Delaying insulin when indicated in type 2 diabetes (T2D) prolongs exposure to hyperglycemia. In the GRADE study, adults (N=5047) with T2D (duration <years, metformin monotherapy, HbA1c 6.8 to 8.5%) were randomly assigned to glimepiride, sitagliptin, liraglutide or insulin glargine U-100 and followed for mean and median of 5 years. The protocol specified addition of basal insulin glargine (non-insulin groups) or prandial insulin aspart (glargine group) ≤6 weeks after confirming the outcome of A1c>7.5%. Written consent included acceptance of injectable medications, including insulin, and to add or intensify insulin therapy after outcome confirmation. Among 2387 participants with confirmed A1c>7.5%, 834 (35.0%) added insulin within 6 weeks, 698 (29.1%) after 6 weeks, and 855 (35.8%) never. When we did a comparison by time of initiation, there were differences by age, racial group, outcome A1c and assigned treatment group. Participants never adding insulin were more likely to be older, Black/African American, or assigned to glargine. Those who added insulin were more likely to have higher confirmation A1cs or be assigned to sitagliptin. Analyses to explore investigator and participant factors influencing decisions to delay or not add insulin despite suboptimal glucose control are underway.
C. Martin: Advisory Panel; Nevro Corp. P.A. Hollander: None. H. Krause-Steinrauf: None. N.M. Butera: None. A. Ahmann: Advisory Panel; Medtronic. C. Falck-Ytter: None. B. Fattaleh: None. M.L. Johnson: Research Support; Abbott Diabetes, Dexcom, Inc., Insulet Corporation, Jaeb Center for Health Research, Lilly, Medtronic, Novo Nordisk, Sanofi. V. Lagari: None. M.E. Larkin: None. N. Rasouli: Advisory Panel; Eli Lilly and Company, Novo Nordisk, Sanofi. Research Support; Allergan, Eli Lilly and Company, Novo Nordisk. H. Willis: Research Support; Abbott Diabetes, Sanofi.
National Institute of Diabetes and Digestive and Kidney Diseases (U01DK098246, U34-DK-088043)