PROSPECTIVE ASSESSMENT OF SEVERE HYPOGLYCEMIA IN DIABETIC CHILDREN AND ADOLESCENTS WITH IMPAIRED AND NORMAL AWARENESS OF HYPOGLYCEMIA

To establish whether impaired hypoglycaemic awareness is associated wi th increased rate of severe hypoglycaemia and to assess clinical predi ctors of severe episodes without warning symptoms a prospective study of 130 insulin-dependent diabetic children and adolescents was underta ken 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 clin ical and metabolic characteristics. Episodes of severe hypoglycaemia w ere recorded for 1 year. The rate of severe hypoglycaemia was higher i n the group with impaired awareness than in the group with normal awar eness (p < 0.0001). Of the severe hypoglycaemic episodes, 34.0% develo ped without warning symptoms. Patients with impaired awareness experie nced more severe episodes without warning symptoms than those with nor mal awareness (p = 0.0054). Severe hypoglycaemia occurred more frequen tly in patients with impaired awareness aged 6 years and less (p = 0.0 041) than in older counterparts. Impaired awareness reported at baseli ne [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 th an 5% of home blood glucose readings 3.3 mmol/l or less in the precedi ng month (4.2; p = 0.0211) proved to be independently predictive of se vere hypoglycaemic events without warning symptoms. In conclusion, imp aired hypoglycaemic awareness is associated with an increased rate of severe hypoglycaemia in diabetic children and adolescents. One third o f severe episodes developed without warning symptoms. Impaired awarene ss, young age and recent biochemical or severe hypoglycaemias are inde pendent risk factors for such episodes. Avoidance of hypoglycaemia sho uld be a priority in preschool children with diabetes.