How Low Should You Go?

As anyone who has read the scientific literature or who has watched any of the numerous advertisements on television knows, the goal for people with diabetes is to decrease their hemoglobin A1c (HbA1c) value. Written only in the fine print is the serious risk of hypoglycemia that can result when trying to achieve this goal.

In Sunday’s special session, “How Low Is Too Low? Hemoglobin A1c Considerations in Diabetes Management,” a panel including a laboratorian, a clinician, and a patient discussed the issues around tight glycemic control and the drive to achieve a low HbA1c value.

Moderator Dr. Daniel Holmes discussed how the laboratory community can aid clinicians in focusing not solely on the number the lab produces, but in treating the patient. Strictly adhering to HbA1c guidelines can be problematic in certain patient populations, including elderly and isolated patients, and this was exacerbated by the pandemic. “Just because a study shows something, doesn’t mean you don’t still have to keep the individual person in mind,” Holmes noted.

Dr. Irl Hirsch of the University of Washington Medicine Diabetes Institute gave the clinician’s perspective on tight glycemic control and HbA1c. By setting broad goals that aren’t specific to each patient, more harm than can good can be the outcome, he warned. “A1c targets have been associated with both good and, unfortunately, bad outcomes,” he said. “A1c is a powerful metric for a population, but not necessarily for an individual.”

Hirsch advocated for greater reliance on continuous glucose monitoring (CGM) data with a focus on the amount of time a patient spends in the correct range of blood glucose concentration, referred to as time in range (TIR). “The data show that the greater the time in range, the lower the risk of complications,” he emphasized.

Hirsch has a unique insight on the issue of diabetes care, as the third speaker was his brother, James Hirsch. James has had Type I diabetes for most of his life and shared his firsthand experience with the challenge of trying to meet an HbA1c goal. “It’s almost as if your blood sugar becomes a proxy for your character,” he said. “It’s important to understand that when you are doing poorly at controlling your diabetes, you are not failing. Your blood sugar is just a number that is used to improve your health.”

In some ways, Holmes said, the laboratory is a victim of its own success with the accuracy and standardization of HbA1c testing. While guidelines are important for directing treatment, each individual needs customized treatment in order to have the best outcomes possible. “Protocol might drive care, but the clinical picture of the patient should always win.”