Diabetes Mellitus (DM) Flashcards
2 key Hormones of the pancreas?
Specifically where and which cell type produces them?
produced in the islets of Langerhans
- A cells produce glucagon;
- B cells produce insulin
What is insulin
an anabolic hormone, that is, it increases the storage of gluco, fatty acids and amino acids in cells and tissues.
What is glucagon?
a catabolic hormone, that is, it mobilizes glucose, fatty acids and amino acids from stores into the blood.
Important effects of Insulin
Insulin causes cells in the liver, skeletal muscles, and fat tissue to take up glucose from the blood. Inhibits gluconeogenesis in the liver and muscle cells.
What regulates insulin production
Blood glucose levels
Others….?
How is glucose stored?
In the liver and skeletal muscles, glucose is stored as glycogen, and in adipocytes it is stored as triglycerides..
Where is glucose metabolized? Does it always need to cross the cell membrane to be used?
I don’t know
General description of diabetes
- Disorder of insulin (I) action and/or secretion
- Causes widespread metabolic issues- beyond carbohydrates (CHO) also proteins and lipids
• Absolute deficiency= no insulin OR relative deficiency is = low levels
o Compromised glucose homeostasis
• Complications:
o CV, ocular, renal, neuro are chronic
o Acute
o Life threatening if uncontrolled
Micro and macro vascular complications
Macrovascular: stroke, heart disease and HTN,
peripheral vascular disease, ulcers and amputations
Microvascular: diabetic eye disease retinopathy and
cataracts, renal disease, neuropathy, foot problems
What is Prediabetes?
is the state in which some but not all of
the diagnostic criteria for diabetes are met. It is often described as the “gray area” between normal blood sugar and diabetic levels.
What typifies pre diabetes in Diagnotics?
• IFG (impaired fasting glucose) – 6.1-6.9 mmol/L
o Measured after 10hrs of fasting (below 5.5 is normal)
• Hb [alc] (6-6.4%) of glucose nound to Hb
• IGT (glucose tolerance) 7.8-11 mmol/L
o After fasting glucose test, drink some glucose and watch how levels decrease- if abnormally normal decrease of glucose post peak- decreased tolerance
What is metabolic syndrome
Predisposes to Type 2 DM and Cardio Vascular disease
Several Characteristics:
- abdominal obesity (diabesity: abdominal circumference female >35”, male >40”)
- HTN
- Hyperlipedemia
- IFG
- IGT
- Insulin resistance
What is insulin resistance?
Body does not use insulin effectively.
Muscle, fat, and liver cells do not respond properly to insulin and thus cannot easily absorb glucose from the bloodstream. As a result, the body needs higher levels of insulin to help glucose enter cells
Cells are less sensitive to insulin, require more insulin to do the same job.
Stop looking deeper!
Difference in prevalence between Type 1 and 2
• Type 1 (~10%) Always absolute insulin deficiency (historically called IDDM)
• Type 1 A
o immune based,
o more prevalent ~90% of type 1]
o immune targeting of beta cells
• Type 2 o idiopathic (~90%) (NIDDM), relative insulin insufficiency
Etiology / Genetic components of Type 1
o Strong genetic influence- familial influence (x10 inc risk with one person who has it in your fam)
o Insulin gene Chr 11 (10% of folks with type 1)
• The gene regulate division and fx of beta cells
o MHC genes on Chr 6 (40%)
NOTE: MHC gene codes for proteins that sit on cell surface and identify them as self. Beta cells with mutated MHC may be targeted in autoimmunity
What are the islets of langerhans?
are the regions of the pancreas that contain its endocrine (i.e., hormone- producing) cells. Human islets display alpha and beta cells in close relationship with each other throughout the cluster.
What is insulitis
inflm of islets of Langerhans because of infiltration of T cells
When and how is insulin being inhibited in Type 1?
Type 1
• Usually early age onset
• Autoimmune issue (90-95%)
o Genetic predisposition
o Enviro trigger (virus?)
• Immunity destroys beta cells (up to 90%)
o Absolute I deficiency
o Destroyed by t cells
o or antibodies
• islet cell auto antibodies production
• Insulin auto AB production
