James A. Delmez, M.D.

DEPARTMENT OF Int Med - Renal
Keywords: bone disease, calcitriol, hemodialysis, parathyroid hormone, renal failure

Renal osteodystrophy is a universal complication of renal failure and is a major cause of morbidity in the 300,000 patients undergoing dialysis in the United States. High turnover bone disease (osteitis fibrosa) is the most common form of renal osteodystrophy and is due to excessive rates of parathyroid hormone (PTH) secretion. Complex abnormalities of calcium, phosphorus and calcitriol metabolism in renal failure stimulate PTH secretion. We are investigating the clinical utility of new compounds that bind phosphorus in the bowel to avoid hyperphosphatemia. Calcitriol suppresses parathyroid secretion indirectly by increasing levels of calcium and directly by decreasing gene transcription of pre-pro PTH mRNA. Little is known of the effect of calcitriol in preventing the development of parathyroid glandular hyperplasia. This is being studied in a randomized, controlled trial of early use of intravenous calcitriol in hemodialysis patients. The mortality rate of hemodialysis patients in the United States is substantially higher than that in Europe or Japan. We have shown that this is due, in part, to widespread under-dialysis of patients. We are evaluating factors that contribute to the impaired delivery of hemodialysis treatments in patients with acute and chronic renal failure.