The Relationship of Obesity and OSA to the Development of Sarcoidosis: A Large Retrospective Case-Control US Veterans Administration Analysis.

Background: Previous studies have demonstrated an association between BMI and the development of sarcoidosis. We investigated this association and the association between OSA and the development of sarcoidosis in a US Veterans Health Administration database.

Research Questions: Is the presence of OSA or the BMI associated with the development of sarcoidosis over the subsequent 12 months?

Study Design And Methods: We identified patients with sarcoidosis and OSA through International Classification of Diseases, Ninth and Tenth Revision, codes. We selected a random sample of control participants with no record of sarcoidosis. All patients with sarcoidosis had at least one BMI value recorded in the 12 months before the sarcoidosis diagnosis was made. For the patients without sarcoidosis, the BMI values were obtained over intervals 12 months before a random date. We compared the BMI and the percentage of patients with OSA in the sarcoidosis group and in patients without sarcoidosis.

Results: We analyzed 10,512 patients with sarcoidosis and 2,709,884 patients without sarcoidosis. We found no association between BMI and the rate of sarcoidosis developing. Post hoc statistical power calculations verified that these null results were meaningful and not the result of insufficient statistical power. We also found that a diagnosis of OSA was protective of sarcoidosis developing. Using a conditional logistic regression model with strata for age, sex, and BMI in the same 12-month period, a 49.0% lower odds of sarcoidosis was found in patients with OSA compared with patients without a diagnosis of OSA. Although the primary outcomes were assessed at 12 months before the diagnosis of sarcoidosis, these results basically held when examined at 3 and 6 months before the diagnosis was made.

Interpretation: These findings suggest that increased BMI is not associated positively with a greater odds of sarcoidosis developing. Furthermore, these results suggest that the presence of OSA lowers the odds of sarcoidosis developing.