Additional diagnostic tests?

Hi and welcome

While none of us on here can offer any kind of diagnosis, I will make a couple of suggestions and comments.

Firstly, you don’t have to be fat, inactive or obviously predisposed to develop diabetes. There are a heck of a lot of members here who lived active lives, ate ‘healthily’ and still got D. The more you read the forum, the more you will see that the current idea of ‘healthy brown carbs’ seems to set many of us up to develop type 2 diabetes.

Secondly, there is a condition called Reactive Hypoglycaemia, which is on the spectrum of glucose dysfunction (right next to Type 2 diabetes) which manifests as lower blood glucose after eating carbs. You didn’t mention experiencing hypo symptoms? So you may be asymptomatic?

We have a reactive hypoglycaemia sub section of the forum here, which you may find interesting reading, either to identify or dismiss it as a possibility.

RH is, indeed, often associated with (as a precursor to) type 2 diabetes, since it involves an overproduction of insulin which causes the blood glucose to drop to hypoglycaemic levels. Such insulin overproduction may, over time, in susceptible individuals, cause insulin resistance to develop. Several of us here on the forum find that simple dietary adjustments are enough to manage RH v well indeed.

Hypos in non diabetics may also (as you have researched) have other causes, from insulinoma to medicinal and/or recreational drugs, pre menstrual tension, and many other things. These require different treatment.

I’m very glad you have been tested thoroughly on the GTT and insulin levels. Here in the UK the insulin is not tested. Although you may find a 5 hour GTT sheds more light than a 2 hr one. It might be worthwhile knowing what happens at 2.5, 3, 3.5, 4, 4.5 and 5 hours.

Hope that helps!

LI said:

I'm currently living int he Philippines as an expat and have recently been diagnosed with hyperinsulinemic hypoglycemia based on a 75 g OGTT with samples at fasting (t=0), 1 hr and 2 hr with tests for both glucose and insulin levels. The appear to be conclusive:
Blood sugar
Fasting: 4.6 mmol/L
1hr: 4.8 mmol/L
2 hr: 3.1 mmol/L

Insulin:
Fasting: 5.74 uU/mL (ref range: 2.7-10.4)
1 hr: 18.06 uU/mL (ref range 2.7-10.4) - result was re-checked
2 hr: 11.93 (ref range 2.7 0 10.4) - result was re-checked

Hi and welcome to the forum,
The hour glucose reading is very interesting, you don't seem to have had a spike, but I would have wanted a reading every fifteen minutes, with that amount of glucose you should still be around over 7mmols. This could be glucose dumping! The insulin reading is high after an hour and two hours, which is why hyperinsulinaemia Hypoglycaemia has been thought of.
As @Brunneria has said it could be RH or some form of hypoglycaemia, but it could also be a pancreatic condition such as insulinoma.
Only further tests can give you a diagnosis.

I also did the OGTT about a year ago with only blood glucose tested -- the results were similar but the 1hr and 2 hr were actually a little lower.

The Endo interpreted the results to mean I have pre-diabetes (T2), which is, unfortunately, very, very common in the Philippines. I'm not convinced of this interpretation because I have ZERO risk factors for T2 -- I'm 5'7" at 127 lbs and have never been overweight (and don't carry weight in my abdomen -- i'm more of a pear!), I exercise regularly (run, weight train, and have always participated in sports), eat a very healthy diet (can't even remember the last time I ate white bread or pasta -- even growing up my mum was a health nut!), and have no family history. Dr. Google has suggested various (though more rare) potential causes, including insulinomas and nesidioblastosis.


My question is: are there any additional tests (bloodwork, imaging, other) I should request to be done?
I'll be repatriating in about 6 months, but before I return can take advantage of the Philippine system where you can get essentially any test as long as you pay for it (which my private insurance covers when requested by a Dr.).

Many thanks!

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The one test I would ask for, is a 72 hours fasting test.
This is a test that would eliminate one or other conditions and would give your doctors a better understanding of what is happening to you, whether the insulin response is triggered by food or by some pancreatic condition.
It would amaze me if they haven't done a full blood panel, such as c-peptide and GAD.
Did they take regular blood samples during your OGTT?

The only other tests are probably mixed meal test, and food allergies, intolerance tests.

It is good your are taking your dietary intake seriously, I avoid any food that causes the trigger for excess insulin.
Again welcome to our forum.

Do read the RH forum, even if you haven't got the condition, you will definitely see the symptoms that most RH ers and similar conditions have to cope with and how to stop the hypos.

Best wishes

Hi again, click on the expand button on my post, for some reason I have posted inside your reply post!

I think you and I are similar - I'm very thin (same height as you but only 115 lbs), no risk factors and live a healthy lifestyle too. Your fasting blood sugar and insulin are not indicative of prediabetes (I had similar numbers), but your insulin response is typical of reactive hypoglycemia. This is what confuses me too. How can we have healthy fasting numbers, which go against the standard diagnosing of insulin resistance and diabetes, yet have such a deranged insulin response? No doctor has been able to explain this to me. But know that you're not the only one, and we're all looking for answers together.

Yeah I agree! It is something that has often had me looking for answers as for why my body is completely different to everyone else bar a few!

Coolifornia said:

I think you and I are similar - I'm very thin (same height as you but only 115 lbs), no risk factors and live a healthy lifestyle too. Your fasting blood sugar and insulin are not indicative of prediabetes (I had similar numbers), but your insulin response is typical of reactive hypoglycemia. This is what confuses me too. How can we have healthy fasting numbers, which go against the standard diagnosing of insulin resistance and diabetes, yet have such a deranged insulin response? No doctor has been able to explain this to me. But know that you're not the only one, and we're all looking for answers together.

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I'm different, because, my body used the excess insulin (hyperinsulinaemia) to make me gain weight. At just before diagnosis, I was over seventeen stone approaching eighteen and getting really ill. I have a photo of me, and I look as if I'm a balloon and been overblown.
Since diagnosis, the weight initially fell off and has been stable around 80 kilos for about four years now, which coincides with my good health and avoiding carbs.
Why did I increase weight when I ate very little?
The answer was insulin resistance.
With hyperinsulinaemia, the amount of insulin in my blood was very high, and because it never got used, it turned into visceral fat around my organs and midriff.
I had non alcoholic fatty liver, liver function, kidney function and high blood sugar levels. Because I was producing so much insulin, because my brain was getting the trigger to produce more due to the high glucose readings.
It was only when I started eating low carb, that the insulin resistance and blood sugar levels came down, hence being diagnosed as T2.
Once I reached normal hba1c levels and fasting levels, my endocrinologist, was intrigued at the difference in only a few weeks as I changed my diet.
He finally understood what was going on after reading my food diary and seeing me go hypo, at a couple of appointments.
More tests and more blood giving, lots of testing and experimentation!

My theory is there is something called a gut brain trigger, when we eat, all sorts of hormones and digestive chemicals from saliva to acids and of course glucose derived from the carbs and the insulin response, to what you have ate.
With RH, when too much glucose is derived, because of a weak initial insulin response, (the initial insulin response can be asymptomatic of T2 as well!) the spike triggers an overshoot of insulin, (a secondary response) this overshoot gets rid of the high blood glucose, but the insulin is too much now and causes the hypo.
So, that is why, no hyper, no hypo!
If you don't cause a spike, no secondary insulin response!
A lot of symptoms are to do with brain function, and the list is long and unhealthy.
The roller coaster ride of blood sugars is causing the symptoms, your brain has too much glucose, then not enough, then too much, then not enough and so on.
Then there is the other hormones like oestrogen in women, testosterone in men, thyroid, adrenaline, cortisol and more, that impact on how your system copes with its metabolic conditions.
Is it understandable that unless you have come across Hypoglycaemia in whatever form or type, that our medical profession have real difficulty in a diagnosis?
Or our personal GPs, who don't have the facilities or finance to get the necessary tests? That rely on their teachers to be aware of something that is common as a symptom but not as a condition?

I'm the only patient that has this condition in my surgery of over 2000 patients!
My endocrinologist has about thirty patients that have been diagnosed and referred to him.

Yes, it is an enigma, but, as I have found, treatment is more important than why!

Best wishes

LI said:

Thanks - this is very helpful.
I only had blood drawn at t=0h (before the drink), t=1hr and t=2 hr. The only things analysed were bglucose and insulin levels at t=1 hr and t=2hr. At t=0, I also had cortisol (normal, as were at least 2 tests in previous year), and ACTH IRMA. Kidney. liver, etc. were all normal in previous tests (and in recent for unrelated testing -- they sure like blood tests around here!)

I have not had any tests for c-peptide or GAD, or the fasting test, etc. I will ask my endo for these.

Although I understand that people without the typical risk factors can develop T2, or other metabolic disorders, it seems like in my case the endo defaulted to pre-T2 because of the very high occurrence here, without ruling out (or in) other causes.

In the meantime, I've reduced my carb intake -- it was never very high and only very rarely sugar-containing goodies -- but have now completely cut out bread/potatoes/rice/starchy veg, etc. and have found it has been an improvement with balancing my energy levels (and much fewer dizzy spells). So far it doesn't seem like I have to go VLC/keto, but I'll keep track and ask for the additional tests from the endo.

Thanks again!
Lots of very helpful info on the forum!!

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Let us know how you get on.

Best wishes