Correction of 25-OH-vitamin D deficiency improves control of secondary hyperparathyroidism and reduces the inflammation in stable haemodialysis patients. / La corrección del déficit de 25-OH-vitamina D mejora el control del hiperparatiroidismo secundario y el estado inflamatorio de pacientes estables en hemodiálisis.

INTRODUCTION: Patients on haemodialysis (HD) have a high prevalence of 25-OH-vitamin D (25-OH-D)deficiency. Secondary hyperparathyroidismis a common condition in these patients, which is very important to control. 25-OH-D is involved in regulating calcium homeostasis. As such, appropriate levels of this vitamin could help to control bone mineral metabolism. OBJECTIVE: To evaluate the effect 25-OH-D repletion in HD patients with 25-OH-D deficiency (<20ng/ml) on the control of secondary hyperparathyroidism and microinflammation status. PATIENTS AND METHODS: Prospective observational study in which stable patients on HD with 25-OH-D deficiency (<20ng/ml) were treated with oral calcifediol 0.266mcg/every 2 weeks for three months. Dialysis characteristics, biochemical parameters and drug doses administered were analysed before and after the correction of the deficiency. RESULTS: Forty-five stable HD patients with a mean age of 74.08±12.49 years completed treatment. Twenty-seven patients (60%) achieved 25-OH-D levels above 20ng/ml (23 with levels>30ng/ml and 4 between 20-30ng/ml). Parathyroid hormone levels decreased in 32 of the 45 patients, 23 of which (51%) achieved a>30% decrease from baseline. In terms of concomitant treatment, we observed a significant reduction in the selective vitamin D receptor activator dose, but no changes in calcimimetic or phosphate binders administration. In terms of malnutrition-inflammation status, a decrease in C-reactive protein was noted, although other microinflammation parameters, such as activated monocytes (CD14+/CD16+ and CD 14++/CD16+) were unchanged. No changes were observed in the levels of FGF-23. CONCLUSIONS: Correcting 25-OH-D deficiency in HD patients is associated with better secondary hyperparathyroidism control with lower doses of vitamin D analogues, as well as an improvement in inflammatory status. Our results support the recommendation to determine 25-OH-D levels and correct its deficiency in these patients.