Correlation of Parathyroid Hormone and Hemoglobin Levels in Normal Renal Function

Abstract

Background. Primary hyperparathyroidism and vitamin D deficiency are both associated with increased prevalence of anemia. Relationship of hemoglobin and parathyroid hormone in normal ranges were not investigated appropriately. Methods. We analysed laboratory data of 476 patients without primary hyperparathyroidism. The patients had concurrent measurements of calcium, phosphorus, alkaline phosphatase, parathyroid hormone, 25-OH vitamin D and hemoglobin. Results. Parathyroid hormone was negatively correlated with hemoglobin (p=0.01), the correlation persisted after correction for vitamin D levels (p=0.045), and in sub-group of normal (>20 ng/mL) 25-OH vitamin D levels (p=0.005). Parathyroid hormone was also correlated negatively with ferritin (p=0.02), correlation persisted after being adjusted to vitamin D (p=0.021). In anemic patients, these with low ferritin (<12 ng/mL) had higher PTH levels than these with higher ferritin despite having similar calcium and vitamin D levels (p=0.014). Conclusion. Interaction of parathyroid hormone and erythropoiesis seems to be present in normal ranges where erythropoietin may mediate key roles regulating both.