Patterns and Predictors of Kidney Function Decline - Last Year prior to Dialysis

[okarol]

Vol. 111, No. 2, 2009   
Free Abstract     Article (Fulltext)     Article (PDF 217 KB)     

Original Paper

Patterns and Predictors of Kidney Function Decline in the Last Year prior to Dialysis
Vanina Ambrogia, Nathalie Thillya, Stéphanie Boinia, Jean-Marc Viriona, Michèle Kesslerb, Serge Briançona, Luc Frimatb

aDepartment of Clinical Epidemiology and Evaluation, CEC-CIE6 Inserm, University Hospital of Nancy, EA 4003, Nancy University, Nancy, and
bDepartment of Nephrology, Brabois Hospital, University Hospital of Nancy, Vandoeuvre-lès-Nancy, France

Address of Corresponding Author

Nephron Clin Pract 2009;111:c95-c101 (DOI: 10.1159/000191199)

 goto top of page Key Words

    * Pre-end-stage renal disease
    * Glomerular filtration rate decline
    * Associated factors
    * Dialysis planning

 goto top of page Abstract

Background: Establishing a comprehensive characterization of kidney function decline before dialysis is necessary to predict dialysis onset and prepare patients for replacement therapy. Aims: To investigate kidney function as measured by pattern and rate of decline in glomerular filtration rate (GFR) over the year preceding dialysis and to identify factors associated with a nonlinear GFR decline. Methods: We enrolled patients beginning dialysis in Lorraine (France) in 2005 and 2006, who were referred to a nephrologist more than 4 months before dialysis and had received more than 3 predialysis serum creatinine tests. From medical records, we retrospectively collected demographic and clinical data, as well as biological data during nephrologist follow-up, limited to 1 year before dialysis. A curve of GFR evolution by time was drawn for each patient and his linearity was evaluated graphically and confirmed by R2 > 0.7. Factors associated with a nonlinear decline in GFR were identified by logistic regression. Results: A total of 342 patients were included; the mean length of predialysis nephrologist care was 10.0 ± 9.7 months and the median number of serum creatinine tests per patient was 9 . Among these patients, 185 (54.1%) showed a linear decline in GFR and 157 (45.9%) a nonlinear decline. Patients with cardiovascular disease were 2.6 times more likely to show a nonlinear than linear decline in GFR (p < 0.0001). Conclusion: For patients with a linear decline in GFR, but not those with a nonlinear decline, date of dialysis onset can be estimated.

Copyright © 2009 S. Karger AG, Basel

 goto top of page Author Contacts

Dr. Nathalie Thilly
Service d'Epidémiologie et Evaluation Cliniques
CHU Nancy, CO n°34
FR-54035 Nancy Cedex (France)
Tel. +33 3 8385 2163, Fax +33 3 8385 1205, E-Mail n.thilly@chu-nancy.fr

 goto top of page Article Information

Received: April 22, 2008
Accepted: July 31, 2008
Published online: January 13, 2009
Number of Print Pages : 7
Number of Figures : 3, Number of Tables : 3, Number of References : 22

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[pelagia]

Does anyone who is pre-dialysis graph their test results?  I had been graphing my husband's creatinine for years.  Back in 2002, a neph told me that I should plot 1/creatinine versus date of the test to get a good approximation of how much kidney function he had left.  So 1/2 = 50% function, 1/5 = 20% function and 1/10 = 10%.  About 5 years ago I was able to predict that he would probably have to be on dialysis by late in 2008 or early in 2009, assuming the decline stayed linear.  I was never sure about that part and the nephs wouldn't give us any assurance about the likelihood of staying on that trend.  As this research points out, some folks show linear decline and others don't.  His trend turned out to be perfectly linear (with a r-squared of over .95, if you are familiar with statistics) over a period of about 20 years.

[paddbear0000]

Yes, I keep a chart of mine. My chart lists all of my kidney related results from the metabolic panel, plus anemia, cholesterol and urine related results. My function declined on a linear path for about 2 years, then leveled off for 3, and is now fluctuating between my leveled off function and reduced function. My heart is in perfect condition, so I guess I don't fit into their pattern.   

[openboat]

I've been charting 1/creatinine as well and it looks like a linear relationship to me, but I'm just a computational mathematics guy and not a statistics guy.  The latest labs declined more than would have been expected, I'm hopeful that I was just a bit dehydrated when they took the blood.

[paddbear0000]

I amend what I said before. After my function went back up to 17%, within a month, it plummeted down to 8%! Definitely not what their study said!

[pelagia]

Actually, they said that almost half of those studied had a non-linear decline.  That sounds like what you had PB.  But, they are also modeling a statistical relationship and even with some variation from creatinine from one time to another the trend could still be linear in a statistical sense.