Serum Creatinine-based Equations Research Articles

Nuclear Magnetic Resonance-Based Glomerular Filtration Rate Estimation Is More Closely Associated with Serum Vancomycin Target Trough Achievement vs. Serum Creatinine-Based Equations

Nuclear Magnetic Resonance-Based Glomerular Filtration Rate Estimation Is More Closely Associated with Serum Vancomycin Target Trough Achievement vs. Serum Creatinine-Based Equations

Utility of cystatin C and serum creatinine-based glomerular filtration rate equations in predicting vancomycin clearance: A population pharmacokinetics analysis in elderly Chinese patients.

Renal function is an important factor affecting the pharmacokinetics of vancomycin. The renal function in elderly patients gradually decreases with age. An accurate estimated glomerular filtration rate (GFR) is essential in drug dosing. The study aimed to determine the most appropriate renal function estimation equations to describe vancomycin pharmacokinetics in elderly patients using population pharmacokinetic analysis. Data were obtained retrospectively from elderly patients aged ≥65years who received vancomycin for infection from September 2016 to January 2022. Renal function was estimated using the Cockcroft-Gault equation (CG), Modification of Diet in Renal Disease equation (MDRD), three Chronic Kidney Disease Epidemiology Collaboration equations (CKD-EPIcys-scr , CKD-EPIscr , and CKD-EPIcys ) and two Berlin Initiative Study equations (BIS-1 and BIS-2). The CKD-EPIcys-scr and BIS-2 equations were based on cystatin C (Cys C) and serum creatinine (Scr). The others were based on Cys C or Scr. A nonlinear mixed effects model (NONMEM) was used to develop the population pharmacokinetic model. A total of 471 serum concentrations from 313 elderly patients were used to develop the population pharmacokinetic model. Weight and GFR were identified as significant covariates affecting the pharmacokinetics of vancomycin. Cys C and Scr-based GFR (CKD-EPIcys-scr and BIS-2) yielded significant improvement performance compared with the other equations in model building. The interindividual variability of CL was reduced from 49.4% to 23.6% and 49.4% to 23.7% in CKD-EPIcys-scr and BIS-2 based models, respectively. However, greater interindividual variabilities of CL (from 26.6% to 29.0%) were represented in the other five models which were based on either Cys C or Scr. The GFR estimated by EPIcys-scr and BIS-2 equations and vancomycin CL exhibited a good correlation (r=0.834 and 0.833). In the external validation with 124 serum concentrations, the predictive performances of the CKD-EPIcys-scr and BIS-2 based models (the mean relative prediction errors were less than 1%, the mean relative absolute prediction errors were about 23%) were also superior to the other five models (the mean relative prediction errors were about 2%, the mean relative absolute prediction errors were greater than 25%) which are based on either Cys C or Scr. In this study, we determined that the equation used to estimate GFR can affect the population pharmacokinetic model fitting result. Population pharmacokinetics model with CKD-EPIcys-scr or BIS-2 can be used to optimize vancomycin dosage in elderly Chinese patients.

Prescription audit of renally excreted drugs and vancomycin dosing for older patients with reduced kidney function

Japan has the largest aging population in the world, and kidney function declines with age. Therefore, when administering renally excreted drugs to older patients, the dosage should be adjusted according to the kidney function. This study addresses the appropriate use of renally excreted drugs in older patients in two topics. The first topic is concerned with the author’s experience with cibenzoline overdose, which led the author to conduct a survey of renally excreted drugs and establish an in-hospital prescription checking system for these drugs. The second topic clarifies the usefulness of serum creatinine-based kidney function estimation equations for predicting the area under the concentration-time curve of vancomycin in bedridden older patients. Based on these findings, the importance of pharmaceutical interventions by pharmacists in the pharmacotherapy of older patients with reduced kidney function is discussed

DETECTING CHRONIC KIDNEY DISEASE BY LEVERAGING SCREENING INITIATIVES FOR OTHER NON-COMMUNICABLE DISEASES

Objective: Early diagnosis of chronic kidney disease (CKD) slows disease progression and reduces mortality; yet screening for CKD is sparse in clinical practice. Contrary, screening for CKD risk factors like hypertension and type 2 diabetes mellitus (T2DM) are included in clinical practice guidelines in most countries. Therefore, an opportunity exists to implement CKD screening as a by-product of these existing screening programmes. To evaluate the viability of CKD screening, we used the South African Diabetes Prevention Programme (SA-DPP) to assess the yield of CKD cases. Design and method: The SA-DPP was conducted across 16 resource-poor communities in Cape Town, South Africa, between 2017 and 2019. Participants, aged 25–65 years, were recruited by random and self-selected sampling techniques. The African diabetes risk score (ADRS), which is a screening tool comprising non-laboratory-based variables including age, waist circumference and the presence of hypertension, was used to identify adults at high risk for T2DM. Those at high-risk were invited for confirmatory oral glucose tolerance test (OGTT). Kidney function was estimated using the serum creatinine-based CKD Epidemiology Collaboration equation. CKD was defined as an estimated glomerular filtration rate (eGFR) of < 90 ml/min/1.73 m2 and/or albumin-to-creatinine ratio > 3 mg/mmol. Results: Of the 2039 individuals screened in the community, 690 participants deemed at high-risk of T2DM presented at the research clinic for an OGTT. Of these individuals, 9.6% (n = 66) had diabetes and 18.1% (n = 125) had CKD, with 2.2% (n = 15) presenting with both CKD and T2DM. Most CKD cases were in the early stages of the disease, with 73.6% (n = 92), 17.6% (n = 22) and 7.2% (n = 9) presenting with stage 1–3, respectively. Of those with CKD stages 1–3, 72.8%, 68.2% and 44.5% had microalbuminuria, respectively with 27.2%, 31.8% and 11.1% presenting with macroalbuminuria. Most participants with early-stage CKD were overweight/obese (95.1%) and 47.0% had hypertension. Conclusions: By including markers of kidney function into the scope of markers collected in an existing disease screening programme, we were able to detect a great proportion of CKD cases. Therefore, by utilizing an opportunistic approach, people with early-stage CKD can be identified and appropriately treated.

Renal Dysfunction in Patients with Liver Cirrhosis

AbstractLiver cirrhosis is a major health problem that can affect people of different ages. It induces pivotal hemodynamic and metabolic systemic disturbances along with other organs dysfunction. Renal dysfunction in cirrhotic patients is not uncommon, and subtle renal impairment is an early and very frequent finding. Liver cirrhosis can afflict kidney functions through different mechanisms. Renal vasoconstriction is usually the initial response of splanchnic vasodilation and decreased effective renal plasma flow. This induces a reduction of intraglomerular pressure leading to stimulation of renin-angiotensin system to maintain the glomerular filtration rate. Other causes of renal dysfunction include electrolytes and acid-base disturbances, systemic inflammation, bile cast nephropathy, and intra-abdominal hypertension. Loss of renal reserve is usually the earliest manifestation of kidney dysfunction in cirrhotic patients. This makes the kidney supersensitive to any subsequent hemodynamic or metabolic abnormalities. Proper assessment of kidney function is one of the major challenges in cirrhotic patients. The use of serum creatinine and creatinine-based equations is inaccurate and can overestimate kidney function. Hepato-renal syndrome (HRS) is a life-threatening disorder. In the last decade, there was significant progress in understanding the mechanism of this mysterious disorder. In this article, we are focusing on different mechanisms of kidney dysfunction in cirrhotic patients and the major diagnostic and therapeutic challenges.

Indexing Estimates of GFR to Body Surface Area in Low-Resource Settings With a High Burden of Malnutrition: Evidence From Guatemala

Indexing Estimates of GFR to Body Surface Area in Low-Resource Settings With a High Burden of Malnutrition: Evidence From Guatemala

Utility of Estimated Glomerular Filtration Rate Equations in Assessing Renal Allograft Function: Are They Accurate?

Creatinine clearance (CrCl) is more accurate than other methods when assessing renal allograft function, but it is inconvenient for patients. In clinical practice, renal allograft function is often estimated using estimated glomerular filtration rate (GFR) equations. This cross-sectional study compared agreement between CrCl and serum creatinine-based equations among renal transplant recipients (RTRs) attending a transplant clinic in a tertiary center. Six equations (Cockcroft-Gault, Walser's, Nankivell, abbreviated Modification of Diet in Renal Disease [MDRD], Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI], and European Kidney Function Consortium[EKFC]) were included in the analysis. The bias, precision, and accuracy of each equation were determined. Correlation analysis was performed by determining the correlation coefficient and plotting Bland-Altmann plots. A total of 165 subjects were included in this study. Mean serum creatinine was 112.03 ± 38.67 µmol/L, and mean CrCl was 58.44 ± 21.24 mL/min/1.73 m2. Walser's equation showed strongest correlation, lowest bias, and highest accuracy of the proportion of estimated GFR falling within ±30% of CrCl, followed by the 4-variable MDRD equation. All 6 equations systematically underestimated GFR among RTRs. Walser's equation showed the best estimation of GFR, suggesting that it may be the formula of choice to estimate GFR among RTRs.

Performance of creatinine-based equations for estimating glomerular filtration rate compared to endogenous creatinine clearance.

Introduction:The guidelines recommend estimating the glomerular filtration rate using serum creatinine-based equations as a predictor of kidney disease, preferably adjusted for local population groups.Methods:Cross-sectional study that evaluated the performance of four equations used for estimating GFR compared to endogenous creatinine clearance (ClCr) in 1,281 participants. Modification of Diet equations in Renal Disease Study Group (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), CKD-EPI with adjustment for local population (CKD-EPI local) and Full Age Spectrum (FAS) in comparison with endogenous creatinine clearance (ClCr). We used the Quantile Regression to calculate the median bias, interquartile range (IQR), Bland-Altman agreement analysis and 30% margin of error (P30).Results:The mean age of participants was 52.5 ± 16.5 years with 466 women (38%), median ClCr[IQR] of 92.0 [58.0; 122.0] mL/min/1.73 m2, with 320 (25%) participants presenting ClCr < 60 mL/min/1.73 m2. The performance of the local CKD-EPI and FAS equations were superior to MDRD and CKD-EPI in relation to variability (0.92 [0.89; 0.94]) and P30 (90.5% [88.7; 92, 0]). In the group with ClCr < 60 mL/min/1.73 m2, the local CKD-EPI and FAS equations showed less variability than the CKD-EPI and MDRD (0.90 [0.86; 0.98] and 1.05 [0.97; 1.09] vs. 0.63 [0.61; 0.68] and 0.65 [0.62; 0.70], P < 0.01) and best P30 (85.5) % [81.0; 90.0], 88.0% [84.0; 92.0] vs. 52.0% (46.0; 58.0) and 53.0% [47.0; 58 .5], P < 0.01).Conclusion:Local CKD-EPI and FAS equations performed better than CKD-EPI and MDRD when compared to ClCr.

Comparability of serum creatinine-Based glomerular filtration rate equations in West African adult communities.

The clinical diagnosis of chronic kidney disease (CKD) is based on estimated glomerular filtration rate (GFR) using serum creatinine-based equations. Many formulas are used in estimating GFR. We set out to determine the degree of agreement between the Cockcroft-Gault (CG), 4-variable Modification of diet in renal disease (MDRD). Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations in our indigenous population. Adult participants were recruited across all sectors of life, education, and occupation. Blood pressure, fasting blood glucose, lipid profile, urinalysis, serum creatinine, and anthropometry were measured. Estimated GFR (eGFR) was computed using CG, MDRD, and CKD-EPI equations with and without the race factor. The Lin's concordance index (rho_c) and Bland-Altman analysis were used to determine the degree of agreement between various pairs of creatinine-based eGFR equations [MDRD with the race factor (MDRDw)]; MDRD without the race factor (MDRD); CKD-EPI with race factor (CKD-EPIw); CKD-EPI without the race factor (CKD-EPI), and the CG equation. Two hundred and sixty-one adults, mean age 47.5 ± 9.9 years, 45.2% females participated in the study. Hypertension prevalence in the study population was 41.4 (95% CI 35.3-47.6%) while diabetes mellitus was 8.1% (95% CI 5.0-12.0%). The proportion of individuals with eGFRCKD-EPI less than 60 ml/min/1.73 m2 was 17.6 (95% CI 13.2-22.8%). All pairs of rho_c were lower than the threshold of 0.9 except for eGFRCKD-EPI versus eGFRCKD-EPw. There is significant discordance in the eGFR obtained from the various serum creatinine-based GFR equations in our population suggesting the need to validate these equations and determine the best equation for our general population.

Estimating the glomerular filtration rate in pregnancy: The evaluation of the Nanra and CKD-EPI serum creatinine-based equations.

To compare the performance of the Nanra and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation for estimating glomerular filtration rate in pregnancy against the 24 h urine creatinine clearance. Pregnant women had 24 h urine collections with simultaneous serum creatinine levels. Measured 24 h urine creatinine clearance was compared to two equations: Nanra and CKD-EPI. Level of concordance was measured, with an a priori bias acceptance of ±15 ml/min/1.73 m2. A total of 53 synchronous urine and serum creatinine samples were analysed. The Nanra equation had a bias of -13.4 ml/min/1.73 m2 while the CKD-EPI equation had bias of 14.2 ml/min/1.73 m2. Both equations showed a high degree of proportional error and had poor agreement with 24 h urine creatinine clearance. None of the equations were shown to reliably measure the estimated glomerular filtration rate in pregnant women. A valid serum creatinine-based estimated glomerular filtration rate equation in pregnancy is yet to be established.

Chronic kidney disease and the risk of incident hearing loss.

There is a strikingly high prevalence of sensorineural hearing loss among patients with chronic kidney disease, with estimates ranging from 36% to 77%; however, longitudinal data are limited. We assessed whether lower baseline estimated glomerular filtration rate calculated using creatinine (eGFRCr ), as well as decline in eGFRCr over time, were associated with incident hearing loss. Serum creatinine was measured in 1,843 individuals aged 48 to 80 years without hearing loss at the start of the Epidemiology of Hearing Loss Study in 1993. Follow-up creatinine assessments were conducted at 5 (n = 1,526) and 10 (n = 1,095) years. Hearing tests were conducted at baseline and at 5-, 10-, and 15-year follow-up visits. The risk of hearing loss was assessed as a function of baseline eGFRCr as well as a function of a 20% decline in eGFRCr between baseline and 5 years and between 5 and 10 years. Cox proportional hazards regression was used to examine the risk of incident speech-frequency hearing loss, defined as pure tone average (PTA) > 25 decibels hearing loss for thresholds at 0.5, 1, 2, and 4 kHz (PTA0.5,1,2,4 ) in either ear. During 15,676 person-years of follow up, there were 802 cases of incident hearing loss. There was no statistically significant association between lower baseline eGFRCr and risk of incident hearing loss. Decline in eGFRCr was also not associated with incident hearing loss at speech frequencies. Overall, there was no significant association between eGFRCr or decline in eGFRCr using the serum creatinine-based equation and risk of incident hearing loss. 2 Laryngoscope, 130:E213-E219, 2020.

EGFR conundrum: is this the “truth” or simply another “label”?

Accurate assessment of true kidney function allows early identification, management, and prognostication of persons at risk of having kidney disease. Estimation of glomerular filtration rate using serum creatinine-based equations is frequently used in clinical practice. The majority of these equations are developed in white populations, with very few that are specific to patients of Chinese ethnic backgrounds. This new study has developed a novel estimated glomerular filtration rate equation in a multicenter, multiethnic Chinese population.

Creatinine-based estimation of glomerular filtration rate in patients with a Fontan circulation.

Patients with a Fontan circulation are at risk of renal dysfunction. We analyzed cross-sectional data in pediatric and adult Fontan patients in order to assess the accuracy of commonly used serum creatinine-based methods in estimating glomerular filtration rate (GFR). A total of 124 Fontan patients (58 children, 66 adults) were enrolled across three study centers. Measurement of GFR (mGFR) using in vivo 99m Tc-DTPA clearance was performed. Various serum creatinine-based equations were used to calculate estimated GFR (eGFR). Mean mGFR was 108±28mL/min/1.73m2 in children and 92±20mL/min/1.73m2 in adults. Fourteen children (25%) and 28 adults (45%) had an mGFR <90mL/min/1.73m2 . There was no significant correlation between mGFR and eGFR (Schwartz) in children (r=0.22, P=.1), which substantially overestimated mGFR (bias 50.8, 95%CI: 41.1-60.5mL/min/1.73m2 , P<.0001). The Bedside Schwartz equation also performed poorly in the children (r=0.08, P=.5; bias 5.9, 95%CI: -2.9-14.6mL/min/1.73m2 , P<.0001). There was a strong correlation between mGFR and both eGFR (CKD-EPI) and eGFR (MDRD) in adults (r=0.67, P<.0001 in both cases), however, both methods overestimated mGFR (eGFR(CKD-EPI):bias 23.8, 95%CI: 20-27.6mL/min/1.73m2 , P<.0001; eGFR (MDRD):bias 16.1, 95%CI: 11.8-20.4mL/min/1.73m2 , P<.0001). None of the children with an mGFR <90mL/min/1.73m2 had an eGFR (Schwartz) <90mL/min/1.73m2 . Sensitivity and specificity of eGFR (CKD-EPI) and eGFR (MDRD) for mGFR <90mL/min/1.73m2 in adults were 25% and 92% and 39% and 100%, respectively. This study identifies the unreliability of using creatinine-based equations to estimate GFR in children with a Fontan circulation. The accuracy of formulas incorporating cystatin C should be further investigated and may aid noninvasive surveillance of renal function in this population.

The role of prognostic assessment with biomarkers in chronic kidney disease: a narrative review

Chronic kidney disease (CKD) is associated with high morbidity and mortality. In the past, residual kidney function in CKD patients was assessed by serum creatinine-based equations. However, due to low accuracy of those calculations there is a need for alternative biomarkers. As cardiovascular disease is a major cause of increased mortality in patients with CKD novel biomarkers to estimate risk of cardiovascular death are vital. We reviewed articles approaching beta-trace protein, beta-2 microglobulin (B2MG) and cystatin C as alternative biomarkers to estimate glomerular filtration rate (GFR) in CKD patients. Furthermore, we included recent publications showing the role of high sensitive troponin and sFlt-1 in assessment of progressing cardiovascular disease in patients with renal failure as well as the role of inflammatory biomarkers in those patients. Lastly, we present basic research regarding the role of APOL1 gene variants, suPAR and αvβ3 integrin on decline of renal function. Measuring GFR with serum creatinine and cystatin C seems to be more accurate than equations based on beta-trace protein and B2MG. Beta-trace protein however, seems to be a predictive marker to assess risk of end-stage renal disease. A recent study showed that serum sFlt-1 levels after heparin injection could predict cardiovascular mortality in patients with chronic renal failure. High sensitive troponin is a recently introduced biomarker measuring myocardial damage in acute myocardial infarction (MI) and can predict short-term all cause death in patients with reduced GFR. Progression of renal disease is attributed to increased inflammation levels and can be predicted by measuring proinflammatory biomarkers such as TNF-receptor 1, TNF-receptor 2 and KIM-1. We gave an updated review of novel biomarkers in CKD. While some have proven useful in certain situations it is unclear whether one single biomarker for assessing renal function or predicting mortality in patients with renal failure can be found.

The Association between Glomerular Filtration Rate Estimated Using Different Equations and Mortality in the Japanese Community-Based Population: The Yamagata (Takahata) Study.

Background To evaluate renal function, the indices of estimated glomerular filtration rate (eGFR) obtained using several equations, including the Japanese versions of the serum creatinine-based MDRD equation (eGFRcreat), Chronic Kidney Disease Epidemiology Collaboration equation (eGFR-EPI), and serum cystatin C-based equation (eGFRcys), are utilized. This study prospectively examined the association between these eGFR values and all-cause mortality during a 12-year observational period in a community-based population. Methods and Results The subjects of this study were 1312 participants undergoing a health checkup, aged ≥40 years. In the total population, the mean eGFR values (mL·min−1·1.73 m−2) were 81.5 for eGFRcreat, 78.1 for eGFR-EPI, and 76.6 for eGFRcys. There were 141 deaths during the observation period, and the area under the receiver operating characteristic curve for predicting mortality was 0.59 for eGFRcreat, 0.67 for eGFR-EPI, and 0.70 for eGFRcys (all P < 0.01). In the Cox proportional analysis adjusted for age and sex, eGFRcys, but not eGFRcreat and eGFR-EPI, showed a significant association with all-cause mortality (per 15 mL·min−1·1.73 m−2 decrease: hazard ratio 1.40, 95% confidence interval 1.18–1.67). Conclusions This study revealed that eGFRcys showed lower values than eGFRcreat and eGFR-EPI and was significantly associated with all-cause mortality in the Japanese community-based population.

Prevalence of chronic kidney disease in patients with chronic hepatitis B: A cross-sectional survey.

Renal safety is a major concern during long-term antiviral treatment for chronic hepatitis B (CHB). This study aimed to investigate the prevalence of chronic kidney disease (CKD) in patients with CHB that had been treated with antiviral therapy. This was a single-centre, cross-sectional study in a real-life cohort in which all patients received antiviral treatment. Serum creatinine-based equations from the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) were used to estimate the glomerular filtration rate (GFR). CKD was defined as an eGFR <60mL/min/1.73m² or a urinary albumin to creatinine ratio ≥ 3 mg/mmol (defined as albuminuria). Univariate and multivariate analyses were conducted to determine the risk factors of CKD. A total of 1985 patients were included in the analysis from February 2015 to December 2015. The mean age and median duration of antiviral treatment was 42.20years and 17.05months, respectively. The overall prevalence of CKD was 7.9% (157/1985), with 44 patients experiencing decreased renal function (eGFR less than 60mL/min/1.73 m²) and 129 patients with albuminuria. Patients with cirrhosis had a higher prevalence of a decreased GFR (4.3% vs 1.6%, P<.001) and albuminuria (11.1% vs 5.2%, P<.001) than those without cirrhosis. In the multivariate analysis, hypertension (Odds Ratio [OR] 4.564, P<.001), diabetes mellitus (OR 2.688, P<.001) and cirrhosis (OR 1.918, P<.001) were independent factors associated with the presence of CKD. CKD was a clinically significant comorbidity in patients with CHB. Special attention should be paid to cirrhotic patients and patients with the metabolic syndrome.

Performance in adolescents of the two Japanese serum creatinine based estimated glomerular filtration rate equations, for adults and paediatric patients: A study of the Japan Renal Biopsy Registry and Japan Kidney Disease Registry from 2007 to 2013.

There are two different Japanese serum creatinine-based equations for estimated glomerular filtration rate (eGFR), for adults and paediatric patients, with both equations deemed applicable to 18-year-old subjects. This study assessed the relative accuracy of the two equations in assessing eGFR in patients aged 18years with chronic kidney disease. A total of 3042 patients (1679 males and 1363 females), aged 2-20years, who were registered in the Japan Renal Biopsy Registry or the Japan Kidney Disease Registry between 2007 and 2013 were evaluated. eGFR values derived from formulas for children (Uemura's formula) and adults (the 3-variable Japanese formula) were calculated and compared, especially in patients aged 18years. At all ages, but especially at younger ages, eGFR was significantly higher when calculated with the adult than the paediatric formula. This finding was also observed in 18-year-old adolescents with eGFR <90mL/min per 1.73 m2 (P=0.026). However, the mean difference between the two calculated eGFRs was only 2.79mL/min per 1.73 m2 . These findings indicate that both creatinine-based equations used to calculate eGFR rate in Japanese children and adults with chronic kidney disease could be used to determine eGFR in 18-year-old subjects, with the difference between the two within permissible levels for clinical use.

Comparing the GFR estimation equations using both creatinine and cystatin c to predict the long-term renal outcome in type 2 diabetic nephropathy patients

AimsThis study aimed to determine whether eGFRcre-cys and its slope could improve the prediction of the long-term renal outcome in patients with type 2 diabetic nephropathy (DN). MethodsThe cross-sectional and longitudinal analyses included 501 type 2DN patients from 2003 to 2009. GFR was estimated using either eGFRcre-cys or the serum creatinine-based equation (eGFRcre) or the cystatin C-based equation (eGFRcys), and was classified into 3 categories (≥90, 60–90, ≤60ml/min per 1.73m2). The proportion of patients was evaluated in each creatinine-calculated eGFR category for which the category was reclassified based on either cystatin C or the combined measurement. Long-term changes in eGFRcre-cys, eGFRcys and eGFRcre were estimated using linear mixed effect models. The receiver operating characteristic (ROC) curves was applied to study the sensitivity and specificity of different eGFR slopes for predicting the renal endpoint. ResultsIn the cross-sectional analyses, eGFRcre was overestimated compared to eGFRcre-cys [median bias −8.5 (95% CI: −25.01, 1.21)]. The reclassification of eGFRcre to a higher value was associated with an increased risk of ESRD [OR: 4.01 (95% CI: 2.36 to 6.82)]. In the longitudinal analyses for predicting end-stage renal disease (ERSD), the ROC curves for eGFRcre-cys (AUC=0.86±0.03) over 24months were increased compared with the ROC curves for eGFRcre and eGFRcys (p<0.05). ConclusionsThe study suggests that the eGFRcre-cys equation may be more precise and sensitive for predicting the renal outcome in T2DN patients. Tracking renal decline using eGFRcre-cys may be used as a surrogate for determining the renal endpoint in a clinical setting.

Pre-dialysis decline of measured glomerular filtration rate but not serum creatinine-based estimated glomerular filtration rate is a risk factor for mortality on dialysis.

Monitoring of renal function is important in patients with chronic kidney disease progressing towards end-stage renal failure, both for timing the start of renal replacement therapy and for determining the prognosis on dialysis. Thus far, studies on associations between estimated glomerular filtration rate (eGFR) measurements in the pre-dialysis stage and mortality on dialysis have shown no or even inverse relations, which may result from the poor validity of serum creatinine-based estimation equations for renal function in pre-dialysis patients. As decline in renal function may be better reflected by the mean of the measured creatinine and urea clearance based on 24-h urine collections (mGFR by C Cr-U ), we hypothesize that in patients with low kidney function, a fast mGFR decline is a risk factor for mortality on dialysis, in contrast to a fast eGFR decline. For 197 individuals, included from the multicentre NECOSAD cohort, pre-dialysis annual decline of mGFR and eGFR was estimated with linear regression, and classified according to KDOQI as fast (>4 mL/min/1.73 m 2 /year) or slow (≤4 mL/min/1.73 m 2 /year). Cox regression was used to adjust for potential confounders. Patients with a fast mGFR decline had an increased risk of mortality on dialysis: crude hazard ratio (HR) 1.84 (95% confidence interval: 1.13-2.98), adjusted HR 1.94 (1.11-3.36). In contrast, no association was found between a fast eGFR decline in the pre-dialysis phase and mortality on dialysis: crude HR 1.20 (0.75-1.89), adjusted HR 1.14 (0.67-1.94). This study demonstrates the importance of mGFR decline (by C Cr-U ) as opposed to eGFR decline in patients with low kidney function, and gives incentive for repeated mGFR measurements in patients on pre-dialysis care.

Initiation of Dialysis: A Mini-Review of a Changing Paradigm

A paradigm shift is occurring in the way nephrologists evaluate patients with progressive chronic kidney disease for initiation of maintenance renal replacement therapy. Serum creatinine and serum creatinine-based equations used to calculate an estimated glomerular filtration rate (eGFR) are not accurate approximations of renal function at low levels. Further complicating matters is a trend toward early initiation of dialysis, once considered beneficial since patients had better outcomes if they started dialysis before the onset of protein malnutrition. But recent data, including results of a large randomized controlled trial, suggest no benefit and possibly increased risk of death with early initiation of dialysis. This review will examine the data and where the field stands in deciding when to initiate dialysis.