I find it truly amazing that most doctors don’t automatically send people for a blood test for insulin resistance.
Why am I amazed?
Because insulin resistance is a precursor for the development of type 2 diabetes and it’s often present for up to 10 years before an ‘official’ diagnosis. Now that’s a long time you could do something about it if only you knew!
Insulin resistance is also known as prediabetes, they are both considered the same thing, just in case you didn’t know.
A couple of common tests your doctor might have ordered are the fasting glucose or oral glucose test, which is still important because having elevated blood glucose is also a risk factor and indicator.
But it is not uncommon to have a normal blood glucose and high insulin resistance. In fact, one of my clients recently came back with blood sugar levels in normal range but an insulin level of 16, putting her in the ‘moderate to severe insulin resistance’ range and heading on a trajectory toward type 2 diabetes!
So in my eyes testing for insulin resistance is very important. If you know your own individual status, you can work on your lifestyle habits so you don’t develop type 2 diabetes, why wouldn’t anyone want that right?!
You can ask your doctor for a test so let’s talk about what to ask for.
Blood Test for Insulin Resistance / Prediabetes
Ask your doctor for:
- A fasting blood glucose test
- And a fasting insulin test
With the results from the two tests you can calculate your insulin resistance status using Homeostasis Model Assessment (HOMA) Index.
The HOMA-IR test was developed from “the concept that fasting plasma insulin and glucose levels were determined, in part, by a hepatic-beta cell feedback loop”. Source
So essentially it calculates the balance between pancreatic beta cell function, glucose, and insulin sensitivity.
You may find that you have to pay for a fasting insulin test out of your own pocket, but it’s not overly expensive and well worth it to discover your own health status.
Fasting Insulin Test
If you use the fasting insulin test on it’s own you can still get a rough indication of your level of insulin resistance
Here are the indicator levels of you insulin resistance status:
- Between 10U/L- 14U/L indicates mild insulin resistance
- Above 14U/L indicates moderate to severe insulin resistance
- The upper limit for normal fasting insulin is 20U/L
This is the standard measurement that your doctor will likely use but this is not as accurate as the HOMA calculation because it doesn’t compensate for falling insulin and rising blood glucose, the HOMA-IR test does.
Interpreting HOMA-IR Results
So let’s take it one step further to get a more accurate calculation.
Once you have:
- Your fasting glucose numbers
- Your fasting insulin numbers
Here’s how to calculate the HOMA-IR and your level of insulin resistance.
If glucose is measured in mmol/L use this calculation (1):
Fasting insulin mIU/L x fasting glucose mmol/L divided by 22.5
The insulin resistance range:
- Normal <2.0
- Borderline 2.0-2.2
- Moderate IR 2.2-3.0
- Severe IR >3.0
If glucose is measured in mg/dL use this calculation:
Fasting insulin mIU/L x fasting glucose ug/dL divided by 405
The insulin resistance range:
- Normal <3
- Borderline 3-5
- Severe IR >5 Source
Are You At High Risk For Developing Insulin Resistance?
Here are some of the risk factors:
- BMI >25
- Age >40 years
- Waist circumference >40 inches (101 cm) (male)
- Waist circumference >35 inches (88 cm) (female)
- High blood pressure, high triglycerides, low high density lipoprotein cholesterol (HDL-C)
- Latino, African American, Native American, or Asian American heritage
- Family history of diabetes mellitus, high blood pressure, or atherosclerosis
- History of gestational diabetes
- Polycystic ovarian disease
- Acanthosis nigricans Source
If you have any of these risk factors or suspect insulin resistance, get a test!
It is better to know so you can do something about it because making some changes in that arena can help you avoid a diabetes diagnosis.
The same client I was talking about above is working with me and doing something about it! She has lost 8.8 pounds (4 kg) in 6 weeks, she is exercising, eating right and taking supplements to help. So I’m sure once we get her tested again, she is going to have lower levels of insulin resistance, and that is a VERY good thing!
Don’t leave it to chance, get the test!
You may also like to read:
Insulin and insulin resistance
Newly Diagnosed? Tips to help you out
References
Australian Doctor and The Royal College of Pathologists of Australasia. 2002. Commonsense Pathology: Insulin Resistance.
my endocrinologist got upset when i mentioned i wanted to work on overcoming IR and would not order ANOTHER FASTING INSULIN TEST. he only wants use trulicity and invokamet xr to deal with my a1c……….i fear that trulicity may work against lowering my fasting insulin but cannot find anything in the literature on the subject…my fasting insulin is 16.5 and my c peptide is 3.4 and my a1c is 5.3 with a low carb diet. he repeatedly tried to keep a brick on my head saying that i should simply follow his instructions and he put down my efforts. i am 77 yrs old 215 lbs and 6′ 1″. i have decided not to return to that dr. again. can you comment on my assumption and tell where i might be able to order labs on my own…???
Hi Brian,
I cannot speak to the your questions regarding trulicity, but I would suggest finding another endocrinologist that listens to your concerns and is willing to order the tests you are interested in.
my mother is diebatic type 2 ..her blood sugar level is too much high ..she took medicine and also insulin 20 points..but still not progress..i am so worried please tell me what can i do
Hi Hina,
I’m sorry to hear about your mother’s difficulty with diabetes. Since I don’t know anything about her medical history I would urge you to visit her endocrinologist and express your concerns.
PS. I’ve shared your notes from https://diabetesmealplans.com/diet-to-lower-blood-sugar-a1c/ with the chief diabetologist and chief endocrinologist at the major teaching hospital here in Kathmandu and I’ll be copying at least part of that to share with their staffs next week, with due attribution to your website, if that is OK with you. Thank you for the clear, concise summary of research (with references) that you provide there.
Absolutely feel free to share, Jon.
Wow, you actually answered! I’ll be at the Nepali Health Research Summit mid-week and may find some answers there as well. I very much look forward to your response when you get more time to write. Thank you! Jon
Dear Jedha,
We very much appreciate this article and the clarity it gives for testing IR using the HOMA-IR test. We’ve also seen a HOMA-Beta test for beta cell function. However this is more of a question or three than a reply.
Dr. Ede noted a formula for determining insulin resistance: the natural log of [(our fasting blood glucose x fasting triglycerides) divided by two]. Do you know if this is a reliable formula? Do you have a formula by which we could substitute HbA1C for the fasting blood glucose (fbg) ?
I think that HbA1C would be a much more reliable number here in Nepal, where diabetics typically have their fbg taken once a month. However, a serum insulin test for the HOMA-IR calculation costs a common laborer almost three days wages ($12.60), whereas a fasting triglyceride test is five times less ($2.65) (and HbA1C is $7.35).
We are planning a research project here to measure the Insulin Resistance response to Intermittent Fasting (IF) and a Low Carb (LC) diet. We see IR as a major contributor to several chronic diseases that are rapidly increasing in Nepal, including obesity and T2 diabetes. Therefore we want an affordable but accurate way to measure it. [My wife is a T2 and a former nurse who for over four years has been managing her diabetes using a LC diet and more recently (and effectively) IF and by the fbg/ftg calculations, her IR has dropped dramatically recently.] Hopefully this will provide a local evidence base for using a dietary approach to address IR in a Nepali cultural context. We may need to do some groundwork first since IF is mostly unknown here. If anyone on your staff is interested in working with us, or critiquing our efforts, we also would be very appreciative of that.
With thanks,
Jon and Diane
Hi Jon – thanks for your questions and interest in working with us on your research project. I will send you an email soon to discuss this more, but it may not be for around a week as I will be away. Talk soon.