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    What causes fluctuations in blood glucose levels?

Posted on Wed, 16 Aug 2017 in Diabetes
Question: I had fasting plasma glucose test late last year at 97. Several days ago I was curious and bought myself a glucose meter over the counter here in the US. I consumed quite a few candies and carbs the day and night before I tested myself in the next morning.
The very first reading was 105 then i tried again 2-3 second later and it dropped to 94. I felt it was not right then I decided to buy the 2nd meter that day.
Next morning, I tried 2 meters at the same time, the 1st one I bought was at 92 and the new one read at 110. I was kinda panic and confused because I don't have family with diabetes history and I am a very physically active playing soccer 5-6 days a week and at least an hour each and I thought I've been doing not very bad consuming carbs.
2 days in a row I tested 2 hours after meal, 1 of them came back less than 100 and one was 112. For 3 hours after meals, they mostly came back at 96-98 and 1 time it was at 102. My questions are:

1. Today, 1 hour after a large dinner with high carb (I meant to try), I walk about 30 minutes and tried again at 2 hours. the reading was 98. Did the short walk cause the reading to go to normal range?

2. At 2 hours 45 minutes, I tried again, it shot up to 112, 15 minutes later, it went back down to 98. Is it normal?

Answered by Dr. Mirjeta Guni 37 minutes later
Brief Answer:
About blood glucose:

Detailed Answer:
Hello and thank you for asking!
I have gone carefully through your concern.
First let me explain you that glucose checked with glucose meters differs with 20 mg/ dl with the venous glucose checked in laboratory.
So to diagnose Diabetes is not recommended the glucose meter but the blood checked in laboratory. the normal ranges of postprandial blood sugar is up to 140 mg/ dl. So none of the values you reported is not high.
Only one value of fasting glucose (110 mg/dl) is slightly elevated but as I mentioned before the glucose meter can give false results (up to 20 mg/dl higher or lower than the real value).
So do not get worried.
Will be a pleasure to help you further.
Kind regards,

Above answer was peer-reviewed by : Dr. Yogesh D
Follow up: Dr. Mirjeta Guni 10 hours later
This morning I tried again and it was 94. If I am a prediabetic then should it be always in the prediabetes range (100-125), not back in normal range? Also, I am a worrier with lot of stress when I saw those numbers, does this condition affect the glucose level too? Thank you.
Answered by Dr. Mirjeta Guni 13 hours later
Brief Answer:
About prediabetes diagnosis;

Detailed Answer:
Welcome back!
To make the diagnosis of Diabetes or prediabetes are needed 2 values of blood glucose over the normal ranges or a level of HbA1c over 5.7%.
So, 1 value does not make the diagnosis.
I would recommend to check blood sugar and HbA1c in lab.
In stressful situations blood sugar can be raised but in normal persons it does not get over normal ranges.
Best wishes,
Above answer was peer-reviewed by : Dr. Kampana
Follow up: Dr. Mirjeta Guni 14 minutes later
Do you think over the counter A1C is accurate? I did again postgrandial at 102 for light lunch and carby dinner at 116. So all those postgrandial tests have always been less than 140. Do you think I am ok? Thanks.
Answered by Dr. Mirjeta Guni 7 hours later
Brief Answer:
Yes, HbA1c should be checked:

Detailed Answer:
Always when there is a doubt for Diabetes or prediabetes, HbA1c should be checked for a further information regarding the mean glucose level of the last three months.
You should not get worried about these glucose levels.
There is only a fasting value, slightly over the normal ranges but it is not very reliable when checked with glucose meters.
Best wishes,

Above answer was peer-reviewed by : Dr. Vaishalee Punj
Answered by
Dr. Mirjeta Guni


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