Exam 4: Endocrine Part I (bri/jia) Flashcards
A normal glucose level requires a balance btw ____ and ____ of dietary carbohydrate intake
glucose usage and endogenous production
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____ is the primary source of endogenous glucose production via glycogenolysis & gluconeogenesis
The liver
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70-80% of the glucose released by the liver is metabolized by insulin-insensitive tissues such as the _____, _____, and _____.
brain, GI tract, and red blood cells
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____ hours after eating, when glucose usage exceeds production, a transition from exogenous usage to endogenous production occurs to maintain a normal plasma glucose level
2-4
During this time, diminished insulin production is fundamental for the maintenance of normal blood glucose
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what hormones comprise the glucose counterregulatory system and support glucose production
glucagon, epinephrine, growth hormone, and cortisol
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Glucagon plays a primary role by stimulating____, and inhibiting ____.
Stimulates: glycogenolysis &gluconeogenesis
Inhibits: glycolysis
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Diabetes mellitus is the most common endocrine disease
and affects ____ in 10 adults
1
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DM results from an inadequate supply of ____ and/or an inadequate ____.
- insulin
- tissue response to insulin
- This leads to increased circulating glucose levels with eventual microvascular and macrovascular complications
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Type 1a diabetes is caused by a T-cell–mediated autoimmune destruction of ____ within pancreatic islets, leading to ____circulating insulin levels
- β cells
- minimal or absent
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Type 1b diabetes is a rare disease of absolute insulin deficiency, which is not ____.
immune mediated
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Type 2 diabetes is also not immune mediated and results from defects in ____ and post-receptor ____ signaling pathways
- insulin receptors
- intracellular
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Type 1 DM
- Accounts for ____% of all DM cases
- Usually diagnosed before age ____
- Exact autoimmune cause of type 1a is unknown
- A long pre-clinical period (____) of B-cell antigen production precedes onset of symptoms
- At least ____% B cell function is lost before hyperglycemia ensues
- 5-10%
- 40 yo
- 9-13 yrs
- 80-90%
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Hyperglycemia over several days/weeks is associated w/
- fatigue
- weight loss
- polyuria
- polydipsia
- blurry vision
- hypovolemia
- ketoacidosis
Type 2 DM
- accounts for >____% DM cases
- Increasingly seen in younger pts & children over the past decade
- Very underrecognized, normally present ____ years before diagnosed
- > 90%
- 4-7 years
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In initial stages of type 2 DM, insensitivity to insulin on peripheral tissues leads to
↑pancreatic insulin secretion
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as DM progresses ____ function decreases and ____ levels become inadequate.
- pancreatic function decreases
- insulin levels become inadequate
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3 main abnormalities seen in DM2
- ↑hepatic glucose release caused by a reduction in insulin’s inhibitory effect on liver
- Impaired insulin secretion
- Insufficient glucose uptake in peripheral tissues
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DM2 is characterized by insulin resistance in?
skeletal muscle, adipose & liver
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Causes of insulin resistance include:
- Abnormal insulin molecules
- Circulating insulin antagonists
- Insulin receptor defects
- Obesity and sedentary lifestyle are acquired and contributing factors
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Diagnosis for Type 2 DM
- fasting blood glucose
- HbA1c
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Diagnosing prediabetes or diabetes
- normal HbA1C?
- PreDM HbA1C?
- DM HbA1C?
- normal HbA1C: < 5.7%
- PreDM HbA1C: 5.7-6.4%
- DM HbA1C: >/= 6.5%
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what are the 4 steps from the american DM association criteria for the diagnosis of DM?
- A1C >6.5%: the test should be perfomed in a laboratory using a method that is NGSP certified and standardized to the DCCT assay
- FPG?126mg/dL (7mmol/L) Fasting is definied as no caloric intake for at least 8hr
- 2-hour plasma glucose greater than/equal to 200mg/dL during an OGIT. the test should be performed as described by the WHO using a glucose load containing the equivalent of 75g dissolved in water
- In a pt with classic symptomes of hyperglycemia or hyperglycemic crisis, a random plasma glucose greater than or equal to 200mg/dL (11.1mmol/L)
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Treatmeant for DM2
- dietary adjustments
- exercise/weight loss
- PO antidiabetic drugs
- insulin
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how does exercise and weight loss treat DM2?
Decreasing body fat improves hepatic & peripheral insulin sensitivity
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what are PO antidiabetic drugs?
- metformin
- sulfonylureas
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What is metformin and how does it treat DM2?
- A biguanide, preferred initial drug tx
- Enhances glucose transport into tissues
- ↓TGL & LDL levels
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how do sulfonylureas treat DM2?
- Stimulate insulin secretion
- Enhances glucose transport into tissues
- d/t diabetic progressive loss of B cell function, Sulfonylureas not effective long term
- SE’s include hypoglycemia, weight gain & cardiac effects
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What is the initial therapy and additional therapy for DM2?
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____ is necessary in all DM1 cases and 30% of DM2 cases
insulin
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what are the different types of insulin?
- Rapid acting (Lispro, Aspart) provide glucose-control @ mealtimes
- Short acting (regular)
- Basal/Intermediate acting (NPH, Lente)
- Long acting (Ultralente, Glargine)
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- what is the most dangerous complication of long acting insulin?
- what exacerbates this complication?
- Hypoglycemia is the most dangerous complication
- ETOH, metformin, sulfonylureas, ACE-I’s, MAOI’s, Non-selective BB’s
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- Repetitive hypoglycemic episodes lead to “____”
- Pt becomes desensitized to hypoglycemia and doesn’t show ____ sx
- ____ ensues→fatigue, confusion, h/a, seizures, coma
- Tx: ___
- hypoglycemia unawareness
- autonomic
- Neuroglycopenia
- TX: O or IV glucose (may give SQ or IM if unconscious)
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Short Acting inslulin
What is onset, peak and duration of:
* Human regular
* lispro [humalog]
* aspart [novolog]
Human regular
* O: 30 min
* P: 2-4 hr
* D: 5-8 hr
lispro [humalog] & aspart [novolog]
* O: 10-15 min
* P: 1-2 hr
* D: 3-6hr
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Intermediate Acting Insulin
What is onset, peak and duration of:
* human NPH
* Lente
- human NPH and Lente
- O: 1-2 Hr
- P: 6-10 Hr
- D: 10-12HR
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Long acting insulin
What is onset, peak and duration of:
* ultralente
* glargine (lantus)
- ultralente
- O:4-6hr
- P 8-20hr
- D:24-48hr
- glargine (lantus)
- O: 1-2 hr
- P: n/a
- D: 24hr
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this is a complication of decompensated DM with a mortality of 1-2%. It is more common in DM1 often triggered by infection or illness.
Diabetic Ketoacidosis
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DKA: high glucose exceeds the threshold for ____ reabsorbtion which creates ____ and ____
- renal reabsorbtion
- creates osmotic diuresis and hypovolemia
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Tight metabolic coupling of ____ & ____ leads to liver overproduction of ketoacids
gluconeogenesis & ketogenesis
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DKA results in excessive glucose-counterregulatory hormones, with glucagon activating lipolysis & free fatty acids which causes
substrates for ketogenesis
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what are the diagnostic features of DKA?
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What is the treatment for DKA?
- IV volume replacement
- insulin
- correct acidosis w/ sodium bicarb
- electrolye supplement [K+, phos, mag, Na+]
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when treating DKA what is the loading dose of insulin and what is the infusion rate?
- Loading dose 0.1u/kg Regular
- low dose infusion @ 0.1u/kg/hr
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What happens if you correct glucose in DKA but dont correct sodium?
Correction of glucose w/o simultaneous correction of sodium may result in cerebral edema
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this is characterized by severe hyperglycemia, hyperosmolarity & dehydration and normally occurs in DM2 >60 y/o.
Hyperglycemic Hyperosmolar Syndrome
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Hyperglycemic Hyperosmolar Syndrome eveolve over days to weeks with persistent ____.
glucosuric diuresis
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