Bernardo J. Selim

Obstructive sleep apnea as a risk factor for type 2 diabetes.

PURPOSE Cross-sectional studies have documented the co-occurrence of obstructive sleep apnea (hereafter, sleep apnea) with glucose intolerance, insulin resistance, and type 2 diabetes mellitus (hereafter, diabetes). It has not been determined, however, whether sleep apnea is independently associated with the subsequent development of diabetes, accounting for established risk factors. METHODS This observational cohort study examined 1233 consecutive patients in the Veteran Affairs Connecticut Healthcare System referred for evaluation of sleep-disordered breathing; 544 study participants were free of preexisting diabetes and completed a full, attended, diagnostic polysomnogram. The study population was divided into quartiles based on severity of sleep apnea as measured by the apnea-hypopnea index. The main outcome was incident diabetes defined as fasting glucose level >126 mg/dL and a corresponding physician diagnosis. Compliance with positive airway pressure therapy, and its impact on the main outcome, also was examined. RESULTS In unadjusted analysis, increasing severity of sleep apnea was associated with an increased risk of diabetes (P for linear trend <.001). After adjusting for age, sex, race, baseline fasting blood glucose, body mass index, and weight change, an independent association was found between sleep apnea and incident diabetes (hazard ratio per quartile 1.43; confidence interval 1.10-1.86). Among patients with more severe sleep apnea (upper 2 quartiles of severity), 60% had evidence of regular positive airway pressure use, and this treatment was associated with an attenuation of the risk of diabetes (log-rank test P=.04). CONCLUSION Sleep apnea increases the risk of developing diabetes, independent of other risk factors. Among patients with more severe sleep apnea, regular positive airway pressure use may attenuate this risk.

Cardiovascular Consequences of Sleep Apnea

Cardiovascular disease has been the leading cause of death since 1900. Strategies for cardiovascular disease and prevention have helped to reduce the burden of disease, but it remains an important public health challenge. Therefore, understanding the underlying pathophysiology and developing novel therapeutic approaches for cardiovascular disease is of crucial importance. Recognizing the link between sleep and cardiovascular disease may represent one such novel approach. Obstructive sleep apnea (OSA), a common form of sleep-disordered breathing, has a high and rising prevalence in the general adult population, attributable in part to the emerging epidemic of obesity and enhanced awareness. OSA has been independently linked to specific cardiovascular outcomes such as hypertension, stroke, myocardial ischemia, arrhythmias, fatal and nonfatal cardiovascular events, and all-cause mortality. Treatment of OSA may represent a novel target to reduce cardiovascular health outcomes.

The health status of elderly veteran enrollees in the Veterans Health Administration

Objectives: To examine the health status of elderly veteran enrollees, stratified by age group, and compare with nonveteran populations.

Risk-adjusted mortality as an indicator of outcomes: comparison of the Medicare Advantage Program with the Veterans' Health Administration.

Background:The Medicare Advantage Program (MAP) and the Veterans’ Health Administration (VHA) currently provide many services that benefit the elderly, and a comparative study of their risk-adjusted mortality rates has the potential to provide important information regarding these 2 systems of care. Objective:The objective of this retrospective study was to compare mortality rates between the MAP and the VHA after controlling for case-mix differences. Subjects:This study consisted of 584,294 MAP patients and 420,514 VHA patients. Measures:We used the Death Master File to ascertain the vital status of each study subject over approximately 4 years. We used Cox regression models to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for the MAP compared with VHA patients. Results:The average age for male MAP patients was 73.8 years (±5.6) and for male VHA patients was 74.05 years (±6.3). Unadjusted mortality rates of males for VHA and MAP were 25.7% and 22.8%, respectively, over approximately 4 years (P < 0.0001), respectively. The case-mix of VHA patients, however, was sicker than those from MAP. After adjusting for case-mix, the HR for mortality in the MAP was significantly higher than that in the VHA (HR, 1.404; 95% CI = 1.383–1.426). We obtained similar results when we compared the mortality rates of females for VHA and MAP. Conclusions:After adjusting for their higher prevalence of chronic disease and worse self-reported health, mortality rates were lower for patients cared for in the VHA compared with those in the MAP. Further studies should examine what differences in care structures and processes contribute to lower mortality in the VHA.

Therapy for Sleep Hypoventilation and Central Apnea Syndromes

Opinion statement• Primary Central Sleep Apnea (CSA): We would recommend a trial of Positive Airway Pressure (PAP), acetazolamide, or zolpidem based on thorough consideration of risks and benefits and incorporation of patient preferences.• Central Sleep Apnea Due to Cheyne-Stokes Breathing Pattern in Congestive Heart Failure (CSR-CHF): We would recommend PAP devices such as continuous positive airway pressure (CPAP) or adaptive servo-ventilation (ASV) to normalize sleep-disordered breathing after optimizing treatment of heart failure. Oxygen may also be an effective therapy. Acetazolamide and theophylline may be considered if PAP or oxygen is not effective.• Central Sleep Apnea due to High-Altitude Periodic Breathing: We would recommend descent from altitude or supplemental oxygen. Acetazolamide may be used when descent or oxygen are not feasible, or in preparation for ascent to high altitude. Slow ascent may be preventative.• Central Sleep Apnea due to Drug or Substance: If discontinuation or reduction of opiate dose is not feasible or effective, we would recommend a trial of CPAP, and if not successful, treatment with ASV. If ASV is ineffective or if nocturnal hypercapnia develops, bilevel positive airway pressure-spontaneous timed mode (BPAP-ST) is recommended.• Obesity hypoventilation syndrome: We would recommend an initial CPAP trial. If hypoxia or hypercapnia persists on CPAP, BPAP, BPAP-ST or average volume assured pressure support (AVAPS™) is recommended. Tracheostomy with nocturnal ventilation should be considered when the above measures are not effective. Weight loss may be curative.• Neuromuscular or chest wall disease: We would recommend early implementation of BPAP-ST based on thorough consideration of risks and benefits and patient preferences. AVAPS™ may also be considered. We recommend close follow up due to disease progression.

Comparison of Health Outcomes for Male Seniors in the Veterans Health Administration and Medicare Advantage Plans

OBJECTIVES To compare the Veterans Health Administration (VHA) with the Medicare Advantage (MA) plans with regard to health outcomes. DATA SOURCES The Medicare Health Outcome Survey, the 1999 Large Health Survey of Veteran Enrollees, and the Ambulatory Care Survey of Healthcare Experiences of Patients (Fiscal Years 2002 and 2003). STUDY DESIGN A retrospective study. EXTRACTION METHODS Men 65+ receiving care in MA (N=198,421) or in VHA (N=360,316). We compared the risk-adjusted probability of being alive with the same or better physical (PCS) and mental (MCS) health at 2-years follow-up. We computed hazard ratio (HR) for 2-year mortality. PRINCIPAL FINDINGS Veterans had a higher adjusted probability of being alive with the same or better PCS compared with MA participants (VHA 69.2 versus MA 63.6 percent, p<.001). VHA patients had a higher adjusted probability than MA patients of being alive with the same or better MCS (76.1 versus 69.6 percent, p<.001). The HRs for mortality in the MA were higher than in the VHA (HR, 1.26 [95 percent CI 1.23-1.29]). CONCLUSIONS Our findings indicate that the VHA has better patient outcomes than the private managed care plans in Medicare. The VHAs performance offers encouragement that the public sector can both finance and provide exemplary health care.

Polysomnographic phenotypes and their cardiovascular implications in obstructive sleep apnoea

Background Obstructive sleep apnoea (OSA) is a heterogeneous disorder, and improved understanding of physiologic phenotypes and their clinical implications is needed. We aimed to determine whether routine polysomnographic data can be used to identify OSA phenotypes (clusters) and to assess the associations between the phenotypes and cardiovascular outcomes. Methods Cross-sectional and longitudinal analyses of a multisite, observational US Veteran (n=1247) cohort were performed. Principal components-based clustering was used to identify polysomnographic features in OSA’s four pathophysiological domains (sleep architecture disturbance, autonomic dysregulation, breathing disturbance and hypoxia). Using these features, OSA phenotypes were identified by cluster analysis (K-means). Cox survival analysis was used to evaluate longitudinal relationships between clusters and the combined outcome of incident transient ischaemic attack, stroke, acute coronary syndrome or death. Results Seven patient clusters were identified based on distinguishing polysomnographic features: ‘mild’, ‘periodic limb movements of sleep (PLMS)’, ‘NREM and arousal’, ‘REM and hypoxia’, ‘hypopnoea and hypoxia’, ‘arousal and poor sleep’ and ‘combined severe’. In adjusted analyses, the risk (compared with ‘mild’) of the combined outcome (HR (95% CI)) was significantly increased for ‘PLMS’, (2.02 (1.32 to 3.08)), ‘hypopnoea and hypoxia’ (1.74 (1.02 to 2.99)) and ‘combined severe’ (1.69 (1.09 to 2.62)). Conventional apnoea–hypopnoea index (AHI) severity categories of moderate (15≤AHI<30) and severe (AHI ≥30), compared with mild/none category (AHI <15), were not associated with increased risk. Conclusions Among patients referred for OSA evaluation, routine polysomnographic data can identify physiological phenotypes that capture risk of adverse cardiovascular outcomes otherwise missed by conventional OSA severity classification.

Quality measures for the care of patients with narcolepsy.

ABSTRACT The American Academy of Sleep Medicine (AASM) commissioned a Workgroup to develop quality measures for the care of patients with narcolepsy. Following a comprehensive literature search, 306 publications were found addressing quality care or measures. Strength of association was graded between proposed process measures and desired outcomes. Following the AASM process for quality measure development, we identified three outcomes (including one outcome measure) and seven process measures. The first desired outcome was to reduce excessive daytime sleepiness by employing two process measures: quantifying sleepiness and initiating treatment. The second outcome was to improve the accuracy of diagnosis by employing the two process measures: completing both a comprehensive sleep history and an objective sleep assessment. The third outcome was to reduce adverse events through three steps: ensuring treatment follow-up, documenting medical comorbidities, and documenting safety measures counseling. All narcolepsy measures described in this report were developed by the Narcolepsy Quality Measures Work-group and approved by the AASM Quality Measures Task Force and the AASM Board of Directors. The AASM recommends the use of these measures as part of quality improvement programs that will enhance the ability to improve care for patients with narcolepsy.

The Association between Nocturnal Cardiac Arrhythmias and Sleep-Disordered Breathing: The DREAM Study.

STUDY OBJECTIVES To determine whether sleep-disordered breathing (SDB) is associated with cardiac arrhythmia in a clinic-based population with multiple cardiovascular comorbidities and severe SDB. METHODS This was a cross-sectional analysis of 697 veterans who underwent polysomnography for suspected SDB. SDB was categorized according to the apnea-hypopnea index (AHI): none (AHI < 5), mild (5 ≥ AHI < 15), and moderate-severe (AHI ≥ 15). Nocturnal cardiac arrhythmias consisted of: (1) complex ventricular ectopy, (CVE: non-sustained ventricular tachycardia, bigeminy, trigeminy, or quadrigeminy), (2) combined supraventricular tachycardia, (CST: atrial fibrillation or supraventricular tachycardia), (3) intraventricular conduction delay (ICD), (4) tachyarrhythmias (ventricular and supraventricular), and (5) any cardiac arrhythmia. Unadjusted, adjusted logistic regression, and Cochran-Armitage testing examined the association between SDB and cardiac arrhythmias. Linear regression models explored the association between hypoxia, arousals, and cardiac arrhythmias. RESULTS Compared to those without SDB, patients with moderate-severe SDB had almost three-fold unadjusted odds of any cardiac arrhythmia (2.94; CI 95%, 2.01-4.30; p < 0.0001), two-fold odds of tachyarrhythmias (2.16; CI 95%,1.47-3.18; p = 0.0011), two-fold odds of CVE (2.01; 1.36-2.96; p = 0.003), and two-fold odds of ICD (2.50; 1.58-3.95; p = 0.001). A linear trend was identified between SDB severity and all cardiac arrhythmia subtypes (p value linear trend < 0.0001). After adjusting for age, BMI, gender, and cardiovascular diseases, moderate-severe SDB patients had twice the odds of having nocturnal cardiac arrhythmias (2.24; 1.48-3.39; p = 0.004). Frequency of obstructive respiratory events and hypoxia were strong predictors of arrhythmia risk. CONCLUSIONS SDB is independently associated with nocturnal cardiac arrhythmias. Increasing severity of SDB was associated with an increasing risk for any cardiac arrhythmia.

Differences in risk-adjusted mortality between medicaid-eligible patients enrolled in medicare advantage plans and those enrolled in the veterans health administration.

BackgroundWe compared risk-adjusted mortality rates between Medicaid-eligible patients in the Medicare Advantage plans (“MA dual enrollees”) and Medicaid-eligible patients in the Veterans Health Administration (“VHA dual enrollees”). MethodsWe used the Death Master File to ascertain the vital status of 1912 MA and 2361 VHA dual enrollees. We used Cox regression models to estimate hazard ratios (HRs) with 95% confidence intervals (CIs). ResultsThe 3-year mortality rates of VHA and MA dual enrollees were 15.8% and 19.0%, respectively. The adjusted HR of mortality in the MA dual enrollees was significantly higher than in the VHA dual enrollees (HR, 1.260 [95% CI, 1.044–1.520]). This was also the case for elderly patients and those from racial/ethnic minority groups. ConclusionsThe VHA had better health outcomes than did MA plans. The VHAs performance is reassuring, given its emphasis on equal access to healthcare in an environment that is less dependent on patient financial considerations.