Marked Increases in CGM Use Has Not Prevented Increases in HbA1c Levels in Participants in the T1D Exchange (T1DX) Clinic Network
Authors: FOSTER NICOLE C. , MILLER KELLEE , DIMEGLIO LINDA , MAAHS DAVID M. , TAMBORLANE WILLIAM V. , BERGENSTAL RICHARD M. , CLEMENTS MARK A. , RICKELS MICHAEL R. , SMITH ELIZABETH , OLSON BETH A. , BECK ROY 
Published: June 2018

In this report, we examined and compared changes in diabetes technology use and HbA1c levels from data collected in 22,470 participants in the T1DX clinic registry (mean age 26±18 years, duration 14±13 years) between 2016 and 2017 with registry data collected from 25,529 participants (mean age 22±17 years, duration 10±12 years) between 2010 and 2012. There was a moderate increase in insulin pump use across all age groups from 57% in the 2010-12 cohort to 63% in the 2016-17 cohort. In contrast, continuous glucose monitoring (CGM) use rose sharply from 7% to 28%, with the most dramatic increase in the preadolescent and young child groups (4% to 35% for participants &lt;13 years old) (Table). Despite adjustments for differences in age and diabetes duration, mean HbA1c levels increased over time (from 8.2% in 2010-12 to 8.6% in 2016-17), with the greatest rise in participants 13-25 years old (Table). In both cohorts CGM users had lower HbA1c levels than non-users (7.6% in CGM users vs. 8.3% in non-users in 2010-12 and 7.9% in CGM users vs. 8.8% in non-users in 2016-17).
Conclusion: In the T1D Exchange registry, HbA1c levels have increased although HbA1c remains lower in CGM users than non-users.

Disclosure
N.C. Foster: None. K. Miller: None. L. DiMeglio: Advisory Panel; Self; Eli Lilly and Company. Research Support; Self; Dexcom, Inc., Medtronic, Sanofi, Caladrius Biosciences, Inc., Janssen Research & Development, Xeris Pharmaceuticals, Inc., Sanofi. D.M. Maahs: Advisory Panel; Self; Insulet Corporation. Consultant; Self; Abbott. Research Support; Self; Medtronic, Bigfoot Biomedical, Dexcom, Inc., Insulet Corporation, Roche Diabetes Care Health and Digital Solutions. W.V. Tamborlane: Consultant; Self; AstraZeneca, Boehringer Ingelheim GmbH, Eli Lilly and Company, Medtronic MiniMed, Inc., Novo Nordisk Inc., Sanofi, Takeda Pharmaceuticals U.S.A., Inc. R.M. Bergenstal: Research Support; Self; Johnson & Johnson Services, Inc.. Consultant; Self; Johnson & Johnson Services, Inc.. Research Support; Self; Abbott. Advisory Panel; Self; Abbott. Research Support; Self; Becton, Dickinson and Company. Consultant; Self; Becton, Dickinson and Company. Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc., AstraZeneca, Takeda Pharmaceuticals U.S.A., Inc., Dexcom, Inc.. Stock/Shareholder; Self; Merck & Co., Inc.. Research Support; Self; Eli Lilly and Company, Sanofi. Advisory Panel; Self; Sanofi, Roche Pharma. Research Support; Self; Novo Nordisk Inc.. Advisory Panel; Self; Novo Nordisk Inc.. Research Support; Self; Medtronic. Consultant; Self; Medtronic. Research Support; Self; Hygieia. Advisory Panel; Self; Hygieia, Glooko, Inc.. Research Support; Self; JAEB Center For Health Research, JDRF, National Institute of Diabetes and Digestive and Kidney Diseases. M.A. Clements: Speaker's Bureau; Self; Medtronic. Advisory Panel; Self; Glooko, Inc. M.R. Rickels: Consultant; Self; Hua Medicine, Xeris Pharmaceuticals, Inc.. E. Smith: None. B.A. Olson: None. R. Beck: Consultant; Self; Eli Lilly and Company. Research Support; Self; Abbott. Consultant; Self; Bigfoot Biomedical. Research Support; Self; Dexcom, Inc.. Consultant; Self; Insulet Corporation. Research Support; Self; Roche Diabetes Care Health and Digital Solutions. Consultant; Self; Merck & Co., Inc., Xeris Pharmaceuticals, Inc..