glomerular filtration rate estimation based on cystatin c formulas among neonates

Background: glomerular filtration rate (gfr) is the best indicator to assess renal function; however, it is difficult to perform it, especially in neonates. serum creatinine is the most commonly used marker of gfr; nevertheless, it has some limitations since it can be affected by factors other than renal function. cystatin c, another endogenous marker used to estimate gfr, is not affected by non-renal factors. the results of some studies suggest that serum cystatin c levels are more accurate tests of kidney function than serum creatinine levels. this study aimed to estimate gfr with cystatin c-based formulas among neonates and determine the correlations between these methods and the schwartz formula. methods: the population of this research consisted of 99 neonates whose serum creatinine and cystatin c levels were measured concurrently. moreover, the glomerular filtration rate was estimated using the schwartz formula and 14 cystatin c-based formulas separately. results: based on the findings, all gfr values based on cystatin c formulas correlated significantly with each other (p<0.05); however, with one exception, none of these values correlated with schwartz gfr (p>0.05). the only cystatin c formula that yielded values correlating with the schwartz formula was cyscreq, which used serum cystatin c and creatinine concomitantly. conclusion: it can be concluded that since all gfr values based on cystatin c correlated significantly and cystatin cwasindependent of non-renal factors, cystatin c reflected the real gfr more accurately than serum creatinine. nonetheless, further studies with gold standard techniques are required to verify the usefulness of cystatin c-based formulas.