ADVANTAGE OF MEASUREMENT OF INTACT PTH IN THE PREDICTION OF CLINICAL RESPONSE AND CALCIUM METABOLISM AFTER SUBTOTAL PARATHYROIDECTOMY FOR RENAL OSTEODYSTROPHY.
As previously reported, the circulating half-life of carboxyterminal PTH is greatly prolonged in renal failure (mean t1/2 33.20 +/- 10.18 hrs), while intact PTH is much less affected (t1/2 less than one hour). Preoperative intact PTH levels were strongly predictive of clinical response to subtotal parathyroidectomy, and may help to differentiate the nature of metabolic bone disease in symptomatic dialysis patients. Intact PTH levels showed strong correlation with postoperative calcium metabolism, allowing prediction of extent of postoperative hypocalcemia. Carboxyterminal PTH levels, influenced by renal function as well as by functional parathyroid state, were poorly predictive of response to parathyroidectomy and not correlated with postoperative calcium metabolism.