Clinical Significance

   It is useful for Normalization of urinary analytes to account for the variation in urinary concentrations between individuals when using random urine collections

Specimen

   Serum

Stability

   Refrigerated (preferred) : 30 days

   Frozen : 30 days

   Ambient : 30 days

Reference Range

   Male : 0.67 – 1.17 mg/dL

   Female : 0.51 – 0.95 mg/dL

Interpretation

   Decreased creatinine clearance indicates decreased glomerular filtration rate. This can be due to conditions such as progressive renal disease, or result from adverse effect on renal hemodynamics that are often reversible including certain drugs or from decreases in effective renal perfusion (eg, volume depletion or heart failure).

   Increased creatinine clearance is often referred to as "hyperfiltration" and is most commonly seen during pregnancy or in patients with diabetes mellitus, before diabetic nephropathy has occurred. It also may occur with large dietary protein intake.

Limitation

   Intra-individual variability in creatinine excretion may be due to differences in muscle mass or amount of ingested meat. Acute changes in glomerular filtration rate, before a steady state has developed, will alter the amount of urinary creatinine excreted.