Diabetes Care, Vol 18, Issue 1 17-26, Copyright © 1995 by American Diabetes Association
Differential regulation of counterregulatory hormone secretion and symptoms during hypoglycemia in IDDM. Effect of glycemic control
BT Kinsley, B Widom and DC Simonson
Department of Medicine, Joslin Diabetes Center, Boston, MA 02215.
OBJECTIVE--To determine 1) if there was a differential effect of glycemic
control on individual counterregulatory hormone responses to hypoglycemia
in patients with insulin-dependent diabetes mellitus (IDDM), 2) whether
these modifications affect hypoglycemic symptom perception, and 3) if there
was a level of glycemic control below which counterregulatory and
symptomatic responses to hypoglycemia become consistently altered. RESEARCH
DESIGN AND METHODS--We performed hypoglycemic clamp studies on 38 patients
with IDDM and 38 healthy control subjects. Glucose was lowered from 5.0 to
2.2 mmol/l over 3 h in decrements of 0.6 mmol/l each 30 min. Epinephrine,
cortisol, growth hormone (GH), glucagon, and symptom score were measured at
each glucose plateau. RESULTS--In IDDM patients, HbA1 levels were
positively correlated with incremental epinephrine (r = 0.58, P < 0.001)
and cortisol (r = 0.52, P < 0.01) responses, but inversely correlated
with GH responses (r = -0.31, P < 0.05). The increase in symptom score
correlated with the epinephrine response in the IDDM patients (r = 0.57, P
< 0.001), but not in the healthy control subjects (r = -0.02, NS). In
IDDM patients with HbA1 < or = 7.8% (n = 7), the epinephrine, cortisol,
and symptomatic responses to hypoglycemia were blunted, but GH secretion
was preserved. CONCLUSIONS--These data suggest that 1) there is
differential regulation of counterregulatory hormone secretion that is
dependent on the level of glycemic control, 2) epinephrine is an important
determinant of symptom perception in IDDM patients, but not in healthy
control subjects, and 3) multiple defects in counterregulatory hormone
secretion and symptom perception are consistently observed in patients with
HbA1 levels < or = 7.8%.