Biomarkers

Target: Creatinine

Creatinine, or creatine anhydride, is a breakdown product of creatine phosphate in muscle. The loss of a water molecule from creatine results in the formation of creatinine. Creatinine is transferred to the kidneys by blood plasma, whereupon it is eliminated from the body by glomerular filtration and partial tubular excretion. Creatinine is usually produced at a fairly constant rate by the body. Measuring serum creatinine is a simple test and it is the most commonly used indicator of renal function. A rise in blood creatinine levels is observed only with marked damage to functioning nephrons. Therefore, this test is not suitable for detecting early kidney disease. The typical reference range for women is considered about 45-90 µmol/L; for men 60-110 µmol/L. Creatine and creatinine are metabolized in the kidneys, muscle, liver, and pancreas. Creatinine is associated with chronic renal failure and kidney disease where adults (>18 years old) have a significantly elevated level of creatinine in the blood at a concentration of 440.7 +/- 44.2 μM (PMID: 7296840) compared to normal adults at a concentration of 82.6 +/- 26.2 μM (PMID: 7296840). Creatinine is also associated with Brown Vialetto Van Laere Syndrome, a rare neurological disorder characterised by progressive pontobulbar palsy associated with sensorineural deafness where newborns (0-30 days old) with this syndrome have a significantly elevated level of creatinine in the blood at 175.923 μM (PMID: 18310267) compared to normal newborns at a concentration of 17.681-39.782 μM (PMID: 18310267). Creatinine has also shown to be associated with uremia and 21 hydroxylase deficiency. In adults (>18 years old) with uremia, creatinine is significantly elevated at a concentration of 1203.540 +/- 407.0796 μM (PMID: 12675874) compared to normal adults at a concentration of <106.195 μM (PMID: 12675874). Similarly, in adults (>18 years old) with 21 hydroxylase deficiency, creatinine is significantly elevated in the blood at a concentration of 203.328 μM (PMID: 11038205) compared to normal adults at a concentration of 35-122 μM (PMID: 15651030).