Hemoglobin Variability as Death Indicator for ESRD Patients

The American Society of Nephrology (ASN) released a new study concerning the determination of a death risk indicator for patients, who undergo dialysis for end-stage renal disease (ESRD). Scientists, among them Dr. Harold I. Feldman of University of Pennsylvania School of Medicine, Philadelphia, have found that hemoglobin variability over time can be a quite reliable predictor for an ESRD patient's death risk.

Hemoglobin is the part of the blood that carries the oxygen throughout the body. In healthy people, the hemoglobin variability remains within a narrow range. However, dialysis patients experience repeated drops in hemoglobin levels. If the hemoglobin level is low, a patient is diagnosed with anemia. When hemoglobin levels are low, adequate levels of oxygen are not supplied to the patient's organs and tissue. This can result in organ damage. This may particularly be true for the heart muscle and autonomic nervous system, which might explain the high rate of cardiovascular related diseases and deaths among ESRD patients.

Thus, low hemoglobin levels, anemia, can lead to complications from kidney failure and is a common cause of death in dialysis patients. While erythropoietin and intravenous iron are measures to treat kidney-failure related anemia, low blood counts and varying hemoglobin levels remain a problem among dialysis patients.

For the purpose of the study, the scientists utilized the data of almost 35,000 dialysis patients. The researchers specifically compiled data about the hemoglobin variability of these patients. The stability of hemoglobin levels among these chronic hemodialysis patients was measured to determine the effects of the hemoglobin variability on the risk of death in the patients.

The scientist's focus was on "Hb-Var." This is a new metric measure for the change in hemoglobin levels independent of their absolute values and trends over time. A high "Hb-Var" score indicates great hemoglobin variability, which, according to the results of the study, translates into a higher risk of death for an ESRD patient. This was still true after adjustments were made for absolute hemoglobin levels and trends in hemoglobin levels over time.

As a result of the study, the scientists think that "Hb-Var" scores may be a very useful tool in determining the effects of low hemoglobin in ESRD patients. Furthermore, it may explain, how anemia affects dialysis results in patients. Ultimately, based on a patient's "Hb-Var" score, physicians may be able to adjust a patient's treatment regimen to more effectively treat anemia to prevent or delay severe complications and the patient's death.

The study will appear in the December issue of the 'Journal of the American Society of Nephrology' under the title 'Hemoglobin Variability and Mortality in ESRD.'