Improvement in A1c levels in early adulthood in the T1D Exchange: Impact of racial, socioeconomic, and clinical factors.

CONTEXT Glycemic control in adolescents with type 1 diabetes is poor; yet, it typically improves during early adulthood. Factors related to improvement of glycemic control are unclear. OBJECTIVE Examine how demographic and clinical variables may impact trajectories of glycemic control over time. DESIGN Retrospective observational. SETTING T1D Exchange clinic registry. PATIENTS OR OTHER PARTICIPANTS A total of 1,775 participants ages 18-30 years at enrollment. MAIN OUTCOME MEASURES Latent class trajectory modeling was used to determine sub-groups following a similar HbA1c trajectory over time. RESULTS Five distinct trajectories of HbA1c classes were identified: "low-decline" and "moderate-decline" Groups had low or moderate HbA1c with a gradual decline, the "high-stable" Group had high HbA1c and remained stable, and the "very high-rapid decline" and "very high-slow decline" Groups had very high HbA1c with rapid or gradual decline. Compared with the "high-stable" Group, the "low-decline" and "moderate-decline" Groups were more likely to be male (P=0.009), white non-Hispanic (P=0.02), non-smokers (P<0.001), check self-monitoring blood glucose (SMBG) more frequently (P<0.001), and have higher education (P<0.001), lower BMI (P=0.02), and lower daily insulin dose (P<0.001). Compared with the "very high-rapid decline" and "very high-slow decline" Groups, "low-decline" and "moderate-decline" Groups were more likely to be male (p=0.02), have higher education (p<0.001), use insulin pumps (p=0.01), be non-smokers (p<0.001), and have a higher number of SMBG checks per day at enrollment (p<0.001). CONCLUSIONS We determined 5 distinct patterns of glycemic control from early adulthood into adulthood. Further evaluation into the modifiable factors associated with a declining HbA1c trajectory would aid in the development of targeted interventions.