title: REPLACE-BG: A Randomized Trial Comparing Continuous Glucose Monitoring With and Without Routine Blood Glucose Monitoring in Adults With Well-Controlled Type 1 Diabetes.
abstract: To determine whether the use of continuous glucose monitoring (CGM) without confirmatory blood glucose monitoring (BGM) measurements is as safe and effective as using CGM adjunctive to BGM in adults with well-controlled type 1 diabetes (T1D).
  
  
  
  A randomized noninferiority clinical trial was conducted at 14 sites in the T1D Exchange Clinic Network. Participants were ≥18 years of age (mean 44 ± 14 years), had T1D for ≥1 year (mean duration 24 ± 12 years), used an insulin pump, and had an HbA1c≤9.0% (≤75 mmol/mL) (mean 7.0 ± 0.7% [53 ± 7.7 mmol/mol]); prestudy, 47% were CGM users. Participants were randomly assigned 2:1 to the CGM-only (n= 149) or CGM+BGM (n= 77) group. The primary outcome was time in range (70-180 mg/dL) over the 26-week trial, with a prespecified noninferiority limit of 7.5%.
  
  
  
  CGM use averaged 6.7 ± 0.5 and 6.8 ± 0.4 days/week in the CGM-only and CGM+BGM groups, respectively, over the 26-week trial. BGM tests per day (including the two required daily for CGM calibration) averaged 2.8 ± 0.9 and 5.4 ± 1.4 in the two groups, respectively (P< 0.001). Mean time in 70-180 mg/dL was 63 ± 13% at both baseline and 26 weeks in the CGM-only group and 65 ± 13% and 65 ± 11% in the CGM+BGM group (adjusted difference 0%; one-sided 95% CI -2%). No severe hypoglycemic events occurred in the CGM-only group, and one occurred in the CGM+BGM group.
  
  
  
  Use of CGM without regular use of confirmatory BGM is as safe and effective as using CGM with BGM in adults with well-controlled T1D at low risk for severe hypoglycemia.
authors.affiliation: Northwestern University, Chicago, IL.
authors.forename: Grazia
authors.initials: G
authors.lastname: Aleppo
authors.affiliation: Jaeb Center for Health Research, Tampa, FL.
authors.forename: Katrina J
authors.initials: KJ
authors.lastname: Ruedy
authors.affiliation: Jaeb Center for Health Research, Tampa, FL t1dstats5@jaeb.org.
authors.forename: Tonya D
authors.initials: TD
authors.lastname: Riddlesworth
authors.affiliation: Henry Ford Health System, Detroit, MI.
authors.forename: Davida F
authors.initials: DF
authors.lastname: Kruger
authors.affiliation: Keck School of Medicine of the University of Southern California, Los Angeles, CA.
authors.forename: Anne L
authors.initials: AL
authors.lastname: Peters
authors.affiliation: University of Washington School of Medicine, Seattle, WA.
authors.forename: Irl
authors.initials: I
authors.lastname: Hirsch
authors.affiliation: Park Nicollet International Diabetes Center, Minneapolis, MN.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Bergenstal
authors.affiliation: Joslin Diabetes Center, Boston, MA.
authors.forename: Elena
authors.initials: E
authors.lastname: Toschi
authors.affiliation: Harold Schnitzer Diabetes Health Center at Oregon Health & Science University, Portland, OR.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Ahmann
authors.affiliation: Barbara Davis Center for Childhood Diabetes, Aurora, CO.
authors.forename: Viral N
authors.initials: VN
authors.lastname: Shah
authors.affiliation: University of Pennsylvania Perelman School of Medicine, Philadelphia, PA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Rickels
authors.affiliation: Atlanta Diabetes Associates, Atlanta, GA.
authors.forename: Bruce W
authors.initials: BW
authors.lastname: Bode
authors.affiliation: Scripps Whittier Diabetes Institute, La Jolla, CA.
authors.forename: Athena
authors.initials: A
authors.lastname: Philis-Tsimikas
authors.affiliation: University of Michigan, Ann Arbor, MI.
authors.forename: Rodica
authors.initials: R
authors.lastname: Pop-Busui
authors.affiliation: University of South Florida, Tampa, FL.
authors.forename: Henry
authors.initials: H
authors.lastname: Rodriguez
authors.affiliation: University of South Florida, Tampa, FL.
authors.forename: Emily
authors.initials: E
authors.lastname: Eyth
authors.affiliation: Iowa Diabetes and Endocrinology Research Center, Des Moines, IA.
authors.forename: Anuj
authors.initials: A
authors.lastname: Bhargava
authors.affiliation: Jaeb Center for Health Research, Tampa, FL.
authors.forename: Craig
authors.initials: C
authors.lastname: Kollman
authors.affiliation: Jaeb Center for Health Research, Tampa, FL.
authors.forename: Roy W
authors.initials: RW
authors.lastname: Beck
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis*; D015190:Blood Glucose Self-Monitoring; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007332:Insulin Infusion Systems; D008297:Male; D008875:Middle Aged; D012959:Socioeconomic Factors; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin