Many patients treated with hemodialysis remain anemic despite exogenous erythropoietin therapy, suggesting the anemia experienced by these patients is multifactorial in etiology. Iron deficiency, infection, inflammation, and malnutrition have been implicated in this process. Additionally, secondary hyperparathyroidism has been associated with anemia in adults, but little data exists on this topic in children.
Setting & Participants
Children treated in hemodialysis centers (N=588) within the Center for Medicare & Medicaid Services’ (CMS) 2002 Clinical Performance Measures (CPM) Project.
Intact parathyroid hormone (iPTH) assessed in October, November, and December 2001 and categorized as quintiles.
Outcomes & Measurements
Achievement of a serum hemoglobin ≥11 g/dl was assessed by Poisson regression adjusting for sex, age, race, dialysis vintage, vascular access type, single-pool Kt/V, serum albumin, normalized protein catabolic rate (nPCR), calcium-phosphorus product, and erythropoietin alpha dose.
Using the second quintile (iPTH 103–224 pg/ml) as the reference quintile, there was no association between quintile of iPTH and achievement of the hemoglobin goal: 1st quintile prevalence ratio (95% confidence interval) 1.0 (0.9, 1.2); 3rd quintile 0.95 (0.8, 1.1); 4th quintile 0.99 (0.8, 1.2); 5th quintile 0.97 (0.8, 1.1). Only serum albumin ≥ 3.5 g/dl (Bromocresol Green assay method) or ≥ 3.2 g/dl (Bromocresol Purple assay method) was significantly associated with meeting the hemoglobin goal 1.4 (1.2, 1.6).
The simultaneous collection of iPTH and hemoglobin limits causal inference. Iron stores and iron therapy are potential confounders not accounted for in this study.
In the largest study on this topic in children, there was no association found between iPTH levels and achievement of a hemoglobin ≥ 11g/dl. Serum albumin was strongly associated with achievement of the hemoglobin goal.