Question

You are now working at a clinic and a patient walks in, telling you that they have Type 2 Diabetes. Checking their chart, you realize it’s been over three years since their hemoglobin A1C plasma levels have been tested. You run a quick lab analysis and see that they have a hemoglobin A1C plasma level of 11.5%. Given this information, answer the following questions.

(A) What is A1C and how is it different from regular blood glucose measurements?

(B) How is hemoglobin A1c is formed? What cell does this occur in?

(C) What is GLUT 1 and how does it contribute to hemoglobin A1c production? What kind of process is this and does it require energy? (hint: see Chapter 10, Lipids, Membranes and Cellular Transport)

(D) What does their level of 11.5% tell you about their disease state? How does this compare to the recommended A1C levels (both diabetics and non-diabetics)

(E) At their next visit you realize that your patient’s A1C levels have not changed. What products might be forming in their blood as a result of this, and what are some of the results of having an increase of these products in their body?

Answer 1

A. The A1C test is a blood test that provides information about your average levels of blood glucose, also called blood sugar, over the past 3 months. The A1C test can be used to diagnose type 2 diabetes and prediabetes.¹The A1C test is also the primary test used for diabetes management.

A1C versus regular blood glucose measurements

Blood sugar and hemoglobin A1c are connected, but they are different, too. Your blood sugar meter measures the concentration of glucose in the bloodstream at the instant you prick your finger. The reading is in milligrams of glucose per deciliter (a tenth of a liter) of blood, abbreviated as mg/dL. Blood sugar levels vary throughout the day. In people with diabetes, they can range from below 70 mg/dL to above 200.

The hemoglobin A1c test measures the percentage of red blood cells with a sugar coating. In people without diabetes, that's only 4% to 5% of red blood cells. But in people with diabetes, who have more sugar in the bloodstream, the percentage can reach 15% or higher. The hemoglobin A1c number is a way to gauge long-term glucose control, or lack of it. Blood sugar meters can't check for hemoglobin A1c; finding that requires a trip to the doctor. The American Diabetes Association recommends that people with diabetes do this twice a year.

B. Glycated hemoglobin (hemoglobin A1c, HbA_1c, A1C, or Hb_1c; sometimes also referred to as being Hb1c or HGBA1C) is a form of hemoglobin that is measured primarily to identify the three-month average plasma glucose concentration. The test is limited to a three-month average because the lifespan of a red blood cell is four months (120 days). However, since red blood cells do not all undergo lysis at the same time, HbA1C is taken as a limited measure of three months. It is formed in a non-enzymatic glycationpathway by hemoglobin's exposure to plasma glucose.