The Risk of Infection-Related Hospitalization With Decreased Kidney Function

Background: Moderate kidney disease may predispose to infection. We sought to determine whether decreased kidney function, estimated by serum cystatin C level, was associated with the risk of infection-related hospitalization in older individuals. Study Design: Cohort study. Setting & Participants: 5,142 Cardiovascular Health Study (CHS) participants with measured serum creatinine and cystatin C and without estimated glomerular filtration rate (eGFR) <15 mL/min/1.73m(2) at enrollment. Predictor: The primary exposure of interest was eGFR using serum cystatin C level (eGFR(SCysC)). Outcome: Infection-related hospitalizations during a median follow-up of 11.5 years. Results: In adjusted analyses, eGFR(SCysC) categories of 60-89, 45-59, and 15-44 mL/min/1.73 m(2) were associated with 16%, 37%, and 64% greater risk of all-cause infection-related hospitalization, respectively, compared with eGFRSCysC >= 90 mL/min/1.73 m2. When cause-specific infection was examined, eGFR(SCysC) of 15-44 mL/min/1.73 m2 was associated with an 80% greater risk of pulmonary and 160% greater risk of genitourinary infection compared with eGFR(SCysC) >= 90 mL/min/1.73 m(2). Limitations: No measures of urinary protein, study limited to principal discharge diagnosis. Conclusions: Lower kidney function, estimated using cystatin C level, was associated with a linear and graded risk of infection-related hospitalization. These findings highlight that even moderate degrees of decreased kidney function are associated with clinically significant higher risks of serious infection in older individuals. Am J Kidney Dis. 59(3): 356-363. (C) 2012 by the National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.