Wake up to sleep

The International Diabetes Federation issued a consensus report on sleep-disordered breathing and type 2 diabetes.

At the June 2008 Annual Scientific Sessions of the American Diabetes Association, an important document was unveiled that deserves our attention: The International Diabetes Federation’s report entitled “Sleep-Disordered Breathing and Type 2 Diabetes.”

The call to action is for a “global, multidisciplinary approach to raise awareness, improve clinical practice and coordinate research efforts to better understand the links between sleep-disordered breathing and type 2 diabetes.” Although the vast scale of the type 2 diabetes epidemic has long been acknowledged by health care professionals the world over, the magnitude of the problem of obstructive sleep apnea has not been as well recognized, despite its clinical significance. Obstructive sleep apnea is associated with hypertension, metabolic syndrome, type 2 diabetes, cardiovascular disease and obesity. Despite the evidence, nearly 80% of people with sleep apnea remain undiagnosed and untreated.

Virginia Zamudio Lange

Obstructive sleep apnea is characterized by the presence of abnormal breathing during sleep as well as the presence of excessive daytime sleepiness. During sleep, the upper airway collapses repeatedly, resulting in periods of hypopnea (a decrease in airflow for 10 or more seconds with resultant oxygen desaturation) or apnea (defined as no airflow for 10 or more seconds). Sleep partners typically observe loud snoring, as well as periods in which the patient ceases to breathe, or makes choking sounds. Patients with obstructive sleep apnea may exhibit daytime fatigue and lack of energy, irritability, problems with memory, depressive symptoms, morning headaches, sexual dysfunction, and nocturia.

The IDF’s recommendations are for all health care professionals who treat those with type 2 diabetes and metabolic syndrome to adopt clinical practices to screen these patients for obstructive sleep apnea. Conversely, any patient who presents with obstructive sleep apnea should be considered for type 2 diabetes.

IDF screening recommendations

Patients with obstructive sleep apnea: Screen for markers of metabolic disturbance and CV risk: waist circumference, blood pressure, fasting lipid profile, and fasting blood glucose.

Patients with type 2 diabetes/metabolic syndrome: Assess for obstructive sleep apnea symptoms, such as snoring, observed apnea during sleep and daytime sleepiness. These cardinal features of obstructive sleep apnea can easily be assessed using validated questionnaires such as the Berlin Questionnaire or Epworth Sleepiness Scale.

Refer patients with positive obstructive sleep apnea symptoms to a qualified professional for an overnight sleep study. Alternately, a home sleep study can be performed utilizing oximetry and other leads which measure respiratory effort and nasal air flow. Ideally, the professional reading the polysomnography tracing should be board certified in sleep medicine.

If obstructive sleep apnea is diagnosed, initial management should be on weight loss for overweight and obese patients. If obstructive sleep apnea is moderate to severe, then continuous positive airway pressure treatment should be instituted. Currently, continuous positive airway pressure is the best treatment for moderate to severe obstructive sleep apnea.

CPAP benefits

The benefits of effective obstructive sleep apnea treatment are well-established. Clinical research has proven that continuous positive airway pressure therapy improves BP and insulin sensitivity. It can significantly lower BP in hypertensive patients during both sleep and wakefulness. In a study by Becker et al, patients with obstructive sleep apnea using effective continuous positive airway pressure therapy experienced a 10 mmHg drop in mean systolic BP, compared to no change in those using sub-therapeutic continuous positive airway pressure therapy. A three-month prospective study by Harsch et al, involving non-obese, non-diabetic subjects, demonstrated that insulin sensitivity improved within two days (P<.001) after introducing continuous positive airway pressure therapy. Obese subjects in this study demonstrated improvement in insulin sensitivity, but less than their non-obese counterparts. Babu and Herdegen showed that both HbA1c and postprandial glucose values improve significantly with the use of continuous positive airway pressure in patients with type 2 diabetes. The same study suggested that continuous positive airway pressure treatment may prevent or delay the progression to diabetes in sleep apnea patients.

Implementing a screening protocol in practice

To institute a screening protocol for obstructive sleep apnea in clinical practice, start by adding the following questions to your existing patient intake assessment: Do you snore? Do you wake up tired after a full night’s sleep? Are you being treated for high BP? If the patient responds positively to any of these questions, then investigate further by having the patient complete a validated screening tool such as the Berlin Questionnaire. If scoring high risk for obstructive sleep apnea on this tool, refer the patient to a qualified professional for a sleep study.

Awareness

The IDF recommends that given the scope of the problem, all health care professionals who treat patients with diabetes or obstructive sleep apnea be educated on the connection between type 2 diabetes and sleep apnea, and appropriate treatment for obstructive sleep apnea. Likewise health care policy decision makers should be made aware of the considerable financial burden that undiagnosed and untreated obstructive sleep apnea places on individuals and the population at large. Efforts should be made to inform the general public about the link between obstructive sleep apnea and type 2 diabetes, and the importance of instituting effective therapy.

Virginia Zamudio Lange, RN, MSN, CDE, is a diabetes educator at Alamo Diabetes Team in San Antonio, Texas, is Chief Medical Editor of Diabetes Vital and is a member of the Endocrine Today Editorial Board.

For more information:

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