Obstructive Sleep Apnea Common in Primary Sjögren’s Syndrome, Turkish Study Shows
Obstructive sleep apnea (OSA), which occurs when breathing slows or stops repeatedly for short times during sleep, is common among people with primary Sjögren’s syndrome, a study found.
Since OSA is associated with an increased risk for cardiovascular problems, fatigue, and other medical problems, physicians should monitor all people with primary Sjögren’s syndrome for the presence of OSA, its researchers wrote.
The study, “The frequency of obstructive sleep apnea in patients with primary Sjogren’s syndrome,” was published in Sleep and Breathing.
OSA occurs when the upper airways become blocked — fully or partly — during sleep, leading to snoring, pauses in breathing, and nocturnal desaturation (a temporary decrease in the amount of oxygen in the blood). It can result in excessive daytime sleepiness and fatigue, mood changes, and cardiovascular diseases.
There is evidence that OSA is common among people with autoimmune diseases, and one study found that people with Sjögren’s have more than double the risk of developing OSA than people without autoimmune diseases.
However, more studies are needed to determine how common it actually is among those with Sjögren’s syndrome and what factors contribute to the risk of OSA in these patients.
To address that, a team of researchers in Turkey examined retrospective data from 44 patients with primary Sjögren’s syndrome who underwent a polysomnography (PSG) between April 2019 and December 2020.
A PSG is a form of all-night study that examines a person’s sleep, such as duration, efficiency, and sleep phases, while monitoring the electrical activity in the brain, the amount of oxygen in the blood, heart rate, and breathing, as well as leg and eye movements.
The patients included 42 women and two men, with a mean age of 56. A group of 88 women who also underwent PSG but did not have Sjögren’s were included as controls.
In patients, symptoms suggestive of OSA were excessive daytime sleepiness (observed in 75% of patients), witnessed apnea (interrupted breathing during sleep; 61%), and snoring (30%). A diagnosis was confirmed in 37 (84%) of them, with the majority having moderate OSA (43%).
“This high rate shows that the presence of OSA is substantial in patients with pSS [primary Sjögren’s syndrome] and requires attention,” the researchers wrote.
Compared with patients without OSA, those with the sleep disorder were significantly older and more likely to be overweight or obese, consistent with the known associations between older age and excess weight with OSA. However, measures of lung function and lung imaging were not linked to OSA.
In controls, the percentage of OSA diagnoses was 77%, which was not significantly different from patients. Yet patients with OSA experienced fewer and shorter episodes of snoring and witnessed apnea than controls with OSA.
“These findings suggest that witnessed apnea and snoring may be insufficient in predicting the presence of OSA in pSS,” the researchers wrote. “For this reason, we recommend that patients with pSS without snoring and witnessed apnea should also be evaluated using PSG for the presence of OSA.”
The proportion of rapid eye movement (REM) sleep (a part of sleep when dreams are typically more vivid that is important for learning and memory consolidation), the time with reduced airflow, and maximum apnea were also significantly lower in patients.
As a limitation of the study, the researchers noted that the control group may not entirely reflect the healthy population and that such a group could be difficult to establish, particularly during the COVID-19 pandemic.