Block 9 - L5-L6 Flashcards
(143 cards)
What is diabetes mellitus?
Metabolic disorder characterized by hyperglycemia caused by a defect in either - insulin production, insulin responsiveness, or a combination of the two.
Normally, what does insulin do?
Increases glucose uptake into cells
What happens in Type I DM?
Insulin-producing beta cells are destroyed via autoimmune causes, leading to insulin deficiency. Glucose cannot be taken up into the cells because there is no insulin to bind to the cells and trigger this process.
What is the general form of treatment used for DM1?
Insulin replacement therapy
What happens in Type 2 DM?
Insulin resistance leads to a decreased insulin response and an inability to take up glucose
What is the general form of treatment used for DM2?
Insulin sensitizers, insulin secretagogues, insulin/other drugs
How is high glucose regulated normally?
High glucose activates the release of insulin from beta cells of the pancreas. Insulin causes increased glucose uptake in the liver; increased glucose uptake, TG synthesis, decreased lipolysis, and decreased FFA/glycerol in adipose tissue; increased glucose uptake, amino amino acid synthesis, and glycogen synthesis in muscle; all leads to decreased glucose
In addition, the alpha-cells are inhibited from releasing glucagon, which normally causes increased gluconeogenesis and glycogenolysis in the liver.
What are the symptoms of DM 1?
Polyuria, polydipsia, glucosuria, unexplained weight loss despite polyphagia, fatigue, blurred vision, ketoacidosis in some cases
What are the symptoms of DM 2?
Obesity, fatigue, polyuria and polydipsia, though patients are often asymptomatic; IFG and IGT can be detected and precede the onset
What are the normal fasting plasma glucose, 2 hour peak postprandial plasma glucose, and HbA1c levels?
- <100 mg/dL
- <140 mg/dL
- <6.0%
What are the pre-diabetic fasting plasma glucose, 2 hour peak postprandial plasma glucose, and HbA1c levels?
- 100-125 mg/dL
- 140-199 mg/dL
- n/a
What are the diabetic fasting plasma glucose, 2 hour peak postprandial plasma glucose, and HbA1c levels?
- > 126 mg/dL
- > 200 mg/dL
- > 6.5%
What are the pretreatment goal fasting plasma glucose, 2 hour peak postprandial plasma glucose, and HbA1c levels?
- 90-130 mg/dL
- <180 mg/dL
- <6.5%
What is the major side effect of intensive therapy to treat DM?
Increased risk of hypoglycemia
What is the only treatment for DM 1?
Insulin replacement therapy; required for both glycemic control and survival
What is the goal of insulin replacement therapy?
Replicate the normal physiological production of insulin by the pancreas
What are the two types of insulin produced physiologically in the pancreas?
- Basal insulin (produced under fasting conditions)
2. Postprandial insulin (produced in response to each meal)
Describe the MOA of insulin.
Insulin acts through its plasma membrane cell surface tyrosine kinase receptor.
- Inhibits secretion of glucagon in the liver (inhibits hepatic glucose production)
- Stimulates glucose uptake via upregulation of the GLUT4 glucose transporter in the muscle and adipose tissue
- Promotes amino acid uptake and protein synthesis in muscle (blocks flow of gluconeogenic precursors to the liver)
- Inhibits lipolysis and promotes TG storage in adipose tissue (also prevents flow of gluconeogenic precursors to the liver and reduces energy substrate for gluconeogenesis)
List the 4 categories of commercially-available insulin preparations.
- Rapid-acting
- Regular
- Intermediate acting
- Long-acting
List the rapid-acting insulin preparations.
- Insulin aspart
- Insulin lispro
- Insulin glulisine
List the intermediate-acting insulin preparations.
- NPH insulin (isophane)
List the long-acting insulin preparations.
- Insulin glargine
2. Insuline detmir
Compare the onset of the 4 categories of commercially-available insulin preparations.
- Rapid-acting: 5-15 minutes
- Regular: 30-60 minutes
- Intermediate acting: 1.5-2 hours
- Long-acting: ~2 hours
Compare the peak of the 4 categories of commercially-available insulin preparations.
- Rapid-acting - 45-75 minutes
- Regular - 2-4 hours
- Intermediate acting - 6-10 hours
- Long-acting - no peak