Nocturnal oxygen desaturation correlates with glycemia levels in patients with coronary artery disease.

Aim: Sleep-disordered breathing (SDB) has a high occurrence in patients with coronary artery disease. The aim of the present study was to examine the relationships between the overnight oxygen desaturation index (ODI) and metabolic and anthropometric parameters in a sample of patients who underwent percutaneous transluminal coronary angioplasty (PTCA).
Methods: The overnight pulse-oximetry recording ODI (desaturation >4%, length >10 s/events per hour) was performed in 29 patients with coronary heart disease, after they underwent PTCA. All study participants performed dynamic spirometric test, echocardiography, anthropometric measurements, bio impedance analysis. Fasting blood sample was collected to measure metabolic parameters. Using ODI category, the patients were grouped as follows: group N, N.=9 (ODI= or <5 events/hour); group A, N.=14 (5<ODI= or <15 events/hour); group B, N.=6 (ODI>15 events/hour).
Results: Among the studied patients, 69% had a nocturnal ODI>5 and 48% had a nocturnal ODI between 5 and 15 events/hour. ODI values were correlated with body mass index (BMI) (P<0.05) but not with waist to hip ratio, or percent body fat. After adjustment for BMI values, there was a significant positive correlation of ODI values with fasting glucose serum levels (P<0.05).
Conclusion: These data suggest that early metabolic dysfunction may occur with SDB before overt clinical manifestation of underlying disease in patients with preobesity and ischemic heart disease. Patients with ischemic heart disease should be screened for SDB by ODI, also according to fasting glucose levels.