Bone turnover in short-term and long-term home parenteral nutrition for benign disease

In patients on home parenteral nutrition (HPN), a previous longitudinal his tomorphometric study on bone turnover showed a hyperkinetic feature in the early months of treatment that evolved to osteomalacia with low formation r ate. Our purpose was to assess the variations of biochemical markers of bon e turnover during HPN. Eight patients who had been receiving HPN for <4 mo (short-HPN) and eight patients receiving HPN for >12 mo (long-HPN) were stu died by serum osteocalcin (OC), parathyroid hormone, 25-hydroxyvitamin D, 1 ,25-dihydroxivitamin D, and aluminium; urinary cross-links of collagen; ser um; and urinary minerals. Short-HPN was assessed at baseline and >6 mo afte rward. Long-HPN was assessed only at baseline. In short-HPN, there was a hy perkinetic turnover at baseline. At follow-up, OC was similar to baseline, whereas cross-links, urinary calcium and magnesium decreased (P < 0.03), an d parathyroid hormone increased (P < 0.001). The variation of urinary calci um correlated with that of cross-links (r = 0.73, P < 0.04). In long-HPN, O C was low or low-normal in almost all the patients, and cross-links were no rmal. Mean OC was lower than that of short-HPN both at baseline (P < 0.003) and at follow-up (P < 0.002). The results suggest that in the early period of HPN bone metabolism improved from a hyperkinetic turnover to a positive balance. A low bone-formation rate appeared to be a characteristic feature of long-term HPN. Nutrition 2000;16:272-277. (C)Elsevier Science Inc. 2000 .