Blood Sugar Levels: When to Test for Diabetes

Q: Blood Sugar Levels: When to Test for Diabetes

1. Generally, a normal fasting blood glucose level is <100 mg/dL. 2. A fasting blood glucose level between 100 mg/dL and 126 mg/dL indicates an increased risk for diabetes. 3. A fasting blood glucose level ≥126 mg/dL suggests possible diabetes. <br

Blood sugar issues

Hello, doctor.
Here are my fasting, pre-meal, and post-meal blood glucose readings from my glucose meter for September 9 and 10.

On September 9:
- Morning blood glucose: 77 (fasting, 10:00 AM), 85 (12:00 PM)
- Afternoon blood glucose: 105 (1:00 PM), 108 (3:00 PM)
- Evening blood glucose: 108 (6:00 PM), 148 (8:00 PM)
On September 10:
- Morning blood glucose: 103 (fasting, 8:40 AM), 117 (10:40 AM)
- Afternoon blood glucose: 105 (12:40 PM), 123 (2:40 PM)
- Evening blood glucose: 103 (6:45 PM), 139 (8:45 PM)
On September 11:
- Morning blood glucose: 102 (fasting, 7:50 AM), 95 (9:50 AM) (I could only measure in the morning because I had to take the glucose meter out for my mother-in-law).
Should I get a hemoglobin A1c test to check for diabetes? Is my fasting blood glucose considered abnormal? On the morning of September 11, I had one green apple, two boiled eggs, and 250 mL of lightly sweetened soy milk for breakfast.
Is it normal for my blood glucose to decrease from 102 to 95?

Xiao Lian, 20~29 year old female. Ask Date: 2015/09/11

Dr. Xiao Yongxun reply Internal Medicine

1.
Generally, a normal fasting blood glucose level is <100 mg/dL.

2.
A fasting blood glucose level between 100 mg/dL and 126 mg/dL indicates an increased risk for diabetes.

3.
A fasting blood glucose level ≥126 mg/dL suggests possible diabetes.

4.
A hemoglobin A1c (HbA1c) level ≥6.5% also indicates possible diabetes.

5.
An oral glucose tolerance test (OGTT) with a 75-gram glucose load showing a blood glucose level ≥200 mg/dL two hours after ingestion also suggests possible diabetes.

6.
Symptoms such as polyphagia, polydipsia, polyuria, weight loss, and slow wound healing, along with a random blood glucose test result ≥200 mg/dL, also indicate possible diabetes.

Based on the above statements, you likely do not have diabetes at this time.
Blood glucose levels naturally fluctuate in relation to insulin concentrations in the body, and your descriptions still reflect normal variations.
As for whether you need to undergo an HbA1c test, please first document your height, weight, exercise habits, lifestyle, sleep patterns, and dietary habits, and discuss this with your primary care physician.

Reply Date: 2015/09/11

More Info

Based on the blood sugar readings you've provided, it seems that you are closely monitoring your glucose levels, which is a great practice, especially if you have concerns about diabetes. Let's break down your situation and address your questions regarding the need for further testing, particularly the HbA1c (glycated hemoglobin) test.

Blood Sugar Levels Interpretation
1. Fasting Blood Sugar: Your fasting blood sugar levels range from 77 mg/dL to 103 mg/dL. According to the American Diabetes Association (ADA), a normal fasting blood sugar level is below 100 mg/dL. Levels between 100 mg/dL and 125 mg/dL indicate prediabetes, while a fasting blood sugar of 126 mg/dL or higher on two separate tests confirms diabetes. Therefore, your fasting levels are within the normal range, which is reassuring.

2. Postprandial Blood Sugar: Your post-meal (after eating) blood sugar levels vary from 105 mg/dL to 148 mg/dL. The ADA guidelines suggest that postprandial blood sugar levels should be less than 180 mg/dL two hours after eating. Your readings of 105 mg/dL and 117 mg/dL are normal, while the 148 mg/dL reading is slightly elevated but still within the acceptable range. The 139 mg/dL reading in the evening is also within the normal limits for postprandial glucose.

3. Variability in Blood Sugar: The fluctuations you observe throughout the day are typical. After eating, it is normal for blood sugar levels to rise, and they should ideally return to baseline levels within a couple of hours. Your breakfast of an apple, two boiled eggs, and a small amount of sweetened soy milk resulted in a drop from 102 mg/dL to 95 mg/dL, which indicates that your body is effectively managing the glucose from your meal.

Need for HbA1c Testing
Given your current blood sugar readings, there is no immediate indication of diabetes. However, the HbA1c test provides a broader picture of your blood sugar control over the past two to three months. It measures the percentage of glucose attached to hemoglobin in your red blood cells. An HbA1c level of 5.7% to 6.4% indicates prediabetes, while 6.5% or higher suggests diabetes.

Since you are actively monitoring your blood sugar and have some variability in your readings, it would be prudent to have an HbA1c test done. This test can help confirm whether your blood sugar levels are consistently within the normal range or if there are concerns that need to be addressed.

Recommendations
1. Consult Your Healthcare Provider: Discuss your blood sugar readings and your concerns with your healthcare provider. They can help interpret your results in the context of your overall health and family history.

2. Consider Lifestyle Factors: Continue to maintain a balanced diet and regular physical activity, as these are crucial in managing blood sugar levels and preventing diabetes.

3. Regular Monitoring: Keep monitoring your blood sugar levels, especially if you notice any significant changes or if you experience symptoms such as increased thirst, frequent urination, or unexplained weight loss.

4. Get Tested: Schedule an HbA1c test to get a clearer picture of your long-term blood sugar control. This will help you and your healthcare provider make informed decisions about your health.

In summary, while your current blood sugar levels appear to be within normal limits, an HbA1c test can provide valuable information about your overall glucose management. Regular monitoring and consultation with your healthcare provider will help ensure that you stay on track with your health.

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