You may have heard the term insulin resistance before, and that it can be a cause for concern, namely as its relation to conditions like diabetes and obesity. But what exactly is this condition, and how does it develop in the body? Let’s review the anatomy of insulin resistance and the risk factors for developing it.
What is insulin?
Insulin is a hormone made by the pancreas which helps the body use glucose, aka sugar, for energy. When we eat food, namely carbohydrates such as bread, rice, cereal, pasta, sweets, as well as fruit and some vegetables, it turns to glucose in the bloodstream. The rise in blood sugar signals the pancreas to release insulin, which allows the sugar in the blood to enter the body’s cells, such as fat and muscle cells. Then the “sugar” can be used for energy right away, stored shorter term as glycogen in the muscles or longer term as fat.
How the body produces and regulates insulin
The pancreas
An organ located in the abdomen, behind the stomach and near the upper small intestine, has two major functions in the body, helping with digestion by making and releasing enzymes and regulation of energy balance and metabolism by creating and releasing hormones. The beta cells of the pancreas make insulin to help lower blood sugar when levels are too high. The alpha cells of the pancreas release another hormone called glucagon which helps increase blood sugar levels if they get too low.
The liver
An organ that is also located in the abdomen and involved in blood sugar and metabolism. The liver plays a key role in glucose storage. When blood sugar rises after eating a meal, the liver takes up the glucose and stores it as glycogen. The liver can break the glycogen back into glucose to release it back into the bloodstream in response to low blood sugars.
Together, the liver and pancreas help to keep a balance of blood glucose and insulin, produced in the right amounts to both fuel cells and maintain glycogen storage.
Insulin resistance
Insulin resistance is a condition where the body is unable to use its own insulin efficiently since the muscle, liver and fat cells do not respond properly. When the body’s cells do not respond accordingly to insulin, glucose cannot enter the cells and remains in the bloodstream. As a result, the pancreas works harder as it needs to produce more and more insulin to help glucose get into the cells. Once the pancreas is no longer able to keep up with insulin demand, blood glucose can stay elevated enough that prediabetes or even diabetes develops.
Risk factors for developing insulin resistance
The main causes and risk factors for insulin resistance include:
- Being overweight/obese
- Age 45 and older
- Family history of insulin resistance/prediabetes/diabetes
- Physical inactivity
- Smoking cigarettes
- Health conditions such as high blood pressure and abnormal cholesterol levels
- A history of gestational diabetes
- A history of heart disease or stroke
- Polycystic ovary syndrome, also called PCOS
- other things such as taking certain medicines, hormonal disorders and problems with sleep
Symptoms of insulin resistance and diagnosis
Often people who have insulin resistance do not have any symptoms at all and it is commonly discovered through bloodwork at a physical exam. As insulin resistance progresses symptoms may include feeling tired, more hungry/thirsty, accumulation of fat in the abdominal area and darkening of the skin in the armpits, back or sides of the neck. While there is no routine test for insulin resistance your doctor may consider factors such as family and medical history, any signs and symptoms and findings on your physical exam and may order tests to check your blood sugar levels such as fasting blood sugars, or a hemoglobin a1c which reflects average blood sugar over several months.
How is insulin resistance managed?
Lifestyle modifications are often the first steps towards managing insulin resistance. These include:
- A sensible diet of whole fresh foods and less processed foods, focusing on plenty of non-starchy vegetables, lean proteins such as poultry, fish, low fat dairy and beans as well as controlled portions of high fiber starches, fruits and unsaturated fats like nuts, avocado and plant-based oils
- Regular physical activity, aiming for a minimum of 150 minutes of moderate intensity exercise per week
- Maintaining a healthy weight by working with your healthcare team to determine the ideal weight for you and losing weight if needed
- Focusing on other important lifestyle habits such as stress management and adequate sleep
Learn more about ways to manage insulin resistance and improve insulin sensitivity in our previous post.