Biochemical measurements of renal disease Flashcards
creatinine is formed
large muscle mass because produced by muscles
limitations of creatinine
it is not secreted into the renal tubule - <10% of creatinine. small amount of secretion.
the ideal marker of GFR would be?
Appear at a constant rate
Be freely filtered at the glomerulus
Not be reabsorbed from the renal tubule
Not be secreted by the renal tubule
Not undergo extra-renal elimination - should not be eliminated in any other way
inulin
plant carbohydrate
limitations of inulin?
not endogenous - must be injected to measure the end product or easy to measure - must take multiple measurements, can’t use in clinical practice
benefits of inulin as a marker?
appears at a constant rate, freely filtered at the glomerulus, not reabsorbed from the renal tubule, not secreted into the renal tubule, doesn’t undergo extra-renal elimination
limitations of urea?
does not appear at a constant rate, is not reabsorbed form the renal tubule and undergo extra-renal elimination
what is the main way of testing for GFR?
creatinine levels
serum creatinine cofounders?
age - younger and male - large muscle mass
sex
muscle mass. - increased load of creatinine level because of larger muscle mass
how to get around cofounders of creatinine?
use of proxies
what is clearance?
it represents the volume of plasma that is theoretically cleared of a substance per minute
who is categorized of CKD1?
> =90
