Impact of obstructive sleep apnoea on diastolic function.

We investigated whether obstructive sleep apnoea (OSA) independently affects diastolic function in a primary care cohort of patients with cardiovascular risk factors. 378 study participants with risk factors for diastolic dysfunction were prospectively included and a polygraphy was performed in all patients. Diastolic dysfunction was assessed by comprehensive echocardiography including tissue Doppler. Sleep apnoea was classified according to apnoea/hypopnoea index (AHI) as none (AHI <5 events·h(-1)), mild (AHI ≤5 to <15 events·h(-1)) or moderate-to-severe (AHI ≥15 events·h(-1)). Patients with central sleep apnoea (n=14) and patients with previously diagnosed sleep apnoea (n=12) were excluded. In the remaining 352 subjects, 21.6% had an AHI ≥15 events·h(-1). The prevalence of diastolic dysfunction increased with the severity of sleep apnoea from 44.8% (none) to 56.8% (mild) to 69.7% (moderate-to-severe sleep apnoea) (p=0.002). The degree of diastolic dysfunction also increased with sleep apnoea severity (p=0.004). In univariate regression analysis, age, desaturation index, AHI, cardiac frequency, angiotensin receptor 1 antagonist therapy, body mass index (BMI) and left ventricular mass were associated with diastolic dysfunction. In multivariate regression analysis, only age, BMI, AHI and cardiac frequency were independently associated with diastolic dysfunction. Moderate-to-severe OSA is independently associated with diastolic dysfunction in patients with classical risk factors for diastolic dysfunction.