Prevalence and predictive factors of sleep apnoea syndrome in type 2 diabetic patients

Abstract Aim This study aimed to assess the prevalence and characteristics of sleep apnoea syndrome (SAS) in patients hospitalized for poorly controlled type 2 diabetes. Methods An overnight ventilatory polygraphic study was systematically performed in 303 consecutive patients. Results Overall, 34% of these patients had mild SAS, as defined by a respiratory disturbance index (RDI) of 5–15; 19% had moderate SAS (RDI: 16–29) and 10% had severe SAS (RDI≥30). The SAS was obstructive in 99% of the apnoeic patients. The percentage of patients with excessive daytime sleepiness (Epworth sleepiness scale>10), fatigue or nocturia did not significantly differ among patients with severe, moderate or mild SAS versus non-apnoeic patients. The percentage of patients who snored was significantly higher in patients with severe or moderate SAS versus non-apnoeic patients. HbA 1c , duration of diabetes and the prevalences of microalbuminuria, retinopathy and peripheral neuropathy did not significantly differ among patients with severe, moderate or mild SAS versus non-apnoeic patients. However, patients with severe or moderate SAS had significantly higher values for body mass index, waist circumference and neck circumference than non-apnoeic patients. Conclusion In type 2 diabetic patients with poor diabetic control, obstructive SAS is highly prevalent and related to abdominal obesity, and should be systematically screened for, as it cannot be predicted by the clinical data.