Objective: To report the population burden of hypoglycemia necessitating emergency medical services (EMS) and the long-term outcomes in patients with type 1 diabetes mellitus (T1DM) receiving different insulin treatments.
Methods: We retrieved all EMS calls because of hypoglycemia in patients with T1DM in Olmsted County, Minnesota, between January 1, 2003, and December 31, 2009, and reviewed the related medical records.
Results: During the 7-year study period, 531 EMS calls were made involving 208 patients with T1DM (112 men, 96 women; mean age 47 ± 13 years). Of the 208 patients, 137 (66%) were receiving multiple daily insulin (MDI) injections, 50 (24%) were receiving continuous subcutaneous insulin infusion, 15 (7%) were receiving simple insulin (SI), 4 (2%) were treated with metformin + MDI, and 2 (1%) were not receiving treatment for diabetes (after pancreas transplantation). The last 2 groups were excluded from further analysis because of small sample size. The remaining 3 treatment groups differed by age (P<.02), with the oldest patients receiving SI. Repeated calls, emergency department transportation (EDT), and hospitalization had a 33%, 49%, and 18% frequency, respectively, and did not differ among the treatment groups. In a multivariate model, mortality was significantly associated with treatment type (the SI group had a higher risk for mortality than did the MDI group [P = .03] after exclusion of 27 patients who changed treatment during follow-up), age (P<.0001), and EDT (P = .04).
Conclusion: The population burden of EMS-requiring hypoglycemia in patients with T1DM is high. Medical resource utilization was similar among the 3 treatment groups. Mortality was higher in the SI group (limited by small sample size) and among patients requiring EDT and increased with advancing age. Further research could be directed toward understanding the effect of expert evaluation of high-risk patients on long-term outcomes.