Long-term outcome after parathyroidectomy for lithium-induced hyperparathyroidism

Lithium-associated hypercalcemia and hyperparathyroidism: A systematic review and meta-analysis

OBJECTIVES

We aimed to review and summarise the existing human literature on the association between lithium and hyperparathyroidism.

METHODS

A systematic literature search was carried out according to PRISMA guidelines (last search 27 February 2024), using MEDLINE, Web of Science, Embase and the Cochrane Library. A meta-analysis was performed to determine the prevalence of lithium-associated hypercalcemia (LAHca) in lithium-treated patients.

RESULTS

The pooled prevalence of LAHca based on total calcium and ionised calcium was comparable, at 3.17% and 4.23%, respectively. Calcium, and PTH if the patient is hypercalcaemic, is insufficiently measured in lithium-treated patients in clinical practice. Lithium use is associated with higher calcium and PTH levels, as well as a higher incidence of hyperparathyroidism. There is a high prevalence of multiglandular disease in lithium-associated hyperparathyroidism (LAH), with a pooled prevalence of 51.28%. Parathyroid surgery and cinacalcet are effective treatments for LAH. Regarding lithium discontinuation, there is anecdotal but conflicting evidence suggesting that it can result in the resolution of LAH in selected cases.

CONCLUSIONS

Lithium treatment increases the risk of hyperparathyroidism, a treatable complication with a pooled prevalence of around 4%, compared to 0.5% in the healthy population.

Surgical strategy in lithium-associated hyperparathyroidism: A population-based study

BACKGROUND

The extent of parathyroidectomy (PTX) recommendation in patients with lithium-associated hyperparathyroidism (LAH) remains controversial. The primary objectives of this study were to analyze extent of surgery, complications, and long-term outcomes.

METHODS

A population-based study, including all primary hyperparathyroidism (PHPT) patients who underwent PTX in Sweden between 2008 and 2017. Data on exhibited lithium prescriptions, morbidity, surgical approach, and outcomes were collected from relevant national registers and the Scandinavian Quality Register of Thyroid, Parathyroid, and Adrenal Surgery. Patients with lithium exposure before PTX were defined as having LAH. Descriptive summary statistics and regression models were used to evaluate differences in comorbidities, surgical approach, and outcomes between LAH and PHPT not exposed to lithium (non-LAH).

RESULTS

Lithium exposure was significantly more common among PHPT (n = 202, 2.3%) than in controls (n = 416, 0.5%); OR 5.0 (95% CI 4.2-5.9). The risk of LAH correlated to the length of lithium exposure. In the LAH-group, the surgical procedures were more extensive and associated with a higher risk of postoperative bleeding, wound infections, persistent hypercalcemia, and hypocalcemia that remained after adjustment for the higher percentage of multiglandular disease. However, the cumulative risk of re-admission for PHPT was similar the first years after PTX and primarily elevated for patients with >5 years duration of lithium exposure prior to surgery.

CONCLUSIONS

The findings support the perception of LAH as a complex entity. We recommend a functionally oriented approach, aimed to obtain and maintain normocalcemia for as long as possible, minimizing the risk of permanent hypoparathyroidism, and accepting some risk of recurrence.

Lithium-associated primary hyperparathyroidism:: An evaluation of screening and referral patterns in a southeastern veteran population

BACKGROUND

Long-term lithium therapy has a well-established but under-recognized association with primary hyperparathyroidism. Rates of hypercalcemia, screening for primary hyperparathyroidism, and referral for parathyroidectomy were evaluated among United States veterans on long-term lithium therapy.

METHODS

Patients undergoing chronic long-term lithium therapy (>12 months) were identified from 1999 to 2022. Demographics, long-term lithium therapy duration, post-treatment calcium, parathyroid hormone, creatinine, and vitamin D levels were abstracted. Rates of screening for hypercalcemia (calcium ≥10.2 mg/dL), primary hyperparathyroidism (parathyroid hormone ≥30 pg/mL in the setting of hypercalcemia), referral for parathyroidectomy, and outcomes were evaluated.

RESULTS

A total of 1,356 patients underwent long-term lithium therapy, 514 of whom received chronic long-term lithium therapy. Baseline characteristics of patients with and without post-treatment hypercalcemia were compared. Of 148 patients with post-treatment hypercalcemia, 112 (74.7%) underwent no further evaluation for primary hyperparathyroidism, while 36 (25.3%) patients had a parathyroid hormone level recorded. Although 33 (91.7%) hypercalcemic patients screened positive for primary hyperparathyroidism, only 5 (13%) were referred for parathyroidectomy. Of the 4 patients who underwent parathyroidectomy, mean calcium was 11.2 mg/dL (range 11.1-11.4), and mean parathyroid hormone was 272 pg/mL (range 108-622). Three patients were localized on preoperative imaging, 2 of whom underwent unilateral exploration with cure, with 1 experiencing recurrence at 31 months. The remaining patient who localized preoperatively underwent bilateral exploration and had 2 ipsilateral glands resected and persistence. The patient who did not localize preoperatively underwent bilateral exploration with 3 gland resection and cure.

CONCLUSIONS

Screening for primary hyperparathyroidism and referral for parathyroidectomy are underutilized in United States veterans undergoing chronic long-term lithium therapy. Institutional protocols to standardize screening, surveillance, and referrals to endocrinology/endocrine surgery could benefit this population at increased risk for primary hyperparathyroidism.

Focused parathyroidectomy without intraoperative parathyroid hormone measurement in primary hyperparathyroidism: Still a valid approach?

BACKGROUND

Concern regarding suboptimal cure rates has led to some endocrine surgery units abandoning focused parathyroidectomy for primary hyperparathyroidism in favor of open bilateral neck exploration or making intraoperative parathyroid hormone estimation mandatory in focused parathyroidectomy. This study explores whether focused parathyroidectomy for radiologically localized primary hyperparathyroidism without intraoperative parathyroid hormone is still a valid approach.

METHODS

Retrospective review of a tertiary referral endocrine surgery unit database. All parathyroidectomies for primary hyperparathyroidism over 6 years (2013-2019) were included. Lithium-induced hyperparathyroidism, reoperations, familial disease, and concurrent thyroid surgery were excluded. Characteristics and outcomes for focused parathyroidectomy and open bilateral neck exploration were compared by intention-to-treat and treatment delivered. Persistence and recurrence, conversions and complications were analyzed as endpoints.

RESULTS

A total of 2,828 parathyroidectomies were performed and 2,421 analyzed. By intention to treat there were 1,409 focused parathyroidectomies and 1,012 open bilateral neck explorations. Focused parathyroidectomy patients were younger: 63 vs 66 years (P < .01); however, gender (77%, 79% female), preoperative peak serum calcium (2.72, 2.70 mmol/L [P = .23]), and serum parathyroid hormone (11.5, 11.0 pmol/L [P = .52]) did not differ. In total, 229 (16.3%) focused parathyroidectomies were converted to open bilateral neck exploration. Multiple gland disease was confirmed in 54.5% of converted patients. Median follow-up was 41 months (3-60 months). Persistence or recurrence requiring reoperation totaled 2.2% and did not differ between focused parathyroidectomy and open bilateral neck exploration in either intention to treat or final treatment analyses. Complications occurred in 1.2% of focused parathyroidectomy and 3.2% open bilateral neck exploration (P < .01).

CONCLUSIONS

In experienced hands and with a ready-selective approach to conversion, focused parathyroidectomy based on concordant imaging and without intraoperative parathyroid hormone may deliver equivalent cure rates to open bilateral neck exploration with significantly fewer complications. Focused parathyroidectomy without intraoperative parathyroid hormone should therefore be maintained in the endocrine surgeon's armamentarium.

Lithium-associated hyperparathyroidism

Lithium is a mood stabiliser widely used in the treatment and prophylaxis of mania, bipolar disorders and recurrent depression. Treatment with lithium can give rise to various endocrine and metabolic abnormalities, including thyroid dysfunction, nephrogenic diabetes insipidus and hypercalcaemia. Lithium may induce hypercalcaemia through both acute and chronic effects. The initial acute effects are potentially reversible and occur as a result of lithium's action on the calcium-sensing receptor pathway and glycogen synthase kinase 3, giving rise to a biochemical picture similar to that seen in familial hypocalciuric hypercalcaemia. In the long term, chronic lithium therapy leads to permanent changes within the parathyroid glands by either unmasking hyperparathyroidism in patients with a subclinical parathyroid adenoma or possibly by initiating multiglandular hyperparathyroidism. The latter biochemical picture is identical to that of primary hyperparathyroidism. Lithium-associated hyperparathyroidism, especially in patients on chronic lithium therapy, is associated with increased morbidity. Hence, regular monitoring of calcium levels in patients on lithium therapy is of paramount importance as early recognition of lithium-associated hyperparathyroidism can improve outcomes. This review focuses on the definition, pathophysiology, presentation, investigations and management of lithium-associated hyperparathyroidism.

The Role of Lithium in Management of Endocrine Tumors-A Comprehensive Review

Background: Epidemiological data reveal that treatment with lithium, a mood stabilizer, is associated with decreased incidence and mortality of certain cancer types, such as melanoma. Therefore, repositioning of lithium as an anticancer agent has emerged as a promising strategy in oncology. Since lithium affects the physiology of several endocrine tissues, the goal of this study was to analyze the role of lithium in the pathogenesis and treatment of tumors of the endocrine system. Methods: The databases of PubMed, EMBASE, MEDLINE, were searched from January 1970 through February 2019 for articles including the keywords "lithium and"-"thyroid cancer," "thyroid nodule," "parathyroid adenoma," "parathyroid carcinoma," "pituitary adenoma," "pituitary neuroendocrine tumor," "neuroendocrine tumor," "carcinoid," "adrenal adenoma," "adrenal carcinoma," "pheochromocytoma/paraganglioma." Preclinical in vitro and in vivo studies as well as case series, retrospective cohort studies and prospective trials were selected for the analysis. Results: Treatment with lithium has been associated with a higher prevalence of thyroid enlargement, hypothyroidism and increased calcium levels due to parathyroid adenoma or hyperplasia, as one of the mechanisms of its action is to stimulate proliferation of normal follicular thyroid and parathyroid cells via activation of the Wnt signaling pathway. Supratherapeutic concentrations of lithium decrease the activity of glycogen synthase kinase-3β (GSK-3β), leading to cell cycle arrest in several in vitro cancer models including medullary thyroid cancer (TC), pheochromocytoma/paraganglioma and carcinoid. Growth inhibitory effects of lithium in vivo have been documented in medullary TC xenograft mouse models. Clinically, lithium has been used as an adjuvant agent to therapy with radioactive iodine (RAI), as it increases the residence time of RAI in TC. Conclusion: Patients chronically treated with lithium need to be screened for hypothyroidism, goiter, and hyperparathyroidism, as the prevalence of these endocrine abnormalities is higher in lithium-treated patients than in the general population. The growth inhibitory effects of lithium in medullary TC, pheochromocytoma/paraganglioma and carcinoid were achieved with supratherapeutic concentrations of lithium thus limiting its translational perspective. Currently available clinical data on the efficacy of lithium in the therapy of endocrine tumors in human is limited and associated with conflicting results.

Three Patients with Lithium-Associated Hyperparathyroidism: Literature Review Regarding Medical and Surgical Management

Lithium (Li) carbonate has been established as a mood stabilizer and an efficacious treatment for bipolar disorder since its discovery by Dr. John Cade in 1948. Li interacts significantly with organ systems and endocrine pathways. One of the most challenging side effects of Li to manage is its effect on the parathyroid glands. Dysregulation of parathyroid signaling due to Li results in hypercalcemia due to increased vitamin D₃ generation, increased calcium absorption from the gut, and bone resorption, occasionally resulting in concomitant hypercalciuria. However, hypercalciuria is not a definitive feature for hyperparathyroidism, and normal calcium excretion might be seen in these patients. Hypercalcemia may also result from volume contraction and decreased renal clearance, which are commonly seen in these patients. Anatomically the parathyroid abnormalities can present as single or multiglandular disease. We report 3 cases where the patients developed multiple side effects of Li therapy as well as hypercalcemia due to hyperparathyroidism. The literature is reviewed with regard to medical and surgical management of Li-associated hyperparathyroidism in the context of these 3 presented cases.

Characterization of Calcium Homeostasis in Lithium-Treated Patients Reveals Both Hypercalcaemia and Hypocalcaemia

INTRODUCTION

Prevalence studies demonstrate that a significant proportion of lithium-treated patients develop hypercalcaemia (3-30%). Lithium-associated hyperparathyroidism (LHPT) is poorly defined, and calcium homeostasis may be affected in a more complicated fashion than purely by elevated PTH secretion. The current study aims to examine in detail calcium homeostasis principally with regard to lithium duration.

METHODS

Medical records of 297 lithium-treated patients (193 women, 104 men; median age 58 years) were examined, and information on gender, age, lithium treatment duration and calcium homeostasis was obtained. The median treatment duration with lithium was 16 (1.5-45) years.

RESULTS

A total of 8504 calcium values were retrieved. Before initiation of lithium treatment, serum calcium was on average 2.33 mmol/l (2.02-2.60). During the treatment period, 178 patients (60%) remained normocalcaemic, 102 (34%) developed hypercalcaemia or were strongly suspected of LHPT, 17 (6%) had 3 or more intermittent episodes of hypocalcaemia. Forty-one per cent of patients with suspected or confirmed LHPT had low (<4 mmol) 24-h urine calcium levels. The success rate after 33 parathyroidectomies was 35%, hyperplasia being diagnosed in 75% of extirpated glands.

CONCLUSIONS

The prevalence of hypercalcaemia during lithium treatment is very high. In addition, hypocalcaemic episodes appear to occur frequently, possibly reflecting a more complicated parathyroid dysfunction than previously known. Long-term surgical results are unsatisfactory. LHPT biochemical profile is different from that of primary hyperparathyroidism and is in some ways similar to familial hypocalciuric hypercalcaemia.

Single Centre Experience in Patients with Primary Hyperparathyroidism: Sporadic, Lithium-associated and in Multiple Endocrine Neoplasia

PURPOSE

It is assumed that primary hyperparathyroidism (pHPT) in Multiple Endocrine Neoplasia (MEN) and lithium-associated pHPT (LIHPT) are associated with multiple gland disease (MGD), persistence and recurrence. The studies purpose was to determine frequencies, clinical presentation and outcome of sporadic pHPT (spHPT), LIHPT and pHPT in MEN. Additional main outcome measures were the rates of MGD and persistence/recurrence.

METHODS

Retrospective analysis of medical records of 682 patients with pHPT who had attended the University Hospital of Marburg between 01-01-2004 and 30-06-2013. All patients were sent a questionnaire asking about their history of lithium medication.

RESULTS

Out of 682 patients, 557 underwent primary surgery (532 spHPT, 5 LIHPT, 20 MEN), 38 redo-surgery (31 spHPT, 7 MEN), 55 were in follow-up due to previous surgery (16 spHPT, 1 LIHPT, 38 MEN) and 37 were not operated (33 spHPT, 1 LIHPT, 3 MEN). Primary surgeries were successful in 97.4%, revealed singular adenomas in 92.4%, double adenomas in 2.9% and MGD in 3.4% of the cases. Rates of MGD in MEN1 (82.35%) were significantly higher than in spHPT (3.8%), while there was no significant difference between LIHPT (20%) and spHPT. Rates of persistence/recurrence did not significantly differ due to type of surgery (bilateral/unilateral) or type of HPT (spHPT/LIHPT/MEN).

CONCLUSIONS

History of lithium medication is rare among pHPT patients. While MGD is common in MEN1, rates of MGD, persistence or recurrence in LIHPT were not significantly higher than in spHPT.

Lithium-Associated Hypercalcemia: Pathophysiology, Prevalence, Management

BACKGROUND

Lithium-associated hypercalcemia (LAH) is an ill-defined endocrinopathy. The aim of the present study was to determine the prevalence of hypercalcemia in a cohort of bipolar patients (BP) with and without concomitant lithium treatment and to study surgical outcomes for lithium-associated hyperparathyroidism.

METHODS

Retrospective data, including laboratory results, surgical outcomes and medications, were collected from 313 BP treated with lithium from two psychiatric outpatient units in central Sweden. In addition, data were collected from 148 BP without lithium and a randomly selected control population of 102 individuals. Logistic regression was used to compare odds of hypercalcemia in these respective populations.

RESULTS

The prevalence of lithium-associated hypercalcemia was 26%. Mild hypercalcemia was detected in 87 out of 563 study participants. The odds of hypercalcemia were significantly higher in BP with lithium treatment compared with BP unexposed to lithium (adjusted OR 13.45; 95% CI 3.09, 58.55; p = 0.001). No significant difference was detected between BP without lithium and control population (adjusted OR 2.40; 95% CI 0.38, 15.41; p = 0.355). Seven BP with lithium underwent surgery where an average of two parathyroid glands was removed. Parathyroid hyperplasia was present in four patients (57%) at the initial operation. One patient had persistent disease after the initial operation, and six patients had recurrent disease at follow-up time which was on average 10 years.

CONCLUSION

The high prevalence of LAH justifies the regular monitoring of calcium homeostasis, particularly in high-risk groups. If surgery is necessary, bilateral neck exploration should be considered in patients on chronic lithium treatment. Prospective studies are needed.

The New News about Lithium: An Underutilized Treatment in the United States

Lithium use for the treatment of mood disorders remains quite low, particularly in the United States compared with some European countries. Mogens Schou pioneered the study of lithium for prophylaxis of the recurrent mood disorder and encouraged its greater use. In an effort to further address the appropriate role of this drug, the multiple assets of lithium beyond its well-known antimanic effect are reviewed, and a brief summary of its side effects is outlined. It appears that lithium has positive effects in depression and suicide prevention, cognition, and reducing the incidence of dementia. It increases the length of telomeres and has positive effects in prevention of some medical illnesses. Lithium side-effect burden, especially its association with end-stage renal disease, may be less than many have surmised. New data indicate the importance of long-term prophylaxis after a first manic episode to lessen episode recurrence, allow cognition to recover to normal, and prevent various aspects of illness progression. After a first manic episode, 1 year of randomized treatment with lithium was superior to that of quetiapine, suggesting the importance of having lithium in the treatment regimen. Given the highly recurrent and progressive course of bipolar disorder sometimes even in the face of conventional treatment, the role and enhanced use of lithium deserves reconsideration.

Minimally Invasive Parathyroidectomy Versus Bilateral Neck Exploration for Primary Hyperparathyroidism

Primary hyperparathyroidism is a disease that is caused by excess parathyroid hormone (PTH) secretion from 1 or more of the parathyroid glands. Surgery is the only cure. Traditional surgical management consists of a 4-gland cervical exploration. Development of imaging specific to identification of parathyroid glands and application of the rapid PTH assay to operative management have made more minimal exploration possible. There are distinct advantages and disadvantages of minimally invasive parathyroidectomy (MIP) and bilateral neck exploration (BNE). The advantages of MIP seem to outweigh those of BNE, and MIP has replaced BNE as the operation of choice by many surgeons.

Sporadic multiple parathyroid gland disease--a consensus report of the European Society of Endocrine Surgeons (ESES)

BACKGROUND

Sporadic multiglandular disease (MGD) has been reported in literature in 8-33 % of patients with primary hyperparathyroidism (pHPT). This paper aimed to review controversies in the pathogenesis and management of sporadic MGD.

METHODS

A literature search and review was made to evaluate the level of evidence concerning diagnosis and management of sporadic MGD according to criteria proposed by Sackett, with recommendation grading by Heinrich et al. and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. Results were discussed at the 6th Workshop of the European Society of Endocrine Surgeons entitled 'Hyperparathyroidism due to multiple gland disease: An evidence-based perspective'.

RESULTS

Literature reports no prospective randomised studies; thus, a relatively low level of evidence was achieved. Appropriate surgical therapy of sporadic MGD should consist of a bilateral approach in most patients. Unilateral neck exploration guided by preoperative imaging should be reserved for selected patients, performed by an experienced endocrine surgeon and monitored by intraoperative parathormone assay (levels of evidence III-V, grade C recommendation). There is conflicting or equally weighted levels IV-V evidence supporting that cure rates can be similar or worse for sporadic MGD than for single adenomas (no recommendation). Best outcomes can be expected if surgery is performed by an experienced parathyroid surgeon working in a high-volume centre (grade C recommendation). Levels IV-V evidence supports that recurrent/persistence pHPT occurs more frequently in patients with double adenomas hence in situations where a double adenoma has been identified, the surgeon should have a high index of suspicion during surgery and postoperatively for the possibility of a four-gland disease (grade C recommendation).

CONCLUSIONS

Identifying preoperatively patients at risk for MGD remains challenging, intraoperative decisions are important for achieving acceptable cure rates and long-term follow-up is mandatory in such patients.

The prevalence of lithium-associated hyperparathyroidism in a large Swedish population attending psychiatric outpatient units

OBJECTIVE

This retrospective study determined the prevalence of lithium-associated hyperparathyroidism (LHPT) in 2 geographically defined, equivalent populations in Sweden, with no other selection bias.

METHODS

The medical journals of all patients receiving lithium treatment were examined specifically regarding their biochemistry: calcium, parathyroid hormone (PTH), creatinine, and vitamin D. The condition LHPT was defined biochemically. All patient data were noted, and the prevalence of the condition could thereby be calculated.

RESULTS

A total of 423 patients were included (251 women and 172 men; 3:2), treated over a mean of 13.5 years (range, 1-46 years), aged 19 to 92. 77 patients (18%) were identified with LHTP whose median serum calcium was 2.55 mmol/L and PTH was 99 ng/L. A further 21% showed tendencies toward hypercalcemia. Forty-three percent had vitamin D insufficiency. Five patients (approximately 1%) had undergone parathyroidectomy.

CONCLUSION

The prevalence of LHPT is high and often goes undetected. Vitamin D insufficiency is common as is polypharmacy. Surgery, for unclear reasons, has not been performed extensively, possibly because of limited knowledge of the underlying pathophysiology or surgery's significance. We present standard recommendations on patient management and suggest continual, specific follow-up including the monitoring of calcium, PTH, and vitamin D at least annually. Surgery should be considered with intention to improve psychiatric well-being and provide multiorgan protection.