Glycemic control in adolescents with type 1 diabetes (T1D) is poor; however, it typically improves during early adulthood. Factors related to improvement of glycemic control are unclear. A total of 1,775 participants aged 18-30 years at enrollment in the T1D Exchange Registry followed for an average of 6 years were included in this analysis. Latent class trajectory modeling was used to determine sub-groups following a similar HbA1c trajectory over time. Five distinct trajectories of HbA1c classes were identified: Groups 1 and 2 had low or moderate HbA1c with a gradual decline with age, Group 3 had high HbA1c and remained stable, and Groups 4 and 5 had very high HbA1c with rapid or gradual decline (Figure). Compared with Group 3, Groups 1 and 2 were more likely to be male (P = 0.01), white non-Hispanic (P = 0.02), non-smokers (P = 0.001), check glucose more frequently (P < 0.001), and have higher education (P < 0.001), lower BMI (P = 0.01), and lower daily insulin dose (P < 0.001); if female, those in Group 1 were more likely to have a pregnancy during the time observed (P = 0.04). Group 4 was more likely to increase number of SMBG checks (P = 0.02) and have BMI increase over time (P = 0.02) compared with Group 5. We determined 5 distinct patterns of glycemic control from young adulthood into adulthood. Further evaluation into the modifiable factors associated with a declining A1c trajectory would aid in the development of targeted interventions.


E. Toschi: None. R. Bailey: None. K. Miller: None. P. Calhoun: Stock/Shareholder; Self; Dexcom, Inc.


The Leona M. and Harry B. Helmsley Charitable Trust (G-2016PG-T1D053)

Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. More information is available at