A nationwide population-based study on the risk of coma, ketoacidosis and hypoglycemia in patients with celiac disease and type 1 diabetes.

AIMS: Celiac disease (CD) may influence metabolic control in type 1 diabetes (T1D). This work examines whether CD in T1D influences hospital admissions due to coma, ketoacidosis and hypoglycemia.

METHODS: In population-based cohort study, individuals with CD were identified using biopsy data (1969-2008) from Sweden's 28 pathology departments. T1D was defined as a recorded diagnosis of T1D at age ≤30 years in the Swedish National Patient Register between 1964 and 2009. In total, 906 individuals had both T1D and CD and were matched for sex, age and calendar period with 4303 reference individuals. Through stratified Cox regression analysis, we modeled CD as a time-dependent covariate and estimated the risk of future coma, ketoacidosis and hypoglycemia, defined by relevant international classification of disease codes among T1D patients with and without CD.

RESULTS: During follow-up, patients with both T1D and CD had 49 hospital admissions with diabetic coma, 91 episodes of ketoacidosis and 25 hypoglycemic events. Among patients with T1D, CD did not influence the risk of coma (adjusted HR 0.97; 95 % CI 0.72-1.32), ketoacidosis (adjusted HR 1.08; 95 % CI 0.86-1.34), or hypoglycemia (adjusted HR 1.34; 95 % CI 0.87-2.05). The absolute risk of coma was 621/100,000 person-years in T1D and CD (637 in controls). Corresponding figures for ketoacidosis were 1175/100,000 person-years in T1D and CD (1092 in controls) and for hypoglycemia 316/100,000 person-years (236 in controls). HRs for metabolic emergencies in T1D were similar in the first 5 years after T1D diagnosis as thereafter.

CONCLUSIONS: Having a diagnosis of CD is unlikely to influence the risk of coma, ketoacidosis and hypoglycemia in T1D patients.