Association between sarcoidosis and diabetes mellitus: a systematic review and meta-analysis

Background: Sarcoidosis is multisystem inflammatory granulomatosis that can potentially affect any organ of the human body. We aimed to estimate the prevalence of diabetes mellitus (DM) in sarcoidosis patients and determine the association between sarcoidosis and DM.Method: All relevant articles reporting the prevalence of DM in sarcoidosis published until September 19^th, 2020, were retrieved from ten electronic databases. We used the random effect model to perform the meta-analysis.Results: After screening 2,122 records, we included 19 studies (n = 18,686,162). The prevalence of DM in sarcoidosis patients was 12.7% (95% CI 10-16.1). The prevalence was highest in North America with 21.3% (13.5-31.8), followed by Europe 10.4 (7.9-13.7) and Asia 10% (1.8-39.7). Sarcoidosis patients had higher rates of DM compared to controls (OR 1.75; 95% CI 1.49-2.05). Sensitivity analysis, after removing the largest weighted study, did not reveal any effect on the significance of the results (OR 1.73; 95% CI 1.33-2.25).Conclusion: The prevalence of DM in sarcoidosis is considerably high, with increased odds of DM in sarcoidosis compared to healthy controls. Further research with a wide range of confounders is required to confirm the association of sarcoidosis with DM.