Existing creatinine-based equations overestimate glomerular filtration rate in Indians

BMC Nephrology

Nancy Sahni¹  Seiichi Matsuo²  Yoshinari Yasuda²  Harbir Singh Kohli³  Vivekanand Jha³  Krishan L. Gupta³  Vinod Kumar³  Vivek Kumar³  Ashok Kumar Yadav³  Masaru Horio⁴ 

[1] Department of Dietitics, Postgraduate Institute of Medical Education and Research;Department of Nephrology, Nagoya University Graduate School of Medicine;Department of Nephrology, Postgraduate Institute of Medical Education and Research;Division of Health Sciences, Graduate School of Medicine, Osaka University;

关键词: Glomerular filtration rate;    Chronic kidney disease;    Creatinine;    Cystatin C;    Inulin clearance;   

DOI  :  10.1186/s12882-018-0813-9

来源: DOAJ

【 摘 要 】

Abstract Background Accurate estimation of glomerular filtration rate (GFR) is important for diagnosis and risk stratification in chronic kidney disease and for selection of living donors. Ethnic differences have required correction factors in the originally developed creatinine-based GFR estimation equations for populations around the world. Existing equations have not been validated in the vegetarian Indian population. We examined the performance of creatinine and cystatin-based GFR estimating equations in Indians. Methods GFR was measured by urinary clearance of inulin. Serum creatinine was measured using IDMS-traceable Jaffe’s and enzymatic assays, and cystatin C by colloidal gold immunoassay. Dietary protein intake was calculated by measuring urinary nitrogen appearance. Bias, precision and accuracy were calculated for the eGFR equations. Results A total of 130 participants (63 healthy kidney donors and 67 with CKD) were studied. About 50% were vegetarians, and the remainder ate meat 3.8 times every month. The average creatinine excretion were 14.7 mg/kg/day (95% CI: 13.5 to 15.9 mg/kg/day) and 12.4 mg/kg/day (95% CI: 11.2 to 13.6 mg/kg/day) in males and females, respectively. The average daily protein intake was 46.1 g/day (95% CI: 43.2 to 48.8 g/day). The mean mGFR in the study population was 51.66 ± 31.68 ml/min/1.73m2. All creatinine-based eGFR equations overestimated GFR (p < 0.01 for each creatinine based eGFR equation). However, eGFR by CKD-EPICys was not significantly different from mGFR (p = 0.38). The CKD-EPICys exhibited lowest bias [mean bias: −3.53 ± 14.70 ml/min/1.73m2 (95% CI: -0.608 to −0.98)] and highest accuracy (P30: 74.6%). The GFR in the healthy population was 79.44 ± 20.19 (range: 41.90–134.50) ml/min/1.73m2. Conclusion Existing creatinine-based GFR estimating equations overestimate GFR in Indians. An appropriately powered study is needed to develop either a correction factor or a new equation for accurate assessment of kidney function in the Indian population.

【 授权许可】

Unknown