Kidney Week

Abstract: TH-PO390

Comparison of Standard and Age-Adapted GFR Criteria for Determination of CKD Prevalence

Session Information

• CKD: Risk Scores and Translational Epidemiology
  November 07, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

• 2101 CKD (Non-Dialysis): Epidemiology, Risk Factors, and Prevention

Authors

• Jonsson, Arnar Jan, Landspitali - The National University Hospital of Iceland, Reykjavík, Iceland

Arnar Jan Jonsson,

• Lund, Sigrún Helga, deCODE genetics, Reykjavík, Iceland

Sigrún Helga Lund,

• Palsson, Runolfur, Landspitali - The National University Hospital of Iceland, Reykjavík, Iceland

Runolfur Palsson,

• Indridason, Olafur S., Landspitali - The National University Hospital of Iceland, Reykjavík, Iceland

Olafur S. Indridason,

Background

Inclusion of age-adapted GFR criteria in the definition of chronic kidney disease (CKD) has been proposed to avoid overdiagnosis in the elderly and underdiagnosis in the young. The aim of this study was to estimate the prevalence of CKD based on age-adapted glomerular filtration rate (GFR) criteria compared with a standard cut-off GFR value of 60 mL/min/1.73 m².

Methods

In this retrospective study, we obtained all serum creatinine (SCr) values and urine protein measurements from every clinical laboratory in Iceland in 2008-2016. Clinical information, including ICD-10 diagnosis codes, was retrieved from nationwide electronic medical records. Estimated GFR was calculated from SCr using the CKD-EPI equation. CKD was defined as presence of kidney damage, either proteinuria or ICD-10 diagnosis codes indicating kidney disease, or reduced eGFR for ≥3 months. The definition of reduced eGFR was <60 mL/min/1.73 m² according to the standard KDIGO criteria, whereas the age-adapted eGFR definition was <75 mL/min/1.73 m² for age <40 years, <60 mL/min/1.73 m² for 40-65 years and <45 mL/min/1.73 m² for age ≥65 years.

Results

We obtained 2,120,232 SCr values for 218,437 individuals. The median age was 46 (range, 18-107) years; 47% were men. The age-adjusted mean annual prevalence of CKD per 100,000 men and women, respectively, was 4420 (95%CI, 4370-4470) and 5500 (95%CI, 5440-5550) using standard GFR criteria, compared with 2844 (95%CI, 2805-2883) and 3232 (95%CI, 3190-3274) using age-adapted criteria. In men, the prevalence per 100,000 using standard vs age-adapted GFR criteria was 505 vs 591 in the age group 18-44 and 54,454 vs 31,958 in the age group 85+. In women, the prevalence per 100,000 was 908 vs 1078 and 48,868 vs 26,157 for the same age groups, respectively (Figure 1).

Conclusion

Compared with the conventional GFR cut-off, age-adapted GFR thresholds for definition of CKD yield a slightly higher prevalence in the young age groups, but a markedly lower prevalence among older people.

Figure 1. Prevalence of CKD per 100,000 by sex (men black, women gray), age groups and diagnostic criteria.