As a clinical pharmacist, people with diabetes will rely on your help to tailor A1c goals and decipher continuous glucose monitoring (CGM) metrics. Continue to emphasize individualizing glycemic goals, explain that a “one-size-fits-all” approach isn’t safe, practical, or recommended...
A1c. Rely on A1c to assess average glucose over 2 to 3 months. Good evidence links meeting A1c goals with better microvascular outcomes. Stick with an A1c target below 7% for most people with diabetes and few comorbidities, or possibly less than 6.5% in younger, healthier patients who can safely reach this goal. But relax A1c goals for some patients, since risk of hypoglycemia may outweigh benefits of tighter glucose control. For example, consider an A1c goal under 7.5% to 8% for those with multiple comorbidities or long-standing diabetes, or an even looser goal for frail older patients with dementia, nursing home residents, etc. Reassess A1c targets periodically based on factors such as new or worsening comorbidities, life expectancy, and your patient’s preferences.
CGM. If patients use a CGM, focus on key metrics to fill in blanks that A1c doesn’t provide, such as glucose lows, highs, or variability. Identify the time in range (TIR), the amount of time patients are in their sweet spot, such as 70 to 180 mg/dL. In this case, advise aiming for a TIR above 70%, if A1c goal is below 7%. Increase TIR by first reducing time BELOW range to limit hypoglycemia. A reasonable goal is less than 4% below 70 mg/dL and avoiding time under 54 mg/dL.
Review glucose variability to see how widely glucose swings. For example, aim for a coefficient of variation (CV) of 36% or less. And check the glucose management indicator (GMI). It’s a rough A1c prediction, based on an average of about 14 days of readings. For example, a mean glucose of 175 mg/dL works out to a GMI of 7.5%. Use the GMI for a “sneak peek” of how recent med or lifestyle changes will impact A1c results if the patient continues on the same track. Also assess the percentage of time CGM is active, aim for at least 70% over a 14-day period for CGM metrics to be the most reliable.
REFERENCES
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American Diabetes Association Professional Practice Committee. 6. Glycemic Goals and Hypoglycemia: Standards of Care in Diabetes-2024. Diabetes Care. 2024;47(Suppl 1):S111-S125. Available at: https://diabetesjournals.org/care/article/47/Supplement_1/S111/153951/6-Glycemic-Goals-and-Hypoglycemia-Standards-of
American Diabetes Association Professional Practice Committee. 13. Older Adults: Standards of Care in Diabetes-2024. Diabetes Care. 2024;47(Suppl 1):S244-S257. Available at: https://diabetesjournals.org/care/article/47/Supplement_1/S244/153944/13-Older-Adults-Standards-of-Care-in-Diabetes-2024
Battelino T, Danne T, Bergenstal RM, et al. Clinical Targets for Continuous Glucose Monitoring Data Interpretation: Recommendations From the International Consensus on Time in Range. Diabetes Care. 2019;42(8):1593-1603. Available at: https://diabetesjournals.org/care/article/42/8/1593/36184/Clinical-Targets-for-Continuous-Glucose-Monitoring