Insulin, a hormone made by your pancreas, allows your cells to use glucose for energy. Some people suffer from insulin resistance, a condition in which cells are incapable of using insulin effectively. The cells have difficulty absorbing glucose, which causes an abundance of sugar in the blood. When this occurs, your blood glucose levels increase. If your blood glucose levels are higher than normal, but not high enough to be diagnosed with type 2 diabetes, you have a condition called pre-diabetes.
Insulin resistance can lead to type 2 diabetes, stroke, fatty liver, and Arteriosclerosis (also known as Atherosclerosis), a process of progressive thickening and hardening of the walls of medium-sized and large arteries.
What is Insulin Resistance?
Insulin is a hormone produced by the beta cells of the pancreas. These cells are located throughout the pancreas in small clusters known as the Islets of Langerhans. The insulin produced here is released into the blood stream and travels the body.
Insulin is an essential hormone that has many functions within the body. Most actions of insulin are directed at metabolism control of carbohydrates (sugars and starches), lipids (fats), and proteins. Insulin also regulates the functions of the body’s cells, including their growth. Insulin is vital for the body’s use of glucose as energy.
Insulin resistance (IR) is a condition in which the body’s cells become resistant to the effects of insulin. When this occurs, the normal response to a given amount of insulin is reduced. Subsequently, higher levels of insulin are needed in order for insulin to have its proper effects, and the pancreas compensates by trying to produce more insulin. This resistance occurs in response to the body’s own insulin or when insulin is administered by injection.
With insulin resistance, the pancreas produces increased amounts of insulin until the pancreas can no longer produce sufficient insulin for the body’s demands, and then blood sugar rises. Insulin resistance is a risk factor for development of heart disease and diabetes.
Risk Factors for Developing Insulin Resistance
Obesity. Men and women with a Body Mass Index (BMI) more than 25 kg/m2 are at a higher risk of developing IR. Scientists believe that hormones produced in fat stores are a precipitating cause of insulin resistance. You can calculate your BMI by taking your weight (in kilograms) and dividing by your height in meters squared.
Stress. When we are stressed, our bodies produce hormones in response to the perceived threat. Cortisol, one of the hormones released from the adrenal glands, suppresses the production of insulin, leading to IR.
Pregnancy. During pregnancy, the placenta that supplies your growing baby with nutrients and oxygen also makes hormones. In late pregnancy, the hormones Estrogen, Cortisol, and Human Placental Lactogen can block insulin, causing insulin resistance to develop.
Old Age. The science behind age-related insulin intolerance is not yet completely clear. The interaction of many factors associated with aging likely contributes to the reduction of glucose tolerance in this population. Decreased physical activity, medications, coexisting illnesses, and insulin secretory defects associated with the aging process are all potential contributing factors to developing IR later in life.
Symptoms of Insulin Resistance
For many people, insulin resistance often doesn’t trigger any noticeable symptoms, especially in the early phases. You could be insulin resistant for years without knowing, especially if your blood glucose levels aren’t checked. Some IR symptoms to watch for include:
Skin tags. A skin tag is a common, benign condition where a bit of skin projects from the surrounding skin. Skin tags vary significantly in appearance. A skin tag may appear smooth or irregular, flesh-colored or darker than surrounding skin, and either be simply raised above surrounding skin or hang from the skin.
Acanthosis Nigricans. This condition creates dark patches on the back of the neck, groin, and armpits. It also puts you at higher risk for type 2 diabetes. There is no known cure for acanthosis nigricans, but if you treat the causes, some of your natural skin color may return.
Polycystic Ovarian Syndrome. PCOS is a common hormonal problem which affects menstruating women. It is an endocrine disease in which the body does not respond as quickly to the production of insulin. The sluggish response will cause larger and larger amounts of insulin to be required before glucose is taken into the body tissues. Eventually this buildup causes a change in the way the body deals with sugar.
People with IR often report extreme thirst and hunger, as well as an increased urgency to urinate. Insulin resistance may also damage your blood vessels without you realizing it. This can increase your risk of heart disease and stroke. If you have insulin resistance, you are at significant risk for progressing to diabetes. The symptoms of type 2 diabetes can be mild, so you may not know you have the condition until a doctor runs diagnostic tests on you.
Diabetes symptoms include:
- Extreme thirst or hunger
- Feeling hungry even after a meal
- Frequent or increased urination
- Tingling sensations in your hands or feet
- Feeling more tired than usual
If you are not displaying any obvious symptoms, your insulin resistance, pre-diabetes, and diabetes can be detected with a blood draw. Testing for diabetes should begin at about age 40, along with the usual tests for cholesterol and other markers of health. Ideally, you can get tested at your annual physical exam or preventive screening with your primary doctor. Earlier testing may be recommended if you are overweight and you:
- Live a sedentary lifestyle
- Have low good (HDL) levels or high triglyceride levels
- Have a parent or sibling with diabetes
- Are American-Indian, African-American, Latino, Asian-American, or Pacific Islander
- Have high blood pressure (140/90 mm Hg or above)
- Were diagnosed with gestational diabetes
- Had a baby who weighed more than 9 pounds
Even if your test comes back in the normal range, you should have your blood glucose levels checked every two to three years.
Preventing Insulin Resistance
If you have any of the risk factors of developing insulin resistance, it is a very good idea for you to take proactive steps to help you avoid the disease. Here are some suggestions:
- Eat a diet high in vegetables and fruits. Choose fruits and vegetables that offer an array of colors for the best nutrients, such as cantaloupes, carrots or tomatoes. Avoid vegetables that contain starch, such as corn. Instead, eat green vegetables like spinach, broccoli or green beans.
- Exercise regularly to help prevent insulin resistance. Aim for moderate activity for at least 2 1/2 hours a week. Find activities that will raise your heart rate, such as walking or jogging, and incorporate resistance training, such as weightlifting, into your routine. You may start out slowly, even exercising in 10-minute increment
- Check your blood pressure regularly. Blood pressure levels above 130/85 may put you at risk for insulin resistance. If you have high blood pressure, consult your doctor for exercise and diet solutions to lower the numbers. Your doctor may also prescribe medication to regulate your blood pressure, thus lowering your risk of insulin resistance.
You may be able to prevent insulin resistance by exercising daily and eating a balanced diet. Losing weight and keeping it at a healthy level is the best way to get your blood glucose levels in the desired range. It is important to remember that a diagnosis of insulin resistance or pre-diabetes is only a warning. You can often reverse these early conditions with healthy lifestyle choices.