Evolution With CPAP Treatment of a Cohort of Type 2 Diabetic Patients With Apnea-hypopnea Syndrome (DM2-CPAP)

Primary Outcome Measures:

• Change in Hemoglobine A1C from baseline [ Time Frame: 14, 28, 42 and 56 weeks after initial intervention. ]
  

Secondary Outcome Measures:

• Blood levels of fasting glucose from baseline [ Time Frame: 14 weeks after initial intervention ]
  
• Self measured capillary glucose profile [ Time Frame: 14 weeks after initial intervention ]
  
• Evening saliva collection for cortisol assay [ Time Frame: 14 weeks after initial intervention ]
  
• Noninvasive 24-hour ambulatory blood pressure monitoring [ Time Frame: 14 weeks after initial intervention. ]
  
• Analysis of urine to assess albumin to creatinine ratio [ Time Frame: 0, 14, 28, and 56 weeks after initial intervention. ]
  
• Blood levels of fasting insulin [ Time Frame: 14 weeks after initial intervention ]
  
• Blood levels of total cholesterol [ Time Frame: 14 weeks after initial intervention ]
  
• Blood levels of cholesterol HDL [ Time Frame: 14 weeks after initial intervention ]
  
• Blood levels of tryglicerids [ Time Frame: 14 weeks after initial intervention ]
  
• International Physical Activity Questionnaire [ Time Frame: 14 weeks after initial intervention ]
  
• Epworth Sleepiness Scale [ Time Frame: 14 weeks after initial intervention ]
  
• SF-36 v2 Health Survey [ Time Frame: 14 weeks after initial intervention ]
  
• subjective quantity and quality of sleep reported in a sleep log [ Time Frame: 14 weeks after initial intervention ]
  
• Change in ratio albumine to creatinine from baseline [ Time Frame: 14, 28, 42 and 56 weeks after initial intervention ]
  

Subjects with poorly controlled type 2 diabetes are a high cardiovascular risk group in which a high prevalence of moderate to severe sleep apnea is expected. Studies based on interstitial glycemic measurement demonstrate a reduction in glucose levels when treating sleep apnea with CPAP. Nevertheless, the effectiveness of CPAP in improving glycemic control has been questioned as most studies have failed to demonstrate a reduction in hemoglobin A1c (HbA1C) level over time. Most of these studies have limitations such as a short follow-up or a suboptimal fulfillment of CPAP treatment. We hypothesize that treating moderate to severe sleep apnea with CPAP will improve glycemic control (measured by HbA1C) at 14 weeks in good compliers and that this improvement will be sustained at one year. We aim to test this hypothesis in consecutive type 2 diabetes patients on stable treatment with HbA1c ≥7% in routine outpatient visits in our Diabetes, Nutrition and Endocrinology Unit. After providing informed consent, patients will be screened for sleep apnea by nocturnal oximetry followed by a diagnostic respiratory polygraphy. Those patients with obstructive sleep apnea with an apnea-hypopnea index ≥20 will be invited to enter the study. After a 3-month observation period without any intervention to rule out a potential influence of entering the study on HbA1C levels, patients will be treated with CPAP. HbA1C levels will be measured at baseline, after 14 weeks, and thereafter every 14 weeks until completing one year of treatment. Other endocrine, metabolic and cardiovascular risk variables will be determined at baseline and at 14 weeks of the intervention.