Clinical Characteristics, Treatment Patterns, and Complications in Permanent Hypoparathyroidism: A Large Retrospective Cross-Sectional Study.

We aimed to evaluate treatment patterns, complications, and associated risk factors in a large cohort of patients with permanent hypoparathyroidism (HypoPT). This retrospective cross-sectional study included 958 adults with permanent HypoPT. Clinical and laboratory features were compared by etiology: postsurgical (86.4%) and nonsurgical (13.6%). The surgical group was further stratified by benign versus malignant thyroid histopathology. Risk factors for HypoPT-related complications were assessed using regression analyses. Patients received calcium, calcitriol, thiazide diuretics, cholecalciferol, teriparatide, or palopegteriparatide. Nephrolithiasis/nephrocalcinosis, basal ganglia calcifications (BGC), cataract, and hypercalciuria were detected in 13.5, 15.2, 20.8, and 44.4%, respectively, intravenous (IV) calcium was required in 8.4% within two years. Compared with postsurgical group, nonsurgical patients had lower calcium and parathyroid hormone (PTH), higher phosphate levels, greater calcium and calcitriol requirements, higher rates of BGC and IV calcium requirement, and higher T-scores (p < 0.05); nephrolithiasis/nephrocalcinosis and cataract were also more frequent (p = 0.086 and 0.072). Compared with malignant histopathology, benign group was associated with a higher BGC prevalence and higher phosphate levels (p = 0.022 and < 0.001). Hypercalciuria was independently associated with nephrolithiasis/nephrocalcinosis; older age, nonsurgical etiology, longer disease duration, hyperphosphatemia, and undetectable PTH with BGC; nonsurgical etiology with cataract; younger age, treatment suboptimal-adherence, and absence of hypercalciuria with IV calcium requirement (p < 0.05). Additionally, in univariable analyses, high-dose calcitriol was associated with nephrolithiasis/nephrocalcinosis and high-dose calcium with BGC (p < 0.05). In conclusion, HypoPT-related complications were associated with hyperphosphatemia, hypercalciuria, undetectable PTH, and high-dose conventional treatment, underscoring the need for better treatments and future studies to determine whether PTH-replacement therapy reduces complication risks.