Reduction in duration of hypoglycemia by automatic suspension of insulin delivery: the in-clinic ASPIRE study.
BACKGROUND
The efficacy of automatic suspension of insulin delivery in induced hypoglycemia among subjects with type 1 diabetes was evaluated.


METHODS
In this randomized crossover study, subjects used a sensor-augmented insulin pump system with a low glucose suspend (LGS) feature that automatically stops insulin delivery for 2 h following a sensor glucose (SG) value ≤70 mg/dL. Subjects fasted overnight and exercised until their plasma glucose (measured with the YSI 2300 STAT Plus™ glucose and lactate analyzer [YSI Life Sciences, Yellow Springs, OH]) value reached ≤85 mg/dL on different occasions separated by washout periods lasting 3-10 days. Exercise sessions were done with the LGS feature turned on (LGS-On) or with continued insulin delivery regardless of SG value (LGS-Off). The order of LGS-On and LGS-Off sessions was randomly assigned. YSI glucose data were used to compare the duration and severity of hypoglycemia from successful LGS-On and LGS-Off sessions and to estimate the risk of rebound hyperglycemia after pump suspension.


RESULTS
Fifty subjects attempted 134 sessions, 98 of which were successful. The mean±SD hypoglycemia duration was less during LGS-On than during LGS-Off sessions (138.5±76.68 vs. 170.7±75.91 min, P=0.006). During LGS-On compared with LGS-Off sessions, mean nadir YSI glucose was higher (59.5±5.72 vs. 57.6±5.69 mg/dL, P=0.015), as was mean end-observation YSI glucose (91.4±41.84 vs. 66.2±13.48 mg/dL, P<0.001). Most (53.2%) end-observation YSI glucose values in LGS-On sessions were in the 70-180 mg/dL range, and none was >250 mg/dL.


CONCLUSIONS
Automatic suspension of insulin delivery significantly reduced the duration and severity of induced hypoglycemia without causing rebound hyperglycemia.
Barbara Davis Center for Childhood Diabetes, Aurora, Colorado, USA. satish.garg@ucdenver.edu
Satish
S
Garg
Ronald L
RL
Brazg
Timothy S
TS
Bailey
Bruce A
BA
Buckingham
Robert H
RH
Slover
David C
DC
Klonoff
John
J
Shin
John B
JB
Welsh
Francine R
FR
Kaufman
D000293:Adolescent; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D018592:Cross-Over Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007003:Hypoglycemia / Q000097:blood / Q000139:chemically induced / Q000517:prevention & control*; D007004:Hypoglycemic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D007328:Insulin / Q000008:administration & dosage* / Q000009:adverse effects; D007332:Insulin Infusion Systems; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000295:instrumentation* / Q000379:methods; D016896:Treatment Outcome; D055815:Young Adult
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin