Introduction: Obstructive sleep apnea (OSA) is a risk factor for type 2 diabetes that adversely impacts glycemic control. However, there is little evidence about the effect of continuous positive airway pressure (CPAP) on glycemic control in patients with diabetes.
Aim: Assess the effect of CPAP on glycated hemoglobin (HbA1c) levels in patients with type 2 diabetes and OSA.
Methods: it was a prospective study including type 2 diabetic patients with OSA and a CPAP therapy indication. All participants had HbA1c measurement at baseline (T0) and 2 months after the onset of CPAP (T1) with a compliance ≥ 4 hours / night. Patients who changed anti-diabetic treatment during follow-up were excluded. The HbA1c level goal was ≤ 7%.
Results: Thirty patients were included (4 men and 26 women) with a mean age of 61.3 ± 8.8 years. The mean diabetes duration was 5.8 ± 3.7 years. Twenty-four patients had poorly controlled diabetes. Associated comorbidities were dominated by hypertension (n=22) and obesity (n=22). The mean apnea hypopnea index was 38.0 ± 12.7/ hour. Two months after the CPAP use, a significant decrease of 1.1 ± 0.8 % in the mean HbA1c level was observed (HbA1c: T0= 8.9 ± 1.5 % vs T1=7.8 ± 1.1 %; p<0.001). This rate was significantly correlated with the body weight (r = 0.51, p = 0.003), the body mass index (r = 0.42, p = 0.02) and the HbA1c level at baseline (r = 0, 76, p <0.001). The only factor associated with glycemic control improvement was an initial HbA1c level > 9% (Odds Ratio = 8.3, p = 0.04).
Conclusion: CPAP therapy improved diabetes control in type 2 diabetic patients with OSA, in particular in those with an initial HbA1c> 9%.