by Dr. Spencer Nadolsky
If you have read a lot of our articles, we focus a lot on what is called - insulin resistance. If you want a quick review of what it is you can check out my video – How Diabetes and Berberine Work – Part 1. The quick definition is just, a condition where cells fail to respond to normal levels of insulin. Increased insulin resistance means your pancreas needs to make more insulin to get glucose into your cells.
It is important to know your level of insulin resistance (or insulin sensitivity) because it is something that predicts cardiovascular disease and diabetes risk. It is also something that is EASILY modifiable with lifestyle and supplements AND also easily measured, which is why even fitness pros could use this as another variable to a client’s success.
How to test insulin resistance
The Gold Standard of insulin sensitivity/resistance testing is with something called a Hyperinsulinemia Euglycemic Clamp. It is an invasive procedure where insulin and glucose are infused into your veins and someone measures how much insulin is needed to keep your glucose levels in a certain range for an extended period of time. While definitely interesting, I wouldn’t recommend this… and other than a research lab I wouldn’t know how to even try to attempt this technique.
No need for long lab drawing… just a short one!
Luckily there is a calculation based off of your fasting glucose and insulin levels that predicts your insulin resistance very closely to the clamp method above. It is called the HOMA-IR – Short for Homeostatic Model Assessment – Insulin Resistance. The model was based off of young lean individuals using the clamp method so it isn’t 100% accurate for the entire population but it definitely has a good correlation and can be calculated quite easily.
Here is how to calculate it using either the US Formula (how we do it in aMERICA!) or International Formula
US Formula
fasting Glucose(mg/dl) x fasting Insulin(µU/mL) / 405
International Formula
fasting Glucose(mmol/L) x fasting Insulin(mU/L) / 22.5
For example, my fasting Glucose was 90 mg/dL and my fasting insulin was 5 µU/mL so (90 x 5)/405 = 1.11
There have been many proposed cutoff values depending on your age and race, but in general you can use this guideline:
| Category | HOMA Score |
| Normal insulin resistance | < 3 |
| Moderate insulin resistance | Between 3 and 5 |
| Severe insulin resistance | >5 |
In a discussion with some other weight loss docs we talked about just using fasting insulin as a good marker. If you’re doing this you can generally use 10 or 11 µU/mL. Anything over those values likely means you’re insulin resistant. However, since a fasting glucose is pretty easy to get, you might as well calculate your HOMA-IR.
You can get a pretty cheap one at Walmart!
Some of you nerds out there may be wondering about the update to the HOMA, which is the HOMA2. This update makes up for differences in peripheral vs. liver (hepatic) insulin sensitivity (see my video – How Diabetes and Berberine Work – Part 2). That equation is supposed to be even more accurate but it isn’t as simple as the above. You need to know your c-peptide too and you need to download the calculator (won’t work on newer macs for the time being, but Oxford is working on that).
So now the trouble is how you are going to measure your fasting insulin (fasting glucose can always be done with a glucometer from Walmart). You have a couple options here:
1. Convince your doctor to order the test (it is always tough to get us docs to do anything you want isn’t it? – hah)
2. Order it yourself from a place like www.directlabs.com or get a complete panel from www.wellnessfx.com
Once you get it you can do the calculation yourself pretty easily. If you’re insulin resistant, get a good exercise and diet plan along with something like berberine so you can defeat it!
If you think this is interesting and would like to learn more, make sure you sign up for our newsletter below. I am thinking of putting together a nice resource for those who think doctors don’t explain lab values enough. It will definitely help those who want to empower themselves and be proactive with their health as well as for fitness pros who have clients that can’t get help from their docs.
References
1. Diabetes Care. 2007 Feb;30(2):318-24. http://www.ncbi.nlm.nih.gov/pubmed/17259501
2. http://www.who.int/chp/steps/2007_STEPS_Survey_Paper11.pdf
3. http://jcem.endojournals.org/content/90/10/5698.full
4. http://www.ncbi.nlm.nih.gov/pubmed/3899825
5. http://www.dtu.ox.ac.uk/homacalculator/index.php
