Insulin is a hormone secreted into the blood by the pancreas and it assists with controlling your blood sugar levels. When the blood glucose level increases, insulin forces the body cells to take in the extra glucose and use it for energy production. This helps to lower the blood glucose level to a normal range. However in insulin resistance, the insulin is still produced and secreted by the pancreas but the body’s response to insulin is impaired. The cells no longer respond to insulin as they normally would so the body attempts to produce even more insulin.
Since the body cells are not responding to insulin and glucose is remaining in the blood, the blood glucose levels will be elevated. These high blood sugar levels serve as a signal to stimulate the pancreas to produce more insulin, above the normal range. With time, the pancreas is unable to maintain this high insulin level production. It ceases to produce insulin as normal and this leads to type 2 diabetes or ‘sugar diabetes‘.
Pre-Diabetes or IGT
Impaired glucose tolerance, more commonly referred to as pre-diabetes these days, is a stage between a normal glucose tolerance and diabetes. The blood glucose levels are recorded at higher than normal levels but usually thee readings are not a high as in diabetes. If you have impaired glucose tolerance, you will very likely become a diabetic within 2 year of the onset of IGT, unless you identify the cause and make drastic lifestyle changes. This includes losing weight loss, particularly in cases of a ‘fat belly’, switching to low GI (glycaemic index) foods and exercising regularly.
Causes & Complications of Insulin Resistance
Most of the risk factors associated with developing diabetes will also contribute to insulin resistance. These include a family history, being overweight or obese, stress, pregnancy and certain drugs like corticosteroids. However, insulin resistance is also associated with metabolic syndrome, which indicates a link between metabolic disorders and cardiovascular conditions.
Apart from the host of complications associated with diabetes, insulin resistance can also play a significant role in infertility and gynaecological conditions such as polycystic ovary syndrome (PCOS).
Your doctor may consider one or more of the following tests :
- Insulin Test
- Glucose Tolerance Test
If you have high blood glucose levels along with high insulin levels, your doctor can diagnose insulin resistance and take the necessary steps to correct it. However the degree to which your blood glucose is rising will give your doctor an idea of whether you are still in pre-diabetes or have switched into diabetes. The glucose tolerance test will record your blood glucose level at fasting level (no food eaten within 8 hours prior to the first reading) and then a measured dose of glucose is administered orally. Another blood sample is taken after 2 hours.
Under normal circumstances the fasting glucose level will be less 6.1 mmol/l and the 2 hour reading will be less than 7.8 mmol/l.
In a case of impaired glucose tolerance, the 2 hour reading is between 7.8 and 11 mmol/l.
If the fasting reading is between 6.1 and 6.9, yet the 2 hour reading stays less than 7.8 mmol/l, then this is known as impaired fasting glucose or IGF.
In a case of diabetes, the fasting glucose is often 7 mmol/l or more and the 2 hour reading will be 11.1 mmol/l or more.
Treatment & Prevention
Treatment may involve the use of diabetes medication such as metformin. However diet and lifestyle changes should be the main focus. Insulin resistance and pre-diabetes CAN be reversed. Diabetes cannot. A diet of low GI carbohydrates with a moderate calorie reduction, a good physical exercise program and weight loss plan which will allow you to lose 5% of your body weight can significantly improve your status. It can even result in a reversal of your insulin resistance or impaired glucose tolerance. This has been seen is some 60% of patients who strictly adhere to the conservative management plan that their doctor prescribes. Without treatment or management, you will very likely become a diabetic within 2 years.