Hemoglobin A1C, Insulin, C-peptide, Amylase, Lipase, Uric Acid

Question 1

Hemoglobin A1C indications

Answer 1

diagnose diabetes, monitor for acceptable control of diabetes, monitor for risk of diabetes-related complications

Question 2

hemoglobin A1C

Answer 2

readily binds w/ glucose via glycosylation; diagnosis >6.5% of total hgb; goal in diabetic is less than 7%; used to determine a pt’s glucose over a 3-4 mo. period

Question 3

calculate mean plasma glucose

Answer 3

(35.6 x HgbA1C) - 77.3

Question 4

insulin level

Answer 4

insulin’s release facilitates the movement of glucose from circulatory system to the cell. the test can be used to detect an insulinoma or find the cause of hypoglycemia. not used in dx or tx of DM.

Question 5

insulin level increased in:

Answer 5

insulinoma, obesity, fructose or galactose intolerance, Cushing syndrome, acromegaly, early type 2 DM

Question 6

insulin level decreased in:

Answer 6

IDDM (typically type-1), hypoputuitarism, chronic pancreatitis or pancreatectomy

Question 7

C-peptide

Answer 7

connecting peptide. connects alpha and beta chains of proinsulin (precursor of insulin); chains separate in beta cells of pancreas

Question 8

C-peptide test

Answer 8

levels correlate well to levels of insulin; test is useful to ascertain functioning of the pt’s pancreas and ability to produce insulin; can be used to determine hypoglycemia

Question 9

c-peptide level in type-1 diabetes

Answer 9

low

Question 10

c-peptide level in type-2 diabetes

Answer 10

normal or high

Question 11

amylase

Answer 11

an enzyme secreted from ainar cells of pancreas; involved in catabolism of carbs. damage to acinar cells causes excess amylase in serum. excreted via kidneys rapidly (nl level w/in 12 hrs onset)

Question 12

amylase test

Answer 12

used to evaluate abd. pain/detect pancreatitis. normal: 27-130 U/L

Question 13

amylase increased in:

Answer 13

acute or chronic pancreatitis, pancreatic cancer, obstruction by gallstone, renal failure (decreased clearance), ectopic preg, mumps, cholecystitis

Question 14

lipase

Answer 14

secreted by pancreas into duodenum; involved in catabolism of triglycerides into fatty acids. damage to acinar cells of pancrease causes excess lipase in circulation. excreted via kidneys. stays in blood longer than amylase

Question 15

lipase test

Answer 15

used to evaluate abd. pain/detect pancreatitis. fairly specific for pancreatic injury. normal: 0-160 U/L.

Question 16

uric acid

Answer 16

end byproduct of purine nucleotide catabolism

Question 17

uric acid level

Answer 17

normal level: 4.0-8.5 mg/dL. at >6.8 uric acid can be deposited into joint tissue in form of monosodium urate crystals

Question 18

uric acid level elevated in:

Answer 18

gout (hyperuricemia), high purine diets (animal proteins), alcohol abuse (increased production), cancer (increased purine metabolism), renal failure, dehydration by diuretics