A reliable assessment of renal function is of paramount importance in several clinical assets in order to tailor a personalized medical approach. CKD classification system, created in 2002 by the National Kidney Foundation-sponsored Kidney Disease Outcomes Quality Initiative and then implemented in the following years by the K-DIGO guidelines, offered clinicians a new strategy to better identify nephrological patients at low or high risk to develop renal insufficiency, in order to avoid the progression to end-stage renal disease. However, the criteria used to create this classification did not consider some important aspects related to renal histology and glomerular filtration rate measurement, resulting in a possible over- or underestimation of the real established renal damage. In this mini-review, we will summarize the most relevant shortcomings in the CKD classifications, which can create misleading diagnosis in daily clinical practice.

Canagliflozin reduces the risk for cardiovascular and kidney outcomes in type 2 diabetes. This study aimed to assess the relative and absolute effects of canagliflozin on clinical outcomes across different KDIGO (Kidney Disease: Improving Global Outcomes) risk categories based on estimated glomerular filtration rate (eGFR) and urinary albumin-creatinine ratio.
Post hoc analysis of the CANagliflozin cardioVascular Assessment Study (CANVAS) Program.
The CANVAS Program randomly assigned 10,142 participants with type 2 diabetes at high cardiovascular risk and with eGFR≥30mL/min/1.73m2 to treatment with canagliflozin or placebo.
Canagliflozin or matching placebo.
The primary outcome was a composite of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke, with a set of other cardiovascular and kidney prespecified outcomes.
Of 10,142 participants, 10,031 (98.9%) had available baseline eGFR and urinary albumin-creatinine ratio data. The proportion of participants in low-, moderate-, high-, and very high-risk KDIGO categories was 58.6%, 25.8%, 10.6%, and 5.0%, respectively. The relative effect of canagliflozin on the primary outcome (HR, 0.86; 95% CI, 0.75-0.97) was consistent across KDIGO risk categories (P trend=0.2), with similar results for other cardiovascular and kidney outcomes. Absolute reductions in the primary outcome were greater within higher KDIGO risk categories (P trend=0.03) with a similar pattern of effect for the composite of cardiovascular death or hospitalization for heart failure (P trend=0.06) and for chronic eGFR slope (P trend = 0.04).
Predominantly a low kidney risk population, relatively few participants in higher KDIGO risk categories, and exclusion of individuals with eGFR<30mL/min/1.73m2.
Although the relative effects of canagliflozin are similar across KDIGO risk categories, absolute risk reductions are likely greater for individuals at higher KDIGO risk. The KDIGO classification system may be able to identify individuals who might derive greater benefits for end-organ protection from treatment with canagliflozin.
This post hoc analysis was not specifically funded. The original CANVAS Program trials were funded by Janssen Research & Development, LLC and were conducted as a collaboration between the funder, an academic steering committee, and an academic research organization, George Clinical.
The original trials of the CANVAS Program were registered at ClinicalTrials.gov with study numbers NCT01032629 and NCT01989754.

Atrial fibrillation (AF) and chronic kidney disease (CKD) are known risk factors for each other. In Tama City in Tokyo, 12-lead ECG and serum creatinine concentration have been included as essential examinations in specific health checkups to diagnose AF and CKD. In the present study, we investigated the impact of CKD classification on new-onset AF in the general population.Methods and Results:Among 13,478 subjects aged 40-74 years at entry (age, 65.6±7.8 years; men, 42.0%), renal impairment with estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2and proteinuria were found in 15.5% and 4.6%, respectively. CKD severity in individual subjects was classified according to a heatmap of the Japanese Society of Nephrology as 81.3% in the green, 15.1% in the yellow, 2.5% in the orange, and 0.9% in the red. Of those without AF in 2012, it had developed in 115 up to 2017; thus, the new-onset AF incidence rate was 2.6/1,000 person-years. Hazard ratios and 95% confidence intervals for new-onset AF in each CKD classification were 1.50 (0.93-2.41, P=0.097) in the yellow, 2.53 (1.03-6.23, P=0.044) in the orange, and 4.65 (1.47-14.70, P=0.009) in the red compared with the green as a reference.
CKD classification was significantly associated with new-onset AF in the general population. Thus, it would be useful for risk stratification of new-onset AF. Renal function evaluation is recommended in health checkups.