Thomas J Weber1, James Koh2, Samantha M Thomas3, Joyce A Hogue4, Randall P Scheri4, Sanziana A Roman4, Julie A Sosa5. 1. Dept. of Medicine, Duke University Medical Center, Durham, NC, United States. Electronic address: thomas.weber2@dm.duke.edu. 2. Dept. of Surgery, Duke University Medical Center, Durham, NC, United States; Duke Cancer Institute, Duke University Medical Center, United States. 3. Dept. of Biostatistics and Bioinformatics, Duke University, United States; Duke Cancer Institute, Duke University Medical Center, United States. 4. Dept. of Surgery, Duke University Medical Center, Durham, NC, United States. 5. Dept. of Medicine, Duke University Medical Center, Durham, NC, United States; Dept. of Surgery, Duke University Medical Center, Durham, NC, United States; Duke Cancer Institute, Duke University Medical Center, United States; Duke Clinical Research Institute, Duke University Medical Center, United States.
Abstract
CONTEXT: A subset of PHPT patients exhibit a more severe disease phenotype characterized by bone loss, fractures, recurrent nephrolithiasis, and other dysfunctions, but the underlying reasons for this disparity in clinical presentation remain unknown. OBJECTIVE: We sought to identify new mechanistic indices that could inform more personalized management of PHPT. DESIGN: Pre-, peri-, and postoperative data and demographic, clinical, and pathological information from patients undergoing parathyroidectomy for PHPT were collected. Univariate and partial Spearman correlation was used to estimate the association of parathyroid tumor calcium sensing capacity with select variables. PATIENTS OR OTHER PARTICIPANTS: An unselected series of 237 patients aged >18years and undergoing parathyroidectomy for PHPT were enrolled. MAIN OUTCOME MEASURES: Calcium sensing capacity, expressed as the concentration required for half-maximal biochemical response (EC50), was evaluated in parathyroid tumors from an unselected series of 74 patients and assessed for association with clinical parameters. The hypothesis was that greater disease severity would be associated with attenuated calcium sensitivity and biochemically autonomous parathyroid tumor behavior. RESULTS: Parathyroid tumors segregated into two distinct groups of calcium responsiveness (EC50<3.0 and ≥3.0mM). The low EC50 group (n=27) demonstrated a mean calcium EC50 value of 2.49mM [95% confidence interval (CI): 2.43-2.54mM], consistent with reference normal activity. In contrast, the high EC50 group (n=47) displayed attenuated calcium sensitivity with a mean EC50 value of 3.48mM [95% CI: 3.41-3.55mM]. Retrospective analysis of the clinical registry data suggested that high calcium EC50 patients presented with a more significant preoperative bone mineral density (BMD) deficit with a t-score of -2.7, (95% CI: -3.4 to -1.9) versus 0.9, (95% CI: -2.1 to -0.4) in low EC50 patients (p<0.001). After adjusting for gender, age, BMI, 25 OH vitamin D level and preoperative iPTH, lowest t-score and calcium EC50 were inversely correlated, with a partial Spearman correlation coefficient of -0.35 (p=0.02). CONCLUSIONS: Impaired calcium sensing in parathyroid tumors is selectively observed in a subset of patients with more severe bone mineral density deficit. Assessment of parathyroid tumor biochemical behavior may be a useful predictor of disease severity as measured by bone mineral density in patients with PHPT.
CONTEXT: A subset of PHPT patients exhibit a more severe disease phenotype characterized by bone loss, fractures, recurrent nephrolithiasis, and other dysfunctions, but the underlying reasons for this disparity in clinical presentation remain unknown. OBJECTIVE: We sought to identify new mechanistic indices that could inform more personalized management of PHPT. DESIGN: Pre-, peri-, and postoperative data and demographic, clinical, and pathological information from patients undergoing parathyroidectomy for PHPT were collected. Univariate and partial Spearman correlation was used to estimate the association of parathyroid tumorcalcium sensing capacity with select variables. PATIENTS OR OTHER PARTICIPANTS: An unselected series of 237 patients aged >18years and undergoing parathyroidectomy for PHPT were enrolled. MAIN OUTCOME MEASURES: Calcium sensing capacity, expressed as the concentration required for half-maximal biochemical response (EC50), was evaluated in parathyroid tumors from an unselected series of 74 patients and assessed for association with clinical parameters. The hypothesis was that greater disease severity would be associated with attenuated calcium sensitivity and biochemically autonomous parathyroid tumor behavior. RESULTS:Parathyroid tumors segregated into two distinct groups of calcium responsiveness (EC50<3.0 and ≥3.0mM). The low EC50 group (n=27) demonstrated a mean calcium EC50 value of 2.49mM [95% confidence interval (CI): 2.43-2.54mM], consistent with reference normal activity. In contrast, the high EC50 group (n=47) displayed attenuated calcium sensitivity with a mean EC50 value of 3.48mM [95% CI: 3.41-3.55mM]. Retrospective analysis of the clinical registry data suggested that high calcium EC50 patients presented with a more significant preoperative bone mineral density (BMD) deficit with a t-score of -2.7, (95% CI: -3.4 to -1.9) versus 0.9, (95% CI: -2.1 to -0.4) in low EC50 patients (p<0.001). After adjusting for gender, age, BMI, 25 OH vitamin D level and preoperative iPTH, lowest t-score and calcium EC50 were inversely correlated, with a partial Spearman correlation coefficient of -0.35 (p=0.02). CONCLUSIONS: Impaired calcium sensing in parathyroid tumors is selectively observed in a subset of patients with more severe bone mineral density deficit. Assessment of parathyroid tumor biochemical behavior may be a useful predictor of disease severity as measured by bone mineral density in patients with PHPT.
Authors: Martin Almquist; Anders Bergenfelz; Hans Mårtensson; Mark Thier; Erik Nordenström Journal: Langenbecks Arch Surg Date: 2010-07-10 Impact factor: 3.445
Authors: M Andrew Nesbit; Fadil M Hannan; Sarah A Howles; Valerie N Babinsky; Rosie A Head; Treena Cranston; Nigel Rust; Maurine R Hobbs; Hunter Heath; Rajesh V Thakker Journal: N Engl J Med Date: 2013-06-27 Impact factor: 91.245
Authors: James Koh; Joyce A Hogue; Sanziana A Roman; Randall P Scheri; Hèléne Fradin; David L Corcoran; Julie A Sosa Journal: Endocr Relat Cancer Date: 2018-04 Impact factor: 5.678