Primary hyperparathyroidism, hypercalciuria, and bone recovery after parathyroidectomy

Area of Science:

• Endocrinology
• Nephrology
• Bone Metabolism

Background:

• Primary hyperparathyroidism (PHPT) often leads to bone loss and kidney issues.
• Parathyroidectomy is effective in improving bone mineral density (BMD) in most PHPT patients.
• The interplay between hypercalciuria, renal function, and bone recovery post-parathyroidectomy requires further elucidation.

Purpose of the Study:

• To investigate the relationship between 24-hour urinary calcium, kidney function, and bone recovery after parathyroidectomy in PHPT patients.
• To identify predictors of BMD improvement following parathyroidectomy.

Main Methods:

• A cohort of 150 PHPT patients underwent analysis of BMD, estimated glomerular filtration rate (eGFR), and 24-hour urinary calcium before and one year after parathyroidectomy.
• Patients were randomized to receive either cholecalciferol and calcium carbonate or calcium carbonate alone.
• Statistical analyses, including multivariable modeling, were used to assess associations.

Main Results:

• Baseline 24-hour urinary calcium correlated positively with serum calcium, parathyroid hormone, 25-OH-D, bone turnover markers, and eGFR, and inversely with age.
• BMD at the lumbar spine and hip increased significantly post-parathyroidectomy in both treatment groups.
• Elevated baseline 24-hour urinary calcium (>10 mmol/d) was independently associated with greater BMD increases at the total hip, alongside plasma parathyroid hormone levels.

Conclusions:

• Baseline 24-hour urinary calcium exceeding 10 mmol/d is a significant independent predictor of BMD improvement after parathyroidectomy in PHPT.
• These findings underscore the importance of assessing urinary calcium levels when considering parathyroidectomy for PHPT.
• Further research may explore targeted interventions for patients with high urinary calcium to optimize bone health outcomes.