Primary Hypoparathyroidism and Chronic Kidney Disease: Is It Always Related to Treatment?

Abstract

Abstract Background: Anterior neck surgery is the leading cause of acquired hypoparathyroidism. Renal failure is the most common complication of treatment for hypoparathyroidism with active vitamin D and calcium supplements. However, the contribution of hypoparathyroidism to development of CKD in the absence of treatment is not well studied. Clinical Case: A 70-year old woman was brought to ED after she was found on the floor at home. Medical history was significant only for a partial thyroidectomy over 20 years prior, without reported post-operative complications. She was not taking any medications. Pertinent physical findings included altered mental status, hand tremors, involuntary contractions of left arm, and ashen skin. Laboratory tests upon presentation were significant for profoundly low albumin-corrected calcium of 3.68 mg/dL (n 8.6–10.2 mg/dL); low PTH 9.9 pg/dL (n 15–65 pg/dL); elevated phosphorous 8.5 mg/dL (n 2.7–4.5 mg/dL), elevated BUN 36 mg/dL (n 8–22 mg/dL), creatinine 2.76 mg/dL (n 0.5–1.3 mg/dL) and elevated CK of 4787 U/L (n 10–225 U/L). EKG showed QT interval prolongation. Head CT revealed periventricular and basal ganglia calcifications. Renal US was normal. The patient was treated with IV and PO calcium acetate and active vitamin D with resolution of the symptoms while calcium level improved. Post hospital follow-ups were significant for persistent hyperphosphatemia, which gradually improved with calcium and non-calcium phosphate binders as well as active vitamin D. Although this patient presented with acute hypocalcemia, she had chronic hypoparathyroidism as evidenced by basal ganglia calcifications. In the absence of other medical conditions, including negative PTH antibodies, or treatment for chronic hypoparathyrodism, the most likely cause of the CKD was chronic hypoparathyroidism itself. Conclusion: Post-surgical hypoparathyroidism may develop many years after surgery and can be asymptomatic. It is essential to diagnose this condition early to avoid late complications of the disease. The kidneys are particularly affected. Conventional treatment with calcium and vitamin D analogues is associated with ectopic mineralization and can lead to CKD. Untreated hypoparathyroidism on the other hand, can also lead to CKD, posing therapeutic challenges on finding the most appropriate and balanced treatment regimen in order to prevent further renal complications. Close monitoring and optimizing therapy plays critical role in preserving renal function of patients with hypoparathyroidism.