Summaryhvvodycemic, it is inevitably difficult and not without risk.The acute response to simulated hypoglycemia induced by 2-deoxyglucose (2DG) was compared with the prolonged fasting test as a possible screening test for detection of childhood hypoglycemia. Ten children, ages 2-9 yr, without a documented history of hypoglycemia were classified retrospectively as reference subjects. While fasting, their plasma glucose decreased to an average of 50 mg/dl (range, 30-74) between 28-36 h. After infusion of 2DG, 50 mg/kg IV over 30 min, their plasma glucose increased by an average of 35 mg/dl (range, 19-56) between 60-120 min. The half-life of plasma 2DG was 48 min.Twenty-three other children in the same age range had an abnormal response to one or both of these tests. Thirteen of these children became definitely hypoglycemic while fasting (glucose < 30 mg/dl) and also failed to increase their plasma glucose by more than 10 mg/dl after 2DG. Five children had plasma glucose values between 30-40 mg/dl during the first 24 h of fasting that were associated with a change in mental status but responded to 2DG with an increase in plasma glucose. The remaining five subjects had an apparently normal response to fasting but did not respond to 2DG; two of these had documented spontaneous hypoglycemia. No cases of documented hypoglycemia were undetected by either test. It is concluded that the 2DG test is a short safe supplement to fasting which is equally effective as the prolonged fasting test in detecting hypoglycemia. Neither test alone is completely reliable, but the combination is complementary.
AbbreviationThe most direct approach to confirming a suspected diagnosis of spontaneous hypoglycemia is to measure blood glucose at the time of symptoms and, if possible, to demonstrate that symptoms are rapidly relieved after the blood glucose has been increased. This obvious approach is very often not successful in children because hypoglycemia is typically sporadic, brief, and may not be associated with definitive symptoms. When blood glucose values are obtained they may be equivocal. For these reasons, follow-up testing is frequently required to establish or confirm the diagnosis of hypoglycemia.Hypoglycemia in children due to various etiologies commonly occurs while fasting, and therefore fasting has been the most widely recommended general screening test (4, 10). If properly conducted, observations made during the fasting test can lead to a specific differential diagnosis in the event that the child does become hypoglycemic; however, as a test procedure, fasting has several practical disadvantages. Because the test may need to be continued for as long as 36 h or until the child becomes definitely ----~nter~retation may be compiicated by choice of appropriate reference standards and a variable relationship between blood glucose and symptoms (16). An especially frustrating outcome is to find that some children with documented spontaneous fasting hypoglycemia may fail to be distinguished from normal children under conditions ...