Oral glucose tolerance test results - seeking members' opinion

[Praveen55]

Hi Friends,

Recently I got my blood work done and in this post, I would like to share and seek your opinion in particular on OGTT test results.

Test preparation: I had been on very low carb diet ( 25gm + - 5gm a day), therefore I had to increase the carb intake to 120gms/day for four days preceding the test as per Doctor's advice.

Test set-up: Medical centre, please note that they take only two tests one fasting one and another 2 hr OGTT. Using my meter I took two further readings at 60 and 90 minutes interval. Following are the results:

1. Fasting Blood Glucose: 104 mg/dl 10 hrs overnight fasting ---Lab result

Consumed flavoured drink having 75 gm of pure glucose in two minutes

2. 1 hr after the drink: 225 mg/dl Self-monitored

3. 1.5 hr after the drink: 167 mg/dl self monitored

4. 2 hrs after the drink; 70 mg/dl Lab result

First I thought the lab results may be wrong but I was told it was highly unlikely. Then looking back when I was on conventional high carb diet( 60 % or so), I used to feel hungry every two hours or so after eating enough food The very low blood glucose at the end of two hours makes sense perhaps. Please give your opinion.

[rvmasalvad Volunteer Star]

Are the readings with or without medicine?why did you increase carbohydrate diet?

[Praveen55 Moderator in reply to rvmasalvad]

No medicine. Why did I increase Carbohydrate - that is the requirements of OGTT.

[ramana42 Volunteer in reply to Praveen55]

Celebrate.What are you waiting for?Anyway,better repeat the test to be on safer side.

[Praveen55 Moderator in reply to ramana42]

what about 60 mts and 90 mts readings? Are they not too high?

[ramana42 Volunteer in reply to Praveen55]

It does take some time to metabolize all that glucose. I think those two numbers are bound to be higher, but your system has overcome the heavy glucose load.

[Praveen55 Moderator in reply to ramana42]

It has overcorrected.

[ramana42 Volunteer in reply to Praveen55]

How is overcorrection possible in the absence of medicine? Hitting 70 looks inexplicable to me,to say the least.

[cure Administrator in reply to ramana42]

ramana42 very recently...I checked my 2 hrs ppbs which was 124...after that I consumed half laddu from Tirupati balaji mandir...

and then after 2 hrs my ppbs was 97

[ramana42 Volunteer in reply to cure]

Balaji ka kamal hai,Bhai!.Time for me also to plan for darshan.

[suramo Star in reply to ramana42]

Praveen55

ramana42

The four readings are uncomparable. 2 are from a lab and the rest are taken using the glucometer. Lab reports tend to be lower. Actually, the lab should have taken more readings with insulin levels. That would show if IR is developing.

Since 1 & 1.5 hr readings are high, then you should take repeat gtt with insulin assays. The blood sugar should never go above 140 mg. Tc.

[Praveen55 Moderator in reply to suramo]

Hi Suramo,

These are the best I could arrange. I know it would be better if all monitoring is done by the lab and Insulin also included. Unfortunately, I am not in a position to decide what and how it should be done. It is up to my Doctor. Hence I used my Glucometer. You are right- GM readings are generally higher than the lab but less than 5% higher. I have checked this in the past.

My BS always exceeds 200 if I take a carb-rich traditional meal. I was, therefore, expecting above 140 reading out of OGTT but not 70 after two hrs. But other members have indicated it is not unusual among diabetics/pre-diabetics.

I understand that I have to continue keeping carb intake as low as practical.

[ramana42 Volunteer in reply to Praveen55]

What needs to be explained is,how one can hit 70 without being on medication.Not having any clinical knowledge,but it looks to me that insulin assaying alone will nail the issue.

[suramo Star in reply to Praveen55]

Praveen55

Find a doctor who will listen to your suggestions. The lab has nothing to lose. You will have to bear little more expense.

[ramana42 Volunteer]

On the face of it,it looks like you are not a diabetic.You almost hit the hypo level and it must have been due to medicines you might have taken.You can get a correct inference only when the test is done without medicines.To me,it looks like you are a free man.

[Praveen55 Moderator in reply to ramana42]

As I said I take no medicine. This kind of blood glucose behaviour is called Reactive Hypo which is due to insulin resistance in the beginning and then too much release of insulin during the later part causing hypo or very low BG.

[Hidden in reply to Praveen55]

I take 250 mg metformin every night after dinner. At my recent blood test my FBS was 126 and PPBS 98, both done at a hospital, based on the meds I had taken the previous night - no meds taken between FBS and PPBS. The doctor asked me not to worry - the FBS was high because of the liver releasing glucose!

[Hidden]

Praveen55

Type 2 diabetics face 2 issues. They are:

Insulin resistance and loss of 1st phase insulin release.

Eating a low carb diet has made you insulin sensitive, but lost 1st phase release cannot be recovered.

Also, chronic excess carb consumption is one of the causes of diabetes.

So, we can't go back to old habits.

Continue the low carb dieting.

[cure Administrator in reply to Hidden]

congratulations Praveen55 you are doing really great...I have experienced this reactive hypoglycemia many times...

Even Hidden explained same after his food at some traditional south Indian wedding...

And as he said rightly...1st phase insulin response is gone.... and so we diabetic although show good numbers at end of 2 hrs... still sugar goes high at 30/60 and 90 mts...

[Praveen55 Moderator in reply to cure]

You are right, cure. Good thing is that It is fixable by low carb diet.

[gangadharan_nair]

Diabetes is diagnosed with the following blood tests:--

Fasting blood glucose level -- diabetes is diagnosed if it is higher than 126 mg/dL two times

Random (nonfasting) blood glucose level -- you may have diabetes if it is higher than 200 mg/dL, and you have symptoms such as increased thirst,

urination, and fatigue (this must be confirmed with a fasting test)

Oral glucose tolerance test -- diabetes is diagnosed if the glucose level is higher than 200 mg/dL after 2 hours

Hemoglobin A1c test

Normal: Less than 5.7%

Pre-diabetes: Between 5.7% and 6.4%

Diabetes: 6.5% or higher

According to the above criteria, you are not a diabetic patient. PPBS: After 1 hour result is slightly higher (Normal- 180 mg/dL to 200 mg/dL). The same may be ignored.

Sources:--

en.wikipedia.org/wiki/Gluco...

medlineplus.gov/ency/articl...

[cure Administrator in reply to gangadharan_nair]

hmmm...but what if one hr it goes beyond 180...which is threshold for kidney...

Praveen55 have they done urine sugar also at same time???

If it is going beyond 180 any time then trace of sugar will be seen in urine... and when kidney is throwing sugar...and condition remains for longer time...kidney will be affected.

[Praveen55 Moderator]

In my case, it will not go above 140 under normal circumstances as long as I am on low carb diets. With normal high carb diet, I always hit 200 mark. I have checked this several times.

One thing is surprising though, you say 180 is the threshold for kidney problem but according to my Doctor up to 200 ( 11.1 mmol/l) as random reading is normal. And this is not his opinion, he follows the book. In fact, this is a common practice in the UK health service.

Please see the second table in the link below:

diabetes.co.uk/diabetes_car...

PS: Functional/Reactive Hypoglycemia: Maybe this is the way, Dr Vishwaswaoop Biswas demonstrates fall in blood sugar in diabetics after 500gm sugary fruits consumption.

Just a wild guess.

[cure Administrator in reply to Praveen55]

kidney.org/content/sugar-an...

Sugar is not a problem for the kidneys unless the blood sugar level gets too high. This commonly occurs in both Type 1 and Type 2 diabetes. Once the blood sugar level gets higher than 180 mg/dl, the kidneys start to spill sugar into the urine. The higher the blood sugar, the more sugar comes out in the urine. If your kidneys are normal, this usually isn’t a problem, but if you have diabetes, too much sugar can cause kidney damage.