The effects of lowering nighttime and breakfast glucose levels with sensor-augmented pump therapy on hemoglobin A1c levels in type 1 diabetes.
OBJECTIVE
This study determined the association of continuous glucose monitoring glucose (CGM-glucose) levels at different times of the day with improvement in glycated hemoglobin (HbA1c) levels. The potential application of these data is to focus effort to improve glucose control in patients with type 1 diabetes.


METHODS
Data were analyzed from 196 patients with type 1 diabetes who were randomized to receive sensor-augmented pump therapy in the 1-year STAR 3 trial. CGM-glucose values and HbA1c levels from baseline and after 1 year were evaluated to determine associations of improvement in CGM-glucose at different times of the day with longitudinal improvement in HbA1c.


RESULTS
Improvement in HbA1c levels after 1 year was related to improvement in mean CGM-glucose levels in daytime (6 a.m.-midnight), overnight (midnight-6 a.m.), and each mealtime period (P<0.0001 for each). In multivariable analysis, only improvement in breakfast meal period was associated with improvement in HbA1c after 1 year, explaining 59% of the HbA1c improvement using the partial R(2) test. Moreover, among those patients who only improved CGM-glucose in the overnight period there was an associated improvement in breakfast meal period CGM-glucose of 26 ± 22 mg/dL (P<0.01).


CONCLUSIONS
Breakfast period glucose improvement had the greatest effect on lowering HbA1c levels in patients with type 1 diabetes. Improving glucose control overnight resulted in subsequent improvement in the breakfast period. Although glucose control should be improved at all times, methods to improve overnight and post-breakfast glucose levels may be of primary importance in improving glucose control in patients with type 1 diabetes.
1 Barbara Davis Center for Childhood Diabetes , Aurora, Colorado.
David M
DM
Maahs
H Peter
HP
Chase
Emily
E
Westfall
Robert
R
Slover
Suiying
S
Huang
John J
JJ
Shin
Francine R
FR
Kaufman
Laura
L
Pyle
Janet K
JK
Snell-Bergeon
D000293:Adolescent; D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism*; D015190:Blood Glucose Self-Monitoring / Q000379:methods*; D062408:Breakfast; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000188:drug therapy*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000008:administration & dosage*; D007332:Insulin Infusion Systems; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D013997:Time Factors; D055815:Young Adult
D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007328:Insulin; C517652:hemoglobin A1c protein, human