[Consequences of the correction of post-transplantation hypophosphatemia on mineral metabolism].

AIM

To study the effect of the correction of post-transplantation Hypophosphatemia on mineral metabolism.

PATIENTS

15 patients with renal transplants for 3 to 12 months, Serum Creatinine "177 micmol/1, were treated with oral phosphorus (P) for persistent hypophosphatemia.

METHODS

3 periods of blood and urine collection at intervals of 3 weeks. T1 under basal treatment with oral P, T2 after 3 weeks off medication with P, Ca, or P binders. T3 3 weeks after going back on oral P supplements.

RESULTS

Serum P dropped from T1 to T2 (1.03 +/- 0.03 mmol/L to 0.83 +/- 0.03 mmol/L, p "0.0001), rising again in T3 to 1.06 +/- 0.03 mmol/L. From T1 to T2, PTHi decreased from 95.4 +/- 8.7 to 66.8 8.9pg/ml), osteocalcin rose from 3.8 +/- 1.2 to 16.6 +/- 2.3ng/ml (p<0.001) and 25-Vit D rose from 16.7 +/- 1.9 to 21.4 +/- 2.1 ng/l (p<0.001), with the reversal of these changes from T2 to T3 when serum P increased once again. There was a significant correlation between serum P and PTHi and serum P and 25-Vit D. There were no significant variations of the serum Ca, Alk. Phosph., ICTP and CaFE values in the three periods.

CONCLUSIONS

1-Serum P never dropped below 0.55 mmol/L, which had no clinical consequences, 2- When the P dropped, PTHi also dropped and osteocalcin and 25-Vit D rose, without any major variation in bone catabolism, 3- Correction of hypophosphatemia may delay recovery from secondary hyperparathyroidism.