Preoperative imaging predicts change in bone mineral density after parathyroidectomy for primary hyperparathyroidism

Parathyroidectomy Improves Bone Density in Women With Primary Hyperparathyroidism and Preoperative Osteopenia

CONTEXT

Osteoporosis and/or bone fractures are indications of parathyroidectomy in primary hyperparathyroidism (PHPT), especially in women. However, the benefit of surgery in patients with osteopenia remains unclear.

OBJECTIVE

To evaluate bone mineral density (BMD) and bone remodeling biomarkers changes 1 year after parathyroidectomy in women with PHPT.

DESIGN

In the prospective, monocentric, observational prospective cohort with primary hyperparathyroidism patients (CoHPT) cohort, women operated for sporadic PHPT since 2016 with ≥1 year follow-up were included. BMD (dual-X ray absorptiometry) and bone remodeling biomarkers [cross-linked C-telopeptide (CTX), procollagen type 1 N-terminal propeptide (P1NP), and bone-specific alkaline phosphatases] were assessed before and 1 year after parathyroidectomy.

SETTING

Referral center.

PATIENTS

A total of 177 women with PHPT (62.5 ± 13.3 years, 83.1% menopausal, 43.9% osteopenic, and 45.1% osteoporotic) were included.

INTERVENTION

Parathyroidectomy.

MAIN OUTCOME MEASURE

BMD change between before and 1 year after parathyroidectomy.

RESULTS

Parathyroidectomy resulted in significant increase in BMD and decrease in serum bone remodeling biomarker concentrations. In the 72 patients with baseline osteopenia, mean BMD significantly increased at the lumbar spine [+0.05 g/cm2 (95% confidence interval [CI], 0.03-0.07)], the femoral neck [+0.02 g/cm2 (95% CI 0.00-0.04)], the total hip [+0.02 g/cm2 (95% CI 0.01-0.02)], and the forearm [+0.01 (95% CI 0.00-0.02)], comparable to osteoporotic patients. Among osteopenic patients, those with individual BMD gain (>0.03 g/cm2) at ≥1 site had higher preoperative serum CTX, P1NP, and urine calcium concentrations than those without improvement.

CONCLUSION

Parathyroidectomy significantly improved BMD and remodeling biomarkers in women with osteopenia, thereby supporting the benefit of parathyroidectomy in these patients. Preoperative serum CTX and P1NP concentrations could be useful to predict expected BMD gain.

A Significant Association between Parathyroid Adenoma Volume and Bone Mineral Loss at Distal Forearm

INTRODUCTION

The cortical bone is the most severely affected site in patients with primary hyperparathyroidism (PHPT) and thus, a low bone mineral density (BMD) is predominantly observed in distal forearm. Several studies have investigated potential associations between the weight of the gland and bone mineral loss. In this study, we wanted to investigate the relationship between parathyroid adenoma (PTA) volume and bone mineral loss.

METHODS

All patients with a diagnosis of PHPT who were operated at our hospital, and with a histologically proven single PTA were retrospectively analyzed. Z-scores were used as the main variable in our analysis to eliminate the effects of age, sex and gonadal status on BMD.

RESULTS

Total of 153 patients who met the inclusion criteria were eligible for the study. A significant negative correlation between the PTA volume and z-score for distal third of the radius (DR) (p = 0.006, r = -0.297) was shown. The cut-off value of gland volume for predicting cortical bone mineral loss was 9043.2 mm3. There was also a significant negative correlation between the 24-hour urine calcium and z-scores for lumbar vertebrae and total hip. A significant negative correlation was found between preoperative 25-hydroxy vitamin D levels and the PTA weight.

CONCLUSIONS

As the first study that evaluated any possible association between the volume of a parathyroid adenoma and bone mineral loss in patients with PHPT, we found a significant negative correlation between DR z-scores and resected gland volume. Since the volume of a PTA can also be determined by a preoperative US, our findings may be helpful during the preoperative evaluation of a patient with a preliminary diagnosis of PHPT.

Circulating miR-122-5p and miR-375 as Potential Biomarkers for Bone Mass Recovery after Parathyroidectomy in Patients with Primary Hyperparathyroidism: A Proof-of-Concept Study

Primary hyperparathyroidism (PHPT) is the leading cause of secondary osteoporosis. Although bone mineral density (BMD) tends to recover after parathyroidectomy in PHPT patients, the degree of recovery varies. Circulating microRNAs (miRNAs) profiles are known to be correlated with osteoporosis and fracture. We aimed to investigate whether osteoporotic fracture-related miRNAs are associated with postoperative BMD recovery in PHPT. Here, 16 previously identified osteoporotic fracture-related miRNAs were selected. We analyzed the association between the preoperative level of each miRNA and total hip (TH) BMD change. All 12 patients (among the 18 patients enrolled) were cured of PHPT after parathyroidectomy as parathyroid hormone (PTH) and calcium levels were restored to the normal range. Preoperative miR-19b-3p, miR-122-5p, and miR-375 showed a negative association with the percent changes in TH BMD from baseline. The association remained robust for miR-122-5p and miR-375 even after adjusting for sex, age, PTH, and procollagen type 1 N-terminal propeptide levels in a multivariable model. In conclusion, preoperative circulating miR-122-5p and miR-375 levels were negatively associated with TH BMD changes after parathyroidectomy in PHPT patients. miRNAs have the potential to serve as predictive biomarkers of treatment response in PHPT patients, which merits further investigation.