Type 2 diabetes risk in sarcoidosis patients untreated and treated with corticosteroids
BackgroundThe rate of type 2 diabetes mellitus (T2D) is increased in sarcoidosis patients but it is unknown if corticosteroid treatment plays a role. We investigated whether the T2D risk is higher in untreated and corticosteroid-treated sarcoidosis patients compared to the general population.MethodsIn this cohort study individuals with ≥2 ICD codes for sarcoidosis were identified from the Swedish National Patient Register (NPR; n=5754). Corticosteroid dispensations ±3 months from first sarcoidosis diagnosis were identified from the Prescribed Drug Register (PDR). General population comparators without sarcoidosis were matched to cases 10:1 on age, sex and region of residence (n=61 297). Incident T2D was identified using ICD codes (NPR) and antidiabetic drug dispensations (PDR). Follow-up was from second sarcoidosis diagnosis/matching date until T2D, emigration, death or study end (Dec 2013). Cox regression models adjusted for age, sex, education, country of birth, healthcare regions and family history of diabetes estimated hazard ratios (HR 95%CI). We used flexible parametric models to examine the T2D risk over time.Results40% of sarcoidosis patients were corticosteroid-treated at diagnosis. The T2D rate was 7.7/1000 person-years in untreated sarcoidosis, 12.7 in corticosteroid-treated sarcoidosis and 5.5 in comparators. The HR for T2D was 1.4 (95%CI 1.2–1.8) associated with untreated sarcoidosis and 2.3 (95%CI 2.0–3.0) associated with corticosteroid-treated sarcoidosis. The T2D risk was highest for corticosteroid-treated sarcoidosis in the first 2 years after diagnosis.ConclusionSarcoidosis is associated with an increased risk of T2D especially in older, male, corticosteroid-treated patients at diagnosis. Screening for T2D for these patients is advisable.