Frequency of morning ketosis after overnight insulin suspension using an automated nocturnal predictive low glucose suspend system.
OBJECTIVE
To assess the effect of overnight insulin pump suspension in an automated predictive low glucose suspend system on morning blood glucose and ketone levels in an attempt to determine whether routine measurement of ketone levels is useful when a closed-loop system that suspends insulin delivery overnight is being used.


METHODS
Data from an in-home randomized trial of 45 individuals with type 1 diabetes (age range 15-45 years) were analyzed, evaluating an automated predictive low glucose pump suspension system in which blood glucose, blood ketone, and urine ketone levels were measured on 1,954 mornings.


RESULTS
One or more pump suspensions occurred during 744 of the 977 intervention nights (76%). The morning blood ketone level was ≥0.6 mmol/L after 11 of the 744 nights (1.5%) during which a pump suspension occurred and 2 of the 233 nights (0.9%) during which there was no suspension compared with 11 of 977 control nights (1.1%). The morning blood ketone level was ≥0.6 mmol/L after only 2 of 159 nights (1.3%) with a pump suspension exceeding 2 h. Morning fasting blood glucose level was not a good predictor of the presence of blood ketones.


CONCLUSIONS
Routine measurement of blood or urine ketones during use of an automated pump suspension system using continuous glucose monitoring, whether threshold based or predictive, is not necessary. Recommendations for checking ketone levels should be no different when a patient is using a system with automated insulin suspension than it is for conventional diabetes self-management.
Corresponding author: Roy W. Beck, rbeck@jaeb.org.
Roy W
RW
Beck
Dan
D
Raghinaru
R Paul
RP
Wadwa
H Peter
HP
Chase
David M
DM
Maahs
Bruce A
BA
Buckingham
D000293:Adolescent; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D002940:Circadian Rhythm / Q000502:physiology*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D007328:Insulin / Q000008:administration & dosage* / Q000627:therapeutic use*; D007332:Insulin Infusion Systems; D007659:Ketones / Q000097:blood / Q000652:urine; D007662:Ketosis / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D010045:Outpatients; D011237:Predictive Value of Tests; D015995:Prevalence; D012648:Self Care; D055815:Young Adult
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin; D007659:Ketones