Blood glucose awareness training and epinephrine responses to hypoglycemiaduring intensive treatment in type 1 diabetes

OBJECTIVE - To determine the effect of blood glucose awareness training (BG AT) on epinephrine and symptom responses to hypoglycemia in patients with t ype 1 diabetes enrolled in an intensive diabetes treatment (IDT) program. RESEARCH DESIGN AND METHODS - A total of 47 subjects with uncomplicated dia betes (duration 9 +/- 3 years, HbA(1c) 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 comp letion 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 h ormones, and ability of the subject to estimate their glucose level were as sessed at each plateau, At home, subjects used a handheld computer to first estimate and then measure and record blood glucose levels for 70 trials ov er a 4-week period immediately before IDT and again immediately following t he educational intervention. RESULTS - HbA(1c) 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) i n the BGAT group and horn 0.50 +/- 0.08 to 0.68 +/- 0.06 episodes per day ( P < 0.05) in the control group (NS between groups). Epinephrine responses a fter IDT were greater in the BGAT group (repeated measure analysis of varia nce [ANOVA], F = 3.5, P < 0.05). a separate analysis of subjects (n = 26) m ost at risk for hypoglycemia (HbA(1c), after IDT <7.8% or an HbA(1c) improv ement of >2 percentage points) showed that frequency of hypoglycemia increa sed in both the groups: from 0.50 +/- 0.09 to 0.80 +/- 0.11 episodes per da y (P < 0.01) in the BGAT soup (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 g roups). However, the epinephrine response in control subjects decreased wit h IDT while the response in the BGAT subjects was preserved (repeated measu re ANOVA, F = 4.4, P < 0.02). CONCLUSIONS - BGAT is a useful intervention to decrease blunting of counter regulatory responses associated with improved glycemic control and may modi fy the severity of hypoglycemia associated with improved glycemic control i n type 1 diabetes.