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Any late life diagnosis of MODY 3?

S

sud5nala

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I have applied to get tested for a mutated HNF1A gene ("MODY 3"). My only dysglycemia is a weak first phase insulin response at meals. That makes me IGT. This problem surfaced while I was in my late 50s. The second phase response is fine.

It would be weird if this is my condition, since almost everybody with a bad HNF1A or bad HNF4A develops diabetes young, even if it's misdiagnosed as T1 or T2, which is what almost always happens. But I read that in rare cases, the mutations will not result in disease until late in life.
 
Yes, I've had 23andme.com in mind and I want to do it eventually.

When a person eats, the body secretes or releases insulin in two phases. The professional names for them are either "first phase and second phase" or "early phase and late phase". The first phase starts and ends within minutes of the first swallow. The second phase starts about 15 minutes in.

In my case, mealtime glucose readings, fasting insulin, and C-peptide show that my pancreas can produce plenty of insulin and that the second phase is at least OK. Unfortunately, something partially blocks the release of this insulin. A typical mealtime rise in blood glucose is between 2 and 3 mmol/l, not my 5.5!

I don't take medications for this condition. I walk long distances and I restrict the portion sizes of sugary foods. Exercise increases insulin sensitivity, which means it reduces blood glucose. Before I walked, postmeal glucose was elevated for 3 hours, now it's for 2 hours. But there has been no improvement in how high the glucose rises.
 
C-peptide. WebMD has an entry on its diagnostic value. Usually it's used as evidence that you may have Type 1. I am not quite sure of its clinical interpretation in my own case. I wonder: if fasting insulin is good, is the fasting C-peptide test redundant? One molecule of C-peptide is a byproduct of one molecule of insulin. Insulin eventually gets metabolized, while C-peptide does not. This makes the C-peptide concentration a great measure of insulin production.

Type 1 hyperglycemia is beta cell damage or loss due to autoimmune disease. The two basic causes of Type 2 are an excess in insulin resistance (IR) along with NON-autoimmune beta cell damage or loss. However, in unusual cases, there is neither insulin resistance nor beta cell failure. There is failure of insulin secretion, while the cells are still capable of producing insulin. Either a trigger to produce is missing, or a trigger to release produced molecules is missing.

My fasting glucose and fasting insulin are low, meaning normal. Precisely, they're both in the middle of acceptable. This alone, I think (I'm not medically credentialed), proves there is no excess in IR. Throw in that my blood pressure and lipids are negative for IR, and that clinches it. There's no Type 2 process.

Yet glucose goes out of control when I drink a lot of sugar. Why? That's where C-peptide came in. Do I have a sharp loss in insulin producing capacity, hidden during basal state because I might have a body whose need for insulin during basal is deceptively low? My fasting C-peptide was near the low end of the reference range. I'm not sure, but I think that being in range means that the insulin producing capacity is normal, while being low in the range means I don't have IR.
 
Galja said:
I am so glad I found you and this post. You seem very knowledgeable. Can you explain to me what the C- peptide test shows. i think I have had one of those. As for the rise, I can have quite sever rises if I have the wrong foods. And when I am ill, the rises can be more dramatic
Click to expand...

Cpeptide is an enzyme/protein (something along those lines) produced when the pancreas makes insulin - it's used to test to see if you are making any of your own insulin. I think it can also be used to see if the level of insulin production is within a normal range.
 
Dysglycemia is certainly highly variable. Our genes have a large influence on susceptibility to developing one or another type. But many genetically based diseases, including diabetes, manifest differently in different people, or may never even start. To muddy the waters further, in many genetic diseases, including diabetes, it's almost as if each patient has a unique mutation. Therefore, even if I am found to have some mutated gene, the guidance I get for the prognosis and treatment plan might be slight. To realize all this has been a frustration.

My condition is very stable -- mostly. Yours, maybe the opposite. Fasting glucose has varied only plus-minus 4% for years, and the level is good. The reasons for me to take a big interest in diabetes are that the A1c has become unstable, and my discovery that mealtime glucose is often sharply out of control. The A1c was steady at about 41 for years. (I was unaware that 41 is supposed to be a poor level. In that era, I and doctors had no concern about dysglycemia, I got omnibus testing for other reasons.) But then the A1c went up. I undertook exercise and it plunged into the normal range, for probably the first time in 10 years. I kept up the good habit yet the A1c shot up to 45. After drinking double the habitual amount of fizzy drinks for half a year, the A1c has nevertheless dropped to 41. I have believed from the beginning that the A1c is poor science, but for now it's the best indicator I have.

I get hypos. For years, I've been bedeviled with sleepiness after eating, but also after not eating. When I started researching dysglycemia a few years ago, that's when I learned that the sleepiness must be due to hypoglycemic moments. Mine are intermittent. They're so frequent, yet the pattern is so irregular, that I usually can't get a sense longterm of whether the pattern changes or not. The hypos went entirely away for a whole year, last year. I don't know whether the hypos started 10 years ago or 25. For all I know, my dysglycemia hasn't actually worsened at all in the last 2 years, it's really been the same all along.

I wish I could afford temporary continuous glucose monitoring. Until now, I have collected all the mealtime data by rare fingersticking. My skin doesn't tolerate the jabs.

There are cheap wrist cuffs for continuous blood pressure monitoring, but I have no need of them as my BP is low.
 
I'm curious to know if you got your MODY3 test result? I figured out I was MODY3 with an OGTT at age 40 and a better understanding of my family's experience with diabetes. I got the genetic confirmation more recently as well. My only symptoms were elevated BS at 2hrs and a prediabetic hbA1C. With diet and exercise I'm managing things well without meds for now.
 
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