CPAP treatment, glycaemia and diabetes risk in obstructive sleep apnoea with comorbid cardiovascular disease

CPAP treatment, glycaemia and diabetes risk in obstructive sleep apnoea with comorbid cardiovascular disease





K. Loffler1, C.S. Anderson2, R.D. McEvoy1, L.F. Drager3



1Flinders University, Bedford Park, Adelaide, Australia; 2The George Institute for Global Health, Peking University Health Science Center, Beijing, China; 3Instituto do Coracao (Incor) and Hospital Universitario, Faculty of Medicine, University of Sao Paulo, Sao Paolo, Brazil



Introduction



Despite evidence of a relationship between obstructive sleep apnoea (OSA), metabolic dysregulation and diabetes mellitus (DM), it is uncertain whether OSA treatment can improve metabolic parameters. We sought to determine effects of long‐term continuous positive airway pressure (CPAP) treatment on glycaemic control and DM risk in patients with cardiovascular disease (CVD) and OSA.



Methods



Blood, medical history, demographic and anthropometric data were collected in a substudy of the international Sleep Apnea Cardiovascular Endpoints (SAVE) trial. 888 individuals with OSA and stable CVD were randomised to receive CPAP plus usual care, or usual care alone. Serum glucose and glycated haemoglobin A1c (HbA1c) were measured at baseline, and at six months, two‐ and four years, post‐randomisation, and new DM diagnoses recorded.



Results



Median follow‐up was 4.3 years. CPAP and usual‐care groups were well balanced. In those with pre‐existing diabetes, there was no statistically significant difference between the CPAP and usual care groups in serum glucose (mean difference −0.26 mmol/L, 95% CI –0.77 to 0.25; p = 0.321), HbA1c (mean difference 0.09%, 95% CI 0.36 to 0.18; p = 0.525), nor in anti‐DM medications during follow‐up. There were also no between group differences in non‐diabetic patients, nor new diagnoses of DM.



Discussion



Among patients with established CVD and OSA, CPAP therapy over several years did not affect glycaemic control or DM risk over standard of care treatment.