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

Published: August 9, 2026Updated: August 16, 2026

This test measures your average blood sugar levels over the past 2–3 months and checks how well your kidneys filter creatinine from your urine. It’s often used to monitor diabetes management and kidney function together.

Quick summary

["Helps track blood sugar control and kidney health in one combined test."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
51642-7
Short code
HL Retics NFr
Synonyms
HL Retics NFr
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Matters for Blood Sugar Control

HbA1c reflects your blood sugar levels over time, giving doctors a clearer picture than daily glucose checks alone. It’s a key tool for adjusting diabetes treatment plans to keep your levels stable.

How Your Kidneys Work with This Test

Creatinine clearance measures how well your kidneys filter waste from your blood. The urine sample helps assess kidney function alongside your HbA1c, as both tests can be affected by kidney disease.

What to Expect Before the Test

You’ll collect a 24-hour urine sample (starting and ending at the same time) to measure creatinine. Your doctor may also provide a fingerstick blood test for HbA1c. Follow any specific instructions to ensure accurate results.

What the Results Mean

HbA1c results (typically reported as a percentage) show your average blood sugar over months. Creatinine clearance results (usually in mL/min) indicate kidney function. Both values help determine if your diabetes treatment needs adjustment.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HbA1c + 24-hour urine creatinine

Frequently asked questions

Why do I need both HbA1c and creatinine clearance together?
This combined test provides a fuller picture of your health. HbA1c focuses on blood sugar, while creatinine clearance assesses kidney function. Together, they help prevent complications like nerve damage or heart disease.
Can I eat or drink normally before collecting my urine sample?
Yes, but avoid excessive fluids or foods that might affect creatinine levels (like high-protein meals). Follow your lab’s specific instructions for the best results.
What if my creatinine clearance is lower than expected?
A lower creatinine clearance may indicate kidney issues, which could affect how your body processes medications or fluids. Your doctor will discuss next steps, possibly including further kidney tests or adjustments to your diabetes treatment.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy