Reaching the hemoglobin (Hb) target range may be harder for female than male peritoneal dialysis (PD) patients receiving anemia treatment.
In a study of 2180 PD patients from the Polish PD Registry treated with erythropoiesis-stimulating agents (ESAs), women attained lower Hb concentrations than men (11.2 vs 11.5 g/dL), Monika Lichodziejewska-Niemierko, MD, PhD, of Medical University of Gdan´sk in Gdan´sk, Poland, and colleagues reported online in International Urology and Nephrology.
Women typically are diagnosed with anemia when their Hb level falls below 12.0 g/dL vs 13.0 g/dL in men. ESA therapy is initiated to avoid Hb falling below 9.0 g/dL. Yet the Hb target range with ESA treatment is the same for both genders. According to 2007 KDIGO (Kidney Disease: Improving Global Outcomes) guidelines, the Hb target range is 11.0 to 12.0 g/dL and no greater than 13.0 g/dL. ESAs generally should not be used to maintain Hb concentration above 11.5 g/dL, although there are individual exceptions, according to KDIGO 2012 guidelines.
Inadequate dialysis dose would explain ESA resistance and lower Hb in women, according to the investigators. They confirmed that higher Hb accompanied dialysis adequacy in prevalent PD patients, as well as in an independent group of 88 incident PD patients. But female patients from both groups, who had significantly higher Kt/V than males, still experienced lower Hb levels.
Hb levels trended lower for women despite higher ESA doses (2691 vs 2344 U/week). Recently diagnosed female patients attained lower Hb concentrations during all 3 years of follow-up, even as their average ESA dose increased from year to year. Women likewise scored higher on the erythropoietin resistance index (ERI): 5.66 vs 3.06.
After multiple regression analysis, gender emerged as an independent determinant of ERI after accounting for other relevant factors, such as age, co-morbidities, C-reactive protein, albumin, iron use, and Kt/V.
“Despite higher dialysis adequacy, Hb concentration in women treated with PD is significantly lower, and the ability to correct it impaired, as compared to men,” Dr Lichodziejewska-Niemierko and colleagues concluded.
In the general population, Hb reference values differ for men and women. “It is not clear whether, indeed, women require less Hb or whether lower concentrations results from iron deficiency in view of menstrual blood losses and, perhaps, poorer dietary intake,” the investigators wrote.