Dataset Information

Estimated glomerular filtration rate is a poor predictor of the concentration of middle molecular weight uremic solutes in chronic kidney disease.

ABSTRACT:

Background

Uremic solute concentration increases as Glomerular Filtration Rate (GFR) declines. Weak associations were demonstrated between estimated GFR (eGFR) and the concentrations of several small water-soluble and protein-bound uremic solutes (MW<500 Da). Since also middle molecular weight proteins have been associated with mortality and cardiovascular damage in Chronic Kidney Disease (CKD), we investigated the association between several eGFR formulae and the concentration of Low Molecular Weight Proteins (LMWP) (MW>500 Da).

Materials and methods

In 95 CKD-patients (CKD-stage 2-5 not on dialysis), associations between different eGFR-formulae (creatinine, Cystatin C-based or both) and the natural logarithm of the concentration of several LMWP's were analyzed: i.e. parathyroid hormone (PTH), Cystatin C (CystC), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-?), leptin, retinol binding protein (RbP), immunoglobin light chains kappa and lambda (Ig-? and Ig-?), beta-2-microglobulin (?(2)M), myoglobin and fibroblast growth factor-23 (FGF-23)).

Results

The regression coefficients (R(2)) between eGFR, based on the CKD-EPI-Crea-CystC-formula as reference, and the examined LMWP's could be divided into three groups. Most of the LMWP's associated weakly (R(2) <0.2) (FGF-23, leptin, IL-6, TNF-?, Ig-?, Ig-?) or intermediately (R(2) 0.2-0.7) (RbP, myoglobin, PTH). Only ?(2)M and CystC showed a strong association (R(2) >0.7). Almost identical R(2)-values were found per LMWP for all eGFR-formulae, with exception of CystC and ?(2)M which showed weaker associations with creatinine-based than with CystC-based eGFR.

Conclusion

The association between eGFR and the concentration of several LMWP's is inconsistent, with in general low R(2)-values. Thus, the use of eGFR to evaluate kidney function does not reflect the concentration of several LMWP's with proven toxic impact in CKD.

SUBMITTER: Neirynck N

PROVIDER: S-EPMC3432070 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature

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Publications

Estimated glomerular filtration rate is a poor predictor of the concentration of middle molecular weight uremic solutes in chronic kidney disease.

Neirynck Nathalie N Eloot Sunny S Glorieux Griet G Barreto Daniela V DV Barreto Fellype C FC Liabeuf Sophie S Lenglet Aurélie A Lemke Horst D HD Massy Ziad A ZA Vanholder Raymond R

PloS one 20120831 8

<h4>Background</h4>Uremic solute concentration increases as Glomerular Filtration Rate (GFR) declines. Weak associations were demonstrated between estimated GFR (eGFR) and the concentrations of several small water-soluble and protein-bound uremic solutes (MW<500 Da). Since also middle molecular weight proteins have been associated with mortality and cardiovascular damage in Chronic Kidney Disease (CKD), we investigated the association between several eGFR formulae and the concentration of Low Mo ...[more]

PMID: 22952928

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Project description:Background and objectivesMarijuana use has become more widely accepted in the United States and has been legalized in many areas. Although it is biologically plausible that marijuana could affect kidney function, epidemiologic data are lacking.Design, setting, participants, & measurementsWe conducted a cohort study among young adults with preserved eGFR (i.e., eGFR?60 ml/min per 1.73 m2) using data from the Coronary Artery Risk Development in Young Adults (CARDIA) study. At scheduled examinations occurring every 5 years and starting at study year 10 (calendar years, 1995-1996), cystatin C was collected over a 10-year period, and urine albumin-to-creatinine ratio was collected over a 15-year period. We investigated the cross-sectional association between current and cumulative marijuana use (in marijuana-years; one marijuana-year equals 365 days of marijuana use) and eGFR by cystatin C (eGFRcys) at year 10. In longitudinal analyses, we investigated the association between cumulative marijuana use and eGFRcys change and rapid (?3%/year) eGFRcys decline over two 5-year intervals and prevalent albuminuria (urine albumin-to-creatinine ratio ?30 mg/g) over a 15-year period.ResultsPast or current marijuana use was reported by 83% (3131 of 3765) of the cohort, and the mean eGFRcys was 111 ml/min per 1.73 m2 at year 10. Over the following 10 years, 504 had rapid eGFRcys decline, and over the following 15 years, 426 had prevalent albuminuria. Compared with no use, daily current use and ?5 marijuana-years of cumulative use were associated with lower eGFRcys at year 10: -4.5% (95% confidence interval, -8.1 to -0.7%; P=0.02) and -3.0% (95% confidence interval, -5.6 to -0.4%; P=0.03), respectively. Marijuana use was not significantly associated with eGFRcys change, rapid eGFRcys decline, or prevalent albuminuria.ConclusionsAlthough we identified a modest cross-sectional association between higher marijuana exposure and lower eGFRcys among young adults with preserved eGFR, our findings were largely null and did not demonstrate a longitudinal association between marijuana use and eGFRcys change, rapid eGFRcys decline, or prevalent albuminuria.PodcastThis article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2017_08_24_CJASNPodcast_17_10.mp3.

Project description:BackgroundGlomerular filtration rate (GFR) is accepted as the best indicator of kidney function and is commonly estimated from serum creatinine (SCr)-based equations. Separate equations have been developed for children (Schwartz equation), younger and middle-age adults [Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation] and older adults [Berlin Initiative Study 1 (BIS1) equation], and these equations lack continuity with ageing. We developed and validated an equation for estimating the glomerular filtration rate that can be used across the full age spectrum (FAS).MethodsThe new FAS equation is based on normalized serum creatinine (SCr/Q), where Q is the median SCr from healthy populations to account for age and sex. Coefficients for the equation are mathematically obtained by requiring continuity during the paediatric-adult and adult-elderly transition. Research studies containing a total of 6870 healthy and kidney-diseased white individuals, including 735 children, <18 years of age, 4371 adults, between 18 and 70 years of age, and 1764 older adults, ?70 years of age with measured GFR (inulin, iohexol and iothalamate clearance) and isotope dilution mass spectrometry-equivalent SCr, were used for the validation. Bias, precision and accuracy (P30) were evaluated.ResultsThe FAS equation was less biased [-1.7 (95% CI -3.4, -0.2) versus 6.0 (4.5, 7.5)] and more accurate [87.5% (85.1, 89.9) versus 83.8% (81.1, 86.5)] than the Schwartz equation for children and adolescents; less biased [5.0 (4.5, 5.5) versus 6.3 (5.9, 6.8)] and as accurate [81.6% (80.4, 82.7) versus 81.9% (80.7, 83.0)] as the CKD-EPI equation for young and middle-age adults; and less biased [-1.1 (-1.6, -0.6) versus 5.6 (5.1, 6.2)] and more accurate [86.1% (84.4, 87.7) versus 81.8% (79.7, 84.0)] than CKD-EPI for older adults.ConclusionsThe FAS equation has improved validity and continuity across the full age-spectrum and overcomes the problem of implausible eGFR changes in patients which would otherwise occur when switching between more age-specific equations.

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Dataset Information

Estimated glomerular filtration rate is a poor predictor of the concentration of middle molecular weight uremic solutes in chronic kidney disease.

Background

Materials and methods

Results

Conclusion

Publications

Estimated glomerular filtration rate is a poor predictor of the concentration of middle molecular weight uremic solutes in chronic kidney disease.

Similar Datasets

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