Accuracy and precision of the CKD-EPI and MDRD predictive equations compared with glomerular filtration rate measured by inulin clearance in a Saudi population

Performance of Modification of Diet in Renal Disease and Chronic Kidney Disease Epidemiology Collaboration Equations Versus 99Tc-DTPA-Renogram in Assessing Kidney Function

Objectives

To evaluate the performance of measurement of glomerular filtration rate (GFR) using Modification of Diet in Renal Disease equations (MDRD186, MDRD175) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations, in comparison with technetium-99m diethylenetriaminepentaacetic acid (99Tc-DTPA) renogram method, the gold standard. A related aim was to correlate the three equations to estimate GFR and their impact on reclassifying the stages of CKD in adult Omani patients.

Methods

This cross-sectional study recruited two groups of patients diagnosed with CKD during a 10-month period from January to October 2021. The first group comprised 48 patients who underwent a 99Tc-DTPA renogram procedure for GFR measurement, and the second group comprised 30 348 adult patients who did not undergo the same procedure; estimated GFR was calculated using the three equations.

Results

The median of the reference GFR was 106.0 mL/min/1.73 m2, whereas the median estimated GFR for the MDRD175, MDRD186, and CKD-EPI equations were 92.5, 98.3, and 102.1, respectively. All three equations correlated moderately with the reference GFR (0.428, 0.428, 0.523, respectively; p < 0.010). The CKD-EPI showed lesser bias (3.7 vs. 12.9 and 7.5 for MDRD175 and MDRD186, respectively) and more accuracy (95.8% vs. 91.7% and 93.8%); however, it was the least precise (25.1 vs. 22.3 and 23.8). The MDRD186 performed similarly to the CKD-EPI equation at CKD stages 3a-5 and differed significantly at stages 1-2. Whereas the MDRD175 differed significantly with both equations at stages 1-3b and was similar to them at stages 4-5.

Conclusions

The CKD-EPI equation had the highest accuracy and the least bias and precision in the general population. The MDRD186 CKD classification differed significantly from the CKD-EPI equation at CKD-stages 1-2 only. The CKD-EPI equation is preferred to MDRD for the detection and classification of early CKD stages.

Comparison of Three Glomerular Filtration Rate Estimating Equations with 24-Hour Urine Creatinine Clearance Measurement in Potential Living Kidney Donors

Background

The accuracy of the measurement of renal function in potential living kidney donors (PLKD) is essential. The direct measurement of glomerular filtration rate (mGFR) has been considered the "gold standard." The estimated GFR (eGFR) with 24-hour urinary creatinine clearance (CrCl) is frequently used because of its availability. We aim to evaluate the correlation and agreement of eGFR using serum-based creatinine formulas (Cockcroft-Gault, MDRD, and CKD-EPI) and the eGFR based on 24-hour urinary CrCl to evaluate kidney function in PLKD.

Methods

We evaluated the kidney function in 799 PLKD using 24-hour urinary CrCl method and compared the correlation and agreement with the eGFR based on creatinine formulas (Cockcroft-Gault, MDRD, and CKD-EPI). We calculated the mean bias (difference), precision (SD of this difference), accuracy, and performed Bland-Altman plots.

Results

A total of 799 PLKD were analyzed. The age of the PLKD ranged from 18 to 73 years. Weak to mild correlation was observed between 24-hour urinary CrCl and all formulas (ranged from 0.31 to 0.49). The three equations underestimated the GFR. Using the Bland-Altman graphic, we observed that the CKD-EPI was the least scattered and most precise; however, mean bias and the interval range (limits of agreement) of all formulas were too big to assume equivalence between 24-hour urinary CrCl method and eGFR based on creatinine. Results of mean bias were similar when comparing the three equations in patients with CrCl GFR <60. However, the accuracy of all formulas was better for the female group and the youngest individuals (≤40 years old).

Conclusion

In this PLKD cohort, of all the three equations, the CKD-EPI was the least scattered and most precise. However, the correlation and the level of agreement between the three equations and 24-hour urinary CrCl were too low to assume the equivalence.

Plasma Trimethylamine N-Oxide Levels Are Associated with Poor Kidney Function in People with Type 2 Diabetes

Previous studies have linked elevated plasma trimethylamine N-oxide (TMAO) levels to poor renal function. The relationship between TMAO and chronic kidney disease (CKD) in type 2 diabetes (T2D) is still unclear. We investigated the association between plasma TMAO levels and CKD in patients with T2D. A cross-sectional study of 133 patients with T2D with or without CKD has been conducted. Blood biomarkers of kidney function, diabetes, and inflammation were assessed in the study participants. Plasma TMAO levels were quantified using UPLC-MS/MS. People with T2D and CKD exhibited significantly higher plasma TMAO levels [10.16 (5.86-17.45) µmol/L] than those without CKD [4.69 (2.62-7.76) µmol/L] (p = 0.002). Participants in the highest quartile of TMAO levels (>8.38 µmol/L) presented relatively elevated serum creatinine levels and a higher number of people with CKD than those in the lower quartiles. TMAO levels were significantly correlated with kidney function biomarkers, including estimated glomerular filtration rate and urinary albumin to creatinine ratio. The association between TMAO and CKD was evident (p < 0.0001) and remained significant after adjusting for risk factors of kidney disease, including age, gender, body mass index, duration of diabetes, and smoking. These findings suggest the association between plasma TMAO and CKD in patients with T2D.

Determinants of prolonged hospitalization and mortality among leptospirosis patients attending tertiary care hospitals in northeastern state in peninsular Malaysia: A cross sectional retrospective analysis

Background

Leptospirosis is the most common anthropozoonosis worldwide and imposes a major public health problem in many tropical countries. It is a leading cause of disease burden in form of mortality, morbidity and hospital admission. Identifying patients at high risk for mortality or for prolonged hospitalization may save lives and preserve economy. The aim of the current study is to identify significant factors associated with disease mortality and prolonged hospitalization.

Design

Cress-sectional retrospective study.

Settings

Tertiary care teaching hospitals in Kelantan, Peninsular Malaysia.

Participants

Adult patients proven to have leptospirosis depending on IgM ELISA were classified into two classes depending on prolonged hospitalization (&gt;7 days or ≤ 7 days) and mortality (fatal cases or non-fatal cases). Patients' clinico-laboratory data were compared according to these two outcomes using the appropriate statistical test.

Results

Of the 525 patients enrolled, 136 (25.9%) had prolonged hospitalization. The mean length of stay was 6.77 ± 5.68 days. Logistic regression analysis identified acute kidney injury (AKI) (OR 2.3), Jaundice (OR 2.7), elevated alanine aminotransferase (ALT) (OR 2), and prolonged prothrombin time (PT) (OR 1.9) independently associated with prolonged hospitalization. Case fatality rate was 6.48% and around one third of fatal cases had prolonged hospitalization of more than seven days. Factors associated with leptospirosis mortality included age &gt;40 years (p &lt; 0.001), patients presented with tachypnea (p = 0.002), pulmonary infiltrate (p &lt; 0.001), T-wave changes (p &lt; 0.001), atrial fibrillation (p = 0.013), conducting abnormality (p &lt; 0.001), chronic kidney diseases (p &lt; 0.001), multiple organ dysfunctions (p &lt; 0.0010), respiratory failure (p &lt; 0.001), pneumonia (p &lt; 0.001), sepsis (p = 0.004), low venous PH (p = 0.042), AKI (P &lt; 0.001), elevated AST (p &lt; 0.001) or ALT (p = 0.004), hypoalbuminemia (p &lt; 0.001), rhabdomyolysis (p &lt; 0.001), severe thrombocytopenia (p = 0.042), prolonged PT (p &lt; 0.001) or prolonged aPTT (p &lt; 0.017).

Conclusions

Significant proportion of leptospirosis patients (25.9%) had prolonged hospital stay and less proportion died (6.48%). Early identifying patients with factors associated with prolonged hospitalization and death will positively impact practitioners' decisions regarding the proper and fast course of management including ICU admission.

Urine headspace analysis with field asymmetric ion mobility spectrometry for detection of chronic kidney disease

Electronic noses (eNoses) are an emerging class of experimental diagnostic tools. They are based on the detection of volatile organic compounds. Urine is used as sample medium in several publications but neither the effect of chronic kidney disease (CKD) on the analysis nor the potential to detect CKD has been explored. Materials & methods: We utilized an eNose based on field asymmetric ion mobility spectrometry (FAIMS) technology to classify urine samples from CKD patients and controls. Results: We were able to differentiate extremes of kidney function with an accuracy of 81.4%. Conclusion: In this preliminary study, applying eNose technology we were able to distinguish the patients with impaired kidney function from those with normal kidney function.

The practicality of different eGFR equations in centenarians and near-centenarians: which equation should we choose?

Background

No studies have examined the practicality of the Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiological Collaboration (CKD-EPI) and Berlin Initiative Study 1 (BIS1) equations for the estimated glomerular filtration rate (eGFR) in a large sample of centenarians. We aim to investigate the differences among the equations and suggest the most suitable equation for centenarians and near-centenarians.

Methods

A total of 966 centenarians and 787 near-centenarians were enrolled, and the eGFR was calculated using the three equations mentioned above. Agreement among the equations was investigated with the κ statistic and Bland-Altman plots. Sources of discrepancy were investigated using a partial correlation analysis.

Results

The three equations for assessing eGFR are not considered interchangeable in centenarians and near-centenarians. Δ(MDRD, CKD-EPI) and Δ(MDRD, BIS1) increased with age, but Δ(CKD-EPI, BIS1) was relatively stable with age. Δ(MDRD, CKD-EPI) and Δ(MDRD, BIS1) were considerable in subjects with Scr levels less than 0.7 mg/dL and decreased with the Scr level. A considerable difference between CKD-EPI and BIS1 was observed for participants with Scr levels ranging from 0.5 to 1.5 mg/dL. This difference increased with Scr levels ranging from 0.5 to 0.7 mg/dL, was relatively stable for Scr levels ranging from 0.7 to 0.9 mg/dL, and decreased with Scr levels ranging from 0.9 to 1.5 mg/dL. The differences in the three comparisons were all greater in women than in men (p < 0.05).

Conclusions

We tend to suggest the MDRD equation to calculate the glomerular filtration rate (GFR) in elderly individuals >95 years old who have no risk factors for cardiovascular disease; the BIS1 equation to calculate the eGFR for elderly individuals younger than 94 years old who have risk factors for cardiovascular disease; the CKD-EPI equation to calculate the eGFR of elderly individuals with Scr levels greater than 1.5 mg/dL; and the BIS1 equation to calculate the eGFR of older women with Scr levels less than 0.7 mg/dL.

Prognostic Comparison of the Estimations of Renal Function in Patients With Acute Heart Failure

BACKGROUND

The prognostic significance of the eGFR calculated by either the four-level Race Chronic Kidney Disease-Epidemiology Collaboration study equation (CKD-EPI4R) or the Chinese-modified Modification of Diet in Renal Disease equation (cMDRD) has not been compared in Asian populations with acute heart failure (AHF).Methods and Results:A total of 3,044 patients hospitalized for AHF were enrolled. The National Death Registry was linked to identify deaths within a 5-year follow-up. Net reclassification improvement (NRI) was calculated to compare the prognostic value of either eGFR equation. During a median follow-up of 23.3 months, 1,424 (47%) patients died. Both eGFR_cMDRDand eGFR_CKD-EPI4Rwere independently predictive of death in the total study population (hazard ratio and 95% confidence intervals per 1-SD: 0.76, 0.71-0.81 and 0.74, 0.70-0.79, respectively), and in the subgroups of either reduced (HFrEF) or preserved (HFpEF) ejection fraction, after accounting for important confounders. With reference to eGFR_cMDRD, eGFR_CKD-EPI4Rmay improve the NRI by 2.0% (0.8-3.2%) for the prediction of death. The prognostic value of the CKD stages categorized by eGFR_CKD-EPI4Rsignificantly outperformed eGFR_cMDRDwith a categorical NRI of 9.5% (4.7-14.3%) in the total study population, 11.5% in HFrEF, and 8.3% in HFpEF.

CONCLUSIONS

Both eGFR_cMDRDand eGFR_CKD-EPI4Rwere independently associated with long-term survival in patients with AHF. However, the CKD stages derived from eGFR_CKD-EPI4Rimproved the risk stratification of death, compared with eGFR_cMDRD.

A review of urinary angiotensin converting enzyme 2 in diabetes and diabetic nephropathy

Urinary angiotensin converting enzyme 2 (ACE2) is significantly increased in diabetes and diabetic nephropathy. While studies on its clinical significance are still underway, its urinary expression, association with metabolic and renal parameters has been in the recent past considerably studied. The recent studies have demystified urine ACE2 in many ways and suggested the roles it could play in the management of diabetic nephropathy. In all studies the expression of urinary ACE2 was determined by enzyme activity assay and/with the quantification of ACE2 protein and mRNA by methods whose reliability are yet to be evaluated. This review summarizes recent findings on expression of urinary ACE2, examines its relationship with clinical parameters and highlights possible applications in management of diabetic nephropathy.

Chronic kidney disease in the global adult HIV-infected population: A systematic review and meta-analysis

INTRODUCTION

The widespread use of antiretroviral therapies (ART) has increased life expectancy in HIV patients, predisposing them to chronic non-communicable diseases including Chronic Kidney Disease (CKD). We performed a systematic review and meta-analysis (PROSPERO registration number CRD42016036246) to determine the global and regional prevalence of CKD in HIV patients.

METHODS

We searched PubMed, Web of Science, EBSCO and AJOL for articles published between January 1982 and May 2016. CKD was defined as estimated glomerular filtration rate (eGFR) <60ml/min using the MDRD, Cockcroft-Gault or CKD-EPI equations. Random effects model was used to combine prevalence estimates from across studies after variance stabilization via Freeman-Tukey transformation.

RESULT

Sixty-one eligible articles (n = 209,078 HIV patients) in 60 countries were selected. The overall CKD prevalence was 6.4% (95%CI 5.2-7.7%) with MDRD, 4.8% (95%CI 2.9-7.1%) with CKD-EPI and 12.3% (95%CI 8.4-16.7%) with Cockcroft-Gault; p = 0.003 for difference across estimators. Sub-group analysis identified differences in prevalence by WHO region with Africa having the highest MDRD-based prevalence at 7.9% (95%CI 5.2-11.1%). Within Africa, the pooled MDRD-based prevalence was highest in West Africa [14.6% (95%CI 9.9-20.0%)] and lowest in Southern Africa (3.2%, 95%CI 3.0-3.4%). The heterogeneity observed could be explained by WHO region, comorbid hypertension and diabetes mellitus, but not by gender, hepatitis B or C coinfection, CD4 count or antiretroviral status.

CONCLUSION

CKD is common in HIV-infected people, particularly in Africa. HIV treatment programs need to intensify screening for CKD with added need to introduce global guidelines for CKD identification and treatment in HIV positive patients.