Arterial Stiffness in Patients with Sarcoidosis and Obstructive Sleep Apnea

Abstract

Background: Obstructive sleep apnea (OSA) and sarcoidosis have both been implied to be risk factors for increased arterial stiffness. However, it is unclear whether an elevated apnea–hypopnea index (AHI) in sarcoidosis patients increases arterial stiffness and thus the cardiovascular risk. Methods: We performed non-invasive applanation tonometry in 57 adults with sarcoidosis. The participants underwent SphygmoCor to assess arterial stiffness using an aortic augmentation index with a heart rate of 75/min (AIx) and level-3 respiratory polygraphy. An AHI of ≥5/h, ≥15/h, and ≥30/h defined mild, moderate, and severe OSA, respectively. Multivariate regression analysis was used to investigate the association between AIx and AHI, adjusted for prespecified risk factors for AIx. Results: 23 (40%) sarcoidosis patients had at least mild OSA (AHI ≥ 5), while 7 (12%) patients showed AHI ≥ 15/h. AHI was significantly associated with AIx (coef. (95%CI) of 0.31 (0.09/0.52), p = 0.006) even after adjustment for known risk factors of arterial stiffness. While severe OSA was positively associated with increased AIx, mild and moderate OSA were not associated with increased AIx after adjusting for known risk factors. Conclusions: Increased AHI is independently associated with increased arterial stiffness in sarcoidosis patients. Further investigations are needed to underline the association between OSA severity and the magnitude of arterial stiffness.