Endocrinology and Pd: Optimal Treatment of Anemia in Peritoneal Dialysis Patients

The optimal treatment of anemia in peritoneal dialysis is given by subcutaneous administration of epoetin. The optimal dosing frequency is in most patients 2 -3 injections per week, but in responsive patients once a week may be enough during the maintenance phase. Both before starting and during epoetin treatment it is necessary to monitor for factors causing hyporesponsiveness. The epoetin dose is adjusted monthly aiming at an increase in Hb concentration of 10 g/L per month. Further studies are required to define the optimal target Hb concentration. Iron supplements should be administered routinely. Parenteral iron may be used liberally when oral supplements are ineffective or inconvenient.

In the initial three-month period of peritoneal dialysis a marked increase in Hb concentration is common, and if epoetin treatment is necessary low starting doses will be sufficient. In patients with moderate anemia, adequate iron stores and iron availability, and no significant comorbidity, low starting doses are recommended (50 75 U kg-1 week-1). Patients with severe anemia or with comorbidity usually require higher doses and may be started with 75 150 kg-1 week-1. Hypertension is the principal adverse effect of epoetin treatment in patients with chronic renal failure, but it is usually easily controlled by fluid control and/or increased antihypertensive medication.

Hyperhomocysteinemia confers an independent increased risk of atherosclerosis in end-stage renal disease and is closely linked to plasma folate and pyridoxine concentrations

BACKGROUND

A high level of total plasma homocysteine is a risk factor for atherosclerosis, which is an important cause of death in renal failure. We evaluated the role of this as a risk factor for vascular complications of end-stage renal disease.

METHODS AND RESULTS

Total fasting plasma homocysteine and other risk factors were documented in 176 dialysis patients (97 men, 79 women; mean age, 56.3 +/- 14.8 years). Folate, vitamin B12, and pyridoxal phosphate concentrations were also determined. The prevalence of high total homocysteine values was determined by comparison with a normal reference population, and the risk of associated vascular complications was estimated by multiple logistic regression. Total homocysteine concentration was higher in patients than in the normal population (26.6 +/- 1.5 versus 10.1 +/- 1.7 mumol/L; P < .01). Abnormally high concentrations (> 95th percentile for control subjects, 16.3 mumol/L) were seen in 149 patients (85%) with end-stage renal disease (P < .001). Patients with a homocysteine concentration in the upper two quintiles (> 27.8 mumol/L) had an independent odds ratio of 2.9 (CI, 1.4 to 5.8; P = .007) of vascular complications. B vitamin levels were lower in patients with vascular complications than in those without. Vitamin B6 deficiency was more frequent in patients than in the normal reference population (18% versus 2%; P < .01).

CONCLUSIONS

A high total plasma homocysteine concentration is an independent risk factor for atherosclerotic complications of end-stage renal disease. Such patients may benefit from higher doses of B vitamins than those currently recommended.