Central Europe. CONCLUSION: Obstructive sleep apnoea, in particular intermittent hypoxia, was independently associated with the prevalence of hyperlipidaemia diagnosis.

Guidance to 2018 good practice: ARIA digitally-enabled, integrated, person-centred care for rhinitis and asthma.

AIMS: Mobile Airways Sentinel NetworK (MASK) belongs to the Fondation Partenariale MACVIA-LR of Montpellier, France and aims to provide an active and healthy life to rhinitis sufferers and to those with asthma multimorbidity across the life cycle, whatever their gender or socio-economic status, in order to reduce health and social inequities incurred by the disease and to improve the digital transformation of health and care. The ultimate goal is to change the management strategy in chronic diseases. METHODS: MASK implements ICT technologies for individualized and predictive medicine to develop novel care pathways by a multi-disciplinary group centred around the patients. STAKEHOLDERS: Include patients, health care professionals (pharmacists and physicians), authorities, patient's associations, private and public sectors. RESULTS: MASK is deployed in 23 countries and 17 languages. 26,000 users have registered. EU GRANTS 2018: MASK is participating in EU projects (POLLAR: impact of air POLLution in Asthma and Rhinitis, EIT Health, DigitalHealthEurope, Euriphi and Vigour). LESSONS LEARNT: (i) Adherence to treatment is the major problem of allergic disease, (ii) Self-management strategies should be considerably expanded (behavioural), (iii) Change management is essential in allergic diseases, (iv) Education strategies should be reconsidered using a patient-centred approach and (v) Lessons learnt for allergic diseases can be expanded to chronic diseases.

Long-term adherence to ambulatory initiated continuous positive airway pressure in non-syndromic OSA children.

PURPOSE: In children, the usual indications for continuous positive airway pressure (CPAP) are residual OSA after adenotonsillectomy and/or persistent OSA due to obesity. Data concerning adherence (hours/night) following ambulatory CPAP initiation are scarce. METHODS: An observational cohort of 78 children was followed over 2 years. All exhibited sleep-disordered breathing (SDB) symptoms, were assessed by polysomnography, and prescribed CPAP. CPAP was initiated at hospital for 10 children. RESULTS: OSA children, mean age 10.4 ± 3.2 years, were mostly males (75.6%), with a mean body mass index of 21.2 ± 7.3 kg/m2, and mean apnea+hypopnea index of 12.2 ± 10.6 events/hour. Seventy-two children were still on CPAP at 3 months, 63 at 6 months, 55 at 1 year, and 34 at 2 years. CPAP was discontinued thanks to rehabilitation programs, dento-facial orthopedics, and/or weight loss. Mean CPAP adherence at 1, 3, 6, 12, and 24 months was respectively 6.1 ± 2.8, 6.2 ± 2.6, 6.2 ± 2.8, 6.3 ± 2.8, and 7.0 ± 2.7 h/night. There was a trend towards higher CPAP adherence and younger age, primary versus middle/high school attendance, higher baseline apnea+hypopnea index, and neurocognitive disorders. CONCLUSION: In our population, mean CPAP adherence defined in hours per night was high and did not decrease during the 24-month follow-up. These findings support the feasibility of ambulatory CPAP initiation in non-syndromic OSA. The high CPAP adherence is expected to be associated with improvements in neurocognition, and in metabolic and cardiovascular parameters.

Obstructive sleep apnoea syndrome in patients living with diabetes: Which patients should be screened?

AIM: Because type 2 diabetes (T2D) is related to obesity, it is often associated with obstructive sleep apnoea syndrome (OSAS), although OSAS is also frequently diagnosed in patients with type 1 diabetes (T1D) and may promote gestational diabetes. Thus, this systematic review of the scientific evidence aimed to evaluate the epidemiological association between OSAS and all forms of diabetes, the current understanding of the pathophysiological mechanisms behind these associations, the expected benefits and limitations of OSAS treatment in patients with diabetes and, finally, to propose which patients require screening for OSAS. METHODS: A panel comprising French expert endocrinologists and pneumologists was convened. Two of these experts made a search of the relevant literature for each subpart of the present report; all panel experts then critically reviewed the entire report separately as well as collectively. RESULTS: There is little evidence to support the notion that OSAS treatment improves glycated haemoglobin, although it may improve nighttime blood glucose control and insulin sensitivity. However, there is robust evidence that OSAS treatment lowers 24-h blood pressure. CONCLUSION: The high prevalence of OSAS in patients with T1D and T2D justifies screening for the syndrome, which should be based on clinical symptoms, as the benefits of OSAS treatment are mainly improvement of symptoms related to sleep apnoea. There are also several clinical situations wherein screening for OSAS seems justified in patients with diabetes even when they have no symptoms, particularly to optimalize control of blood pressure in cases of resistant hypertension and microvascular complications.

MASK 2017: ARIA digitally-enabled, integrated, person-centred care for rhinitis and asthma multimorbidity using real-world-evidence.

mHealth, such as apps running on consumer smart devices is becoming increasingly popular and has the potential to profoundly affect healthcare and health outcomes. However, it may be disruptive and results achieved are not always reaching the goals. Allergic Rhinitis and its Impact on Asthma (ARIA) has evolved from a guideline using the best evidence-based approach to care pathways suited to real-life using mobile technology in allergic rhinitis (AR) and asthma multimorbidity. Patients largely use over-the-counter medications dispensed in pharmacies. Shared decision making centered around the patient and based on self-management should be the norm. Mobile Airways Sentinel networK (MASK), the Phase 3 ARIA initiative, is based on the freely available MASK app (the Allergy Diary, Android and iOS platforms). MASK is available in 16 languages and deployed in 23 countries. The present paper provides an overview of the methods used in MASK and the key results obtained to date. These include a novel phenotypic characterization of the patients, confirmation of the impact of allergic rhinitis on work productivity and treatment patterns in real life. Most patients appear to self-medicate, are often non-adherent and do not follow guidelines. Moreover, the Allergy Diary is able to distinguish between AR medications. The potential usefulness of MASK will be further explored by POLLAR (Impact of Air Pollution on Asthma and Rhinitis), a new Horizon 2020 project using the Allergy Diary.

Hypoxic conditioning and the central nervous system: A new therapeutic opportunity for brain and spinal cord injuries?

Central nervous system diseases are among the most disabling in the world. Neuroprotection and brain recovery from either acute or chronic neurodegeneration still represent a challenge in neurology and neurorehabilitation as pharmacology treatments are often insufficiently effective. Conditioning the central nervous system has been proposed as a potential non-pharmacological neuro-therapeutic. Conditioning refers to a procedure by which a potentially deleterious stimulus is applied near to but below the threshold of damage to the organism to increase resistance to the same or even different noxious stimuli given above the threshold of damage. Hypoxic conditioning has been investigated in several cellular and preclinical models and is now recognized as inducing endogenous mechanisms of neuroprotection. Ischemic, traumatic, or chronic neurodegenerative diseases can benefit from hypoxic conditioning strategies aiming at preventing the deleterious consequences or reducing the severity of the pathological condition (preconditioning) or aiming at inducing neuroplasticity and recovery (postconditioning) following central nervous system injury. Hypoxic conditioning can consist in single (sustained) or cyclical (intermittent, interspersed by short period of normoxia) hypoxia stimuli which duration range from few minutes to several hours and that can be repeated over several days or weeks. This mini-review addresses the existing evidence regarding the use of hypoxic conditioning as a potential innovating neuro-therapeutic modality to induce neuroprotection, neuroplasticity and brain recovery. This mini-review also emphasizes issues which remain to be clarified and future researches to be performed in the field. Impact statement Neuroprotection and brain recovery from either acute or chronic neurodegeneration still represent a challenge in neurology and neurorehabilitation. Hypoxic conditioning may represent a harmless and efficient non-pharmacological new therapeutic modality in the field of neuroprotection and neuroplasticity, as supported by many preclinical data. Animal studies provide clear evidence for neuroprotection and neuroplasticity induced by hypoxic conditioning in several models of neurological disorders. These studies show improved functional outcomes when hypoxic conditioning is applied and provides important information to translate this intervention to clinical practice. Some studies in humans provide encouraging data regarding the tolerance and therapeutic effects of hypoxic conditioning strategies. The main issues to address in future research include the definition of the appropriate hypoxic dose and pattern of exposure, the determination of relevant physiological biomarkers to assess the effects of the treatment and the evaluation of combined strategies involving hypoxic conditioning and other pharmacological or non-pharmacological treatments.

Fixed-pressure CPAP versus auto-adjusting CPAP: comparison of efficacy on blood pressure in obstructive sleep apnoea, a randomised clinical trial.

BACKGROUND: Millions of individuals with obstructive sleep apnoea (OSA) are treated by CPAP aimed at reducing blood pressure (BP) and thus cardiovascular risk. However, evidence is scarce concerning the impact of different CPAP modalities on BP evolution. METHODS: This double-blind, randomised clinical trial of parallel groups of patients with OSA indicated for CPAP treatment compared the efficacy of fixed-pressure CPAP (FP-CPAP) with auto-adjusting CPAP (AutoCPAP) in reducing BP. The primary endpoint was the change in office systolic BP after 4 months. Secondary endpoints included 24 h BP measurements. RESULTS: Patients (322) were randomised to FP-CPAP (n=161) or AutoCPAP (n=161). The mean apnoea+hypopnoea index (AHI) was 43/h (SD, 21); mean age was 57 (SD, 11), with 70% of males; mean body mass index was 31.3 kg/m(2) (SD, 6.6) and median device use was 5.1 h/night. In the intention-to-treat analysis, office systolic blood pressure decreased by 2.2 mm Hg (95% CI -5.8 to 1.4) and 0.4 mm Hg (-4.3 to 3.4) in the FP-CPAP and AutoCPAP group, respectively (group difference: -1.3 mm Hg (95% CI -4.1 to 1.5); p=0.37, adjusted for baseline BP values). 24 h diastolic BP (DBP) decreased by 1.7 mm Hg (95% CI -3.9 to 0.5) and 0.5 mm Hg (95% CI -2.3 to 1.3) in the FP-CPAP and AutoCPAP group, respectively (group difference: -1.4 mm Hg (95% CI -2.7 to -0.01); p=0.048, adjusted for baseline BP values). CONCLUSIONS: The result was negative regarding the primary outcome of office BP, while FP-CPAP was more effective in reducing 24 h DBP (a secondary outcome). TRIAL REGISTRATION NUMBER: NCT01090297.

Glucose tolerance and cardiovascular risk biomarkers in non-diabetic non-obese obstructive sleep apnea patients: Effects of long-term continuous positive airway pressure.

BACKGROUND: Insulin resistance, glucose dyshomeostasis and oxidative stress are associated to the cardiovascular consequences of obstructive sleep apnea (OSA). The effects of a long-term continuous positive airway pressure (LT-CPAP) treatment on such mechanisms still remain conflicting. OBJECTIVE: To investigate the effect of LT-CPAP on glucose tolerance, insulin sensitivity, oxidative stress and cardiovascular biomarkers in non-obese non-diabetic OSA patients. PATIENTS & METHODS: Twenty-eight apneic, otherwise healthy, men suffering from OSA (mean age = 48.9 ± 9.4 years; apnea-hypopnea index = 41.1 ± 16.1 events/h; BMI = 26.6 ± 2.8 kg/m(2); fasting glucose = 4.98 ± 0.37 mmol/L) were evaluated before and after LT-CPAP by an oral glucose tolerance test (OGTT), measuring plasma glucose, insulin and proinsulin. Glycated hemoglobin, homeostasis model assessment resistance insulin, blood lipids, oxidative stress, homocysteine and NT-pro-brain natriuretic peptide (NT-proBNP) were also measured. RESULTS: LT-CPAP treatment lasted 13.9 ± 6.5 months. At baseline, the time spent at SaO2<90%, minimal and mean SaO2 were associated with insulin area under the curve during OGTT (r = 0.448, P = 0.011; r = -0.382; P = 0.047 and r = -0.424; P = 0.028, respectively) and most other glucose/insulin homeostasis biomarkers, as well as with homocysteine (r = 0.531, P = 0.006; r = -0.487; P = 0.011 and r = -0.409; P = 0.034, respectively). LT-CPAP had no effect on all the OGTT-related measurements, but increased plasma total antioxidant status (+7.74%; P = 0.035) in a duration-dependent manner (r = 0.607; P < 0.001), and decreased both homocysteine (-15.2%; P = 0.002) and NT-proBNP levels (-39.3%; P = 0.002). CONCLUSIONS: In non-obese non-diabetic OSA patients, nocturnal oxygen desaturation is strongly associated to insulin resistance. LT-CPAP does not improve glucose homeostasis nor insulin sensitivity but has a favorable effect on antioxidant capacity and cardiovascular risk biomarkers.