Impaired awareness of hypoglycemia in a population-based sample of children and adolescents with type 1 diabetes

  1. Trang T. Ly, MBBS1,
  2. Patricia H. Gallego, MD, MSc1,
  3. Elizabeth A. Davis, FRACP1,2 and
  4. Timothy W. Jones, FRACP, MD (Tim.Jones{at}health.wa.gov.au)1,2
  1. 1Department of Endocrinology and Diabetes, Princess Margaret Hospital for Children, Perth, Western Australia, Australia
  2. 2Telethon Institute for Child Health Research, Centre for Child Health Research, The University of Western Australia, Perth, Western Australia, Australia

    Abstract

    Objective: To determine the prevalence and clinical associations of impaired awareness of hypoglycemia in a population-based sample of children and adolescents with type 1 diabetes.

    Research Design and Methods: A validated questionnaire was administered to 656 patients with type 1 diabetes over a six-month period to determine hypoglycemia awareness status. Case ascertainment was 79% of the clinic population. The rate of severe hypoglycemia (SH) was determined by data collected prospectively in the preceding year.

    Results: Impaired awareness of hypoglycemia was present in 29% of patients. Patients with impaired awareness of hypoglycemia had an earlier onset of diabetes (p<0.001), were younger (p<0.001), had lower mean levels of A1C since diabetes onset (p=0.006) and at their last visit (p=0.001). The overall rate of SH was 24.5 episodes/100 patient-years, in the preceding year. The SH rate was higher in those with impaired awareness of hypoglycemia (37.1 vs. 19.3 episodes/100 patient-years, p<0.001). Among patients aged below 6 years (n=46), 59% of care providers reported impaired awareness of hypoglycemia and the rate of SH was significantly higher in those reporting impaired awareness (33.3 vs. 5.2 episodes/100 patient-years, p=0.02). More patients with recurrent hypoglycemia reported impaired awareness of hypoglycemia (47% vs 28%, p=0.03).

    Conclusions: A significant proportion of children and adolescents with type 1 diabetes have impaired awareness of hypoglycemia. Screening for impaired awareness is an important component of routine diabetes care and can identify patients at increased risk of a severe hypoglycemic event.

    Footnotes

      • Received March 19, 2009.
      • Accepted July 1, 2009.

    This Article

    1. Diabetes Care
    1. All Versions of this Article:
      1. dc09-0541v1
      2. 32/10/1802 most recent