Survival in primary hyperparathyroidism over five decades (1965-2010) a population-based retrospective study

Association between primary hyperparathyroidism and cardiovascular outcomes: A systematic review and meta-analysis

BACKGROUND

Excess parathyroid hormone (PTH) is associated with an increased risk of cardiovascular disease (CVD).

PURPOSE

We aimed to evaluate the correlation between primary hyperparathyroidism (PHPT) and CVD or cardiovascular (CV) death.

DATA SOURCES

Comprehensive searches of PubMed, Embase and ClinicalTrials.gov until May 20, 2023 with the following keywords: "primary hyperparathyroidism," "cardiovascular disease," and "mortality."

STUDY SELECTIONS

Cohort studies and randomized controlled trials comparing PHPT patients to the general population and those who had received parathyroidectomy (PTX) to those who did not.

DATA EXTRACTION

Three investigators independently extracted data and assessed study quality.

DATA SYNTHESIS

Eleven cohort studies and one randomized controlled trial were identified, including 264,227 PHPT patients with or without PTX, and the average age reported in the studies was 62 years. PHPT was associated with a higher risk of total death (RR 1.39 [95 % confidence interval (CI) 1.23-1.57) and CV death (RR 1.61 [95 % CI 1.47-1.78]) than the general population. However, there was no significant difference in CVD risk between patients with PHPT and the general population (RR 1.73 [95 % CI 0.87-3.47]). When compared to patients without PTX, PTX had a lower risk of CV death (RR 0.75 [95 % CI 0.71-0.80]), total death (RR 0.64 [95 % CI 0.60-0.70]) and CVD (RR 0.92 [95 % CI 0.90-0.94]).

LIMITATION

High heterogeneity among the included articles, and most of them were retrospective and older studies.

CONCLUSIONS

PHPT was associated with higher risk of total death and CV death while PTX was associated with lower risk of total death, CV death, and CVD.

Dicer-Mediated mTORC1 Signaling and Parathyroid Gland Integrity and Function

Key Points

Background

Secondary hyperparathyroidism of CKD contributes significantly to patient morbidity and mortality. The underlining mechanisms of CKD-induced secondary hyperparathyroidism remain elusive. We previously demonstrated that PT-Dicer −/− mice, with parathyroid-specific deletion of the microRNA (miRNA)-processing enzyme Dicer and consequently miRNA, maintain normal basal serum parathyroid hormone (PTH) levels but do not develop secondary hyperparathyroidism induced by CKD. In addition, we showed that the parathyroid mechanistic target of rapamycin complex 1 (mTORC1) pathway is activated in CKD. We now explored the roles of Dicer/miRNA and mTORC1 in parathyroid development and function.

Methods

We generated mice with parathyroid-specific Dicer (PT-Dicer −/− ), mechanistic target of rapamycin (PT-mTOR −/− ), or tuberous sclerosis complex 1 (PT-Tsc1 −/− ) deficiency combined with yellow fluorescent protein (YFP) or tdTomato expression to identify the parathyroids by fluorescence microscopy. CKD was induced by an adenine-rich high-phosphate diet.

Results

Despite normal basal serum PTH levels, PT-Dicer −/− mice displayed apoptotic loss of intact parathyroid glands postnatally and reduced mechanistic target of rapamycin activity. PT-mTOR −/− mice lacked intact parathyroid glands yet maintained normal serum PTH levels, mirroring the phenotype of PT-Dicer −/− mice. Conversely, PT-Tsc1 −/− mice with hyperactivated mTORC1 exhibited enlarged glands along with elevated basal serum PTH and calcium levels. Significantly, PT-Dicer −/− ;Tsc1 −/− double knockout mice preserved intact parathyroid glands and reinstated CKD-induced secondary hyperparathyroidism.

Conclusions

mTORC1 operates downstream of Dicer and miRNA in the parathyroid and is essential for maintaining postnatal parathyroid gland integrity throughout life and for the pathogenesis of CKD-induced secondary hyperparathyroidism.

Sex-Stratified Predictors of Prolonged Operative Time and Hospital Admission in Outpatient Parathyroidectomy

Our retrospective database study investigates sex-stratified predictors of prolonged operative time (POT) and hospital admission following parathyroidectomy for primary hyperparathyroidism (PHPT). The 2016 to 2018 American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) was queried for patients with PHPT undergoing parathyroidectomy. Cases analyzed were all outpatient status, arrived from home, coded as non-emergent, and elective. POT was defined by the 75th percentile. Hospital admission was defined as LOS ≥ 1 day. Univariate and multivariable binary logistic regressions were utilized. Of 7442 cases satisfying inclusion criteria, the majority were female (78.0%) and White (78.5%). Median OT (IQR) for females and males was 77 (58-108) and 81 (61-109) minutes, respectively (P = 0.003). 1965 (33.9%) females and 529 (32.3%) males required hospital admission. Independent predictors of POT included ASA class III/IV (aOR 1.342, 95% CI 1.007-1.788) and obesity (aOR 1.427, 95% CI 1.095-1.860) for males (P < 0.05). Independent predictors of hospital admission included age (aOR 1.008, 95% CI 1.002-1.014), ASA class III/IV (aOR 1.490, 95% CI 1.301-1.706), obesity (aOR 1.309, 95% CI 1.151-1.489), dyspnea (aOR 1.394, 95% CI 1.041-1.865), chronic steroid use (aOR 1.674, 95% CI 1.193-2.351), and COPD (aOR 1.534, 95% CI 1.048-2.245) for females (P < 0.05); and ASA class III/IV (aOR 1.931, 95% CI 1.483-2.516) and bleeding disorder (aOR 2.752, 95% CI 1.443-5.247) for males (P < 0.005). In conclusion, predictors of POT and hospital admission following parathyroidectomy for PHPT differed by patient sex. Identifying patients at risk for POT and hospital admission may optimize healthcare resource utilization. Level of Evidence: IV.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-04444-3.

Morbidity Associated With Primary Hyperparathyroidism-A Population-based Study With a Subanalysis on Vitamin D

CONTEXT

Primary hyperparathyroidism (PHPT) is associated with increased risk of morbidity and death, and vitamin D levels are a potentially confounding variable.

OBJECTIVE

The aim of this study was to assess morbidity and mortality associated with primary hyperparathyroidism (PHPT).

METHODS

In this population-based retrospective matched cohort study, data linkage of biochemistry, hospital admissions, prescribing, imaging, pathology, and deaths was used to identify patients across the region of Tayside, Scotland, who had PHPT from 1997 to 2019. Cox proportional hazards models and hazards ratios (HR) were used to explore the relationship between exposure to PHPT and several clinical outcomes. Comparisons were made with an age- and gender-matched cohort.

RESULTS

In 11 616 people with PHPT (66.8% female), with a mean follow-up period of 8.8 years, there was an adjusted HR of death of 2.05 (95% CI, 1.97-2.13) for those exposed to PHPT. There was also an increased risk of cardiovascular disease (HR = 1.34; 95% CI, 1.24-1.45), cerebrovascular disease (HR = 1.29; 95% CI, 1.15-1.45), diabetes (HR = 1.39; 95% CI, 1.26-1.54), renal stones (HR = 3.02; 95% CI, 2.19-4.17) and osteoporosis (HR = 1.31; 95% CI, 1.16-1.49). Following adjustment for serum vitamin D concentrations (n = 2748), increased risks for death, diabetes, renal stones, and osteoporosis persisted, but not for cardiovascular or cerebrovascular disease.

CONCLUSION

In a large population-based study, PHPT was associated with death, diabetes, renal stones, and osteoporosis, independent of serum vitamin D concentration.

Primary hyperparathyroidism and fracture probability

The incidence of hip and major osteoporotic fracture was increased in patients with primary hyperparathyroidism even in patients not referred for parathyroidectomy. The risk of death was also increased which attenuated an effect on fracture probabilities. The findings argue for widening the indications for parathyroidectomy in mild primary hyperparathyroidism.

INTRODUCTION

Primary hyperparathyroidism (PHPT) is associated with an increase in the risk of fracture. In FRAX, the increase in risk is assumed to be mediated by low bone mineral density (BMD). However, the risk of death is also increased and its effect on fracture probability is not known.

OBJECTIVE

The aim of this study was to determine whether PHPT affects hip fracture and major osteoporotic fracture risk independently of bone mineral density (BMD) and whether this and any increase in mortality affects the assessment of fracture probability.

METHODS

A register-based survey of patients with PHPT and matched controls in Denmark were identified from hospital registers. The incidence of death, hip fracture, and major osteoporotic fracture were determined for computing fracture probabilities excluding time after parathyroidectomy. The gradient of risk for fracture for differences in BMD was determined in a subset of patients and in BMD controls. The severity of disease was based on serum calcium and parathyroid hormone levels.

RESULTS

We identified 6884 patients with biochemically confirmed PHPT and 68,665 matched population controls. On follow-up, excluding time after parathyroidectomy in those undergoing surgery, patients with PHPT had a higher risk of death (+52%), hip fracture (+48%), and major osteoporotic fracture (+36%) than population controls. At any given age, average 10-year probabilities of fracture were higher in patients with PHPT than population controls. The gradient of fracture risk with differences in BMD was similar in cases and controls. Results were similar when confined to patients not undergoing parathyroidectomy. Fracture probability decreased with the severity of disease due to an increase in mortality rather than fracture risk.

CONCLUSION

The risk of hip and other major osteoporotic fracture is increased in PHPT irrespective of the disease severity. Fracture probability was attenuated due to the competing effect of mortality. The increased fracture risk in patients treated conservatively argues for widening the indications for parathyroidectomy in mild PHPT.

Margin Free Resection Achieves Excellent Long Term Outcomes in Parathyroid Cancer

Long-term outcomes of parathyroid cancer remain poorly documented and unsatisfactory. This cohort includes 25 consecutive parathyroid cancer patients with median follow-up of 10.7 years (range 4.1−26.5 years). Pre-operative work-up in the center identified a suspicion of parathyroid cancer in 17 patients. En bloc resection, including the recurrent laryngeal nerve in 4/17 (23.5%), achieved cancer-free resection margins (R0) in 82.4% and lasting loco-regional disease control in 94.1%. Including patients referred after initial surgery elsewhere, R0 resection was achieved in merely 17/25 (68.0%) of patients. Cancer-positive margins (R1) in 8 patients led to local recurrence in 50%. On multivariate analysis, only margin status prevailed as independent predictor of recurrence free survival (χ2 19.5, p < 0.001). Local excision alone carried a 3.5-fold higher risk of positive margins than en bloc resection (CI95: 1.1−11.3; p = 0.03), and a 6.4-fold higher risk of locoregional recurrence (CI95: 0.8−52.1; p = 0.08). R1-status was associated with an 18.0-fold higher risk of recurrence and redo surgery (CI95: 1.1−299.0; p = 0.04), and a 22.0-fold higher probability of radiation (CI95: 1.4−355.5; p = 0.03). In patients at risk, adjuvant radiation reduced the actuarial risk of locoregional recurrence (p = 0.05). When pre-operative scrutiny resulted in upfront oncological surgery achieving cancer free margins, it afforded 100% recurrence free survival at 5- and 10-year follow-up, whilst failure to achieve clear margins caused significant burden by outpatient admissions (176 vs. 4 days; χ2 980, p < 0.001) and exposure to causes for concern (1369 vs. 0 days; χ2 11.3, p = 0.003). Although limited by cohort size, our study emphasizes the paradigm of getting it right the first time as key to improve survivorship in a cancer with excellent long-term prognosis.