Session: S25-Hypoparathyroidism: More than Just Hypocalcemia
Room 258 (BCEC)
Conventional treatment of hypoparathyroidism with vitamin D analogs and calcium does not restore normal physiologic regulation of calcium homeostasis in the bone and kidney and may lead to renal insufficiency due to progressive nephrocalcinosis. Over the past two decades, we have evaluated various PTH 1-34 regimens including once-daily and twice-daily PTH 1-34 injections without the use of calcitriol or Ca supplements in adults and children of all etiologies. For each regimen, the PTH dosage was individualized for optimal control of calcium homeostasis. With increased frequency of injections, the total daily dose of PTH was markedly reduced and serum and urine calcium levels were maintained in the normal range throughout the day with reduced fluctuation. To further refine replacement therapy, we studied PTH delivery by insulin pump which represents a significant therapeutic breakthrough in the study of hypoparathyroidism. Pump delivery produced normal, steady-state calcium levels and avoided the rise in serum and urine calcium levels typically seen just after a PTH injection. Pump delivery of PTH allowed for simultaneous normalization of bone markers, serum calcium, and urine calcium excretion levels.
The essential therapeutic principles that underlie successful treatment of this rare disorder are: (1) Individualized PTH requirements depend upon the disease etiology; (2) smaller, more frequent doses of PTH replacement by subcutaneous injection reduces stimulation to bone and kidney and results in lower calcium excretion and markers of bone turnover; (3) PTH delivered by pump produces the most physiologic biochemical profile.