Incidence and trends in hypoglycemia hospitalization in adults with type 1 and type 2 diabetes in England, 1998-2013:A retrospective cohort study

Objective: To determine trends in hospitalization for hypoglycemia in adults with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) in England. Research Design and Methods: Adults with T1DM or T2DM were identified from 398 of the 684 practices within the Clinical Practice Research Datalink, for which linkage to the Hospital Episode Statistics was possible. Hypoglycemia as the primary reason for hospitalization between 1998 and 2013 was extracted. Trends were estimated using joinpoint regression models for adults with T1DM, young and middle-aged adults with T2DM (18-64 years), and elderly adults with T2DM (≥65 years), respectively. Results: Among 23,246 adults with T1DM, 1,591 hypoglycemia hospitalizations occurred during 121,262 person-years. Among 241,441 adults with T2DM, 3,738 hypoglycemia hospitalizations occurred during 1,344,818 person-years. In adults with T1DM, the incidence increased 3.74% (95% CI 1.70-5.83) annually from 1998 to 2013. In young andmiddle-aged adults with T2DM, the annual incidence increase was 4.12% (0.61-7.75) from 1998 to 2013. In elderly adults with T2DM, the incidence increased 8.59% (5.76-11.50) annually from 1998 to 2009, and decreased 8.05% (214.48 to 21.13) annually from 2009 to 2013, but the incidence was still higher in 2013 than 1998 (adjusted rate ratio 3.01 [1.76-5.14]). Trends in HbA1c level did not parallel trends of hypoglycemia hospitalization for both diabetes types. A possible reason for declined hypoglycemia trend in 2009-2013 in elderly adults with T2DM may be continuously decreased sulfonylurea use after 2009, which was not seen in young and middle-aged adults with T2DM. Conclusions: Hypoglycemia requiring hospitalization has been an increasing burden in adults with T1DM and T2DM in England in the previous two decades, with the exception of the decline in elderly adults with T2DM starting in 2009.