The Inverse of Serum Creatinine Multiplied by 100 (1/CtS100): The Key to Calculate the Actual Creatinine Clearance and Actual Excreted Creatinine in Renal Failure

Giancarlo Ruggieri

In a previous paper it was shown that the inverse of serum creatinine multiplied by 100 very closely correlated with the estimates of the glomerular filtration rate (GFR) by MDRD simplified formula. In past few years and more recently, the inverse of serum creatinine was correlated with GFR values measured by high precision methods. On this basis it was assumed to verify which of the variables measured creatinine clearance and excretion, and creatinine clearance and excretion estimated on the basis of 1/CtS100 and 1/CtS would better correlate with MDRD GFR, CtS, BMI, Protidemia, Serum Urea, .body cellular mass, fat mass, and extracellular water, variables all rationally expected to be somehow linked to the variables above. The variables based on 1/CtS100 had the best correlations, consequently, this method was proposed to measure the actual creatinine clearance and the actual excreted creatinine in the case of substitutive treatment by dialysis and most likely also in the case of decreased renal function.