Sleep Apnea a Potential Protective Factor Against Sarcoidosis: Study
The sleep disorder cuts the risk of developing sarcoidosis nearly in half, US veterans study suggests
The chance of developing sarcoidosis is nearly halved in those with obstructive sleep apnea (OSA), a sleeping disorder wherein breathing slows or stops repeatedly and for short times during sleep, according to a large study involving U.S. veterans.
The findings point to OSA as a protective factor for sarcoidosis. Body mass index (BMI), a measure of body fat based on height and weight, was not significantly associated with the inflammatory condition, however.
“These findings contradict other smaller analyses and reopen the question of the association of BMI and OSA with the development of sarcoidosis,” the researchers wrote.
The study, “The relationship of obesity and obstructive sleep apnea to the development of sarcoidosis: A large retrospective case-control US Veterans Administration analysis,” was published in Chest.
Some studies have shown that obese people may be at higher risk of developing sarcoidosis, compared with normal or underweight individuals. The reasons for this are not fully understood, but obesity is known to promote inflammation in multiple tissues, which could contribute to granulomas, or clumps of inflammatory cells that characterize the condition, forming.
Obesity is also a major risk factor for OSA, although the sleeping disorder by itself is also marked by an inflammatory state that could contribute to sarcoidosis.
It remains unclear whether higher BMI scores and an OSA diagnosis are associated with developing sarcoidosis.
Researchers at the Stratton Veterans Affairs Medical Center, New York drew on data from the national Veterans Health Administration database to study this link.
The study included 10,512 patients who received a diagnosis of sarcoidosis from October 1999 to April 2021 and had their BMI measured at least once in the year prior to the diagnosis. A total of 2,709,884 patient veterans with no record of sarcoidosis were included as controls.
People with sarcoidosis were a mean 3.7 years younger than control patients (55.5 vs. 59.2 years). They also were made up of a larger proportion of women (14.9% vs. 7.4%) and Black people (46.7% vs. 18.1%).
Results showed mean BMI scores in the 12 months leading up to a diagnosis were similar between sarcoidosis patients and controls (30.9 vs. 31.0). Consistently, the chance of developing the condition was not significantly different between groups, even after taking into account factors such age, sex, race, and an OSA diagnosis.
“Contrary to previous smaller studies, we did not find an association between obesity and the development of sarcoidosis,” the researchers wrote, adding that “these null results were meaningful and not due to insufficient statistical power.”
Analyses of BMI three and six months before a sarcoidosis diagnosis found a significantly smaller chance of having sarcoidosis with higher BMIs, but “the effect was very small and not meaningful practically,” the researchers wrote.
In contrast with BMI, significantly fewer patients with OSA developed sarcoidosis in the 12 months after being diagnosed with the sleeping condition (10% vs. 16.8%). After accounting for potential confounding factors, people with OSA were 49% less likely to develop sarcoidosis than those without OSA.
“We found that a diagnosis of OSA was protective of sarcoidosis developing across all statistical models, regardless of whether OSA had been established 3, 6, or 12 months before the sarcoidosis diagnosis was made,” the research team wrote.
The researchers noted that limitations to the study included the fact that diagnostic data was obtained from medical records.
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