Diabetes Mellitus

Diabetes Mellitus Overview and Treatments

Diabetes Mellitus : a group of diseases characterized by high levels of blood glucose resulting from defects in insulin production, insulin action, or both
20.8 million in US ( 7% of population)
estimated 14.6 million diagnosed (only 2/3)
Consists of 3 types:
1) Type 1 diabetes
2) Type 2 diabetes
3) Gestational diabetes

Complications :
- Stroke
- Heart attack
- Kidney disease
- Eye Disease
- Nerve Damage
Diabetes Mellitus
Type 1 Diabetes
- cells that produce insulin are destroyed
- results in insulin dependence
- commonly detected before 30
Type 2 Diabetes
- blood glucose levels rise due to
1) Lack of insulin production
2) Insufficient insulin action (resistant cells)
- commonly detected after 40
- effects > 90%
<>
- eventually leads to β-cell failure
(resulting in insulin dependence
Gestational Diabetes
3-5% of pregnant women in the US develop gestational diabetes

Testing :
Fasting Plasma Glucose Test
(FPG) - (cheap, fast)
*fasting B.G.L. 100-125 mg/dl signals pre-diabetes
*>126 mg/dl signals diabetes


Oral Glucose Tolerance Test
(OGTT)
*tested for 2 hrs after glucose-
rich drink
*140-199 mg/dl signals pre-
diabetes
*>200 mg/dl signals diabetes
A.K.A.: Glycated Hemoglobin tests
A1C

Diabetes - Insulin
Discovered in 1921 by Banting and Best
Consist of A & B chains linked by 2 disulfide bonds
(plus additional disulfide in A)

Diabetes – Insulin(synthesis, storage, secretion)
Produced within the pancreas by β cells  islets of Langerhans
insulin mRNA is translated as a single chain precursor called preproinsulin
removal of signal peptide during insertion into the endoplasmic reticulum generates proinsulin
Within the endoplasmic reticulum, proinsulin is exposed to several specific endopeptidases which excise the C peptide, thereby generating the mature form of insulin

Stored as β granules

Diabetes – Insulin(Biochemical Role)
Tyrosine Kinase
receptors are the locks
in which the insulin
key fits
- Involved in signal
transduction
(insulin hormone being 1st messenger)

In the case of type 1 diabetes, insulin levels are grossly deficient. Thus type 1 diabetes is invariably treated with insulin

Type 2 diabetes is frequently associated with obesity. Serum insulin levels are normal or elevated, so this is a disease of insulin resistance. A number of treatment options may be employed.



REFERENCE:
Animation showing overview of diabetes:
http://www.healthscout.com/animation/1/34/main.html
Animation showing mechanism of action of insulin:
http://www.vivo.colostate.edu/hbooks/pathphys/endocrine/pancreas/insulin_phys.html