Sleep apnea cardiovascular clinical trials - current status and steps forward: the International Collaboration of Sleep Apnea Cardiovascular Trialists

Sleep apnea is a common chronic disease that is associated with coronary heart disease, stroke, heart failure and mortality, although the ability of sleep apnea treatment to reduce cardiovascular morbidity and mortality has not been demonstrated. In contrast to patients seeking treatment in sleep disorders centers, as many as half of individuals with moderate to severe sleep apnea in the general population do not report excessive sleepiness; however, if treatment of sleep apnea were shown to reduce cardiovascular disease risk, this would provide a strong rationale for treatment of sleep apnea even in the absence of daytime sleepiness. This article summarizes the status of clinical trials evaluating the potential cardiovascular benefits of sleep apnea treatment and discusses the challenges of conducting such trials, and introduces the International Collaboration of Sleep Apnea Cardiovascular Trialists (INCOSACT), a clinical research collaboration formed to foster cardiovascular sleep research.Australian National Health and Medical Research Counci

Inflammatory Markers and Obstructive Sleep Apnea in Obese Children: The NANOS Study

Introduction: Obesity and obstructive sleep apnea syndrome (OSA) are common coexisting conditions associated with a chronic low-grade inflammatory state underlying some of the cognitive, metabolic, and cardiovascular morbidities. Aim: To examine the levels of inflammatory markers in obese community-dwelling children with OSA, as compared to no-OSA, and their association with clinical and polysomnographic (PSG) variables. Methods. In this cross-sectional, prospective multicenter study, healthy obese Spanish children (ages 4-15 years) were randomly selected and underwent nocturnal PSG followed by a morning fasting blood draw. Plasma samples were assayed for multiple inflammatory markers. Results: 204 children were enrolled in the study; 75 had OSA, defined by an obstructive respiratory disturbance index (RDI) of 3 events/hour total sleep time (TST). BMI, gender, and age were similar in OSA and no-OSA children. Monocyte chemoattractant protein-1 (MCP-1) and plasminogen activator inhibitor-1 (PAI-1) levels were significantly higher in OSA children, with interleukin-6 concentrations being higher in moderate-severe OSA (i.e., AHI > 5/hrTST; P < 0.01), while MCP-1 levels were associated with more prolonged nocturnal hypercapnia (P < 0.001). Conclusion: IL-6, MCP-1, and PAI-1 are altered in the context of OSA among community-based obese children further reinforcing the proinflammatory effects of sleep disorders such as OSA. This trial is registered with ClinicalTrials.gov NCT01322763

Treatment outcomes of obstructive sleep apnoea in obese community-dwelling children: the NANOS study

The first line of treatment of obstructive sleep apnoea syndrome (OSAS) in children consists of adenotonsillectomy (T&A). The aim of the present study was to evaluate treatment outcomes of OSAS among obese children recruited from the community.A cross-sectional, prospective, multicentre study of Spanish obese children aged 3-14 years, with four groups available for follow-up: group 1: non-OSAS with no treatment; group 2: dietary treatment; group 3: surgical treatment; and group 4: continuous positive airway pressure treatment.117 obese children (60 boys, 57 girls) with a mean age of 11.3±2.9 years completed the initial (T0) and follow-up (T1) assessments. Their mean body mass index (BMI) at T1 was 27.6±4.7 kg·m(-2), corresponding to a BMI Z-score of 1.34±0.59. Mean respiratory disturbance index (RDI) at follow-up was 3.3±3.9 events·h(-1). Among group 1 children, 21.2% had an RDI ?3 events·h(-1) at T1, the latter being present in 50% of group 2, and 43.5% in group 3. In the binary logistic regression model, age emerged as a significant risk factor for residual OSAS (odds ratio 1.49, 95% confidence interval 1.01-2.23; p<0.05) in obese children surgically treated, and RDI at T0 as well as an increase in BMI emerged as significant risk factors for persistent OSAS in obese children with dietary treatment (OR 1.82, 95% CI 1.09-3.02 (p<0.03) and OR 8.71, 95% CI 1.24-61.17 (p=0.03)).Age, RDI at diagnosis and obesity are risk factors for relatively unfavourable OSAS treatment outcomes at follow-up

Metabolic biomarkers in community obese children: effect of obstructive sleep apnea and its treatment

Objective: Obesity and obstructive sleep apnea in children have been associated with metabolic morbidities. The present study aimed to evaluate the presence of metabolic alterations among obese children recruited from the community, with and without obstructive sleep apnea syndrome (OSAS), and the impact of treatment of OSAS on metabolic profiles. Methods: A cross-sectional, prospective, multicenter study of Spanish children aged 3-14 years with a body mass index (BMI) ?95th percentile for age and sex were randomly selected in the first phase. Four groups emerged for follow-up: (1) no treatment; (2) dietary intervention; (3) surgical treatment of OSA; and (4) continuous positive airway pressure (CPAP) treatment of OSA. Fasting blood tests were performed at baseline (T0) and approximately one year after the intervention (T1). Results: A total of 113 obese children with a mean age of 11.3 ± 2.9 years completed T0 and T1 assessments. Their mean BMI z-score at T1 was 1.34 ± 0.59, and mean Respiratory Disturbance Index was 8.6 ± 13.0 at T0 and 3.3 ± 4.0/hour total sleep time at T1. Only glucose fasting levels differed among metabolic parameters in obese children with OSAS and without OSAS at baseline (T0) (p = 0.018). There were statistically significant differences between surgically treated OSAS (p = 0.002), and CPAP-treated OSAS (p = 0.024) versus the non-OSAS group in the glucose levels between baseline (T0) and follow-up (T1) after controlling for age and change in BMI. Significant univariate associations between BMI and C-reactive protein, insulin, and homeostasis model assessment of insulin resistance emerged at both T0 and T1. Conclusions: Concurrent obesity and OSAS could promote metabolic and inflammatory alterations, and the latter appeared to be sensitive to OSAS treatment outcomes. ClinicalTrials.gov Identifier: NCT01322763

A visit to Absurdistan: A nightmare of a sleep specialist

During a nocturnal dream, the authors discover a strange and unknown country, Absurdistan. Absurdistanis main concern appears to be sleep, whether nocturnal or diurnal, rather than wakefulness. They are fond of sleeping in any form, and devote much time to this activity. The authors follow a guide that shows them all kinds of strange sleep habits and keeps explaining the complex as well as the obvious. As the journey evolves, the explanations turn more and more confusing, becoming also amazingly surrealistic. The dream ends with a welcome wakefulness leaving the authors unsure of which is the waking state and which the dream. © 2013 Elsevier Ltd

Predicting the night-to-night variability in the severity of obstructive sleep apnea: the case of the standard error of measurement

Study objectives: Night-to-night variability in the apnea-hypopnea index (AHI) may affect the accuracy of the diagnosis of obstructive sleep apnea (OSA) and treatment selection. This study was conducted to assess the utility of the standard error of measurement (SEM) in predicting the night-to-night variability in the OSA. Methods: Ninety nine patients underwent a 3-consecutive nights of sleep monitoring with a validated home portable monitoring devise (BTI-APNiA, BTI Biotechnology Institute, Vitoria, Spain). The night-to-night variability in apnea- and hypopnea-related measures and blood desaturation were assessed. The agreement between the three nights was also assessed. The SEM and the AHI of the first night were used to calculate a range for the severity of the OSA. This range was then challenged to predict the most frequent OSA severity, the OSA severity in nights 2 and 3, and the OSA severity in the three nights. Results: Ninety nine patients (mean age: 56±14 years) participated in the study. The mean body mass index was 25.4±4.0 Kg/m2 and the mean score of Epworth questionnaire was 8±5. The AHI of the first, second and third nights were 13.96±13.46, 13.76±12.76 and 13.52±12.91 events/h, respectively. The night-to-night variability in the AHI and the sleep time in supine position over the three nights were not statistically significant. However, the differences in the severity of the OSA was statistically significant (range of agreement in the diagnosis: 41.7%- 83.3%). The standard error of measurement (SEM) considering the AHI was 4.64 events/h.. The SEM was efficient in predicting the most frequent OSA severity (among the three nights) in more than 96% of the cases. Conclusions: The night-to-night variability in the AHI might affect the diagnosis of OSA. The use of standard error of measurement and the AHI of one single night would be of interest to predict the night-to-night variability in the severity of OSA