TY - JOUR
T1 - Differential Estimation of CKD Using Creatinine- Versus Cystatin C-Based Estimating Equations by Category of Body Mass Index
AU - Vupputuri, Suma
AU - Fox, Caroline S.
AU - Coresh, Josef
AU - Woodward, Mark
AU - Muntner, Paul
N1 - Funding Information:
Support: Dr Coresh was supported by the Chronic Kidney Disease Epidemiology (CKD-EPI) Collaboration funded by grants UO1 DK 053869, UO1 DK 067651, and UO1 DK 35073. CKD-EPI funded the cystatin C assays.
PY - 2009/6
Y1 - 2009/6
N2 - Backgound: Adiposity is associated with cystatin C. Cystatin C-based glomerular filtration rate (GFR) equations may result in overestimation of chronic kidney disease (CKD) prevalence at greater body mass index (BMI) levels. Study Design: Cross-sectional. Setting & Participants: 6,709 US adult Third National Health and Nutrition Examination Survey participants. Factor: BMI. Outcome: Absolute percentage of difference in prevalence of stage 3 or 4 CKD between creatinine- and cystatin C-based estimating equations by level of BMI. Measurements: Normal weight, overweight, and obesity were defined as BMI of 18.5 to less than 25.0, 25 to less than 30.0, and 30 kg/m2 or greater, respectively. Stage 3 or 4 CKD (estimated glomerular filtration rate [eGFR], 15 to 59 mL/min/1.73 m2) was defined using the 4-variable creatinine-based Modification of Diet in Renal Disease Study equation (eGFRMDRD); cystatin C level, age, sex, and race equation (eGFRCysC,age,sex,race); cystatin C-only equation (eGFRCysC); cystatin C level of 1.12 mg/L or greater (increased cystatin C); and an equation incorporating serum creatinine level, cystatin C level, age, sex, and race (eGFRCr,CysC,age,sex,race). Results: Differences in stage 3 or 4 CKD prevalence estimates between eGFRCysC,age,sex,race, eGFRCysC, and increased cystatin C, separately, and eGFRMDRD were greater at higher BMI levels. Specifically, compared with estimates derived using eGFRMDRD for normal-weight, overweight, and obese participants, estimated prevalences of stage 3 or 4 CKD were 2.1%, 3.0%, and 6.5% greater when estimated by using eGFRCysC,age,sex,race (P trend = 0.005); 0.1%, 0.6%, and 2.2% greater for eGFRCysC (P trend = 0.03); 2.9%, 5.2%, and 9.5% greater for increased cystatin C (P trend < 0.001); and -0.1%, -0.4%, and 0.0% greater for eGFRCr,CysC,age,sex,race, respectively (P trend = 0.7). Limitations: No gold-standard measure of GFR was available. Conclusions: BMI may influence the estimated prevalence of stage 3 or 4 CKD when cystatin C-based equations are used.
AB - Backgound: Adiposity is associated with cystatin C. Cystatin C-based glomerular filtration rate (GFR) equations may result in overestimation of chronic kidney disease (CKD) prevalence at greater body mass index (BMI) levels. Study Design: Cross-sectional. Setting & Participants: 6,709 US adult Third National Health and Nutrition Examination Survey participants. Factor: BMI. Outcome: Absolute percentage of difference in prevalence of stage 3 or 4 CKD between creatinine- and cystatin C-based estimating equations by level of BMI. Measurements: Normal weight, overweight, and obesity were defined as BMI of 18.5 to less than 25.0, 25 to less than 30.0, and 30 kg/m2 or greater, respectively. Stage 3 or 4 CKD (estimated glomerular filtration rate [eGFR], 15 to 59 mL/min/1.73 m2) was defined using the 4-variable creatinine-based Modification of Diet in Renal Disease Study equation (eGFRMDRD); cystatin C level, age, sex, and race equation (eGFRCysC,age,sex,race); cystatin C-only equation (eGFRCysC); cystatin C level of 1.12 mg/L or greater (increased cystatin C); and an equation incorporating serum creatinine level, cystatin C level, age, sex, and race (eGFRCr,CysC,age,sex,race). Results: Differences in stage 3 or 4 CKD prevalence estimates between eGFRCysC,age,sex,race, eGFRCysC, and increased cystatin C, separately, and eGFRMDRD were greater at higher BMI levels. Specifically, compared with estimates derived using eGFRMDRD for normal-weight, overweight, and obese participants, estimated prevalences of stage 3 or 4 CKD were 2.1%, 3.0%, and 6.5% greater when estimated by using eGFRCysC,age,sex,race (P trend = 0.005); 0.1%, 0.6%, and 2.2% greater for eGFRCysC (P trend = 0.03); 2.9%, 5.2%, and 9.5% greater for increased cystatin C (P trend < 0.001); and -0.1%, -0.4%, and 0.0% greater for eGFRCr,CysC,age,sex,race, respectively (P trend = 0.7). Limitations: No gold-standard measure of GFR was available. Conclusions: BMI may influence the estimated prevalence of stage 3 or 4 CKD when cystatin C-based equations are used.
KW - Chronic kidney insufficiency
KW - body mass index
KW - creatinine
KW - cystatin C
KW - glomerular filtration rate
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U2 - 10.1053/j.ajkd.2008.12.043
DO - 10.1053/j.ajkd.2008.12.043
M3 - Article
C2 - 19394726
AN - SCOPUS:67349114859
SN - 0272-6386
VL - 53
SP - 993
EP - 1001
JO - American Journal of Kidney Diseases
JF - American Journal of Kidney Diseases
IS - 6
ER -