How to Lower Your Dementia Risk: Key Lifestyle Factors Beyond Blood Tests

Hemoglobin A1c, commonly known as HbA1c or glycated hemoglobin, is a crucial blood test that measures average blood sugar levels over the past two to three months. This test works by detecting the percentage of hemoglobin proteins in red blood cells that have glucose attached to them. Since red blood cells live for approximately three months, the HbA1c test provides a long-term picture of blood sugar control, unlike daily glucose tests that only show blood sugar levels at a single point in time.

The HbA1c test is primarily used to diagnose diabetes and prediabetes, and to monitor how well people with diabetes are managing their condition. For diagnosis, an HbA1c level below 5.7 percent is considered normal, a level between 5.7 and 6.4 percent indicates prediabetes, and a level of 6.5 percent or higher on two separate tests indicates diabetes. For people already diagnosed with diabetes, the test helps determine if treatment plans are working effectively. Most adults with diabetes should aim for an HbA1c level below 7 percent, though individual targets may vary based on age, overall health, and other factors.

The test requires a simple blood sample, which can be drawn at any time of day without fasting. This convenience makes it easier for patients compared to fasting glucose tests. The sample is typically collected from a vein in the arm, though some point-of-care devices can use a finger-stick sample for immediate results. Healthcare providers usually recommend testing HbA1c at least twice a year for people with diabetes who are meeting treatment goals, or more frequently for those whose treatment has changed or who are not meeting their targets.

Several factors can affect HbA1c results and should be considered when interpreting the test. Conditions that affect red blood cell lifespan, such as anemia, recent blood loss, or blood transfusions, can lead to inaccurate results. Certain hemoglobin variants, more common in people of African, Mediterranean, or Southeast Asian descent, may also interfere with some testing methods. Additionally, pregnancy, kidney failure, and liver disease can influence HbA1c levels. If any of these conditions are present, healthcare providers may use alternative tests or interpret results differently to ensure accurate assessment of blood sugar control.