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Recent OGTT result

Bi @Grazer, With all due respect I would suggest not making your own diagnoses. The OGTT is standardised so that the results can be compared to a set of ranges specified for it. You can guess the interpretation but not state it as a certainty.
Nor is it wise to make assumptions about results of the other persons who performed your test, without use of a standard test and the knowledge and training to interpret it. Nor recommend a non-standard test to someone else.
 
They are NOT assumptions I am making. The figures I am quoting AND the methods are exactly those used clinically. Nowadays as a time and cost saving OGTT tests are seldom done and when they are, clinicians don't sit there for 2 hours taking multiple tests. But they should, and they used to. The tests I conducted were not non standard but exact clinical standards which used to be 70 grms of anhydrated glucose but now clinics use 440 mls standard flavour lucozade, same glucose content. With respect, as you say, please don't lecture me. Most of the advice/comments made on this forum are based on individuals own experiences and interpretations. I would provide detailed links to clarify the figures I quote and suggest, but I'm currently out of the country and cant
 
I've done two OGTT under hospital conditions. The glucose drink is based on your weight. I was 56 kg and got 60ml of a sickly sweet yoghurt type drink.

I'm T1 and did one test within a few months of diagnosis and the second a year later. My glucose levels peaked (15) & started dropping again in test 1 - i was still producing some insulin just 'sluggish'.

A year later and I was feeling very ill after 2 hours. BG at 19
 

For type two or prediabetes, an OGTT is standard at 75g of pure glucose, the fasting or none fasting glucose tolerance test is dependent on what they are looking for.

The tests are not as thorough as they once were. Indeed, I have heard that only pre glucose drink and two hour readings are only taken in some such tests, not the usual, reading every fifteen or thirty minutes readings. And no c-peptide or GAD test either.

A true diagnosis for an extended OGTT, requires fasting reading, readings every fifteen minutes, for first hour, then half hourly, till up to five hours after, unless the readings go too low. As well as a venous blood sample taken, pre glucose, an hour and when the test is finished.
The reason for the extended test is to discover what happens after the two hours.
Because some blood glucose levels do not drop into the patients hba1c levels until after the two hour mark.
A c-peptide and GAD are necessary as a diagnostic tool to measure insulin levels.

Some type two have symptoms and hypoglycaemic episodes similar to Reactive Hypoglycaemia!
Some metabolic syndrome conditions, within the diabetes or endocrine need longer than the standard two hour glucose tolerance test!
 
Thank you @Grazer, @Circuspony, @Bluetit1802, @Lamont D, - it would appear the set standards have changed somewhat over time. From my reading:
I assume hospital tests will be done by sampling venous blood, not capillary blood. I am guessing BSL results will be different depending on type of blood sampled, method of measurement and error ranges of each method and thus will not be directly comparable.?
And is CGM too inaccurate to use or to calibrate and standardise in place of multiple venous blood samples if new standards could be set???
And if BSL tests are not performed before the 2 hour mark will things like dumping syndrome may be missed?
And for extended OGTT lack of multiple sampling might lead to the actual low BSL being missed as @Lamont fears.?
And what is the utility of extending the test time for someone whose standard test is interpreted as T2D ? Does the doctor assume that the only utility is to detect a possible low BSL at say, 3 to 4 hours after test start ? Although could such knowledge be useful to the patient to help explain why they feel they have to eat at that time, and which makes their condition potentially worse.?
Does it also inform HCP and patient about dietary choices.?
 

I'm going to be brave enough to try and answer your very interesting questions!
Here goes!

1. Venous blood in my experience is the norm for tests, although a glucometer is used for the intermittent readings. Yes!
2. I would believe the initial insulin response and high spike will be a clue to either gastric dumping or a possible metabolic syndrome type condition.
3. You've answered the question yourself. Any diagnosis depends on data, the more the better!
4. The extension of such tests, has to be one of eliminating other conditions.
Most tests that are designed to eliminate other metabolic conditions. Such as with an eOGTT, if you have an hypoglycaemic episode during this test, that you may have a type of hypoglycaemia. The norm for a type two is not to have a hypoglycaemic episode. During a fasting test, if you have a hypoglycaemic episode during this test, it will not be Hypoglycaemia, it would be a pancreatic condition, as with insulinoma.
5. Any dietary knowledge which will help control of blood glucose levels and hba1c levels has to be individual. There are many reasons, and why a food diary and regular testing is beneficial, it gives an overview of what happens when and what you eat. And more importantly what to avoid, those with insulin resistance and low initial insulin response, will discover what foods that they are intolerant to.

Not bad for a layman!

Best wishes
 
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