Insulin Resistance (HOMA)
Insulin is a hormone that is produced by the beta cells of the pancreas. Its actions are directed at metabolism (control) of carbohydrates (sugars and starches), lipids (fats), and proteins as well as regulating cell growth.
In insulin resistance (IR) – which can happen at any age – the cells of the body, particularly the muscle and fat cells, become resistant to insulin causing the pancreas to make more of the hormone. This increases the level of insulin in the blood and can cause insulin resistance that can be measured and calculated by the HOMA index.
What is the HOMA Index?
The HOMA index (Homeostatic Model Assessment of insulin sensitivity) is a calculation based on the levels of serum fasting glucose and fasting insulin, with insulin resistance defined as a HOMA index of >3.0.
The Lab results for IR include the level of fasting Glucose, fasting Insulin, HOMA (I.R.), the percentage of Beta cell activity and the Sensitivity of Insulin (a measure of cells’ reduced sensitivity to insulin).
What causes Insulin Resistance?
There are several causes of insulin resistance including some medications (such as steroids). However there is thought to be a strong genetic (inherited) factor as well. It is only in recent years that insulin resistance has been gaining importance in its own right and as a contributor to the Metabolic Syndrome (see below). Furthermore, insulin resistance may precede the development of Type 2 Diabetes. IR is generally seen in the following conditions:
The Metabolic Syndrome, which consists of a group of disorders such as obesity, lipid abnormalities (low HDL and high LDL), high blood pressure & smoking. Patients with this syndrome are usually overweight, with a Body Mass Index (BMI) of more than 25, and a waist of more than 101.6cm in men and more than 88.9cm in women.
- General Obesity
- Stress (including fatigue or depression)
- Pregnancy or Polycystic Ovarian disease
- Fatty Liver
- Heart Disease including arteriosclerosis (hardening of medium and large arteries).
What are the Symptoms of IR?
Some of the following symptoms may be seen in patients with IR:
- Fatigue (sometimes physical, but often mental).
- Inability to focus
- High blood sugar
- Intestinal bloating. Insulin resistance sufferers who eat carbohydrates sometimes suffer from gas.
- Sleepiness immediately after eating a meal containing more than 20% or 30% carbohydrates.
- Weight gain, fat storage, difficulty losing weight (with increased blood triglyceride levels).
- Increased blood pressure
How can I manage Insulin Resistance?
Insulin resistance can be managed in two ways. First, the need for insulin can be reduced, and second, the sensitivity of cells to the action of insulin can be increased. While there is sometimes a genetic component, insulin resistance can usually be managed with:
Diet: such as adding Flavanol containing food (e.g. cocoa beans, dark chocolate, red fruits and tea) since they decrease IR.
Exercise: as it reduces weight and improves the sensitivity of cells to insulin.
Medication: such as Glucophage (by doctor prescription only) as it prevents the liver from releasing glucose into the bloodstream, and increases the sensitivity of muscle and fat cells to insulin so that they remove more glucose from the blood.