HbA1c is a valuable metric for comparing treatment groups in a randomized trial, for assessing glycemic trends in a population over time, or for cross-sectional comparisons of glycemic control in different populations. However, what is not widely appreciated is that HbA1c may not be a good indicator of an individual patient’s glycemic control because of the wide range of mean glucose concentrations and glucose profiles that can be associated with a given HbA1c level. To illustrate this point, we plotted mean glucose measured with continuous glucose monitoring (CGM) versus central laboratory–measured HbA1c in 387 participants in three randomized trials, showing that not infrequently HbA1c may underestimate or overestimate mean glucose, sometimes substantially. Thus, if HbA1c is to be used to assess glycemic control, it is imperative to know the patient’s actual mean glucose to understand how well HbA1c is an indicator of the patient’s glycemic control. With knowledge of the mean glucose, an estimated HbA1c (eA1C) can be calculated with the formula provided in this article to compare with the measured HbA1c. Estimating glycemic control from HbA1c alone is in essence applying a population average to an individual, which can be misleading. Thus, a patient’s CGM glucose profile has considerable value for optimizing his or her diabetes management. In this era of personalized, precision medicine, there are few better examples with respect to the fallacy of applying a population average to a specific patient rather than using specific information about the patient to determine the optimal approach to treatment.

Helmsley Charitable Trust.

Fourteen days of CGM data provide a good estimation of glucose metrics for a 3-month period.

The demographics of T2D in youth indicate significant social vulnerability which may affect outcomes. Metformin and insulin were the initial treatment in most youth. Importantly, T2D may occur at younger ages than previously thought and should be considered in all high-risk children presenting with diabetes.

Objective To identify determinants of HbA1c levels one year after the diagnosis of type 1 diabetes (T1D) in participants in the Pediatric Diabetes Consortium (PDC) T1D New Onset (NeOn) Study. Research Design and Methods Diabetes-specific as well as socioeconomic factors during the first year following diagnosis were analyzed in 857 participants (mean age 9.1 years, 51% female, 66% non-Hispanic White) not participating in an intervention study who had an HbA1c value at 12 months. Results Mean ± SD HbA1c at one year was 62 ± 16 mmol/mol (7.8% ± 1.5). In univariate and multivariate analyses, clinical center, non-Hispanic White race, private health insurance, living with both parents, higher frequency of self-monitoring of blood glucose (SMBG), and lower insulin requirements were associated with lower HbA1c concentrations at one year (p<0.01). No association was found with gender, age, Tanner stage, BMI, DKA at onset, number of positive autoantibodies or HbA1c at onset, or number of visits to diabetes physician during the first year. Conclusions White race, higher socioeconomic status, two-parent household, more frequent SMBG and low insulin requirements are associated with lower HbA1c concentration one year after the onset of T1D in children.