Photo: A red blood cell amongst others 
A better life prognosis by
looking closer at haemoglobin

"Haemoglobin variability - a measure of the stability of levels of haemoglobin among chronic haemodialysis patients - provides a novel way of thinking about and understanding the relationship between anaemia and outcomes in ESRD," says Dr. Harold I. Feldman of University of Pennsylvania School of Medicine, Philadelphia, one of the study authors. The researchers used data on nearly 35,000 dialysis patients to analyse the effects of haemoglobin variability on the risk of death. They focused on a newly developed metric, termed “Hb-Var,” that measures variability in haemoglobin levels independent of their absolute values and trends over time.

The new study found that high Hb-Var scores - indicating greater haemoglobin variability - predicted a higher risk of death in dialysis patients. For each 1 g/dL (gram per decilitre) increase in Hb-Var, the risk of death increased by 33 percent, after adjustment for other factors.

The relationship between Hb-Var and mortality remained significant even after adjustment for absolute haemoglobin levels and trends in haemoglobin levels over time. Higher Hb-Var scores predicted an increased risk of death in nearly all subgroups of dialysis patients. "As postulated, higher levels of haemoglobin variability were associated with higher rates of death," says Feldman. The study identifies Hb-Var as a potentially valuable measure of the effects of low haemoglobin in ESRD, and lends new insights into how anaemia affects outcomes in dialysis patients.

Feldman concludes, "These findings may ultimately lead to health care practice changes regarding the management of anaemia - for example, the type, dose, and timing of treatment with erythropoietin and iron - that might improve outcomes among haemodialysis patients."; Source: American Society of Nephrology (ASN)