Longitudinal Trajectories of Metabolic Control From Childhood to Young Adulthood in Type 1 Diabetes From a Large German/Austrian Registry: A Group-Based Modeling Approach

OBJECTIVE Worsening of glycemic control in type 1 diabetes during puberty is a common observation. However, HbA1c remains stable or even improves for some youths. The aim is to identify distinct patterns of glycemic control in type 1 diabetes from childhood to young adulthood. RESEARCH DESIGN AND METHODS A total of 6,433 patients with type 1 diabetes were selected from the prospective, multicenter diabetes patient registry Diabetes-Patienten-Verlaufsdokumentation (DPV) (follow-up from age 8 to 19 years, baseline diabetes duration ≥2 years, HbA1c aggregated per year of life). We used latent class growth modeling as the trajectory approach to determine distinct subgroups following a similar trajectory for HbA1c over time. RESULTS Five distinct longitudinal trajectories of HbA1c were determined, comprising group 1 = 40%, group 2 = 27%, group 3 = 15%, group 4 = 13%, and group 5 = 5% of patients. Groups 1–3 indicated stable glycemic control at different HbA1c levels. At baseline, similar HbA1c was observed in group 1 and group 4, but HbA1c deteriorated in group 4 from age 8 to 19 years. Similar patterns were present in group 3 and group 5. We observed differences in self-monitoring of blood glucose, insulin therapy, daily insulin dose, physical activity, BMI SD score, body-height SD score, and migration background across all HbA1c trajectories (all P ≤ 0.001). No sex differences were present. Comparing groups with similar initial HbA1c but different patterns, groups with higher HbA1c increase were characterized by lower frequency of self-monitoring of blood glucose and physical activity and reduced height (all P < 0.01). CONCLUSIONS Using a trajectory approach, we determined five distinct longitudinal patterns of glycemic control from childhood to early adulthood. Diabetes self-care, treatment differences, and demographics were related to different HbA1c courses.