While poor glycemic control is a well-established risk factor for mortality and MACE in T1D, specific patterns of control over time have not been well-studied. Thus, we sought to identify long-term trajectories of HbA1c and examine associated participant characteristics, mortality, and MACE incidence in the Pittsburgh Epidemiology of Diabetes Complications (EDC) study, a prospective observational cohort with childhood-onset (<17 years) T1D. These data were analyzed as part of a DNA methylation sub-study (currently in progress), where n=422 (baseline mean T1D duration 21 yrs, 53% male) have been followed for outcomes, including 28-year mortality and MACE. Beginning in 1988, HbA1c was measured at baseline, 2, 4, 6, 8, 15, and 22 yrs. HbA1c trajectories were identified using latent class growth modeling. Five HbA1c trajectories were identified (Figure). There were no significant differences in age, T1D duration, age at T1D onset, sex, education, or insulin dose between groups. Both mortality and MACE were significantly increased in IMPROVED (p<0.02) and even more so in HIGH (p<.0001) compared to LOW. MODERATE and WORSENED did not have increased risk of either outcome compared to LOW. These results demonstrate that, despite improvement, past high HbA1c remains associated with increased long-term mortality and MACE risk in this T1D cohort.


R.G. Miller: None. T. Costacou: None. T.J. Orchard: None.


American Diabetes Association (1-19-JDF-109 to R.G.M.)

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