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Avatar universal

Glucose Tolerance Test


I am not sure if I can post this here but since I am being tested for diabetes and reactive hypoglycemia.

I have been seeing an endocrinologist because I am constantly having low blood sugar readings and have had a high fasting blood glucose test of 8.3. My endocrinologist feels this may be due to my dysautonomia. She thought maybe reactive hypoglycemia because I am having low fasting glucose levels as well as high.

I went for a 2hr OGTT today and I am feeling horrible after the test.

My baseline was 4.8 @ 8:55
Given 75g of glucose to drink
At 4.3 @ 9:25
At 4.8 @ 9:55
At 6.2 @ 10:25
At 6.3 @ 10:55

After the test I went to eat something and started feeling very shaky and out of it at about 11:30. I took my blood sugar and it was 3.0. So I took 15g of dex (glucose) tabs.I tested again and I was 5.3 And ate my lunch. Again, 30 min after my blood sugar dropped from 4.1. Its been dropping within a half hour now all day and I am constantly trying to keep it up despite drinking/eating and snacking.

Is this a normal OGTT?? Is it normal having problems after a OGTT keeping sugars up? Thank you!!!
Best Answer
141598 tn?1355671763
"Would it be correct for me to say that my one hour reading should have been the higher reading of 6.3? And then at the two hour mark my sugars should have started dropping back to my starting numbers?"
This would be a good assumption. After fasting normal glucose levels are 60/70 to 99 mg/dl. With an OGTT, at 1 hour normal levels are <111.1 mmol/l [<200 mg/dl], 2 hours <7.77 mmol/l [<140 mg/dl]. For reactive hypoglycemia, the OGTT does not really apply as other factors come into play. Mostly used to help determine hyperglycemia.

"However,I was under the impression that adrenaline caused glucose to be released from the kidneys and in turn it would cause blood sugar to rise????"
Adrenaline raises glucose levels by stimulating the liver to change glycogen into glucose. When normal glucose regulation fails with type 2 diabetics, the kidneys are forced to remove excess glucose via the urinary tract. This usually is caused by insulin deficiency. In your case this does not apply.

I have read that one of the common symptoms of POTS is reactive hypoglycemia, lowering of glucose. Researchers have come to understand that this lowering of glucose levels is not the only cause, because patients’ bodies are also producing excessive amounts of adrenaline and other stress hormones.This site, The Serotonin Connection, better explains the connection between overproduction of adrenalin and stress and hypoglycemia.

Lastly, search on how the pancreas produces insulin. Specifically the Islet and Beta cells.
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141598 tn?1355671763
Well, these last test results are much much better then your first. HOORAY!
Fasting is normal 3.8 mmol = 69 mg/dl
1 hr is normal 4.7 mmol/ = 87 mg/dl
2 hr is normal 4.3 mmol/l = 77 mg/dl

For future references here are mmol/l glucose ranges -
Fasting normal: 3.4/3.9 to 5.5 mmol/l
Prediabetes: 5.6 to 6.99 mmol/l
Diabetes: >7 mmo/l
Normal postprandial = normal fasting levels

Helpful - 0
Avatar universal
Soooo... I had to have my OGTT done over,,, My endo forgot to tell me that I was to fast before this test. So the morning of my first test I took my pills with orange juice...my doctor had me go back and take the test again.

My fasting levels were 3.8
Had 75g of glucose
1 hr I was 4.7
2hrs I was 4.3

Is this more normal?
Helpful - 0
141598 tn?1355671763
You're right, β-blockers do blunt some hypoglycemic symptoms. As far as "do they have any effect on the beta cells", for t2 diabetics and non-diabetics β-blockers are known to inhibit insulin production and cause insulin resistance.
Helpful - 0
Avatar universal
Does a beta blocker have any effect on any of this? I am reading on how the pancreas produces insulin and that beta cells make and secrete insulin. I take 25 mg of atenolol 2x daily. I do know they can block the symptoms of hypoglycemia...But do they have any effect on the beta cells. Sorry for my numerous questions :)
Helpful - 0
141598 tn?1355671763
You're welcome. Glad to be of help. I understand about doctors explaining things, confusing and jibberish at times. Get your hands on a digital voice recorder and record what he/she has to say - it will become a good friend to you. At home you can review what was spoken as many times as needed. This also gives you an opportunity to look up medical words/terms which they unknowingly use.
Helpful - 0
Avatar universal
Thank you very much for you help! I find this stuff so confusing and when my doctors try and explain to me what is going on I never understand what they are talking about :) Your help and information is very much appreciated!!!
Helpful - 0
Avatar universal
Would it be correct for me to say that my one hour reading should have been the higher reading of 6.3? And then at the two hour mark my sugars should have started dropping back to my starting numbers?

I have not had any additional tests as of yet this is my first test ordered by my endocrinologist

In regards to the dysautonomia I believe my endocrinologist is thinking because I have higher levels of adrenaline and that it is causing my body to constantly be lowering my blood sugar. I have Hyperadrenergic POTS (postural orthostatic tachycardia syndrome) I have a overeractive sympathetic response to standing, the autonomic testing I have had done showed I have very little parasympathetic response and am always dumping/have a spillover of adrenaline.. And that its the excessive amounts of adrenaline/stress hormones that may be causing this?

However,I was under the impression that adrenaline caused glucose to be released from the kidneys and in turn it would cause blood sugar to rise???? But I also suppose that adrenaline is not the only stress hormone and each would affect sugars differently. I really do not know much about diabetes so I again may be wrong! :)

Helpful - 0
141598 tn?1355671763
Yours is a very interesting and puzzling post.
"Is this a normal OGTT?? "
No. At 10:55 your levels should be between 3.9 and 5.7 mmol/l, close to where you started, 4.8 mmol/l.

"Is it normal having problems after a OGTT keeping sugars up?"
No. In the diabetes world you are experiencing what they call hypoglycaemic episodes [hypoglycemia] - low blood sugars after eating [postprandial]. I can only assume your endo has tested your pancreas, your pituitary, thyroid and adrenal glands, and liver functions for abnormalities.

One of the most important thing to do is to change your diet/nutrition opposite of an type 2 diabetic. It should consist of a lot of carbohydrates - potatoes, white breads, white rice, pasta, etc - and be divided into more, but smaller meals - breakfast, lunch, dinner and three in-between meals - to avoid the big fluctuations in the insulin secretion from the pancreas. Carbs when digested quickly enter the bloodstream as sugar.

According to Wiki, the term "dysautonomia (autonomic dysfunction) is a broad term that describes any disease or malfunction of the autonomic nervous system." I suppose in order are consultations with a Neurologist with specialty in autonomic disorders, and a Cardiologist with specialty in electrophysiology. Sorry, but this way above my area of knowledge and limits my response in this area. Might consider posting on the Ask A Doctor - Autoimmune Disorders and Neurology - forums. Good luck
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