P80
FACTORS ASSOCIATED WITH PROGRESSION TO RENAL REPLACEMENT
THERAPY IN ELDERLY VERSUS YOUNGER PATIENTS AND IN DIFFERENT
CAUSES OF CHRONIC KIDNEY DISEASE
Chiu D, Kalra PA, Green D.
Institute of Population Health, University of Manchester, UK
INTRODUCTION: Elderly patients are less likely than younger patients with the same
estimated glomerular filtration rate (eGFR) to progress to end stage kidney disease (ESKD).
Similarly, different primary renal diseases also progress at different rates. Knowing whether
different clinical factors are associated with progression may allow for more individualised
targeted therapy for patients.
METHODS: This was a prospective longitudinal cohort study of patients with
eGFR<60mL/min managed in a tertiary nephrology unit. Patients were categorised according to
age (<65 years versus ≥65 years) and aetiology of renal disease. The study end point was renal
replacement therapy (RRT). A Cox proportional hazard model was applied to the three most
frequent kidney disease conditions in young and older patients, with multivariable adjustment
including known potential predictors of ESKD (gender, age, systolic blood pressure [sBP],
diabetes mellitus, ischaemic heart disease, heart failure, urinary protein creatinine ratio [uPCR],
renin angiotensin system blocker use, and eGFR). Results of each model were compared to
determine if the factors associated with progression differed between groups.
RESULTS: 2130 patients were included in the study. Median follow up was 42 months
(interquartile range 19-68 months), with 346 patients progressing to RRT (123 in ≥65 years
[10.3%], 223 in <65 years [24.1%]). The most common renal diseases in <65 years and
≥65years were diabetic nephropathy (15% and 14% respectively), hypertensive renal disease
(10% and 33%) and chronic glomerular disease (15% and 8%) The final model for these
diseases is shown in table 1. Table 2 compares older and younger patients across all diagnoses.
Table 1. Factors that are independently associated with progression to RRT in the three
most commonest renal disease. (Key:CCF- history of heart failure, CI-confidence interval)
Renal Disease
N
RRT
Variable
Hazard
p
95% CI
N
%
Ratio
Diabetic
304
68
22
eGFR
0.82
<0.01
0.77-0.89
Nephropathy
uPCR
1.00
<0.01
1.00-1.01
Hypertensive
496
48
10
CCF
0.12
0.01
0.02-0.64
Renal Disease
sBP
1.06
<0.01
1.02-1.11
uPCR
1.01
<0.01
1.00-1.01
eGFR
0.81
<0.01
0.72-0.92
Glomerular
233
51
22
Age
0.95
0.02
0.90-0.99
Disease
eGFR
0.78
<0.01
0.69-0.87
Table 2. Significant predictors in older versus younger patients including all diagnoses.
< 65 year old CKD patients
Variable
Hazard Ratio
p
95% CI
Age
0.97
<0.01
0.94-0.99
eGFR
0.87
<0.01
0.84-0.89
uPCR
1.00
<0.01
1.00-1.01
≥ 65 year old CKD patients
Variable
Hazard Ratio
p
95% CI
Age
0.93
0.01
0.88-0.98
eGFR
0.80
<0.01
0.76-0.85
uPCR
1.00
<0.01
1.00-1.01
Gender
0.49
0.04
0.25-0.97
Conclusion: Predictors of progression to RRT differ between primary renal diseases but not
between age groups when broadly categorised into greater or less than 65 years old.