By Dr Joe
Here is a little secret. Insulin resistance is a silent killer. There’s a saying in life that goes: “ignorance is bliss”.
That may be true, but with insulin resistance, ignorance is at your metabolic expense.
On this page, I’m going to reveal the origin of insulin resistance, what insulin resistance means, the health implications, how you can tell if you’ve got insulin resistance, the link to metabolic syndrome, the test for insulin resistance. The whole shebang…
Oh, and what has insulin resistance got to do with the ‘Shouting Boss‘ in the office and even Nymphomania (don’t worry, I kept it clean, really clean)? Interesting, right?
Why do we need to do know about this anyway?
Because insulin resistance has some serious health implications. Understanding the concept of insulin resistance is important to our metabolic health. But before then, how common is insulin resistance?
The prevalence of diabetes is about 285 million the world over at present, and figures expected to reach nearly 440 million in another 15 years.
Insulin resistance nearly always precedes type 2 diabetes. In fact, it is the first stage of the development of type 2 diabetes. It is estimated that 24% of adult population in the US over the age of 20 have insulin resistance.
Which means that 24% is a chunk of the population waiting for type 2 diabetes to strike.
What is insulin resistance?
Insulin resistance is basically a situation where the peripheral cells mainly the liver cells and muscle cells stop responding to simple commands by insulin to take up glucose from the blood circulation.
What this resistance to insulin also means is that; your body will need more and more and more (not a typo!) insulin to remove a unit gram of glucose from the blood circulation progressively with time because of the unresponsiveness of the cells.
The net effect is that blood sugars will remain high despite circulating high levels of insulin.
The Need for More…
Have you watched the movie, Nymphomaniac?
That movie, Nymphomaniac represents Film Director, Lars Von Trier’s final instalment of his Trilogy of Depression. The first 2 movies being Melancholia and Antichrist.
In the movie, Joe beautifully played by Charlotte Gainsbourg is in search of elusive happiness in her life. Joe decides to get loose and becomes a sucker for punishment as a result. Joe is depressed and hates herself. This makes her embark on a journey of pleasure seeking to escape her depression.
Joe wants more pleasure, more intensity to the pleasure and then some more. Sadly, all of these pleasure never gets her the happiness she seeks and deserves frankly. Instead her pleasure-seeking journey sinks her further into a spiral of more depression.
In explaining her journey, Joe utters the line:
“Perhaps the only difference between me and other people is that I’ve always demanded more from the sunset. More spectacular colors when the sun hit the horizon. That’s perhaps my only sin.”
Joe’s constant need for pleasure is what happens in insulin resistance. There’s a constant need for more insulin.
This is because the cell receptors that open the doors to allow glucose into the liver and muscle cells out of the circulation have become unresponsive i.e resistant.
Just like Joe kept seeking more pleasure or like our dear old Oliver Twist who kept asking for more…
But how does insulin resistance come about?
Yep, let’s talk about how insulin resistance develops next…
Another analogy is in order here – The Shouting Boss.
Imagine working in an office where your boss is the shouting type. Instead of giving gentle instructions, he shouts. Heaven help you if you are unable to complete a task on time. His red mist will descend on you.
In an attempt to make him change his ways, you spoke to the wife at the christmas party (families were invited to the party). You gently requested the wife to have a quiet word with him at home; that you were uncomfortable with his temperament and attitude in the office.
And you would appreciate it, as indeed everyone else in the office, if he could modify his behaviour.
His wife responds: “He’s like that at home. I’ve tried and failed, so we let him be. Ignore him. He barks, he doesn’t bite”
The salary is really good though, so the prospect of changing jobs is not that appealing.
What do you do?
You make a decision to ignore his shouting as his wife suggested. What have you done? You have chosen to become resistant to his noisy antics.
That’s exactly what happens in insulin resistance. You eat lots of refined carbs and sugary foods. These foods trigger a huge amount of insulin to lower blood sugar. Initially small amount of insulin was needed to lower blood glucose when you were insulin sensitive (the opposite of insulin resistance).
But as the years roll by and with constant demand for more insulin to deal with refined carbs and sugary foods, the liver and muscle cells became resistant to the insulin. Like the shouting boss, the cells stop listening to insulin commands because insulin keeps shouting at them.
In an attempt to stamp his authority, your boss shouts louder and louder in order to be heard. In the case of insulin, the beta cells that make, store and release insulin also “shout louder” by releasing more and more insulin, because the liver and muscle cells are unresponsive.
Hence, very high insulin levels in the blood circulation. This is called hyperinsulinemia. Hyperinsulinemia is a hallmark of insulin resistance.
So, you end up with high blood sugars despite high insulin levels.
How insulin works: Let’s get a tad geeky
Normally, when you eat let’s say a carbohydrate meal, the starch and sugars which constitute the carbs get broken down to glucose which is the form of carbohydrate absorbed into the blood stream.
Glucose absorption triggers the release of insulin into the blood stream from the organ called the pancreas.
The critical trigger point for the beta cells of the pancreas to release insulin is when blood sugar rises above 5.5mmol/l (100mg/dl). Insulin’s job is to facilitate the use of the glucose by the body cells in particular, the liver cells, the muscle cells and fat cells.
The main functions of Insulin include:
- Uptake of glucose form the blood circulation by the muscle, liver and fat cells. This process helps to bring blood sugar levels down to normal.
- The cessation of further glucose production in the liver.
- Storage of glucose in the form of glycogen in the liver and muscle cells.
All 3 actions of insulin result in lowering blood glucose levels.
The release of insulin when we eat is in 2 phases. If the 1st phase insulin release does not sufficiently lower blood glucose, then it is expected that the 2nd wave insulin release should peg blood glucose back down to the pre-meal levels.
But in insulin resistance, even the 2nd wave struggles to reduce blood sugar levels. This prompts the release of more and more insulin. This is more or less a prolonged 2nd wave insulin response.
The liver and muscle cells usually mop up three-quarters of the glucose from the blood circulation. The trigger event that causes these cells to become unresponsive, thereby blocking glucose entry into the cell is hotly debated scientifically at the moment.
Why do these cells “lock their doors”?
Do these cells lock their doors to glucose because of inflammation, oxidative stress or free radicals?
The answer is not very clear. Treatments targetting these possible explanations have proved ineffective.
If inflammation, oxidative stress and oxygen free radicals aren’t the reason for the liver and muscle cells shutting their doors to glucose, then some other explanation has to be sought.
The “starved cell” theory where the liver and muscle cells appear to be starving in the midst of plenty seems to be going out the window.
The cell was thought to be glucose-empty even though there was high blood glucose in circulation and all around it. The cell can’t seem to access the glucose regardless.
If we can’t find any explanation as to why the “hungry cell” can’t soak up the sugar all around it, then maybe the cell is not actually empty or “hungry” after all in insulin resistance.
An alternative explanation is needed guided by what happens in real life in clinical practice.
The New Thinking seems to be that:
- Insulin itself causes the insulin resistance – remember the shouting boss analogy?
- The liver and muscle cells are actually full-up with sugar.
Yes, the liver cells and muscle cells are bursting at their seams with glucose, that there isn’t enough room to let more sugar in.
That is probably why treating patients with Type 2 diabetes with insulin (when insulin resistance progresses to type 2 diabetes) does not necessarily work in the long term.
These diabetic patients will be needing more and more insulin shots to force the sugar inside the cells.
Higher and higher insulin doses needed because the cells are resistant to the insulin shots.
The resistance persists because the root cause of the problem has not been taken care of.
You may succeed but only temporarily.
The solution is to empty the cells of the sugar load inside them.
That’s why exercise is a good remedy for insulin resistance and type 2 diabetes – Exercise empties the cells and allows new sugar in.
Also why eliminating refined carbs and sugary products work for insulin resistance – Doing so reduces incoming load of new glucose.
That’s why intermittent fasting also works for insulin resistance – Intermittent fasting empties the cells creating room for new glucose to get inside.
Also why calorie-restriction diet like the type Roy Taylor professes work for insulin resistance – reduces incoming load of glucose and sweeps excess glucose out of the cells.
What is the consequence of insulin resistance?
The early stages of insulin resistance produces impairment of glucose tolerance. This is actually prediabetes.
This means your blood sugars are high after meals but below 200mg/dl (11mmol/l) despite your pancreas’ best efforts. Once your blood sugar rises above 200mg/dl (11mmol/l) 2 hours after meals, that’s type 2 diabetes.
Ultimately, pre-diabetes will progress to type 2 diabetes if undetected. It’s important to point out that insulin resistance precedes type 2 diabetes by over a decade. You could be living with insulin resistance for over 10 years before diabetes complicates it.
The problems of insulin resistance stem from 2 issues:
1. High blood sugar
2. High insulin
Here is how those 2 problems wrap around each other when you have insulin resistance.
They set up a vicious circle. What I call the Insulin resistance vicious circle.
What is this insulin resistance vicious circle?
The insulin resistance vicious circle is triggered by the high blood sugar from prolonged habits of eating sugary foods and refined heavily processed carbs. The high blood sugar provokes a high insulin response.
Over time this high insulin levels (remember the shouting boss?) cause insulin resistance, resulting in high blood sugar which further triggers higher insulin levels leading to yet more insulin resistance and higher blood sugar levels.
…and the circle continues on and on.
They say, a picture is worth a thousand words. So, see images below for clarity.
And how insulin resistance develops
High insulin level is a bad for your metabolic health. Why because insulin is a hormone that not only switches off fat burning but actually encourages fat preservation in the body.
High insulin level also affects your appetite regulation not positively but negatively. Insulin actually makes you feel hungry when the levels are high. So you eat more and pile on the pounds!
Just to make matters worse, high blood insulin levels make you feel tired and sleepy which means you are likely to exercise less. See how insulin resistance causes weight gain here.
That’s not all, high blood insulin level promotes formation of toxic free radicals and other inflammatory agents that lead to metabolic diseases which now fall into the realm of what is now called metabolic syndrome.
I am listing some of the symptoms of insulin resistance below. It is unlikely you will experience all of those symptoms. The problem is that a lot of the symptoms of insulin resistance overlap with “normal” occurrences of everyday life.
That means the symptoms are likely to be overlooked. For the most part, insulin resistance is seen as a symptomless condition but in truth, it has symptoms. It’s just that they are overlooked.
In summary the consequences or symptoms of insulin resistance include:
- high blood glucose
- high insulin levels
- fat preservation and fat storage
- Being overweight or frankly obese as in BMI over 30 especially excess fat in body trunk
- difficulty focusing on tasks
- craving sweets
- reluctance to exercise
- difficulty losing weight
- feeling hungry all the time
- frequent low moods
- high blood pressure
- Acanthosis nigricans – this is a condition that causes dark discolouration of the skin at the back of the neck, the groins and the underarms
- increase in inflammatory agents and toxic free radicals
- ultimately type 2 diabetes and
- metabolic syndrome
Is insulin resistance linked to metabolic syndrome?
Well, insulin resistance is inextricably tied to metabolic syndrome. In fact, metabolic syndrome is also sometimes referred to as insulin resistance syndrome.
The Prevalence of Metabolic Syndrome Amongst US Adults Study revealed that as much as 24% of the adult population in the US have metabolic syndrome using ATP 111 definition. The prevalence of metabolic syndrome exponentially rises with increasing age.
This picture is similar in most western countries especially the ones with a high obesity problem.
Do I have metabolic syndrome or insulin resistance syndrome?
The new ATP 111 definition for metabolic syndrome is this.
You are eligible to be labelled as having metabolic syndrome if you have 3 or more of the following:
- Waist circumference greater than 102 cm in men and 88 cm in women
- Serum triglycerides level of 150 mg/dL (1.69 mmol/L) or higher
- High-density lipoprotein cholesterol level of less than 40 mg/dL (1.04 mmol/L) in men and 50 mg/dL (1.29 mmol/L) in women
- Blood pressure of at least 130/85 mm Hg
- Fasting serum glucose level of at least 110 mg/dL (6.1 mmol/L)
Other conditions linked to metabolic syndrome include:
- polycystic ovarian syndrome
- non-alcoholic fatty liver disease
- chronic kidney disease.
I should stress that it is not a given that everyone with these medical problems will have insulin resistance and likewise, some individuals with insulin resistance do not have these diseases.
But it is wise to know that people with metabolic syndrome have also been shown by population-based studies to have an increased likelihood to die from:
- heart disease
- cancer and
How to test for insulin resistance?
How do I know I have insulin resistance is a question often asked by individuals worried about their health.
It is a valid question and the short answer is your blood is tested for:
- Insulin levels
- Or blood glucose parameters.
So, if you really want to test for insulin resistance, your health professional should be able to arrange blood insulin level or fasting blood glucose tests for you.
Whilst they are at it, they can also check your HbA1C as it gives a broader picture of what your blood glucose levels have been in the last 90 days or so.
Insulin level as a test for insulin resistance is not readily available to most individuals as many labs don’t do the quantitative test for blood insulin. The fasting blood glucose along with the HBA1C should suffice as insulin resistance tests, if your lab is unable to measure blood insulin levels.
If there is doubt with the results (because sometimes unexplainably the HbA1C is not that sensitive in individuals still in the pre-diabetes zone), then the standard Oral Glucose Tolerance Test should be performed. That should nail it!
Now, whilst the HbA1C, Fasting Blood Glucose and the Standard Oral Glucose Tolerance Test (OGTT) give an indication as to whether you may be insulin resistant or not, the interpretation of the result is a little twisted if you like.
We simply assume that if you tested positive for pre-diabetes or frank type 2 diabetes you would have been insulin resistant previously.
It’s a retrospective diagnosis, if you get my drift.
Insulin resistance usually precedes pre-diabetes and type 2 diabetes. That is the sequence of events. You can’t be pre-diabetic or have type 2 diabetes, without developing insulin resistance first. Makes sense?
So how do you interpret HbA1C, fasting blood glucose and Oral Glucose Tolerance Test results?
It’s all well and good when you do the blood tests for fasting, HbA1C or OGTT, but what do they really mean?
Correct interpretation of the results is how you would know you have insulin resistance or gone beyond that to frank diabetes.
So, here we go. Different countries use different units and I have translated the commonly used units in there for you.
What do HbA1C results mean?
Diabetes – 6.5% and higher (47.5 mmol/mol)
Pre-diabetes – 5.7% – 6.4% (38.8 – 47.4 mmol/mol)
Normal – Less than 5.6% (Less than 38.7 mmol/mol)
What do Fasting blood glucose results mean?
Diabetes – 126 mg/dl or higher (7.0 mmol/l or higher)
Pre-diabetes – 100 -125 mg/dl (5.6 – 6.9 mmol/l)
Normal – Lower than 99 mg/dl (Lower than 5.5mmol/l)
What do Oral Glucose Tolerance result mean?
Diabetes – 200 mg/dl and above (11.0 mmol/l and above)
Pre-diabetes – 140 – 199 mg/dl (7.8 – 10.9 mmol/l)
Normal – Less than 139 mg/dl (Less than 7.7 mmol/l)
Adapted from this resource.
For a complete metabolic picture about finding out whether you have insulin resistance or not, you might as well exclude metabolic syndrome. How do you do that? Well you have seen the criteria that tells you about metabolic syndrome above, right?
Why not request a fasting lipid profile as well? That should reveal your blood triglycerides, High density lipoprotein levels (HDL), low density lipoprotein (LDL) levels all of which are important.
If you are lucky the symptoms of insulin resistance may point you in the direction of suspicion, which will lead to blood testing.
One last word about the blood lipid profile:
The best insulin resistance test as I said before is actually the fasting blood insulin levels.
By doing that, we are in fact testing for hyperinsulinaemia i.e elevated insulin levels, which is what characterizes insulin resistance.
We want to know how high the insulin level is without breakfast.
The problem though is, not very many labs can provide that service and those labs providing the service charge an arm and a leg for the test.
The compromise is testing for how well you are dealing with your glucose when you eat (replicated by the oral glucose tolerance test) or what your glucose levels are when you are still fasting or better still your blood HbA1C.
However, as I stated earlier too, when the glucose test and the HbA1C are positive, you are further along the insulin resistance pathway. You have moved on to pre-diabetes or type 2 diabetes depending on what your results say.
So, how can you diagnose insulin resistance a little bit earlier?
Opinion has now shifted to using the lipid profile as a better index of insulin resistance. I am talking about the Triglyceride to High Density Lipoprotein Ratio (TG:HDL ratio). High triglycerides and low HDL are very common in metabolic syndrome.
Therefore, a Triglyceride to HDL Ratio of 3 or more especially if higher than 3.5 is highly suggestive of a long standing insulin resistance. In fact, an abnormal blood lipid test precedes abnormal fasting blood glucose test or abnormal oral glucose tolerance test by several years.
This because in insulin resistance, the fat cells readily accept the glucose, store the glucose as fat and there is a spill over effect. The spill-over effect is fatty infiltration of the liver, the muscle and other organs including the pancreas.
That’s not all. When the liver is making too much fat, some of it spills into the circulation in the form of triglycerides. Hence, high triglycerides in insulin resistance syndrome.
The other advantage is that this blood lipid test is cheaper and more readily available in most labs. If we adopt this cheaper but objective way of diagnosing insulin resistance, we will be catching cases of insulin resistance at a much earlier stage than is currently done…
…and our quality of life will be better for it, because insulin resistance is simply everywhere especially in the over 45s.
Dealing with insulin resistance is essential if you want to optimize your health.
Suggested further reading:
3 Unique Veggies That Fight Abdominal Fat?