COPD, Sleep Apnea, and Asthma: American Thoracic Society Conference Highlights

May 9, 2012

Among the information of interest to primary care: Asymptomatic smokers may show signs of COPD, and what to do about it. How to treat obstructive sleep apnea as effectively as a sleep center. And things you may not know about inhalers.

The annual American Thoracic Society (ATS) meeting, which begins May 18 in San Francisco,  may be one of the largest gatherings of pulmonary, critical care, and sleep specialists in the world (more than 13,000 are expected this year). But several of the tracks directly affect primary care physicians: COPD, asthma, and sleep apnea. We’ve gone through the 5,800 abstracts and culled several we think will interest you.

Click on the links below to read about the topics:

Chronic Obstructive Pulmonary Disorder (COPD) at ATS
    CAT testing and smokers
    CAT and exacerbations
    Screening for COPD
    Dyspnea in COPD
    Fatigue

Sleep Apnea at ATS
    Cardiometabolic disorders and obstructive sleep apnea (OSA)
    OSA treatment in the primary care setting
    OSA and COPD

Asthma at ATS
    Early introduction of solid food and asthma risk
    Obesity and asthma
    Inhaler techniques

You can find all the abstracts at the ATS meeting web site.
 

Chronic Obstructive Pulmonary Disorder (COPD) at ATS

The most recent updated guidelines from the Global Strategy for the Diagnosis, Management, and Prevention (GOLD), issued in December 2011, recommend that clinicians incorporate symptom assessment tools into their decision making regarding treatment. Specifically, they advise using the COPD Assessment Test (CAT) every 2 to 3 months to identify “trends and changes,” rather than relying only on annual spirometry. The goal is to focus on improving quality of life, not just symptoms; the two do not always correlate. 

The higher the score on the 8-item CAT test, the worse the patient’s quality of life. Patients can even take the test online (http://www.catestonline.org/english/indexEN.htm) and bring it with them for their appointments. Tracking the score over time can provide insight into how quickly the disease is progressing. A change of 2 points is considered clinically relevant. Scores below 10 are considered low; 10-20, medium; 21-30, high; and greater than 30, very high, with specific management options recommended in each category.1
 
Several presentations at ATS will document how clearly the CAT test indicates function and quality of life among COPD patients, some of whom don’t even show symptoms. A number of the abstracts have implications for the way COPD is treated.

CAT testing in smokers.  In one study, researchers gave the CAT to 342 heavy smokers, 68% of them currently smokers. None had yet been diagnosed with COPD, although several received the diagnosis during the study. Asymptomatic daily smokers with normal lung function had mean CAT scores of 8.6, while symptomatic smokers with normal lung function had mean CAT scores of 13.0, as did the participants who had GOLD II disease. Those with severe COPD or exacerbation scored an average of 20.9. Take-home message: Even patients with a smoking history who have normal lung function, as well as those with mild-to-moderate COPD, may have significantly impaired quality of life. Consider beginning treatment early and optimizing management.2 

CAT and exacerbations.  Several studies found links between CAT scores and exacerbations. In one, high CAT scores were associated with exacerbation frequency even in patients with mild airflow limitation. These patients also were less active indoors and experienced more gastrointestinal reflux disease.3  Meanwhile, among 161 patients who completed the CAT during an exacerbation and at least 5 weeks after, the CAT score at the time of the exacerbation correlated significantly with systemic inflammatory markers, providing a reliable indication of exacerbation intensity that could  guide treatment. The score was also a good marker to assess improvement in the weeks following exacerbation.4

Finally, a retrospective study of 39 patients with moderate-to-severe COPD found that CAT provided a clear marker for worsening disease and functional capacity. The authors recommended using it to determine “more effective interventions in the natural history of the disease.” 5Screening for COPD. There is considerable debate as to the appropriateness of COPD screening, particularly in primary care offices where access to spirometry may be limited.6  After all, not every smoker develops COPD. A study that will be presented at ATS, however, found that smoking history, age > 55 years, and presence of exertional breathlessness reliably predicted patients at risk for COPD for whom spirometry is appropriate.7Dyspnea in COPD. Dyspnea is the classic symptom of COPD, one that clinicians aim to improve with treatment. However, a study to be presented at ATS found that 44% of a cohort of 42,175 COPD patients had clinically significantly dyspnea regardless of their GOLD stage and current treatment. Take-home message: A significant percentage of patients are not being treated aggressively enough to manage their symptoms and improve their quality of life.8 

Watch out for fatigue. More than half of COPD patients experience chronic fatigue. Yet there is disagreement on how to assess and manage fatigue in these patients, leading to significant underdiagnosis and undertreatment.9   A study that will be presented at ATS involving 101 patients with stable COPD found that 66% experienced fatigue, mainly those with more reduced lung function, shorter 6-minute walking distances, and greater dyspnea. These patients were also more likely to experience depression and anxiety than those without fatigue.10  Take-home message: Don’t ignore fatigue in your COPD patients. It could be contributing to other comorbidities and affecting quality of life, and it can be improved with proper management. Evidence-based approaches to improving fatigue in patients with COPD include pulmonary rehabilitation and nutritional support.11

Sleep Apnea at the American Thoracic Society Annual Meeting

In recent years, there has been a greater recognition of the cardiovascular and other health-related effects of breathing-related sleep disorders, particularly obstructive sleep apnea (OSA). At the same time, the disorder is being recognized and diagnosed more often. Today, about one in five adults has a high risk of OSA. The diagnosed prevalence is 2% to 20% depending on how the condition is defined.12,13

Thus, it is not surprising that more than 100 abstracts to be presented at ATS will deal with sleep-disordered breathing. A major focus is the link between metabolic disorders and OSA. One study, for instance, found that more than 25% of 255 OSA patients studied had impaired glucose tolerance, a major risk factor for diabetes and other metabolic disorders.14  Others found that the severity of OSA predicted diabetes risk, impaired pancreatic beta cell function, and insulin resistance, and was also associated with a significantly higher incidence of arterial hypertension.15, 16, 14Take-home message: Patients who have been diagnosed with OSA, or who are at risk for OSA, most likely have other cardiometabolic symptoms that should be addressed.

Conversely, clinicians may want to evaluate patients with cardiometabolic and OSA risk factors for OSA. That is particularly important given evidence that treating OSA can improve metabolic markers. In one meta-analysis being presented at ATS, researchers evaluated 9 studies with a total of 220 subjects and found a favorable effect of continuous positive airway pressure (CPAP) on insulin resistance, although they noted that the studies were mostly observational.17

However, a double-blind randomized, crossover clinical trial published in The New England Journal of Medicine ahead of the meeting, which will also be presented orally at ATS, found that CPAP treatment for 3 months significantly reduced blood systolic and diastolic blood pressure, total cholesterol, non HDL cholesterol, LDL cholesterol, triglycerides, and glycated hemoglobin, compared to sham treatment. It reversed the metabolic syndrome in 11 of the 86 treated patients (13%) compared to only 1 who had the sham treatment.18

Just because your patients are diagnosed with OSA doesn’t mean you have to turn them over to a sleep specialist for treatment. A study that will be presented at ATS found that after 6 months of management in a primary care setting, patients with symptomatic, moderate-to-severe OSA managed in a primary care setting had comparable outcomes (change in Epworth Sleepiness Scale, Functional Outcomes of Sleep questionnaire, and CPAP compliance) to a similar group receiving usual care in a sleep center.19  The primary care intervention that involved home-based auto-titrating of CPAP.

Clinicians should also be aware of “overlap syndrome,” in which patients have comorbid OSA and COPD. An analysis of 4,116 individuals with COPD ranging from mild to very severe found that 15% also had physician-diagnosed OSA. These patients were more likely to be males who had a history of heavy smoking. They were also more likely to have cardiovascular disease (CVD), diabetes, and hypertension, with a much higher risk of heart failure. The more severe their COPD, the more likely they were to have OSA.20  Take-home message: To reduce the risk of comorbid heart failure, identify OSA in COPD patients and COPD in OSA patients and treating both conditions simultaneously.

Asthma at the 2012 American Thoracic Society Meeting

Although the ATS is not the primary asthma-related US meeting, more than 100 studies on asthma will be presented there next week. One that should interest family practitioners and pediatricians is a longitudinal study that followed a cohort of nearly 500 newborns up to age 23. The researchers found a correlation between the timing of solid food introduction and the risk of wheezing at age 23. Infants who received solid food by 8 or 10 weeks of age, regardless of the type of food, were 84% and 122% more likely to be wheezing by age 23.

However, researchers found no increased risk of wheezing in infants who were introduced to solid food at 16 weeks. The study echoes other research showing that introducing solid food before the generally recommended age of 4 to 6 months can increase the risk of eczema. It also provides additional support to another birth cohort study that found that later introduction of solid food had little effect on the risk of developing atopic disease.21,22 

Other asthma-related presentations of interest to primary care clinicians:

•    Obesity and exercise-induced bronchospasm. Obese children are more likely to have exercise-induced bronchospasm if they have asthma, and worsening lung function is correlated with increasing body mass index (BMI). Researchers found a substantial decrease in FEV1 in obese children without asthma (25%) compared to 18% in those with asthma. Based on their findings, the authors recommended that clinicians screen obese children for pre- and post exercise pulmonary function, whether or not they have asthma.23

•    Inhaler technique. One of the major contributors to poor clinical outcomes in asthma patients is poor inhaler technique. Yet physicians often prescribe inhalers without providing adequate instruction on their use. A study that will be presented at ATS evaluated the effects of training instruction based on the American College of Chest Physician guidelines among 69 patients randomized to either verbal training or physical demonstration with a placebo device.

All participants made at least one initial mistake in using the device, most often not breathing out through their mouth before using the inhaler and not breathing in while releasing the medication dose. Doing is learning: Although technique improved significantly after instruction in both groups, the verbal group needed a median of 3 interventions for full improvement, while the demonstration group needed only 2.24  Take-home message: It’s crucial to assure that your patients know how to use their inhalers properly. The best and quickest way to achieve this may be to demonstrate how to use the inhaler, rather than just talking about it.

•    Inhaler knowledge. Another problem with devices is that there are just so many. Not just patients but also healthcare providers struggle with this variety. At the ATS meeting, a member of a research team will describe how they assessed 46 doctors, nurses, pharmacists, and respiratory therapists in their knowledge of and ability to use 4 inhaler devices (Spiriva Handihaler®, Advair Diskus®, ProAir HFA®, and Pulmicort Flexhaler®). They found knowledge scores ranging from 77% for PharmDs to 58% for physicians, and technical skill scores ranging from 84% for respiratory therapists to 60% for registered nurses.25  Take-home message: If you don’t understand how to use an inhaler, how can you explain it to your patients?
 

References:

1. Jones PW, Harding G, Berry P, et al. Development and first validation of the COPD Assessment Test. Eur Respir J. 2009;34(3):648-54.

2. Toljamo T, et al. Value Of COPD Assessment Test (CAT) In Symptomatic Smokers Without COPD. T. Toljamo, Am J Respir Crit Care Med 185;2012:A1505

3. Miyazaki M, et al. Analysis Of Comorbid Factors Raising CAT Scores In COPD Patients With Mild Airflow Limitation. Am J Respir Crit Care Med;185;2012:A1507

4. Mackay AJ, et al. Utility Of The COPD Assessment Test (CAT) To Evaluate Severity Of COPD Exacerbations. Am J Respir Crit Care Med 185;2012:A1513

5. Gomes T, et al. Measuring The Real Impact To Improve Management Of Disease. Am J Respir Crit Care Med 185;2012:A1508

6. Lin K, Watkins B, Johnson T, Rodriguez JA, Barton MB. Screening for Chronic Obstructive Pulmonary Disease Using Spirometry: Summary of the Evidence for the U.S. Preventive Services Task Force [Internet]. Rockville (MD): Agency for Healthcare Research and Quality (US); 2008.

7. N. Raghavan, et al. Utility Of The COPD Assessment Test (CAT) In Predicting A Diagnosis Of COPD. Am J Respir Crit Care Med 185;2012:A1506

8. Mullerova H, et al. Disease Burden Of Dyspnea In A Primary Care COPD Population. Am J Respir Crit Care Med 185;2012:A1518

9. Wong CJ, et al. Fatigue in patients with COPD participating in a pulmonary rehabilitation program. Int J Chronic Obstruct Dis. 2010;5:319-326.

10. Kentson MU, et al. Situational, Physiological And Psychological Factors Associated With COPD-Related Fatigue And Functional Limitations Due To Fatigue. Am J Respir Crit Care Med 185;2012:A1519

11. Payne C, Wiffen PJ, Martin S. Interventions for fatigue and weight loss in adults with advanced progressive illness. Cochrane Database Syst Rev. 2012 Jan 18;1:CD008427.

12. Young T, Palta M, Dempsey J, et al. Burden of sleep apnea: rationale, design, and major findings of the Wisconsin Sleep Cohort study. WMJ. 2009;108(5):246

.13. Epstein LJ, Kristo D, Strollo PJ, et al. Clinical guideline for the evaluation, management and long-term care of obstructive sleep apnea in adults. J Clin Sleep Med. 2009;5(3):263.

14. Sliwinksi P, et al. Relationship Between Arterial Hypertension And Impaired Glucose Tolerance (IGT) In Obstructive Sleep Apnoea (OSA) Patients. Am J Respir Crit Care Med. 185;2012:A2161

15. Gu C, et al. Impaired Glucose Tolerance And Pancreatic Beta Cell Function In Patients With Obstructive Sleep Apnea. Am J Respir Crit Care Med. 185;2012:A2165.

16. Zhao Q, et al. Correlation Analysis Of Obstructive Sleep Apnea And Insulin Resistance. Am J Respir Crit Care Med. 185;2012:A2163.

17. Iftikhar I. Meta-Analysis: Continuous Positive Airway Pressure Therapy Improves Insulin Resistance In Patients With Obstructive Sleep Apnea. Am J Respir Crit Care Med. 185;2012:A2162

18. Sharma SK, Agrawal S, Damodaran D, et al. CPAP for the metabolic syndrome in patients with obstructive sleep apnea. N Engl J Med. 2011 Dec 15;365(24):2277-86

19. Chai-Coetzer CL, et al. Randomised Controlled Trial To Evaluate A Simplified Model Of Care For Obstructive Sleep Apnea In Primary Care. Am J Respir Crit Care Med. 185;2012:A3853

20. Black-Shinn JL, et al. Overlap Syndrome Is Associated With Cardiovascular Disease. Am J Respir Crit Care Med. 185;2012:A2169

21. Tarini BA, et al. Systematic Review of the Relationship Between Early Introduction of Solid Foods to Infants and the Development of Allergic Disease. Arch Pediatr Adolesc Med. 2006;160:502-507

22. Zutavern A, et al. Timing of solid food introduction in relation to eczema, asthma, allergic rhinitis, and food and inhalant sensitization at the age of 6 years: results from the prospective birth cohort study LISA. Pediatrics. 2008 Jan;121(1):e44-52.

23. Concepcion E, et al. Exercise Induced Bronchospasm In Asthmatic And Non-Asthmatic Obese Children. Am J Respir Crit Care Med. 185;2012:A1767.

24. Jolly GP, et al. Evaluation Of Inhaler Usage Technique And Response To Educational Training In A Tertiary Health Care Centre. Am J Respir Crit Care Med. 185;2012:A3328

25. Lo T, et al. Modern Inhalers: to What Degree Are We Capable of Remembering How to Use Them? Am J Respir Crit Care Med. 185;2012:A3331