Update in sleep medicine 2012

Atherosclerotic plaque in individuals without known cardiovascular disease but with established obstructive sleep apnea and at high risk of obstructive sleep apnea

Objectives

In a large U.S. cohort free of CVD evaluated by coronary computed CT angiography, we aimed to assess the association between established / high risk of Obstructive Sleep Apnea (OSA) and coronary plaque.

Background

There are limited data available depicting the association between established / high risk of OSA and the presence of coronary plaque in a population-based sample free from CVD.

Methods

Cross-sectional data from 2359 participants enrolled in the Miami Heart Study (MiHeart) who underwent coronary CT angiography was used for this study. The Berlin questionnaire was used to stratify patients as having high or low risk of OSA. Multiple multivariable logistic regression analyses were conducted to investigate the association between the risk of developing OSA with the presence, volume, and composition of plaque.

Results

According to the Berlin questionnaire, 1559 participants were (66.1%) at low risk of OSA and 800 patients (33.9%) with established / high risk of OSA. Plaque characterization on CCTA revealed a greater incidence of any possible plaque composition in the established / high risk of OSA category (59.6% vs. 43.5%) compared to the low risk of OSA cohort. In logistic regression models, after adjusting for demographics and cardiovascular risk factors, a significant association could still be noted between established / high risk of OSA and any coronary plaque on CCTA (OR=1.31, CI 1.05, 1.63, p = 0.016). Subgroup analysis in the Hispanic population also portrayed a significant association between established / high risk of OSA and the presence of coronary plaque on CCTA (OR = 1.55 CI 1.13, 2.12, p = 0.007).

Conclusion

After accounting for CVD risk factors, individuals at established / high risk of OSA have a higher likelihood of the presence of coronary plaque. Future studies should focus on OSA presence or risk, OSA severity, and the longitudinal consequences of coronary atherosclerosis.

Research Priorities in Pathophysiology for Sleep-disordered Breathing in Patients with Chronic Obstructive Pulmonary Disease. An Official American Thoracic Society Research Statement

BACKGROUND

Obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD) are common conditions; the co-occurrence of these diseases, called the overlap syndrome (OVS), has been associated with poor health outcomes.

PURPOSE

The purpose of this Official American Thoracic Society Research Statement is to describe pathophysiology, epidemiology, outcomes, diagnostic metrics, and treatment of OVS, as well as to identify important gaps in knowledge and make recommendations for future research.

METHODS

Clinicians and researchers with expertise in sleep medicine, pulmonary medicine, or both were invited to participate. Topics were divided among the participants according to their interest and expertise. A literature search was conducted; the search was not a formal systematic review. Evidence was considered and supplemented with the panelists' nonsystematic clinical observations. Important knowledge gaps were identified.

RESULTS

Recommendations for research to fill existing knowledge gaps were made. The recommendations were formulated by discussion and consensus.

CONCLUSIONS

Many important questions about OVS exist. This American Thoracic Society Research Statement highlights the types of research that leading clinicians and researchers believe will have the greatest impact on better understanding the spectrum of disease, improving diagnosis, and optimizing therapy.

Sleep apnea, metabolic disease, and the cutting edge of therapy

Obstructive sleep apnea (OSA) is common, and many cross-sectional and longitudinal studies have established OSA as an independent risk factor for the development of a variety of adverse metabolic disease states, including hypertension, insulin resistance, type 2 diabetes, nonalcoholic fatty liver disease, dyslipidemia, and atherosclerosis. Nasal continuous positive airway pressure (CPAP) has long been the mainstay of therapy for OSA, but definitive studies demonstrating the efficacy of CPAP in improving metabolic outcomes, or in reducing incident disease burden, are lacking; moreover, CPAP has variable rates of adherence. Therefore, the future of OSA management, particularly with respect to limiting OSA-related metabolic dysfunction, likely lies in a coming wave of alternative approaches to endophenotyping OSA patients, personalized care, and defining and targeting mechanisms of OSA-induced adverse health outcomes.

Association of Obstructive Sleep Apnea With Subclinical Cardiovascular Disease Predicted by Coronary Artery Calcium Score in Asymptomatic Subjects

The aim of this study is to determine the association among various sleep parameters for obstructive sleep apnea (OSA) and subclinical cardiovascular disease measured by coronary artery calcium (CAC) score. A cross-sectional study was conducted among 461 patients who underwent both polysomnography (PSG) and coronary artery computed tomography to evaluate CAC score. For each participant, coronary artery computed tomography was conducted within 12 months of PSG. We evaluated the possible association among various PSG parameters by evaluating overnight-attended PSG and CAC. A univariate analysis with lowest SaO₂ and stage 3 sleep % during sleep was significantly associated with CAC score (β = -5.528, 95% confidence interval [CI] -9.179 to -1.777, p = 0.004 and β = -8.658, 95% CI -16.461 to -0.855, p = 0.030, respectively). However, after adjustment for possible confounders, only the lowest SaO₂ was independently associated with CAC score (β = -5.234, 95% CI -9.215 to -1.253, p = 0.010). This association was stronger in participants aged ≥60 years (β = -26.966, 95% CI -41.874 to -12.058, p = 0.001). In a univariate analysis, apnea-hypopnea index, stage 3 sleep %, and moderate and severe OSA were significantly associated with CAC presence (odds ratio [OR] 1.010, p = 0.035; OR 0.949, p = 0.039; OR 2.186, p = 0.013; and OR 2.019, p = 0.020, respectively). However, after adjusting for possible confounders, there was no significant association. In conclusion, the patients with intermittent hypoxemia during sleep should be considered for evaluation of coronary artery calcification to detect cardiovascular disease in subclinical status.

Should All Congestive Heart Failure Patients Have a Routine Sleep Apnea Screening? Con

Sleep-disordered breathing (SDB) is one of the most common comorbidities in people with congestive heart failure (CHF). Although SDB has major cardiometabolic consequences, the attributable risk of SDB in asymptomatic CHF patients remains unclear. Whether early intervention using positive airway pressure would improve the prognosis in CHF patients is uncertain. As yet, there is insufficient evidence that routine polysomnography screening is cost-effective for asymptomatic CHF patients. Careful clinical risk evaluation and thoughtful use of limited-channel home sleep testing should be considered before the application of routine polysomnography in all CHF patients.

On the cutting edge of obstructive sleep apnoea: where next?

Obstructive sleep apnoea is a common disease that is now more widely recognised because of the rise in prevalence and the increasingly compelling data that shows major neurocognitive and cardiovascular sequelae. At the same time, the clinical practice of sleep medicine is changing rapidly, with novel diagnostics and treatments that have established a home-based (rather than laboratory-based) management approach. We review the most recent insights and discoveries in obstructive sleep apnoea, with a focus on diagnostics and therapeutics. As will be discussed, management of obstructive sleep apnoea could soon transition from a so-called one size fits all approach to an individualised approach.