We hear it every day. Someone comes to us and says “I have PCOS but I am not insulin resistant”. And without hesitation, we say that we don’t believe it. Why? So far, these statements have been made by people whose doctors performed an OGTT (oral glucose tolerance test) or interpreted a fasting insulin lab value to determine that their patient was in the “normal” range. But if you’re not already pre-diabetic or diabetic, this is misleading.
The OGTT and the fasting insulin lab values are largely meaningful in the context of the whole human body, and do not measure specifically what is happening at the cellular level. They measure a combination of cellular insulin resistance and lacking pancreatic function. And in the earlier stages of PCOS, there is typically GREAT pancreatic function! This results in a “normal” OGTT or fasting insulin.
It is precisely that “champion” pancreatic production of plentiful amounts of insulin, which happens because of insulin resistance at the cellular level, that leads to extra circulating insulin. And that extra circulating insulin is the main initiator of the hormonal meltdown that leads to downline disruption of ovulation and elevated androgen levels.
Instead of relying upon an OGTT or fasting insulin as a meaningful measurement of cellular insulin resistance for non-diabetics with PCOS, we need to look at markers that exclude beta-cell function (that is another whole discussion, where PCOS has already progressed to frank diabetes). We need to separate the markers of cellular insulin resistance so we can look at this on its own.
Try this:
If your IR index by this calculation is 1.0 or greater, this generally indicates cellular insulin resistance. Are you insulin resistant based upon this measure?
Please note that this calculation may not be accurate for some people of sub-Saharan African heritage due to genetic differences in TG production. In that case, an alternative method is needed. Please check with your PCOS dietician or nutritionist to evaluate, if your doctor is not familiar with these methods.
Amisi CA. Markers of insulin resistance in Polycystic ovary syndrome women: An update – PMC: An update. World J Diabetes. 2022 Mar 15;13(3):129-149. doi: 10.4239/wjd.v13.i3.129. PMID: 35432749; PMCID: PMC8984569.
