Better Understanding Your Blood Sugar Lab Test Results

Are you worried that your blood sugar levels may be too high? What does too high mean anyway? And what tests should you have done to see what your levels are? It’s important to know your blood sugar levels, particularly if you have any of the symptoms below or a family history of blood sugar issues. Now let’s dive into the nitty gritty…

A regular screening of your blood sugar levels can be invaluable if there are abnormalities or other health concerns. It might tell you that you have: prediabetes, diabetes or gestational diabetes. These conditions often don’t have symptoms at first, so regularly screening your blood sugar by your doctor is important. 

The nuts and bolts
Blood glucose (sugar) is the main source of sugar in your blood. Whenever you eat or drink, your body breaks down carbohydrates from whatever you consume, turning it into sugar for energy. Your pancreas produces a hormone known as insulin. This helps blood sugar enter into your body’s cells. It also aids your body in storing sugar for later use. As your cells use blood sugar, both glucose and insulin levels in your blood decrease.

A1c meaning
Whether you’ve heard of A1c or HbA1c level, you may not really understand what it measures. An Hemoglobin A1c is a test that measures the amount of blood glucose (sugar) that is attached to hemoglobin. Hemoglobin is a part of your red blood cells. It transports oxygen from your lungs to the rest of your body. An A1c test tells you what the average amount of sugar attached to hemoglobin has been for about the past three months. This time period represents the typical life of a red blood cell. If your HbA1c levels are too high, then it might mean you are prediabetic or even have diabetes.

Calculating A1c is important if you have symptoms suggestive of diabetes. These include: increased thirst, urinating more frequently, blurred vision, or fatigue.

If you have anemia or other type of blood disorder, then calculating A1c may not be as accurate for diagnosing diabetes. Additionally, an hemoglobin A1c test isn’t used for gestational diabetes or when diagnosing diabetes in children. We’ll get into gestational diabetes shortly.

Gestational diabetes

Gestational diabetes is a type of diabetes that only affects pregnant women. About 2% – 10% of pregnancies in the U.S. are affected by gestational diabetes. It can occur in women who are not otherwise diabetic. The condition is caused by the body not making enough insulin during pregnancy. When pregnant, a woman’s body makes more hormones and goes through all sorts of changes. These cause the body’s cells to not use insulin as effectively. This is known as insulin resistance, and increases your body’s need for insulin. During late pregnancy, all women have some degree of insulin resistance. But, some women are insulin resistant before they become pregnant. And they may not even know it. Since they start with their pregnancies with an increased need for insulin, gestational diabetes is more likely to occur.   

Blood sugar levels
When looking at your A1c levels, these are the ranges that indicate normal blood sugar, prediabetes, and diabetes: 

  • Normal: HbA1c below 5.7%
  • Prediabetes: HbA1c between 5.7% – 6.4%
  • Diabetes: HbA1c of 6.5% or higher

When should you have your A1c levels checked?
The CDC (Centers for Disease Control) recommend that adults over 45 years of age get tested to screen for prediabetes and diabetes. If your test results come back normal, then you should repeat this test every three years. However, if your A1c levels are between 5.7% and 6.4%, then you should have them checked every one to two years. You should also think about what foods may be raising your blood sugar. These will typically be higher carbohydrate foods, particularly those without fiber. Think sugary foods.

Being under 45 years of age doesn’t necessarily mean that you shouldn’t have your blood sugar levels checked. You should get them tested if you have any of the following risk factors: overweight or obesity, elevated fasting blood glucose (see below), symptoms of insulin resistance (also see below), polycystic ovarian syndrome (a hormonal disorder among women of reproductive age where periods may be infrequent or prolonged, or who have high levels of the male hormone androgen), difficulty losing weight despite attempts to lose it, cravings for carbohydrates, etc. High blood pressure, history of heart disease and physical inactivity are other risk factors for diabetes for those under the age of 45.

Fasting blood sugar
Another lab test you can do is called fasting blood glucose, or fasting blood sugar. Unlike an A1c test, it can be used to screen for gestational diabetes. A fasting blood sugar test measures the amount of sugar in your blood after an overnight fast. It measures the amount of sugar in your blood when it should be at its lowest. This occurs in the morning after not having eaten or drank anything for at least eight hours. Water is an exception since it doesn’t contain any calories.

Fasting blood sugar ranges
The following ranges indicate different cut off points:

  • Normal: 99 mg/dL or less
  • Prediabetes: 100 – 125 mg/dL
  • Diabetes: 126 mg/dL or more

Glucose tolerance test
A glucose tolerance test is also known as an oral glucose tolerance test. It helps you identify abnormalities in how your body handles sugar after eating, and often before your fasting blood sugar becomes abnormal. This test can be used to screen for type 2 diabetes. A modified version of this test can be used to diagnose gestational diabetes. 

C-peptide test
A C-peptide test is a measure of how much C-peptide you have in your blood or urine. It’s a substance that’s made in the pancreas along with insulin. As you recall, insulin is a hormone that controls your body’s blood sugar levels. Since C-peptide and insulin are released from the pancreas at the same time and in roughly the same amounts, testing it can be a good way to measure how much insulin your body is making. Additionally, it stays in the body longer than insulin. It’s often used to differentiate type 1 from type 2 diabetes. In type 1 diabetes, your body makes very little or no insulin at all. The same is true with C-peptide, a good reflection of your insulin levels. However, in type 2 diabetes, while the body does make insulin, it doesn’t use it well. So C-peptide levels can be higher than normal. This can also indicate: insulin resistance (when the body incorrectly responds to insulin, causing your blood glucose levels to become very high), Cushing’s syndrome (a disorder where your body makes too much cortisol, the body’s main stress hormone), or a tumor of the pancreas. 

If your healthcare practitioner thinks you might have diabetes but isn’t sure whether it’s type 1 or type 2, then a C-peptide test can be helpful. If you have low blood sugar, or hypoglycemia, then this test is useful as well. Symptoms of low blood sugar include: sweating, rapid or irregular heartbeat, feeling abnormally hungry, blurred vision (a symptom of diabetes as well), confusion, or fainting.  

As you can see, there are many ways to test your blood sugar levels. When was the last time you had your blood sugar levels checked?