Carbohydrates, Lipids, and Proteinscontinued Clinical Chemistry Review 82
ANALYTE REFERENCE RANGE CLINICAL SIGNIFICANCE OTHER
Total protein
Albumin
Microalbumin
(on urine)
6.4–8.3 g/dL
3.5–5 g/dL
50–200 mg/24 hr
predictive of diabetic
nephropathy
↑dehydration, chronic inflamma-
tion, multiple myeloma
↓nephrotic syndrome, malab-
sorption, overhydration, hepatic
insufficiency, malnutrition,
agammaglobulinemia
↑dehydration
↓malnutrition, liver disease,
nephrotic syndrome, chronic
inflammation
↑in diabetics at risk of
nephropathy
<4.5 g/dL associated with peripheral edema.
Biuret method. Alkaline copper reagent reacts
with peptide bonds.
Largest fraction of plasma proteins. Synthesized
by liver. Regulates osmotic pressure. Measure by
dye binding, e.g., bromocresol green (BCG),
bromocresol purple (BCP).
Detects albumin in urine earlier than dipstick
protein. Strict control of glucose & blood
pressure can prevent progression to end-stage
renal disease. Immunoassays on 24-hr urine.
Alternative is albumin-to-creatinine ratio on
random sample. 30–300 mg albumin/g
creatinine = microalbuminuria. Urine
dipsticks available for albumin & albumin-to
creatinine ratio.
