I recently went for a full medical check up. The doctor told me I was overweight and my fasting blood glucose came back high. The doctor said that I wasn’t a diabetic yet, but I was heading that way if I didn’t do something about it. He mentioned that I had insulin resistance. What is insulin?

Insulin is a hormone that is produced by your pancreas, an organ that is located just behind your stomach. Your pancreas contains many cells that are clustered in little islets. There are certain islet cells called beta cells. These produce insulin and release it into the bloodstream.

Insulin is an extremely important hormone that controls the body’s metabolism. Once you consume food, your gastrointestinal tract breaks down the carbohydrates into glucose. Once glucose enters your bloodstream, insulin production is triggered.

How does insulin affect the glucose in my bloodstream?

When insulin is produced and released into the bloodstream, it signals the liver, and muscles and fat cells all around the body, to absorb the glucose in the bloodstream. This glucose is then used to produce energy for your body’s daily activities.

Basically, insulin helps the uptake of glucose by the body’s cells, thus reducing the glucose level in the bloodstream. Some cells don’t require insulin to take up glucose on their own, but most require insulin’s help.

If the body’s cells “decide” that they don’t need the glucose, then insulin will signal the liver to take in the extra glucose to be stored as glycogen. The liver can store up to 5% of its mass as glycogen.

Insulin production is very regulated. It helps the body keeps its blood glucose level from rising too high (hyperglycaemia) or too low (hypoglycaemia). If the blood glucose level is high, there will be a spike of insulin being produced and released to the blood, and vice versa.

Insulin resistance, high blood glucose, diabetes, pre-diabetes, testing for diabetes, Star2.com

In prediabetes, the fasting blood glucose level is between 6.1 and 6.9mmol/l. — AFP

Does insulin affect only glucose?

No. Insulin has many other functions, such as:

• Helping amino acids (by-products of protein breakdown) enter muscles to repair them, as well as other cells.
• Helping the uptake of fats into fat cells.
• Helping excrete sodium and fluid into urine.

Think of insulin as your big storage hormone.

The doctor said that I have insulin resistance. What is this?

This means that the cells in your body – muscle, fat, liver – do not respond properly to the insulin that is circulating in your bloodstream. Therefore, glucose cannot be properly absorbed by your cells, leading to higher glucose levels in your bloodstream.

Your pancreas then needs to produce even higher levels of insulin in order for sugar, fats and proteins to enter your cells. As long as your pancreas can do this, your blood sugar will be kept in the normal range.

However, your cells may get even more resistant to insulin over time. Your poor pancreas has to keep on producing even higher amounts of insulin to keep your blood glucose regulated.

In the end, your pancreas will just not be able to keep up anymore, and your blood glucose will rise. This is called pre-diabetes.

Insulin resistance, high blood glucose, diabetes, pre-diabetes, glycogen, liver, converting glucose to glycogen, Star2.com

Excess glucose is stored in the liver as glycogen. The liver can store up to 5% of its mass as glycogen. — TNS

What is the difference between having pre-diabetes and diabetes?

In pre-diabetes, you do not have symptoms. Here, you have a high blood glucose level, but it is not high enough for you to be diagnosed as having diabetes. Pre-diabetes almost always precedes diabetes.

Why do I have insulin resistance and pre-diabetes?

It is very likely that you are overweight. Obesity, especially being fat around your waist, is the primary cause of insulin resistance.

You see, belly fat is not just stored in your belly. Belly fat produces hormones and other substances that cause insulin resistance and other problems like high blood pressure and chronic inflammation.

You need to get rid of that belly fat! And it’s not just by reducing your sugar and calorie consumption. You need to exercise as well. After exercising, your muscles become more sensitive to insulin, helping them absorb more glucose to burn for energy.

For a start, try walking 30 minutes a day, five days a week, if you can’t progress to the higher physical activity levels yet. You also need to have adequate and good quality sleep. If you keep your weight down to a healthy level and exercise regularly, you can reverse your insulin resistance and pre-diabetes.


Dr YLM graduated as a medical doctor, and has been writing for many years on various subjects such as medicine, health, computers and entertainment. For further information, e-mail starhealth@thestar.com.my. The information contained in this column is for general educational purposes only. Neither The Star nor the author gives any warranty on accuracy, completeness, functionality, usefulness or other assurances as to such information. The Star and the author disclaim all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.