Articles
Insulin Resistance
What Is Insulin Resistance?
Insulin is the hormone responsible for moving sugar into the body cells where it is used for energy. This helps to regulate the level of glucose (sugar) in our blood. In some people, the body cells do not respond to the insulin. This is called insulin resistance. As the glucose does not move freely into the cell, our blood concentration of glucose increases.
It is thought that around one in four people show signs of insulin resistance.
Who Is Susceptible?
You may be susceptible to insulin resistance if you have one or more of the following:
- A close family member with diabetes (sibling, parent, grandparent)
- You have a history of diabetes during pregnancy
- You are overweight or obese
- You have a history of Polycystic Ovarian Syndrome
- You suffer from chronic stress
- You have more fat deposited around your waist than your hips (waist/hip ratio)
- You have a higher than normal blood glucose level (but not diabetic)
- You are a smoker
- You have a poor diet that is high in fat and high glycaemic index foods.
There is some evidence to suggest a deficiency in magnesium and/or chromium may be a precursor
Testing For Insulin Resistance
Insulin resistance can be determined with a simple fasting blood test.
For fasting insulin levels, current guidelines indicate:
- < 10 normal
- 10-14 Mild to moderate insulin resistance
- >14 moderate to severe insulin resistance
Insulin levels may also be checked during a Glucose Tolerance Test (GTT). Levels of 100 or more at 1 or 2 hours show severe insulin resistance.
Effects Of Insulin Resistance
When body cells become resistant to insulin, the pancreas over produces insulin to try to compensate. The resulting hyperinsulinaemia is the major factor behind insulin resistance syndrome. Abnormalities resulting from insulin resistance, such as changes in glucose and lipid metabolism predispose to diseases such as diabetes, cardiovascular disease and hypertension. This is termed insulin resistance syndrome or syndrome X. This can also result in fatty liver (nonalcoholic steatohepatitis).
Hypertension
Hypertension is also common due to enhanced sodium retention by the kidney and stimulation of sympathetic nervous system activities.
Obesity
Obesity is strongly linked with insulin resistance. This is mostly due to insulin’s effect of promoting the production of fat (lipogenesis) and the development of adipose tissue. Alternatively, obesity is also a major factor in the development of insulin resistance.
Cardiovascular Disease
There is an increased risk of cardiovascular disease. This is usually accounted for by obesity, hypertension and changes to the lipid profile. Often the insulin tends to increase blood triglyceride levels and decrease HDL (good cholesterol) levels.
Hormone Imbalance
The hyperinsulinaemia also affects other hormones. In particular there is an increase in androgens. This can result in acne, Polycystic Ovarian Syndrome, infertility and hirsutism.
Diabetes
Finally, there is a greatly increased risk of developing diabetes. The excessive production of insulin by the pancreas to compensate for the insulin resistance can cause the pancreas to fail to cope with the continued production and lead to diabetes.
Non-alcoholic Steatohepatitis (NASH)
Inflammation and fat build-up in the liver can lead to fatty liver or steatohepatitis. This appears to often be present in Insulin resistance in combination with obesity, heart disease and diabetes.
What is the treatment for insulin resistance?
- Achieve and maintain a healthy body weight. This involves balancing food intake with energy output. Having a low fat/low kilojoule diet and doing regular physical activity.
- Consume low glycaemic index foods. These foods result in a slower increase in blood sugar levels over a period of time resulting in a sparing effect on insulin requirements.
- Consume a low fat, low sugar and high fibre diet. Include breads and cereals (preferably wholegrain), fruit and vegetables, lean meat and low fat dairy products.
- Be a non-smoker
- Look at ways to alleviate stress
- There may be a need for drug therapy. These medications are typically used to manage blood glucose levels in people with diabetes but are also very effective with insulin resistance eg Metformin.
Long term implications
The increased blood sugar level is a strong precursor to diabetes. Cardiovascular disease may also result from hypertension, altered lipid metabolism and obesity. Other problems that may arise are a fatty liver and infertility.
Added to site on : Monday, 21 October 2002