Sporadic Primary Hyperparathyroidism and Stone Disease: a Comprehensive Metabolic Evaluation Before and After Parathyroidectomy

Objectives to characterize the stone risk and the impact of parathyroidectomy on the metabolic profile of patients with primary hyperparathyroidism (PHPT) and urolithiasis. Subjects and Methods We analyzed the prospectively collected charts of patients treated at our stone clinic from Jan/2001-Jan/2016 searching for patients with PHPT and urolithiasis. Imaging evaluation of the kidneys, bones and parathyroid glands were assessed. We analyzed the demographic data, serum and urinary parameters before and after parathyroidectomy. Statistical analysis included paired T/Fisher/Spearman/ANOVA tests. Significance was set at p<0.05. Results 51 patients were included. Mean age was 57.1±12.1years and 82.4% were female. Before parathyroidectomy, mean calcium and PTH levels were 11.2±1.0mg/dL and 331±584pg/dL, respectively. Hypercalcemia was present in 84.3% of patients. All eight patients with normal calcium had elevated PTH. Only two subjects did not have PTH above normal range, though both had elevated calcium. The most common urinary disorders were low urinary volume (64.7%), hypercalciuria (60.8%), high urinary pH (41.2%) and hypocitraturia (31.4%). After parathyroidectomy, the number of patients with hypercalcemia (n=4;7.8%), elevated PTH (n=17;33.3%) and hypophosphatemia (n=3;5.9%) significantly decreased (p<0.001). The number of urinary abnormalities decreased and there was a reduction in urinary calcium levels (p<0.001), pH (p=0.001) and citrate (p=0.003). Conclusion Individuals with PHPT and nephrolithiasis frequently present elevated baseline PTH and calcium. Low volume, hypercalciuria, high urinary pH, and hypocitraturia are the most frequent urinary disorders. Parathyroidectomy is effective in normalizing serum calcium and PTH levels, though other urinary metabolic may persist. Patients should be monitored for the need for citrate supplementation. This article is protected by copyright. All rights reserved.