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Background: The "Baveno classification" replaced the apnoea-hypopnoea index (AHI) with symptoms and comorbidities for treatment indication in obstructive sleep apnoea (OSA). This study evaluates a modified Baveno classification which adds a validated cardiovascular disease (CVD) risk score and acknowledges severe breathing disturbances., Method: OSA patients from the European Sleep Apnoea Database (ESADA) were retrospectively allocated into CVD risk groups 1-3 based on the SCORE2 risk prediction model and European Society of Cardiology guidelines. AHI ≥30 events·h -1 conferred strong treatment indication. When AHI was <30 events·h -1 , symptoms and CVD risk dictated allocation to the weak, intermediate or strong treatment indication group. Changes in Epworth Sleepiness Scale (ESS) score and office systolic blood pressure (SBP) at follow-up (12-24 months) under positive airway pressure (PAP) were assessed., Results: 8625 patients were analysed (29% female; median (interquartile range) age 56 (49-64) years and body mass index 31.9 (28.4-36.3) kg·m -2 ). Treatment indication was weak in 501 (6%), intermediate in 2085 (24%) and strong in 6039 (70%). There was a continuous increase in age, SBP, C-reactive protein and glycosylated haemoglobin from weak to strong (p<0.001). PAP prescription increased from 52% to 64% to 93% (weak to strong; p<0.001). The change in ESS score was -2, -4 and -5, respectively (p<0.001). Reductions of ≥3 mmHg median SBP occurred when AHI was ≥30 events·h -1 and in symptomatic patients with CVD risk levels >1 when AHI was <30 events·h -1 ., Conclusion: This analysis provides supporting evidence for the key role of CVD risk assessment and severe breathing disturbances in the identification of OSA patients most likely to benefit from treatment., Competing Interests: Conflict of interest: S. Matthes reports travel grants from Chiesi and Boehringer. L. Grote has performed educational activities for AstraZeneca, Lundbeck, ResMed, Philipps and Itamar, has interests in two patents licensed to Desitin GMBH, and provides medical advice to Onera BV. J. Hedner has provided scientific advice to SomnoMed and is a part owner of two patents, outside the submitted work. J-L. Pépin is funded by the French National Research Agency in the framework of the “Investissements d'avenir” programme (ANR-15-IDEX-02) and “e-health and integrated care and trajectories medicine and MIAI artificial intelligence” (ANR-19-P3IA-0003) Chairs of excellence from the Grenoble Alpes University; and reports income related to medical education from ResMed, Bioprojet, Jazz and Zoll. W.T. McNicholas reports participation in the Horizon 2020 research and innovation programme under grant agreement number 965417: Sleep Revolution, and is a board member at ESRS. J. Verbraecken reports grants and fees from SomnoMed, AirLiquide, Atos Medical, Vivisol, Mediq Tefa, Medidis, Micromed OSG, Bioprojet, Desitin, Epilog, Idorsia, Inspire Medical Systems, Löwenstein Medical, Ectosense, Philips, ProSomnus, ResMed, Sefam, SD Worx, SOS Oxygène, Tilman, Total Care, Vlaamse Gemeenschap, Vlerick and Zoll Itamar, outside the submitted work, and consultancy for Bioprojet and Epilog. G. Parati reports honoraria for lectures from Omron, SOMNOmedics, Merck and ReCor. W.J. Randerath reports grants and personal fees from Philips Respironics, Loewenstein Medical, ResMed, Bayer Vital, Bioprojet and Vanda Pharma, outside the submitted work. The remaining authors have no potential conflicts of interest to disclose., (Copyright ©The authors 2024. For reproduction rights and permissions contact permissions@ersnet.org.)

Obstructive sleep apnoea (OSA) is a major challenge for physicians and healthcare systems throughout the world. The high prevalence and the impact on daily life of OSA oblige clinicians to offer effective and acceptable treatment options. However, recent evidence has raised questions about the benefits of positive airway pressure therapy in ameliorating comorbidities.An international expert group considered the current state of knowledge based on the most relevant publications in the previous 5 years, discussed the current challenges in the field, and proposed topics for future research on epidemiology, phenotyping, underlying mechanisms, prognostic implications and optimal treatment of patients with OSA.The group concluded that a revision to the diagnostic criteria for OSA is required to include factors that reflect different clinical and pathophysiological phenotypes and relevant comorbidities ( e.g. nondipping nocturnal blood pressure). Furthermore, current severity thresholds require revision to reflect factors such as the disparity in the apnoea-hypopnoea index (AHI) between polysomnography and sleep studies that do not include sleep stage measurements, in addition to the poor correlation between AHI and daytime symptoms such as sleepiness. Management decisions should be linked to the underlying phenotype and consider outcomes beyond AHI., Competing Interests: Conflict of interest: W. Randerath reports grants and personal fees (travel grants and speaking fees) from Heinen & Löwenstein, Weinmann, ResMed, Inspire and Philips Respironics, outside the submitted work. L. Ferini-Strambi reports personal fees from Philips Respironics (honoraria for a lecture and for chairing a scientific meeting in 2015–2016, none of which involved promotion of company products and there was no influence on lecture content) and ResMed (honoraria for participating in an advisory board), outside the submitted work. R. Farre reports other fees from ResMed (a contract between the company and the University of Barcelona (Fundació Bosch Gimpera) for assessing automatic CPAP devices in a bench test) and other fees from ANTADIR (a contract between the company and the University of Barcelona (Fundació Bosch Gimpera) for assessing automatic CPAP devices in a bench test), outside the submitted work. L. Grote reports grants and personal fees (speakers’ bureau) from ResMed and Philips, personal fees from Breas Mecical (consultancy), personal fees and nonfinancial support from Heinen & Löwenstein (consultancy), and grants from the ERS, during the conduct of the study; and personal fees (speakers’ bureau) from AstraZeneca, outside the submitted work. In addition, L. Grote has a patent on pharmacological treatment of OSA pending. J. Hedner has together with the ESADA study group received grants from ResMed and Philips Respironics to enable the ESADA database. He has also received personal speaker bureau fees from AstraZeneca, Takeda and Bayer. M. Kohler reports personal fees from Bayer (advisor fees), outside the submitted work. J-L. Pepin reports unrestricted research grants from Philips, ResMed, Fisher & Paykel, Fondation de la recherche medicale, Direction de la recherche Clinique du CHU de Grenoble and Fond de dotation “Agir pour les maladies chroniques”, and personal fees (travel grants and lecture fees) from Perimetre, Philips, Fisher & Paykel, ResMed, AstraZeneka, SEFAM, Agiradom and Teva, during the conduct of the study. J. Verbraecken reports other fees (sponsoring courses) from Koninklijke Philips Respironics, ResMed, Fisher & Paykel, NightBalance, Heinen & Löwenstein, AirLiquide, Accuramed, OSG, Medidis, MediqTefa, Wave Medical, Vivisol, TotalCare, SomnoMed, UCB Pharma, Olympus Belgium, Takeda, Masimo and Linde Healthcare, outside the submitted work. W.T. McNicholas reports personal fees from Philips Respironics (honoraria for lectures, but none of these lectures related to promotion of company products and the lecture content was not in any way influenced by the company), outside the submitted work., (Copyright ©ERS 2018.)

The complexity of central breathing disturbances during sleep has become increasingly obvious. They present as central sleep apnoeas (CSAs) and hypopnoeas, periodic breathing with apnoeas, or irregular breathing in patients with cardiovascular, other internal or neurological disorders, and can emerge under positive airway pressure treatment or opioid use, or at high altitude. As yet, there is insufficient knowledge on the clinical features, pathophysiological background and consecutive algorithms for stepped-care treatment. Most recently, it has been discussed intensively if CSA in heart failure is a "marker" of disease severity or a "mediator" of disease progression, and if and which type of positive airway pressure therapy is indicated. In addition, disturbances of respiratory drive or the translation of central impulses may result in hypoventilation, associated with cerebral or neuromuscular diseases, or severe diseases of lung or thorax. These statements report the results of an European Respiratory Society Task Force addressing actual diagnostic and therapeutic standards. The statements are based on a systematic review of the literature and a systematic two-step decision process. Although the Task Force does not make recommendations, it describes its current practice of treatment of CSA in heart failure and hypoventilation., (Copyright ©ERS 2017.)

Modafinil is used internationally to treat residual sleepiness despite continuous positive airway pressure in obstructive sleep apnoea (res-OSA). In 2011, the European Medicines Agency removed the indication based on an unfavourable risk-benefit profile in two trials for efficacy and all accumulated safety data. We performed a meta-analysis of all randomised controlled trials of modafinil (or armodafinil) in res-OSA to quantify efficacy and safety.We systematically searched and assessed studies from major databases, conferences and trials registries to find randomised, placebo-controlled trials of modafinil/armodafinil for ≥2 weeks in adult res-OSA treating sleepiness.We analysed 10 of the 232 articles identified that met inclusion criteria (1466 patients). Modafinil/armodafinil improved the Epworth Sleepiness Scale score (2.2 points, 95% CI 1.5-2.9) and the Maintenance of Wakefulness Test over placebo (3 min, 95% CI 2.1-3.8 min). Modafinil/armodafinil tripled adverse events and doubled adverse events leading to withdrawal but did not increase serious adverse events (hospitalisations or death).Modafinil and armodafinil improve subjective and objective daytime sleepiness in res-OSA. We believe our analysis is a fairer analysis of the risk-benefit profile of this indication. Clinicians may want to use this data to balance the risks and benefits on a case-by-case basis with their patients., (Copyright ©ERS 2016.)

Systemic hypertension is associated with obstructive sleep apnoea syndrome (OSAS) but the pathophysiological mechanisms are incompletely understood. A collaborative European network of 24 sleep centres established a European Sleep Apnoea Database to evaluate cardiovascular morbidity associated with OSAS. 11 911 adults referred with suspected OSAS between March 2007 and September 2013 underwent overnight sleep studies, either cardiorespiratory polygraphy or polysomnography. We compared the predictive value of the apnoea-hypopnoea index (AHI) and 4% oxygen desaturation index (ODI) for prevalent hypertension, adjusting for relevant covariates including age, smoking, obesity, dyslipidaemia and diabetes. Among patients (70% male, mean±sd age 52±12 years), 78% had AHI>5 events·h(-1) and 41% systemic hypertension. Both AHI and ODI independently related to prevalent hypertension after adjustment for relevant covariates (p<0.0001 for linear trend across quartiles (Q) of severity for both variables). However, in multiple regression analysis with both ODI and AHI in the model, ODI was, whereas AHI was not, independently associated with prevalent hypertension: odds ratios (95% CI) for Q4 versus Q1 regarding ODI were 2.01 (1.61-2.51) and regarding AHI were 0.92 (0.74-1.15) (p<0.0001 and p=0.3054, respectively). This cross sectional study suggests that chronic intermittent hypoxia plays an important role in OSAS-related hypertension., (©ERS 2014.)

Obstructive sleep apnoea (OSA) is associated with increased risk of dysglycaemia but the intimate link of these conditions with obesity makes discerning an independent relationship between them challenging. Glycosylated haemoglobin (HbA1c) levels predict adverse cardiovascular outcomes in nondiabetics but there is a lack of population-level data exploring the relationship of HbA1c with OSA. A cross-sectional analysis of 5294 participants in the multinational European Sleep Apnoea Cohort (European Sleep Apnoea Database) study was performed, assessing the relationship of OSA severity with HbA1c levels in nondiabetic subjects, with adjustment for confounding factors. HbA1c levels correlated significantly with OSA severity in univariate analysis. Following adjustment for confounding factors, apnoea-hypopnoea index (AHI) (standardised β 0.158; p<0.001), along with nocturnal hypoxaemia, predicted HbA1c. Adjusted mean HbA1c levels were lower in the lowest AHI quartile (5.24%, 95% CI 5.21-5.27%) than in the second (5.37%, 95% CI 5.34-5.40%), third (5.44%, 95% CI 5.41-5.47%) or highest (5.50%, 95% CI 5.46-5.53%) quartiles. Subjects in the higher quartiles had significantly greater adjusted odds ratios of HbA1c level ≥6.0% than those in the first quartile. In stratified analyses, OSA severity predicted glycaemic health irrespective of sleep study modality, sex, obesity or daytime sleepiness. OSA severity independently predicts glycaemic health in nondiabetic subjects. Further studies should assess the impact of OSA treatment on glycaemic health and elucidate underlying mechanisms., (© ERS 2014.)

Carbonic anhydrase inhibition reduces apnoeic events in sleep disordered breathing. Zonisamide inhibits carbonic anhydrase, and induces weight loss in obese patients. This study explored the relative influence of these two properties, which may both alleviate obstructive sleep apnoea (OSA). Continuous positive airway pressure (CPAP) was used as a standard care comparator. 47 patients with moderate-to-severe OSA and a body mass index of 27-35 kg·m(-2) were randomised to receive either zonisamide, placebo or CPAP for 4 weeks. The open extension phase (20 weeks) compared CPAP and zonisamide. Polysomnography, biochemistry and symptoms were evaluated. At 4 weeks, zonisamide reduced apnoea/hypopnoea index (AHI) by a mean±sd 33±39% and oxygen desaturation index by 28±31% (p=0.02 and 0.014, respectively; placebo adjusted). The mean compliance adjusted reduction of AHI after zonisamide and CPAP was 13 and 61%, respectively, (p=0.001) at 24 weeks. Body weight was marginally changed at 4 weeks, but reduced after zonisamide and increased after CPAP at 24 weeks (-2.7±3.0 kg versus 2.3±2.0 kg, p<0.001). Zonisamide decreased bicarbonate at 4 and 24 weeks. Side-effects were more common after zonisamide. Zonisamide reduced OSA independent of body weight potentially by mechanisms related to carbonic anhydrase inhibition. The effect was less pronounced than that obtained by CPAP., (© ERS 2014.)

This article is aimed at addressing the current state-of-the-art in epidemiology, pathophysiology, diagnostic procedures and treatment options for appropriate management of obstructive sleep apnoea (OSA) in cardiovascular (in particular hypertensive) patients, as well as for the management of cardiovascular diseases (in particular arterial hypertension) in OSA patients. The present document is the result of work performed by a panel of experts participating in the European Union COST (Cooperation in Scientific and Technological research) Action B26 on OSA, with the endorsement of the European Respiratory Society and the European Society of Hypertension. In particular, these recommendations are aimed at reminding cardiovascular experts to consider the occurrence of sleep-related breathing disorders in patients with high blood pressure. They are also aimed at reminding respiration experts to consider the occurrence of hypertension in patients with respiratory problems at night.

Sleep apnoea is associated with increased mortality in sleep clinic and community population groups. It is unclear whether a clinical report of sleep apnoea results in additional mortality risk in patients with severe obesity. The Swedish Obese Subjects (SOS) study is a nonrandomised controlled trial of bariatric surgery versus conventional treatment for the treatment of severe obesity and its complications (mean ± SD body mass index 41 ± 5 kg · m(-2)). The presence or absence of sleep apnoea (witnessed pauses in breathing) was determined by self-reporting at baseline in 3,953 patients who were observed for 54,236 person-yrs (mean 13.5 maximum 21.0 yrs). Sleep apnoea was reported by 934 (23.6%) patients at baseline and was a significant univariate predictor of mortality (hazard ratio (95% CI) 1.74 (1.40-2.18)). In a range of multivariate models of mortality risk, controlling for ≤ 16 other potential confounders and established mortality risk factors, sleep apnoea remained a significant prognostic factor (fully adjusted model 1.29 (1.01-1.65)). Self-reported sleep apnoea is an independent prognostic marker of all-cause mortality in obese patients.

The European Sleep Apnoea Database (ESADA) reflects a network of 22 sleep disorder centres in Europe enabled by a COST action B26 programme. This ongoing project aims to describe differences in standard clinical care of patients with obstructive sleep apnoea (OSA) and to establish a resource for genetic research in this disorder. Patients with suspected OSA are consecutively included and followed up according to local clinical standards. Anthropometrics, medical history, medication, daytime symptoms and sleep data (polysomnography or cardiorespiratory polygraphy) are recorded in a structured web-based report form. 5,103 patients (1,426 females, mean±sd age 51.8±12.6 yrs, 79.4% with apnoea/hypopnoea index (AHI) ≥5 events·h(-1)) were included from March 15, 2007 to August 1, 2009. Morbid obesity (body mass index ≥35 kg·m(-2)) was present in 21.1% of males and 28.6% of females. Cardiovascular, metabolic and pulmonary comorbidities were frequent (49.1%, 32.9% and 14.2%, respectively). Patients investigated with a polygraphic method had a lower AHI than those undergoing polysomnography (23.2±23.5 versus 29.1±26.3 events·h(-1), p<0.0001). The ESADA is a rapidly growing multicentre patient cohort that enables unique outcome research opportunities and genotyping. The first cross-sectional analysis reveals a high prevalence of cardiovascular and metabolic morbidity in patients investigated for OSA.

Obstructive sleep apnoea (OSA) is associated with oxygen desaturation to a varying degree. A patent foramen ovale (PFO) may allow interatrial right-to-left shunting. The hypothesis of the current study was that oxygen desaturation will occur more often, in proportion to the frequency of respiratory disturbances, in OSA subjects with PFO than in those without. In a group of 209 subjects diagnosed with OSA, the proportion of desaturation to respiratory events was calculated as the ratio of oxygen desaturation index (ODI)/apnoea-hypopnoea index (AHI). A total of 15 cases with high proportional desaturation (ODI/AHI >or=0.66) were individually matched with 15 controls with low proportional desaturation (ODI/AHI or=20 bubbles passed over from the right to the left atrium after a single injection. The prevalence of large PFO was nine out of 15 (60%) in the high proportional desaturation group versus two out of 15 (13%) in the low proportional desaturation group. The median number of passing bubbles was positively correlated to minimum oxygen saturation among those with PFO. In conclusion, oxygen desaturation occurs more often, in proportion to the frequency of respiratory disturbances, in obstructive sleep apnoea subjects with a patent foramen ovale than in those without.

An increased incidence of cardiovascular disease has previously been reported in middle-aged males during a follow-up period of 7 yrs. The aim of the present study was to address the incidence of coronary artery disease (CAD) in a larger sample without any heart disease at baseline. The population comprised 308 snorers (245 males and 63 females) with a mean +/- sd age of 49.0 +/- 9.9 yrs in 1991. Data were collected via the Swedish Hospital Discharge Register, National Cause of Death Registry, clinical charts and questionnaires. Over 7 yrs, CAD was observed in 17 (16.2%) of 105 patients with obstructive sleep apnoea (OSA; overnight (6 h) oxygen desaturations > or =30 events) compared with 11 (5.4%) of 203 snorers without OSA. OSA diagnosis at baseline was associated with an increased risk of development of CAD in a multivariate model. In the OSA group, CAD was confirmed in 16 (24.6%) of 65 incompletely treated patients compared with one (3.9%) of 26 efficiently treated subjects. Efficient treatment of OSA reduced this risk. It is concluded that middle-aged sleep apnoeics are at high risk of developing coronary artery disease if they are not treated efficiently, which should be considered in cardiovascular disease prevention models.

Obstructive sleep apnoea (OSA) is a recognised risk factor for hypertension (HT). The current authors investigated confounders of this association in a sex-balanced community-based sample of patients with HT (n=161) from the Skaraborg Hypertension and Diabetes Project (n=1,149) and normotensive controls (n=183) from an age and sex stratified community-based population sample (n=1,109). All participants underwent ambulatory home polysomnography. Severe OSA (apnoea-plus-hypopnoea index (AHI)>or=30 events.h-1) was found in 47 and 25% of hypertensive and normotensive males, respectively. The corresponding numbers in females were 26 and 24%, respectively. The odds ratio (OR) for HT increased across AHI tertiles from 1.0 to 2.1 (95% confidence interval: 0.9-4.5) and 1.0 to 3.7 (95% CI: 1.7-8.2) in males, but not in females where the OR increased from 1.0 to 1.8 (95% CI: 0.8-3.9) and 1.0 to 1.6 (95% CI: 0.7-3.5). Regression analysis correcting for age, body mass index (or waist-hip ratio) and smoking did not eliminate the association between OSA and HT in males. The present data suggest that obstructive sleep apnoea is highly prevalent in both the general population and in patients with known hypertension. The contribution of obstructive sleep apnoea to hypertension risk may be sex dependent and higher in males than in females.

Studies addressing the relationship between obstructive sleep apnoea (OSA) and sympathoadrenal activity have been criticized for poor control of factors known to confound sympathetic function, including hypertension. The aim of this study was to investigate the relationship between OSA and urinary catecholamines in a population-based sample of hypertensive males. In 1994, 2,668 males aged 40-79 yrs answered a questionnaire regarding sleep disorders and somatic diseases. Of those who reported hypertension, an age-stratified sample of 116 was selected for monitoring of breathing during sleep and overnight urine analysis. Subjects with OSA, defined as apnoea-hypopnoea index > or = 10 x h(-1), had higher concentrations of urinary normetanephrine (182+/-57 versus 141+/-45 micromol x mol(-1) creatinine, p<0.001) and metanephrine (70+/-28 versus 61+/-28 micromol mol(-1) creatinine, p<0.05) in comparison to subjects without OSA. In a multiple regression analysis, there was an association between variables of sleep-disordered breathing and normetanephrine and metanephrine concentrations, independent of major confounding factors. The authors concluded that, in a population-based sample of hypertensive males, obstructive sleep apnoea is associated with increased urinary concentrations of extraneuronal metabolites of catecholamines independent of major confounding factors, suggesting increased sympathoadrenal activity. Elevated sympathoadrenal activity may explain the increased cardiovascular morbidity associated with obstructive sleep apnoea.

Correct assessment of the overall treatment effectiveness requires knowledge about therapy compliance and efficacy. This study aimed to determine overall long-term apnoea alleviation after continuous positive airway pressure (CPAP) in a complete sleep laboratory cohort. Out of 209 consecutive CPAP candidates (mean age 57+/-12 yrs, body mass index (BMI) 30.0+/-5.1 kg x m2, respiratory disturbance index (RDI) 32.9+/-29 h), follow-up treatment was performed in 149 of them at 9, 18 and 30 months after CPAP prescription. Compliance with CPAP (machine run time/days CPAP available) was adjusted for the individual subjective sleep-time. Apnoea alleviation was defined as adjusted compliance multiplied by the CPAP effect (RDI with CPAP applied), remaining RDI was calculated. The baseline RDI, age or BMI in 75 patients, who did not tolerate nasal continuous positive airway pressure (nCPAP), did not differ from those accepting CPAP (acceptors, n=74). In acceptors at 9 months follow-up RDI with CPAP applied was 1.4+/-2.6 (CPAP effect, n=66), mean CPAP use was 3.6+/-2.5 x 24 h(-1) (n=68), mean apnoea alleviation was 52.4+/-32.0% (range 1-100%, n=47), the average remaining whole-night RDI was 17.8+/-26. At 9, 18 and 30 months (n=47), the mean daily CPAP use increased from 3.6+/-2.5 h to 4.1+/-2.5 h and 4.4+/-2.4 h (p<0.01). Effectiveness of continuous positive airway pressure is potentially high but acceptance was low. When accounting for sleep-time, its actual effect and use, only 50% adjusted continuous positive airway pressure effectiveness was observed.

Previous studies of sleep and breathing suggest an independent association between coronary artery disease (CAD) and obstructive sleep apnoea (OSA) in middle-aged males and females. These studies, however, were criticized because they did not properly adjust for all important confounding factors. In order to better control for the impact of these confounders, a case-control study was performed, matching for age, sex and body mass index (BMI), and additionally adjusting for hypertension, hypercholesterolemia, diabetes mellitus and current smoking. A consecutive selection of 62 patients (44 males and 18 females, mean age 69 yrs, range 44-88 yrs) requiring intensive care for angina pectoris or myocardial infarction at the County Hospital of Skaraborg, Skövde, Sweden, as well as 62 age-, sex- and BMI- matched control subjects without history or signs of heart disease underwent an overnight sleep/ventilatory monitoring study. The time interval between discharge from the intensive care unit and the overnight study ranged between 4 and 21 months. OSA, defined as a Respiratory Disturbance Index (RDI) of > or =10 x h(-1), was present in 19 CAD patients but only in eight control subjects (p=0.017). Using a univariate logistic regression analysis, current smoking (odds ratio (OR) 8.1, 95% confidence interval (CI) 2.2-29.0), diabetes mellitus (OR 4.2, 95% CI 1.1-16.1) and OSA (OR 3.0, 95% CI 1.2-7.5), but not hypertension (OR 1.5, 95% CI 0.7-3.2) and hypercholesterolaemia (OR 1.8, 95% CI 0.7-4.1) were significantly correlated with CAD. In a multiple logistic regression model, current smoking (OR 9.8, 95% CI 2.6-36.5), diabetes mellitus (OR 4.2, 95% CI 1.1-17.1) and OSA (OR 3.1, 95% CI 1.2-8.3) all remained independently associated with CAD. In summary, these data suggest a high occurrence of obstructive sleep apnoea in middle-aged and elderly patients with coronary artery disease requiring intensive care, which should be taken into account when considering risk factors for coronary artery disease.

Two studies are presented, with the aim of establishing the dose potency ratio for salbutamol given via Turbuhaler and via a pressurized metered-dose inhaler (pMDI). Both studies were of a double-blind, randomized design. Outpatients with mild-to-moderate chronic reversible airway obstruction were given single doses of salbutamol administered via Turbuhaler and via pMDI. Efficacy and safety variables were measured before and during 6 h after each dose. The first study was a four-way crossover study including 12 patients. The salbutamol doses given were: 50, 100 and 2x100 microg via Turbuhaler and 2x100 microg via pMDI (Ventolin). The study showed that 2x100 microg of salbutamol inhaled via Turbuhaler is more potent than 2x100 microg salbutamol inhaled via a pMDI, and that 100 microg salbutamol via Turbuhaler is at least as potent as 2x100 microg salbutamol inhaled via a pMDI. The second study including 50 patients was a placebo-controlled five-way crossover, study. Two doses of salbutamol via Turbuhaler, 50 and 2x100 microg, and via pMDI, 100 and 2x200 microg, were given. There was a dose-dependent response in forced expiratory volume in one second (FEV1) for both inhalers. Adjusted for differences in baseline FEV1 values, the estimated relative dose potency for Turbuhaler versus pMDI was 1.98:1 (95% confidence interval 12-3.2). These studies showed that the same bronchodilating effect can be achieved when half the dose of salbutamol given via a conventional pressurized metered-dose inhaler is given via Turbuhaler.

Twelve patients with severe obstructive sleep apnoea were included in an open, long-term, prospective, follow-up study addressing the effects of nasal continuous positive airway pressure (CPAP) on sympathetic activity, cardiac structure and blood pressure. Plasma norepinephrine (P-NE) (daytime at rest), daytime and night-time urinary excretion of NE (U-NE), vanylmandelic acid and metanephrines, together with 24 h noninvasive blood pressure (BP) recording and Doppler-echocardiography, were assessed before and after a mean of 20.5 (range 14-26) months of CPAP. Average self-reported use of CPAP was 89% (range 65-100%) of time spent in bed. Resting daytime P-NE ranged 0.35-0.83 ng.ml-1, which is elevated compared to healthy controls. Only night-time U-NE, mean daytime BP and average 24 h BP were related to severity of OSA. Night-time metanephrine was related to daytime and night-time diastolic, as well as night-time systolic, BP. Left ventricular mass index (LVMI) at baseline was correlated to daytime systolic BP and P-NE. Long-term CPAP treatment reduced biochemical markers of sympathetic activity. P-NE decreased by approximately 50%, and daytime and night-time vanylmandelic acid and metanephrine by 32-54%. In contrast, there were no overall reductions in BP or LVMI. It is concluded that obstructive sleep apnoea is associated with high sympathetic activity both during sleep and waking periods. Urinary metanephrine excretion seemed to reflect blood pressure, but neither daytime nor night-time catecholamine excretion was directly related to disease severity in patients with severe obstructive sleep apnoea.(ABSTRACT TRUNCATED AT 250 WORDS)

We wanted to assess whether benzodiazepines worsen sleep apnoea, since their use in such patients has been controversial. Fourteen male patients with mild to moderate obstructive sleep apnoea were investigated in a placebo-controlled, double-blind study evaluating the influence of nitrazepam (NIT) on apnoea frequency and severity. Each patient was given oral nitrazepam 5 or 10 mg, or corresponding placebo, in a randomized order on three separate nights. Wash-out time was one week. A complete sleep study was undertaken at each study night. Eleven patients completed the study. Although there were individuals with marked variability in apnoea index between the three study nights, there was no significant change in apnoea index or minimum arterial oxygen saturation with any of the two nitrazepam dosages studied. Only 3 out of 11 patients had a higher apnoea index after both nitrazepam doses compared to placebo, and in these patients the increase in sleep-disordered breathing was of marginal clinical significance. Nitrazepam caused a modest increase in total sleep time and a decrease in rapid eye movement (REM) sleep. These results demonstrate that nitrazepam does not worsen sleep apnoea in patients with mild to moderate sleep apnoea. The previously reported sleep apnoea promoting effects of benzodiazepines may be restricted to a small subgroup of patients with sleep-disordered breathing.