Hemoglobin A1c (HbA1c) with 24-Hour Temperature-Adjusted Index
This test measures your average blood sugar levels over the past 2–3 months, adjusted for recent body temperature changes. It helps doctors assess long-term diabetes control.
["HbA1c reflects your blood sugar trends over time, adjusted for temperature variations to improve accuracy."]
Key facts at a glance
- LOINC
- 50989-3
- Short code
- Horowitz index temp adj BldA+IhG-Rto
- Synonyms
- Horowitz index temp adj BldA+IhG-Rto
- 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
What This Test Measures
HbA1c measures the percentage of hemoglobin molecules coated with glucose (glycated hemoglobin), which reflects your average blood sugar levels over the past 2–3 months. This test is particularly useful for people with diabetes or prediabetes to track long-term glucose control. The temperature adjustment accounts for minor fluctuations in blood viscosity due to body temperature, improving the reliability of the result.
Why It Matters in Diabetes Management
Unlike daily blood sugar checks, HbA1c gives a broader picture of your glucose management. A higher HbA1c suggests poor control, while a lower value indicates better management. Adjustments for temperature help ensure the test reflects true metabolic status rather than temporary factors.
How It’s Performed
This test uses a small blood sample (usually from your finger) collected in a lab. The sample is processed to measure glycated hemoglobin levels, with an additional calculation to account for temperature variations. Results are compared to standard reference ranges to determine your average blood sugar trends.
Common Uses and Who Needs It
Doctors use this test to diagnose diabetes, monitor treatment progress, and adjust medications. It’s especially helpful for people with type 1 or type 2 diabetes, gestational diabetes, or those at high risk for diabetes. Regular HbA1c checks help prevent complications like nerve damage or heart disease.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
HbA1c Temp-Adjusted Index
Frequently asked questions
How often should I get this test?
What do my results mean?
Can I fast before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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