MAC Wrote:"But one thing is for sure, this is a major blow to the idea that type 2 is caused by insulin resistance caused by obesity and that people with Type 2 secrete higher than normal levels of insulin which their body can't use. That belief came from studies based on HOMA calculations, but this study that measured the actual insulin secreted found that simply wasn't true."
Rosalyn Yalow received the 1977 Nobel for her discovery of a method that reliably measured the concentration of insulin and othr peptide hormones in human blood. The finding was that those who developed diabetes had significantly higher levels of circulating insulin than those of healthy individuals. This was surprising because prior to this was the belief that they didn't have enough insulin.
People
assumed based on this that the higher insulin was caused by overeating and obesity because these symptoms were associated with the condition of elevated insulin levels. However, the later research shows that high blood sugar is also merely associated with chronically elevated insulin levels.
Insulin resistance is not "caused by obesity or overeating" but by chronically elevated insulin levels. Raised insulin can manifest itself with symptoms of obesity and insulin resistance, but not always since thin people also get diabetes.
As I've maintained many times, the existing technology only allows us to get a whole body or what they're calling a homeostasis or HOMA reading that only measures whole body insulin. It does not tell us the level of insulin sensitivity in the muscles nor does it tell us what is going on in the adipose tissue. To extrapolate treatment ideas based on such little knowledge is what got us into trouble in the first place.
The insulin resistance shows up much faster than the high insulin reading yet it cannot be measured. In fact, hyperinsulinemia keeps even low-carbers from losing weight as we've been discussing all week.
Jenny Wrote:4. It makes me wonder how much of the IR that doctors believe to be the sole cause of Type 2 diabetes is actually being caused by abnormally high blood sugars. it is possible that IR increases dramatically when blood sugars go over a much lower threshold than previously believed. Possibly as low as 130 mg/dl. If so, much of the IR found in Type 2 diabetes may be caused by high blood sugars caused by insulin deficiency. If that isn't a mind blower, what is?
It may be a "major blow" but not for that reason. The reason it should be a major blow is that the HOMA does not tell us what's going on in the muscles or tissue. In other words, you can't just rely on blood sugar levels alone because the IGTT does not tell us.
The Men's Health article on
Thin Man's Diabetes told us a similar revelation:
Jeff McConnel of Men's Health Wrote:In a study published in the journal Angiology, all three tests were given to 144 patients -- none of whom had been previously diagnosed with type-2 diabetes or impaired blood sugar. Yet 94 patients yielded OGTT results that revealed one of those conditions. The fasting-glucose test had missed 62 percent of those cases, and the A1C had missed 83 percent. "The last thing to go up is your fasting glucose," says Dr. Vernon. "The horse is already out of the barn at that point." That means the first signpost doctors are looking for is the last of the indicators to present itself.
The poster child for the ADA, DeFronzo, also said in his famous Banting Lecuture that hyperinsulinemia and insulin resistance were related to "a whole host of metabolic disorders" but it required that clinical investigators measure insulin resistance in human patients which would
always be an obstacle because it requires multiple tests of blood sugar while insulin levels are held constant and precise amounts of glucose are consumed or infused into the bloodstream.
This is not the kind of test that physicians can do in a checkup and this is why insulin resistance and hyperinsulinemia
were not included among the diagnostic criteria despite being the fundamental defects in metabolic syndrome. The testing was wrong from the start.
This is why I always advise that people should eat a lower amount of carbohydrate than that which only causes them to gain weight, show glucose intolerance or any other symptom because there is so much more going on under the surface. As Dr. Vernon noted, "the cow is already out of the barn" by the time these markers show up.
One thing is for sure, insulin deficiency does not cause high blood sugar so that particular speculation should be ignored. High blood sugar does not cause insulin resistance. Chronically raised insulin levels cause insulin resistance and as Jenny speculated, fasting blood sugar levels could probably be as low as 130. Or as Jeff McConnell discoverd, his fasting level could actually show as
normal.
The problem is, the fasting test does not give us what the level is most of the time.