Lab Tests Related to Diabetes

*Please note that reference ranges are set by individual laboratories for their specific populations and vary accordingly. Therefore, a discussion of your specific testing results with your healthcare provider is recommended.

Diagnosing Diabetes

Fasting Plasma Glucose (FPG): This test measures your fasting blood sugar (glucose) levels, meaning what your blood sugar levels are after you have not eaten or drank anything (except water) in the last eight hours. This test is important because it can indicate if you have diabetes or prediabetes. Typical reference ranges* for individuals without diabetes are less than 100 mg/dl. Levels* between 100 mg/ dl to 125 mg/dl may indicate prediabetes, and greater than 126 mg/ dl may indicate diabetes

Hemoglobin A1c (HBA1C): This test measures your Hemoglobin A1c level, the average level of glucose (blood sugar) in your blood, by determining how much glucose is bound to your red blood cells. This test is important because it shows how well diabetes is being managed. Typical reference ranges* for both children and adults it is less than 6%. If A1c levels are higher than 7%, it may indicate diabetes; levels between 5.7-6.4% are considered to potentially be prediabetes.

Oral Glucose Tolerance (OGTT): This test analyzes how your body processes sugar and is conducted before and two hours after you drink a specific sweet drink. This test is important because it can indicate if you have Type 2 or gestational diabetes. Typical levels* for non-diabetic individuals are less than 140 mg/dl; levels that may indicate that you have prediabetes are between 140 mg/dl to 199mg/ dl; and levels that indicate that you may have diabetes are 200 mg/ dl or higher.

Random/Casual Plasma Glucose: This test is used to check blood glucose levels throughout the day and before meals, usually in relation to taking medications for diabetes. Random glucose should not be interpreted without the advice and care of a doctor or nurse.

Glycated Serum Protein (GSP): This test measures the amount of glucose that is attached to the total serum proteins. This test is important because it indicates the average amount of blood sugar (glucose) in the last 2-3 weeks. GSP is also known as fructosamine. Typical reference range* is between 175-280 mmol/L for nondiabetic individuals, between 210-421 mmol/L for controlled diabetes, and between 268-870 mmol/L for uncontrolled diabetes.

Monitoring Cholesterol and other Lipids (Fats)

Lipid Panel (LP): This test measures the fats and fatty substances used by your body as a source of energy called lipids. Lipids include cholesterol, high-and low-density lipoprotein, and triglycerides. This test is important because it indicates your chances of developing cardiovascular disease.

Ask Your Doctor

• How often are A1Cs drawn?
• What is an A1C range you recommend I try to achieve?
• What other body systems will be monitored via lab testing?
• How frequently will kidney function, thyroid function, and/or cholesterol be monitored?
• Should I fast before my test? If so, how long should I fast before the test?
• Do I need a c-peptide or autoantibody test to help understand my diabetes?

Monitoring Kidney Function

Blood Urea Nitrogen (BUN): This test measures the amount of nitrogen in your blood. This test is important because higher levels can indicate kidney issues. A typical reference range* for adults is between 7-20 mg/dL, through the ranges can vary based on your age.

Creatinine: This test measures the level of creatine in your blood. Normally, kidneys filter our creatine, which is a waste product created through the metabolism of both the muscle and of certain foods. This test is important because higher levels of creatine can indicate an issue with your kidneys. A typical reference range* for adults is between 0.84 and 1.21 mg/dL.

Creatinine Clearance: This test measures how much creatinine your kidneys filter. Through this test, creatine levels from your blood and your urine are compared. This test is important because it indicates how well the kidneys are functioning. *Please note that the reference range for creatinine depends on a person’s age, sex, body and muscle mass, etc.

Comprehensive Metabolic Panel (CMP): This test includes the components of a Basic Metabolic Panel (BMP) plus the below additional measures related to liver activity and function.

Cystatin C: This test measures how well your kidneys are working by measuring the amount of cystatin C that is retained in your blood. Because it is a small molecule, it is normally passed in urine. High levels of cystatin C in your blood indicates that your kidneys are not working well. Typical reference ranges* are between 0.6-1.3 mg/dl.

Glomerular Filtration Rate (GFR): This test detects how well kidneys are working by measuring the flow of filtered blood through the kidneys. A typical reference range* for adults is between 90-120 mL/ min/1.73m2.

Microalbumin: This test measures the presence of small amounts (hence, “micro”) of albumin in the urine, which is a protein found in blood serum. Albumin is the main protein of blood plasma and it helps bind other minerals and hormones. When kidneys start to fail, a small amount of albumin begins to leak through which this test can detect. A typical reference range* for adults is less than 30 mg. The ratio of this protein to creatinine in urine is used by your doctor to understand your kidney function.