EFFECTS OF TREATMENT OF SECONDARY HYPERPARATHYROIDISM ON THE LIPID PROFILE IN PATIENTS ON HEMODIALYSIS

Abnormalities in circulating lipoprotein concentrations are a characte ristic finding in patients undergoing dialytic therapy. A substantial number of these patients display type IV hyperlipoproteinemia. Certain data suggest that secondary hyperparathyroidism may induce disturbanc es in lipid metabolism. To evaluate the effects of pulse calcitriol th erapy on the lipid profile in these patients, we undertook a prospecti ve study in 12 patients on stable bicarbonate hemodialysis. Lipid para meters comprising cholesterol and the low-as well as the high-density lipoprotein subfractions, triglycerides, apolipoproteins A and B, seru m parathyroid hormones (iPTH), alkaline phosphatase, calcium, phosphor us, hematocrit, and blood urea were obtained prior to commencement of pulse calcitriol therapy and again 8-10 weeks later. Calcitriol therap y was associated with a decrease in serum iPTH levels (701 +/- 103.9 v s. 220.3 +/- 50.5 pmol/l; p < 0.001). Significant increases in high-de nsity lipoprotein cholesterol (32.8 +/- 2.7 vs. 38.8 +/- 2.3 mmol/l; p < 0.05) and apolipoprotein A-I (107.8 +/- 6.1 vs. 121.8 +/- 5.8 g/l; p < 0.05) were noted during the course of the study. Moreover, serum i PTH correlated inversely with high-density lipoprotein cholesterol and apolipoprotein A-I. There were no changes in other lipid parameters e xcept for low-density lipoprotein cholesterol which showed a tendency to increase, We conclude that in short-term study, pulse oral calcitri ol therapy is associated with an improvement in the lipid profile in p atients with secondary hyperparathyroidism. However, it remains to be established whether ameliorating the uremic dyslipidemia results in an y long-term clinical benefits.