Signs of Insulin Resistance (Does Your Doctor Know These?)

Insulin resistance is when cells of the body don’t respond properly to the hormone insulin.

Basically, someone who is insulin resistant needs more insulin to have the same impact than someone who is insulin sensitive.

Now, I’ve been a doctor since 2009 and a GP since 2015 and despite the fact that insulin resistance underlies many of our chronic health conditions it’s just not something that is talked about, recognised or addressed until it’s too late.

Table of Contents

Poor Metabolic Health

Insulin resistance is synonymous with poor metabolic health. Metabolic health relates to how the body processes and uses energy from the food we eat.

Sadly poor metabolic health often leads to T2 diabetes, Cardiovascular disease, Alzheimer’s disease and other inflammatory conditions.

It’s a major problem throughout the world. For example – it is thought that only 1 in 8 American adults have good metabolic health.

Sadly the signs of insulin resistance are there for months and even years before a diagnosis of one of these diseases, often going unrecognised by many health professionals.

So, what if we could recognise some of the indicators of insulin resistance, identify what the problem is and therefore resolve them before we develop these chronic states of really poor health.

So let’s get started…. They are not in any particular order of occurrence, it’s a bit of ‘pot-luck’ as to which signs an individual will demonstrate, so make sure you read until the end.

Central Obesity

Excess fat stores are never healthy in the long term but fat stored around the middle…what we call ‘central obesity’ is specifically associated with Insulin Resistance.

When your body is producing lots of insulin in response to the food you are eating, as it is trying to stabilise your blood glucose levels, the excess glucose that is not immediately needed for energy has to be stored somewhere.

The ability to store excess food is a survival process genetically passed down from generations before who had to endure long periods of food deprivation. Just like prehistoric Pete…

The ability to lay down fat stores to call upon for energy when food was scarce during winter months enabled man to survive.

However, for most people there is never a time of food scarcity, we are constantly laying down fat stores for a winter that never comes.

As we continually overload the body with excess foods, in particular sugar and carbohydrates we exceed our subcutaneous fat stores (the capacity for which is different for everyone) and overspill into storing fat in and around our central organs, our liver and pancreas….

Signs of Insulin Resistance

It becomes a vicious cycle of high insulin causing fatty deposits in this area, the more fat we have here the more it becomes resistant to the effects of insulin. This leads to higher insulin levels and more fat storage.

The Insulin resistance that happens in the liver then means that the liver doesn’t have an ‘off’ switch for producing its own glucose and continues to release more into the bloodstream which already has too much!

It is well documented that fatty deposits in and around our organs cause damage over the long term. There are clear links with the development of Type 2 diabetes, Cardiovascular Disease and hypertension.

Tape Measure Around Waist
So from a practical point of view…. Consider where do YOU store fat? Is your waist more than half your height? … this is a good indicator of whether you are building visceral fat or not. Sadly many medical practitioners only consider your Body Mass Index (BMI)…. which is just not a good assessment of whether your fat stores are harmful or not.

Elevated Blood Glucose

Your blood glucose or sugar level should be closely maintained between 4-7mmols/L (or 72-126mg/dl). When working well your insulin production works to keep these levels stable regardless of what you have eaten by enabling glucose to be moved in and out of your blood , going out of storage when we haven’t eaten and into storage when we have.

If you have a check at your doctors, it is likely that you will have had your HbA1c checked… this gives a very useful guide to your average Blood glucose levels over approx 3 months and is used to diagnose diabetes.

However, long before you have an abnormal HbA1c your fasting blood glucose levels can be raised, indicating Insulin Resistance in the liver. Fasting levels are usually taken first thing in the morning when you have had nothing to eat or drink except water for at least 10-12hrs before the test.

This is easy to check yourself with a home blood glucose monitor. These are available from most large pharmacies and even supermarkets.

The other thing you can check with a blood glucose monitor is your blood glucose response to food. Check before you eat and 2 hours after…. You can check in between as well…to get the full picture. Your Blood Glucose at 2 hours should be back to baseline of between 4-7. If it takes longer to come down then this can also be an indicator of Insulin Resistance.

Cholesterol/ Lipids

When you get a “lipid panel” or your cholesterol checked this measures much more than simply your ‘cholesterol’. Actually, it doesn’t measure your cholesterol levels at all… but that’s for another post!

Sadly many Doctors still just advise patients on the basis of their total cholesterol numbers or their LDL levels (often referred to as ‘bad’ cholesterol).

However, part of the diagnostic criteria for metabolic syndrome (and therefore Insulin Resistance) as set by various bodies such as the World Health Organisation doesn’t actually mention LDL at all. Instead, the important markers are;

  • a HDL (often referred to as the ‘good’ cholesterol) of less than 1.03 for males and 1.29 for females and a
  • Triglyceride level of over 1.7mmol/L.

It is the ratio between either triglycerides and HDL or the ratio between HDL to total cholesterol that indicates Insulin Resistance and your risk for Cardiovascular disease.

You want to aim for a higher HDL level and a lower Triglyceride level to have lower risk.

So why do so many doctors focus on LDL and don’t address low HDL or Raised Triglycerides…

various medications spilling onto the table

The answer is STATINS … the drugs for lowering cholesterol ….

Statins only work to reduce LDL, they don’t work against the actual cause of heart disease.

Despite their best efforts pharmaceutical companies haven’t ever been able to produce a drug that raises HDL. So the well researched and well documented criteria for Cardiovascular disease risk that were developed off the back of massive studies (such as in the Framington Heart Study) just kind of …well… gets ignored.

So next time you get your lipids checked… ask for your HDL and triglyceride levels so that you can get a true picture of your risk.

Fatty Liver Disease

Fatty liver can be caused by excessive alcohol consumption, however there is a huge growing problem around the world of Non Alcoholic Fatty Liver Disease (NAFLD).

It is thought that a staggering 25% of the adult population worldwide has NAFLD.

It can be picked up by a US scan of the abdomen, but central obesity is a strong indicator (with 80-90% of obese adults having fatty liver disease).

It can also be indicated by some abnormal Liver function blood tests (however normal liver function tests don’t mean that you don’t have fatty liver disease).

Sadly this fatty infiltration of the liver’s tissues can often be ignored by medics as not being a serious issue, and almost expected if the person is overweight.

I have to hold my hands up and admit that back when I was training, I can recall seeing a patient who had been diagnosed with fatty liver disease on an ultrasound scan. Because at that time I didn’t really understand the link between nutrition and fatty liver disease I simply assumed that the patient was drinking far more alcohol than he was admitting too.

The problem is that a fatty liver… is an unhappy liver.

Fatty liver causes insulin resistance and therefore Type 2 diabetes and Cardiovascular disease.

It is also a leading cause of liver cancer and cirrhosis.

Like many signs of Insulin Resistance, the problems lie undetected for possibly years before a disease diagnosis…. In the words of Prof Roy Taylor

‘Before diagnosis of Type 2 diabetes, there is a long silent scream from the liver.’

What is even more difficult to hear about is the ever increasing numbers of children being diagnosed with fatty liver. You only have to look at the growth of child obesity to understand how this is happening.

Blood Pressure

Hypertension, or high blood pressure is a huge issue, both as part of disease processes such as Cardiovascular disease, Kidney problems and also as a stand alone disorder.

It is usually labelled as ‘essential hypertension’, where the word essential… basically means don’t really understand the cause, or it is put down to ageing.

Signs of Insulin Resistance

Now, ageing of course does have an effect on blood vessels and heart function which can lead to raised blood pressure.

However, I really do believe that Hypertension is a clear sign of Insulin resistance for many.

There are several reasons for this;

  • High insulin levels cause the retention of salt (sodium) instead of it being excreted in the urine. With sodium comes water retention which means more volume of fluid and raised BP
  • High insulin and raised blood glucose causes inflammation and damage to the lining of blood vessels, making Hypertension and Cardiovascular disease more likely
  • Obesity and Insulin resistance cause increased leptin levels (leptin being our hunger hormone) which causes a reduction in the amount of uric acid being excreted in the urine
  • Fructose consumption also increase uric acid levels
  • Uric acid is a natural waste product, but when it’s not excreted levels can build up in the body, causing gout, kidney stones and Hypertension.

‘An elevated serum uric acid is also one of the best independent predictors of diabetes and commonly precedes the development of both insulin resistance and diabetes type 2’Rashika El Ridia and Hatem Tallimaa 2017

High Blood pressure is defined as being equal to or higher than 140/90, although an optimal reading would be 90/60- 120/80 (definitions as per NHS).

So if you haven’t done so recently, perhaps get a check on your blood pressure. … know your level, then you can take action.

These first 5 symptoms of Insulin Resistance are all markers of poor Metabolic health. If you have 3 or more of them then you have Metabolic Syndrome (MS) and your risk is much greater for the diseases associated with Metabolic Syndrome…. Type 2 diabetes, cardiovascular disease etc.

The next 2 are perhaps even less well known for their association with Insulin resistance but are nevertheless potential indicators.

Skin Conditions

We’ve talked about the effects of insulin on blood glucose, and on the kidneys but Insulin is also a growth stimulating hormone. It is no wonder that it’s effects will be seen across our biggest organ… our skin.

It can be easy for us doctors to see skin problems as an isolated issue.

However, we need to see many skin issues as a reflection of what’s happening internally.

I certainly wasn’t aware until I started my weight loss journey that Insulin resistance has links with so many skin conditions and I’ve had loads of messages from clients whose skin conditions have cleared up!

And before I take you through the following skin conditions I’m not saying that these are caused by insulin resistance, or that everyone who has these skin conditions has insulin resistance. What I’m saying is that we, as doctors, when we encounter these conditions should start to think about what is going on beneath the skin that may help us pick up insulin resistance earlier.

Skin Tags

These are often seen as small fleshy growths in the creases of skin around the neck or the armpit. Stimulated by an overgrowth of skin due to the effects of excess insulin.

Acanthosis nigricans

Signs of Insulin Resistance

Seen as thickened, velvety patches of skin, again seen around the neck and armpits most commonly. Another example of skin overgrowth stimulated by excessive insulin production.

Hidradenitis Suppurativa

This is a painful, long-term skin condition that causes abscesses and scarring on the skin. Usually occurs around hair follicles in areas of sweat glands such as groin, armpit, buttocks, under the breasts.

Signs of Insulin Resistance

We have a protein in the body called mTor which is a regulator of cellular growth. This is stimulated by food intake. Over stimulation typically by the Western diet and also puberty is linked with excessive insulin release which can lead to these painful cysts.

The same is also associated with:

Acne Vulgaris

Typically seen in adolescents. A symptom of hormonal changes , possibly aggravated by our Western diet causing overgrowth and inflammation in the skin.


This is well documented in the scientific literature as being associated with Type 2 diabetes risk and poor metabolic health. However this is not something I recall being discussed with patients presenting with psoriasis, or checked for underlying metabolic problems.

Signs of Insulin Resistance

The reddened, scaly patches of skin are driven by a systemic inflammatory response. The inflammation is associated with the cytokine release as part of our immune system being triggered. It is known that we can have an excessive cytokine release from fat cells . Cytokines are part of our immune response, which is vital at times of infection. However, like many things.. Too much can be a bad thing.


Thrush is a fungal skin infection that can occur in the mouth, warm skin crease areas such as the groin & breast, and also the genitals.

Candida is the name of the fungus and usually our immune system can deal with it. However it will thrive when there is an ample supply of glucose, particularly if our immune system is compromised. We know that Insulin resistance can lead to raised Blood glucose levels, and this excess of glucose will be found in sweat, saliva and our urine and so feed the infection in these areas.

Poor Skin Healing

If you have had a traumatic skin wound , and I don’t necessarily mean a major one, that has been really slow to heal…. This too can be a sign of insulin resistance. If you remember the chronic inflammation that occurs as a result of persistently raised insulin and also from the cytokines released from fat cells. Well, whilst inflammation is a necessary part of wound healing, if it doesn’t settle down then new skin cells are unable to form. Additionally too much glucose can cause bacterial growth and feed infection and further delay healing, or worse lead to a more widespread infection.

Reproductive Health

PolyCystic Ovarian Syndrome (PCOS)

PCOS is the most common cause of female infertility. The ovaries are sensitive to insulin. Too much exposure to insulin prevents the conversion of testosterone to oestrogen (which is a normal process), so there is not enough oestrogen to signal the release of an egg each month. So the partially mature eggs get retained in the ovaries which appear as cysts. Without the release of an egg…. There will be no pregnancy.

The higher levels of testosterone cause the male signs of PCOS; coarser facial and body hair, male pattern baldness.

It is now commonly treated with metformin , a diabetic drug, because it helps to improve insulin sensitivity. And yet most medics don’t associate the symptoms and treatment with Insulin resistance. I’ve yet to meet a woman with PCOS who had been advised about the link between her diet, insulin resistance and her condition.

Have you suffered from PCOS? Did you know it was related to Insulin Resistance?

Gestational Diabetes

Pregnancy is a state of natural insulin resistance. It allows the woman to lay down some fat stores to ensure she has adequate energy supplies to nurture the growing baby. This should then return to normal after pregnancy.

Gestational diabetes happens when that natural insulin resistance becomes deranged and blood glucose levels become too high. This is usually associated with pre-pregnancy obesity and family history. Women are then at a higher risk of pregnancy later in life.

Low Testosterone

Higher body fat percentages in men can cause low testosterone levels. This is because fat tissue (adipose tissue) contains an enzyme aromatase. This enzyme converts testosterone to oestrogen. The more fat tissue, the more aromatase and the more oestrogen you have which means less testosterone. Low testosterone can affect sperm production and is a cause of infertility in men. This can also affect a man’s energy levels, sex drive and muscle strength.

Erectile Dysfunction

As well as low testosterone levels, which can affect erectile function, insulin resistance can also affect the dilation of blood vessels. For the same reasons as hypertension, the reduced dilation of blood vessels can cause erectile problems. So the possibility of insulin resistance should be explored in patients in the absence of other known causes of this issue.


So we have had a look at the many and varied signs of insulin resistance. What it really tells us is that too much insulin leading to resistance causes widespread problems that present as different external signs. Individuals may exhibit one or many of these signs.

If you recognise any of these in yourself, then now is your chance to take action and improve your health before you develop any of the more sinister consequences of poor metabolic health.


Obesity and insulin resistance 

Obesity, Bioactive Lipids, and Adipose Tissue Inflammation in Insulin Resistance 

Association of Insulin Resistance, Plasma Glucose Level, and Serum Insulin Level With Hypertension in a Population With Different Stages of Impaired Glucose Metabolism

Banting Memorial Lecture 2012. Reversing the twin cycles of Type 2 diabetes. Taylor, R. Diabetic Medicine. 2012

Triglyceride is independently correlated with insulin resistance and islet beta cell function: a study in population with different glucose and lipid metabolism states (2020) 

Association of Non-alcoholic Fatty Liver Disease with Metabolic Syndrome Independently of Central Obesity and Insulin Resistance

Approach to Pediatric Obesity and Nonalcoholic Fatty Liver Disease

The pathogenesis of insulin resistance: integrating signaling pathways and substrate flux 

COVID-19, adaptative immune response and metabolic associated liver disease

Epidemiology of non-alcoholic and alcoholic fatty liver diseases 

Obesity, Hypertension, and Insulin Resistance

Hypertension and Insulin Resistance Adam Whaley-Connell, James R. Sowers . 2009 

Physiological functions and pathogenic potential of uric acid: A review

Metabolic Syndrome and Skin Diseases – 

Hidradenitis Suppurativa Associated With Insulin Resistance

Insulin Resistance and Skin Diseases

Diabetes and its impact on wound healing Sharp, A. Clark, J. (2011) Nursing Standard. 25, 45, 41-47.

Evaluation of lipid ratios and triglyceride glucose index as risk markers of insulin resistance in Iranian polycystic ovary syndrome women

Erectile dysfunction may be the first clinical sign of insulin resistance and endothelial dysfunction in young men