Surgical management of primary hyperparathyroidism in older adults

Primary Hyperparathyroidism in Older Adults: A Narrative Review of the Most Recent Literature on Epidemiology, Diagnosis and Management

BACKGROUND

Primary hyperparathyroidism (PHPT) is a common endocrine disorder among older adults. The aim of this review is to shed light on PHPT, particularly in this age group, in terms of prevalence, clinical manifestations, medical and surgical management, and post-operative complications.

METHODS

Eligible studies were those considering PHPT exclusively in the older population (main databases: PubMed, Medline, Google Scholar and the University Online database). Articles published in the last 10 years (2013-2023) were considered. Eligibility criteria followed the SPIDER (sample, phenomenon of interest, design, evaluation, research type) tool. The methodological quality of the studies was assessed using the Joanna Briggs Institute critical appraisal tool. A total of 29 studies (mainly observational) matched the inclusion criteria.

RESULTS

The prevalence of PHPT is approximately 1 per 100 in the elderly, and it is more common in females. The clinical presentation varies by age and can include osteoporosis, fractures, and neuropsychiatric symptoms. Conservative management can be an option whenever surgery is not indicated or feasible. However, parathyroidectomy (PTX) remains a safe and effective modality in aging populations with improvement to symptoms, bone mineral density, fracture risk, frailty, quality of life, and metabolic derangements. Complication rates are similar in elderly people compared to younger ones, except for mildly longer length of hospital stay and reoperation for those with higher frailty.

CONCLUSION

PHPT is a common yet overlooked and underdiagnosed condition among the older population. The safety and efficacy of PTX in the older population on different levels is now well demonstrated in the literature.

Ex Vivo Intact Tissue Analysis Reveals Alternative Calcium-sensing Behaviors in Parathyroid Adenomas

CONTEXT

The biochemical basis for clinical variability in primary hyperparathyroidism (PHPT) is poorly understood.

OBJECTIVE

This study aimed to define parathyroid tumor biochemical properties associated with calcium-sensing failure in PHPT patients, and to relate differences in these profiles to variations in clinical presentation.

METHODS

Preoperative clinical data from a sequential series of 39 patients undergoing surgery for PHPT at an endocrine surgery referral center in a large, public university hospital were evaluated for correlation to parathyroid tumor biochemical behavior. An intact tissue, ex vivo interrogative assay was employed to evaluate the calcium-sensing capacity of parathyroid adenomas relative to normal donor glands. Tumors were functionally classified based on calcium dose-response curve profiles, and clinical parameters were compared among the respective classes. Changes in the relative expression of 3 key components in the calcium/parathyroid hormone (PTH) signaling axis-CASR, RGS5, and RCAN1-were evaluated as potential mechanisms for calcium-sensing failure.

RESULTS

Parathyroid adenomas grouped into 3 distinct functional classes. Tumors with diminished calcium sensitivity were the most common (18 of 39) and were strongly associated with reduced bone mineral density (P = 0.0009). Tumors with no calcium-sensing deficit (11 of 39) were associated with higher preoperative PTH (P = 0.036). A third group (6/39) displayed a nonsigmoid calcium/PTH response curve; 4 of these 6 tumors expressed elevated RCAN1.

CONCLUSION

Calcium-sensing capacity varies among parathyroid tumors but downregulation of the calcium-sensing receptor (CASR) is not an obligate underlying mechanism. Differences in tumor calcium responsiveness may contribute to variations in PHPT clinical presentation.

Non-surgical management of primary hyperparathyroidism in the aging population

Primary hyperparathyroidism (PHPT) is commonly observed in the aging population, and the average age at diagnosis has increased in the last 20 years. Parathyroidectomy, the only definitive cure for PHPT, is indicated in symptomatic and asymptomatic older PHPT patients with skeletal and renal disease. It is as effective in older patients as it is in younger patients. Nevertheless, older patients may present with comorbidities and greater frailty, leading to the possibility of more complications, higher morbidity and mortality after surgery. This review focuses on the non-surgical clinical management of PHPT in elderly patients. We also summarize the most recent literature regarding the pharmacological management of PHPT to reduce serum calcium levels, to improve bone mineral density or to do both in the aging population.

Cervical re-explorations and proxy survival following parathyroidectomy for primary hyperparathyroidism using Australian administrative data

BACKGROUND

Administrative data may have utility in the impartial assessment of surgical outcomes and rare events. We have used a publicly available sample of the Australian pharmaceutical and health service provision (medical benefits scheme) databases to assess outcomes following parathyroidectomy for primary hyperparathyroidism (PHP).

METHODS

A cohort study using linked pharmaceutical and medical benefits schemes data was performed covering the period 1993-2014. Procedure codes identified participants undergoing parathyroidectomy for PHP and subsequent cervical re-exploration surgery (CRX), and the last service date used as a proxy for survival. Time to CRX and survival were modelled using Kaplan-Meier analysis. Demographic data and the era of parathyroid surgery were managed as covariates for Cox regression survival analyses.

RESULTS

A total of 2165 persons undergoing parathyroidectomy for PHP were identified. Median follow-up was 5.3 years (range 0.2-22). The annual number of parathyroidectomies for PHP increased gradually; 72 individuals underwent CRX (3.3%). The median time to CRX was 152 days (confidence interval 0-396) in 2000-2004 reducing to 47 days (confidence interval 15-78) for the period 2010-2014 (log-rank P = 0.027). The proportion of persons requiring CRX reduced over time from 6.1% in 1997 to 2.1% in 2012 (r²  = 0.5817, P = 0.023). Overall median survival (24.6 years) was poorer when compared with age matched controls (log-rank P = 0.025) but was not associated with CRX or gender.

CONCLUSION

Administrative data can be used for the assessment of surgical outcomes and may be useful for comparisons of surgical performance, and the appraisal of infrequent events. CRX rates following parathyroidectomy for PHP are improving in Australia.

Impaired calcium sensing distinguishes primary hyperparathyroidism (PHPT) patients with low bone mineral density

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.

Primary hyperparathyroidism: review and recommendations on evaluation, diagnosis, and management. A Canadian and international consensus

The purpose of this review is to assess the most recent evidence in the management of primary hyperparathyroidism (PHPT) and provide updated recommendations for its evaluation, diagnosis and treatment. A Medline search of "Hyperparathyroidism. Primary" was conducted and the literature with the highest levels of evidence were reviewed and used to formulate recommendations. PHPT is a common endocrine disorder usually discovered by routine biochemical screening. PHPT is defined as hypercalcemia with increased or inappropriately normal plasma parathyroid hormone (PTH). It is most commonly seen after the age of 50 years, with women predominating by three to fourfold. In countries with routine multichannel screening, PHPT is identified earlier and may be asymptomatic. Where biochemical testing is not routine, PHPT is more likely to present with skeletal complications, or nephrolithiasis. Parathyroidectomy (PTx) is indicated for those with symptomatic disease. For asymptomatic patients, recent guidelines have recommended criteria for surgery, however PTx can also be considered in those who do not meet criteria, and prefer surgery. Non-surgical therapies are available when surgery is not appropriate. This review presents the current state of the art in the diagnosis and management of PHPT and updates the Canadian Position paper on PHPT. An overview of the impact of PHPT on the skeleton and other target organs is presented with international consensus. Differences in the international presentation of this condition are also summarized.