[Is body surface area (BSA) suitable for indexing renal and dialysis clearances and other physiological parameters? A theoretical approach and a critical analysis (Part 2)]

Abstract

Many parameters of biological functions, interesting different branches of medicine, have to be indexed by the same value for each other comparison between single individuals or between-within groups.Body Surface Area (BSA) and 1.73 m2 reference value are probably the most used tools for indexation, but a growing number of scientific papers emphasize the risk of under or over estimates of data by BSA indexation in overweight-obese or on the contrary underweight individuals. This study has been planned to evaluate such a problem: a) by a theoretical approach, indexing to 1.73 m2 the creatinine clearance(CtCl) in an ideal population, and b) analysing and debating the doubts and problems about the indexation by BSA in many fields, the possibilities of indexation by other methods, or to use BSA with different approach, to reduce the risk of bias, evaluating the possibility of this target in a real population of 45 men and 84 women undergoing Peritoneal Dialysis (PD) - II - The feasibility to agree to an identical value of normal or abnormal renal function for every age or, on the contrary, to have a normal range for each age, are analysed and discussed.About BSA as indexing tool, it is pointed out: a) the lack of significative correlation between BSA and GFR and other parameters b) the increasing gap during years between 1.73 m2 BSA and the average BSA.