Prospective assessment of severe hypoglycaemia in diabetic children and adolescents with impaired and normal awareness of hypoglycaemia

Abstract

The goal of the treatment for Type I (insulin-dependent) diabetes mellitus is to achieve near-normal glycaemia as early as possible in as many patients as is safely possible. Hypoglycaemia is the most common and dangerous side effect of insulin treatment and the prevalence of severe episodes remains a major obstacle in attempts to prevent long-term diabetic complications with intensive insulin therapy. The Diabetes Control and Complications Trial has recently shown that intensification of insulin therapy increases threefold the risk of severe hypoglycaemia in adolescent and adult Type I patients [1,2]. Undesirable consequences of hypoglycaemia are particularly important in children, and primarily in young children, because severe hypoglycaemic events may impair normal brain development and neuropsychologic functioning [3,4,5,6]. The perception of symptoms of hypoglycaemia (hypoglycaemia awareness) is the first line of defence mechanisms against blood glucose decline: it alerts the patient to the early development of Diabetologia (1998) Summary To establish whether impaired hypoglycaemic awareness is associated with increased rate of severe hypoglycaemia and to assess clinical predictors of severe episodes without warning symptoms a prospective study of 130 insulin-dependent diabetic children and adolescents was undertaken for 1 year. Using a structured questionnaire, 48 patients reported impaired awareness and 82 reported normal awareness of hypoglycaemia at baseline of the study. The two groups did not differ regarding clinical and metabolic characteristics. Episodes of severe hypoglycaemia were recorded for 1 year. The rate of severe hypoglycaemia was higher in the group with impaired awareness than in the group with normal awareness (p < 0.0001). Of the severe hypoglycaemic episodes, 34.0 % developed without warning symptoms. Patients with impaired awareness experienced more severe episodes without warning symptoms than those with normal awareness (p = 0.0054). Severe hypoglycaemia occurred more frequently in patients with impaired awareness aged 6 years and less (p = 0.0041) than in older counterparts. Impaired awareness reported at baseline [adjusted odds ratio (OR): 5.8; p = 0.0021], age 6 years or less (3.4; p = 0.0121), previous severe episode (4.8; p = 0.0043) and more than 5 % of home blood glucose readings 3.3 mmol/l or less in the preceding month (4.2; p = 0.0211) proved to be independently predictive of severe hypoglycaemic events without warning symptoms. In conclusion, impaired hypoglycaemic awareness is associated with an increased rate of severe hypoglycaemia in diabetic children and adolescents. One third of severe episodes developed without warning symptoms. Impaired awareness, young age and recent biochemical or severe hypoglycaemias are independent risk factors for such episodes. Avoidance of hypoglycaemia should be a priority in preschool children with diabetes. [Diabetologia (1998) 41: 898±903]

Impaired Awareness of Hypoglycemia in a Population-Based Sample of Children and Adolescents With Type 1 Diabetes

“…Our rates of impaired awareness of hypoglycemia are consistent with those in a previous study reported by Barkai et al (13). In this prospective study of 130 children and adolescents with type 1 diabetes, impaired awareness was reported by 37% of patients.…”

Repetitive Hypoglycemia in Young Rats Impairs Hippocampal Long-Term Potentiation

“…Approximately two thirds of the three hypoglycemic events produce blood glucose Ͻ 35 mg/dL, and only one of 56 hypoglycemic animals died. Second, there is evidence that counter-regulatory responses to hypoglycemia may be impaired in diabetic children, especially those who experience hypoglycemia (27). Autonomic ganglion blockade simulates impairment of counter-regulatory response to hypoglycemia.…”

Predictors of Acute Complications in Children With Type 1 Diabetes

“…5,31 The presence of previous episodes may help to identify patients at greater risk for developing acute complications. 23,34 Acute complications in children with type 1 diabetes increase directly and indirectly 25,35 the costs of care. Direct medical care charges associated with DKA episodes represent 28% of the direct medical care charges for all patients, and 56% for those with recurrent DKAs.…”