Effect of bicarbonate based dialysate versus acetate based dialysate on parathormone blood level in haemodialysis treated chronic renal failure patients

Abstract

Renal osteodystrophy may result from multiple factors. Hyperparathyroidism, hypocalcaemia, hyperphosphataemia, altered vitamin D metabolism and metabolic acidosis are the most common factors. The clinical impact of acidosis on intact parathyroid hormone (iPTH) level and calcium–phosphate metabolism is still a matter of debate. In the present study we compared the effect of bicarbonate haemodialysis versus acetate haemodialysis on iPTH blood level. Forty chronic renal failure (CRF) patients on acetate based regular haemodialysis treatment and 10 normal control subjects were studied. All patients and controls were subjected to laboratory investigations including predialysis blood urea, serum creatinine, calcium (Ca), phosphorus (PO4), alkaline phosphatase (ALP), bicarbonate and iPTH before the start of the study. Then patients were randomly assigned to one of two groups: group I continued haemodialysis with acetate based dialysate for 6 months, group II shifted to bicarbonate based haemodialysis. After 6 months, the previously done investigations were repeated. The results revealed that group II patients who shifted to bicarbonate haemodialysis had a significant increase in serum bicarbonate levels from 18.02 ± 0.37 mmol/L to 20.34 ± 0.71 mmol/L (P<0.05) and a decrease in their serum levels of iPTH from 393.6 ± 113 pg/ml to 307.6 ± 90.1 pg/ml (P<0.05) and serum level of PO4 from 1.48 ± 0.16 mmol/L to 1.44 ± 0.11 mmol/L (P<0.05). On the other hand, group I patients who continued on acetate haemodialysis had no changes as regard serum bicarbonate, iPTH or PO4 levels. We can conclude that bicarbonate haemodialysis is better than acetate haemodialysis due to better correction of uraemic acidosis and improvement of secondary hyperparathyroidism.