Diabetes- Causes and Types
Today we will try to learn the pathology[reason, disease] behind getting diabetes and the different types of DM.
A] Pathophysiology of Diabetes:-
Have a look at these pictures shown below:-
These two pictures show a gland in the abdomen called pancreas which contains special cells in a part called Islet of Langerhan. These cells are named as the Beta [ β]-cells and the Alpha [α]-cells.
β- cells produce a hormone called Insulin which controls sugar [glucose] levels in the blood by pushing it into different tissues in our body to produce energy for the cells of the tissue.
α- cells produce a hormone called Glucagon that helps in releasing glucose in the blood circulation whenever there a drop in blood glucose levels. In other words, these two hormones regulate blood sugar levels.
There is a balance in the action of the above two mentioned hormones and this helps in maintaining the blood sugar level.
The normal blood glucose range is as follows:-
a] Fasting:- i.e early morning blood sugar level as soon as we get up:-70 to 120 mg/ml
b] Postprandial:- meaning the blood sugar level after 2 hours of having a meal:- up to 140mg/ml
The lack of insulin or the dysfunction of insulin receptors in various parts of the body raises the blood sugar level. This is termed hyperglycemia. Persistent hyperglycemia- a level above 200 mg/ml after a meal- if not controlled by diet and exercise leads to diabetes.
How does this actually happen?
The reasons are many, and a few important ones are as given below:-
This is inherited from parents wherein there is a total absence of insulin in the body;
This is due to inflammation 0r infection of the pancreas due to viral or bacterial disease;
3] Autoimmune disease:-
This is due to antibodies -substances that act against the cells in our body-formed against pancreatic cells[which destroys the β-cells] and/or insulin receptors on target tissues like muscle, fatty cells, etc.
4] Central obesity:-
This is the accumulation of fats around the central part of the body-the trunk- that leads to a condition called insulin resistance;
5] Tumors of the pancreas;-
Tumour or cancerous growth in the pancreas destroys the insulin-secreting cells of the pancreas.
Alcohol consumption can lead to the accumulation of fats in the liver causing fatty liver. Sometimes vomiting after taking alcohol can cause it to backflow in the pancreatic duct and then the pancreas itself. This also destroys pancreatic cells to some extent.
B] Types of Diabetes:-
We will now learn about different types of DM. They are:-
1] Type 1:-
This is also known as Insulin-dependent DM because there is a total absence of insulin in the body and external insulin has to be administered. Reason no. 1 & 3 are the main causes of this type of DM.
2] Type 2:-
This is also known as Maturity onset, wherein there is sufficient insulin but it is not able to push glucose into the target cells[muscles, liver, fatty tissue]. Reasons no. 2,4,5 and 6 cause this type of DM.
3] Intermediate type/Prediabetes:-
This is also known as Impaired Glucose Tolerance or Pre-diabetes. The cause is mostly obesity.
4] Gestational DM[Diabetes of pregnancy]:-
This is present in some women due to physiological changes that take place in the body during pregnancy and are mostly reversible. Sometimes the high blood sugar levels persist even after delivery and this can lead to Type 2 diabetes.
Having understood the cause and types of DM, we will now learn about the signs and symptoms and investigations of diabetes in Part 3 and 4 of this series.
By now, you must have fully understood the basics of diabetes.
If you have any doubts or suggestions, feel free to contact me on my email firstname.lastname@example.org.