Quiz 2: Diabetes and Cardiac Flashcards
Who secretes insulin in response to glucose intake?
pancreatic beta cells
Type 1 diabetes:
acute onset of insulin deficiency, requires exogenous insulin administration
Type 2 diabetes:
more gradual onset which causes insulin uptake in cells to be impaired and slower destruction of beta cells in pancreas
Hemoglobin A is what percent of total Hgb?
98%
Hemoglobin A1 is what percent of Hemoglobin A?
7%
What are the three components of Hemoglobin A1:
A1a, A1b, A1c
Hemoglobin A1c makes up what percent of A1?
80% of A1
The average A1c is what?
5.6%
If you measure TOTAL hemoglobin A1 it is generally x% higher than just the hemoglobin A1c component?
2-4%
Hemoglobin A1c is the component of hemoglobin A1 that combines…
most easily and strongly with glucose
Non diabetic adult or child A1c
4-5.6%
Diagnosis of diabetes A1c:
> 6.5%
Our goal in patient care is to keep the diabetic patient’s HbA1c under?
7.0%
What is the average lifespan of a RBC?
100-120 days
HgbA1c percentage can be used to determine the patient’s glucose level over what period?
3-4 month
Mean plasma glucose:
(35.6 x HgbA1c) -77.3
Mean plasma glucose shows what?
uses hemoglobin A1c to let our patients know what their average daily glucose reading is
1% reduction in HbA1c reduces risk by what percent? Diabetes related deaths
21%
1% reduction in HbA1c reduces risk by what percent? MI
14%
1% reduction in HbA1c reduces risk by what percent? Microvascular complications
37%
1% reduction in HbA1c reduces risk by what percent? amputations or deaths
43%
Insulin is produced in?
pancreatic beta-cell
Insulin release facilitates the moment of glucose from?
circulatory system to the cell
When is insulin level helpful:
detection of an insulinoma or to find cause of hypoglycemia
Why is insulin level of the blood not always reflective of pancreatic beta-cell function?
it undergoes significant first pass metabolism by liver
Increased insulin:
insulinoma, obesity, early type 2 diabetes
Decreased insulin:
insulin-dependent diabetes (type 1 generally)
What is C-peptide?
a connecting protein
What does C-peptide connect?
the alpha and beta chains of proinsulin, which is the precursor of insulin
The chains of proinsulin separate in the?
beta cells of the Islet of lnagerhans within the pancreas
What is C-peptide useful for?
cause of hypoglycemia and distinguishing type 1 for type 2 diabetes
Does synthetic insulin contain c-peptide?
no
c-peptide in Type 1 diabetes:
low c-peptide
c-peptide in type 2 diabetes:
Normal or high c-peptide
Pancreatitis results from:
long term alcohol use or binge drinking, gallstones, trauma to pancreas, drug-induced
When is amylase ordered?
in the evaluation of abdominal pain and is specifically used to detect pancreatitis
Amylase is secreted from:
acinar cells of the pancreas
Amylase is involved in the catabolism of?
carbohydrates
When damage occurs to the acinar cells, amylase “pours out” into:
lymphatic system, free peritoneum, and circulatory system
Amylase level can return to normal within x hours of onset of illness or trauma, because it’s rapidly cleared by kidneys
12 hours
What can cause persistently elevated levels of amylase?
persistent or severe disease
Amylase increased in:
acute pancreatitis, chronic pancreatitis, pancreatic cancer, bile duct obstruction by gallstone, cholecystitis, renal failure, ectopic pregnancy, mumps
Aside from the pancreas, amylase can be found in:
Fallopian tubes, salivary glands, gallbladder
Lipase is used to diagnose:
pancreatitis in the evaluation of abdominal pain
Lipase is secreted by the
pancreas into the duodenum
Lipase is involved in the catabolism of:
triglycerides into fatty acids
Lipase is excreted via
kidneys
Who is lipase’s partner in crime?
amylase
Lipase often parallels rise in amylase, but may rise…
a little later and sticks around a little longer (5-7 days)
Lipase is useful to diagnose pancreatitis at:
a later stage
Uric acid is the end byproduct of:
purine nucleotide catabolism
Purines and pyrimidines are building blocks of?
DNA
Sources of purine include:
diet, degradation of nucleotides or endogenous synthesis of new purines
Uric acid that results from purine catabolism is primarily excreted by
kidneys but also by intestinal tract
Uric acid elevated in:
high purine diets, alcohol abuse, cancer, renal failure, dehydration caused by diuretics
Uric acid levels are frequently elevated in:
gout
High levels of uric acid is called
hyperuricemia
At levels >6.5 mg/dl, uric acid can be deposited into:
joint tissue in the form of monosodium urate crystals
Gout most frequently happens at what joint?
first metatarsal
Gout of the foot is called:
podagra
How to differentiate between gout and cellulitis?
Gout is very painful and doesn’t have an origin
When does congestive heart failure occur?
when the heart is not able to pump blood adequately and perfuse all tissues sufficiently
Natriuretic peptides generally function to inhibit the:
reabsorption of sodium in the renal tubule so that sodium excretion into the urine is increased
The three major natriuretic peptides are:
ANP, BNP, C-type Natriuretic peptide (CNP)
ANP is synthesized in:
atrial cardiomyocytes
BNP primarily released from
ventricles of the heart
C-type natriuretic peptide (CNP) is found in?
the nervous system and endothelium
ANP and BNP are released when?
the atria and ventricles stretch
ANP and BNP cause:
vasorelaxation and increase the amount of sodium and water excreted
What’s the indication for BNP?
to aid in diagnosis of congestive heart failure
BNP level has a strong correlation with:
left ventricular pressures
BNP can be used in the diagnosis of congestive heart failure with an accuracy of
83%
What # for BNP basically rules in CHF
500
Increased BNP:
congestive heart failure, MI, hypertension, cor pulmonale (right-sided heart failure)
When does an MI occur?
when one of the coronary arteries suffers critical blockage
where is creatine found?
mitochondria and cytoplasm of skeletal muscle
What is metabolized to generate more ATP?
creatine
Without the Creatine -> phosphocreatine + ADP reaction ATP stores would be depleted within?
10 seconds
Creatine goes to Phosphocreatine via
CK enzyme
Where is CK enzyme found?
cardiac, skeletal muscle, brain = high energy tissues
Creatine kinase exists in three different isoenzymes:
CK-MM, CK-BB, CK-MB
CK-MM is found in:
skeletal muscle
CK-BB is found in:
brain
CK-MB is found in:
predominately found in heart and is specific for cardiac cells, small amounts in skeletal muscles
What is the largest CK type?
CK-MM (94-99%)
Creatine kinase is elevated in:
disorders/injury to muscle (usually skeletal) or neurologic disease
What body type is associated with higher levels of CK?
people with larger muscle mass
Increased total creatine kinase:
strenuous exercise, recent surgery, rhabdomyolysis, myositis, recent convulsions, trauma/crush injuries, neuromuscular disorder, statin use/medications for cholesterol, excessive exercise
CK-MB tests specifically for injury to the
myocardium
CK-MB rises about x hours after MI
3-6 hours
CK-MB is not elevated in all patients until
12 hours after MI
CK-MB returns to baseline following MI in
36-48 hours
Why might CK not be the best for detecting MI?
If you are having an MI, you might not know for 12 hours. Also, it can be released from skeletal muscles (maybe falsely elevated in pt with muscle disorder/injury)
Is CK-MB the preferred test to diagnose myocardial infarction?
No
Increased CK-MB:
acute myocardial infarction, cardiac ischemia, myocarditis, ventricular arrhythmias
Troponins are proteins that control the interaction of
actin and myosin in skeletal and cardiac muscle
What do troponins interact with during muscle contraction:
calcium ions and tropomyosin
When troponin is bound by calcium it allows exposure of:
the myosin binding sites on actin
What are the three subtypes of troponin:
I, T, and C
Troponin C contains the:
calcium binding site
Troponin I inhibits:
the interaction of actin and myosin
Troponin T binds:
troponin and tropomyosin
What is the cardiac specific subtype for troponin I?
cTnI
What is the cardiac specific subtype for troponin T?
CTnT
What troponin subtypes are useful in diagnosing an MI?
Troponin I and Tropinin T
How much troponin will a healthy individual have in their blood?
little to none
Troponin levels rise x hours after onset of MI
2-3 hours
Troponin levels stay elevated for x days after MI
7-14 days
Is cardiac troponin I or T used more frequently to diagnose MI? Why?
Cardiac Troponin I, because renal failure more frequently increases Cardiac Troponin T
Elevated troponin:
unstable angina, MI, congestive heart failure, myocarditis, severe PE, CPR, cardioversion or pacemaker firings
Myoglobin only occurs in:
skeletal or cardiac muscle tissue
Myglobin serves as:
short-term oxygen storage in muscle tissue
Myoglobin is only released into serum when there is a :
skeletal or cardiac muscle injury
Myoglobin increases in x hours after cardiac injury
3 hours
Myglobin is more sensitive but not as specific for MI than:
CK-MB
Elevated myglobin:
MI, myositis, skeletal muscle injury, seizures, muscular dystrophy, recent cocaine use, trauma/inflammation
What is left behind when a clot is dissolved?
fibrin degradation products (FDPs)
When is D-dimer formed?
during lysis of cross-linked fibrin through the action of plasmin
D-dimer is used to identify when a patient has:
intravascular clotting
D-dimer is used to diagnose a patient with a:
DVT or PE
Describe the sensitivity/specificity of D-dimer test
Highly sensitive, but not specific enough
Does D-dimer test have a better positive or negative predictive value?
Better negative value
D-dimer elevations:
DVT, PE, disseminated intravascular coagulation (DIC), sickle cell anemia, surgery, pregnancy, elderly patients
What is the leading cause of mortality worldwide?
Coronary heart disease
CHD causes what percent of deaths worldwide?
50%
There’s a linear relationship between CHD and?
hyperlipidemia
Cholesterol is derived primarily from:
diet of animal origin
Cholesterol is metabolized in:
liver
Cholesterol is carried on:
lipoproteins
What carries 75% of cholesterol?
Low-density lipoprotein
What carries 25% of cholesterol?
High-density lipoprotein
If the initial lipid panel is normal, test every?
5 years
If the initial lipid panel is borderline, test every?
3 years
In patients over age 65 who have had more than 1 normal screening in past, it is reasonable to:
stop screening
Generally, lipid panel should be measured when:
fasting
How long should fasting occur?
12-14 hours prior to test is ideal
What is ok to ingest when fasting?
water and black coffee
Total cholesterol includes:
LDL + HDL + VLDL
Variation in total cholesterol form one test to the next can be:
15%
Total cholesterol can vary due to:
stress, minor illness, positional changes when drawing blood
Triglycerides are produced in:
the liver
Triglycerides are composed of
chain of fatty acids + glycerol
Triglycerides are supplied in diet and make up about x% of caloric intake
35-40%
Muscles prefer what as their energy source?
fatty acids
If blood levels of triglycerides are high, triglycerides are deposited into:
fatty tissues
Normal triglyceride levels:
less than 150 mg/dL
Borderline high triglyceride levels:
150-199 mg/dL
High triglyceride levels:
200-499 mg/dL
Very high triglyceride levels:
500 mg/dL or above
Factors that alter triglycerides: increase
familial hypertriglyceridemia, hyperlipidemia, high carbohydrate diet, poorly controlled diabetes
Factors that alter trigylcerides: decrease
malabsorption/malnutrition, thyroid disease
Which is the “good cholesterol”?
High-density lipoprotein (HDL)
The function of HDL is to transport:
cholesterol from tissues of the body and the vascular endothelium returning it to the liver
What is an inverse risk factor for CHD?
HDL
Acceptable HDL level for men?
> 40 mg/dL
Desired HDL level for men?
> 60 mg/dL
Acceptable HDL for women?
> 50 mg/dL
Desired HDL for women?
> 60 mg/dL
HDL increases:
genetics, exercise, moderate alcohol use, healthier eating choices, estrogen administration
HDL decreases:
metabolic syndrome, genetics, tobacco use
Which is the “bad cholesterol”
Low-density lipoprotein (LD)
LDL is deposited?
in the walls of arteries
LDL is most commonly calculated by:
Friedewald formula
Friedewald formula:
LDL = total cholesterol - (HDL + 1/5 Tg)
Friedeweld is only valid if triglyceride level is:
<400 mg/dL
LDL levels ideal for those at risk of heart disease
70-100 mg/dL
LDL levels near ideal
100-130 mg/dL
LDL levels borderline
130-159 mg/dL
LDL levels high
> 160 mg/dL
Factors that impact LDL: Increase
Genetics, high staturated fat in diet, excessive alcohol consumption, chronic liver disease, hypothyroidism
Factors that impact LDL: decrease
genetics, exercise, low fat diet, hyperthyroidism
What is used to test LDL particles?
Gel electrophoresis
LDL particle types:
Pattern A and Pattern B and Pattern I
Pattern A (LDL)
large particle size
Pattern B (LDL)
small, dense particle size
What is the issue with pattern B?
higher ability to enter walls of blood vessel and increased risk of CHD
Pattern I:
Intermediate particle size
Small, dense LDL particles is associated with:
increased risk of CAD, promotion of atherosclerosis and thrombosis
Small LDL particles result in increased (three things)
-half-life in the circulation due to decreased receptor binding -oxidative stresses -penetrance of arterial walls
What are some LDL particle size testing?
Spectracell and LipoScience NMR Lipoprofile test
What’s the issue (patient side) with particle size test?
Very costly test (167 and up) and insurance not always covered
