Abstract
Chronic kidney disease increases the risk of all-cause mortality, cardiovascular disease and kidney failure, even after accounting for traditional risk factors such as hypertension and diabetes mellitus. This meta-analysis assessed the independent and combined associations of estimated glomerular filtration rate (eGFR) and albuminuria with mortality. Kidney Disease: Improving Global Outcomes has taken the lead in establishing the Chronic Kidney Prognosis Consortium. This Consortium pooled standardized data for all-cause and cardiovascular mortality from studies containing at least 1000 participants and baseline information about eGFR and urine albumin concentrations.
The analysis included 105,872 participants from 14 studies with urine albumin-to-creatinine ratio (ACR) measurements and 1,128,310 participants from seven studies with urine protein dipstick measurements. The median age of the participants was 61 y in studies with ACR measurements and 62 y in studies with dipstick measurement. Median follow-up time was 7.9 y, during which 45,584 deaths occurred. Data for 9637 deaths due to cardiovascular disease were reported in 15 of the 21 studies.
This meta-analysis demonstrates an exponential increase in risk of mortality at low eGFR. The risk became significant around 60 mL/min/1.73 m2 and was two-fold greater at eGFR 30–45 mL/min/1.73 m2 compared with optimum eGFR (90–104 mL/min/1.73 m2). The relationship between eGFR and mortality was independent of albuminuria and potential confounders. Urine dipstick testing was found to be useful in risk stratification despite being a less precise measure of albuminuria.
The authors concluded that eGFR less than 60 mL/min/1.73 m2 and ACR greater than 1.1 mg/mmol (10 mg/g) are independent predictors of mortality risk in the general population, and that this study provides quantitative data for use of both renal measures for risk assessment and definition and staging of chronic kidney disease.