Dynamic follow-up of the intact parathormone levels in hemodialysis patients treated with Rocaltrol and calcium.

The object of the present study was to follow prospectively the serum levels of intact parathormone (PTH) of hemodialysis patients and the subsequent changes following the oral administration of 1.25(OH)D3 and calcium. METHODS: We studied 30 chronic renal failure hemodialysis patients--16 men and 14 women, aged 20-70 years. Twenty-one of them were on hemodialysis with duration of up to 5 years (Group 1) and nine--up to 10 years (Group 2). All patients received oral supplementation therapy with 1.0 elemental calcium and Rocaltrol (Roche) 0.25 microgram/day. We measured the serum calcium, ionized calcium, serum phosphorus, alkaline phosphatase and the intact serum PTH levels in intervals of 12 months. RESULTS: Patients with duration of dialysis of up to 5 years had a significantly lower baseline PTH level of 392.5 +/- 94.7 pg/ml versus 896.4 +/- 160.7 pg/ml for those from the second group (P < 0.01). The intact PTH levels showed a tendency towards decrease--at the end of the study they were as follows: 372.02 +/- 76.9 for group 1 versus a significant increase for those from group 2--serum PTH levels of 1793.65 +/- 290.3 (P < 0.02). The differences in alkaline phosphatase and serum phosphorus levels at the end of the study period failed to reach statistical significance. Serum calcium levels were increased in both groups following the initiation of treatment but the difference was statistically significant only for group 2. A significant positive correlation was observed between the duration of hemodialysis treatment and the intact serum PTH levels. CONCLUSIONS: 1. Long-term low-dose conventional calcitriol therapy in combination with calcium supplementation could slow the progression of secondary hyperparathyroidism in some hemodialysis patients. 2. Low-dose therapy with active vitamin D-metabolites is effective only in hemodialysis patients with baseline serum PTH levels below 500 pg/ml and without pronounced hyperphosphatemia.