MDRD Equation Research Articles

Prevalence and staging of chronic kidney disease in renal transplant recipients

Diagnosis and staging of chronic kidney disease (CKD) is important for management and prevention of renal disease progression. It is unclear whether K/DOQI guidelines of the National Kidney Foundation are applicable to diagnosis of CKD in renal transplant recipients (RTRs) and which method is most appropriate for estimating glomerular filtration. To determine the prevalence and staging of CKD in RTRs, according to K/DOQI guidelines, and the prevalence of complications of CKD. This cross-sectional study included RTRs at least six months post-transplantation followed at a single out-patient service. The glomerular filtration rate (GFR) was estimated with two different equations: the MDRD equation (Modification of Diet in Renal Disease) with four variables (age, creatinine level, gender, and race) and the Cockcroft-Gault (CG) formula. Patients with GFR more than 60 mL/min/1.73 m2 were diagnosed with CKD only in the presence of renal damage (hematuria, proteinuria, or evidence of injury in renal biopsy). CKD staging was compared to the two equations and the prevalence of complications was determined. The study evaluated 241 RTRs (average age: 40.6 +/- 12.5 yr, 62.2% male; 4.5% black, 50.6% from cadaveric donors). Average follow-up time was 6.8 +/- 6.1 yr and the average baseline creatinine level was 1.48 +/- 0.72 mg/dL. CKD was diagnosed in 70.5% of RTRs, of whom 52.9% (MDRD)/47.6% (CG) were classified as Stage III (GFR: 30-59 mL/min/1.73 m2). The agreement between the two methods was very close with regard to CKD diagnosis (kappa = 0.92) and close for stage-dependent prevalence (kappa = 0.68). The prevalence of anemia, hypocalcemia, hyperphosphatemia (HF), hyperuricemia (HU), and systemic arterial hypertension (SAH) was 10.6%, 7.6%, 10.3%, 54%, and 73.4% for patients with CKD. Significant differences were observed for HU, HF and SAH in patients without CKD. Anemia, HU and SAH were associated with CKD stage (p < 0.001). The prevalence of CKD in the study population was high (70.5%). The two equations tested correlated closely when used for GFR estimation. Routine CKD staging in RTRs would provide patients with safer and more appropriate management.

High prevalence of undiagnosed chronic kidney disease among at-risk population in Kinshasa, the Democratic Republic of Congo

BackgroundThere is limited knowledge of Chronic Kidney Disease (CKD) among high risk populations, especially in the developing countries. We report our study of testing for CKD in at-risk subjects.MethodsIn a cross-sectional study, 527 people from primary and secondary health care areas in the city of Kinshasa were studied from a random sample of at-risk out-patients with hypertension, diabetes, obesity, or HIV+. We measured blood pressure (BP), blood glucose level, proteinuria, body mass index, and estimated glomerular filtration rate (eGFR by MDRD equation) using calibrated creatinine levels based on one random measurement. The associations between health characteristics, indicators of kidney damage (proteinuria) and kidney function (<60 ml/min/1.73 m2) were also examined.ResultsThe prevalence of CKD in this study was 36%, but only 12% were aware of their condition. 4% of patients had stage 1 CKD, 6% stage 2, 18% stage 3, 2% stage 4, and 6% had stage 5. 24 hour quantitative proteinuria (>300 mg/day) was found in 19%. In those with the at-risk conditions, the % of CKD was: 44% in patients with hypertension, 39% in those with diabetes; 16% in the obese and 12% in those who were HIV+. 82% of those with a history of diabetes had elevated serum glucose levels at screening (≥ 126 mg/dl). Only 6% of individuals with hypertension having CKD had reduced BP to lower than 130/80 mmHg. In multivariate analysis, diabetes, proteinuria and hypertension were the strongest determinants of CKD 3+.ConclusionIt appears that one out of three people in this at-risk population has undiagnosed CKD and poorly controlled CKD risk factors. This growing problem poses clear challenges to this developing country. Therefore, CKD should be addressed through the development of multidisciplinary teams and improved communication between traditional health care givers and nephrology services. Attention to CKD risk factors must become a priority.

Correlation of cardiovascular risk factors versus glomerular filtration rate in healthy population

To evaluate the relationship between cardiovascular risk factors and glomerular filtration rate in healthy population. A community-based cross-sectional study was conducted in Shenyang. The Framingham sex-specific risk equation was employed to evaluate the cardiovascular risk factors of 501 healthy study objects, calculate Framingham risk score and estimate the risk of 10-year coronary heart disease (CHD). A total of 501 study subjects were then divided into 3 groups according to 10-year CHD risk: low risk group (< 10%), moderate risk group (10% -20%) and high risk group ( > 20%). Study subjects were also divided into 5 groups according to age: < or = 44 years old; 45 - 54 years old; 55 - 64 years old; 65 - 74 years old and > or = 75 years old. The Cockcroft-Gault equation (GFR(CG)), abbreviated MDRD equation (GFR(MDRD1)) and modified MDRD equation (GFR(MDRD2)) were used to estimate glomerular filtration rate (GFR). Glomerular filtration rate (GFR) were compared among different risk groups and correlation coefficients between Framingham risk score and glomerular filtration rate calculated. GFR(CC), GFR(MDRD1) and GFR(MDRD2) in the low risk group was [(103 +/- 27) ml x min(-1) GFR(MDRD2) in moderate risk group all decreased [(84 +/- 24) ml x min(-1) x (1.73 m2) (-1), (101 +/- 27) ml x min(-1) x (1.73 m2) (-1), (124 +/- 33)ml x min(-1) (1.73 m2) (-1), all P < 0.01]. GFR(CG), GFR(MDRD1) and GFR(MR(MDRD2) in the high risk group all decreased [(71 +/- 15) ml x min(-1) (1.73 m2) (-1), (88 +/- 15) ml x min(-1) x (1.73 m2)(-1), (109 +/-18)ml x min(-1) x (1.73 m2) (-1), all P < 0.01]. The GFR(CG), GFR(MDRD1) and GFR(MDRD2) in the high risk group all decreased compared with the moderate risk group (P < 0.05). There was a significantly inverse correlation between Framingham risk score and GFR with the Pearson correlation coefficient -0.586 (GFR(CG), P < 0.01) and -0.449 (GFR(MDRD1) and GFR(MDRD2), P < 0.01). There is an inverse correlation between cardiovascular risk factors and GFR in healthy population. With the increasing of risk factors and their severity, Framingham risk score increases and GFR decreases.

Autologous Hematopoietic Stem Cell Transplantation May Reverse Renal Failure in Patients with Multiple Myeloma

Approximately 20% of patients with multiple myeloma (MM) have renal failure at diagnosis, and about 5% are dialysis-dependent. Many of these patients are considered ineligible for autologous hematopoietic stem cell transplantation (auto-HSCT) because of a high risk of treatment-related toxicity. We evaluated the outcome of 46 patient with MM and renal failure, defined as serum creatinine >2 mg/dL sustained for >1 month before the start of preparative regimen. Patients received auto-HSCT at our institution between September 1997 and September 2006. Median serum creatinine and creatinine clearance (CrCl) at auto-HSCT were 2.9 mg/dL (range: 2.0-12.5) and 33 mL/min (range: 8.7-63), respectively. Ten patients (21%) were dialysis-dependent. Median follow-up in surviving patients was 34 months (range: 5-81). Complete (CR) and partial responses (PR) after auto-HSCT were seen in 9 (22%) and 22 (53%) of the 41 evaluable patients, with an overall response rate of 75%. Two patients (4%) died within 100 days of auto-HSCT. Grade 2-4 nonhematologic adverse events were seen in 18 patients (39%) and included cardiac arrythmias, pulmonary edema, and hyperbilirubinemia. Significant improvement in renal function, defined as an increase in flomerular filtration rate (GFR) by 25% above baseline, was seen in 15 patients (32%). Kaplan-Meier estimates of 3-year progression-free survival (PFS) and overall survival (OS) were 36% and 64%, respectively. In conclusion, auto HSCT can be offered to patients with MM and renal failure with acceptable toxicity and with a significant improvement in renal function in approximately one-third of the transplanted patients. In this analysis, a melphalan (Mel) dose of 200 mg/m(2) was not associated with an increase in toxicity or nonrelapse (Mel) mortality (NRM).

Modified MDRD equation in predicting glomerular filtration rate in patients with chronic kidney disease: an assessment of applicability

Objective:To evaluate the applicability of modified MDRD equation in predicting Glomerular filtration rate in patients with chronic kidney disease(CKD).Methods: Totally 481 CKD patients,who were diagnosed based on K/DOQI guideline from Jan.2005 to Jan.2007 in our hospital,were enrolled in this study.The sex,age,body weight and height of patients were recorded;the plasma creatinine,serum albumin and 99mTc-GFR(standardized by body surface area) were measured.GFRs were estimated by abbreviated MDRD equation and the modified MDRD equation separately.The bias,accuracy and precision of both equations were compared.Results: The estimated GFRs(eGFRs) by both equations were significantly correlated with the rGFR(P0.01).Except for the slightly decreased precision,the modified MDRD equation showed great improvements in the 5%,30%,and 50% accuracy and bias when compared with the original abbreviated MDRD equation(P0.05).Compared with the original equation,the modified MDRD equation showed smaller bias in all stages of CKD except for stage 5(P0.05).The modified MDRD equation also decreased the absolute bias and improved the 30% accuracy in stage 2 CKD(P0.01).Conclusion: Compared with original equation,the modified MDRD equation has great advantages in predicting the total GFR and GFRs at different CKD stages.Currently it can be used in predicting the GFR of Chinese CKD patients.

Residual renal function at the start of dialysis and clinical outcomes

This study evaluates the association between estimated GFR (eGFR) at the start of dialysis and mortality within Europe. Renal registries participating in the ERA-EDTA Registry were asked to provide data on serum creatinine recorded 0-4 weeks before the start of dialysis in incident dialysis patients in 1999 and 2003. Within this cohort study, data were available in 11 472 patients from nine national or regional European renal registries. Cox regression analyses were performed to examine the association between GFR estimated by the four-variable MDRD equation (eGFR) and all-cause mortality, using a follow-up through 31 December 2005. In the 2003 data, the mean eGFR was 8.6 ml/min/1.73 m(2). The unadjusted survival analyses showed that an increase in eGFR of 1 ml/min/1.73 m(2) was associated with a higher mortality risk (HR = 1.03; 95% CI: 1.03-1.04) that remained similar after adjustment for age, gender, primary renal disease, treatment modality, country and comorbidity. The findings were consistent across gender, treatment modalities, geographical regions and time periods (2003 versus 1999), but the association between a higher eGFR at the start of dialysis and mortality was the strongest in the youngest age groups and in patients with glomerulonephritis. Analyses at centre level showed that a 10% increase in the percentage of patients starting dialysis at high eGFR levels (>or=10.5 ml/min) was associated with a 22% higher mortality risk (HR = 1.22; 95% CI: 1.18-1.26). This European study showed that a higher eGFR at the start of dialysis was associated with a higher mortality risk. However, an answer to the question when to start dialysis needs to come from randomized controlled trials.

Estimating GFR in children: Schwartz redux

one of the early products of the Chronic Kidney Disease in Children (CKiD) study has been an updated equation for estimating GFR in children on the basis of demographic and laboratory parameters. This formula is comparable in form and performance to the MDRD equations for adults in clinical trials first published a decade ago.

Insuficiencia renal oculta y prescripción de fármacos en atención primaria

Objective To study the prevalence of chronic kidney disease (CKD) [glomerular filtration rate (GFR) <60 ml/min/1.73 m 2] and occult kidney disease (OKD) (normal serum creatinine values with GFR <60) in elderly patients. Design Retrospective, observational study. Setting Four primary care centres in the province of Huesca, Spain. Participants About 4014 patients older than 65 years were randomly selected. Main measurements GFR was calculated for all subjects using the four-variable modified MDRD equation. We registered all drugs prescriptions to the patients during a period of twelve months focusing on the potential nephrotoxic drugs. Results After exclusions, GFR was estimated in 3286 patients (1424 men of 75.49±6.6 years and 1862 women of 76.29±7.04 years; P=.001). The prevalence of CKD was 21.2%. A total of 10.1% of patients (12.8% of women and 6.44% of men) had OKD. We recorded the complete drug prescription in 269 patientes. Mean of all different drugs that were prescribed by patient-year was 10.69±5.92 (men 9.55±5.57 and women 11.11±6; P=.05)]. A large number of patients were treated with potentially dangerous drugs, particularly the non-steroidal anti-inflammatory drugs with 165 cases (61.34%), and 72% were exposed to drugs that can lead to hyperkalaemia. Conclusions We conclude that GFR estimation by clinical laboratories in the setting of primary care can contribute to prevent the adverse effects of inappropriate drug prescriptions.

Occult chronic kidney disease: discordance among different methods used to estimate glomerular filtration rate in a healthy population

Chronic kidney disease is a widely recognized cardiovascular risk factor. Its detection within large populations depends upon the method used to estimate glomerular filtration. The Cockcroft and MDRD equations are widely used, although their accuracy is limited in certain cases. The present study analyzes glomerular filtration values in 674 young, healthy subjects using five methods: Cockcroft, Cockcroft corrected for body surface, MDRD-4 Lund-Malmö and Sawyer formulas. Glomerular filtration values obtained with the first three methods were compared using ANOVA. The Spearman coefficient was calculated to estimate the correlation between MDRD-4 and Cockcroft values, and between Cockcroft values and body mass index. There was a slight glomerular filtration rate decrease (< 90 ml/min) seen in 394 subjects using the Cockcroft equation, and in 344 subjects using the MDRD-4 formula. The prevalence of chronic kidney disease (glomerular filtration < 60 ml/min) was seen in 3 subjects using the MDRD-4 equation and 161 subjects using the Cockcroft formula. There was significant discordance, by method, between values obtained, with 40% of the population being classified into different stages (> 90 or < 90 ml/min) depending on the formula used. In 8% of the population there was even greater discordance, because they had strictly normal renal function according to MDRD-4 (> 90 ml/min) but fell into chronic kidney disease Stage 3 (< 60 ml/min) according to the Cockcroft formula. There was poor correlation between glomerular filtration rates obtained using the Cockcroft and MDRD-4 equations, suggesting that the subjects with a glomerular filtration rate decrease detected by the two methods were not the same ones. There was correlation between body mass index and glomerular filtration rates obtained with Cockcroft, Cockcroft corrected for body surface and Sawyer formulas and not with MDRD and Lund-Malmö equations. There are important discrepancies between the methods used to assess renal function in healthy populations. These limitations must be taken into account when deciding on strategies for diagnosis and control of occult chronic kidney disease in the general population.

¿Cómo realizar la búsqueda de enfermedad renal en pacientes con enfermedad cardiovascular?

Patients with chronic kidney disease are at high risk of cardiovascular disease and should receive intensive risk-reduction therapy. Early detection of albuminuria and chronic kidney disease can identify individuals at increased risk of adverse clinical events and therefore may have a better opportunity to improve their outcomes. The determination of serum creatinine should not be the only parameter used to as renal function. The evaluation of the renal involvement in patients with cardiovascular disease should be done using the determination of albumin in a urine spot test and estimating glomerular filtration from predictive equations derived from creatinine. The MDRD equation is of choice but alternatively the Cockcroft-Gault formula can also be used.

An easy to calculate equation to estimate GFR based on inulin clearance

For the estimation of renal function on the basis of serum creatinine, either the Cockcroft-Gault (CG) equation or the MDRD formula is commonly used. Compared to MDRD (using power functions), CG has the advantage of easy calculability at the bedside. MDRD, however, approaches glomerular filtration rate (GFR) more precisely than CG and gives values corrected for a body surface area (BSA) of 1.73 m(2). We wondered whether CG could be adapted to estimate GFR rather than creatinine clearance without losing the advantage of easy calculability. In this prospective study, inulin clearance under well-defined conditions was taken as the gold standard for GFR. In 182 living kidney donors, inulin clearance was measured under standardized conditions (protein, salt and water intake, overnight stay) before and after nephrectomy. Together with the serum creatinine level, and demographic and clinical data, 281 measurements of inulin clearance were used to compare the accuracy of different estimation equations. Using stepwise multiple regression, a new set of constants was defined for a CG-like equation in order to estimate GFR. The MDRD equation underestimated GFR by 9%, and the quadratic equation suggested by Rule overestimated GFR by 12.4%. The new CG-like equation, even when calculated with 'mental arithmetic-friendly' rounded parameters, showed significantly less bias (1.2%). The adapted equation is GFR[mL/min] = ((155 - Age[years]) x weight [kg]/serum creatinine [micromol/L]) x 0.85 if female. We propose the CG-like equation called IB-eGFR (Inulinclearance Based eGFR) to estimate GFR more reliably than MDRD, Rule's equation or the original Cockcroft-Gault equation. As our data represent a Caucasian population, the adapted equation is still to be validated for patients of other ethnicity.

A comparison of observed versus estimated baseline creatinine for determination of RIFLE class in patients with acute kidney injury

The RIFLE classification scheme for acute kidney injury (AKI) is based on relative changes in serum creatinine (SCr) and on urine output. The SCr criteria, therefore, require a pre-morbid baseline value. When unknown, current recommendations are to estimate a baseline SCr by the MDRD equation. However, the MDRD approach assumes a glomerular filtration rate of approximately 75 mL/min/1.73 m(2). This method has not been validated. Data from the Beginning and Ending Supportive Therapy for the Kidney (BEST Kidney) study, a prospective observational study from 54 ICUs in 23 countries of critically ill patients with severe AKI, were analysed. The RIFLE class was determined by using observed (o) pre-morbid and estimated (e) baseline SCr values. Agreement was evaluated by correlation coefficients and Bland-Altman plots. Sensitivity analysis by chronic kidney disease (CKD) status was performed. Seventy-six percent of patients (n = 1327) had a pre-morbid baseline SCr, and 1314 had complete data for evaluation. Forty-six percent had CKD. The median (IQR) values were 97 micromol/L (79-150) for oSCr and 88 micromol/L (71-97) for eSCr. The oSCr and eSCr determined at ICU admission and at study enrolment showed only a modest correlation (r = 0.49, r = 0.39). At ICU admission and study enrolment, eSCr misclassified 18.8% and 11.7% of patients as having AKI compared with oSCr. Exclusion of CKD patients improved the correlation between oSCr and eSCr at ICU admission and study enrolment (r = 0.90, r = 0.84) resulting in 6.6% and 4.0% being misclassified, respectively. While limited, estimating baseline SCr by the MDRD equation when pre-morbid SCr is unavailable would appear to perform reasonably well for determining the RIFLE categories only if and when pre-morbid GFR was near normal. However, in patients with suspected CKD, the use of MDRD to estimate baseline SCr overestimates the incidence of AKI and should not likely be used. Improved methods to estimate baseline SCr are needed.

The MDRD Equation Predicts Peritoneal Dialysis-Delivered Creatinine Clearances from Serum Creatinine

The four- and six-variable Modified Diet in Renal Disease equations (MDRDEs) are empiric expressions that estimate GFR in patients with kidney disease. No method currently exists to directly compare MDRDE estimates of clearance by the failing biologic kidney to the clearances achieved by dialytic modalities. Because the MDRDEs estimate GFR, which in turn determines much of the small molecule clearance by the biologic kidney, the aim of this study was to determine if the MDRDEs would predict the measured creatinine clearances (including residual renal clearance, if any) from the serum creatinine values alone in 454 peritoneal dialysis patients. For the group, the four-variable MDRDE predicted a creatinine clearance of 6.5 +/- 3.7 ml/min/1.73 m(2) when measured clearance was from home collections of dialysate and urine was 6.8 +/- 3.1 ml/min/1.73 m(2). The presence or volume of residual urine had no effect on accuracy. The six-variable MDRDE was similarly accurate. Creatinine appearance rates were similar to those reported in other dialysis populations. Using serum creatinine values in "standard" fashion, MDRDEs can approximate creatinine clearances achieved by peritoneal dialysis with an accuracy similar to that of the MDRDEs in predialysis populations, perhaps because the MRDREs account exponentially for the increasing fractional gut metabolism of daily creatinine production as the serum creatinine increases. "MDRD-like" equations may provide a much needed method of directly comparing dialytic clearances to those achieved by diseased native kidneys and by kidney transplants.

Prevalence of chronic kidney disease: a systematic review and meta-analysis

Many studies have estimated the prevalence of chronic kidney disease (CKD) but results have varied due partly to the type of equation used to estimate GFR, type of subjects, and ethnicity. This review aimed to estimate the prevalence of CKD Stage III, accounting for these factors. 403 studies were identified from Medline using the PubMed search engine, of which 34 studies were eligible. Data were independently extracted by two reviewers, and heterogeneity was assessed using metaregression. The pooled prevalence was estimated using a random effects model. In the general population, the prevalences of CKD Stage III using MDRD equation were 3.6% (95% CI: 2.5, 4.8), 10.7% (95% CI: 4.5 - 16.9%), and 16.3% (95% CI: 2.1 - 30.5%) for age groups 60 years. The prevalence was about double using the Cockcroft-Gault equations, i.e. 7.5% (95% CI: 6.9 - 8.2%) and 34.9 (95% CI: 25.9 - 44.8%) in age 50 years, respectively. The prevalence was similar in Caucasians and Asians aged. < or = 60, i.e. 9.9 versus 9.3%. The prevalence was also higher in the diabetic population than in the general population, i.e. 18.2% versus 10.6%. The pooled prevalence of CKD in the general population varied according to age groups. The prevalence is similar in Caucasians and Asians within age 60 years or younger but other age groups need more studies in order to pool. Individual patient meta-analysis would be appropriate to resolve the causes of heterogeneity.

Glomerular filtration rate and serum phosphate: an inverse relationship diluted by age

Available data indicate that serum phosphate increases only when glomerular filtration rate (GFR) falls into the low range (<60 mL/min x 1.73 m(2)). GFR and serum phosphate decrease with ageing. This population-based study investigated by age-controlled analyses the relationship of GFR with serum phosphate in adults with GFR above the low range. Data were collected on age, sex, menstrual status, anthropometry, overnight urinary creatinine, dietary protein (overnight urinary urea), reported intake of milk/yogurt, serum creatinine, phosphate, calcium and total protein in 4034 adults (age 18-91 years) with GFR >or=60 mL/min x 1.73 m(2) as assessed by estimated GFR (eGFR, simplified MDRD equation) and creatinine clearance (overnight urinary creatinine/serum creatinine). The relationship of eGFR with serum phosphate was positive in men and null in women in univariate analyses (P = 0.001 and 0.148), negative in both sexes with age adjustment (P < 0.001). Age-adjusted results did not depend on colinearity between age and eGFR because the relationship was inverse also replacing eGFR with creatinine clearance (P < 0.001 in both sexes). In univariate regression analysis done separately by gender and six age-strata (18-24, 25-34, 35-44, 45-54, 55-64 and >or=65), the line of serum phosphate over eGFR was constantly inverse (range of P = 0.010/0.089) with the progressively lower y-axis intercept from young to older ages. The inverse relationship of eGFR or creatinine clearance with serum phosphate was significantly inverse also controlling for other variables (P < 0.01). GFR differences in the range >or=60 mL/min x 1.73 m(2) are inversely and independently related to serum phosphate. The relationship is undetectable without age-controlled procedures because, for serum phosphate, the effect of GFR differences above >or=60 mL/min x 1.73 m(2) is much smaller than the effect of age.

Community-based study on CKD subjects and the associated risk factors.

Background. The study was performed to investigate the prevalence, awareness and the risk factors of chronic kidney disease (CKD) in the community population in Shanghai, China.Methods. A total of 2596 residents were randomly recruited from the community population in Shanghai, China. All were screened for albuminuria, haematuria, morning spot urine albumin-to-creatinine ratio and renal function. Serum creatinine, uric acid, cholesterol, triglyceride and haemoglobin were assessed. A simplified MDRD equation was used to estimate the glomerular filtration rate (eGFR). All studied subjects were screened by kidney ultrasound. Haematuria, if present in the morning spot urine dipstick test, was confirmed by microscopy. The associations among the demographic characteristics, health characteristics and indicators of kidney damage were examined.Results. Two thousand five hundred and fifty-four residents (n = 2554), after giving informed consent and with complete data, were entered into this study. Albuminuria and haematuria were detected in 6.3% and 1.2% of all the studied subjects, respectively, whereas decreased kidney function was found in 5.8% of all studied subjects. Approximately 11.8% of subjects had at least one indicator of kidney damage. The rate of awareness of CKD was 8.2%. The logistic regression model showed that age, central obesity, hypertension, diabetes, anaemia, hyperuricaemia and nephrolithiasis each contributed to the development of CKD.Conclusion. This is the first Shanghai community-based epidemiological study data on Chinese CKD patients. The prevalence of CKD in the community population in Shanghai is 11.8%, and the rate of awareness of CKD is 8.2%. All the factors including age, central obesity, hypertension, diabetes, anaemia, hyperuricaemia and nephrolithiasis are positively correlated with the development of CKD in our studied subjects.

The MDRD equation may mask decline of glomerular filtration rate in Fabry patients with normal or nearly normal kidney function

The renal prognosis in Fabry disease is better when enzyme replacement therapy (ERT) is initiated before glomerular filtration rate (GFR) deteriorates. Current studies evaluating kidney function in Fabry disease are mainly based on the MDRD equation. The aim of this cross sectional study was to compare estimated and measured GFR in adult Fabry patients with normal or near normal kidney function. Iohexol GFR (mGFR) was compared to estimated GFR (eGFR) (MDRD, Cockcroft-Gault and Counahan-Barratt equations) in 8 male and 13 female Fabry patients with minimal albuminuria and mean mGFR of 94 ml/min/1.73 m2 for both genders. A significant overestimation of eGFR-MDRD by 24 ml/min/1.73 m2 was seen in male Fabry patients. The performance of the MDRD equation was similar to mGFR in female Fabry patients. GFR was significantly overestimated by the Cockcroft-Gault equation, whilst Counahan-Barratt equation gave results in agreement with mGFR for both male and female Fabry patients. Overestimation of eGFR-MDRD in Fabry patients with CKD stage 1 - 2 and minimal albuminuria may prevent recognition of early progressive renal failure and delayed ERT initiation may be the consequence. Exact GFR markers should be part of the routine evaluation of GFR in Fabry patients.

High Prevalence of Intracranial Artery Calcification in Stroke Patients with CKD

Intracranial artery calcification (IAC) is frequently observed on brain computed tomography (CT) scans in stroke patients. This retrospective study was designed to determine the prevalence, risk factors, and clinical relevance of IAC in a cohort of patients with ischemic stroke. We included all eligible patients admitted to Amiens University Hospital for acute ischemic stroke between January and December 2006 and assessed using 64-slice multidetector-row CT (n = 340). Patients were classified according to the presence or absence of IAC in the internal carotid arteries, middle cerebral arteries, vertebral arteries, and basilar artery. GFR was estimated using the MDRD equation. Chronic kidney disease (CKD) was defined as a GFR < 60 ml/min/1.73 m(2). We also studied a control group of patients admitted for neurologic diseases other than stroke. Two hundred fifty-nine stroke patients (76.2%) displayed IAC, which was independently associated with carotid atherosclerosis > 50%, age, and GFR. One hundred three nonstroke patients (60.2%) had IAC, with age, arterial hypertension, and GFR as independently associated factors. For all patients taken together, age, arterial hypertension, stroke, and GFR were independently associated with IAC. These results confirm the high prevalence of IAC in patients with and without ischemic stroke and show for the first time that IAC is associated with the presence of CKD in these patients. The frequency of IAC was significantly higher in stroke patients than in nonstroke patients. The association between IAC and stroke outcome requires further investigation.

Tumor Exposure and Cold Ischemia Using a LapSac® in Partial Nephrectomy by Video-Assisted Minilaparotomy Surgery (VAMS)

Purpose: We report a new method of tumor exposure through a minilaparotomy window and cold ischemia using a LapSacR during partial nephrectomy by video-assisted minilaparotomy surgery (VAMS). Materials and Methods: Partial nephrectomy was performed by VAMS in a total of 31 patients during a period ranging from January 2004 to June 2006, and tumor exposure and cold ischemia were achieved by using a LapSacR. We investigated the tumor size and location, mean operative time, mean estimated blood loss, mean cold ischemic time, and pathologic outcomes retrospectively. We evaluated preoperative and postoperative renal function with the estimated creatinine clearance rate by the MDRD equation. Results: The mean tumor size was 2.59±1.30 cm and mean surgical time was 182.5±44.5 minutes. Mean cold ischemic time was 31.84±8.43 minutes. Mean estimated blood loss was 445.65±202.77 ml (range, 100-800 ml), and 3 patients required transfusion. A histopathologic examination confirmed a diagnosis of renal cell carcinoma in 22 patients (71%). The surgical margin was positive in 1 patient. Twenty-one patients had a mean followup of 53±8.19 months. Nineteen patients survived without any disease recurrence, 1 patient survived with lung metastasis within 5 months, and 1 patient died of unrelated cause. There was no significant difference between the preoperative and postoperative estimated creatinine clearance rate by using the MDRD equation. Conclusions: Tumor exposure and cold ischemia were attempted in a partial resection of the kidney by VAMS with a LapSacR. This technique for partial nephrectomy by VAMS might be an effective, safe modality. (Korean J Urol 2009;50:774-779) 󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏

Serum cystatin C: A useful marker of kidney function in very old people

Background: Serum creatinine-based estimates of GFR may be inaccurate in the elderly and there is need for improvement. Serum Cystatin C, not being influenced by muscle volume, may be more accurate. Material and methods: GFR was measured with plasma clearance of iohexol in 50 elderly persons aged >70 years. Blood tests were drawn for analysis of creatinine, albumin and urea. Cystatin C was analysed on frozen specimens using the Dade Behring method. GFR estimates based on cystatin C were compared to estimates based on serum creatinine, using earlier published equations. Results: Significant increase with age was found with cystatin C (rs=0.62, p<0.0001) and urea (rs=0.43, p=0.0018) but no correlation with creatinine (rs=0.05, p=0.7502). All equations underestimated GFR with a bias ranging from −2.2 to −31%. The equation with the greatest accuracy was the Hoek equation (Cystatin C based) with 98% of estimates within 30% of mGFR and confidence interval 89–100%. Estimated GFR using the MDRD Study equations (creatinine based) showed accuracy of 94% with 4 or 6 factors used. There was a gender difference with an accuracy higher among males (p<0.002). The Cockcroft Gault equation was not found useful with high bias and a low accuracy. Conclusion: S-cystatin C seems a useful marker for kidney function in the elderly. Two equations based on serum cystatin C as well as the two MDRD equations seem adequate for estimating kidney function.