Medical Guides

What is Insulin and What is Its Role in the Body?

Insulin is a hormone produced by the pancreas. After a meal, the glucose levels in the blood rise. In response to raised blood glucose level, the pancreas produces insulin, which helps in the entry of glucose into the cells. A part of this glucose is used to produce energy and the remaining is stored as glycogen, in liver and muscles. Insulin thus helps the entry of glucose into the cells and in the storage of glucose as glycogen. Insulin is also needed to synthesise protein and store fats.
What is Diabetes Mellitus?

Diabetes Mellitus is a syndrome characterised by persistently high levels of blood sugar along with disturbances of carbohydrate, fat and protein utilisation in the body. It is associated with absolute or relative deficiency of insulin secretion and/or insulin action.

A simple definition of diabetes would be – a disease in which the body is unable to properly use and store glucose – causing the blood glucose or ‘sugar’ to rise higher than the normal range.

High blood sugar is the hallmark of diabetes.

What is High Blood Sugar?

Fasting blood sugar of more than 126 mg % or random blood sugar more than 200 mg % signifies diabetes. A fasting blood sugar between 100 – 126 mg % is considered borderline high.

How Does Diabetes Mellitus Occur?

Diabetes occurs due to deficiency in the action of insulin. In diabetic patients, there is either a decrease in the insulin secretion (deficiency) or a decreased response of the peripheral tissues to insulin (inefficiency).The glucose is unable to enter the cells due to improper action of the cells and the blood glucose level rises (hyperglycaemia). The cells are starved, as glucose is not entering the cells. Therefore, the body produces more glucose by two ways.

(a) First the glycogen stored in the liver is broken down to liberate glucose (this process is called glycogenolysis).

(b) Next, the proteins in the body are broken down into amino acids, which are, then, converted in the liver to glucose (this process is called gluconeogenesis). The blood glucose in diabetes thus rises because of the following reasons:

1. Decreased entry of glucose into the cells because of insulin deficiency

2. Breakdown of glycogen

3. Breakdown of body proteins and conversion of amino acids into glucose

The first mechanism is most important.