Arterial stiffness and endothelial function in obstructive sleep apnoea/hypopnoea syndrome.

BACKGROUND

Obstructive sleep apnoea-hypopnoea syndrome (OSAHS) is associated with increased cardiovascular morbidity and mortality. Our study examined arterial stiffness and endothelial function in subjects with OSAHS with no known cardiovascular disease compared to well-matched controls.

METHODS

Twenty subjects with OSAHS (defined as apnoea-hypopnoea index [AHI] > or =15 and Epworth Sleepiness Scale score > or =11) without cardiovascular disease and 20 well-matched controls underwent a comprehensive evaluation of arterial stiffness and endothelial function. Arterial stiffness was measured by applanation tonometry and cardiovascular magnetic resonance imaging (MRI) and endothelial function assessed by measuring vascular reactivity after administration of glyceryl trinitrate and salbutamol.

RESULTS

Subjects with OSAHS had increased arterial stiffness (augmentation index 19.3 [10.9] vs. 12.6 (10.2)%; p=0.017) and impaired endothelial function (change in augmentation index following salbutamol -4.3 (3.2) vs. -8.0 (4.9)%; p=0.02) compared to controls. Aortic distensibility, a measure of arterial stiffness, was negatively correlated with the AHI.

CONCLUSIONS

Our findings suggest that even in the absence of known cardiovascular disease, subjects with OSAHS have increased arterial stiffness and impaired endothelial function and are at increased risk for cardiovascular disease.