Diabetes Care, Vol 22, Issue 7 1022-1028, Copyright © 1999 by American Diabetes Association
Blood glucose awareness training and epinephrine responses to hypoglycemia during intensive treatment in type 1 diabetes
BT Kinsley, K Weinger, M Bajaj, CJ Levy, DC Simonson, M Quigley, DJ Cox and AM Jacobson
Section of Diabetes and Metabolism, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
OBJECTIVE: To determine the effect of blood glucose awareness training
(BGAT) on epinephrine and symptom responses to hypoglycemia in patients
with type 1 diabetes enrolled in an intensive diabetes treatment (IDT)
program. RESEARCH DESIGN AND METHODS: A total of 47 subjects with
uncomplicated diabetes (duration 9 +/- 3 years: HbA1c 9.0 +/- 1.2%;
reference range 4-6%) enrolled in a 4-month outpatient IDT program were
randomized to classes in BGAT (n = 25) (BGAT group) or cholesterol
awareness (n = 22) (control group). Subjects underwent stepped hypoglycemic
clamp studies before and at completion of IDT. Plasma glucose was lowered
from 6.7 mmol/l (baseline) to 4.4, 3.9, 3.3, 2.8, and 2.2 mmol/l over 190
min. Symptoms, counterregulatory hormones, and ability of the subject to
estimate their glucose level were assessed at each plateau. At home,
subjects used a handheld computer to first estimate and then measure and
record blood glucose levels for 70 trials over a 4-week period immediately
before IDT and again immediately following the educational intervention.
RESULTS: HbA1c decreased in both BGAT group (9.1 +/- 1.4 to 7.9 +/- 1.1%; P
< 0.001) and control group (9.0 +/- 1.1 to 7.8 +/- 0.8%; P < 0.001)
(NS between groups). Frequency of hypoglycemia (< 3.9 mmol/l) increased
in both groups, from 0.45 +/- 0.06 to 0.69 +/- 0.07 episodes per day (P
< 0.001) in the BGAT group and from 0.50 +/- 0.08 to 0.68 +/- 0.06
episodes per day (P < 0.05) in the control group NS between groups).
Epinephrine responses after IDT were greater in the BGAT group (repeated
measure analysis of variance [ANOVA], F = 3.5, P < 0.05). A separate
analysis of subjects n = 26) most at risk for hypoglycemia (HbA1c after IDT
< 7.8% or an HbA1c improvement of > 2 percentage points) showed that
frequency of hypoglycemia increased in both the groups: from 0.50 +/- 0.09
to 0.80 +/- 0.11 episodes per day (P < 0.01) in the BGAT group (n = 14)
and from 0.43 +/- 0.11 to 0.75 +/- 0.07 episodes per day (P < 0.05) in
the control group (n = 12) (NS between groups). However, the epinephrine
response in control subjects decreased with IDT while the response in the
BGAT subjects was preserved (repeated measure ANOVA, F = 4.4, P < 0.02).
CONCLUSIONS: BGAT is a useful intervention to decrease blunting of
counterregulatory responses associated with improved glycemic control and
may modify the severity of hypoglycemia associated with improved glycemic
control in type 1 diabetes.