Blood Sugar Tests: Do You Really Need A HbA1c Test?

Q: Blood Sugar Tests: Do You Really Need A HbA1c Test?

Hello： Based on your blood glucose report, you are currently in a prediabetic state. <br>It is recommended that you maintain a healthy diet and engage in moderate exercise, and follow up with the family medicine clinic in three months. <br>The quantity of food you consume can aff

Diabetes testing

Hello, doctor.
Recently, I've been experiencing excessive sweating in my upper body and my wounds are healing slowly.
Since my mother has diabetes, I suspect I might have it too.
I went to a large local hospital's endocrinology department to get a blood test.
I told the doctor that I wanted to check my HbA1c and my postprandial blood sugar levels two hours after eating.
However, the doctor said that just testing the postprandial blood sugar was sufficient and that the HbA1c test was unnecessary.
I thought the HbA1c test would be more accurate, but the doctor insisted on doing the postprandial test first.
The result came back at 142 mg/dL, and the doctor said congratulations, since it was below 200, I do not have diabetes, and then sent me on my way.
I feel uneasy about this, so I would like to ask the doctor a few questions:
1.
According to online information, the normal maximum standard for postprandial blood sugar is 140 mg/dL.
Since my result was 142, is that considered elevated? The doctor said that as long as it is below 200, there is no issue, but isn't that the standard for random blood sugar levels?
2.
On the day of the blood test, I was running out of time, so I only ate half of my usual lunch before going to the hospital.
Does this affect the accuracy of the 142 result? Does the amount of food consumed impact postprandial blood sugar levels?
3.
Is a postprandial blood sugar level of 142 truly reassuring as the doctor said, indicating that I do not have diabetes and do not need to check my HbA1c, or could this indicate that I am already in a prediabetic stage?

A Cheng, 30~39 year old female. Ask Date: 2022/12/01

Dr. Hou Angting reply Family Medicine

Hello: Based on your blood glucose report, you are currently in a prediabetic state.
It is recommended that you maintain a healthy diet and engage in moderate exercise, and follow up with the family medicine clinic in three months.
The quantity of food you consume can affect your blood glucose levels, so avoiding overeating will help with blood sugar control.
Wishing you good health.

Reply Date: 2022/12/01

More Info

Understanding blood sugar tests is crucial, especially for individuals with a family history of diabetes or those experiencing symptoms that may suggest glucose metabolism issues. In your case, you have raised several important questions regarding your recent blood sugar test results and the necessity of an HbA1c test.

1. Postprandial Blood Sugar Levels: You mentioned that your postprandial (after meal) blood sugar level was 142 mg/dL. According to the American Diabetes Association (ADA), a normal postprandial blood sugar level should be less than 140 mg/dL two hours after eating. Therefore, a reading of 142 mg/dL does indeed exceed the normal threshold, which could indicate impaired glucose tolerance. However, the physician's reassurance that you are not diabetic because your reading is below 200 mg/dL is based on the diagnostic criteria for diabetes. A blood sugar level of 200 mg/dL or higher during a glucose tolerance test or a random blood sugar test indicates diabetes. Your reading, while slightly elevated, does not meet the criteria for diabetes but suggests that you may be at risk for developing it, particularly given your family history.

2. Impact of Meal Size on Blood Sugar Levels: The amount and type of food consumed before a blood sugar test can significantly affect the results. Eating a smaller meal can lead to lower blood sugar levels post-meal compared to a regular-sized meal. However, it is essential to maintain a consistent eating pattern when monitoring blood sugar levels to ensure accurate comparisons over time. If you typically eat a larger meal, a smaller meal could lead to a misleadingly low reading. Therefore, it is advisable to follow your usual dietary habits before testing to get a more accurate reflection of your blood sugar response.

3. Need for HbA1c Testing: The HbA1c test measures your average blood sugar levels over the past two to three months and is a critical tool for diagnosing and monitoring diabetes. While your postprandial blood sugar of 142 mg/dL does not confirm diabetes, it does suggest that further monitoring is warranted. The HbA1c test can provide additional context regarding your overall glucose control and help identify if you are in the prediabetic range (HbA1c of 5.7% to 6.4%). Given your family history and current symptoms, it would be prudent to discuss with your healthcare provider the possibility of undergoing an HbA1c test to assess your long-term blood sugar levels.

In summary, while your postprandial blood sugar level is slightly elevated, it does not confirm diabetes but indicates a potential risk. The physician's advice to monitor your blood sugar is sound, but considering your family history and symptoms, an HbA1c test would provide valuable information regarding your glucose metabolism over time. It is essential to maintain open communication with your healthcare provider about your concerns and to follow up with appropriate testing to ensure your health is monitored effectively.

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