| A meta-analysis conducted by the Chronic Kidney Disease Prognosis Consortium published on May 18, 2010 in The Lancet concluded that elevations in urinary albumin and albumin to creatinine ratio, which indicate kidney damage, as well as a reduction in the estimated glomerular filtration rate (eGFR) of the kidneys predict an increased risk of death from all causes over 2.1 to 11.6 years of follow-up. The Consortium, which was established in 2009 by KDIGO (Kidney Disease: Improving Global Outcomes), selected 21 studies including a total of 1,234,182 participants from 14 countries for their analysis. Over the follow-up periods, 45,584 deaths occurred. When the rate at which the glomerulii of the kidneys filter the blood dropped below a specific level, a greater risk of dying over follow-up occurred, which increased with declining rates. Additionally, an increase in albumin, a protein that is elevated in the urine when the kidneys are damaged, and a greater ratio of urinary albumin to creatinine (a product of creatine breakdown) were associated with significantly increased all-cause mortality risk. A similar elevation in risk was observed for deaths from cardiovascular disease. "eGFR less than 60 mL/min/1.73 m2 and albumin to creatinine ratio 10 mg/g or more are independent predictors of mortality risk in the general population," the authors conclude. "This study provides quantitative data for use of both kidney measures for risk assessment and definition and staging of chronic kidney disease." "People with high levels of albumin in their urine were at markedly higher risk of mortality than people with low levels of albumin in the urine," noted lead author Kunihiro Matsushita, MD, PhD, who is a postdoctoral fellow with the Johns Hopkins Bloomberg School of Public Health's Department of Epidemiology. "The risk of mortality was elevated by nearly 50 percent at 30 mg/gram albumin to creatinine ratio, which is the threshold for defining chronic kidney disease. In addition, mortality risk increased more than four-fold at high levels of albuminuria compared to an optimal level of 5 mg/gram. The data presented in this analysis confirm that the current thresholds are indicative of increased all-cause and cardiovascular mortality risk with both kidney filtration function and urine protein contributing to risk." |
