False estimates of elevated creatinine.

One of the most common reasons for a nephrology consult is an elevated creatinine. An elevation in the serum creatinine concentration usually reflects a reduction in the glomerular filtration rate (GFR). Given the association of elevated creatinine and risk of cardiovascular mortality, it is important to keep in mind that at times the elevation of the creatinine is not representative of a true reduction in GFR. There are various causes of factitious elevation of creatinine. They can be broadly grouped into increased production of creatinine, interference with the assay and decreased tubular secretion of creatinine.