Diabetes, Vol 40, Issue 3 358-363, Copyright © 1991 by American Diabetes Association
Independent effects of youth and poor diabetes control on responses to hypoglycemia in children
TW Jones, SD Boulware, DT Kraemer, S Caprio, RS Sherwin and WV Tamborlane
Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06510.
To evaluate the effects of childhood and poorly controlled
insulin-dependent diabetes mellitus (IDDM) on counterregulatory hormone and
symptomatic responses to hypoglycemia, we studied 16 nondiabetic children
(13 +/- 2 yr), 19 nondiabetic adults (26 +/- 3 yr), and 13 children with
IDDM (14 +/- 2 yr, HbA, 15.1 +/- 3.3%) during a gradual reduction in plasma
glucose with the glucose-clamp technique. Plasma glucose was reduced from
approximately 5 to approximately 2.8 mM over 240 min with serial assessment
of counterregulatory hormone levels and symptom awareness. The plasma
glucose level that triggered a sustained rise in plasma epinephrine was
consistently higher in nondiabetic children than in adults (3.9 +/- 0.06
vs. 3.2 +/- 0.06 mM, P less than 0.001). Poorly controlled IDDM further
elevated the glucose threshold for epinephrine release to normoglycemic
levels (4.9 +/- 0.2 mM, P less than 0.001 vs. both control groups). Age and
IDDM also produced an upward shift in the glucose level at which growth
hormone release and symptom awareness were initiated. In contrast to the
effect on glucose thresholds, maximal epinephrine responses and symptom
scores were increased only by age and not IDDM (2-fold higher in children).
We conclude that childhood and poor diabetes control independently
contribute to an upward shift in glucose thresholds for counterregulatory
hormone release and symptom awareness during mild hypoglycemia.
Normoglycemic counterregulation may interfere with efforts to control
diabetes in young patients.