Diabetes Care, Vol 21, Issue 8 1330-1338, Copyright © 1998 by American Diabetes Association
Effect of glycemic control on glucose counterregulation during hypoglycemia in NIDDM
CJ Levy, BT Kinsley, M Bajaj and DC Simonson
Joslin Diabetes Center, Boston, Massachusetts, USA.
OBJECTIVE: We examined the effect of glycemic control of NIDDM on
counterregulatory hormone responses to hypoglycemia and compared the effect
with that seen in patients with IDDM. RESEARCH DESIGN AND METHODS: Eleven
subjects with NIDDM and eight age- and weight-matched control subjects and
ten subjects with IDDM and ten age- and weight-matched control subjects
were studied. All subjects underwent a stepped
hypoglycemic-hyper-insulinemic clamp study during which plasma glucose
levels were lowered in a stepwise manner from 5.0 to 2.2 mmol/l in steps of
0.6 mmol/l every 30 min. Counterregulatory hormones (epinephrine,
norepinephrine, glucagon, ACTH, cortisol, and growth hormone [GH]) were
measured, and a symptom survey was administered during the last 10 min of
each 30-min interval. RESULTS: The threshold for release of epinephrine,
norepinephrine, ACTH, and cortisol occurred at higher plasma glucose levels
in NIDDM than in IDDM patients (P < 0.05-0.01). The glucose threshold
for release of epinephrine and norepinephrine correlated with glycemic
control as measured by glycosylated hemoglobin (P < 0.05-0.01). However,
for a given level of glycemic control, the threshold for release of
epinephrine and norepinephrine occurred at a higher glucose level in NIDDM
versus IDDM patients (P < 0.05-0.01). At the nadir level of
hypoglycemia, glucagon, ACTH, and cortisol levels were all higher in NIDDM
compared with IDDM subjects, whereas GH levels were lower. CONCLUSIONS:
Glycemic control alters counterregulatory responses to hypoglycemia in
NIDDM as has been previously reported in IDDM. However, at similar levels
of glycemic control, NIDDM patients release counterregulatory hormones at a
higher plasma glucose level than patients with IDDM. In addition, subjects
with NIDDM maintain their glucagon response to hypoglycemia. These data
suggest that patients with NIDDM may be at reduced risk of severe
hypoglycemia when compared with a group of IDDM patients in similar
glycemic control, thus providing a more favorable risk-benefit ratio for
intensive diabetes therapy in NIDDM.