Hemoglobin A1c (HbA1c) with 24-hour urine collection for creatinine adjustment

Why This Test Is Done

Doctors order this test to check how well your diabetes is controlled over time. Unlike a single blood sugar reading, HbA1c reflects your average blood sugar levels from the last 2–3 months, helping identify trends and adjust treatment plans if needed. Adjusting for creatinine ensures the result reflects your true blood sugar status, even if your kidney function varies.

How the Test Works

Your blood is drawn to measure hemoglobin that carries oxygen, specifically the portion bound to glucose (HbA1c). The 24-hour urine sample includes creatinine, a waste product from muscle metabolism, to normalize the HbA1c result for kidney function. This adjustment helps account for differences in kidney processing across individuals.

What the Results Mean

Results are typically reported as a percentage. A lower percentage suggests better long-term blood sugar control, while a higher percentage may indicate poorer control and could prompt lifestyle or treatment changes. Normal ranges vary by lab, but values often fall between 4%–6%. Adjustments for creatinine help ensure the result is accurate regardless of kidney health.

Common Reasons for Testing

This test is commonly used for people with diabetes to monitor progress, detect complications early, or adjust medications. It may also be used in pre-diabetes screening or during pregnancy to assess blood sugar trends.