Objective: The goal of this study was to clarify the clinical manifestation of hypercalcemia due to hypoadrenalism in hemodialysis (HD) patients.
Methods: We retrospectively analyzed the clinical characteristics of five HD patients who had presented with hypercalcemia due to adrenal insufficiency (age: 69 ± 7 [58-75] years old, time on HD: 13 ± 11 [2-32] years). We conducted corticotropin-releasing hormone (CRH) and adrenocorticotropic hormone (ACTH) stimulation tests. We also examined serum bone turnover markers before and after glucocorticoid replacement.
Results: All patients had critical illnesses at the onset of hypercalcemia. They had at least one symptom, such as eosinophilia, hypoglycemia, or fever. The prevalence of hypercalcemia due to adrenal insufficiency was 1.3% in maintenance HD patients on admission. The causes of adrenal insufficiency were isolated ACTH deficiency, pituitary apoplexy, pituitary atrophy, glucocorticoid withdrawal syndrome, and unilateral adrenalectomy. Serum calcium (Ca) levels corrected by serum albumin were maximally increased to 12.9 to 14.3 mg/dL in four anuric HD patients and mildly elevated to 10.4 mg/dL in a patient with residual diuresis. Their basal serum cortisol levels ranged from <1.0 to 15.4 μg/dL. Single CRH injections failed to increase serum cortisol in any of the patients. Glucocorticoid replacement acutely normalized serum Ca and decreased levels of carboxy-terminal telopeptide of type I collagen, a marker of bone resorption.
Conclusion: Adrenal insufficiency could therefore be an occult cause of hypercalcemia in anuric HD patients who are critically ill.