Diabetes Mellitus It is characterized by hyperglycemia (high blood sugar level), glycosuria (glucose in urine), polyuria ( increased volume of urine due to the osmotic effect of glucose), polydipsia (excessivie thirst), polyphagia (excessive appetite). It is due to the hyposecretion of insulin or lack of insulin.
It is of two types:- Diabetes Type I and Diabetes Type II.
Diabetes Type I (Insulin Dependent Diabetes Mellitus, IDDM): It is cased due to deficient insulin production by pancreas because either beta cells of islets of Langerhans are not able to produce insulin or beta cells are absent.
Diabetes Type II (Insulin Independent or Non insulin Dependent Diabetes Mellitus, NIDDM): It is an inherited recessive autosomal disorder appearing after the age of 40 years in which the cells fail to take up insulin from blood. It results in deficient passage of glucose form blood into the cell surfaces for storage or for direct consumption. It may occur due to defective insulin receptors over cell surfaces or abnormality on plasma protein amylin. The phenomenon is called insulin resistance. This type of diabetes mellitus accounts for 80-90% of all cases of diabetes.
It is kept under control by administration of insulin in case of insulin dependent diabetes. and hypoglycaemics in case of insulin independent diabetes. Sugar free diet is a pre requisite in both the cases.
Diabetes Insipidus (Drinker’s disease): Hypo secretion of ADH (Antidiuretic hormone or Vasopressin) causes a disorder known as diabetes insipidus (Excretion of large quantity of dilute urine). ADH is released into blood when special osmoreceptors or hypothalamic neurons are stimulated by rise in osmotic pressure of blood due to loss of water from the body.
In this disorder, person suffers from polyuria, i.e., excessive urine formation and dilute urination (hypotonic and sugar free) several times a day. The quantity is 5 litres or more per day. There is corresponding increase in water loss from body fluids. It results in excessive thirst or polydipsia and dehydration. Appetite increases. Loss of strength and emaciation occur.
Diabetes Mellitus vs Diabetes Insipidus
|It is a pancreatic disorder.||It is hypothalamic disorder.|
|It is due to deficiency of insulin availability to cells.||It is caused by deficiency of ADH|
|There is rise in blood glucose level or hyperglycaemia.||No rise in blood sugar level.|
|Glucose is excreted along with urine.||Glucose is not excreted.|
|The urine is of normal concentration.||The urine is very dilute.|
|Urine output is excessive.||Urine output is enormous.|
|Blood cholesterol level often rises.||Blood cholesterol level does not rise normally.|
|There is excessive eating.||Hunger is normal.|
|Ketone bodies occur in blood and urine.||They do not occur in case of Diabetes insipidus.|