Relationship between parenchymal involvement and obstructive sleep apnea in subjects with sarcoidosis

Increased obstructive sleep apnea (OSA) incidence has been reported in sarcoidosis. However, no research has been conducted to determine the relation between OSA and pulmonary parenchymal involvement in sarcoidosis.

We investigated OSA frequency and association between pulmonary parenchymal involvement and OSA in sarcoidosis. Additionally, relationship between lung functions and polysomnography data was assessed.

The study enrolled sarcoidosis subjects with or without pulmonary parenchymal involvement. Spirometry, diffusion capacity, 6-min walking test, arterial blood gases, chest X-ray, Epworth sleepiness scale (ESS) and polysomnography were performed. Subjects with body mass index (BMI) ≥30 or significant upper airway pathologies that might cause OSA were excluded.

A total of 29 sarcoidosis subjects (15 with, 14 without parenchymal involvement) with mean age 43.8 ± 9.4 years were analyzed. Twenty-seven of them were female. BMI was 26.8 ± 4.2 kg/m(2) . Mean forced expiratory volume 1 s (FEV1 ) was 97.89% ± 20.21%, and forced vital capacity (FVC) was 102.86 ± 18.14%. ESS score was 4 ± 1.6. OSA was identified in 51.7% (n = 15) of subjects. Apnea-hypopnea index (AHI) was 16.16 ± 19/h and oxygen desaturation index (ODI) was 22.3 ± 25.99 among subjects with OSA. Sleep apnea related with rapid eye movement was present in 40% of OSA subjects. AHI and ODI were higher among sarcoidosis subjects with parenchymal involvement (P = 0.019, P = 0.026). OSA frequency was higher in the group with parenchymal involvement, but the difference was not statistically significant (n = 10/15, %66 vs n = 5/14, %35). FEV1 and FVC were not related with AHI and ODI.

We found a high rate of OSA in sarcoidosis. There was a trend of high OSA frequency in sarcoidosis subjects with parenchymal involvement.