[Assessing renal function in elderly people].

Accurate renal function measurement is important for identification of chronic renal disease which may allow early implementation of renoprotective therapy and proper medication dosing among elderly individuals. This paper proposed to review available data about the strengths and weaknesses of current methods of measuring and estimating of renal function and to appoint which of them is the best in older people. Serum creatinine and creatinine clearance are inaccurate screening tests for renal failure in elderly subjects leading to under-recognition and/or underestimation of the degree of renal failure due to the reduced muscle mass and the inappropriate collection of a timed urine sample (urinary incontinence, cognitive impairment). For all their limitations, formulaic estimates of glomerular filtration rate can provide better information in this population. Further researches must be focused on development of a more precise estimation equation and on implementation in clinical practice of a novel marker of renal function, serum cystatin C, claimed to be superior to plasma creatinine in the elderly individuals.