Analysis of Aortic Remodeling and Stiffness in Patients with Obstructive Sleep Apnea Syndrome: Preliminary Results

Obstructive sleep apnea (OSA) is a well-known risk factor for cardiovascular diseases. Several studies have shown that OSA is associated with vessel remodeling, but few studies have examined aorta.

to analyse aortic remodelling in OSA.

Thirty consecutive OSA patients (22 males and 8 females, aged 58.5 ± 13.2 years) were studied. All patients underwent a morning blood gas analysis, a full cardiorespiratory evaluation, including nocturnal polygraphy and echocardiography, that assessed aortic root diameter (ARD) and aortic stiffness index (ASI). Patients were grouped as follows: Group 1, non-severe OSA (Apnea-Hypopnea Index; AHI <30, 14 patients); Group 2, severe OSA (AHI ≥30, 16 patients).

No difference was found between the groups in ARD as absolute value (Group 1, 33.64 ± 0.91 mm; Group 2, 33.64 ± 1.02, p = ns) and as normalized value for the body surface area - ARDi (Group 1, 16.72 ± 0.63 mm/m²; Group 2, 16.09 ± 0.44, p = ns). Moreover, no difference was found in the ASI (Group 1, 14.04 ± 2.26; Group 2, 13.41 ± 2.22, p = ns). Considering all OSA patients, AHI showed an inverse correlation with ARDi (p = 0.018) and ASI (p = 0.0449). Moreover, the ASI showed a direct correlation with ARDi (p = 0.01) and morning PaO2 (p = 0.0349) as well as an inverse correlation with the oxygen desaturation index (ODI, p = 0.031) and total time with apnea and hypopnea (p = 0.039).

No difference was found between severe and non-severe OSA in ARD. Surprisingly, the data show that the severity of OSA correlates inversely with the ASI and ARDi. The relation between PaO2 and stiffness might be explained by a feedback mechanism that tries to overcome the reduction of aortic elasticity due to night desaturation. These findings need to be investigated in further studies with a larger study population.