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To Clinicians: The International Diabetes federation consensus statement.
June 12, 2008 — The International Diabetes Federation (IDF) has issued a consensus statement on type 2 diabetes and obstructive sleep apnea (OSA) to assist clinicians in diagnosis, treatment, and prevention. The statement was published in the July issue of Diabetes Research and Clinical Practice and online on the IDF Web site.
"Recent research demonstrates the likelihood of a relationship between sleep-disordered breathing (SDB) and type 2 diabetes," write co-chair Paul Zimmet, AO, MD, PhD, from Melbourne, Australia, and colleagues from the IDF Task Force on Epidemiology and Prevention. "Whilst the exact nature of the relationship between the two conditions remains uncertain, the association between them has important implications for public health and for individuals. Additionally, both type 2 diabetes and SDB are strongly associated with cardiovascular disease (CVD)."
The IDF Task Force on Epidemiology and Prevention convened a working group on sleep-disordered breathing and type 2 diabetes in 2007. Their goal was to review and evaluate current evidence information on sleep-disordered breathing and type 2 diabetes to make recommendations both for management and for further research.
Both type 2 diabetes (as well as abnormal glucose metabolism) and OSA have a high prevalence and often coexist. Although OSA, hypertension, and cardiovascular disease are also interrelated, this association may go beyond shared risk factors such as obesity, based on accumulating evidence. The IDF has mandated heightened awareness, improved clinical practice, and further scientific investigation into the links between type 2 diabetes and OSA because both conditions increase the risk for cardiovascular morbidity and mortality as well as for other adverse sequelae.
The benefits of treating OSA include better quality of life and blood pressure control. Although treating OSA may also improve glycemic control, obesity, and other cardiovascular risk factors, evidence regarding these potential benefits has been inconsistent to date.
For the treatment of OSA, the IDF recommends weight reduction in overweight and obese patients, avoidance of alcohol and sedative drugs, and use of continuous positive airway pressure (CPAP) treatment or dental appliances.
CPAP treatment uses a mask that is worn over the nose or mouth during sleep and that is linked to a machine delivering a continuous stream of compressed air to create positive pressure that helps keep the airways open and facilitates breathing. Dental appliances, which can be specifically designed by dentists with special expertise in the treatment of sleep apnea, can also keep the airway open during sleep.
In some cases, surgery may be indicated for OSA, if patients have enlarged tonsils and adenoids, nasal polyps, or facial deformities including a small jaw or a deviated nasal septum.
Individuals diagnosed with either type 2 diabetes or OSA should be screened for the other condition, according to the IDF. Those with OSA should be routinely screened for metabolic syndrome and type 2 diabetes because these screening tests are inexpensive and are easily performed, including waist measurement, blood pressure measurement, and levels of fasting lipids and glucose.
When indicated on the basis of these tests, a glucose tolerance test should also be performed. All persons with OSA should undergo monitoring of metabolic parameters, and those diagnosed with type 2 diabetes or its forerunners should be treated to reduce the risk for microvascular and macrovascular diabetic complications.
Particularly in the presence of classic symptoms such as witnessed apneas, heavy snoring, or daytime sleepiness, individuals diagnosed with diabetes should be screened for OSA. Appropriate testing with sleep study in a laboratory is useful, but simpler home monitoring devices can facilitate the diagnosis of OSA where facilities are limited.
"To date, there is not enough evidence to support screening of OSA in all people with diabetes since there is no conclusive evidence that treatment of OSA will improve metabolic parameters," the study authors write. "Until more research information is available, IDF recommends a practical approach which is to investigate those people with classical symptoms such as witnessed apnoeas, heavy snoring or daytime sleepiness, despite the fact that some people with OSA will not be identified this way. People with diabetes with refractory hypertension should also be considered for screening since treating OSA may improve blood pressure."
Screening questionnaires for OSA are not suitably specific for individuals with diabetes, who often report fatigue and daytime sleepiness even in the absence of OSA. However, people with symptomatic daytime sleepiness are most likely to benefit from treatment of OSA and are most likely to be compliant with long-term treatment. Therefore, identifying these symptoms in patients with diabetes may be useful, even if not specific for OSA.
In-laboratory polysomnography to diagnose OSA is expensive and may not be available in all clinical settings. A 2-stage approach may be useful in which a structured questionnaire, such as the Berlin questionnaire, is administered first to determine the likelihood of sleep apnea. Those classified as high risk based on the questionnaire may undergo additional testing with an overnight evaluation at home with pulse oximetry or portable monitoring.
Polysomnography may be indicated in individuals with a high pretest probability of OSA but with negative results on portable monitoring. Those with evidence of some form of sleep apnea should ideally be referred to a sleep specialist. Alternatively, an empiric trial of CPAP therapy with an autotitrating device may be prescribed under the supervision of a primary care clinician and a trained respiratory therapist.
"IDF recommends that all healthcare professionals involved with diabetes or OSA should be educated about the links between the two conditions and trained in their care," the statement authors conclude. "Further research is needed to better understand the links between the two conditions and improve treatment and care. Finally, health policy makers and the general public must also be made more aware of OSA and the significant financial and disability burden that it places on both individuals and societies."
The ResMed Foundation supported the workshop on sleep apnea and type 2 diabetes.
Diabetes Res Clinical Pract. 2008;81:2-12.
Clinical Context
The exact nature of the association between sleep-disordered breathing and type 2 diabetes, though still unclear, has important implications for public health as well as for individual patients, in part because both conditions are linked to cardiovascular disease. Although type 2 diabetes is highly recognized among clinicians and the public, awareness of sleep-disordered breathing is not as great, despite the associated healthcare costs and reduction in quality of life.
In 2007, the IDF Task Force on Epidemiology and Prevention convened a working group on sleep-disordered breathing and type 2 diabetes to review current evidence concerning these conditions and to make recommendations for both treatment and research. The Task Force recommended a global, multidisciplinary approach and generated a statement intended to facilitate prevention, diagnosis, and treatment of OSA and diabetes by healthcare professionals.
Study Highlights
- Individuals diagnosed with either type 2 diabetes or OSA should be screened for the other condition.
- Those with OSA should be routinely screened for metabolic syndrome and type 2 diabetes with inexpensive, easily performed screening tests: waist and blood pressure measurement and levels of fasting lipids and glucose.
- A glucose tolerance test should also be performed when these test results are positive.
- Persons diagnosed with type 2 diabetes or its forerunners should be treated to reduce the risk for microvascular and macrovascular diabetic complications.
- Individuals diagnosed with diabetes should be screened for OSA, particularly when witnessed apneas, heavy snoring, or daytime sleepiness is present.
- People with diabetes with refractory hypertension should also be considered for screening because treating OSA may improve blood pressure.
- Because people with diabetes often report fatigue and daytime sleepiness even in the absence of OSA, screening questionnaires for OSA are not very specific in these patients.
- However, identifying these symptoms in patients with diabetes may be useful because people with symptomatic daytime sleepiness are most likely to benefit from treatment of OSA and are most likely to be compliant with long-term treatment.
- A structured questionnaire (eg, the Berlin questionnaire) may be given first to determine the likelihood of sleep apnea.
- Patients classified as high risk on the questionnaire may undergo additional testing with overnight evaluation at home with pulse oximetry or portable monitoring.
- Polysomnography may be indicated in individuals with a high pretest probability of OSA but with negative results on portable monitoring.
- Patients with evidence of some form of sleep apnea should ideally be referred to a sleep specialist.
- A primary care clinician may also prescribe an empiric trial of CPAP therapy with an autotitrating device, with the assistance of a trained respiratory therapist.
- Treating OSA improves quality of life and blood pressure control.
- Treating OSA may also improve glycemic control, obesity, and other cardiovascular risk factors, but evidence is unclear to date.
- Treatment of OSA includes weight reduction in overweight and obese patients, avoidance of alcohol and sedatives, and use of CPAP or dental appliances to keep the airways open and facilitate breathing.
- Surgery may be indicated for patients with OSA who have enlarged tonsils and adenoids, nasal polyps, a small jaw, or a deviated nasal septum.
Pearls for Practice
- Individuals diagnosed with either type 2 diabetes or OSA should be screened for the other condition. Those with OSA should be routinely screened for metabolic syndrome and type 2 diabetes with inexpensive, easily performed screening tests, followed by a glucose tolerance test when these test results are positive.
- Individuals diagnosed with diabetes should be screened for OSA, particularly when witnessed apneas, heavy snoring, or daytime sleepiness is present. A structured questionnaire may be given first to determine the likelihood of sleep apnea. Patients classified as high risk may undergo additional testing with overnight evaluation at home with pulse oximetry or portable monitoring.
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