Treatment of sleep-disordered breathing with positional therapy: long-term results.

PURPOSE: The aim of the present study was to assess the efficacy of a sleep position trainer (SPT) in patients with an established diagnosis of positional obstructive sleep apnea and to evaluate the adherence after 1-year follow-up. METHODS: Polysomnography (PSG) was performed at baseline and after 1 year of SPT use. Patients received questionnaires to assess treatment satisfaction and subjective adherence. Data on objective adherence and number of vibrations initiated by the SPT were collected from the SPT device. RESULTS: Nine out of 58 patients stopped using the SPT during the first year of treatment (16%). Thirty-four middle-aged and overweight patients underwent a PSG after 1 year of SPT use (male/female ratio, 28/6; overall apnea/hypopnea index (AHI), 16/h). A significant reduction in overall AHI to 6/h was observed using treatment (p < 0.001). The median percentage of supine sleep decreased significantly to 1% with SPT (p < 0.001). The mean objective SPT use in 28 patients was 7.3 ± 0.9 h/night and 69 ± 26% of the nights. Furthermore, 75% of the patients reported a better sleep quality since the start of SPT treatment. CONCLUSIONS: Long-term treatment with the SPT was found to be effective in reducing overall AHI. Time spent sleeping in supine position was reduced to almost zero in the continuing users. Patient satisfaction was high when using the SPT.

Quantitative CT analysis using functional imaging is superior in describing disease progression in idiopathic pulmonary fibrosis compared to forced vital capacity.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is chronic fibrosing pneumonia with an unpredictable natural disease history. Functional respiratory imaging (FRI) has potential to better characterize this disease. The aim of this study was to identify FRI parameters, which predict FVC decline in patients with IPF. METHODS: An IPF-cohort (treated with pamrevlumab for 48 weeks) was retrospectively studied using FRI. Serial CT's were compared from 66 subjects. Post-hoc analysis was performed using FRI, FVC and mixed effects models. RESULTS: Lung volumes, determined by FRI, correlated with FVC (lower lung volumes with lower FVC) (R2 = 0.61, p < 0.001). A negative correlation was observed between specific image based airway radius (siRADaw) at total lung capacity (TLC) and FVC (R2 = 0.18, p < 0.001). Changes in FVC correlated significantly with changes in lung volumes (R2 = 0.18, p < 0.001) and siRADaw (R2 = 0.15, p = 0.002) at week 24 and 48, with siRADaw being more sensitive to change than FVC. Loss in lobe volumes (R2 = 0.33, p < 0.001), increasing fibrotic tissue (R2 = 0.33, p < 0.001) and airway radius (R2 = 0.28, p < 0.001) at TLC correlated with changes in FVC but these changes already occur in the lower lobes when FVC is still considered normal. CONCLUSION: This study indicates that FRI is a superior tool than FVC in capturing of early and clinically relevant, disease progression in a regional manner.

Epidemiology and outcome of invasive pneumococcal disease among adults in Belgium, 2009-2011.

This epidemiological study examined morbidity and case fatality of invasive pneumococcal disease (IPD) in adults in Belgium as well as distribution and antibiotic susceptibility of Streptococcus pneumoniae serotypes.Adults hospitalised with microbiologically proven IPD were prospectively enrolled. The study started in 2009 with patients aged ≥50 years, whereas in 2010 and 2011, patients aged ≥18 years were included. The clinical presentation, patient profile, treatment, outcome, and mortality were recorded during hospitalisation.Outcome was also assessed one month afterdischarge. Of the 1,875 patients with IPD identified, 1,332 were included in the analysis. Bacteraemic pneumonia, affecting 1,049 of the patients, was the most frequent IPD type (79%), and chronic obstructive pulmonary disease and cancer were the main comorbidities.One-third of patients required admission to intensive care unit. A total of 208 (16%) patients died during hospitalisation and an additional 21 (2%) within one month after discharge. Case fatality rates of ≥20%were observed in patients with chronic heart failure, hepatic disease, and renal insufficiency. Serotypes 7F, 1, 19A, and 3 were the most prevalent and together accounted for 47% (569/1,214) of all IPD cases and 42% (80/189) of mortality. Of the patient isolates, 21% (255/1,204) were resistant to erythromycin and 22% (264/1,204) to tetracycline. Penicillin non-susceptibility was mostly found in serotype 19A isolates. These baseline data are essential when assessing the impact of pneumococcal conjugate vaccination in adults in the future.

Treatment of obstructive sleep apnea using a custom-made titratable duobloc oral appliance: a prospective clinical study.

PURPOSE: This prospective clinical study investigates the efficacy of a specific custom-made titratable mandibular advancement device (MAD) for the treatment of obstructive sleep apnea (OSA). This MAD has attachments in the frontal teeth area that allow for progressive titration of the mandible. METHODS: Sixty-one adult OSA patients were included (age, 46.7 ± 9.0 years; male/female ratio, 45/16; apnea-hypopnea index (AHI), 23.2 ± 15.4 events/h sleep; body mass index, 27.9 ± 4.1 kg/m²). After an adaptation period, titration started based on a protocol of symptomatic benefit or upon reaching the physiological limits of protrusion. As a primary outcome, treatment response was defined as an objective reduction in AHI following MAD treatment of ≥50 % compared to baseline, and treatment success as a reduction in AHI with MAD to less than 5 and 10 events/h sleep. Compliance failure was defined as an inability to continue treatment. RESULTS: A statistically significant decrease was observed in AHI, from 23.4 ± 15.7 at baseline to 8.9 ± 8.6 events/h with MAD (p < 0.01). Treatment response was achieved in 42 out of 61 patients (68.8 %), whereas 42.6 % met criteria of AHI < 5 and 63.9 % achieved an AHI < 10 events/h sleep, respectively. Four patients (6.6 %) were considered as "compliance failures." CONCLUSIONS: The present study has evaluated the efficacy of a specific custom-made titratable MAD in terms of sleep apnea reduction.

The European Sleep Apnoea Database (ESADA): report from 22 European sleep laboratories.

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.

Lung function and bronchodilator response in 4-year-old children with different wheezing phenotypes.

Persistent wheeze is a common chronic disease in early childhood and later may progress to asthma. However, the association between pre- and post-bronchodilator lung function and the wheezing phenotype in preschool children is not known. Children 4 yrs of age involved in a prospective birth cohort study (in Antwerp, Belgium) concerning perinatal factors and the occurrence of asthma and allergies, were invited to participate in lung function measurements with the forced oscillation technique. The wheezing phenotype was assessed via (bi)annual questionnaires. Wheezing phenotype and baseline respiratory impedance data were available for 325 children, 96% of whom underwent bronchodilation tests. The baseline resistance at 4 Hz was higher in children with early transient (11.0 hPa x s x L(-1), n = 127) or persistent wheeze (11.9 hPa x s x L(-1), n = 54) than in children who never wheezed (10.3 hPa x s x L(-1), n = 144). After bronchodilation, the resistance decreased on average by 22%. The decrease was greater among the persistent wheezers than among those who never wheezed (3.4 versus 2.3 hPa x s x L( -1)). The baseline lung function was poorer and the bronchodilator response was greater in 4-yr-old children with persistent wheeze than in those who never wheeze or who had early transient wheeze, implying a higher bronchomotor tone in the former group.

Is sleep-disordered breathing an additional risk factor for the metabolic syndrome in obese children and adolescents?

Sleep-disordered breathing is highly prevalent in childhood obesity. Two recent cross-sectional studies have demonstrated an independent association between the severity of sleep-disordered breathing and the metabolic syndrome. A limited number of studies have also addressed the correlation between sleep-disordered breathing and insulin resistance, the core factor of the metabolic syndrome. Cross-sectional reports in modestly obese children are in favor of an association between sleep apnea and insulin resistance. However, these findings were not confirmed in studies of normal-weight children and of morbidly obese children. Only one out of three treatment studies before and after adenotonsillectomy confirmed the association between sleep apnea and insulin resistance, but only in obese children. Although statistical power issues and differences in patient characteristics might partially explain these contradicting results, the evidence to date is far from establishing a causal link between sleep-disordered breathing and insulin resistance. Longitudinal studies and randomized control trials are therefore warranted to investigate a possible causal link between sleep-disordered breathing and insulin resistance.

Medico-legal implications of sleep apnoea syndrome: driving license regulations in Europe.

BACKGROUND: Sleep apnoea syndrome (SAS), one of the main medical causes of excessive daytime sleepiness, has been shown to be a risk factor for traffic accidents. Treating SAS results in a normalized rate of traffic accidents. As part of the COST Action B-26, we looked at driving license regulations, and especially at its medical aspects in the European region. METHODS: We obtained data from Transport Authorities in 25 countries (Austria, AT; Belgium, BE; Czech Republic, CZ; Denmark, DK; Estonia, EE; Finland, FI; France, FR; Germany, DE; Greece, GR; Hungary, HU; Ireland, IE; Italy, IT; Lithuania, LT; Luxembourg, LU; Malta, MT; Netherlands, NL; Norway, EC; Poland, PL; Portugal, PT; Slovakia, SK; Slovenia, SI; Spain, ES; Sweden, SE; Switzerland, CH; United Kingdom, UK). RESULTS: Driving license regulations date from 1997 onwards. Excessive daytime sleepiness is mentioned in nine, whereas sleep apnoea syndrome is mentioned in 10 countries. A patient with untreated sleep apnoea is always considered unfit to drive. To recover the driving capacity, seven countries rely on a physician's medical certificate based on symptom control and compliance with therapy, whereas in two countries it is up to the patient to decide (on his doctor's advice) to drive again. Only FR requires a normalized electroencephalography (EEG)-based Maintenance of Wakefulness Test for professional drivers. Rare conditions (e.g., narcolepsy) are considered a driving safety risk more frequently than sleep apnoea syndrome. CONCLUSION: Despite the available scientific evidence, most countries in Europe do not include sleep apnoea syndrome or excessive daytime sleepiness among the specific medical conditions to be considered when judging whether or not a person is fit to drive. A unified European Directive seems desirable.

Computational fluid dynamics can detect changes in airway resistance in asthmatics after acute bronchodilation.

The effect of a bronchodilator in asthmatics is only partially described by changes in spirometric values since no information on regional differences can be obtained. Imaging techniques like high-resolution computed tomography (HRCT) provide further information but lack detailed information on specific airway responses. The aim of the present study was to improve the actual imaging techniques by subsequent analysis of the imaging data using computational fluid dynamics (CFD). We studied 14 mild to moderately severe asthmatics. Ten patients underwent HRCT before and 4h after inhalation of a novel long acting beta(2) agonist (LABA) that acts shortly after inhalation. Four patients were studied for chronic effects and underwent CT scans twice after adequate wash-out of bronchodilators. In the active group, a significant bronchodilator response was seen with a forced expiratory volume in 1s (FEV1) increase of 8.78 +/- -6.27% pred vs -3.38 +/- 6.87% pred in the control group. The changes in FEV1 correlated significantly with the changes in distal airway volume (r = 0.69, p = 0.007), total airway resistance (r = -0.73, p = 0.003) and distal airway resistance (r = -0.76, p = 0.002) as calculated with the CFD method. The changes in distal R(aw) were not fully homogeneous. In some patients with normal FEV1 at baseline, CFD-based changes in R(aw) were still detectable. We conclude that CFD calculations, based on airway geometries of asthmatic patients, provide additional information about changes in regional R(aw). All changes in the CFD-based calculated R(aw) significantly correlate with the observed changes in spirometric values therefore validating the CFD method for the studied application.

Sleep-disordered breathing and proteinuria in overweight and obese children and adolescents.

OBJECTIVES: To assess whether sleep-disordered breathing (SDB) in overweight children and adolescents has an additional effect on the spectrum of urinary albumin to protein loss, as markers of early kidney dysfunction. METHODS: Prospective study in a clinical sample of overweight children and adolescents. Each subject underwent anthropometry, blood sampling, oral glucose tolerance test and polysomnography. From a 24-hour urine collection, albumin excretion rate and total urinary protein to creatinine ratio (UPCR) were calculated. RESULTS: 94 nondiabetic subjects were included (mean age = 11.0 +/- 2.5, 42 boys). Average BMI z-score was 2.25 +/- 0.47 (26 overweight subjects and 68 obese subjects). There was no difference in albumin excretion rate or UPCR between subjects with and without SDB. None of the SDB parameters correlated with the transformed albumin excretion rate or UPCR. Albumin excretion rate significantly correlated with fasting insulin and C-peptide and with post-challenge glucose, insulin and C-peptide levels, while UPCR correlated with fasting and post-challenge C-peptide levels. Multiple regression indicated that post-challenge glucose levels were the most important predictors of albumin excretion rate. CONCLUSION: Insulin resistance, and not SDB, was associated with increased levels of albuminuria, indicating early renal dysfunction, in this clinical sample of overweight children and adolescents.

Flow analyses in the lower airways: patient-specific model and boundary conditions.

Computational fluid dynamics (CFD) is increasingly applied in the respiratory domain. The ability to simulate the flow through a bifurcating tubular system has increased the insight into the internal flow dynamics and the particular characteristics of respiratory flows such as secondary motions and inertial effects. The next step in the evolution is to apply the technique to patient-specific cases, in order to provide more information about pathological airways. This study presents a patient-specific approach where both the geometry and the boundary conditions (BC) are based on individual imaging methods using computed tomography (CT). The internal flow distribution of a 73-year-old female suffering from chronic obstructive pulmonary disease (COPD) is assessed. The validation is performed through the comparison of lung ventilation with gamma scintigraphy. The results show that in order to obtain agreement within the accuracy limits of the gamma scintigraphy scan, both the patient-specific geometry and the BC (driving pressure) play a crucial role. A minimal invasive test (CT scan) supplied enough information to perform an accurate CFD analysis. In the end it was possible to capture the pathological features of the respiratory system using the imaging and computational fluid dynamics techniques. This brings the introduction of this new technique in the clinical practice one step closer.

Sleep-disordered breathing and the metabolic syndrome in overweight and obese children and adolescents.

OBJECTIVE: To assess whether sleep-disordered breathing (SDB) is a risk factor of the metabolic syndrome (MS) in children and adolescents who are overweight and to examine whether the severity of SDB was independently associated with glucose intolerance, insulin resistance, and/or dyslipidemia. STUDY DESIGN: Consecutive subjects who were overweight or obese underwent polysomnography, fasting blood sample, and oral glucose tolerance test (for calculation of area under the curve [AUC]). SDB was defined as a respiratory disturbance index > or = 2. MS was present when > or = 3 of these factors were present: waist circumference > or = 90th percentile; fasting glucose level > or = 110 mg/dL; triglyceride level > or = 110 mg/dL; high-density lipoprotein cholesterol level < or = 40 mg/dL; blood pressure > or = 90th percentile. RESULTS: A total of 104 subjects were included in the study (44% boys; 58% prepubertal; mean age, 11.1 +/- 2.6 years; 69% obese). Mean SaO2 (odds ratio, 0.54) and SaO2nadir (odds ratio, 0.89) were independent, significant predictors of the presence of MS. Multiple regression showed significant associations between SaO2nadir and high-density lipoprotein cholesterol level, mean SaO2 and both AUC glucose and triglyceride levels, and between the percentage of total sleep time with SaO2 > or = 95% and cholesterol level, while controlling for adiposity and sex, puberty, or both. CONCLUSION: This study supports the hypothesis of an interaction between SDB and metabolic abnormalities, independent of estimates of body fat distribution, in children and adolescents who are overweight and obese.

Reference values for sleep-related respiratory variables in asymptomatic European children and adolescents.

AIM: Only a limited number of studies, designed to establish normal values for sleep-related respiratory variables in children, have been reported, and all are non-European. The aim of this study was to expand the knowledge on normative data in children. METHODS: Subjects ranging from 6 to 16 years were recruited and underwent full polysomnography. Only subjects without sleep disordered breathing or other sleep problems as assessed by clinical history were included. RESULTS: Sixty subjects were studied ( = 11.7 +/- 2.6 years; 28 boys; = 118.8 +/- 30.6%). was 0.85 +/- 1.06 (range: 0.0-5.5). was 0.06 +/- 0.16 (range: 0.0-0.9); 11 patients had a total of 31 obstructive apneas. Only five obstructive hypopneas were detected with = 0.08 +/- 0.17 (range: 0.0-0.9). was 1.98 +/- 1.39 (range: 0.1-7.2). was 97.0 +/- 0.6% (range: 96.0-98.0); was 91.8 +/- 2.7% (range: 82.0-96.0); <% of total sleep time with SaO2 >or= 95%> was 98.7 +/- 2.1% (range: 90.8-100.0); was 0.8 +/- 0.9 (range: 0.0-4.9) and was 6.1 +/- 1.8 (range: 2.7-10.9). Snoring was detected in 15 patients (4 overweight subjects), with no difference in patient characteristics and sleep-related respiratory variables between snorers and non-snorers. Subjects in the overweight group (n = 22) had a lower SaO2nadir (90.8 +/- 2.7 vs. 92.4 +/- 2.6; P = 0.01) and a higher ODI (1.3 +/- 1.3 vs. 0.4 +/- 0.4; P = 0.0002) than their normal weight peers. CONCLUSION: Our data are in agreement with other non-European studies, designed to establish normal values in children.

Is wheezing associated with decreased sleep quality in Sri Lankan children? A questionnaire study.

AIM: To investigate the association between wheezing and impaired sleep in Sri Lankan children, aged 6-12 years; and, to report the prevalence of asthma-related symptoms in these subjects. METHODS: The International Study of Asthma and Allergies in Childhood questionnaire and a separate sleep questionnaire were completed. RESULTS: Of 800 originally distributed questionnaires, 652 were analyzed. Wheezing was present in 89 children (14%). Within this group, 66% reported wheezing in the last 12 months. Wheezing children had a significantly higher presence of snoring, restless sleep, nocturnal awakenings and daytime tiredness. Wheezing was found to be independently associated with restless sleep (odds ratio (OR) = 2.4). There was no association between wheezing and difficulties falling asleep, nocturnal awakenings, apneas, and daytime sleepiness and tiredness. After adjusting for possible confounders, the following significant associations were present: snoring and apneas (OR = 1.6), chronic rhinitis and apneas (OR = 1.6), snoring and restless sleep (OR = 3.2), chronic rhinitis and restless sleep (OR = 2.1), and hayfever and daytime tiredness (OR = 4.3). Wheezing was related to an increased risk of snoring (OR = 2.8) and subjects with chronic rhinitis had also an increased risk of snoring (OR = 1.7), adjusting for possible confounders. CONCLUSION: The sleep of wheezing children was impaired compared with their non-wheezing peers, resulting in an increased prevalence of daytime tiredness. Upper airway symptoms, such as chronic rhinitis or hayfever, should be carefully considered in these children, as they might be responsible for these sleep problems.

Glucocorticosteroids as antioxidants in treatment of asthma and COPD. New application for an old medication?

Inhaled corticosteroids (ICS) are the standard of care in asthma and are widely used in the treatment of patients with COPD. The influence of steroids on inflammatory processes has long been established since glucocorticoids and their receptor belong to the regulatory network involved in inhibition of several inflammatory pathways. Inflammatory processes are usually accompanied by an increased oxidative burden followed by a depletion of antioxidants. Therefore, the effects of steroids on antioxidant status have been investigated revealing possible positive effects on the reduced antioxidant enzyme activity. Nevertheless, the mechanisms of this modulation have not been fully elucidated yet. It is possible that antioxidant enzyme activity is regulated at the level of transcription. Additionally, because of the fact that antioxidant enzymes are trace element dependent, steroids may affect their activity through influence on trace element accumulation. This review summarizes the effects of steroids on the antioxidant enzymes activity in vitro and in vivo in relation to asthma and COPD.

Correlation between severity of sleep apnea and upper airway morphology based on advanced anatomical and functional imaging.

Determination of the apnea hypopnea index (AHI) as a measure of the severity of obstructive sleep apnea/hypopnea syndrome (OSAHS) is a widely accepted methodology. However, the outcome of such a determination depends on the method used, is time consuming and insufficient for prediction of the effect of all treatment modalities. For these reasons more methods for evaluating the severity of OSAHS, based on different imaging modalities, have been looked into and recent studies have shown that anatomical properties determined from three-dimensional (3D) computed tomography (CT) images are good markers for the severity of the OSAHS. Therefore, we correlated anatomical measurements of a 3D reconstruction of the upper airway together with flow simulation results with the severity of OSAHS in order to find a combination of variables to indicate the severity of OSAHS in patients. The AHI of 20 non-selected, consecutive patients has been determined during a polysomnography. All patients also underwent a CT scan from which a 3D model of the upper airway geometry was reconstructed. This 3D model was used to evaluate the anatomical properties of the upper airway in OSAHS patients as well as to perform computational fluid dynamics (CFD) computations to evaluate the airflow and resistance of this upper airway. It has been shown that a combination of the smallest cross-sectional area and the resistance together with the body mass index (BMI) form a set of markers that predict very well the severity of OSAHS in patients within this study. We believe that these markers can be used to evaluate the outcome of an OSAHS treatment.

Functional imaging using computational fluid dynamics to predict treatment success of mandibular advancement devices in sleep-disordered breathing.

Mandibular advancement devices (MADs) have emerged as a popular alternative for the treatment of sleep-disordered breathing. These devices bring the mandibula forward in order to increase upper airway (UA) volume and prevent total UA collapse during sleep. However, the precise mechanism of action appears to be quite complex and is not yet completely understood; this might explain interindividual variation in treatment success. We examined whether an UA model, that combines imaging techniques and computational fluid dynamics (CFD), allows for a prediction of the treatment outcome with MADs. Ten patients that were treated with a custom-made mandibular advancement device (MAD), underwent split-night polysomnography. The morning after the sleep study, a low radiation dose CT scan was scheduled with and without the MAD. The CT examinations allowed for a comparison between the change in UA volume and the anatomical characteristics through the conversion to three-dimensional computer models. Furthermore, the change in UA resistance could be calculated through flow simulations with CFD. Boundary conditions for the model such as mass flow rate and pressure distributions were obtained during the split-night polysomnography. Therefore, the flow modeling was based on a patient specific geometry and patient specific boundary conditions. The results indicated that a decrease in UA resistance and an increase in UA volume correlate with both a clinical and an objective improvement. The results of this pilot study suggest that the outcome of MAD treatment can be predicted using the described UA model.

Assessment of lung deposition and analysis of the effect of fluticasone/salmeterol hydrofluoroalkane (HFA) pressurized metered dose inhaler (pMDI) in stable persistent asthma patients using functional respiratory imaging.

BACKGROUND: Unambiguously for inhaled products, PK measures are best suited for ensuring that the total systemic exposure is equivalent for two products but cannot provide regional information about lung deposition and structural changes. Functional respiratory imaging (FRI) has been demonstrated to be sensitive for distinguishing small but imperative differences related to a single treatment. METHODS: In this study FRI is used in 16 asthmatic patients to assess equivalence in regional deposition for two products (fluticasone/salmeterol, test and reference) by directly measuring regional functional and structural changes within the lungs following its administration. RESULTS: No differences were observed between the lung deposition patterns and the effects on lung structure and function of two products, having the same formulation and manufactured by different organizations using FRI. CONCLUSIONS: Results using FRI complement PK assessments. The added value of this approach to the conventional clinical methods could be significant.