Aug 19, 2012

Diabetes Mellitus and Diabetes Insipidus

The two types of diabetes : diabetes insipidus and diabetes mellitus
They differ in many ways. Though they share common name, ‘diabetes’, the reasons behind them and most of the symptoms are different. Diabetes mellitus is the most common of the two, as it is a lifestyle disease that affects metabolism in our body. The increased incidence of sedentary life, tensions, and decrease in physical activity are mostly to be blamed, though some other reasons such as auto-immune disease also are causes. Some severe head injuries, tumours, or certain diseases can result in diabetes insipidus.

Here is more about diabetes insipidus and diabetes mellitus and the differences between them.
What is diabetes insipidus?
Due to some injuries or viral diseases, the hypothalamus or pituitary gland get damaged and might be rendered unable to produce the hormone vasopressin or ADH. In some, the kidneys might have defect or be damaged due to certain reasons resulting in inability to respond to vasopressin/ADH. This lack of vasopressin/ADH or inability to respond to vasopressin causes the body to lose water through excessive urination. This is known as diabetes insipidus.

What is diabetes mellitus?
Diabetes mellitus varies from diabetes insipidus mainly in the hormone involved. When it comes to diabetes mellitus, the hormone involved is insulin, secreted by pancreas, which is absorbed by the cells in our body as a message to use glucose present in the blood. When pancreas is unable to secrete insulin or when the cells in our body develop resistance to insulin, the glucose in the blood will not be utilised. This is known as diabetes mellitus.

What are the differences between diabetes mellitus and diabetes insipidus?
  • The Hormones Involved
In diabetes insipidus, it is the lack of vasopressin /ADH or inability of kidneys to respond to it, which is synthesised by hypothalamus in the brain and released by pituitary gland present nearby.
Where as in diabetes mellitus, the hormone insulin, which is secreted by the cells in pancreas present near the stomach, is either deficient or the body is unable to respond to it.
  • What is in excess?
In those who are suffering from diabetes insipidus, excess urination results in increasing the concentration of salts or electrolytes present in the body. This is known as hypernatraemia.
In diabetes mellitus, since the body cannot process the glucose present in blood, there is either excess glucose present in the blood or very low levels of glucose present in blood because of physical activity or insulin intake, though this is when there is no proper control of blood sugar and health.
  • The Reasons for Polyuria
Polyuria is one of the symptoms of both diabetes mellitus and diabetes insipidus.
But, the reason for the symptom polyuria in diabetes insipidus is the kidneys do not either receive the anti-diuretic hormone (ADH) or they are unable to respond to it. This inhibits the kidneys ability to reabsorb water into bloodstream to prevent dehydration.
The symptom polyuria in diabetes mellitus is due to the presence of excess glucose in blood, a situation known as hyperglycaemia. The kidneys then try to discard this excess glucose through urination, resulting in polyuria.
  • Other Differences in Symptoms
In diabetes insipidus, the symptom polydipsia is due to frequent urination or because of damage to thirst mechanism, whereas, in diabetes mellitus, it only occurs when there is hyperglycaemia. Polyphagia is a symptom of diabetes mellitus, but, is not seen in diabetes insipidus.

Though it may seem difficult to cope with diabetes and be optimistic about the treatment, there are many in the world, suffering from diabetes insipidus and diabetes mellitus, who have taken their lives into their hands and started working on themselves to get healthy and better quality of living. Proper nutrition and good physical activity, with treatment and medication in the right time can always make life happier and easier.

Ta ta......


Nelson Lim said...

Sir, will you mind to share with me some notes, trial exam questions and preparation short notes to help me up in preparing for my STPM Biology?