UAB Synopsis, Vol. 27, No. 18, May 12, 2008
Even small increases in serum creatinine levels during hospitalization raise the risk of end stage renal disease (ESRD) and mortality of elderly patients, according to a UAB-led study published in the March 24 issue of Archives of Internal Medicine.
Nephrologist Britt B. Newsome, MD, MPH, MSPH, lead author, says the 10-year retrospective study is the first systematic description of creatinine increase and longer-term ESRD and mortality risk. The results confirmed and extended the association between reductions in kidney function during hospitalization and risk of relatively short-term mortality.
“Previous studies had shown that a rise in serum creatinine level of 0.3 mg/dL or more during hospitalization was associated with higher in-hospital mortality, longer stay, and higher costs,” he says, “but little was known about the long-term risks of subsequent ESRD and mortality in this population.
“The long-term risks we observed suggest that even the least severe category of kidney injury may indicate a worse prognosis,” he says.
The study looked at a nationally representative sample of Medicare beneficiaries admitted with acute myocardial infarction to nonfederal US hospitals. Investigators analyzed changes in creatinine levels from 0.1 to 3.0 mg/dL.
The authors called for clinicians to target patients experiencing increases in creatinine levels for close monitoring and aggressive treatment. “In our sample, the prescriptions of â-blockers and aspirin, consistent with guidelines contemporaneous with the baseline cohort, exhibited a protective association with future mortality regardless of creatinine change during hospitalization, but patients with greater creatinine changes were undertreated,” study authors wrote.
“Incidences of ESRD and mortality were greatest among patients with larger changes in creatinine level, and all levels of serum creatinine increase were associated with greater independent risks of ESRD and mortality,” Dr. Newsome says.
The authors say the study also demonstrates the need for more sensitive markers of kidney function and biomarkers of acute kidney injury in clinical practice.
Other UAB authors are senior author Jeroan J. Allison, MD, MS; David G. Warnock, MD; and Catarina I. Kiefe, PhD, MD. Additional authors are William M. McClellan, MD, MPH, Emory University School of Medicine; Charles A. Herzog, MD, Cardiovascular Special Studies Center, US Renal Data System, Minneapolis, Minnesota; and Paul W. Eggers, PhD, the National Institute of Diabetes and Digestive and Kidney Diseases.