Albuminuria, estimated GFR, traditional risk factors, and incident cardiovascular disease: the PREVEND (Prevention of Renal and Vascular Endstage Disease) study

Abstract

Background: Abnormal levels of both albuminuria and estimated glomerular filtration rate (eGFR) have been reported separately to be associated with cardiovascular risk. This study assessed the contribution of each separately in correctly identifying individuals at cardiovascular risk in the general population beyond traditional risk markers.

Study design: Prospective community-based cohort study.

Setting & participants: 8,507 individuals from the city of Groningen in the Netherlands followed up for 10.5 years for cardiovascular morbidity and mortality.

Predictor or factor: The contribution of albuminuria and eGFR separately on top of the traditional Framingham risk factors was assessed.

Outcomes: The composite of first occurrence of myocardial infarction, stroke, ischemic heart disease, revascularization procedure, and all-cause mortality.

Measurements: At the baseline visit, albuminuria was measured in 2 consecutive 24-hour urine samples. eGFR was calculated using the serum creatinine-based CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation.

Results: In multivariable Cox regression models, albuminuria, but not eGFR, was associated independently with the primary study outcome (HR, 1.08 [95% CI, 1.04-1.12] per doubling of albuminuria). When added to the risk model consisting of Framingham risk factors, albuminuria significantly contributed to better risk stratification, shown by an increase in net reclassification index of 7.2% (95% CI, 3.3%-11.0%; P<0.001) and increase in relative incremental discrimination improvement of 3.0% (95% CI, 0.9%-5.1%; P=0.006).

Limitations: The cohort includes mainly individuals of European ancestry. Therefore, results should not be extrapolated to other ethnicities.

Conclusion: In a general population cohort, albuminuria, but not eGFR, significantly adds to traditional cardiovascular risk factors in identifying individuals at risk of cardiovascular morbidity and all-cause mortality.