Etiological Examination and Treatment Approaches of Patients withHypercalcemia

Hypercalcemia is one of the most significant electrolyte disorders and can be a clinical manifestation of a treatable disease if detected early.1 It is mainly caused by PHPT (Primary Hyperparathyroidism) and malignancy, which account for 90% of hypercalcemia cases.2 AKI (Acute Kidney Injury) is a common complication of severe hypercalcemia, and the use of RRT (Renal Replacement Therapy) is often necessary for rapid and effective correction.3 There is limited literature on the current etiological studies related to hypercalcemia. The purpose of this thesis is to evaluate patients diagnosed and treated for hypercalcemia, contribute to the literature, and serve as a reference for future studies. A total of 2217 patients who were followed between 2017 and 2021 at our hospital and had corrected calcium levels above 10.9 mg/dl in two measurements were included in the study. The demographic data of the patients, as well as serum calcium, albumin, phosphorus, PTH (Parathyroid Hormone), vitamin D, DEXA (bone densitometry) measurements, bone metastasis, and hemodialysis treatment data, were retrospectively reviewed through the internet data system. The distribution of variables was assessed using the Kolmogorov-Smirnov test. Independent quantitative data were analyzed using independent samples t-test, Kruskal-Wallis, and Mann-Whitney U test. Independent qualitative data were analyzed using chi- square test, and when the chi-square test conditions were not met, Fisher's test was used. SPSS 28.0 software was used for the analyses. In the studied patient group, 30% (n=705) had hypercalcemia associated with malignancy, and 7% (n=156) were related to hyperparathyroidism. There was no linear relationship between PTH and calcium elevation, and this is often attributed to mild to moderate hypercalcemia in PHPT cases. The need for urgent renal replacement therapy due to the cause of hypercalcemia was found to be 0.4% (n=9). The rate of osteoporosis in hypercalcemic PHPT was 56.2% (n=79), and more comprehensive studies are needed to obtain clearer data in normocalcemic PHPT. 12 The association between vitamin D and metastasis could not be accurately evaluated due to the low number of cases, and there is a need for detailed studies in this regard. Conclusion Hypercalcemia is frequently associated with malignancy and hyperparathyroidism. The relationship between PTH and calcium elevation is not linear, particularly in cases of PHPT with mild to moderate hypercalcemia. The need for urgent renal replacement therapy due to hypercalcemia is relatively low. Osteoporosis is prevalent in hypercalcemic PHPT, and further detailed studies are required for normocalcemic PHPT. Due to the scarcity of cases, the association between vitamin D and metastasis needs more investigation.