Modification Of Diet In Renal Disease Research Articles

DIFFERENTIAL PREVALENCE AND ASSOCIATIONS OF CHRONIC KIDNEY DISEASE BY FIVE ESTIMATORS IN A SOUTH AFRICAN POPULATION-BASED STUDY

Objective: The aim was to determine the prevalence, distribution, concordance and associations of chronic kidney disease (CKD) assessed by five glomerular filtration rate (GFR) formulae in urban black residents of Cape Town. Design and method: In this population-based cross-sectional study, stratified for age and gender, data collection included administered questionnaires, clinical measurements and biochemical analyses, including serum creatinine and cystatin C levels. GFR was based on the CKD Epidemiology Collaboration (CKD-EPI) equations (CKD-EPI creatinine (CKD-EPIcr), CKD-EPI cystatin C (CKD-EPIcys), CKD-EPI creatinine-cystatins (CKD-EPIcr-cys)), Modification of Diet in Renal Disease (MDRD) and Cockcroft-Gault formula (CGF). GFR <60 mL/min/1.73 m2 defined CKD. Results: Mean estimated GFR, among 392 men and 700 women, was between 114.0 (CKD-EPIcr) and 135.4 mL/min/1.73 m2 (CGF) in men, and between 107.5 (CKD-EPIcr-cys) and 173.4 mL/min/1.73 m2 (CGF) in women. CKD prevalence ranged from 2.3% (CKD-EPIcr and MDRD) to 5.1% (CKD-EPIcys) in men and 1.6% (CGF) to 6.7% (CKD-EPIcr-cys) in women. Correlations between different estimates of GFR were positive and significant, and there were no significant differences between any two coefficients. The kappa statistic was high between CKD-EPIcr and MDRD (0.934), and CKD-EPIcys and CKD-EPIcr-cys (0.815), but fair-to-moderate between the other equations (0.353–0.565). In the basic regressions, older age and body mass index >30 kg/m2, but not gender, were significantly associated with CKD-EPIcr-defined CKD. In the presence of these three variables, but in separate models, hypertension, heart rate >90 beats/minute, diabetes and increasing low-density lipoprotein cholesterol were significant predictors of prevalent CKD by CKD-EPIcr and MDRD (except for diabetes). Metabolic syndrome, in the model with age and gender only, was significantly associated with CKD-EPIcr- and MDRD-defined CKD. No cardio-metabolic variable was associated with CKD determined by CKD-EPIcys, CKD-EPIcr-cys or CGF. Conclusions: The varying CKD prevalence estimates, on account of different GFR equations used, underscores the need to improve accuracy of CKD diagnoses. Moreover, considering the significant associations of cardio-metabolic diseases with CKD-EPIcr- and MDRD-defined CKD, screening for CKD should be incorporated into the routine assessment of high-risk patients such as those with hypertension or diabetes.

RELATIONSHIP BETWEEN ARTERIAL STIFFNESS AND RENAL FUNCTION DETERMINED BY CKD-EPI AND MDRD EQUATIONS IN A CHINESE COHORT UNDERGOING HEALTH ASSESSMENT

Objective: The relationship between the renal function and large arteries remains to be determined. Our study investigated the relationship between carotid-femoral pulse wave velocity (c-fPWV) as a measure of arterial stiffness and renal function in healthy participants. Design and method: Our cross-sectional study was conducted in healthy individuals in China. We enrolled participants from January 2017 to June 2019. c-fPWV and blood pressure were measured and blood samples taken in all participants. Estimated glomerular filtration rate (eGFR) was evaluated by four different formulae using Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and Modification of Diet in Renal Disease (MDRD) equations: (i) CKD-EPICr formula based on Cr, (ii) CKD-EPICysC formula based on CysC, (iii) CKD-EPICrCysC formula based on Cr andCysC, (iv) MDRD. Results: Average age of 431 study participants was 53.1 ± 13.0 years (68.1% male), 23.7% had diabetes mellitus, 66.6% had hypertension. The average eGFR values of CKD-EPICr, CKD-EPICysC, CKD-EPICrCysC and MDRD equations were respectively 91.9 ± 15.6, 86.8 ± 21.4, 89.6 ± 18.3 and 90.7 ± 16.6 ml/min·1.73m2. c-fPWV was significantly and negatively correlated with eGFR of CKD-EPICr (r = -0.336), CKD-EPICysC (r-0.385), CKD-EPICrcysC (r = -0.378) and MDRD (r = 0.219) equations. After adjusting for confounding factors, c-fPWV remained significantly and negatively correlated with eGFR evaluated by CKD-EPICysC equation (β=-0.118), and significantly and positively correlated with age (β = 0.347), SBP (β= 0.275), HR (β = 0.086), FPG (β= 0.098). Conclusions: In normal individuals in China, c-fPWV is negatively correlated with eGFR evaluated in different four equations, however only the equation of CKD-EPICysC showed an independent relation with c-fPWV.

THE RELATIONSHIP BETWEEN ATRIAL FIBRILLATION AND RENAL DYSFUNCTION

Objective: Lately, interrelation between atrial fibrillation (AF) and chronic kidney disease (CKD) has received increasing attention, owing to the collective risk factors. The aim of this study, was to appreciate the severity of the renal dysfunction depending on the temporal pattern of atrial fibrillation in patients presenting both conditions. Design and method: We retrospectively analyzed 258 atrial fibrillation patients, mean age 73.48 yr (SD= 10.4), 51.6% females, presenting different stages of chronic kidney disease. The study population was divided in three groups based on the presentation and duration of AF: paroxysmal, persistent and permanent. In order to quantify the severeness of the CKD, we estimated the glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease (MDRD) equation. Results: Related to the type of atrial fibrillation, 38% of patients had paroxysmal AF, 3.9% persistent AF, respectively 58.1% had permanent AF. Regarding the mean value of the eGFR, in the paroxysmal AF group we obtained a mean value of 69.06 ml/min/1.73 (median= 67.5, SD= 33.54) while in the persistent AF group the mean eGFR value was 70.9 ml/min/1.73 (median= 67.5, SD= 31.2) and in the group of permanent AF, the mean value was 61.2 ml/min/1.73 (median= 55.5, SD= 30.26). Therefore, no statistically significant difference (p = 0.6262) was obtained in terms of the severity of renal dysfunction compared to the type of atrial fibrillation. Conclusions: Our findings demonstrate that neither type of AF is predisposing to more severe outcome of chronic kidney disease. On the other hand, independent of atrial fibrillation type, the eGFR is an important monitoring tool of CKD progression in atrial fibrillation patients. Overall, due to increasingly occurrence of atrial fibrillation with chronic kidney disease, further studies are required in order to streamline their management, taking into account renal function in determining cardioembolic risk as well.

RENAL HISTOPATHOLOGICAL PROFILE IN PATIENTS WITH SILENT LUPUS NEPHRITIS

Background: Silent lupus nephritis (SLN) is a life menacing consequence of systemic lupus erythematous (SLE). This condition is characterized by pathological impairment of the kidney in the obscurity of clinical or laboratory manifestations. Objective: To reveal the existence of SLN along with the potential differences between overt lupus nephritis (OLN) and SLN among a sample of Egyptian patients based on histopathological assessment. Patients and Methods: It is a prospective case-control study which was performed at nephrology units, internal medicine department, Elhussein and Sayed Galal university hospitals, faculty of medicine, Al-Azhar University, Cairo, Egypt, throughout the entire period April 2016 to November 2019. Patients aged more than 18 years (216 months) and fulfilled at least 4 of the American College of Rheumatology criteria for the classification of systemic lupus erythematosus (SLE) were enrolled in the current study. Patients were further assorted into two groups; patients with SLN and those with OLN. Patients were subjected to the following investigations: 1.Complete blood count, using Coulter counter Max-M (Coulter Cooperation, Florida, USA) 2.Erythrocyte sedimentation rate, (Wester green method) (Ref: < 20mm/hr) 3.S. Albumin, S. Creatinine. Albumin/Creatinine ratio. Creatinine clearanc & eGFR using the Modification of Diet in Renal Disease (MDRD) formula. 4. Liver function tests. 5. Coagulation profile. 6. Urine analysis (Fresh morning midstream urine) to exclude infection. 7. Quantitative assessment of proteinuria by Pr/creat. Ratio (Ref. <0.2). Assessment of auto-antibodies and complement system: Autoantibodies to ds-DNA, RNP. SSA, SSB, Sm and Scl-70, C4 and C3 serum levels were assessed in all of the included patients. In particular, the titer of anti-dsDNA antibodies was evaluated by enzyme- Radiological evaluation: Patients were subjected to pelvi-abdominal ultrasound in order to obtain valuable data about the morphological appearance of the kidney and to detect any urological abnormality. Renal biopsy: Percutaneous renal biopsy was carried out under local anesthesia. Results: An overall 40 patients with SLE who developed lupus nephritis were enrolled in the current study. Among them, 20 patients had OLN, whereas 20 patients were SLN. Based on ISN/RPS Classification, stage II was the predominant stage, 13 patients, among patients with SLN, whilst stage V was the predominant stage among the OLN patients. Additionally, five and three patients were stage III among the SLN and OLN groups, respectively. Furthermore, the presence of RBCs Cast (r=0.479, P=0.032) in urine and decreased levels of complement (r=0.676, P=0.001) showed a statistically significant positive correlation with the high grades of lupus nephritis among SLN group. Conclusion: Patients with SLE should be subjected to close follow up evaluation and renal biopsy for early detection of SLN to determine the activity, severity, and chronicity of LN.

IMPACT OF CHRONIC KIDNEY DISEASE ON HEART FAILURE SEVERITY IN HYPERTENSION AND ATRIAL FIBRILLATION PATIENTS

Objective: Given the frequent association of chronic kidney disease (CKD) to cardiovascular disorders and the coexistence of heart failure (HF) with atrial fibrillation (AF), especially in elderly, hypertension being a contributor, our main objective was to assess the effect of kidney dysfunction on the heart failure progression in hypertension and atrial fibrillation patients. Design and method: We conducted a retrospective analytic-observational study that included 258 AF patients, mean age 73.48 yr (SD = 10.4), 51.6% females. In order to classify the CKD, we divided the study population in two groups based on the estimated glomerular filtration rate (eGFR): higher or equal than 60, respectively below 60 ml/min/1.73 square meters, comparing the estimations of Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. We used the NYHA classification to identify the HF severity. Results: Of all patients, according to the presence or absence of the hypertension, 210 patients (81.4%) presented high blood pressure values. In terms of the eGFR using the MDRD equation, 117 patients presented a value higher or equal than 60 ml/min/1.73 square meters, while 93 had an eGFR below 60 ml/min/1.73 square meters. The median value of NYHA class was 3 in both groups (SD = 1.03; 0.96) and there was no statistical significance (p = 0.13) between them. By comparison, estimation using the CKD-EPI equation, indicated a statistically significant difference (p = 0.03), 109 patients presented higher than 60 ml/min/1.73 square meters and 101 patients were below this cut off value even though the median NYHA class was 3 as well (SD = 1.04; 0.94). Conclusions: These results reinforce the well-known superiority in the accuracy of the CKD-EPI equation. But, in terms of the influence of renal dysfunction severity on the heart failure severeness, our results suggest that decreasing in the eGFR is not correlated with the progression of the heart failure in AF patients. However, given the severity of complications and importance of proper treatment in atrial fibrillation, the development of an estimation equation that relates to the presence of atrial fibrillation should be considered.

Raising the (LVAD) Bar: Temporary RVAD Support and its Effects on Renal Function

Purpose Right heart failure (RHF) is a crucial risk factor in the development of acute kidney injury. By decreasing the right-ventricular filling pressures and increasing cardiac output, right ventricular assist devices (RVAD) may prevent the development of cardiorenal syndrome. We report our institutional experience on the development of renal function and outcome after left ventricular assist device (LVAD) and temporary RVAD implantation in congestive heart failure patients. Methods We retrospectively reviewed the data of 72 consecutive patients who received a continuous-flow LVAD and temporary RVAD due to terminal heart failure at our center from 12/ 2001 and 12/ 2019. Mean age of patient population was 58 ± 12 years, with 86.1% of the patients being male. Sixty-three patients (87.5%) were able to be successfully weaned from temporary RVAD support. However, two patients (2.8%) required an RVAD to be re-implanted due to progressive RHF. Median time of temporary RVAD support was 13 days (4 - 90 days). Renal function was determined by the Modification of Diet in Renal Disease (MDRD)-derived glomerular filtration rates (GFR), and patients were categorized into two groups based on pre-implant GFR: (1) normal renal function, defined by GFR > 60 (n=29), and (2) impaired renal function, defined by GFR Results The patient group with impaired renal function (RF) experienced a significant improvement of GFR: GFR at time of implant to month six, 41.94 ± 11.37 to 65.21± 39.52 (p=0.003), and after one-year GFR improved from 41.94 ± 11.37 to 55.73 ± 23.22 (p=0.012). Post-implant renal replacement therapy was indicated in eighteen patients (41.86%) of the impaired RF group vs. ten patients (34.48%) in the normal RF group. Post-implant survival after LVAD and temporary RVAD support at one, six, and 12 months for GFR 60 group, 89.7%, 72.4% and 72.4%, respectively (p=0.576). Conclusion LVAD and temporary RVAD support improves renal function in patients with renal dysfunction prior to implantation. Our data indicates that impaired renal function prior to implantation does not guarantee a worsened outcome.

Elderly Patients in a Large Nephrology Unit: Who Are Our Old, Old-Old and Oldest-Old Patients?

The world population is aging, and the prevalence of chronic kidney disease (CKD) is increasing. Whether this increase is also due to the methods currently being used to assess kidney function in the elderly is still a matter of discussion. We aimed to describe the actual referral pattern of CKD patients in a large nephrology unit and test whether the use of different formulae to estimate kidney function could affect the staging and the need for specialist care in the older subset of our population. In 2019, 1992 patients were referred to our center. Almost 28% of the patients were aged ≥80 and about 6% were ≥90 years old. Among the causes of kidney disease, glomerulonephritis displayed a higher prevalence in younger patients whereas hypertensive or diabetic kidney disease were more prevalent in older patients. The prevalence of referred patients in advanced CKD stages increased with age; estimated glomerular filtration rate (eGFR) decreased with age regardless of which equation was used (chronic kidney disease epidemiology collaboration (CKD-EPI), Lund–Malmö Revised (LMR), modification of diet in renal disease (MDRD), Full Age Spectrum (FAS), or Berlin Initiative Study 1 (BIS)). With CKD-EPI as a reference, MDRD and FAS underestimated the CKD stage while LMR overestimated it. The BIS showed the highest heterogeneity. Considering an eGFR threshold limit of 45 mL/min for defining “significant” CKD in patients over 65 years of age, the variability in CKD staging was 10% no matter which equation was used. Our study quantified the weight of “old” and “old-old” patients on follow-up in a large nephrology outpatient unit and suggested that with the current referral pattern, the type of formula used does not affect the need for CKD care within the context of a relatively late referral, particularly in elderly patients.

Pretransplant Use of the Chronic Kidney Disease Epidemiology Collaboration Equation (CKD-EPI) to Estimate Glomerular Filtration Rate Predicts Outcomes in Liver Transplant Recipients.

Kidney dysfunction is common in liver transplant candidates and is a well-established predictor of increased mortality after liver transplant. However, the best method for determination of the glomerular filtration rate before liver transplant remains unclear. We analyzed the performance of the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation and the Modification of Diet in Renal Disease (MDRD) Study equation, before liver transplant, compared with radionuclide glomerular filtration rate and examined the association of the 2 equations with a composite outcome of stage 4 chronic kidney disease, initiation of chronic dialysis, or patient death. We studied 426 consecutive adult liver transplant recipients from 1990 to 2014. The correlation coefficient of the radionuclide glomerular filtration rate with the Chronic Kidney Disease Epidemiology Collaboration equation was 0.61 and with the Modification of Diet in Renal Disease Study equation was 0.58. The Modification of Diet in Renal Disease Study equation showed a bias of -4.7 mL/min and precision of 32.9 mL/min, whereas the Chronic Kidney Disease Epidemiology Collaboration equation showed a bias of -11.1 mL/min but was more precise (28.1 mL/min). Only the Chronic Kidney Disease Epidemiology Collaboration equation remained significantly associated with the composite outcome in the multivariable analysis. The use of the Chronic Kidney Disease Epidemiology Collaboration equation in the period before liver transplant provided independent prognostic information regarding long-term outcomes after liver transplant.

CamGFR v2: A New Model for Estimating the Glomerular Filtration Rate from Standardized or Non-standardized Creatinine in Patients with Cancer.

Management of patients with cancer, specifically carboplatin dosing, requires accurate knowledge of glomerular filtration rate (GFR). Direct measurement of GFR is resource limited. Available models for estimated GFR (eGFR) are optimized for patients without cancer and either isotope dilution mass spectrometry (IDMS)- or non-IDMS-standardized creatinine measurements. We present an eGFR model for patients with cancer compatible with both creatinine measurement methods. GFR measurements, biometrics, and IDMS- or non-IDMS-standardized creatinine values were collected for adult patients from three cancer centers. Using statistical modeling, an IDMS and non-IDMS creatinine-compatible eGFR model (CamGFR v2) was developed. Its performance was compared with that of the existing models Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), Modification of Diet in Renal Disease (MDRD), Full Age Spectrum (FAS), Lund-Malmö revised, and CamGFR v1, using statistics for bias, precision, accuracy, and clinical robustness. A total of 3,083 IDMS- and 4,612 non-IDMS-standardized creatinine measurements were obtained from 7,240 patients. IDMS-standardized creatinine values were lower than non-IDMS-standardized values in within-center comparisons (13.8% lower in Cambridge; P < 0.0001 and 19.3% lower in Manchester; P < 0.0001), and more consistent between centers. CamGFR v2 was the most accurate [root-mean-squared error for IDMS, 14.97 mL/minute (95% confidence interval, 13.84-16.13) and non-IDMS, 15.74 mL/minute (14.86-16.63)], most clinically robust [proportion with >20% error of calculated carboplatin dose for IDMS, 0.12 (0.09-0.14) and non-IDMS, 0.17 (0.15-0.2)], and least biased [median residual for IDMS, 0.73 mL/minute (-0.68 to 2.2) and non-IDMS, -0.43 mL/minute (-1.48 to 0.91)] eGFR model, particularly when eGFR was larger than 60 ml/minute. CamGFR v2 can utilize IDMS- and non-IDMS-standardized creatinine measurements and outperforms previous models. CamGFR v2 should be examined prospectively as a practice-changing standard of care for eGFR-based carboplatin dosing.

The paradoxical relationship between severity of cerebral palsy and renal function in middle-aged adults: better renal function or inappropriate clinical assessment?

Purpose To determine the association between severity of cerebral palsy with serum creatinine (sCr) and sCr-based equations to estimate glomerular filtration rate (eGFR), a marker of renal function. Methods A clinic-based sample of 30–64 year-olds with cerebral palsy was examined and stratified by motor impairment: gross motor function classification system (GMFCS) I/II (n = 79), GMFCS III (n = 78), and GMFCS IV/V (n = 137). sCr, which is influenced by muscle mass, was obtained and sCr-based eGFR was calculated using the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. Results sCr was lower with increasing GMFCS. The opposite pattern was observed for eGFR: GMFCS IV/V had significantly higher eGFR derived from MDRD compared to other GMFCS groups; GMFCS III had significantly higher eGFR compared to GMFCS I/II. The pattern was similar for CKD-EPI derived eGFR. Conclusions According to widely used clinical assessment methods for renal function, higher severity of cerebral palsy among adults is associated with better renal function, which is incongruent with their other biological systems. This paradoxical relationship is likely driven by lower muscle rather than true renal function, and thus, sCr-based eGFR may overestimate renal function, especially for GMFCS IV/V. Further prospective studies are needed. Implications for rehabilitation Common methods of clinical assessment may over-estimate renal function for adults with cerebral palsy (CP), potentially giving a false positive for normal renal health due to their reliance on muscle mass. This study of a clinic-based sample of middle-aged adults with CP highlights the paradoxical relationship between severity of CP and renal function, which is likely driven by methodological limitations in the presence of low muscle mass rather than actual better renal function. It is recommended that clinicians have a high suspicion of abnormal renal function and the need for a nephrology consultation, especially with changes in creatinine levels, even within the normal range. Rehabilitation for adults with CP must have a strong focus on muscle and kidney health, especially for patients with more severe forms of CP.

Associations between air pollutant exposure and renal function: A prospective study of older adults without chronic kidney disease.

We used real-world exposure scenarios to evaluate the effect of six ambient air pollutant (PM2.5, PM10, NO2, SO2, CO, and O3) exposure on renal function among older adults without chronic kidney disease (CKD). We recruited 169 older adults without CKD in Beijing, China, for a longitudinal study from 2016 to 2018. The Modification of Diet in Renal Disease (MDRD) and the Chronic Kidney Disease Epidemiology Collaboration (EPI) equations were employed to derive the estimated glomerular filtration rate (eGFR). A linear mixed-effects model with random intercepts for participants was employed to determine the effects of air pollutants on renal function evaluated on the basis of eGFR and urinary albumin/creatinine ratio at different exposure windows (1-, 2-, 3-, 5-, 7-, 14-, 28-, 45-, and 60-days moving averages). An interquartile range (IQR) increase in NO2 for was associated with significant decreases of in eGFR (MDRD equation) [percentage changes: -4.49 (95% confidence interval: -8.44,-0.37),-5.51 (-10.43,-0.33),-2.26 (-4.38,-0.08),-3.71 (-6.67,-0.65),-5.44 (-9.58,-1.11),-5.50 (-10.24,-0.51),-6.15 (-10.73,-1.33), and-6.34 (-11.17,-1.25) for 1-, 2-, 5-, 7-, 14-, 28-, 45-, and 60-days moving averages, respectively] and in eGFR (EPI equation) [percentage changes: -5.04 (-7.09,-2.94),-6.25 (-8.81,-3.62),-5.16 (-7.34,-2.92),-5.10 (-7.85,-2.28),-5.83 (-8.23,-3.36),-6.04 (-8.55,-3.47) for 1-, 2-, 14-, 28-, 45-, and 60-days moving averages, respectively]. In two-pollutant model, only the association of NO2 exposure with eGFR remained robust after adjustment for any other pollutant. This association was stronger for individuals with hypertension for the EPI equation or BMI <25kg/m2 for the MDRD equation at lags 1 and 1-2. Our findings suggest that NO2 exposure is associated with eGFR reduction among older adults without CKD for short (1-, 2-days) and medium (14-, 28-, 45-, 60-days) term exposure periods; thus, NO2 exposure may contribute to renal impairment.

Prevalence and associated factors of impaired renal function and albuminuria among adult patients admitted to a hospital in Northeast Ethiopia.

Chronic kidney disease (CKD) is increasingly common in hospitalized patients and is associated with increased risk for in-hospital morbidity and mortality. However, data regarding the prevalence of CKD in the African hospitalized patient population are limited. We therefore examined the prevalence and associated factors of impaired renal function and albuminuria among adult patients admitted to the internal medicine wards of a hospital in Northeast Ethiopia. A cross-sectional study was conducted from January 1 to April 30, 2020 at the inpatient settings of Dessie referral hospital. Data on demographics and medical history were obtained, and serum creatinine and albuminuria were analyzed. Estimated glomerular filtration rate (eGFR) was calculated using the Modification of Diet in Renal Disease (MDRD) equation. CKD was defined as impaired eGFR (<60 ml/min/1.73m2) and/or albuminuria. Univariate and multivariable analysis were conducted to determine factors associated with impaired eGFR and albuminuria. A total of 369 patients were included in this study. The prevalence of impaired eGFR was 19.0% (95%CI: 15.2%-23.2%) and albuminuria was 30.9% (95%CI: 26.3%-35.7%). Overall, 33.9% (95%CI: 29.2%-38.9%) of the patients had some degree of CKD, but only 21.6% (95%CI: 15.1%-29.4%) were aware of their renal disease. In multivariable analysis, older age, a family history of kidney disease, diabetes, hypertension and HIV were independently associated with both impaired eGFR and albuminuria while male gender was independently associated with only albuminuria. CKD is common in adult patients admitted to the internal medicine wards, but only few patients are aware of their condition. These findings highlight the need for feasible approaches to timely identify kidney disease and raise awareness on the importance of detection and early intervention in the inpatient settings.

Clinical implications of the estimated glomerular filtration rate

A correct determination of the glomerular filtration rate (GFR) is necessary and at the same time difficult. Using gold standard methods, such as measurement of inulin clearance, are not feasible in clinical practice raising the need for methods to estimate GFR using easy to measure endogenous biomarkers. Plasma concentrations of the filtration markers creatinine and cystatin C alone are not adequate to easily calculate kidney function. This is mainly due to anon-linear relationship between plasma concentrations and GFR and GFR-independent factors influencing the plasma concentrations. Therefore, formulae have been developed to estimate GFR using easily available variables. Currently, the most useful formulae are those developed by the modification of diet in renal disease (MDRD) study and more recently by the chronic kidney disease epidemiology (CKD-EPI) collaboration. For older individuals some specifically validated formulae were developed some years ago, among them the Berlin initiative study 1 (BIS-1) and BIS‑2 formulae. The accuracy of the estimated filtration rate (eGFR) with respect to the true GFR depends on various factors. The accuracy of the formula is especially low in the GFR range above 60 ml/min · 1.73 m2, during recent or rapid changes of GFR and in the case of extreme physical traits, especially a very high or low muscle mass. In older individuals an eGFR around 60 ml/min · 1.73 m2 alone is not sufficient to discriminate between age-related and disease-related decline in GFR. Nonetheless dosing of medications with predominantly renal excretion should be made according to the eGFR.

Effect of Endoscopic Ureteral Stone Treatment on Kidney Function

Introduction: Ureteral stones may have an influence on kidney functions due to postrenal obstruction or urinary infections. Urgent decompression or stone removal is necessary and recommended to prevent further complications in case of severe conditions such as anuria and urosepsis. Although it is believed that ureteral stone removal would result in renal function improvement, there are still unclear points on whether ureteroscopy (URS) can provide benefit as expected and has some adverse effects.In this study, we aimed to evaluate the alteration of kidney functions of patients who undergo rigid or flexible URS for ureteral stones and find if there are any influencing factors on kidney function alteration.Materials and Method: We analyzed 126 patients who underwent retrograde intrarenal surgery (RIRS) for renal stones between May 2018 and February 2020 prospectively. The estimated glomerular filtration rate (eGFR) was calculated on the day before the surgery, by modification of diet in renal disease (MDRD) formula. The calculation was repeated and saved three times during follow-up for the same patient; on the day after the operation, on the postoperative 30th day, and the postoperative 90th day. Then, we evaluated the renal function by comparing eGFR and assessed the predicting factors affecting the kidney function.Results: Preoperative mean eGFR was 82.28 ± 25.20 mL/min/1.73 m2 for the study group. Mean eGFR was calculated 90.92 ± 22.97 mL/min/1.73 m2 on the first postoperative day, and 94.54 ± 21.95 mL/min/1.73 m2 on the third-month follow-up. The mean change in eGFR was 8.63 ± 16.68 mL/min/1.73 m2 in the early period and 12.26 ± 21.09 mL/min/1.73 m2 in the long-term follow-up period. Fifty-one patients improved on chronic kidney disease (CKD) stage, and 13 deteriorated in three months follow-up.Conclusion: Removing the stone and relieving the obstruction by ureteroscopic treatment have an alteration on eGFR. Although eGFR improves in the short-term follow-up, amelioration is evident in long-term follow-up, especially in female patients. The other predictive factors for eGFR improvement after URS are the presence of ureteral obstruction and high preoperative serum creatinine levels.

Predictive Value of N-Terminal Prohormone of Brain Natriuretic Peptide in Long-Term Remodeling of the Left Ventricle in Diabetic Patients of Young and Middle Age With Acute Coronary Syndrome After Percutaneous Coronary Intervention

Abstract. Recently, quantitative analysis of the level of the N-terminal prohormone of the brain naturetic peptide (NT-proBNP) has been widely used to diagnose heart failure (HF). A statistically significant correlation was found between the serum NT-proBNP concentration and HF stage. It was found that in patients with high cardiovascular risk, NT-proBNP has the highest predictive value in relation to mortality. In young and middle-aged patients with diabetes mellitus (DM) with myocardial infarction (MI) and stents of an infarct-associated artery, the frequency of unfavorable remodeling (UR) of the left ventricle (LV) in the long-term prognosis was studied. The frequency of atherosclerotic lesions of the coronary arteries (CA) in patients with diabetes in acute coronary syndrome (ACS) was determined, the results of echocardiographic parameters were presented in the follow-up dynamics, the value of serum NT-proBNP in predicting LV UR 12 months after myocardial infarction (MI) was determined.Aim of study. To assess the diagnostic capabilities of NT-proBNP in the long-term prediction of the development of LV infarction in patients with MI with diabetes in young and middle age after percutaneous coronary intervention (PCI).Design. Prospective controlled non-randomized trial. The patients were examined twice: on the first day of ACS after PCI with stenting of infarct-associated coronary artery and 12 months after AMI. The study included 191 patients with ACS with / without ST-segment elevation, who were divided into two groups. The main group included 76 patients with ACS with diabetes mellitus, the comparison group included 115 patients with ACS without diabetes mellitus. Patients in both groups were comparable in age, gender, comorbidity, and complications of AMI. The duration of diabetes was, on average, 6 years (from one to 12 years).Material and methods. All patients underwent electrocardiography, echocardiography, tests for the content of troponin I, NT-proBNP, glycosylated hemoglobin, lipids, determined the level of creatinine in the blood and the glomerular filtration rate according to the Modification of diet in renal disease (MDRD). All patients were examined twice: on the first day of ACS after PCI with stenting of infarct-associated coronary artery and 12 months later.Results. In 69% of diabetic patients with anterior myocardial infarction and in 63% of patients with posterolateral MI 12 months after PCI, signs of LV inferiority were revealed in the form of an increase in the indices of end-diastolic and systolic volumes of the LV and low ejection fraction (≤45%). In patients without diabetes, these figures were 18% and 31%, respectively. High concentrations of NT-proBNP on the first day of myocardial infarction after PCI were of the greatest value in the diagnosis and prognosis of LV UR after 12 months.Conclusion. The NT-proBNP level of more than 776 pg/ml on the first day after PCI is an indicator of an unfavorable long-term prognosis in patients with young and middle-aged diabetes in terms of the development of LV systolic dysfunction.

Renal function in a cohort of HIV-infected patients initiating antiretroviral therapy in an outpatient setting in Ethiopia.

To evaluate the prevalence and associated factors of abnormal renal function among Ethiopian HIV-infected patients at baseline prior to initiation of antiretroviral therapy (ART) and during follow-up. We conducted a retrospective observational cohort study of HIV infected patients who initiated ART at the outpatient ART clinic of Mehal Meda Hospital of North Shewa, Ethiopia from January 2012 to August 2018. Demographic and clinical data were abstracted from the medical records of patients. Renal function was assessed by estimated glomerular filtration rate (eGFR) calculated using the Modification of Diet in Renal Disease (MDRD) equation. Univariate and multivariate analysis were conducted to determine the factors associated with abnormal renal function at baseline and during follow-up. Among 353 patients, 70 (19.8%) had baseline eGFR <60 ml/min/1.73m2 and 102 (28.9%) had eGFR = 60-89.9 ml/min/1.73m2. Factors associated with baseline renal impairment (eGFR <60 ml/min/1.73m2) included female sex (AOR = 3.52, CI 1.75-7.09), CD4 count < 200 cells/mm3 (AOR = 2.75, CI 1.40-5.42), BMI < 25 Kg/m2 (AOR = 3.04, CI 1.15-8.92), low hemoglobin (AOR = 2.19, CI 1.16-4.09) and high total cholesterol (AOR = 3.15, CI 1.68-5.92). After a median of 3.0 years of ART, the mean eGFR declined from 112.9 ± 81.2 ml/min/1.73m2 at baseline to 93.9 ± 60.6 ml/min/1.73m2 (P < 0.001). The prevalence of renal impairment increased from 19.8% at baseline to 22.1% during follow-up. Of 181 patients with baseline normal renal function, 49.7% experienced some degree of renal impairment. Older age (AOR = 3.85, 95% CI 2.03-7.31), female sex (AOR = 4.18, 95% CI 2.08-8.40), low baseline CD4 (AOR = 2.41, 95% CI 1.24-4.69), low current CD4 count (AOR = 2.32, 95% CI 1.15-4.68), high BMI (AOR = 2.91, 95% CI 1.49-5.71), and low hemoglobin (AOR = 3.38, 95% CI 2.00-7.46) were the factors associated with renal impairment during follow-up. Impaired renal function was common in HIV-infected patients initiating ART in an outpatient setting in Ethiopia, and there appears to be a high prevalence of renal impairment after a median ART follow-up of 3 years. There is a need for assessment of renal function at baseline before ART initiation and regular monitoring of renal function for patients with HIV during follow-up.

An Evaluation of Commonly Used Surrogate Baseline Creatinine Values to Classify AKI During Acute Infection

IntroductionClassification of acute kidney injury (AKI) requires a premorbid baseline creatinine, often unavailable in studies in acute infection.MethodsWe evaluated commonly used surrogate and imputed baseline creatinine values against a “reference” creatinine measured during follow-up in an adult clinical trial cohort. Known AKI incidence (Kidney Disease: Improving Global Outcomes [KDIGO] criteria) was compared with AKI incidence classified by (1) back-calculation using the Modification of Diet in Renal Disease (MDRD) equation with and without a Chinese ethnicity correction coefficient; (2) back-calculation using the Chronic Kidney Disease–Epidemiology Collaboration (CKD-EPI) equation; (3) assigning glomerular filtration rate (GFR) from age and sex-standardized reference tables; and (4) lowest measured creatinine during admission. Back-calculated distributions were performed using GFRs of 75 and 100 ml/min.ResultsAll equations using an assumed GFR of 75 ml/min underestimated AKI incidence by more than 50%. Back-calculation with CKD-EPI and GFR of 100 ml/min most accurately predicted AKI but misclassified all AKI stages and had low levels of agreement with true AKI diagnoses. Back-calculation using MDRD and assumed GFR of 100 ml/min, age and sex-reference GFR values adjusted for good health, and lowest creatinine during admission performed similarly, best predicting AKI incidence (area under the receiver operating characteristic curves [AUC ROCs] of 0.85, 0.87, and 0.85, respectively). MDRD back-calculation using a cohort mean GFR showed low total error (22%) and an AUC ROC of 0.85.ConclusionCurrent methods for estimating baseline creatinine are large sources of potential error in acute infection studies. Preferred alternatives include MDRD equation back-calculation with a population mean GFR, age- and sex-specific GFR values corrected for “good health,” or lowest measured creatinine. Studies using surrogate baseline creatinine values should report specific methodology.

Comparison of various predictive equations for glomerular filtration rate in healthy individuals and chronic kidney disease patients from North India.

A noninvasive and accurate estimate of the glomerular filtration rate (GFR) is an essential prerequisite for medical professionals. In the absence of 24-h urinary creatinine clearance, various predictive equations can be utilized for estimating GFR. A cross-sectional observational study was conducted on healthy adults as well as adult chronic kidney disease (CKD) Indian population. In normal males and females, Modification of Diet in Renal Disease-4 (MDRD-4) and Cockcroft- Gault (CG) were the best equations respectively, which showed the best correlation and best precision in CKD stage 1 males and females, MDRD-4 and MDRD-6 were the best equations respectively In CKD stage 2 males and females, CKD-Epidemiology Collaboration (CKD-EPI) was adjudged the best equation, which showed the best correlation, best precision, and least bias. In CKD stage 3 males and females, CG and CKD-EPI were the best equation respectively, with the best correlation, best precision, least biased, and most accuracy. In CKD stage 4 males and females, MDRD-6 and MDRD-4 showed the best correlation, best precision and most accuracy respectively. In CKD stage 5, CKD-EPI demonstrated the best results in both sexes. We observed that all the predictive equations were good estimates of GFR in one or other stages of CKD, but no single predictive equation showed consistent results when compared among normal subjects and CKD sub-groups.

Chronic kidney diseases among homeless and slum dwellers in Accra, Ghana.

Introductionchronic kidney disease is an important risk factor for cardiovascular-related morbidity and death. In Ghana, relatively little is known about the prevalence of chronic kidney disease (CKD) in homeless and slum dwellers in the major cities of the country. This study aimed at determining the prevalence of CKD among homeless people in Nima and Agbogbloshie, Accra, Ghana, and to evaluate the association between socio demographic characteristics and CKD.Methodswe recorded information on individuals' socio-demographic characteristics and anthropometric indices, and took blood samples from a total of 512 homeless participants for serum creatinine measurement. Renal function was estimated according to the 4-variable Modification of Diet in Renal Disease (MDRD) and Cockcroft–Gault (C-G) equations.Resultsparticipants with normal serum creatinine (SCr), made up of 232 males and 280 females totaling 512 took part in the study. Those with normal glomerular filtration rate (GFR) were 86% and 84.6% by means of the C-G and MDRD equations respectively. According to the C-G formula, kidney damage and mild to severe renal insufficiency was found in 13.2% of the participants and 4 participants (0.8%) had renal failure. On the other hand, 15.4% of the participants were found to have some kidney damage and mild to severe renal insufficiency according to the MDRD formula with no participant suffering from kidney failure.Conclusionthe prevalence of CKD among the homeless Ghanaians was significant, especially among those with hypertension, diabetes and human immunodeficiency syndrome virus (HIV) infection.

Estimation of Glomerular Filtration Rate and Predicting Diagnostic Accuracy of Cystatin C and Creatinine in Detection of Renal Function among Longstanding Type-2 Diabetics

Introduction: Estimation of Glomerular Filtration Rate (GFR) is dependent on Serum Creatinine (SCr). Though, a sudden decrease in GFR would not result in rapid rise in concentrations of SCr, as they are imprecise but it leads to the over diagnosis of Chronic Kidney Disease (CKD). Aim: To calculate GFR using Cystatin-C (Cys-C) based formulas to contrast its accuracy with SCr based formulas and to predict the diagnostic accuracy of Cys-C in patients with diabetes. Materials and Methods: A total 48 type-2 diabetic patients were diagnosed with CKD and their GFR was assessed using the Cys-C and SCr. GFR was measured and estimated using three equations (Cockcroft-Gault (CG), Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CDK-EPI), that are based on SCr and three equations (LeBricon, Grubb and Hoek) based on Cys-C among the 48 CKD patients. The filtration rate was measured using labelled diethylenetriaminepentaacetic acid (99mTc-DTPA) renal scan method as the standard for comparison. The Receiver Operating Characteristics (ROC) analysis was used to evaluate the diagnostic accuracy of the filtration rate. Results: A significant association was observed (p=0.0001) among both the estimates which were equivocal when compared with measured iGFR, SCr and Cys-C based GFR estimate. A greater difference of Area Under the Curve (AUC) was observed between SCr (0.765±0.07) and Cys-C (0.569±0.09) (p=0.04) in the ROC analysis at a creatinine clearance &lt;60 mL/min/m2. conclusion: The SCr and Cys-C based formulae has equivocal performance in estimating GFR. SCr could be a better marker to estimate GFR among patients with Cr clearance &lt;60 mL/min/m2.