Carbohydrates Flashcards
How are monosacchrides formed?
from the cleavage of larger sugars.
how does glucose enter the cell?
via insulin, from there it is metabolized to ATP
define glycogenolysis
conversion of glycogen (from the liver) to glucose (g-6-p) and can occur within minutes.
what is gluconeogensis?
it is the transformation from non-carbohydrate sources (amino acids, lactate, and glycerol) to the formation of glucose. it takes HOURS.
How do glucagon and insulin work with each other?
They work in opposition of each other. insulin stimulates sugar uptake from blood. glucagon stimulates the production of glucose via glycogenolysis and gluconeogenesis. this is minute to minute regulation.
what other hormones act to increase liver glucose production?
epinephrine, growth hormone, cortisol, thyroxine, and somatostatin.
when should glucose (ideally) be obtained?
after and 8-10 hour over night fast.
What are the normal values for glucose?
fasting : 70-99
random plasma: less than 200
2 hour post meal: less than 140
critical values: less than 45 more than 450
what is the renal threshold?
When the blood level starts to exceed 160-180, then sugar will start to spill into the urine.
how is csf related to plasma glucose?
its approximately 60% of plasma glucose. and therefore should always be evaluated in relation to plasma glucose. plasma glucose > csf glucose.
bacterial = less than normal glucose, viral= normal
Define hypoglycemia:
when blood sugar falls below 50.
what gets used as the energy source when prolonged fasting occurs?
ketones
what is the brain totally dependent on for energy production?
glucose
what are some of the symptoms of someone who is hypoglycemic?
increased hunger, sweating, confusion, nausea and vomitting, slurring speech
what are the lab findings for hypoglycemia?
decreased blood glucose, increased insulin (if insulinoma)
What is Type I diabetes?
results from cell-mediated autoimmune destruction of the B-cells of the pancreas; linked to genetic susceptibility and environmental factors, rate of cellular destruction is variable. completely dependent on insulin. most severe, ketosis-prone
What is type II diabetes?
caused by insulin secretion that is delayed or insufficient for the glucose load, or perish tissue insulin resistance. insulin levels will appear normal in early course, but then become deficient.
What are the symptoms of diabetes?
polydypsia, polyuria, polyphagia
what are the diagnostic criteria for diabetes?
- symptoms (3 p’s) and a random 200mg/dL blood sugar. 2. fasting blood sugar greater than 126 3. HgbA1c value greater than 6.5 4. PP >200 blood sugar during OGTT
What is an oral glucose tolerance test?
- draw a sample 2. administer glucose 3. draw blood sugar at 30, 60, 120, 180 min
What is keto-acid metabolism?
In type I diabetes mellitus, lack of insulin causes cells to mobilize FFA’s from triglycerides. Fatty Acid degradation becomes the main source of energy for the cell. this can cause lower blood pH and cause metabolic acidosis.
What are three ketones?
acetoacetate, B-hydroxybuterate (current tests can’t identify this ketone), acetone
What are the symptoms of ketoacidosis?
increased plasma, urine glucose. increased ketones in plasma and urine, decreased pH and bicarb, increased anion gap, increased potassium,
T/F: Fasting plasma glucose only reflects acute changes
true
What is glycosated hemoglobin?
Hgb A1c is occurs due to the non-enzymatic addition of glucose residue to terminal amino groups. It assesses diabetic control of the last 2-3 months. patient does not have to fast for this
What are the normal ranges for HgbA1C?
non-diabetic is less than 4%
greater than 6.5% indicates diabetes.
GOAL FOR DIABETICS: 6-7%
one can roughly estimate the plasma glucose
If patients need more accurate monitoring, you can measure..
glycosylated albumin, and can be measured over a period of 2-3 weeks.
What is UAE?
Urinary albumin excretion. An increased UAE indicates that there may be some microvascular damage, and is highly predictive of diabetic neuropathy, end stage renal disease, and retinopathy.
UAE can be effected by…
exertion, posture, fluid intake, acute surgery, etc
who should perform self monitoring of blood glucose?
all patients with diabetes!!
What are some of the variables that can affect glucose readings?
Fase decreases: polycythemia, dehydration
false increases: heamtocrit
What is GDM associated with?
neonatal mortality, and the mothers are at an increased risk of developing DM down the road.
what is a glycogen storage disorder?
It is a disorder in one of the 8 enzymes that break down glycogen leading to a buildup of glycogen. severe hypoglycemia can occur because glycogen cannot be converted back to glucose.
What is the most common form of glycogen storage disorder?
TYPE I (von gierke’s disease). patient will have a massive liver due to accumulation of glycogen. may also see growth retardation.
What are disorders of galactose metabolism?
genetic disorder resulting format he lack of enzyme needed to metabolize galactose to glucose resulting in galactose in the plasma.
What are the symptoms of galactose metabolism?
after milk ingestion: vomit, diarrhea, FTT, liver disease cataracts. most common defiency is GALACTOSE-1-PHOSPHATE-URIDYL TRANSFERASE.
