Abstract
Using an electrode-type apparatus (Horiba Seisakusho), serum ionized calcium (Ca_??_) was measured in patients with various kinds of abnormal calcium metabolism. Patients with hypercalcemia included 8 patients with primary hyperarathyroidism, 6 patients with breast cancer with bone metastases and 18 patients with untreated Graves' disease. Those with hypocalcemia included 54 patients after total thyroidectomy for thyroid cancer, divided into 3 groups, a tetany group, vitamin-D-administration group and autograft group. In order to compare the Ca_??_, total calcium (CaT) and corrected Ca(CaC) with the corresponding values in the control group, Standard Deviation Index (SDI) was used. Ca_??_ was significantly higher than the control group in each disease with hypercalceia, whereas it was lower than the control group in the group with hypocalcemia. A significant correlation of r=0.910, P<0.01 was found between Ca_??_ and CaT. With SDI, however, Ca_??_ showed more a distinct variation than CaT or CaC. Ca_??_ thus appear to be more useful as an index of abnormal calcium metabolism than CaT or CaC.
