Kidney Week

Abstract: TH-PO770

Mortality Risk According to eGFR and Proteinuria in Persons Older Than 65 Years: Results From a Nationwide Study in Iceland

Session Information

• Voices, Choices, and Outcomes of Older Adults with CKD
  November 03, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
  Abstract Time: 10:00 AM - 12:00 PM

Category: Geriatric Nephrology

• 1200 Geriatric Nephrology

Authors

• Jonsson, Arnar Jan, Landspitali–The National University Hospital of Iceland, Reykjavik, Iceland

Arnar Jan Jonsson,

• Lund, Sigrún Helga, deCODE Genetics Inc, Reykjavik, Capital, Iceland

Sigrún Helga Lund,

• Eriksen, Bjorn Odvar, University Hospital of North Norway, Tromso, Norway

Bjorn Odvar Eriksen,

• Palsson, Runolfur, Landspitali–The National University Hospital of Iceland, Reykjavik, Iceland

Runolfur Palsson,

• Indridason, Olafur S., Landspitali–The National University Hospital of Iceland, Reykjavik, Iceland

Olafur S. Indridason,

Background

Kidney function is known to decline with age, nevertheless, a uniform definition of glomerular filtration rate (GFR) has been applied to define chronic kidney disease irrespective of age. This has mostly been based on cross-sectional studies using single assessment of estimated glomerular filtration rate (eGFR), that have indicated worse outcome at eGFR <60 mL/min/1.73 m². The aim of this study was to examine the risk of all-cause mortality according to eGFR and proteinuria in persons aged >65 years in the general population.

Methods

We obtained all serum creatinine (SCr) and urine protein measurements from all clinical laboratories in Iceland in the years 2008-2016. Clinical data were obtained from nationwide electronic medical records. eGFR was calculated using the CKD-EPI equation and classified into categories; 0-29, 30-44, 45-59, 60-74, 75-89, 90-104 and >104 mL/min/1.73 m² eGFR category and proteinuria had to be persistent for >3 months. A multiple imputation method was used to account for missing urine protein measurement data. A joint model using repeated measurements was used to assess mortality and simultaneously account for decline in eGFR over time, adjusting for age as a continuous variable, sex and multiple comorbid conditions.

Results

We obtained 782,995 SCr values for 37,937 individuals aged over 65 years, of whom 23,344 (62%) had information on proteinuria. The median age was 75 (range, 66-106) years and 46% were men. Adjusted hazard ratios for all-cause mortality are demonstrated in the table.

Conclusion

Among elderly individuals, eGFR >104 mL/min/1.73 m² carries a high mortality risk, whereas eGFR of 45-74 without proteinuria is associated with the lowest mortality.

Adjusted hazard ratio (95% CI) for death according to eGFR and proteinuria

Funding

• Government Support – Non-U.S.