Modification Of Diet In Renal Disease Glomerular Filtration Rate Research Articles

Factors Associated With Urgent-Start Peritoneal Dialysis Catheter Complications in ESRD

IntroductionUrgent-start peritoneal dialysis (PD) in patients with newly diagnosed end-stage renal disease (ESRD) is a well-tolerated alternative to hemodialysis (HD). The primary aim of this study was to identify the demographic and clinical characteristics of ESRD patients, as well as the presurgical, surgical, and postsurgical factors associated with urgent-start PD complications.MethodsA retrospective cross-sectional observational study was performed on 102 patients with ESRD who merited urgent-start PD from January 2015 to June 2019. The primary clinical outcome measures were catheter leakage, dysfunction, and peritonitis, whereas the secondary outcomes were catheter removal, repositioning, and death. Statistical inferences were made with the χ2 or Fisher’s exact test and independent samples t tests.ResultsOne hundred two subjects (65 men, 63.7%) 56.2 ± 15.1 years old were included in this study; 64 of the subjects had diabetes and hypertension (62.7%). Catheter leakage occurred in 8 patients (7.8%), catheter dysfunction in 27 patients (26.5%), and peritonitis in 14 patients (13.7%); meanwhile, catheter removal occurred in 6 patients (5.9%), catheter repositioning in 21 patients (20.6%), and death in 3 patients (2.9%). Peritonitis was associated with younger age (i.e., 47.0 ± 16.8 vs. 57.6 ± 14.4 years; P = 0.014; 95% confidence interval [CI]: 2.2–19.1; odds ratio [OR] 0.96; P = 0.018; 95% CI: 0.92–099), higher creatinine levels upon admission (i.e., 20.2 ± 9.8 vs. 14.1 ± 8.3; P = 0.014; 95% CI: −10.9 to −1.2), and heart failure (OR 4.79; P = 0.043; 95% CI: 1.05–21.88). Patients with abdominal hernia were 7.5 times more likely to have their catheter leak (OR 7.5; P = 0.036; 95% CI: 1.14–49.54). Catheter removal was associated with obesity (i.e., body mass index [BMI] of 31.6 ± 4.1 vs. 25.9 ± 4.9; P = 0.007; 95% CI: −9.8 to −1.6; OR 1.26; P = 0.013; 95% CI: 1.05–1.51) and Modification of Diet in Renal Disease glomerular filtration rate (MDRD-GFR) (i.e., 2.5 ± 0.6 vs. 3.7 ± 2.3; P = 0.003; 95% CI: 0.5–1.9).ConclusionPeritonitis was associated with younger age, higher creatinine levels upon admission, and heart failure; meanwhile, catheter removal was linked to obesity and lower glomerular filtration rate. Compared with previous reports, our study included patients in which PD was initiated shortly after catheter insertion, making the intervention a true urgent-start PD. This study contributes to the existing urgent-start PD literature by providing evidence that urgent-start PD with catheter opening within 72 hours has limited complications, making it a relatively safe option.

Efficacy of Follow-up Care System of Living Kidney Donors in Monitoring of Residual Kidney Function

BackgroundThe possibility of an increased risk of end-stage renal disease is a major concern associated with living kidney donation. Therefore, monitoring of residual kidney function becomes most essential. MethodsA data analysis of 156 living kidney donors (LKDs) was conducted. The efficacy of the long-term care system with regard to monitoring residual kidney function was evaluated. ResultsThe analyzed group consisted of 102 (65.4%) women. The mean follow-up period was 5.44 years. The rise in value of mean serum creatinine concentration after donation was observed, but it was within the range of normal during the observation period. Despite its initial decline after nephrectomy, mean glomerular filtration rate (GFR) remained >60 mL/min/1.73 m2. A MDRD (Modification of Diet in Renal Disease) GFR in the range of 45–60 mL/min/1.73 m2 was observed in 53 donors (33.97%). It was found to be <45.0 mL/min/1.73 m2 in 15 cases (9.6%). No patient developed end-stage renal disease. Only 25.0% of those analyzed had their CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) GFR estimated on 45–60 mL/min/1.73 m2 and 4.49% were found to have levels of <45 mL/min/1.73 m2 (down to 33.7 mL/min/1.73 m2). Mean postdonation CKD-EPI GFR was estimated at 69.99% of its predonation value. ConclusionA reliable qualification process could minimize the probability of kidney donation by someone with an increased risk of chronic kidney failure. The CKD-EPI formula seems to be more precise than the MDRD for estimatation of LKDs' GFR, as their loss of GFR is a result of nephrectomy and not kidney or systemic disease. Using the MDRD formula may lead to inappropriate diagnosis of CKD in some cases.

Impact of FOXP3 Polymorphisms on the Blood Level of Tacrolimus in Renal Transplant Recipients.

Tacrolimus is an immunosuppressive medication for organ transplantation. FOXP3(+) T regulatory cells (Tregs) play roles in suppression of rejection and induction of graft tolerance. This study aimed to evaluate the correlation between the polymorphism of FOXP3 and the blood level of tacrolimus in renal transplant recipients. This retrospective study included 100 renal transplant recipients receiving tacrolimus treatment and 100 healthy control subjects. Genotyping for FOXP3 rs3761547 AA, AG, GG, rs3761548 AA, AC, CC and rs223236 AA, AG, GG was performed. Concentrations of tacrolimus, creatinine, and urea nitrogen levels in blood were measured. Frequencies of genotypes of FOXP3 rs3761548 AA, AC, and CC, rs3761547 AA, AG, GG and rs 223236 AA, AG, GG in renal transplant recipients were similar to those in normal people. The blood level of tacrolimus in recipients with rs3761548 CC was significantly higher than that in recipients with rs3761548 AA and AC (P< .001). No difference in the blood level of tacrolimus was found in recipients with different genotypes of rs3761547 and rs223236. Compared to rs3761548 AA and AC groups, there was no difference of Modification of Diet in Renal Disease (MDRD) glomerular filtration rate and the level of blood urea nitrogen before transplantation; however, these 2 parameters were significantly improved after transplantation in the rs3761548 CC group. The level of tacrolimus was correlated positively with MDRD glomerular filtration rate and negatively with the blood urea nitrogen level in recipients with rs3761548 CC genotype after transplantation. Our study identified a new relationship between FOXP3 rs3761548 and the blood level of tacrolimus. These results suggest that the polymorphism of FOXP3 may affect tacrolimus pharmacokinetics.

Assessing Renal Function in Adult Myelomeningocele Patients: Correlation between Volumetric- and Creatinine-based Measurements

Objective: Renal volume-based estimates of glomerular filtration rate (GFR) using computed tomography (CT) in renal donor populations have been described. We hypothesized that the same technology would be especially useful in myelomeningocele (MMC) patients for whom standard methods of GFR assessment are inaccurate. Methods: 13 adult subjects with MMC for whom we had CTscans of the abdomen and pelvis with contrast were identified. 125 I-iothalamate studies were available for 2 of the 13 subjects. Renal volumes were calculated from CT-scans using a fitted regression model which has been previously validated in a renal donor population. A volumetric-based GFR was then calculated. Correlation between renal volume-based GFR and Modification of Diet in Renal Disease (MDRD) and Cockcroft-Gault (C-G) GFR was calculated. Results: Correlation between volume-based GFR and MDRD GFR was +0.76 (p = 0.003) while the correlation between volume-based GFR and C-G GFR was +0.68 (p = 0.010). Volumetric-based GFR was higher than 125I-iothalamate based estimates for the 2 patients for whom we had

Potential Influence of Tubular Dysfunction on the Difference Between Estimated and Measured Glomerular Filtration Rate After Kidney Transplantation

PurposeBecause no consensus exists regarding the most accurate calculation to estimate glomerular filtration rate (GFR) based on serum creatinine concentrations (sCr) after kidney transplantation, this study sought to assess the potential role of tubular dysfunction on GFR estimates using various equations as well as the effect of pharmacologic blockades on tubular secretion of creatinine on creatinine clearance (ClCr). MethodsIohexol GFR (mGFR) was performed in 17 stable kidney transplant recipients(R) at >24 months post-transplantation. Their mean age was 48.3 ± 11.3 years. All R were treated with a calcineurin inhibitor (CNI). At the time of study we measured sCr, 24 hour-ClCr, cystatin C, 24-hour proteinuria, microalbuminuria, FE Na, alfa1-microglobulinuria (alfa1-MG), and CNI concentrations. To block tubular secretion of Cr, recipients were prescribed cimetidine (2400 mg) 2 days before the sCr measurement. Additionally, to exclude dietary influences on sCr, R did not eat meat for 2 days before testing. GFR was estimated using the Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), Cockroft-Gault (C&G), and Cystatin C (Cyst C) GFR equations. Mean kidney graft function over the previous 6 months was used as the control. Pearson correlation was determined between the differences between mGFR and estimatedGFR: Iohexol minus MDRD, EPI, Cyst C or C&G GFR for paired estimates. The diagnostic accuracy of the eGFRs to detect an mGFR of 60 mL/min/1.73 m2 was examined by receiver operating characteristic curves. ResultsMean mGFR was 75.2 ± 35.8 mL/min/1.73 m2. The sCr increased but the 24-hour ClCr, MDRD, EPI, and C&G decreased after vs before cimetidine. The difference was significant for sCr (F = 12.933; P = .002) and MDRD GFR (F = 15.750; P = .001). mGFR was not significantly higher than all pair values of eGFRs, and not significantly lower than 24-hour ClCr before and after cimetidine. However, in comparison to all eGFRs, ClCr after cimetidine most approached mGFR. A significant positive correlation was observed between alfa1-MG and the difference between mGFR and MDRD (before, r = .543 [P = .045]; after cimetidine, 0.568 [P = .034]), EPI (before, r = 0.516 [P = .050]; after cimetidine, r = 0.562 [P = .036]), and ClCr (r = 0.633; P = .016), C&G (P = .581; P = .029) before cimetidine. Accuracy of eGFRs to detect mGFR of 60 mL/min/1.73 m2 showed EPI GFR before cimetidine to show diagnostic accuracy for patients with GFR >60 mL/min/1.73 m2 with a sensitivity of 81.8% and a specificity of 71.4%. ConclusionsBecause mGFR is unavailable in many transplant centers, determination of ClCr after cimetidine may help to achieve a more accurate diagnosis of CKD among transplant patients.

Renal cortical necrosis and acute kidney injury associated with Plasmodium vivax: a neglected human malaria parasite

Plasmodium vivax is causing increasingly more cases of severe malaria worldwide. There is an urgent need to reexamine the clinical spectrum and burden of P. vivax so that adequate control measures can be implemented against this emerging but neglected disease. Herein, we report a case of renal acute cortical necrosis and acute kidney injury (AKI) associated with P. vivax monoinfection. Her initial serum creatinine was 7.3 mg/dL on admission. Modification of Diet in Renal Disease (MDRD) Study glomerular filtration rate (GFR) value was 7 mL/min/1.73 m(2) (normal kidney function-GFR above 90 mL/min/1.73 m(2) and no proteinuria). On follow-up, 5 months later, her SCr. was 2.43 mg/dl with no proteinuria. MDRD GFR value was 24 mL/min/1.73 m(2) suggesting severe chronic kidney disease (CKD; GFR less than 60 or kidney damage for at least 3 months), stage 4. Our case report highlights the fact that P. vivax malaria is benign by name but not always by nature. AKI associated with P. vivax malaria can lead to CKD. Further studies are needed to determine why P. vivax infections are becoming more severe.

The Gly460Trp polymorphism of alpha-adducin gene as a predictor of renal function decline over 4 years of follow-up in an apparently healthy Chinese population

There were conflict data between alpha-adducin Gly460Trp genetic variant and changes of renal function. We conducted a prospective study to investigate the influence of alph-adducin Gly460Trp polymorphism on the quantitative changes of renal function. Of 1500 people screened, 112 non-diabetic normotensive elderly Chinese were recruited and received biochemistry examination at the baseline, at the second and fourth year follow-up. Serum creatinine and calculated renal parameter, using Modification of Diet in Renal Disease (MDRD) Study, were used to evaluate renal function and their progression. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism. Age was 71.9 ± 3.7 years (range 60-81). Serum creatinine and MDRD glomerular filtration rate (GFR) were significantly worsened at the 2 and 4-year follow-up (all P < 0.001). The magnitude of 4-year decline of MDRD GFR was significantly higher in subjects carrying the a-adducin Gly460Trp G-allele than TT genotype (P = 0.045). The multivariate analyses showed that a-adducin Gly460Trp (P = 0.034), baseline MDRD GFR (P < 0.001), diastolic blood pressure (P = 0.021) and body weight (P = 0.022) could independently predict 4-year change of MDRD GFR. This longitudinal study showed that the aging process was associated with decline of renal function in the healthy elderly. The alpha-adducin Gly460Trp gene polymorphism might modulate these changes in the Chinese. Thisprovides further knowledge essential in the assessment of renal disease and determination of renal function in the older subjects.

Comparison of glomerular filtration rate estimated by plasma clearance method with modification of diet in renal disease prediction equation and Gates method

Glomerular filtration rate (GFR) prediction equations are widely used in clinical practice for quick assessment of kidney function. Gates method using radionuclide technique is an alternative to prediction equations for quick assessment of GFR. Aim of the study was to compare Gates method and modification of diet in renal disease (MDRD) equation in a sizeable patient population with wide range of renal function to evaluate their clinical utility. GFR was estimated in 897 subjects with wide range of renal function by gates method, and MDRD equation and results were compared against measured GFR. Subjects were divided in to 4 groups (0-30 ml, 31-60 ml, 61-90 ml, >90 ml) on the basis of measured GFR and comparison between two methods done through linear regression analysis. Analysis of R2 indicated that 56% of the interindividual variability for Gates GFR was in accordance to variation in measured GFR, in the GFR range of (0-30 ml), this value dropped to 39% in the GFR range of 31-60 ml, 40% in the GFR range of 61-90 ml, 26.4% in the GFR range of >90 ml, the corresponding figure for MDRD GFR were 47.9%, 31.1%, 17.6% and 16.1%, respectively. Gates method is more precise for GFR estimation at all levels of renal function.

Serum cystatin C in advanced liver cirrhosis and different stages of the hepatorenal syndrome

Background and study aims The hepatorenal syndrome (HRS) is classified into two types (HRS-2 and HRS-1) based on mild or high serum creatinine elevations. Although it has been identified as an early marker of renal dysfunction, data are lacking about cystatin C across the wide range of renal changes in end-stage liver disease. This study investigates serum cystatin C and creatinine in patients with advanced liver cirrhosis and classic HRS throughout its whole spectrum. Patients and methods Serum cystatin C immunonephelometric measurements were obtained from 65 Child–Pugh C patients: 32 with normal creatinine, 17 with HRS-2 and 16 with HRS-1. The glomerular filtration rate (GFR) was estimated according to modification of diet in renal disease (MDRD) and the Hoek formulae (creatinine- and cystatin C-based, respectively) with staging of renal dysfunction severity into an increasing order from 1 to 5. Results Early HRS was identified by the raised cystatin C in 56.3% of patients having normal creatinine. Cystatin C correlated significantly with creatinine in HRS-2 ( r = 0.74; p < 0.001) and showed a significantly lower multiplication ratio (folds of rise) compared to creatinine in HRS-1 patients ( p < 0.01). There was no satisfactory agreement between MDRD and Hoek GFR staging ( k = 0.29). Conclusions The ‘early’ HRS identified by a rise in cystatin C in cases with advanced cirrhosis was found to be common and can be added to the already classified two types, as type-3 HRS. Compared to creatinine, cystatin C provides no better information in HRS-2, and underestimates the renal deterioration in HRS-1. Further studies are required to determine the course of the early HRS.

Estimating glomerular filtration rate: comparison of the CKD-EPI and MDRD equations in a large UK cohort with particular emphasis on the effect of age

The chronic kidney disease (CKD)-Epidemiology Collaboration (CKD-EPI) equation was developed to address the underestimation of measured glomerular filtration rate (GFR) by the Modification of Diet in Renal Disease (MDRD) equation at levels >60 mL/min/1.73 m(2). To assess the impact of the CKD-EPI equation on the estimation of GFR in a large adult UK population (n = 561,400), particularly looking at the effect of age. Serum creatinine results (ID-MS-aligned enzymatic assay) were extracted from the pathology database during 1 year on adult (≥ 18 years) patients from primary care. The first available creatinine result from 174,448 people was used to estimate GFR using both equations and agreement assessed. Median CKD-EPI GFR was significantly higher than median MDRD GFR (82 vs. 76 mL/min/1.73 m(2), P < 0.0001). Overall mean bias between CKD-EPI and MDRD GFR was 5.0%, ranging from 13.0% in the 18-29 years age group down to -7.5% in those aged ≥ 90 years. Although statistically significant at all age groups the difference diminished with age and the agreement in GFR category assignment increased. Age-adjusted population prevalence of CKD Stages 3-5 was lower by CKD-EPI than by MDRD (4.4% vs. 4.9%). CKD-EPI produces higher GFR and lower CKD estimates, particularly among 18-59 year age groups with MDRD estimated GFRs of 45-59 mL/min/1.73 m(2) (Stage 3A). However, at ages >70 years there is very little difference between the equations, and among the very elderly CKD-EPI may actually increase CKD prevalence estimates.

GFR estimating equations, CKD prevalence and the public health

GFR estimating equations, CKD prevalence and the public health

The A1166C polymorphism of angiotensin II Type 1 receptor as a predictor of renal function decline over 4 years follow-up in an apparently healthy Chinese population

The angiotensin II Type 1 receptor (AT1R) A1166C (rs5186) genez polymorphism is equivocally associated with the patients' susceptibility to chronic kidney disease or end-stage renal disease. We conducted a prospective study to investigate the influence of AT1R A1166C gene polymorphism on the quantitative changes of renal function. Of 1500 people screened, 112 non-diabetic normotensive elderly Chinese were recruited and received biochemistry examination at the baseline, at the second and fourth year follow-up. Serum creatinine and calculated renal parameters, using Cockroft-Gault (CG) formula, Modification of Diet in Renal Disease (MDRD) Study and abbreviated MDRD (abMDRD) equation, were used to evaluate renal function and their progression. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism. Age was 71.9 +/- 3.7 years (range 60 - 81). Serum creatinine, CG creatinine clearance (CrCl), MDRD and abMDRD glomerular filtration rate (GFR) were significantly decreased at the 2 and 4-year follow-up (all p < 0.001). The magnitude of 4-year decline of above four renal parameters was significantly higher in subjects carrying the AT1R AA genotype than C-allele carriers (p = 0.014, 0.033, 0.008 and 0.014 for creatinine, CG CrCl, MDRD and abMDRD GFR, respectively). This association was still significant in multivariate analyses (p = 0.019, 0.045, 0.035 and 0.018, respectively). This longitudinal study showed that the aging process was associated with decline of renal function in the healthy elderly. The AT1R A1166C gene polymorphism might modulate these changes in the Chinese. This provides further knowledge essential in the assessment of renal disease and determination of renal function in the older subjects.

Comparison of the Modification of Diet in Renal Disease and Cockcroft‐Gault Equations for Dosing Antimicrobials

To determine the concordance between the Modification of Diet in Renal Disease (MDRD) and Cockcroft-Gault equations for glomerular filtration rate (GFR) estimation, the impact of using each equation on antimicrobial dosing, the difference in estimated GFR in patients with acute kidney disease (AKD) versus chronic kidney disease (CKD), and the correlation between the MDRD, Cockcroft-Gault equation, and expert medical opinion for estimating GFR in patients with AKD. Retrospective cohort study. A 689-bed academic medical center. A total of 372 adults hospitalized with either AKD or CKD between January 1, 2007, and May 31, 2007, and who received at least one antimicrobial drug; patients with stage 1 or 2 CKD or those receiving dialysis were excluded. Data were collected from electronic medical records on patient characteristics, laboratory values, antimicrobial drugs requiring dosage adjustment due to renal dysfunction, and estimated GFRs provided by the laboratory (MDRD estimation). In addition, estimated GFRs were calculated using the Cockcroft-Gault equation. For patients with AKD, a third GFR was estimated by a nephrologist. For all patients, the MDRD GFR was significantly higher than the Cockcroft-Gault GFR (p<0.001). Level of concordance for the need for dosage adjustment based on the two equations was moderate (kappa coefficient 0.57, 95% confidence interval 0.5-0.63); 99.1% of patients with discordant dose recommendations would receive a higher dose if the MDRD GFR was used. In the AKD versus CKD groups, mean MDRD GFR was significantly higher than the Cockcroft-Gault GFR in both groups (p<0.0001), but the difference was significantly greater in the CKD group (p<0.0001). In patients with AKD, the GFR estimated by expert opinion was greater than that estimated by the Cockcroft-Gault equation (p=0.04), but was similar to the MDRD equation (p=0.07). The estimated GFR obtained with the MDRD equation was consistently higher than that from the Cockcroft-Gault equation in patients with AKD or CKD. In patients with AKD, the MDRD GFR more closely correlated with expert opinion than the Cockcroft-Gault, suggesting that the MDRD method may be applicable to this patient population. Moderate concordance between the two equations for the need for antimicrobial dosage adjustment due to renal dysfunction was found, but the specific dosage change was different for approximately 40% of patients, with 99% receiving higher doses when the MDRD GFR is used. These dosing differences may be significant, depending on drug safety profile, type of infection, and causative pathogen.

Incidence of Diabetic Foot and Associated Risk Factors in Type 2 Diabetic Patients: A Five-year Observational Study

Background: The frequency of lower extremity amputation due to diabetic foot has been increasing in type 2 diabetic patients. The aim of this study was to observe the incidence, clinical aspects and associated risk factors for diabetic foot. Methods: We evaluated the incidence of diabetic foot through a five-year observation of type 2 diabetic patients who presented to St. vincent's Hospital between Januar y and December 2003. To identify the risk factors for diabetic foot, we evaluated mean glycosylated hemoglobin A1c (HbA1c) every six months and assessed renal function based on the existence of proteinuria and estimated glomerular filtration rate (GFR) using the Modification of Diet in Renal Disease (MDRD) equation. Patients were also evaluated for retinopathy, peripheral neuropathy and autonomic neuropathy usi ng Ewing's method. Results: From an initial pool of 613 patients, the observational study o f 508 patients (82.9%) was completed. The mean age, duration of diabetes and HbA1c were 50.3 ± 10.6 yrs, 7.2 ± 6.5 yrs and 8.8 ± 2.1%, respectively. Diabetic foot occurred in 32 patients (6.3%). The incidence of diabetic foot increased when diabetic retinopathy (OR = 6.707, 2.314~19.439), peripheral neuropathy (OR = 2.949, 1.075~8.090), and autonomic neuropathy (OR = 3.967, 1.476~10.660) were present and when the MDRD GFR (OR = 5.089, 1.712~15.130) decreased. Mean HbA1c (OR = 12.013, 1.470~98.179) was found to be an independent risk factor for diabetic foot. Conclusion: The present study confirmed the importance of intensive glycemic control and the role of autonomic dysfunction in the development of diabetic foot. In addition, diabetic retinopathy and impaired renal function proved to be factors associated with the occurrence of diabetic foot. Therefore, intensive glycemic control, as well as periodic examination of renal function, are essential for the prevention of diabetic foot. (Korean Diabetes J 33:315-323, 2009)

Variation of serum creatinine, cystatin C, and creatinine clearance tests in persons with normal renal function

Background To determine the potential sensitivity of several renal function tests for detecting early changes in renal function, we compared the within-individual (W-I) variation over 5 months of serum creatinine, serum cystatin C, and creatinine clearance. Methods On 31 healthy subjects, blood and timed urine specimens were collected once each month to get 6 collections. Creatinine (enzymatic) in serum and urine and cystatin C (immunonephelometric) in serum were measured and glomerular filtration rate (GFR) by creatinine clearance and the Modification of Diet in Renal Disease (MDRD) equation were calculated. To compare W-I variations between different creatinine methods, we also measured creatinine by both enzymatic and kinetic alkaline picrate methods on 15 sets of frozen samples. Results For the 31 volunteers, the mean W-I variations for serum creatinine (5.8%) and cystatin C (5.4%) were both much lower than the W-I variation of creatinine clearance (18.7%). As expected, the MDRD GFR had a similar W-I variation (6.7%) to that of serum creatinine and its values were markedly different than GFR by creatinine clearance. On the 15 sets of frozen samples, the W-I variation of creatinine measured by the enzymatic method (CV 5.2%) was slightly less than by the picrate method (CV 6.2%). Conclusions The low W-I variation of both serum cystatin C and serum creatinine suggests that serial measurements of either would detect a changes in renal function earlier than would GFR by creatinine clearance or MDRD equation, which allows reporting only for GFRs < 60 ml/min/1.7 m 2. While we measured only creatinine clearance, the large variability, difficulty, and cost of all clearance measurements make them impractical for routine monitoring of patients.

The D Allele of Angiotensin‐Converting Enzyme Polymorphism as a Predictor of Renal Function Decline over 4 Years in an Apparently Healthy Chinese Population Aged 60 and Older

To test the association between angiotensin-converting enzyme (ACE) insertion or deletion (I/D) polymorphism and decline of renal function in people aged 60 and older. Population-based prospective study with 4-year follow-up. Department of Internal Medicine and Family Medicine, Kaohsiung Medical University (KMU) Hospital and Graduate Institute of Medicine and Public Health, KMU. Of 1,500 people screened, 193 subjects were enrolled, and 144 completed 4 years of follow-up, 112 non-diabetic normotensive elderly people were analyzed. Subjects received biochemistry examination at baseline and at 2- and 4-year follow-ups. Serum creatinine and calculated renal parameters, including the Cockroft-Gault (CG) formula, the Jelliffe formula, and the Modification of Diet in Renal Disease (MDRD) Study equation, were used. Genetic polymorphism was analyzed according to the polymerase chain reaction. The mean age+/-standard deviation of the subjects was 71.9+/-3.7 (range 60-81). Serum creatinine, CG creatinine clearance (CrCl), Jelliffe CrCl, and MDRD glomerular filtration rate (GFR) were significantly lower at the 2- and 4-year follow-ups (all P < or = .001). At the 4-year follow-up, the magnitude of declines of the above four renal parameters was significantly higher in subjects with the ACE D allele than in the non-D-allele carriers (P = .01, .01, .04, and .01 for creatinine, CG CrCl, Jelliffe CrCl, and MDRD GFR, respectively). This association was still significant in multivariate analyses (P < or = .02 for all parameters). This longitudinal study showed the ACE I/D gene polymorphism might modulate renal function decline in elderly Chinese. This provides further knowledge essential in the assessment of renal disease and determination of renal function in older Chinese.

Lower hemoglobin concentrations and subsequent decline in kidney function in an apparently healthy population aged 60 year and older

BackgroundAnemia and decreased kidney function are recognized as risk factors for morbidity and mortality in the elderly. The role of hemoglobin in renal function changes among elderly patients is not fully understood. MethodsOf 1500 people screened, 121 normotensive non-diabetic elderly patients were recruited, and underwent biochemistry examinations at the baseline, second and fourth years of a 4-year longitudinal study. Serum creatinine and calculated renal parameters, including the Cockroft–Gault (CG) formula, Modification of Diet in Renal Disease (MDRD) Study and abbreviated MDRD (abMDRD) equations were used to evaluate renal function and progression of kidney disease. Chronic kidney disease (CKD) was defined as a glomerular filtration rate (GFR) of <60 ml/min/1.73 m2. Multivariate regression analyses were used to explore predictors for decline in renal parameters. ResultsAges ranged from 60 to 81 year (mean: 71.8±3.8). Baseline hemoglobin concentrations ranged from 11.9 to 17.3 g/dl (mean: 14.1±1.1). Serum creatinine increased and CG creatinine clearance (CrCl), MDRD and abMDRD GFR decreased during follow-up (all p≤0.001). The prevalence of CKD significantly increased only in those with baseline hemoglobin concentrations of <14 g/dl (p≤0.03, based on findings of both MDRD and abMDRD GFR). Baseline hemoglobin correlates with 4-year changes of MDRD and abMDRD GFR in univariate (both p<0.001) and multivariate regression analyses (both p<0.05). ConclusionsThis longitudinal study revealed that the aging process was associated with decline of renal function in the elderly. Because hemoglobin concentrations are an independent predictor for subsequent decline in kidney function, it should be considered in the assessment of renal disease and GFR in the elderly.

Cystatin C Is Not Superior to Creatinine-Based Models in Estimating Glomerular Filtration Rate in Former Kidney Donors

The long-term renal consequences of kidney donation need to be accurately quantitated. Cystatin C is a freely filtered glycoprotein that may not have the limitations of creatinine as a measure of glomerular filtration rate (GFR). Whether cystatin C is superior to creatinine-based estimates of GFR in those who have donated a kidney in the past has not been tested. We assessed the performance of seven cystatin C and two creatinine-based GFR prediction equations in 187 former kidney donors against iohexol GFR for measuring GFR. We calculated bias, precision, and relative accuracy of these models. The majority of former donors had a GFR >60 mL/min/1.73 m(2). All cystatin C models, except the Rule model, overestimated GFR (range 5.3-31.4 mL/min/1.73 m(2)). Among the cystatin C models, the Hoek and Rule formulas were least biased at 5.3 and -3.8 mL/min/1.73 m(2), most precise at 0.41, and were within 30% of iohexol GFR, 89.3 and 96% of the time, respectively. The Modification of Diet in Renal Disease (MDRD) formula underestimated GFR by 7.2 mL/min/1.73 m(2), was most precise (R(2)=0.47) and fell within 30% of measured GFR at the highest frequency of 96%. When all models were given a rank based on their performance in the bias, precision and accuracy domains, the MDRD model was clearly superior. The MDRD equation is superior to cystatin C-based equations for estimating GFR in former kidney donors. Creatinine measurement is cheaper and the MDRD GFR is given out by most laboratories and therefore it should be the preferred model in this population.

Is Modification of Diet in Renal Disease Formula Similar to Cockcroft-Gault Formula to Assess Renal Function in Elderly Hospitalized Patients Treated With Low-Molecular-Weight Heparin?

Repeated administration of low-molecular-weight heparin (LMWH) to elderly patients with an impaired renal function may lead to an accumulation effect with an increased risk of bleeding. In this setting, Cockcroft-Gault (CG) is the most widely used formula for glomerular filtration rate (GFR) estimation. In hospitalized patients over the age of 70, the six-variable Modification of Diet in Renal Disease (MDRD) formula was compared with the CG formula to detect patients with renal impairment who are at higher risk of bleeding when treated with LMWH. We combined retrospective data from 366 patients aged 86.2 +/- 6.6 years, treated with LMWHs. CG and MDRD GFR estimates were compared using the Bland-Altman method and the agreement between the two formulae by the kappa coefficient. The mean CG and MDRD estimated GFR were 45.9 +/- 21.9 mL/min and 75.6 +/- 32.6 mL/min/1.73 m(2), respectively, with a mean bias of 29.6 mL/min. The concordance between the formulae to classify patients into stages of kidney disease was very poor (weighted kappa = 0.17): 21.8% patients had severe renal function impairment with the CG formula versus 1.3% with the MDRD formula. In our population, the MDRD thresholds that would correspond to CG estimates of 30 mL/min and 60 mL/min were found at 63 mL/min/1.73 m(2) and 80 mL/min/1.73 m(2), respectively. In elderly patients, GFR estimates using MDRD and CG formulae differ widely and identify different numbers of individuals with kidney disease. Prospective comparative studies are needed to validate these formulae and their different thresholds to better detect elderly patients at higher risk of bleeding when treated with LMWH.

Kidney Dimensions at Sonography are Correlated With Glomerular Filtration Rate in Renal Transplant Recipients and in Kidney Donors

The gold standard to assess renal function is the measurement of glomerular filtration rate (GFR). For practical reasons, renal function is often evaluated from serum creatinine (S Cr) or cystatin C (S Cys), and GFR is predicted from SCr. Ultrasound scanning of the kidneys is used only to evaluate renal morphology. The aim of this study was to evaluate the relationship between sonographic renal dimensions and GFR in renal transplant recipients and in kidney donors. GFR (urinary clearance of 99mTc-DTPA), S Cr, and S Cys were measured in 33 donors (28 females [F], 5 males [M]; SCr, 0.81–1.90 mg/dL) and 30 recipients (8 F, 22 M; SCr, 0.96–2.42 mg/dL). GFR was also predicted using the Cockcroft and Gault (CG) formula and with the simplified Modification of Diet in Renal Disease (MDRD) formula. Length, width, and depth of kidneys and renal sinus were measured using renal sonography. Among sonographic measurements, kidney length showed the best correlation with GFR. A closer correlation with GFR was found in donors ( r = 0.639; P < .00007) than in recipients ( r = 0.511; P < .005). In either case, the correlation of kidney length with GFR was greater than that of S Cr or S Cys, and similar to that of CG or MDRD GFR. Accuracy of kidney length as an indicator of GFR impairment was not statistically different from laboratory tests. Only in donors did CG show better accuracy. In conclusion, renal dimensions at sonography closely correlated with GFR. Thus, renal sonography can give information also on the function of the renal graft and of the remaining kidney of living donors.