HbA1c, DKA Peak in Adolescence and Subsequently Decrease Among Individuals With T1D

New research published by the American Diabetes Association suggests the hyperglycemia and diabetic ketoacidosis (DKA) associated with type 1 diabetes (T1D) in adolescence are peaks of trends that begin around age 9 and partially improve during their 30s.

These findings were published in Diabetes Care, and indicate the need for innovative ways to optimize glycemia from late childhood, through adolescence, and into early adulthood.

For young people with T1D, adolescence is linked to less utilization of health care services, heightened hyperglycemia, and increased risk of hospitalization due to DKA. With this in mind, the study authors sought to investigate age-relate changes in HbA_1c measurement and levels, as well as hospitalization rates for DKA during childhood, adolescence, and early adulthood.

The study included 93,125 individuals with T1D aged between 5 and 30 years, all from the United Kingdom. Data were obtained from the National Diabetes Audit and/or the National Paediatric Diabetes Audit for England and Wales, covering 2017 to 2020.

During childhood, occurrence of unreported HbA_1c measurements is infrequent. However, among 19-year-olds in the study, the rate of unreported measurements was 22.3% for men and 17.3% for women, later decreasing to 17.9% and 13.1%, respectively, by the time they reach age 30.

“The sudden increase at ages 17 to 19 years in the proportion of people with no annual records of HbA_1c suggests that attendance at either a pediatric clinic, a general practitioner led diabetes service, or an adult hospital-based clinic dramatically reduces at the time of changing service provision from pediatric to adult,” the authors noted. “This is also a time when psychological and social pressures are increasing.

In the study, the median (IQR) HbA_1c level for 9-year-old boys was 7.6% or 60 mmol/mol (7.1-8.4%; 54-68 mmol/mol). For girls of the same age, median HbA_1c level was 7.7% or 61 mmol/mol (8.0-8.4%; 64-68 mmol/mol). At age 19, these levels increased to 8.7% (7.5-10.3%) for young men and 8.9% (7.7-10.6%) for young women. At age 30, they then slightly declined to 8.4% (7.4-9.7%) for men and 8.2% (7.3-9.7%) for women.

The rate of hospitalization for DKA was shown to steadily increase with age. This started at age 6, with a hospitalization rate of 2.0% for boys and 1.4% for girls, and peaked at 19 years for men (7.9%) and 18 years for women (12.7%).

By age 30, rates decreased to 4.3% for men and 5.4% for women. The authors also found that, among individuals aged 9 years and older, prevalence of DKA is consistently higher among girls and women.

There are several limitations worth noting. First, the data may not include individuals who are at the highest risk but not actively engaged with health services, and incomplete records of HbA_1c measurements—particularly from specialist services—may have lead to an underrepresentation of certain data.

“While it is not known for certain, it is likely that, on average, nonattenders have high HbA_1c,” the authors said. “This means that the scale of the increase in HbA_1c in the late teenage years and early twenties may well be even greater than we report.”

Additionally, the availability of hospital admission data is limited to England, excluding admissions in Wales. Although the cohort includes 5% of individuals from Wales, the age-related patterns of hospitalization are expected to be similar. Lastly, the association between deprivation and health outcomes may vary by age, and the geographic location of young adults as they transition to independent living may not accurately reflect their experiences and health risks.

However, the study benefits from the extensive coverage of the UK population, the integration of data from multiple sources, and the statistical power provided by the sequential cohorts approach.

Overall, this study's findings indicate that both HbA_1c levels and DKA occurrence rise during adolescence and subsequently decrease. Notably, the measurement of HbA_1c—which serves as an indicator of clinical assessment—sharply drops in the late teenage years.

Additionally, the rates of significantly elevated HbA_1c levels exceeding 10% (>86 mmol/mol) reached their highest point for about a third of the study population, and during this period, about a fifth of the group did not have their HbA_1c levels recorded.

According to the authors, these results highlight the necessity for age-specific services to address these challenges for individuals with T1D.

“The overall aims should be to flatten the rise in HbA_1c throughout the teenage years, which are independent of duration of diabetes, ethnicity, and social deprivation, and to reduce the peak in hospital admissions for DKA across the same ages,” the authors concluded. “Further evidence on the type of interventions and service structures that will address these issues is needed, but it is clear that improved, innovative, and appropriately resourced age-appropriate service designs oriented to the delivery of optimal care during this period of life are warranted.”

Reference

Holman N, Woch E, Dayan C, et al. National trends in hyperglycemia and diabetic ketoacidosis in children, adolescents, and young adults with type 1 diabetes: a challenge due to age or stage of development, or is new thinking about service provision needed? Diabetes Care. Published online May 22, 2023. doi:10.2337/dc23-0180