Five heterogeneous HbA1c trajectories from childhood to adulthood in youth with type 1 diabetes from three different continents: A group‐based modeling approach

Abstract

Objectives Only a fraction of youth meet established targets for glycemic control; many experience deteriorating control over time. We compared trajectories of hemoglobin A1c (HbA1c) among youth from three trans‐continental type 1 diabetes (T1D) registries and identified clinical variables associated with the odds of following increasing vs stable trajectories. Research design and methods Analyses included longitudinal data from 15 897 individuals age 8 to 18 with T1D for at least 2 years and HbA1c measurements in at least 5 years during the observation period. Cohorts were selected from Australasian Diabetes Data Network (ADDN; Australia), German/Austrian/Luxembourgian Diabetes‐Patienten‐Verlaufsdokumentation initiative (DPV; Germany/Austria/Luxembourga), and the T1D Exchange Clinic Network (T1DX; US) clinic registries. Group‐based trajectory modeling and multivariable logistic regression identified unique HbA1c trajectories and their predictors. Results Five heterogeneous trajectories of glycemic control in each registry were identified: low, intermediate, high stable; intermediate and high increasing. The overall HbA1c level for each trajectory group tended to be lowest in the DPV, higher in the ADDN, and highest in the T1DX. The absolute level of HbA1c and the proportion of individuals within each trajectory varied across registries: 17% to 22% of individuals followed an increasing trajectory. Compared with maintaining a stable trajectory, following an increasing trajectory was significantly associated with ethnic minority status, lower height z‐score, higher BMI z‐score, insulin injection therapy, and the occurrence of severe hypoglycemia; however, these factors were not consistent across the three registries. Conclusions We report the first multinational registry‐based comparison of glycemic control trajectories among youth with T1D from three continents and identify possible targets for intervention in those at risk of an increasing HbA1c trajectory.

Racial-Ethnic Inequity in Young Adults With Type 1 Diabetes

“…Our results demonstrate that the impact of diabetes technology use on glycemic control was large, even after adjustment for SES, rivaling treatment effects of new diabetes medications ( 35 ). Although prior research has highlighted racial-ethnic disparities in diabetes technology among youth with type 1 diabetes ( 36 , 37 ), our results show that racial-ethnic disparities exist despite being covered for these devices. In addition, we show that Black YA had lower diabetes technology use than Hispanic YA, despite similar public insurance coverage rates and SES levels.…”

Association between glycaemic outcome and BMI in Danish children with type 1 diabetes in 2000–2018: a nationwide population‐based study

“…In a study identifying specific trajectories of HbA 1c over age by using group‐based trajectory modelling in 7002 children with type 1 diabetes, a lower risk of high BMI was found in the low stable HbA 1c group compared to the identified intermediate stable, intermediate increasing and high stable HbA 1c groups 22 . With similar modelling in a multicentre study from Germany, Austria and the USA in more than 15 000 children aged 8–18 years, increasing HbA 1c trajectories were associated with higher BMIz compared to a low stable trajectory 23 . In line with the present study, this indicates that there is a group reaching target HbA 1c without increasing BMI.…”

Vascular Complication in Adolescents With Diabetes Mellitus

“…Sustained hyperglycaemia is associated with diabetes complications and strict glycaemic control reduces both microvascular and macrovascular complications of diabetes (61,62). It has been shown that an increasing HbA1c trajectory is associated with higher BMI, lower linear growth, use of insulin injection therapy and severe hypoglycaemic episodes (63), and poor glycaemic control early in life is associated with microvascular disease (64). Perhaps the HbA1c trajectory, not just the value, may also define risk of vascular complications and thus impact our approach.…”

“…Continuous subcutaneous insulin infusions using an insulin pump may reduce the risk of complications such as retinopathy and peripheral neuropathy (70). While it has been shown that the use of insulin pump therapy in some cohorts has been associated with improved glycaemic control (63,71), diabetes technology has not necessarily been associated with a sustained improvement in glycaemic control or reduction in complications (72). Few studies have examined glucose variability using continuous glucose monitoring and diabetes complications as the widespread availability of continuous glucose monitoring is relatively recent.…”