Anti-insulin antibody test
Insulin antibodies – serum; Insulin Ab test; Insulin resistance – insulin antibodies; Diabetes – insulin antibodies
The anti-insulin antibody test checks to see if your body has produced antibodies against insulin.
Antibodies are proteins the body produces to protect itself when it detects anything “foreign,” such as a virus or transplanted organ.
How the Test is Performed
A blood sample is needed.
How to Prepare for the Test
No special preparation is necessary.
How the Test will Feel
When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.
Why the Test is Performed
This test may be performed if:
- You have or are at risk for type 1 diabetes
- You appear to have an allergic response to insulin
- Insulin no longer seems to control your diabetes
Normal Results
Normally, there are no antibodies against insulin in your blood.
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your health care provider about the meaning of your specific test results.
What Abnormal Results Mean
If you have IgG and IgM antibodies against insulin, your body reacts as if the insulin in your body is a foreign protein that needs to be removed. This may make insulin less effective, or not effective at all. This is because the antibody prevents the insulin from working the right way in your cells. As a result, your blood sugar can be unusually high.
The antibodies can also prolong the effect of insulin by releasing some insulin long after your meal has been absorbed. This can put you at risk for low blood sugar.
If the test shows a high level of IgE antibody against insulin, your body has developed an allergic response to the insulin. This could put you at risk for skin reactions where you inject insulin. You can also develop more severe reactions that affect your blood pressure or breathing.
Other medicines, such as antihistamines or low-dose injectable steroids, may help to lessen the reaction. If reactions have been severe, you may need a treatment process called desensitization.
Risks
Veins and arteries vary in size from one person to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks of having blood drawn are slight but may include:
- Excessive bleeding
- Fainting or feeling lightheaded
- Hematoma (blood building up under the skin)
- Infection (a slight risk any time the skin is broken)
Insulin C-peptide test
C-peptide
C-peptide is a product that is created when the hormone insulin is produced and released into the body. The insulin C-peptide test measures the amount of this product in the blood.
How the Test is Performed
A blood sample is needed.
How to Prepare for the Test
Preparation for the test depends on the reason for the C-peptide measurement. Ask your health care provider if you should not eat (fast) before the test. Your provider may ask you to stop taking medicines that can affect the test results.
How the Test will Feel
When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.
Why the Test is Performed
C-peptide is measured to tell the difference between insulin the body produces and insulin someone injects into their body.
Someone with type 1 or type 2 diabetes may have their C-peptide level measured to see if their body is still producing any insulin. It may also be measured in cases of low blood sugar to see if the person’s body is producing too much insulin.
Normal Results
A normal result 0.5 to 2.0 nanograms per milliliter (ng/mL).
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.
People with type 2 diabetes, obesity, and insulin resistance may have a high C-peptide level that is normal for them.
What Abnormal Results Mean
C-peptide level is based on blood sugar level. C-peptide is a sign that your body is producing insulin. A low level (or no C-peptide) indicates that your pancreas is producing little or no insulin.
- A low level may be normal if you have not eaten recently. Your blood sugar and insulin levels would naturally be low then.
- A low level is abnormal if your blood sugar is high and your body should be making insulin at that time.
Risks
Veins and arteries vary in size from one person to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
- Bleeding
- Fainting or feeling lightheaded
- Hematoma (blood buildup under the skin)
- Infection (a slight risk any time the skin is broken)
