Table 2.

Studies examining the effects of continuous positive airway pressure (CPAP) treatment of obstructive sleep apnea (OSA) on measures of glucose metabolism in patients with type 2 diabetes

Author/Year	Sample	Measures of Glucose Metabolism	Treatment duration	CPAP adherence (h/night)	Main findings
Brooks et al.[26] (1994)	10	Hyperinsulinemic euglycemic clamp	4 months	Not reported	No change in HbA1c Improvement in insulin sensitivity
Harsch et al. [46] (2004)	9	Hyperinsulinemic euglycemic clamp, HbA1c	3 months	∼ 5.8 hours	No change in HbA1c Improvement in insulin sensitivity
Babu et al.[44] (2005)	25	Continuous glucose monitoring, HbA1c	∼ 12 weeks	∼ 4.2 hours	Improvements in HbA1c and postprandial glucose levels
West et al.[42] (2007)	20 (CPAP) 22 (sham CPAP)	Hyperinsulinemic euglycemic clamp, HOMA, HbA1c	3 months	∼ 3.3 hours	No change on HbA1c or insulin sensitivity
Pallayova et al.[45] (2008)	14	Continuous glucose monitoring	1 night	Not reported	Improvement in nocturnal glucose levels
Dawson et al. [43] (2008)	20	Continuous glucose monitoring, HbA1c	∼ 5 weeks	∼ 5.8 hours	Improvement in glucose levels during sleep No change in HbA1c