CKD classification based on estimated GFR over three years and subsequent cardiac and mortality outcomes: a cohort study.
BACKGROUND
It is unknown whether defining chronic kidney disease (CKD) based on one versus two estimated glomerular filtration rate (eGFR) assessments changes the prognostic importance of reduced eGFR in a community-based population.


METHODS
Participants in the Atherosclerosis Risk in Communities Study and the Cardiovascular Health Study were classified into 4 groups based on two eGFR assessments separated by 35.3 +/- 2.5 months: sustained eGFR < 60 mL/min per 1.73 m(2) (1 mL/sec per 1.73 m(2)); eGFR increase (change from below to above 60); eGFR decline (change from above to below 60); and eGFR persistently >or=60. Outcomes assessed in stratified multivariable Cox models included cardiac events and a composite of cardiac events, stroke, and mortality.


RESULTS
There were 891 (4.9%) participants with sustained eGFR < 60, 278 (1.5%) with eGFR increase, 972 (5.4%) with eGFR decline, and 15,925 (88.2%) with sustained eGFR > 60. Participants with eGFR sustained < 60 were at highest risk of cardiac and composite events [HR = 1.38 (1.15, 1.65) and 1.58 (1.41, 1.77)], respectively, followed by eGFR decline [HR = 1.20 (1.00, 1.45) and 1.32 (1.17, 1.49)]. Individuals with eGFR increase trended toward increased cardiac risk [HR = 1.25 (0.88, 1.77)] and did not significantly differ from eGFR decline for any outcome. Results were similar when estimating GFR with the CKD-EPI equation.


CONCLUSIONS
Individuals with persistently reduced eGFR are at highest risk of cardiovascular outcomes and mortality, while individuals with an eGFR < 60 mL/min per 1.73 m(2) at any time are at intermediate risk. Use of even a single measurement of eGFR to classify CKD in a community population appears to have prognostic value.
Weiner
Daniel E
DE
Division of Nephrology, Tufts Medical Center, 800 Washington Street, Boston, MA 02111, USA. dweiner@tuftsmedicalcenter.org
Krassilnikova
Maria
M
Tighiouart
Hocine
H
Salem
Deeb N
DN
Levey
Andrew S
AS
Sarnak
Mark J
MJ
D000368:Aged; D000369:Aged, 80 and over; D050197:Atherosclerosis / Q000401:mortality*; D001900:Boston / Q000453:epidemiology; D015897:Comorbidity; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D015994:Incidence; D007676:Kidney Failure, Chronic / Q000175:diagnosis* / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D020521:Stroke / Q000401:mortality*; D016019:Survival Analysis; D015996:Survival Rate