Impaired Awareness of Hypoglycemia in a Population-Based Sample of Children and Adolescents With Type 1 Diabetes
- Trang T. Ly, MBBS1,
- Patricia H. Gallego, MD, MSC1,
- Elizabeth A. Davis, FRACP1,2 and
- Timothy W. Jones, FRACP, MD1,2
- 1Department of Endocrinology and Diabetes, Princess Margaret Hospital for Children, Perth, Western Australia, Australia;
- 2Telethon Institute for Child Health Research, Centre for Child Health Research, The University of Western Australia, Perth, Western Australia, Australia.
- Corresponding author: Timothy W. Jones, tim.jones{at}health.wa.gov.au.
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 6-month period to determine hypoglycemia awareness status. Case ascertainment was 79% of the clinic population. The rate of severe hypoglycemia 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), and had lower mean levels of A1C since diabetes onset (P = 0.006) and at their last visit (P = 0.001). The overall rate of severe hypoglycemia was 24.5 episodes per 100 patient-years in the preceding year. The severe hypoglycemia rate was higher in those with impaired awareness of hypoglycemia (37.1 vs. 19.3 episodes per 100 patient-years, P < 0.001). Among patients aged <6 years (n = 46), 59% of care providers reported impaired awareness of hypoglycemia, and the rate of severe hypoglycemia was significantly higher in those reporting impaired awareness (33.3 vs. 52 episodes per 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
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The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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- Received March 19, 2009.
- Accepted July 1, 2009.
- © 2009 by the American Diabetes Association.
