Before we move to Insulin Resistance, its important to know what the Insulin is.
What is Insulin
Insulin is a hormone secreted by a long flattened organ in our body called Pancreas located just behind the stomach. The Insulin is a vital part of our digestive system and plays a critical role in controlling blood sugar levels.
The pancreas is made up of clusters of special type of cells called Islets. These Islets contain Beta cells which produce insulin and release it into the blood as when required.
Our body cells get energy from Glucose circulated in our blood stream. As when we eat food, our digestive system warms up and gets to work to digest the food. The digestive tract breaks down the carbohydrates, sugars and starches found in our foods – into Glucose. This converted Glucose enters into our blood stream and circulated throughout the cells of our body so that our body cells can absorb it and use it for energy.
But, for this absorption of Glucose into cells from blood stream, cells need help of Insulin hormone. So as when the glucose is released into our blood stream from digestive tract, the Beta cells of Islets in Pancreas stimulated to make Insulin. Insulin secreted by Pancreas is released into blood stream where it mixes up with glucose and together they circulate throughout the body cells. Insulin helps body cells absorbing glucose from blood stream so that cells can use it for energy.
How Does Insulin Control Blood Sugar
When the glucose is released into blood stream after digestion of food, the blood glucose level raises. When the blood glucose level raises up, the Pancreatic Beta cells are stimulated to produce Insulin. Then this produced Insulin is released into the blood stream where it along with Glucose travels throughout the body cells. Here Insulin performs the following actions:
1. Helps Body Cells Absorb Glucose
Insulin helps body muscle, fat, and liver cells absorb glucose from the bloodstream so that these cells can use the glucose for energy. Thus it lowers the blood glucose level throwing it out of blood stream into the cells.
2. Stimulate Cells To Store Glucose as Glycogen
In our body, extra glucose when not required by cells is stored into the liver and muscle cells as Glycogen. Cells use this Glycogen for energy at a later time as when required.
Insulin hormone stimulates the liver and muscle cells to store excessive glucose as Glycogen so that it could be used at a later time for energy production.
3. Reducing Glucose Production in Liver
Insulin also reduces production of glucose in liver thus helps lowering blood glucose level.
What Is Insulin Resistance?
If everything works well as it is supposed to be in a healthy person, the blood glucose level remains in the normal range.
But, sometimes the body cells stop using Insulin properly and start showing resistance to use Insulin. This behavior of cells to Insulin is known as Insulin Resistance.
Insulin Resistance causes the body cells having trouble absorbing glucose from blood stream. Hence to overcome of this, the body needs higher level of insulin to help cells absorb glucose from blood stream. To keep up with this increased demand of Insulin, the beta cells in pancreas have to work overtime.
The blood glucose level remains in normal range as long as the beta cells are able to keep up with this increased demand of Insulin.
The Worst Part of Insulin Resistance
The Worst Part is that now the things start getting worse with two way attack on this blood glucose management system. First if it is not treated well in time, overtime our body cells become more Insulin resistant.
Second, the overload of working overtime on Beta cells keeps reducing their Insulin production ability and thus the insulin production got reduced overtime.
Gradually due to Insulin resistance and decreased production of required Insulin, the blood glucose is not moved to cells from blood stream properly, so the glucose keeps accumulated into the blood. This accumulation of glucose in blood causes higher level of blood glucose level and leads to many complications overtime.
The normal range of fasting blood glucose level is 70 mg/dL to 100 mg/dL. If the blood glucose levels are between 100 mg/dL and 126 mg/dL this condition is called Prediabetes. If the fasting blood glucose level is more than 126 mg/dL, this condition is called Diabetes.
Insulin Resistance and Prediabetes
Untreated Insulin Resistance leads to development of Prediabetes which is the most dangerous complication of Insulin Resistance not treated well. Often we come to know about it, when it always have been developed to Prediabetes.
Prediabetes is spreading widely in the United States. As per the U.S. Department of Health and Human Services, at least 86 million U.S. adults ages 20 or older were Prediabetic in 2012. (Ref. National diabetes statistics report, 2014. Centers for Disease Control and Prevention website.)
People with Prediabetes are at higher risk of developing type 2 diabetes and other cardio vascular diseases (CVD) which can lead to other serious complications such as kidney failure, heart attack, blindness, stroke and death in many cases. Studies have shown that most of the people having Prediabetes develop type 2 diabetes within 10 years or even less than that, unless they make serious changes in their lifestyle. The lifestyle changes include being physically more active and losing at least 5 to 7 percent of their body weight. People with a Body Mass Index 25 or higher are at risk.
What Causes Insulin Resistance?
Although the exact causes are still subject of researches and not understood well at low level, but at high level the most responsible factors causing insulin resistance are being overweight and living a sedentary life style with lack of physical inactivity. Here are the major contributors to develop Insulin Resistance and Prediabetes.
1. Being Overweight Causes Insulin Resistance
Excess fat especially the belly fat in our body causes development of long lasting or chronic cell inflammation. This chronic inflammation overtime develops the Insulin Resistance in our body cells and eventually leads to develop Prediabetes, Type 2 Diabetes and other Cardio Vascular Disease (CVD).
It has been shown in studies that burning excessive fat and losing weight can increase insulin sensitivity in body cells and thus can reduce insulin resistance.
Excessive fat especially around the waist produces some hormones and other chemical substances. These hormones and substances can cause serious health disorders such as High Blood Pressure, disturbed Cholesterol level, CVD (Cardio Vascular Disease) and most importantly Insulin Resistance, then Prediabetes and eventually Diabetes.
2. Sedentary Life Style and Lack of Physical Inactivity Causes Insulin Resistance
Being physically inactive and lack of doing regular exercise is the another cause of developing Insulin Resistance and Prediabetes. In our body, the muscle cells use more glucose comparatively to other tissue cells. Active muscle cells take energy from Glycogen stored in them.
But if no more Glycogen available to use in cells storage, they tend to refill their Glycogen store taking glucose from blood stream. This process keeps the blood glucose level in balance.
Studies have shown that our muscles become more sensitive to insulin after doing exercise and can reverse Insulin Resistance. Exercise develops more muscle cells in our body and more the muscle a body has, more the glucose it would burn. And more the glucose in cells will burn, more the blood glucose levels will be in balance.
3. Other Causes to Insulin Resistance
There may be some other causes of insulin resistance such as certain diseases, hormones, ethnicity, some drugs, sleep problems, especially the sleep apnea, consumption of alcohol and smoking.
Symptom of Insulin Resistance and Prediabetes
Insulin Resistance often has no signs or symptoms, especially in the early phases. At very initial stage when it starts developing in body, it merely has any symptoms. You could be insulin resistant for years without even knowing unless you don’t get your blood glucose levels checked
When the symptoms start occurring we must have reached a long way with Prediabetes by then. You may however notice the below symptoms when your blood glucose level is higher than normal.
Insulin Resistance Causes Acanthosis Nigricans
There could be a condition called Acanthosis Nigricans associated with Insulin Resistance
in some people. In Acanthosis Nigricans skin gets darken at some body parts and develop dark patches especially at neck, groin, elbow and armpits. It also puts you at higher risk for type 2 diabetes. There’s no treatment for Acanthosis Nigricans, however if you treat the causes such as Insulin Resistance, some of your natural skin color may return.
You may encounter these symptoms below when the Insulin resistance reaches to sever level and starts developing Diabetes. If you encounter these symptoms, this is the red flag signals that your Insulin resistance has reached to the level where you have moved or about to move from Prediabetes to Type 2 Diabetes.
- Increased thirst
- Feeling sleepy and lethargic
- Feeling more hungry than normal
- Losing weight despite eating more
- Frequent urination, especially in night
- Blurred vision
- Feeling tired and fatigue
Read more about Diabetes in my other blog What is Diabetes Mellitus.
How to Diagnose Insulin Resistance
Insulin Resistance is diagnosed as the diagnosis of Prediabetes or Diabetes as these are the progressive stages of Insulin Resistance. There are three tests available to check if you have Insulin Resistance. Normally any one test out of these three is enough to check If you have Insulin Resistance, Prediabetes or Diabetes but in some cases your doctor may suggest any other test depending on test results.
The most recommended test is Fasting Plasma Glucose(FPG) test. Here are the three available tests for blood sugar level:
1. Fasting Plasma Glucose Test (FPGT)
This is the most recommended test to check Insulin Resistance, Prediabetes and Diabetes. In most of the cases this single test is enough to check for Prediabetes and Diabetes.
For FPGT you must be empty stomach since last 8-9 hours. A small blood sample is collected and tested either with Glucometer at home or in lab. Though you can easily perform FPGT at home if you have a Glucometer but you should cross check the results with a test done in medical lab.
There are many Glucometers available in market which you can buy online or offline. However, you should be careful while choosing one and ensure that it has the highest accuracy level. I personally recommend
If you are very specific to price and looking something in less price, you could be with any of these below. These too are not bad and will solve the purpose.
Normal – If blood glucose level is between 70 mg/dL and 100 mg/dL, there is no Insulin Resistance exists.
Insulin Resistance and Prediabetes – If blood glucose level is between 100 mg/dL and 126 mg/dL
Insulin Resistance and Diabetes – If blood glucose level is more than 126 mg/dL
Impaired Fasting Glucose (IFG) – You must have heard a term from doctors i.e. Impaired Fasting Glucose (IFG). IFG is the another term for Prediabetes when the Prediabetes is diagnosed with FPGT (Fasting Plasma Glucose Test).
2. Oral Glucose Tolerance Test (OGTT)
Another test that is used to diagnose Insulin Resistance, Prediabetes or Diabetes is OGGT (Oral Glucose Tolerance Test). This test also require you to be empty stomach since last 8-9 hours. This test determines your body’s glucose tolerance level.
The doctor will test your blood glucose level at the beginning. This involves the same FPGT process as described above.
Then, the doctor will give you a drink of 75 gm Glucose mixture which is a high in sugar. Your blood glucose level is measured again after two hours.
Normal – If blood glucose level is less than 140 mg/dL, there is no Insulin Resistance exists.
Insulin Resistance and Prediabetes – If blood glucose level is between 140 mg/dL and 199 mg/dL, two hours after drinking the glucose mixture
Insulin Resistance and Diabetes – If blood glucose level is above 200 mg/dL in an OGTT, two hours after drinking the glucose mixture
Impaired Glucose Tolerance (IGT) – This is another term you must have head from doctors and generally used for Prediabetes when the Prediabetes is diagnosed with OGTT (Oral Glucose Tolerance Test) test.
3. Hemoglobin A1C (HA1C or Glycated Hemoglobin Test)
This is also called Average Blood Sugar test. This blood test shows the average blood sugar level for past 3 months and performed to diagnose Insulin Resistance, Prediabetes or Diabetes.
Normal – If HA1c level is less than 5.7%, there no Insulin Resistance present.
Insulin Resistance and Prediabetes – If HA1c level is between 5.7% and 6.4 %
Insulin Resistance and Diabetes – If HA1c level is more than 6.4%
Who is at Risk – When to See a Doctor
Insulin resistance has all the risk factors associated with Prediabetes and Diabetes. You should consider having annual screening if you are above 40 or above 35 in some cases when other risk factors present
As the Insulin Resistance and Prediabetes often have no symptoms, it is recommended that you keep your blood glucose level checked regularly if you fall under any of the risk factors associated with Insulin Resistance, Prediabetes and Diabetes given below.
- Lack of Physical Activity and live sedentary life style
- Being overweight and having a body mass index above 25, especially having excessive fat around your belly.
- If your age is 40 or above. But if the other risk factors present, you should get tested even if you are less than 40
- Having diabetic family history
- Had developed Gestational diabetes during pregnancy
- Having Poly cystic Ovary Syndrome
- If blood pressure remains at higher side (Hypertension)
- If Cholesterol levels are imbalanced
- Having high level of Triglycerides
- If belongs to these human races – Hispanic, Indians, African-Americans, Americans, Native Americans, and Asian Americans
Complications of Insulin Resistance
The most dangerous complications of Insulin Resistance is developing Prediabetes and Diabetes. As there are no noticeable symptoms when Insulin Resistance is at initial stage so by the time when symptoms start occurring, most of the people have been moved to end stage of Prediabetes or Diabetes. The major complications include:
- Damage of blood vessels
- Damage to the Kidneys
- High blood pressure
- High Cholesterol level
- Cardiovascular disease
- Heart disease, cardio vascular disease (CVD) and stroke.
- Nerve damage (Neuropathy)
- Alzheimer’s disease.
- Foot problems
- Loss of muscles and weakness.
- Blurred vision and blindness
Prevention and Treatments of Insulin Resistance and It’s Complications
By far we know that Insulin Resistance if not treated, eventually develop Prediabetes and then Diabetes. You can prevent Insulin Resistance from being converted to Prediabetes and Diabetes by losing weight, doing regular exercise and eating a healthy and balanced diet.
Here are the recommendations by American Diabetes Association (ADA) to prevent your Insulin Resistance and Prediabetes from progressing to type 2 diabetes or to completely reverse your Insulin Resistance and Prediabetes to normal.
1. Lose weight
Get started on a weight loss program as soon as you are diagnosed with Prediabetes. Remember diagnosis of Insulin Resistance is measured by the diagnosis of Prediabetes
2. Exercise Regularly
While exercising, it burns the more cell glucose hence moving more glucose out of your blood into the cells. Thus is lowers your blood sugar level.
3. Avoid Oily Food
Omega 6 also called bad fat is an Inflammatory fat in nature and increases Insulin Resistance in body cells. All the oils and butter are rich in Omega 6.
4. Eat Fish
Fish are great source of Omega 3 (also called good fat) which is Omega 3 also called as good fat is an Anti-Inflammatory fat in nature and reduces the Insulin Resistance. Fishes especially the oily fishes are great source of Omega 3.
5. Eat White Meat
Eat only broiled white meat such as chicken breasts which does not have fat.
6. Eat Green Leafy Vegetables
Eat more green and leafy vegetables which are low in carbohydrate.
7. Taking Medications (Metformin)
Sometimes for people who are at very high risk of developing type 2 diabetes, doctor may recommend to take medicine. As per American Diabetes Association Metformin should be the only medication used to prevent type 2. People with higher weight and having higher BMI are at high risk and should be prescribed Metformin. Apart from them a women with a history of Gestational Diabetes should also be prescribed medication.
Metformin reduces production of extra glucose in Liver when it is not needed, thereby keeping your blood glucose level in a better range.
Though you must follow your doctor’s recommendation on Metformin usage and dosage but this article on How to Use Metformin will help you a lot before decide to go with Metformin medication. You must also be aware of side effects of Metformin.
Remember –That diagnosis of Insulin Resistance or Prediabetes is only a warning sign and you can often reverse these early conditions by changing your life style, as suggested.
National Institute of Diabetes and Digestive and Kidney Diseases