Performance of the race-free CKD-EPI creatinine-based eGFR equation in a Danish cohort with measured GFR

Age- and sex-specific reference values of estimated glomerular filtration rate for European adults

Kidney function, often assessed by estimated glomerular filtration rate (eGFR), declines naturally with age. However, there is a lack of eGFR reference values to describe normal and abnormal values for a specific age. The European Chronic Kidney Disease Burden Consortium is comprised of nine participating general population-based studies from seven European countries which provides European age- and sex-specific eGFR reference values in healthy adults using the European Kidney Function Consortium (EKFC) equation. Of 2,572,020 individuals, 1,535,253 (60%) were considered healthy, of which 45% were men. Ages ranged from 18 to 105 years old in men and 18 to 107 years old in women with a median age of 43 years in both sexes. At age 20 in men, the 5th, 50th and 95th eGFR percentiles were 78 ml/min per 1.73 m2, 99 ml/min per 1.73 m2, and 119 ml/min per 1.73 m2. In 20-year-old women this was 81 ml/min per 1.73 m2, 101 ml/min per 1.73 m2, and 121 ml/min per 1.73 m2. Consequently, in men aged 80 years old, the 5th, 50th and 95th eGFR percentiles were 49 ml/min per 1.73 m2, 66 ml/min per 1.73 m2, and 84 ml/min per 1.73 m2. In 80 year old women this was 46 ml/min per 1.73 m2, 63 ml/min per 1.73 m2, and 81 ml/min per 1.73 m2. Overall, our study shows that eGFR is not preserved with ageing in healthy individuals and these eGFR reference values can help determine abnormal and normal kidney function across the age range.

Association Between Chronic Kidney Disease Risk Categories and Abdominal Aortic Calcification: Insights From the National Health and Nutrition Examination Survey

BACKGROUND

Abdominal aortic calcification (AAC) is a critical indicator of cardiovascular risk, particularly in patients with chronic kidney disease (CKD). Traditional classification systems may underestimate the risk in those with moderate CKD. This study aimed to evaluate the association between CKD risk categories - defined by both estimated glomerular filtration rate (eGFR) and albuminuria - and the prevalence of severe AAC.

METHODS

This cross-sectional study analyzed data from the National Health and Nutrition Examination Survey (NHANES) 2013-2014. We included adults aged ≥ 40 years who underwent imaging for AAC assessment, excluding pregnant individuals and those without AAC scores. Survey-weighted and multivariate logistic regression was employed to assess the relationship between CKD risk categories and severe AAC, adjusting for age, hypertension, and smoking history. Subgroup analyses were conducted to explore variability across demographic and clinical subgroups.

RESULTS

We analyzed data from 3,140 participants in the NHANES, 423 (13.4%) of whom had severe AAC. The cohort was categorized into CKD risk categories 1 through 4, with the majority (76%) in stage 1. Severe AAC was more prevalent among older individuals and those with traditional cardiovascular risk factors. Initial unadjusted analyses revealed that CKD category 2 was associated with a nearly fourfold increase in severe AAC (odds ratio (OR): 3.93), while categories 3 and 4 showed 3.75-fold and over 10-fold increases, respectively (all P < 0.01). However, after adjusting for confounders, categories 2 and 4 showed higher risks of severe AAC compared to category 1, but these associations did not reach statistical significance (OR: 1.72, 95% confidence interval (CI): 0.90 - 1.86, P = 0.06 and OR: 5.70, 95% CI: 0.85 - 38.00, P = 0.07, respectively).

CONCLUSION

Our study offers insights that may complement the current reliance on eGFR and albuminuria in risk stratification, highlighting that CKD category 2, defined by mildly reduced eGFR and albuminuria, may be a potential marker for severe AAC. Although statistical significance was narrowly missed after full adjustment, the clinical implications remain significant, advocating for more aggressive cardiovascular risk management in this population. This understanding may contribute to evolving approaches in CKD-related cardiovascular risk assessment and inform potential intervention strategies.

Impact of the 2021 CKD-EPI equation on anticancer pharmacotherapy in black and non-black cancer patients

Cancer and kidney disease disproportionately impact Black patients. The CKD-EPI2021 equation was developed to estimate glomerular filtration rate (eGFR) without using race. We assessed the impact of using CKD-EPI2021 instead of CKD-EPI2009 or Cockcroft-Gault (CG) on dosing and eligibility of anticancer drugs in Black and non-Black patients. Utilizing the National Cancer Institute Theradex database, deindexed eGFR (mL/min) was calculated for 3931 patients (8.6 % Black) using CKD-EPI2021, CKD-EPI2009, and CG. Dosing simulations based on each eGFR were performed for ten anticancer drugs with kidney function-based eligibility or dosing cutoffs. eGFR differences using CKD-EPI2021 versus CKD-EPI2009 varied between Black and non-Black patients (p < 0.001); on average, Black patients had 10.3 mL/min lower eGFR and non-Black patients had 4.2 mL/min higher eGFR using CKD-EPI2021. This corresponded to a difference in relative odds of cisplatin ineligibility using CKD-EPI2021 versus CKD-EPI2009; Black patients had 48 % higher odds of ineligibility and non-Black patients had 27 % lower odds of ineligibility using CKD-EPI2021 (p < 0.001). When using CKD-EPI2021 versus CG, eGFR differences were similar between Black and non-Black patients (p = 0.679) and relative difference in odds of cisplatin ineligibility did not vary. Using CKD-EPI2021 versus CKD-EPI2009 differentially impacts Black versus non-Black cancer patients; Black patients have lower calculated eGFR and are less likely to receive full doses of drug using CKD-EPI2021. From the historical default of CG, adopting CKD-EPI2021 would not disparately impact patients based on race, but would result in Black patients being less likely to receive full doses of drug than if CKD-EPI2009 were used.

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.