insulin resistance vs. prediabetes

tfkeel

"insulin resistance" is one possible cause of diabetes, the other being that the pancreas is not secreting enough insulin. "Insulin resistance" increases with weight, simply because there are more cells which must share the insulin produced by the pancreas, however, weight is not the only factor, there are predisposition by heredity, age, and exercise level.

"prediabetes" describes a condition in which the individual is seen to be on a progression toward diabetes, but does not yet exhibit sufficient inability to process glucose to require medical intervention.

jdl958

So, you're saying that they are different, right?

tfkeel

Yes. I am saying that "insulin resistance" is a contributor to diabetes - insulin resistance alone may not be sufficient to cause a person to have diabetes in the absence of other factors.

This is a speculation - not a cite of a known case -

Let's say there is a person who is of below normal weight, having a low BMI, which means he has lots of muscle and very little fat. He has insulin resistance, but no family history of diabetes for 3 generations. He exercises vigorously 4 days a week. His HbA1c measures 7.1. He has a tendency to eat starchy foods and not too much lean meat or green, leafy vegetables.

This person could conceivably get labeled "prediabetic". His HbA1c is not sufficiently high to cause his doctor to prescribe medication. In reality, this
person is probably non-diabetic, even though he is insulin resistant, because the other factors are not present. His HbA1c might go down to 6.5 or lower if he would simply change his diet to include less starches and more veggies.
His doctor sends him home with encouragement to eat better.

Now, let's let our fictional person stop exercising, gain 45 pounds, and not change his diet.

His HbA1c is now 8.6 - his doctor diagnoses him with diabetes, prescribes Amaryl, and tells him to come back in 3 months. His insulin resistance is now
sufficient to cause him problems.

Now, I am going to describe a person I know well. She is a close relative, so I know all these things. I have watched this for years in absolute unbelief.... If I had a lifestyle like this, I would be dead.

She has a family history of diabetes, her mother was insulin-dependent before she died. She weighs nearly 300 pounds on a 5' 6" frame, she is largely confined to bed with fibromyalgia and migraine, as sedentary as sedentary can get. Her diet is awful, it is comprised largely of junk food.

Her fasting blood sugar is low 90s. She doesn't even make "prediabetes" -
this is a clear case of having no insulin resistance, she can ingest huge quantities of carbs with no lasting rise in blood sugar. Even though every other factor is present, she is nondiabetic because she is not insulin-resistant. Her doctor doesn't even bother to send her for HbA1c test - he knows it will be 5...

Fictional person #2 has normal weight, good exercise, no family history. However, she has a congenital pancreatic deficiency which causes her to manufacture insufficient insulin. She has diabetes, and is insulin-dependent. Her low dose, compared to others of similar size and age, shows clearly that she is not insulin-resistant, it is simply that she doesn't have enough insulin to keep her sugar levels down.

jdl958

Thanks, I think I get it. When I have had blood work done for high blood pressure in the past month (twice), the doctor keeps targeting in on my blood sugar level, wanting to do a fasting test. But I won't do it. I think the level is completely normal for someone who just ate breakfast, and I don't want to be tested because I know I'm not diabetic. I'm already trying to lose weight and exercise. The thought of getting labeled with something I don't have makes me crazy. Just wanted to get my terminology straight. Thanks again.

SamQKitty

I'm sorry, TFK, but your information is only accurate up to a point.

First of all, the medical community uses the terms "insulin-resistance", "impaired glucose tolerance" and "pre-diabetic" pretty much interchangeably. They ALL refer strictly to Type 2 diabetes.

Second, it is absolutely critical that a person be diagnosed as soon as possible and take immediate steps to manage this condition. If not done, then the disease will progress rapidly, rather than slowly. Of course your info on diet and exercise is absolutely correct.

Third, Type 2 is a progressive illness, and the progression varies greatly from individual to individual. Unfortunately, there is no way to measure exactly how advanced it is at diagnosis or how quickly it will progress. In some people (even relatively thin people), diet and exercise alone are not enough to manage it and oral medications must be introduced. This is very important to understand because IF you need medications, it is far better to get on them sooner in order to prevent complications, rather than waiting for months and/or years and end up with the beginnings of serious complications.

JDL, I suspect your doctor wants to do a fasting blood glucose because they can get a better idea of what's going on. For example, if your post-meal blood sugars are only slightly elevated, but your fasting are not at all elevated, then you probably can manage for quite a while (years even) on just diet and exercise. On the other hand, if your fasting levels are elevated, this means that your body cannot even handle its basic metabolic function and, depending on how high the fasting is, you might need medication. Of course it's often still possible to manage with diet and exercise alone even if your fasting bg's are elevated, but it depends on how high, how much, if any, weight you can lose, whether or not you can stick to a low-carb diet and an exercise program.

Also, since this IS a progressive illness, it's important to be regularly monitored, again so other measures, if necessary, can be introduced BEFORE damage is done. The unfortunate part with diabetes is that damage can be done that you don't even feel or know is happening, and by the time you have any symptoms, it's too late to reverse the damage. You made the following statement, "I don't want to be tested because I know I'm not diabetic"...wouldn't you rather KNOW so you can avoid kidney failure, eye damage, heart damage, vascular and nerve damage? If the test shows you are, so be it. If the test shows that your not...even better! Frankly, I would not want to be going to ANY primary care physician who did not routinely run fasting blood glucose levels on all his or her patients. It's cheap, it's easy, and when it comes to diabetes, prevention and/or early diagnosis can make the difference between living a normal lifespan in relatively good health or being beset by all kinds of major complications.

Ruth