Left ventricular diastolic dysfunction is linked to severity of obstructive sleep apnoea

Obstructive sleep apnoea (OSA) has been linked to increased cardiovascular risk. The present study examined the relationships between respiratory parameters and left ventricular abnormalities in OSA. 150 newly diagnosed OSA patients without any known cardiovascular disease were included in the study (mean +/- SD age 49 +/- 11 yrs, body mass index 27.1 +/- 3.3 kg.m(-2), respiratory disturbance index 41 +/- 18 h(-1)). Haemodynamic, biological, respiratory, cardiac and arterial parameters were assessed at inclusion. 34 (22.7%) patients had a grade 1 left ventricular diastolic dysfunction. Patients with an abnormal diastole were older (p<0.001) and 81% of them were hypertensive. The only respiratory parameter independently associated with the peak flow velocity in early diastole/peak flow velocity at atrial contraction ratio was mean nocturnal oxygen saturation. 17 (13%) patients had left ventricular hypertrophy. A multivariate analysis showed that clinic systolic blood pressure and mean nocturnal oxygen saturation were independently associated with left ventricular hypertrophy. In a logistic regression model, age >= 58 yrs (OR 3.29, 95% CI 1.78-5.64) and mean nocturnal oxygen saturation <92% (OR 2.76, 95% CI 1.45-4.91) were associated with left ventricular diastolic dysfunction. Our findings demonstrate that left ventricular diastolic dysfunction frequently occurs in patients with OSA and that it is related to the severity of oxygen desaturation.