The goal of this observational study is to learn why some adults over the age of 65, have A1c tests that do not match up with their blood glucose levels, also known as 'A1c-glucose discordance'.

The main question it aims to answer is:

Could alternative tests like CGM or personalized A1c provide more accurate diabetes screening in this population?

Participants will be asked to perform blood tests every week to two weeks and wear a CGM for up to 8 weeks.

Inclusion Criteria:

• Age 65 years of age or older
• A1c 5.3% - 7.4% without a diagnosis on the problem list and/or current or prior treatment for diabetes
• Evidence of A1c discordance by meeting one of two criteria developed by an EHR based algorithm
• At least five (5) HbA1c values and three (3) CBC values available in the EHR in the previous 10 years
• Willingness to wear an Abbott Freestyle Libre 3 System Sensor for up to 48 days
• Willingness to consent to data collection using the electronic health record and sign a medical release to obtain future medical records from other health care facilities

Exclusion Criteria:

• Known or suspected diabetes of other causes (type 1 diabetes, pancreatogenic diabetes, monogenic diabetes, etc.)

• Clinically significant anemia based on most recent hematocrit (M = <38%, F <33%) and/or hemoglobin (M = <12 g/dL, F = <10 g/dL) within the last 12 months

• Condition with short life expectancy

• Blood (hematologic) malignancy

• rtCGM-interference agents per manufacturer (e.g., high dose vitamin C)

• Unstable psychiatric or medical condition

• Active treatment for cancer, planned treatment for cancer, or recent active cancer with a likelihood of recurrence or progression, that, in the opinion of the site investigator, would interfere with study therapy prior to 2029

  • Allowed Exceptions: Treated cancer with no evidence of disease, no evidence of disease progression, and no planned change in therapy. Examples of allowable cancers include:

    • Breast cancer stable after active treatment, managed with long-term anti-estrogen therapy
    • Prostate cancer being observed
    • Stage 0 or 1 tumors status post resection or other definitive treatment
    • Other similarly stable cancer comorbidities

Individuals 65 years of age and older, who have evidence of A1c-glucose discordance without either a diagnosis of type 2 diabetes or current/ prior treatment for type 2 diabetes