Making Sense of Your Diabetes Lab Tests

After a routine appointment, your health care provider doctor hands you a requisition for a full panel of diabetes lab tests. These include HbA1c, creatinine, eGFR, LDL cholesterol, ALT, and a urine albumin-to-creatinine ratio. What does it all mean? While each test checks for something different, they are all designed to answer important questions about whether your diabetes is affecting other parts of the body.

These tests are reviewed below.

1. A1c (also called HbA1c or hemoglobin A1c): Your three-month blood sugar average

A1c is the most familiar diabetes blood test. It estimates your average blood glucose over the past 2 to 3 months.

For most nonpregnant adults with diabetes, an A1c below 7% is a common goal, although your personal target may be higher or lower depending on your overall health.

A1c results are reported as a percent that reflects the average glucose level. An A1c of 7% corresponds to an average blood glucose of about 8.6 mmol/L over the last 3 months.

The A1c is not the same as the blood glucose level which is reported as mmol/L. Also, two people can have the same A1c while having very different glucose patterns. This is why A1c is often most useful when considered alongside home blood sugar (glucose) or continuous glucose monitor (CGM) data.

2. Creatinine and eGFR: How your kidneys are doing

Diabetes can damage the kidneys over time, often without causing any symptoms.  Creatinine is a blood test that measures how well your kidneys are working. It is sometimes accompanied by an eGFR (estimated glomerular filtration rate). In general, a lower creatinine and a higher eGFR mean better kidney health. An eGFR persistently below 60 mL/min/1.73 m² can indicate kidney disease. Most importantly, if kidney damage is present, good glucose and blood pressure control plus several drugs can prevent worsening.

3. Urine albumin-to-creatinine ratio: Are your kidneys leaking albumin?

This test requires a urine sample rather than a blood sample. It looks for albumin, a protein that normally stays in your bloodstream. An albumin-to-creatinine ratio below 3 mg/mmol is considered normal. A result of 3 mg/mmol or higher can indicate increased leakage of albumin from the kidneys.

One abnormal result does not necessarily mean there is kidney disease. But persistently high levels usually do suggest kidney disease. Once again, good glucose and blood pressure control plus several drugs can prevent worsening.

4. Cholesterol: What is your heart risk?

The lipid panel usually includes LDL (“bad” cholesterol), HDL (“good” cholesterol), triglycerides, and total cholesterol.

Why check cholesterol if you have diabetes? Because diabetes increases the risk of heart attacks and strokes, and higher LDL levels mean a higher risk. There is no single “normal” LDL number that applies to everyone with diabetes. Your cholesterol results help your healthcare team discuss whether lifestyle changes, medications such as a statin, or another cholesterol-lowering drug is the best way for you to lower this risk.

5. Liver tests: More than just the liver

You may also see liver enzymes such as ALT on your bloodwork. This is sometimes requested because fatty liver (also called metabolic dysfunction-associated steatotic liver disease, or MASLD), is common in people with type 2 diabetes.

The big picture

It can be tempting to look at your bloodwork and focus on whichever number is highlighted in red. But one abnormal result does not tell the whole story.

Think of your diabetes bloodwork as a dashboard. Your A1c tells you about glucose control. Your eGFR and urine albumin tell you about your kidneys. Your cholesterol helps assess cardiovascular risk. Liver tests can provide clues about metabolic liver disease.

Understanding your bloodwork and why they’re important can help you and your healthcare team identify the best ways to protect your health for years to come.

About the author

Yifan Yang

Yifan is an endocrinology fellow at McMaster University who is passionate about making complex medical information easier to understand and apply in everyday life. Her interest include patient education, lifestyle approaches to diabetes management and caring for people with diabetes during pregnancy.