Definition : Metabolic disorder characterized by i. hyperglycemia
ii. glycosuria
iii. hyperlipaemia
iv. negative nitrogen balance
v. sometimes ketonaemia
Pathological changes are also handing with this.Therefore this is one of the very important diseases to have a knowledge of.
Pathological changes
- Thickening of basement membrane of capillaries.
- cellular proliferation.
- vessel wall matrix increase.
- lumen narrowing.
- Atherosclerosis.
- sclerosis of glomerular capillaries.
- Retinopathy.
- Neuropathy.
- Peripheral vascular insufficiency.
There two major types of Diabetes mellitus.
1. Type I ( Insulin dependant DM ,Juvenile onset DM )
In pancreas there are cells called beta cells which is specifically designed to secrete insulin.Here those beta cells are destroyed and depending on the cause , there are again two types.
i. Type 1A - Autoimmune disease which destroys beta cells.
ii. Type 1B - Idiopathic ( cause is unknown)
However this type 1 is less common.
2. Type II ( non-insulin dependent DM , maturity onset DM )
Here beta cells are normal. We can't exactly say whether the insulin in blood is low or high.But if we check antibodies which destroy beta cells,those are undetectable.Unlike Type I , genetic predisposition is very high. This type is resulted due to one of following causes.
- Gluco receptors on the islets cells only respond at higher glucose concentration.so If the glucose concentration in the blood increases adequately to have diabetes,still insulin production is attenuated.
- Peripheral tissues are less sensitive to insulin.therefore If the insulin production is normal, it does not help still.
- Excess of hyperglycemic hormones.(Glucagon.
