There is a lack of information about the frequency of obstructive sleep apnea (OSA) in primary Sjogren's syndrome (pSS). Using all-night polysomnography (PSG), this study aimed to investigate the frequency of OSA in pSS and the factors affecting the frequency of OSA in this condition.  METHODS: Consecutive patients with pSS who presented to the Collagen Tissue Diseases follow-up polyclinic of the Department of Chest Diseases between 1 April 2019 and 31 December, 2020, were included in the study. Demographic characteristics, chronic diseases, smoking history in pack-years, anthropometric data, Epworth Sleepiness Scale score, pulmonary function test parameters, current thorax computed tomography findings, and PSG data were recorded. The control group was created by the retrospective screening of patients admitted to the sleep polyclinic and who underwent PSG but did not have pSS.

OSA was detected in 37 (84%) of 44 patients with pSS who underwent PSG. Of 37 patients with OSA, 25 (68%) had moderate or severe OSA. Snoring and witnessed apneas, REM%, snoring index, and maximum apnea and maximum hypopnea duration were statistically significantly lower in the pSS group compared with the control group (p < 0.001, p = 0.003, p = 0.025, p = 0.001, p = 0.028, and p = 0.035, respectively).

The frequency of OSA in patients with pSS was 84%, with a decrease in REM%. Although a correlation between symptoms suggesting OSA and the presence of radiological lung involvement, spirometry, and DLCO values with OSA could not be demonstrated, physicians are recommended to be attentive for the presence of OSA in all patients with pSS and to investigate OSA using PSG.