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/1.73 m² 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 m² were associated with 16%, 37%, and 64% greater risk of all-cause infection-related hospitalization, respectively, compared with eGFR_SCysC ≥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 m².

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.

Index Words:  Renal disease , chronic kidney disease , infection , clinical epidemiology