Among people with diabetes, the prevalence of sleep apnoea has been reported to be between 58-86%.1-4 Similarly, there is a high prevalence of impaired glucose tolerance and diabetes among people with sleep apnoea (in one study 50% of male sleep apnoea patients had abnormal glucose tolerance, and 30% of them had diabetes).5 Botros et al.6 reported a significantly higher probability of developing T2DM in patients with coinciding OSA than those without OSA. In light of the growing data supporting a significant link between T2DM and OSA, in 2008 the International Diabetes Federation recommended that health professionals ensure that patients presenting with one of these conditions is considered and monitored for the other.7
Obesity is a common and contributing factor to both sleep apnoea and diabetes. However, despite the significance of obesity in both these diseases, studies have shown that sleep apnoea is an additional contributing factor that is independently associated with glucose intolerance and insulin resistance, regardless of obesity.8,9 Insulin resistance is a precursor to diabetes.
CPAP may improve insulin sensitivity and glycemic control in patients with sleep apnoea, particularly for non-obese patients.10,11