Increased mortality and morbidity in patients with chronic hypoparathyroidism: A population-based study

Hypoparathyroidism: diagnosis, management and emerging therapies

Hypoparathyroidism is characterized by inadequate parathyroid hormone (PTH) secretion or action and results in hypocalcaemia, and can lead to hyperphosphataemia and hypercalciuria. Most cases of hypoparathyroidism occur as a complication of surgery, with the remainder due to causes including autoimmune disease, genetic causes, infiltrative diseases, mineral deposition or due to abnormalities in serum levels of magnesium. Hypoparathyroidism can cause multisystem disease, with long-term complications resulting from ectopic calcification as well as renal complications with nephrocalcinosis, nephrolithiasis and renal impairment in addition to respiratory, cardiac or neurological manifestations. Conventional therapy consists of oral calcium salts and active vitamin D but it has limitations, including fluctuations in serum levels of calcium and a high pill burden, and can increase the risk of long-term complications. By contrast, PTH replacement therapy can effectively achieve normal serum levels of calcium, and lower serum levels of phosphate. The long-acting PTH analogue, palopegteriparatide, has been shown to normalize urine levels of calcium. In addition, PTH replacement therapy reduces the pill burden. Palopegteriparatide is also associated with improved quality of life in comparison to conventional therapy. This Review summarizes current recommendations regarding the pathophysiology, evaluation and management of hypoparathyroidism and also references the 2022 international hypoparathyroidism guidelines. Palopegteriparatide has now been approved as PTH replacement therapy for hypoparathyroidism. Emerging therapies will also be presented in this Review.

Arrhythmic burden of long-term postsurgical hypoparathyroidism assessed with 24-hour Holter ECG

PURPOSE

Postsurgical hypoparathyroidism is associated with an increased cardiovascular risk, however an increased arrhythmic risk in this population is controversial.

METHODS

Twenty-two postmenopausal women with postsurgical hypoparathyroidism and 22 healthy postmenopausal women of the same age were enrolled. Each subject underwent blood tests, standard 12-lead ECG, 24-hour Holter ECG and echocardiographic measurements. The exclusion criteria were: previous cardiovascular disease, arrhythmias, diabetes mellitus, kidney failure, use of drugs that may interfere with cardiac conduction.

RESULTS

Time since diagnosis of postsurgical hypoparathyroidism was 19.33 ± 8.82 years. As expected, serum calcium and PTH levels were significantly lower in hypoparathyroid patients compared to controls, while phosphorus was higher (all p < 0.05). ECG parameters were within normal values in both groups. A higher number of hypoparathyroid patients had significantly more supraventricular and ventricular premature beats compared to controls (p < 0.05). An index of heart variability, predominantly of parasympathetic activity, such as the root mean square of the difference between successive RR intervals was significantly lower in hypoparathyroid patients compared to controls (21.09 ± 9.84 vs 33.0 ± 17.89 msec, p = 0.009). All the echocardiographic parameters were within the normal limits. The only statistically significant difference between groups was a lower ejection fraction (EF) in the hypoparathyroid group compared to controls (57.5% ± 2.98 vs 64.85% ± 6.09, p < 0.0001). A longer time since diagnosis of hypoparathyroidism was only positively associated with heart rate: B = 0.45, QRS: B = 0.66 and negatively with EF:B = -0.64 (all p < 0.05).

CONCLUSION

24-hour ECG Holter demonstrated an increase in arrhythmia in postmenopausal women with long-term postsurgical hypoparathyroidism in the absence of long QT or cardiac structural abnormalities.

Skeletal health status among patients with chronic hypoparathyroidism: results from the Canadian National Hypoparathyroidism Registry (CNHR)

In the CNHR study, 35% of postmenopausal women had osteoporosis by BMD or fragility fracture, and 4% had both. Three men ≥ 50 had osteoporosis by BMD or fragility fracture (33.3%; n = 3/9). This suggests that close follow-up of skeletal health is necessary in postmenopausal women, and men ≥ 50 with chronic HypoPT.

PURPOSE

Chronic hypoparathyroidism (HypoPT) has been associated with decreased bone turnover and abnormalities in bone mineral density (BMD), microarchitecture, and strength. Current guidelines do not recommend systematic evaluation of skeletal health in patients with chronic HypoPT. Our study assessed skeletal health in pre- and postmenopausal women with chronic HypoPT and adult men.

METHODS

This prospective study enrolled adults with chronic HypoPT from the Canadian National Hypoparathyroidism Registry. Clinical characteristics, bone fractures, biochemistry, and serum bone biomarkers were assessed at baseline. Skeletal health evaluation included assessments of fragility fractures, BMD at lumbar spine (LS), femoral neck (FN), total hip (TH), 1/3 radial sites, trabecular bone score (TBS), and bone biomarkers.

RESULTS

We present the baseline data of the patients enrolled in the registry. We analyzed a total of 101 patients: 18 men, 35 premenopausal, and 48 postmenopausal women. The mean (SD) age at the onset of HypoPT was 40.7 (16.8) years, and the average disease duration was 11.2 (8.6) years. The most common etiology was postsurgical (74.3% vs. 25.7% non-surgical). Most patients received calcium supplements (89%) and active vitamin D (80%) at baseline. No fragility fractures or low BMD were reported in premenopausal women. However, BMD at LS, FN, TH, and TBS were significantly lower in postmenopausal compared to premenopausal women.

CONCLUSIONS

Overall, 35% of postmenopausal women had osteoporosis by BMD or prior fragility fracture, and 4% had both. Three men ≥ 50 years had osteoporosis by BMD or fragility fracture (33.3%; n = 3/9). This study suggests that close follow-up of skeletal health is necessary in postmenopausal women with chronic HypoPT and men ≥ 50 years.

Cardiovascular status in chronic hypoparathyroidism: a systematic cross-sectional assessment in 168 patients

OBJECTIVE

Long-term complications such as renal diseases are well known in patients with chronic hypoparathyroidism (hypoPT), but risk of cardiovascular comorbidity remains less clear. This study comprehensively assessed cardiovascular parameters in hypoPT compared to matched controls.

DESIGN

Cross-sectional cohort study involving 168 patients with chronic hypoPT.

METHODS

Patients underwent electrocardiograms, blood pressure measurements, and echocardiography. A 1:3 propensity score matching was performed with individuals from the German population-based Study of Health in Pomerania (SHIP-TREND) and the "Characteristics and Course of Heart Failure Stages A-B" (STAAB) cohort.

RESULTS

HypoPT showed significantly higher systolic (128 vs 125 mm Hg, P = .02) and diastolic blood pressures (83 vs 77 mm Hg, P < .01). Intake of antihypertensives was similar between groups. The QTc interval was markedly prolonged (438 vs 420 ms, P < .01) with QTc interval prolongation occurring significantly more frequently in hypoPT (24% vs 6%, P < .01). Interestingly, echocardiography revealed significantly lower left ventricular mass index (28 vs 43 g/m2.7, P < .01) and less frequent left ventricular hypertrophy (7%% vs 41%, P < .01) in hypoPT but comparable left ventricular ejection fraction (P = .48). HypoPT patients had higher prevalence of mitral (20 vs 0%, P < .01) and aortic valve stenoses (7 vs 2%, P < .01). Comparison with STAAB confirmed the increased prevalence of arterial hypertension and reduced myocardial mass indices.

CONCLUSIONS

Patients with hypoPT exhibit a higher prevalence of QTc interval prolongation despite established therapy and an increased incidence of hypertension. Conversely, echocardiography revealed lower left ventricular mass and less frequent left ventricular hypertrophy in hypoPT, but higher prevalence of valve stenosis. Regular monitoring of hypertension, QTc interval prolongation, and valve stenosis is recommended to reduce the risk of cardiovascular diseases.

CLINICAL TRIAL REGISTRATION NUMBER

NCT05585593.

Significance of QTc Interval in Chronic Hypoparathyroidism and its Correlates

CONTEXT

Hypocalcemia predisposes patients with chronic hypoparathyroidism (cHypoPT) to an increased risk of QTc prolongation and life-threatening arrhythmias. Information on clinical and biochemical correlates of QTc in cHypoPT is limited.

OBJECTIVE

To assess the significance of QTc interval in chronic hypoparathyroidism and its correlates.

METHODS

This was an observational cohort study at a tertiary care center. Eighty-eight nonsurgical patients with cHypoPT (mean age 44.1 ± 15.4 years, 45 males) were assessed for QTc interval and its possible correlates including arrhythmic symptoms (palpitation/giddiness/syncope), serum total calcium, phosphate, 25(OH)D, and intact parathyroid hormone.

RESULTS

The mean QTc in the HypoPT cohort was 428 ± 34 ms with 13.6% having prolonged QTc. There was a significant inverse correlation between QTc interval and serum total calcium measured on the same day (r = -0.43, P < .001). The mean serum total calcium was significantly lower in patients with prolonged QTc (7.05 ± 1.94 vs 8.49 ± 1.01 mg/dL, P = .02). Of patients with cHypoPT 21.6% had arrhythmic symptoms. They had significantly higher mean QTc (P = .02) and also tended to have lower mean serum total calcium during follow-up (P = .06). In multivariable regression, female gender, higher current age, higher body mass index, and low serum total calcium showed significant association with prolonged QTc. For every mg/dL decrease in serum total calcium, QTc increased by 13 ms. Receiver operating characteristic analysis revealed serum total calcium at cut-off of 8.3 mg/dL discriminated prolonged QTc with area under the curve being 0.72 (95% CI 0.51, 0.93).

CONCLUSION

One-fifth of patients with cHypoPT had arrhythmic symptoms and a significant proportion had prolonged QTc. This highlights the need for close monitoring of patients with cHypoPT for arrhythmic symptoms and QTc prolongation. The serum total calcium should be maintained to at least 8.3 mg/dL to minimize the risk of potentially life-threatening arrhythmia in cHypoPT.

Increased arterial stiffness in normotensive individuals with hypoparathyroidism

Hypoparathyroidism is the inability of parathyroid hormone (PTH) to maintain calcium homeostasis. Patients with post-surgical hypoparathyroidism may have an increased risk of mortality; there is clinical and molecular evidence of the effects of this condition on the cardiovascular system. The aim of this study was to evaluate arterial stiffness by measuring the carotid-femoral pulse wave velocity (PWV) in post-surgical hypoparathyroidism patients. A cross-sectional study was conducted with 30 post-surgical hypoparathyroidism patients and 25 volunteers from the Endocrinology Outpatient Clinic of the Medical School. The SphygmoCor system was used to evaluate arterial stiffness by analyzing the PWV. The mean ages of the hypoparathyroidism (50.4 years) and control individuals (49.6 years) were similar. The mean PWVs were 8.7 and 7.5 m/s in the Hypoparathyroidism and Control groups, respectively (p-value = 0.084). Considering only normotensive patients, PWV was statistically higher in the Hypoparathyroidism Group (7.6 versus 6.5 m/s; p-value = 0.039). For this group, serum ionized calcium, phosphorus, and the calcium x phosphorus product levels were positively associated to PWV. Hypoparathyroidism increases arterial stiffness as assessed by PWV. Serum ionized calcium, phosphorus, and the calcium x phosphorus product are affected. A more effective investigative and therapeutic approach for patients with hypoparathyroidism can help control cardiovascular risk.

Impaired renal function in patients with permanent hypoparathyroidism after thyroidectomy: analysis of a nationwide cohort in Spain

PURPOSE

We aimed to assess the decline in renal function in patients with chronic postoperative hypoparathyroidism.

METHODS

We performed a multicenter, retrospective cohort study including patients with chronic hypoparathyroidism lasting ≥ 3 years. We evaluated the changes in serum creatinine and estimated glomerular filtration rate (eGFR) before surgery and at the last visit. Changes were evaluated in absolute value (ΔeGFR = eGFR at last visit - eGFR before thyroidectomy) and corrected for time (ΔeGFR/yr = ΔeGFR / time in years).

RESULTS

We included 236 patients with hypoparathyroidism (85.6% women, median age 47 [37-58] years, median time of follow-up 7.3 [5.0-11.0] years), and 458 control subjects with similar age, gender, and time of follow-up. Before thyroidectomy we found no significant differences in serum creatinine levels or eGFR between patients and controls. At the end of follow-up, ΔeGFR and ΔeGFR/yr in the patients with hypoparathyroidism were -4.87 (-17.0-0.00) ml/min/1.73 m2 and -0.68 (-2.31-0.00) ml/min/1.73 m2 per year, respectively, whereas in the control subjects these changes were 0.00 (-10.10-4.00) ml/min/1.73 m2 (P < 0.001), and 0.00 (-1.34-0.54) ml/min/1.73 m2 per year (P < 0.001). In multivariable regression analysis the annual eGFR decline in patients with hypoparathyroidism was related to age (P < 0.001), eGFR before thyroidectomy (P < 0.001), and incident nephrolithiasis (P = 0.028).

CONCLUSION

The decline in renal function over time is significantly higher in patients with chronic hypoparathyroidism after thyroidectomy compared to thyroidectomized patients without hypoparathyroidism. Age, preoperative eGFR and nephrolithiasis are the main determinants of renal function loss in these patients.

Long-term kidney outcomes in patients with permanent hypoparathyroidism after total thyroidectomy for benign disease: A population-based study

BACKGROUND

Permanent hypoparathyroidism is a significant complication after total thyroidectomy. This study aimed to evaluate the long-term impact of postoperative permanent hypoparathyroidism on kidney outcomes.

METHODS

Data of patients undergoing total thyroidectomy from 1999 to 2014 were retrieved. The estimated glomerular filtration rate was determined from serum creatinine results. Permanent hypoparathyroidism was defined as requiring oral calcium and vitamin D supplements postoperatively for at least 6 months. The primary outcome was a sustained decline in the estimated glomerular filtration rate from baseline by ≥50%. Secondary outcomes were end-stage kidney disease (a composite of sustained estimated glomerular filtration rate <15 mL/min/1.73 m2, need for dialysis, and kidney transplantation) and rate of estimated glomerular filtration rate decline. Patients with and without permanent hypoparathyroidism were compared. Multivariable Cox regression analysis was performed to identify independent risk factors for sustained estimated glomerular filtration rate decline by ≥50%.

RESULTS

In total, 3,245 patients were eligible for analysis; 418 patients (12.9%) had permanent hypoparathyroidism. Upon median follow-up of 11.6 years, more patients with permanent hypoparathyroidism had a sustained decline in estimated glomerular filtration rate from baseline by ≥50% compared to those without (15.6% vs 6.9%, P < .001). Similar findings were obtained on Kaplan-Meier analysis (P < .001). Permanent hypoparathyroidism was an independent risk factor for sustained estimated glomerular filtration rate decline by ≥50% (adjusted hazard ratio 2.77, P < .001). Other risk factors included age, preoperative estimated glomerular filtration rate <60 mL/min/1.73m2, and diabetes mellitus. Patients with permanent hypoparathyroidism had a more rapid estimated glomerular filtration rate decline (-1.60 vs -0.70 mL/min/1.73 m2/year, difference -0.91 mL/min/1.73m2/year, P < .001).

CONCLUSION

Patients with postsurgical permanent hypoparathyroidism were at greater risk of renal impairment. Further research is warranted to improve the identification and preservation of parathyroid glands during thyroidectomy to minimize patient morbidity.

Hypoparathyroidism update

PURPOSE OF REVIEW

Since the release of the 2022 Second International Workshop Evaluation and Management of Hypoparathyroidism Summary Statement and Guidelines, updates and advances are now available in the cause, complications, and treatment of adult chronic hypoparathyroidism (hypoPTH). This review aims to highlight these new findings and implications to patient care.

RECENT FINDINGS

Postsurgical hypoparathyroidism remains the most common cause, immune-related hypoparathyroidism from checkpoint inhibitors is an emerging autoimmune cause. In a large retrospective cohort study of thyroidectomies, incident fracture was lower, particularly in the vertebra, in the hypoPTH cohort, compared with postthyroidectomy control group. Hypercalciuria increases risk for renal calculi in hypoPTH independent of disease duration and treatment dose. Quality of life is impaired in hypoPTH patients on conventional therapy, improvement was noted post-PTH replacement. TranCon PTH phase 3 RCT reported eucalcemia with reduced renal calcium excretion, normalization of bone turn-over markers, stable BMD and improved quality of life.

SUMMARY

HypoPTH is a chronic disease associated with significant morbidity and poor Quality of Life. Awareness of treatment targets and follow-up investigations can alleviate patient anxiety regarding over-treatment and under-treatment. Progress in long-acting PTH replacement strategies might provide accessible, feasible alternatives to conventional therapy in brittle hypoPTH patients.

Presentation of hypoparathyroidism in Italy: a nationwide register-based study

PURPOSE

We sought to assess the clinical presentation of hypoparathyroidism (HypoPT) in Italy.

METHODS

We performed a nationwide study retrieving data from the hospital discharge ICD-9 codes database of the Italian Health Ministry, from 2007 through 2017. The codes corresponding to diagnosis of cardiovascular disease, cancer, infection, renal failure, psychiatric disease, upper airway tract infection and pneumonia, seizures, nephrolithiasis, cognitive impairment, cerebral calcifications, skin disorders, fracture, and cataract were retrieved when associated with the diagnosis of HypoPT (252.1). We excluded codes corresponding to diagnoses of cancer of the neck region. In-hospital mortality rate was calculated. We retrieved the same data from an age- and sex-matched non-HypoPT control population.

RESULTS

Fourteen thousand five hundred seventy-nine hospitalizations for HypoPT and controls were analyzed. Hospitalization for cardiovascular disease, cancer, infection, renal failure, seizures, nephrolithiasis, cerebral calcifications (p < 0.0001), and cognitive impairment (p < 0.05) were more common in HypoPT compared to controls. Mean age of HypoPT with cardiovascular disease, cancer, and renal failure was younger compared to controls (p < 0.0001). The OR of hospitalization for cardiovascular disease, cancer, renal failure, seizures (OR 2, 40, 48  and 1.6, respectively), and nephrolithiasis (OR 1.6) were significant in HypoPT compared to non-HypoPT. The OR of hospitalization for infection and cognitive impairment were significant only in HypoPT women (OR 1.3 and 2.3, respectively). In-hospital mortality rate was lower in HypoPT vs controls (0.5% and 3.7%; p < 0.0001).

CONCLUSION

Hospitalizations for cardiovascular disease, cancer, and renal failure are more prevalent and occur at a younger age in HypoPT vs non-HypoPT. Hospitalizations for seizures and nephrolithiasis are frequent in HypoPT; those for infection and cognitive impairment are more common in HypoPT women.

Long-term complications of permanent hypoparathyroidism in adults: prevalence and associated factors

INTRODUCTION

Patients with Chronic hypoparathyroidism (CHPT) receiving conventional treatment are exposed to several long-term complications including basal ganglia calcifications, posterior subcapsular cataract, kidney stones, and renal insufficiency. The aim of this study was to assess the prevalence and the associated factors of these complications in patients with CHPT.

METHODS

We conducted a cross-sectional study including 58 patients with CHPT. All participants underwent physical examination, biochemical assessment (total serum calcium, serum phosphorus, serum albumin, intact-PTH, serum magnesium, 25-hydroxy-vitamin D, serum creatinine, thyroid stimulating hormone (TSH), and 24-hour urinary calcium), slit lamp examination, brain computed tomography scan (CT-scan), and renal ultrasound.

RESULTS

Participants had a mean age of 52.6 ± 16.4 years and a gender ratio (women/men) of 3.5. Fahr syndrome, cataract, urolithiasis, and renal failure were found in 55%, 62%, 12%, and 17% of cases, respectively. CHPT duration >15 years (Adjusted-OR = 43.1, 95-CI: 2.63-703.06, p = 0.008) and poor adherence to treatment (Adjusted-OR = 8.04, 95%-CI: 1.52-42.42, p = 0.014) were independently associated with the risk of Fahr syndrome. Age >55 years (adjusted-OR = 5.07, 95-CI: 1.10-23.42, p = 0.037), disease duration >15 years (adjusted-OR = 20.21, 95-CI: 1.54-265.84, p = 0.022), and magnesium level <0.8 mmol/l (adjusted-OR = 36.46, 95-CI: 3.75-354.08, p = 0.002) were independently associated with the risk of subcapsular cataract. Only hypercalciuria (Adjusted-OR = 21.27, 95-CI: 2.31-195.91, p = 0.007) was an independent risk factor for kidney stones. Renal failure was not associated with kidney stones (p = 1). However, creatinine clearance was negatively correlated with age (r = -0.784; p < 10-3) and disease duration (r = -0.352; p = 0.007).

CONCLUSION

Our results revealed high prevalences of neurological, ocular, and renal complications in patients with CHPT and emphasized the importance of regular biological monitoring, therapeutic adjustments, screening, and adherence to treatment in the prevention of these complications.

Economic burden of patients with post-surgical chronic and transient hypoparathyroidism in the United States examined using insurance claims data

BACKGROUND

Hypoparathyroidism (HP) is a rare endocrine disease commonly caused by the removal or damage of parathyroid glands during surgery and resulting in transient (tHP) or chronic (cHP) disease. cHP is associated with multiple complications and comorbid conditions; however, the economic burden has not been well characterized. The objective of this study was to evaluate the healthcare resource utilization (HCRU) and costs associated with post-surgical cHP, using tHP as a reference.

METHODS

This analysis of a US claims database included patients with both an insurance claim for HP and thyroid/neck surgery between October 2014 and December 2019. cHP was defined as an HP claim ≥ 6 months following surgery and tHP was defined as only one HP claim < 6 months following surgery. The cHP index date was the first HP diagnosis claim following their qualifying surgery claim, whereas the tHP index date was the last HP diagnosis claim following the qualifying surgery claim. Patients were continuously enrolled at least 1 year pre- and post-index. Patients' demographic and clinical characteristics, all-cause HCRU, and costs were descriptively analyzed. Total all-cause costs were calculated as the sum of payments for hospitalizations, emergency department, office/clinic visits, and pharmacy.

RESULTS

A total of 1,406 cHP and 773 tHP patients met inclusion criteria. The average age (52.1 years cHP, 53.5 years tHP) and representation of females (83.2% cHP, 81.2% tHP) were similar for both groups. Neck dissection surgery was more prevalent in cHP patients (23.6%) than tHP patients (5.3%). During the 1-2 year follow-up period, cHP patients had a higher prevalence of inpatient admissions (17.4%), and emergency visits (26.0%) than the reference group -tHP patients (14.4% and 21.4% respectively). Among those with a hospitalization, the average number of hospitalizations was 1.5-fold higher for cHP patients. cHP patients also saw more specialists, including endocrinologists (28.7% cHP, 15.8% tHP), cardiologists (16.7% cHP, 9.7% tHP), and nephrologists (4.6% cHP, 3.3% tHP).

CONCLUSION

This study demonstrates the increased healthcare burden of cHP on the healthcare system in contrast to patients with tHP. Effective treatment options are needed to minimize the additional resources utilized by patients whose HP becomes chronic.

Coronary calcium score in patients with post-surgical hypoparathyroidism

Objective

This study aimed to evaluate the cardiovascular risk of patients with post-surgical hypoparathyroidism through coronary calcium score (CACS) evaluation andcardiovascular risk calculators.

Subjects and methods

Patients with post-surgical hypoparathyroidism (HG = 29) were compared to a control group (CG = 29), matched by sex and age. Demographic and clinical data were captured by a questionnaire or patient files. Both groups performed a thoracic-computed tomography to evaluate the CACS and the cardiovascular risk was calculated by two risk calculators.

Results

In the HG, the supplementation of calcium varied between 500 to 2,000 mg/day and the mean calcitriol was 0.5 ± 0.29 mcg/day. The mean serum calcium and phosphorus were 8.32 ± 0.68 and 4.92 ± 0.87 mg/dL, respectively, and in the range recommended for hypoparathyroidism. The Brazilian Society of Cardiology's risk calculator showed a difference among groups, with no patient in the HG with low risk, but the CACS was similar. A positive CACS in the HG was associated with obesity and high BMI but not with calcium and/or vitamin D supplementation.

Conclusion

In conclusion, patients with hypoparathyroidism did not show increased CACS, and it was not related to supplementation.

Hypoparathyroidism and mortality after total thyroidectomy: A nationwide matched cohort study

OBJECTIVE

Total thyroidectomy (TT) carries a risk of hypoparathyroidism (hypoPT). Recently, hypoPT has been associated with higher overall mortality rates. We aimed to evaluate the frequency of hypoPT and mortality in patients undergoing TT in Denmark covering 20 years.

DESIGN

Retrospective Cohort study.

PATIENTS AND MEASUREMENTS

Using population-based registries, we identified all Danish individuals who had undergone TT between January 1998 and December 2017. We included a comparison cohort by randomly selecting 10 citizens for each patient, matched on sex and birth year. HypoPT was defined as treatment with active vitamin D after 12 months postoperatively. We used cumulative incidence to calculate risks and Cox regression to compare the rate of mortality between patients and the comparison cohort. We evaluated patients in different comorbidity groups using the Charlson Comorbidity Index and by different indications for surgery.

RESULTS

7912 patients underwent TT in the period. The prevalence of hypoPT in the study period was 16.6%, 12 months postoperatively. After adjusting for potential confounders the risk of death due to any causes (hazard ratio; 95% confidence intervals) following TT was significantly increased (1.34; 1.15-1.56) for patients who developed hypoPT. However, subgroup analysis revealed mortality was only increased in malignancy cases (2.48; 1.99-3.10) whereas mortality was not increased when surgery was due to benign indications such as goitre (0.88; 0.68-1.15) or thyrotoxicosis (0.86; 0.57-1.28).

CONCLUSIONS

The use of active vitamin D for hypoPT was prevalent one year after TT. Patients with hypoPT did not have an increased risk of mortality following TT unless the indication was due to malignancy.

Features of patients and fracture risk in hypoparathyroidism; a single center study

PURPOSE

Patients with hypoparathyroidism (hypoPT) have low bone turnover and high bone mineral density (BMD). However, data on fracture risk are conflicting. The objectives of this study were: 1. To describe clinical/biochemical characteristics of hypoPT patients followed at a single medical center. 2. To identify postsurgical hypoPT patients and investigate their fracture rate compared with gender/age-matched post-surgical normocalcemic patients.

METHODS

Retrospective analysis of patient's medical records treated at the tertiary medical center in 2010-2021 identified by computerized medical database search.

RESULTS

The cohort included 133 patients (91% women, mean age 64 ± 13 years) of whom 105 (79%) had post-thyroidectomy hypoparathyroidism and the remainder had an autoimmune/idiopathic/other etiology. Mean follow-up time was 21 ± 12 and 27 ± 12 years, respectively. The control group included 142 post-thyroidectomy patients without hypoparathyroidism. Patients in the postsurgical hypoparathyroidism group were older and had higher calcium and PTH levels at diagnosis than the non-surgical hypoPT patients. Comparing the postsurgical hypoPT and postsurgical normocalcemic control patients revealed a significantly higher BMD in the hypoPT group. Yet, fracture rates were 31% in the postsurgical hypoparathyroidism group and 21% in the control group (P = 0.1) over a similar median follow-up period (17 and 18.4 years, respectively). In both groups the most common fracture site was the spine (50% and 70%, respectively; p = 0.33), mainly nonclinical morphometric fractures. Higher phosphorus blood level was associated with increased fracture risk.

CONCLUSIONS

The relatively high BMD in patients with postsurgical hypoparathyroidism is not associated with lower fracture risk. Silent morphometric fractures are quite common in this group of patients.

Incident comorbidities in patients with chronic hypoparathyroidism after thyroidectomy: a multicenter nationwide study

Purpose

Population-based and registry studies have shown that chronic hypoparathyroidism is accompanied by long-term complications. We aimed to evaluate the risk of incident comorbidity among patients with chronic postsurgical hypoparathyroidism in real-life clinical practice in Spain.

Methods

We performed a multicenter, retrospective cohort study including patients with chronic postsurgical hypoparathyroidism lasting ≥3 years with at least a follow-up visit between January 1, 2022 and September 15, 2023 (group H). The prevalence and incidence of chronic complications including chronic kidney disease, nephrolithiasis/nephrocalcinosis, hypertension, dyslipidemia, diabetes, cardiovascular disease, central nervous system disease, mental health disorders, eye disorders, bone mineral density alterations, fracture and cancer were evaluated. Patient data were compared with a group of patients who did not develop hypoparathyroidism, matched by gender, age, and follow-up time after thyroidectomy (group NH).

Results

We included 337 patients in group H (median [IQR] age, 45 [36-56] years; median time of follow-up, 8.9 [6.0-13.0] years; women, 84.3%) and 669 in group NH (median age, 47 [37-55] years; median time of follow-up, 8.0 [5.3-12.0] years; women, 84.9%). No significant differences were found in the prevalence of comorbidities at the time of thyroidectomy between both groups. In multivariable adjusted analysis, patients with chronic hypoparathyroidism had significantly higher risk of incident chronic kidney disease (OR, 3.45; 95% CI, 1.72-6.91; P<0.001), nephrolithiasis (OR, 3.34; 95% CI, 1.55-7.22; P=0.002), and cardiovascular disease (OR, 2.03; 95% CI, 1.14-3.60; P=0.016), compared with patients without hypoparathyroidism. On the contrary, the risk of fracture was decreased in patients with hypoparathyroidism (OR, 0.09; 95% CI, 0.01-0.70; P=0.021).

Conclusion

This study demonstrates that, in the clinical practice of Spanish endocrinologists, a significant increase in the risk of chronic kidney disease, nephrolithiasis and cardiovascular disease, as well as a reduction in the risk of fractures is detected. These results are of interest for the development of new clinical guidelines and monitoring protocols for patients with hypoparathyroidism.

Chronic hypoparathyroidism is associated with increased cortical bone density evaluated using high-resolution peripheral quantitative computed tomography

PURPOSE

This cross-sectional study aimed to assess bone mineral density (BMD), bone microarchitecture and fracture prevalence in women with chronic postsurgical hypoparathyroidism (hypoPT).

METHODS

Twenty-seven women with postsurgical hypoPT and 44 age-matched healthy women were included. Dual-energy X-ray absorptiometry was used to evaluate areal BMD and vertebral fracture assessment. High-resolution peripheral quantitative computed tomography assessed microarchitecture and volumetric BMD at the distal radius and tibia. Biochemical parameters, including fibroblast growth factor 23, C-terminal cross-linking telopeptide of type I collagen (ICTP), and procollagen type I N-terminal propeptide (P1NP), were also measured. Previous low-impact fractures were assessed and the 10-year fracture risk was estimated using the FRAX tool for the Brazilian population.

RESULTS

No participant had prevalent clinical fractures, and both groups showed low risk for major and hip based on FRAX tool, but two hypoPT patients had moderate to severe morphometric vertebral fractures. Women with hypoPT had increased aBMD in the lumbar spine, femoral neck and total hip (p < 0.05) and higher cortical vBMD in the radius (p = 0.020) and tibia (p < 0.001). Trabecular bone was not affected. Both P1NP and ICTP suggested low bone turnover rates, but no significant correlation was observed between bone density or microstructure and any of the biochemical parameters.

CONCLUSIONS

The prevalence of fragility fractures was low in HypoPT women and compatible with low fracture risk estimated by the FRAX tool. Patients had a higher aBMD and cortical vBMD than those of healthy control women, but the association with decreased bone turnover remains unclear.

Renal complications in chronic hypoparathyroidism - a systematic cross-sectional assessment

Context

Although renal long-term complications are acknowledged in chronic hypoparathyroidism (HPT), standardized investigations are scarce.

Objective

To systematically investigate renal complications and their predictors in hypoparathyroid patients compared to matched individuals.

Design

Prospective observational study in 161 patients with chronic HPT.

Methods

Patients received renal ultrasound, clinical and laboratory assessments. An individual 1:3 matching with participants from the German population-based Study of Health in Pomerania was performed.

Results

Of 161 patients (92% postoperative HPT), prevalence of eGFR <60ml/min/1.73m2 was 21%, hypercalciuria 41%. Compared to healthy individuals, HPT patients had a significantly lower eGFR (74.2 vs. 95.7 ml/min/1.73m², p<0.01). Renal ultrasound revealed calcifications in 10% (nephrocalcinosis in 7% and calculi in 3%). Patients with renal calcifications had higher levels of 24-hour urine calcium excretion (8.34 vs. 5.08 mmol/d, p=0.02), spot urine calcium excretion (4.57 vs. 2.01 mmol/L, p=0.01) and urine calcium-to-creatinine ratio (0.25 vs. 0.16, p<0.01) than patients without calcifications. Albumin-corrected calcium, phosphate, calcium-phosphate product, 25-hydroxyvitamin D in serum, eGFR, daily calcium intake or disease duration were not significantly different between these two groups. Including patients receiving rhPTH therapy, a lower serum phosphate concentration (odds ratio 1.364 [95% confidence interval (CI) 1.049-1.776], p<0.05) and a longer disease duration of HPT (odds ratio 1.063 [95% CI 1.021-1.106], p<0.01) were significant predictors for renal calcifications. Excluding patients receiving rhPTH therapy, a higher 24-hour urine calcium excretion (odds ratio 1.215 [95% CI 1.058-1.396], p<0.01) was a significant predictor for renal calcifications but not serum magnesium or disease duration.

Conclusions

Prevalence of impaired renal function among patients with chronic HPT is increased and independent from visible renal calcifications. Depending on exclusion of patients with rhPTH therapy, regression analysis revealed disease duration and serum phosphate or disease duration and 24-hour urinary calcium excretion as predictors for renal calcifications.

Clin Trials Identifier

NCT05585593.

Fracture Risk in Patients with Hypoparathyroidism

PURPOSE OF REVIEW

To summarize the recently published scientific evidence on fracture risk in hypoparathyroidism.

RECENT FINDINGS

Hypoparathyroidism is characterized by a low bone turnover and a high bone mineral density. Data on fracture risk are sparse and due to the rarity of the disease, available studies have only been able to include relatively few patients. Risk of non-vertebral fractures does not seem to be affected to any major degree, although epidemiological studies suggest a decreased risk of fractures at the humerus in postsurgical hypoparathyroidism, whereas an increased risk of fractures at the upper arm has been shown in non-surgical hypoparathyroidism. Several, but not all, studies have also pointed towards an increased risk of vertebral fractures, especially in non-surgical hypoparathyroidism. Fractures at the appendicular skeleton do not seem to be of specific concern in hypoparathyroidism, but emerging data suggest an increased risk of vertebral fractures, which needs to be clarified further in upcoming studies.

Risk of Fractures in Thyroid Cancer Patients With Postoperative Hypoparathyroidism: A Nationwide Cohort Study in Korea

Postoperative hypoparathyroidism (PO-hypoPT) is an uncommon complication of total thyroidectomy in thyroid cancer patients. Although long-term hypoPT causes characteristic changes in bone metabolism, the risk of fractures in hypoPT remains inconclusive. We investigated the risk of fractures in Korean thyroid cancer patients with PO-hypoPT. This was a retrospective cohort study using data from the Korea Central Cancer Registry and Korean National Health Insurance Service. We analyzed 115,821 thyroid cancer patients aged ≥18 years, who underwent total thyroidectomy between 2008 and 2016. The risk of any fractures, including vertebral, hip, humerus, and wrist fractures, according to parathyroid function after total thyroidectomy, was analyzed using the multivariable Cox proportional hazard model. The PO-hypoPT and preserved parathyroid function groups included 8789 (7.6%) and 107,032 (92.4%) patients, respectively. Over a mean follow-up duration of 4.8 years, 159 (1.8%) and 2390 (2.2%) fractures occurred in the PO-hypoPT and preserved parathyroid function groups, respectively. The risk of any fractures was significantly lower in the PO-hypoPT group than in the preserved parathyroid function group (hazard ratio [HR] = 0.83; 95% confidence interval [CI] 0.70-0.98; p = 0.037) after adjusting for confounders. Regarding the fracture site, only the risk of vertebral fractures was significantly lower in the PO-hypoPT group compared with the preserved parathyroid function group (HR = 0.67; 95% CI 0.47-0.96; p = 0.028) after adjusting for confounders. Subgroup analyses showed that bone mineral density measurements and calcium supplementation interacted with the relationship between PO-hypoPT and the risk of any fractures (p for interactions = 0.010 and 0.017, respectively). PO-hypoPT was associated with a lower risk of fractures in thyroid cancer patients, especially at the vertebra. The relatively low bone turnover caused by PO-hypoPT and appropriate management for PO-hypoPT with active vitamin D and calcium may prevent the deterioration of skeletal health in thyroid cancer patients who can easily be exposed to long-term overtreatment with levothyroxine. © 2023 American Society for Bone and Mineral Research (ASBMR).

The risk of chronic kidney disease development in adult patients with chronic hypoparathyroidism treated with rhPTH(1-84): A retrospective cohort study

OBJECTIVE

This study assessed the risk of developing chronic kidney disease (CKD) and decline in estimated glomerular filtration rate (eGFR) over a period of up to 5 years in adult patients with chronic hypoparathyroidism treated with recombinant human parathyroid hormone (1-84) (rhPTH[1-84]) compared with a historical control cohort of patients not treated with rhPTH(1-84).

DESIGN

Retrospective cohort study of patients with chronic hypoparathyroidism treated with rhPTH(1-84) derived from the REPLACE (NCT00732615), RELAY (NCT01268098), RACE (NCT01297309) and HEXT (NCT01199614, and its continuation study NCT02910466) clinical trials and a historical control cohort who did not receive PTH selected from an electronic medical record database.

PATIENTS

One hundred and eighteen patients treated with rhPTH(1-84) and 497 patient controls.

MEASUREMENTS

Incident CKD was defined as ≥2 eGFR measurements <60 ml/min/1.73 m² ≥3 months apart during the study and a sustained eGFR decline of ≥30% from baseline.

RESULTS

Over the 5-year period, Kaplan-Meier analyses showed that rhPTH(1-84)-treated patients had a significantly lower risk of developing CKD (log-rank p = .002) and a lower risk for a sustained eGFR decline ≥30% from baseline (log-rank p < .001) compared with patients in the control cohort. In adjusted analyses, patients in the rhPTH(1-84)-treated cohort had a 53% lower risk of developing CKD (hazard ratio [HR], 0.47; 95% confidence interval [CI], 0.25-0.87) and a 65% lower risk for sustained eGFR decline ≥30% from baseline (HR, 0.35; 95% CI, 0.13-0.89) compared with controls.

CONCLUSIONS

Patients with chronic hypoparathyroidism treated with rhPTH(1-84) in long-term clinical trials had a significantly lower risk of developing CKD compared with patients in a historical control cohort not treated with rhPTH(1-84).

Association of Serum Calcium and Phosphate With Incident Cardiovascular Disease in Patients With Hypoparathyroidism

The pathophysiological basis for the increased incidence of cardiovascular disease in patients with chronic hypoparathyroidism is poorly understood. To evaluate associations between levels of albumin-corrected serum calcium, serum phosphate, and calcium-phosphate product with the odds of developing cardiovascular events in patients with chronic hypoparathyroidism with ≥1 calcitriol prescription, we conducted a retrospective nested case-control study of patients who developed a cardiovascular event and matched controls without an event. The primary outcome was the instance of cardiovascular events. An electronic medical record database was used to identify 528 patients for the albumin-corrected serum calcium analysis and 200 patients for the serum phosphate and calcium-phosphate product analyses. Patients with ≥67% of albumin-corrected serum calcium measurements outside the study-defined 2.00 to 2.25 mmol/L (8.0 to 9.0 mg/100 ml) range had 1.9-fold higher odds of a cardiovascular event (adjusted odds ratio, 95% confidence interval 1.89, 1.10 to 3.25) compared with patients with <33% of calcium measurements outside the range. Likewise, patients with any serum phosphate measurements above 0.81 to 1.45 mmol/L (2.5 to 4.5 mg/100 ml) had 3.3-fold higher odds (3.26; 1.24 to 8.58), and those with any calcium-phosphate product measurements above 4.40 mmol²/L² (55 mg²/dL²) had 4.8-fold higher odds of a cardiovascular event (95% confidence interval 1.36 to 16.81) compared with patients with no measurements above these ranges. In adult patients with chronic hypoparathyroidism, a cardiovascular event was more likely in those with a higher proportion of albumin-corrected serum calcium measurements outside 2.00 to 2.25 mmol/L (8.0 to 9.0 mg/100 ml) or any serum phosphate and any calcium-phosphate product measurements above the normal population range.

Complications, Symptoms, Presurgical Predictors in Patients With Chronic Hypoparathyroidism: A Systematic Review

The complications and symptoms of hypoparathyroidism remain incompletely defined. Measuring serum parathyroid hormone (PTH) and calcium levels early after total thyroidectomy may predict the development of chronic hypoparathyroidism. The study aimed (i) to identify symptoms and complications associated with chronic hypoparathyroidism and determine the prevalence of those symptoms and complications (Part I), and (ii) to examine the utility of early postoperative measurements of PTH and calcium in predicting chronic hypoparathyroidism (Part II). We searched Medline, Medline In-Process, EMBASE, and Cochrane CENTRAL to identify complications and symptoms associated with chronic hypoparathyroidism. We used two predefined criteria (at least three studies reported the complication and symptom and had statistically significantly greater pooled relative estimates). To estimate prevalence, we used the median and interquartile range (IQR) of the studies reporting complications and symptoms. For testing the predictive values of early postoperative measurements of PTH and calcium, we used a bivariate model to perform diagnostic test meta-analysis. In Part I, the 93 eligible studies enrolled a total of 18,973 patients and reported on 170 complications and symptoms. We identified nine most common complications or symptoms probably associated with chronic hypoparathyroidism. The complications or symptoms and the prevalence are as follows: nephrocalcinosis/nephrolithiasis (median prevalence among all studies 15%), renal insufficiency (12%), cataract (17%), seizures (11%), arrhythmia (7%), ischemic heart disease (7%), depression (9%), infection (11%), and all-cause mortality (6%). In Part II, 18 studies with 4325 patients proved eligible. For PTH measurement, regarding the posttest probability, PTH values above 10 pg/mL 12-24 hours postsurgery virtually exclude chronic hypoparathyroidism irrespective of pretest probability (100%). When PTH values are below 10 pg/mL, posttest probabilities range from 3% to 64%. Nine complications and symptoms are probably associated with chronic hypoparathyroidism. A PTH value above a threshold of 10 pg/mL 12-24 hours after total thyroidectomy is a strong predictor that the patients will not develop chronic hypoparathyroidism. Patients with PTH values below the threshold need careful monitoring as some will develop chronic hypoparathyroidism. © 2022 American Society for Bone and Mineral Research (ASBMR).

Etiology and Pathophysiology of Hypoparathyroidism: A Narrative Review

The approach utilized a systematic review of the medical literature executed with specifically designed criteria that focused on the etiologies and pathogenesis of hypoparathyroidism. Enhanced attention by endocrine surgeons to new knowledge about parathyroid gland viability are reviewed along with the role of intraoperative parathyroid hormone (ioPTH) monitoring during and after neck surgery. Nonsurgical etiologies account for a significant proportion of cases of hypoparathyroidism (~25%), and among them, genetic etiologies are key. Given the pervasive nature of PTH deficiency across multiple organ systems, a detailed review of the skeletal, renal, neuromuscular, and ocular complications is provided. The burden of illness on affected patients and their caregivers contributes to reduced quality of life and social costs for this chronic endocrinopathy. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Epidemiology and Financial Burden of Adult Chronic Hypoparathyroidism

Chronic hypoparathyroidism is characterized by low serum calcium, increased serum phosphorus, and inappropriately low or decreased serum parathyroid hormone. This rare disorder is associated with a variety of complications. The prevalence, incidence, mortality, financial burden, and epidemiology of complications of this disorder are not well understood. This narrative review summarizes current information on the epidemiology and complications of chronic hypoparathyroidism. The reported prevalence of chronic hypoparathyroidism ranges from 6.4-37/100,000, and the incidence is reported to be 0.8-2.3/100,000/year. Mortality is not increased in studies from Denmark or South Korea but was increased in studies from Scotland and Sweden. The financial burden of this disorder is substantial because of increased health care resource utilization in two studies but not well quantitated. Recognized complications include hypercalciuria, nephrocalcinosis, kidney stones, and chronic kidney disease; low bone turnover and possibly upper extremity fractures; cardiac and vascular calcifications; basal ganglia calcifications, cataracts, infections, neuropsychiatric complications, and difficulties with pregnancy. This review concludes that chronic hypoparathyroidism is a rare disorder associated with significant morbidity that may not increase overall mortality but is associated with a substantial financial burden. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Evaluation and Management of Hypoparathyroidism Summary Statement and Guidelines from the Second International Workshop

This clinical practice guideline addresses the prevention, diagnosis, and management of hypoparathyroidism (HypoPT) and provides evidence-based recommendations. The HypoPT task forces included four teams with a total of 50 international experts including representatives from the sponsoring societies. A methodologist (GG) and his team supported the taskforces and conducted the systematic reviews. A formal process following the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology and the systematic reviews provided the structure for seven of the guideline recommendations. The task force used a less structured approach based on narrative reviews for 20 non-GRADEd recommendations. Clinicians may consider postsurgical HypoPT permanent if it persists for >12 months after surgery. To predict which patients will not develop permanent postsurgical HypoPT, we recommend evaluating serum PTH within 12 to 24 hours post total thyroidectomy (strong recommendation, moderate quality evidence). PTH > 10 pg/mL (1.05 pmol/L) virtually excludes long-term HypoPT. In individuals with nonsurgical HypoPT, genetic testing may be helpful in the presence of a positive family history of nonsurgical HypoPT, in the presence of syndromic features, or in individuals younger than 40 years. HypoPT can be associated with complications, including nephrocalcinosis, nephrolithiasis, renal insufficiency, cataracts, seizures, cardiac arrhythmias, ischemic heart disease, depression, and an increased risk of infection. Minimizing complications of HypoPT requires careful evaluation and close monitoring of laboratory indices. In patients with chronic HypoPT, the panel suggests conventional therapy with calcium and active vitamin D metabolites as first-line therapy (weak recommendation, low-quality evidence). When conventional therapy is deemed unsatisfactory, the panel considers the use of PTH. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Quality of Life in Post-Surgical Hypoparathyroidism (PoSH) in Thyroid and Parathyroid Surgery

BACKGROUND

Post-surgical hypoparathyroidism (PoSH) is often long term, with significant associated morbidity and ongoing treatment. A recent systematic review found impaired quality of life (QoL) in patients with PoSH, despite stable treatment. Most studies did not include an appropriate control arm and further studies were recommended, taking into account underlying disease and comorbidities. This study aims to compare QoL in patients with PoSH with appropriate control groups.

METHODS

This was a cross-sectional observational study using the general quality of life SF-36 tool and a hypocalcaemia symptom score (HcSS) to assess QoL in patients with PoSH and controls (who had similar surgery but without PoSH). Participants were identified from two patient groups (the Butterfly Thyroid Cancer Trust and the Association for Multiple Endocrine Neoplasia Disorders) and a single tertiary centre in the UK.

RESULTS

Four hundred and thirty-nine responses (female n = 379, PoSH n = 89) were included with a median (range) age of 52 (19-92) years. Reported dates of surgery ranged from 1973 to 2019. HcSS scores showed significantly more associated symptoms in patients with PoSH than those without (p < 0.001). Although there was no overall difference in QoL between groups, patients with PoSH consistently had lower scores (p = 0.008) in the energy/fatigue subdomain of the SF-36.

CONCLUSION

Patients with PoSH reported significantly more fatigue and loss of energy compared to appropriately matched controls, but overall QoL was not significantly different. Standardised QoL measures may not be sensitive enough to highlight the impact on QoL in these patients. A disease-specific tool may be required.

Skeletal and nonskeletal consequences of hypoparathyroidism

Hypoparathyroidism, despite the conventional therapy with calcium and active vitamin D, can lead to skeletal and nonskeletal abnormalities. Chronic hypoparathyroidism is associated with a significant reduction in bone remodeling, increases in areal and volumetric bone density, and improvement in trabecular microarchitecture and in trabecular bone score. Regardless of these advantages in bone mass and microarchitecture, recent data suggest an increased vertebral fracture risk in patients with nonsurgical hypoparathyroidism. Moreover, chronic hypoparathyroidism can lead to abnormalities in multiple organ systems, including the neurological, cardiovascular, renal, neuropsychiatric, ocular, and immune systems. Nephrocalcinosis, nephrolithiasis, and renal insufficiency, as well as decreased quality of life and cataracts, are common in patients with hypoparathyroidism. An increased incidence of hospitalization due to infections and a greater risk of cardiovascular diseases are observed in patients with hypoparathyroidism, particularly in those with nonsurgical disease. All these abnormalities may be because of the disease itself or complications of therapy. We herein reviewed the skeletal and nonskeletal consequences of hypoparathyroidism in patients conventionally managed with calcium and active vitamin D.

Kidney Complications and Hospitalization in Patients With Chronic Hypoparathyroidism: A Cohort Study in Sweden

CONTEXT

Kidney complications may be considerably higher in patients with chronic hypoparathyroidism (hypoPT) treated with activated vitamin D and calcium supplementation.

OBJECTIVE

We aimed to investigate the risk of chronic kidney disease (CKD), urolithiasis, and hospitalization in patients with chronic hypoPT.

METHODS

In this population-based cohort study in Sweden, national registries (Swedish National Patient Register, Swedish Prescribed Drug Register, and Total Population Register, 1997-2018) were used to identify patients with chronic hypoPT and controls matched by sex, age, and county of residence. We determined time to CKD and urolithiasis diagnosis, and incidence rates of hospitalization.

RESULTS

A total of 1562 patients with chronic hypoPT without preexisting CKD and 15 620 controls were included. The risk of developing CKD was higher in patients with chronic hypoPT compared with controls (hazard ratio [HR] 4.45; 95% CI, 3.66-5.41). In people without prior urolithiasis (n = 1810 chronic hypoPT and n = 18 100 controls), the risk of developing urolithiasis was higher in patients with chronic hypoPT (HR 3.55; 95% CI, 2.84-4.44) compared with controls. Patients with chronic hypoPT had higher incidence rates for all-cause hospitalization (49.59; 95% CI, 48.50-50.70, per 100 person-years vs 28.43; 95% CI, 28.15-28.71, respectively) and for CKD (3.46; 95% CI, 3.18-3.76, per 100 person-years vs 0.72; 95% CI, 0.68-0.77, respectively), compared with controls. Men with hypoPT appear to have a higher risk of CKD than women.

CONCLUSION

Patients with chronic hypoPT had an increased risk of CKD, urolithiasis, and hospitalization compared with controls.

Effects of Multi-stage Procurement on the Viability and Function of Human Donor Parathyroid Glands

INTRODUCTION

Parathyroid allotransplantation is an emerging treatment for severe hypoparathyroidism. Ensuring the viability and functional integrity of donor parathyroid glands following procurement is essential for optimal transplantation outcomes.

METHODS

Cellular viability, calcium-responsive hormone secretion, and gland xenograft survival were assessed in a series of deceased donor parathyroid glands following a two-stage procurement procedure recently developed by our group (en bloc cadaveric dissection with subsequent gland isolation after transport to the laboratory).

RESULTS

Parathyroid glands resected in this manner and stored up to 48 h in 4°C University of Wisconsin (UW) media retained in vitro viability with no induction of hypoxic stress (HIF-1α) or apoptotic (caspase-3) markers. Ex vivo storage did not significantly affect parathyroid gland calcium sensing capacity, with comparable calcium EC50 values and suppression of parathyroid hormone secretion at high ambient calcium concentrations. The isolated glands engrafted readily, vascularizing rapidly in vivo following transplantation into mice.

CONCLUSIONS

Parathyroid tissue retains viability, calcium-sensing capacity, and in vivo engraftment capability after en bloc cadaveric resection, ex vivo dissection, and extended cold storage.

Safety and Efficacy of PTH 1-34 and 1-84 Therapy in Chronic Hypoparathyroidism: A Meta-Analysis of Prospective Trials

Hypoparathyroidism is the only endocrine deficiency for which hormone replacement therapy is not the standard of care. Although conventional treatments may control hypocalcaemia, other complications such as hyperphosphatemia, kidney stones, peripheral calcifications, and bone disease remain unmet needs. This meta-analysis (PROSPERO registration number CRD42019126881) aims to evaluate and compare the efficacy and safety of PTH_1-34 and PTH_1-84 in restoring calcium metabolism in chronic hypoparathyroidism. EMBASE, PubMed, and CENTRAL databases were searched for randomized clinical trials or prospective studies published between January 1996 and March 2021. English-language trials reporting data on replacement with PTH_1-34 or PTH_1-84 in chronic hypoparathyroidism were selected. Three authors extracted outcomes, one author performed quality control, all assessed the risk of biases. Overall, data from 25 studies on 588 patients were analyzed. PTH therapy had a neutral effect on calcium levels, while lowering serum phosphate (-0.21 mmol/L; 95% confidence interval [CI], -0.31 to -0.11 mmol/L; p < 0.001) and urinary calcium excretion (-1.21 mmol/24 h; 95% CI, -2.03 to -0.41 mmol/24 h; p = 0.003). Calcium phosphate product decreased under PTH_1-84 therapy only. Both treatments enabled a significant reduction in calcium and calcitriol supplementation. PTH therapy increased bone turnover markers and lumbar spine mineral density. Quality of life improved and there was no difference in the safety profile between PTH and conventionally treated patients. Results for most outcomes were similar for the two treatments. Limitations of the study included considerable population overlap between the reports, incomplete data, and heterogeneity in the protocol design. In conclusion, the meta-analysis of data from the largest collection to date of hypoparathyroid patients shows that PTH therapy is safe, well-tolerated, and effective in normalizing serum phosphate and urinary calcium excretion, as well as enabling a reduction in calcium and vitamin D use and improving quality of life. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Lower Risk of Cardiovascular Events in Adult Patients with Chronic Hypoparathyroidism Treated with rhPTH(1-84): A Retrospective Cohort Study

Introduction

Patients with chronic hypoparathyroidism are at increased risk of cardiovascular disease. This study evaluated the risk of developing cardiovascular conditions over a period of 5 years in adult patients with chronic hypoparathyroidism treated with recombinant human parathyroid hormone (1–84), rhPTH(1–84), compared with a historical control cohort of patients not treated with rhPTH(1–84).

Methods

This retrospective cohort study comprised patients with chronic hypoparathyroidism treated with rhPTH(1–84) in the REPLACE (NCT00732615), RELAY (NCT01268098), and RACE (NCT01297309) clinical trials, and controls selected from the IBM^® Explorys electronic medical record database (January 2007–August 2019) who did not receive parathyroid hormone but who had enrollment criteria similar to those for the clinical trials. Cardiovascular outcomes were the first diagnosis of cerebrovascular, coronary artery, peripheral vascular disease, or heart failure during the study period.

Results

We evaluated 113 adult patients with chronic hypoparathyroidism treated with rhPTH(1–84) and 618 control patients who did not receive rhPTH(1–84). Over the 5-year follow-up period, 3.5% of patients (n = 4) in the rhPTH(1–84) cohort had a cardiovascular event compared with 16.3% (n = 101) in the control cohort. Kaplan–Meier analysis demonstrated that patients in the rhPTH(1–84) cohort had lower risk of experiencing a cardiovascular event compared with patients in the control cohort (P = 0.005). Multivariable analyses adjusted for baseline variables showed that patients in the rhPTH(1–84) cohort had 75% lower risk for a cardiovascular event compared with patients in the control cohort (adjusted hazard ratio, 0.25 [95% CI 0.08–0.81]; P = 0.020).

Conclusion

Long-term treatment with rhPTH(1–84) was associated with a lower risk of incident cardiovascular conditions compared with conventional therapy in patients with chronic hypoparathyroidism. Previous studies demonstrated that mineral homeostasis was maintained with lower use of calcium and active vitamin D when rhPTH(1–84) was added to conventional therapy. Future studies are needed to understand whether improved regulation of mineral homeostasis conferred by rhPTH(1–84) may provide long-term cardiovascular benefits to patients with chronic hypoparathyroidism.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-022-02198-y.

Supplemental calcium and vitamin D and long-term mortality in aortic stenosis

Objective

Calcium metabolism has long been implicated in aortic stenosis (AS). Studies assessing the long-term safety of oral calcium and/or vitamin D in AS are scarce yet imperative given the rising use among an elderly population prone to deficiency. We sought to identify the associations between supplemental calcium and vitamin D with mortality and progression of AS.

Methods

In this retrospective longitudinal study, patients aged ≥60 years with mild-moderate native AS were selected from the Cleveland Clinic Echocardiography Database from 2008 to 2016 and followed until 2018. Groups were stratified into no supplementation, supplementation with vitamin D alone and supplementation with calcium±vitamin D. The primary outcomes were mortality (all-cause, cardiovascular (CV) and non-CV) and aortic valve replacement (AVR), and the secondary outcome was AS progression by aortic valve area and peak/mean gradients.

Results

Of 2657 patients (mean age 74 years, 42% women) followed over a median duration of 69 months, 1292 (49%) did not supplement, 332 (12%) took vitamin D alone and 1033 (39%) supplemented with calcium±vitamin D. Calcium±vitamin D supplementation was associated with a significantly higher risk of all-cause mortality (absolute rate (AR)=43.0/1000 person-years; HR=1.31, 95% CI (1.07 to 1.62); p=0.009), CV mortality (AR=13.7/1000 person-years; HR=2.0, 95% CI (1.31 to 3.07); p=0.001) and AVR (AR=88.2/1000 person-years; HR=1.48, 95% CI (1.24 to 1.78); p<0.001). Any supplementation was not associated with longitudinal change in AS parameters in a linear mixed-effects model.

Conclusions

Supplemental calcium with or without vitamin D is associated with lower survival and greater AVR in elderly patients with mild-moderate AS.

Unrecognized Primary Hypoparathyroidism with Severe Hypocalcemia in the Presence of COVID-19 Infection

Primary hypoparathyroidism (PHPT) is a rare disease most commonly caused by surgical parathyroid glands destruction or genetic disorders. PHPT manifestation varies from subclinical to acute or even lethal symptoms. In atypical presentation the signs of hypocalcemia could be missed, and asymptotic chronic hypocalcemia could manifest only in the presence of exacerbated comorbidities, infections, hypomagnesemia or certain medications. We present a case of PHPT with severe hypocalcemia manifesting as seizures and delirium in a presence of COVID-19 infection.

Identifying Clinical Characteristics of Hypoparathyroidism in Turkey: HIPOPARATURK-NET Study

Hypoparathyroidism is an orphan disease with ill-defined epidemiology that is subject to geographic variability. We conducted this study to assess the demographics, etiologic distribution, treatment patterns and complication frequency of patients with chronic hypoparathyroidism in Turkey. This is a retrospective, cross-sectional database study, with collaboration of 30 endocrinology centers located in 20 cities across seven geographical regions of Turkey. A total of 830 adults (mean age 49.6 ± 13.5 years; female 81.2%) with hypoparathyroidism (mean duration 9.7 ± 9.0 years) were included in the final analysis. Hypoparathyroidism was predominantly surgery-induced (n = 686, 82.6%). The insulting surgeries was carried out mostly due to benign causes in postsurgical group (SG) (n = 504, 73.5%) while patients in nonsurgical group (NSG) was most frequently classified as idiopathic (n = 103, 71.5%). The treatment was highly dependent on calcium salts (n = 771, 92.9%), calcitriol (n = 786, 94.7%) and to a lower extent cholecalciferol use (n = 635, 76.5%) while the rate of parathyroid hormone (n = 2, 0.2%) use was low. Serum calcium levels were most frequently kept in the normal range (sCa 8.5-10.5 mg/dL, n = 383, 46.1%) which might be higher than desired for this patient group. NSG had a lower mean plasma PTH concentration (6.42 ± 5.53 vs. 9.09 ± 7.08 ng/l, p < 0.0001), higher daily intake of elementary calcium (2038 ± 1214 vs. 1846 ± 1355 mg/day, p = 0.0193) and calcitriol (0.78 ± 0.39 vs. 0.69 ± 0.38 mcg/day, p = 0.0057), a higher rate of chronic renal disease (9.7% vs. 3.6%, p = 0.0017), epilepsy (6.3% vs. 1.6%, p = 0.0009), intracranial calcifications (11.8% vs. 7.3%, p < 0.0001) and cataracts (22.2% vs. 13.7%, p = 0.0096) compared to SG. In conclusion, postsurgical hypoparathyroidism is the dominant etiology of hypoparathyroidism in Turkey while the nonsurgical patients have a higher disease burden with greater need for medications and increased risk of complications than the postsurgical patients.

Association of Calcium and Phosphate Levels with Incident Chronic Kidney Disease in Patients with Hypoparathyroidism: A Retrospective Case-Control Study

OBJECTIVE

Reasons for the increased incidence of chronic kidney disease (CKD) in patients with chronic hypoparathyroidism are poorly understood. This study evaluated associations between levels of albumin-corrected serum calcium, serum phosphate, and calcium-phosphate product and the odds of CKD development in patients with chronic hypoparathyroidism.

DESIGN

A retrospective nested case-control study of adult patients with chronic hypoparathyroidism who had ≥1 prescription for calcitriol who developed CKD and matched controls who did not develop CKD were selected from the IBM® Explorys electronic medical record database. Patients. The study included a cohort of 300 patients for the albumin-corrected serum calcium analysis and 80 patients for the serum phosphate and calcium-phosphate product analyses. Measurements. We examined associations between albumin-corrected serum calcium, serum phosphate and calcium-phosphate product levels, and the risk of devloping CKD (defined as ≥2 outpatient estimated glomerular filtration values <60 mL/min/1.73 m² occuring ≥3 months apart or ≥1 diagnostic code for CKD stages 3-5).

RESULTS

Individuals who had ≥67% of albumin-corrected serum calcium measurements outside, above, or below the study-defined range (2.00-2.25 mmol/L [8.0-9.0 mg/dL]) had 3.5-, 2.9-, and 2.7-fold higher odds of developing CKD (adjusted odds ratios [95% CI]: 3.46 [1.82-6.56], 2.85 [1.30-6.28], and 2.68 [1.16-6.15]), respectively, compared with patients who had <33% of albumin-corrected calcium measurements in those ranges. There was no association between developing CKD and having any serum phosphate measurements or any calcium-phosphate product measurements above normal population ranges.

CONCLUSION

In adult patients with chronic hypoparathyroidism, a higher proportion of albumin-corrected calcium measurements outside of the 2.00-2.25 mmol/L (8.0-9.0 mg/dL) range was associated with higher odds of developing CKD.

Five-Year Estimated Glomerular Filtration Rate in Adults with Chronic Hypoparathyroidism Treated with rhPTH(1-84): A Retrospective Cohort Study

INTRODUCTION

Chronic hypoparathyroidism is associated with higher risk of developing chronic kidney disease compared with the general population. This study evaluated changes in estimated glomerular filtration rate (eGFR) over a 5-year period in adult patients with chronic hypoparathyroidism treated with recombinant parathyroid hormone (1-84), rhPTH(1-84), compared with a historical control cohort of patients who did not receive rhPTH(1-84).

METHODS

This retrospective cohort study included patients with chronic hypoparathyroidism treated with rhPTH(1-84) in the REPLACE (NCT00732615), RELAY (NCT01268098), RACE (NCT01297309), and HEXT (NCT01199614 and continuation study NCT02910466) clinical trials. A historical control cohort who did not receive parathyroid hormone but who had enrollment criteria similar to those for the clinical trials was selected from the IBM® Explorys electronic medical record database (January 2007-August 2019). Outcomes of interest were the annual rate of change in eGFR from baseline (i.e., eGFR slope) and the predicted eGFR change from baseline at years 1 through 5.

RESULTS

The study comprised 72 adult patients with chronic hypoparathyroidism treated with rhPTH(1-84) and 176 control patients who did not receive rhPTH(1-84). Over 5 years, eGFR remained stable in the rhPTH(1-84) cohort, whereas eGFR declined at a rate of 1.67 mL/min/1.73 m² per year in the control cohort (P < 0.001 for eGFR slope in the control cohort). At 5 years, predicted eGFR in the rhPTH(1-84) cohort increased from baseline by 1.21 mL/min/1.73 m², whereas eGFR in the control cohort declined by 10.36 mL/min/1.73 m², after adjusting for baseline variables. The difference in eGFR slopes between the cohorts over 5 years was 1.37 mL/min/1.73 m² per year (95% CI 0.62-2.13; P < 0.001).

CONCLUSION

Long-term treatment with rhPTH(1-84) was associated with stable eGFR compared with eGFR decline in the controls not treated with rhPTH(1-84). Preservation of renal function conferred by rhPTH(1-84) may benefit patients with chronic hypoparathyroidism by reducing risk of long-term renal complications.

Effect of postsurgical chronic hypoparathyroidism on morbidity and mortality: a systematic review and meta-analysis

Background

Hypoparathyroidism (HypoPT) is a common sequela of anterior neck surgeries. While the acute risks of HypoPT are well known, emerging evidence is beginning to define the risks chronic HypoPT poses to patients. This meta-analysis aims to evaluate that risk and give more insight into its consequences.

Methods

A systematic review and meta-analysis were performed, searching EMBASE, Web of Science, and Scopus for studies published up to July 1, 2020 and reported following PRISMA guidelines. Pooled analysis was estimated using the Mantel-Haenszel method and a random-effects model. A sub-analysis of the pooled data for each morbidity was performed and demonstrated in forest plots.

Results

Patients with postsurgical chronic HypoPT had a high risk of cardiac morbidities [odds ratio (OR) =1.43; 95% confidence interval (95% CI): 1.21 to 1.70; P<0.001] in the absence of elevated risk of cardiac arrhythmias (OR =1.35, 95% CI: 0.96 to 1.79, P=0.08). Analysis also showed higher odds of developing renal disease (OR =4.85, 95% CI: 3.54 to 6.67, P<0.001), renal stones (OR =3.86, 95% CI: 1.81 to 8.23, P<0.001), seizures (OR =2.41, 95% CI: 1.66 to 3.5, P<0.001), mental health problems (OR =1.46, 95% CI: 1.21 to 1.77, P<0.001), and infections (OR =1.51, 95% CI: 1.28 to 1.78, P<0.001). Conversely, HypoPT has no effect on mortality risk (OR =1.19, 95% CI: 0.96 to 1.49, P=0.12).

Conclusions

Postsurgical HypoPT patients are vulnerable to a variety of medical and psychiatric diseases. This meta-analysis should guide surgeons in preoperative counseling and postoperative care for patients undergoing anterior neck surgeries.

The PARADIGHM (physicians advancing disease knowledge in hypoparathyroidism) registry for patients with chronic hypoparathyroidism: study protocol and interim baseline patient characteristics

BACKGROUND

The PARADIGHM registry of adult and pediatric patients with chronic hypoparathyroidism evaluates the long-term safety and effectiveness of treatment with recombinant human parathyroid hormone, rhPTH(1-84), and describes the clinical disease course under conditions of routine clinical practice. In this first report, we detail the registry protocol and describe the baseline characteristics of two adult patient cohorts from an interim database analysis. One cohort after study entry were prescribed rhPTH(1-84), and the other cohort received conventional therapy of calcium and active vitamin D.

METHODS

An observational study of patients with chronic hypoparathyroidism in North America and Europe, collecting data for ≥10 years per patient. Main outcome measures were baseline patient demographics, clinical characteristics, medications, and disease outcome variables of symptoms, biochemical parameters, and health assessments. Baseline is the enrollment assessment for all variables except biochemical measurements in patients treated with rhPTH(1-84); those measurements were the most recent value before the first rhPTH(1-84) dose. Exclusion criteria applied to the analysis of specified outcomes included pediatric patients, patients who initiated rhPTH(1-84) prior to enrollment, and those who received rhPTH(1-34). Clinically implausible biochemical outlier data were excluded.

RESULTS

As of 30 June 2019, data of 737 patients were analyzed from 64 centers; 587 (80%) were women, mean ± SD age 49.1±16.45 years. At enrollment, symptoms reported for patients later prescribed rhPTH(1-84) (n=60) and those who received conventional therapy (n=571), respectively, included fatigue (51.7%, 40.1%), paresthesia (51.7%, 29.6%), muscle twitching (48.3%, 21.9%), and muscle cramping (41.7%, 33.8%). Mean serum total calcium, serum phosphate, creatinine, and estimated glomerular filtration rate were similar between cohorts. Health-related quality of life (HRQoL) 36-item Short Form Health Survey questionnaire scores for those later prescribed rhPTH(1-84) were generally lower than those for patients in the conventional therapy cohort.

CONCLUSIONS

At enrollment, based on symptoms and HRQoL, a greater percentage of patients subsequently prescribed rhPTH(1-84) appeared to have an increased burden of disease than those who received conventional therapy despite having normal biochemistry measurements. PARADIGHM will provide valuable real-world insights on the clinical course of hypoparathyroidism in patients treated with rhPTH(1-84) or conventional therapy in routine clinical practice.

TRIAL REGISTRATION

EUPAS16927, NCT01922440.

Fracture risk in hypoparathyroidism: a systematic review and meta-analysis

In this meta-analysis, we analyzed 7 observational studies for assessing the fracture risk in patients with hypoparathyroidism (hypoPT). We found that the risk of vertebral fractures is increased by almost 2-fold, especially those with nonsurgical hypoPT.

PURPOSE

Patients with hypoPT have higher bone mineral density than age- and sex-matched controls. This would theoretically translate into a lower risk of fractures, although available clinical evidence is contradictory. Hence, the present systematic review and meta-analysis was undertaken to collate and provide a precise summary of fracture risk in hypoPT.

METHODS

PubMed, Scopus, and Web of Science databases were systematically searched using appropriate keywords till March 8, 2021, to identify observational studies reporting the rate of occurrence of fractures among hypoPT patients (nonsurgical and/or postsurgical) compared to non-hypoPT subjects (controls). Study quality was assessed using Newcastle-Ottawa Scale. Pooled odds ratio (OR) with 95% confidence intervals (CI) was calculated. Subgroup analyses of nonsurgical and postsurgical hypoPT patients were also conducted.

RESULTS

We identified 7 observational studies of high-quality pooling data retrieved from 1470 patients with hypoPT. When stratified based on the skeletal site, pooled analyses showed that hypoPT patients were at an increased risk of vertebral fractures compared to non-hypoPT controls (OR 2.22, 95% CI: 1.23, 4.03, p = 0.009, I² = 49%, random-effects model). The increased risk of vertebral fractures was seen only in patients with nonsurgical hypoPT (OR 2.31, 95% CI: 1.32, 4.03, p = 0.003, I² = 3%, random-effects model) but not in those with postsurgical hypoPT. hypoPT patients were not at an increased or decreased risk of any, humerus, or proximal femur/hip fractures than controls.

CONCLUSIONS

Nonsurgical hypoPT patients are at an almost 2-fold increased risk of vertebral fractures and thus need to be actively screened irrespective of the underlying BMD.

Risk of Cardiovascular Conditions in Patients with Chronic Hypoparathyroidism: A Retrospective Cohort Study

Introduction

In patients with chronic hypoparathyroidism disordered calcium homeostasis has been associated with risk of cardiovascular diseases, including cardiomyopathy, congestive heart failure, and arrhythmia; however, larger-scale studies are needed to examine these risks. This study evaluated the risk of cardiovascular conditions among patients with chronic hypoparathyroidism.

Methods

Adults with and without chronic hypoparathyroidism were selected from a medical insurance claims database in the USA from January 2007 to June 2017, and were followed for up to 5 years. Associations between chronic hypoparathyroidism and incident atrial fibrillation (AF), tachyarrhythmia, myocardial infarction (MI), coronary artery disease (CAD), heart failure (HF), stroke, cerebrovascular disease, peripheral vascular disease (PVD), and a combined cardiovascular endpoint of cerebrovascular disease, CAD, HF, and PVD were compared between cohorts using Kaplan–Meier analyses and unadjusted and adjusted Cox proportional hazards models.

Results

In 8097 patients with chronic hypoparathyroidism compared with 40,485 patients without, respectively, mean ± SD ages were 58.6 ± 16.3 and 47.3 ± 18.0 years, 76.2% and 54.4% were female, and 19.4% and 9.5% had the combination of cardiovascular findings at baseline. In adjusted analyses, patients with chronic hypoparathyroidism had significantly higher risk (adjusted hazard ratio and 95% confidence interval) of incident AF (1.72; 1.51–1.97), tachyarrhythmia (1.68; 1.32–2.14), MI (1.18; 1.01–1.38), CAD (1.39; 1.26–1.54), HF (1.64; 1.46–1.84), stroke (1.45; 1.31–1.62), cerebrovascular disease (1.48; 1.34–1.62), PVD (1.66; 1.51–1.81), and combined cardiovascular endpoint (1.63; 1.52–1.75), all P < 0.001 except P = 0.036 for MI, compared with patients without chronic hypoparathyroidism.

Conclusions

This large retrospective cohort study showed that chronic hypoparathyroidism was associated with increased risk of incident cardiovascular conditions and arrhythmias. Results should be evaluated in light of limitations inherent to claims database analyses. Further studies are warranted to investigate reasons for these risks and to develop strategies for reducing cardiovascular conditions in patients with chronic hypoparathyroidism.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-01787-7.

Parathyroid allotransplantation for the treatment of permanent hypoparathyroidism: A systematic review

BACKGROUND

Hypoparathyroidism is the most common complication of bilateral operations in the central neck. No formal guidelines exist for the management of permanent hypoparathyroidism. Current treatment involving medical supplementation increases resource utilization and patient morbidity while decreasing quality of life. Parathyroid allotransplant (PA) offers a promising therapy; however, the optimal technique and role of immunosuppression (IS) in PA remain unclear.

METHODS

We performed a systematic search of the Embase, MEDLINE, and Cochrane Library databases to identify studies investigating PA for treatment of hypoparathyroidism.

RESULTS

A total of 24 studies including 186 individual allograft transplants in 146 patients were identified. Pooled graft survival for allotransplants in transplant-naïve vs prior transplant recipients was 29.9% and 80%, respectively.

CONCLUSIONS

PA using normocellular, fresh parathyroid donor tissue that is ABO-compatible, with induction and, at minimum, short-term maintenance IS presents a potentially safe and effective therapeutic option for permanent hypoparathyroidism in patients tolerating IS.

Lower Leg Arterial Calcifications Assessed by High-Resolution Peripheral Quantitative Computed Tomography in Hypoparathyroid and Pseudohypoparathyroid Patients

Hypoparathyroidism (HypoPT) and pseudohypoparathyroidism (PHP) are diseases with abnormal calcium and phosphate homeostasis and low and high PTH levels, respectively. It has been hypothesized that this could dispose to vascular calcifications and thereby perhaps also cardiovascular morbidity. The aim of this study was to assess lower leg arterial calcifications (LLAC) in patients with HypoPT or PHP. Using a cross-sectional design, we measured the LLAC using a high-resolution peripheral quantitative computed tomography (HR-pQCT) scanner in 72 patients with HypoPT and 25 patients with PHP and compared them with findings in 61 controls. LLAC were found in only two (3%) of the controls. Compared to the controls, LLAC were significantly more prevalent in patients with HypoPT (N = 12, [17%], p < 0.01) and PHP (N = 4, [16%], p < 0.04). Compared to the patients without calcifications, patients with calcifications had higher plasma calcium levels and a lower eGFR, as well as they were older and more often males. Plasma phosphate levels and the calcium-phosphate product were not associated with LLAC. In conclusion, we found that HypoPT and PHP are associated with an increased prevalence of vascular calcifications.

Canadian national hypoparathyroidism registry: an overview of hypoparathyroidism in Canada

PURPOSE

To evaluate the epidemiology, presentation and management of hypoparathyroidism in Canada. Hypoparathyroidism is associated with significant morbidity and poor quality of life. We present baseline results from the Canadian National Hypoparathyroidism Registry, a prospective observational study evaluating hypoparathyroidism in Canada.

METHODS

Our study enrolled 130 patients with hypoparathyroidism. Patients were followed every 6 months with clinical and lab assessments. We present baseline data in this manuscript.

RESULTS

Seventy percent (91/130) of patients had postsurgical hypoparathyroidism, 30% (39/130) of patients had nonsurgical hypoparathyroidism due to autoimmune, genetic or idiopathic causes, and a molecular diagnosis was confirmed in 11 of these 39 patients. Pseudohypoparathyroidism was confirmed in 4/39 patients, DiGeorge syndrome in 2/39 patients, Barakat syndrome with a mutation in the GATA3 gene in 1/39, and activating mutations of the CASR gene in 3/39 patients with nonsurgical hypoparathyroidism. Renal complications with nephrocalcinosis or nephrolithiasis were present in 27% (14/52) of patients with postsurgical disease and 17% (4/24) of patients with nonsurgical hypoparathyroidism. Basal ganglia calcification was noted on imaging in 15% (n = 5/34) of patients with postsurgical hypoparathyroidism and 37% (n = 7/19) of patients with nonsurgical hypoparathyroidism.

CONCLUSIONS

Hypercalciuria was more commonly seen in those with renal complications of nephrocalcinosis, nephrolithiasis or CKD, and hyperphosphatemia was more commonly seen in those with basal ganglia calcification. Hospitalization occurred in 28% of those with postsurgical hypoparathyroidism and 46% of those with nonsurgical hypoparathyroidism. Hypoparathyroidism is associated with significant morbidity. Effective strategies to reduce the short-and long-term complications of hypoparathyroidism need to be developed and evaluated.

Impaired Immune Function in Patients With Chronic Postsurgical Hypoparathyroidism: Results of the EMPATHY Study

CONTEXT

Despite the pivotal role of calcium signaling in immune response, little is known about immune function in patients affected by hypoparathyroidism.

OBJECTIVE

This work aimed to evaluate immune function in hypoparathyroidism.

METHODS

The Evaluation of iMmune function in Postsurgical and AuToimmune HYpoparathyroidism (NCT04059380) is a case-control, cross-sectional study set in an Italian referral center. Participants included 20 patients with postsurgical hypoparathyroidism (12 females) and 20 age- and sex-matched controls. Main outcome measures included calcium metabolism assessment, peripheral blood mononuclear cells (PBMC) profiling via flow cytometry, parathyroid hormone receptor 1 (PTHr1) expression analysis using immunofluorescence and PrimeFlow RNA assay, gene expression analysis via real-time polymerase chain reaction, cytokine measurement, and evaluation of infectious disease frequency and severity.

RESULTS

Immune cell profiling revealed decreased monocytes, regulatory, naive, and total CD4+ T lymphocytes, which correlated with total calcium, ionized calcium, and PTH levels, in patients with hypoparathyroidism. Patients with hypoparathyroidism had a higher CD3-CD56+ natural killer (NK) cell count, which inversely correlated with calcium, PTH, and vitamin D levels. Furthermore, they exhibited decreased tumor necrosis factor (TNF) and granulocyte-macrophage colony-stimulating factor gene expression and decreased circulating TNF levels. Gene expression and immunofluorescence analysis confirmed PTHr1 expression in all PBMC lineages; however, the percentage of cells expressing PTHr1 was lower, whereas the intensity of PTHr1 expression in monocytes, total T lymphocytes, CD8+CD4+ and CD4+ T lymphocytes, and total NK cells was higher in patients with hypoparathyroidism.

CONCLUSIONS

This study describes for the first time the immune alterations in patients with hypoparathyroidism receiving conventional therapies, supporting the immunoregulatory role of PTH and proposing an explanation for the increased susceptibility to infections observed in epidemiological studies.

Risk of Chronic Kidney Disease and Estimated Glomerular Filtration Rate Decline in Patients with Chronic Hypoparathyroidism: A Retrospective Cohort Study

INTRODUCTION

Chronic hypoparathyroidism, treated with conventional therapy of oral calcium supplements and active vitamin D, may increase the risk of kidney complications. This study examined risks of development and progression of chronic kidney disease (CKD) and estimated glomerular filtration rate (eGFR) decline in patients with chronic hypoparathyroidism.

METHODS

A retrospective cohort study using a managed care claims database in the United States from January 2007 to June 2017 included patients with chronic hypoparathyroidism (excluding those receiving parathyroid hormone) and randomly selected patients without hypoparathyroidism followed for up to 5 years. Main outcome measures were (1) development of CKD, defined as new diagnosis of CKD stage 3 and higher or ≥ 2 eGFR measurements < 60 ml/min/1.73 m² ≥ 3 months apart, (2) progression of CKD, defined as increase in baseline CKD stage, (3) progression to end-stage kidney disease (ESKD), and (4) eGFR decline ≥ 30% from baseline. Time-to-event analyses included Kaplan-Meier analyses with log-rank tests, and both unadjusted and adjusted Cox proportional hazards models were used to compare outcomes between cohorts.

RESULTS

The study included 8097 adults with and 40,485 without chronic hypoparathyroidism. In Kaplan-Meier analyses, patients with chronic hypoparathyroidism had higher risk of developing CKD and CKD progression and higher rates of eGFR decline (all P < 0.001). In multivariable Cox models adjusted for baseline characteristics, hazard ratios (95% confidence intervals [CIs]) were 2.91 (2.61-3.25) for developing CKD, 1.58 (1.23-2.01) for CKD stage progression, 2.14 (1.51-3.04) for progression to ESKD, and 2.56 (1.62-4.03) for eGFR decline (all P < 0.001) among patients with chronic hypoparathyroidism compared with those without hypoparathyroidism.

CONCLUSION

Patients with chronic hypoparathyroidism have increased risk of development and progression of CKD and eGFR decline compared with those without hypoparathyroidism. Further studies are warranted to understand underlying mechanisms for the associations between chronic hypoparathyroidism and kidney disease.

Beyond Bone: Infectious Diseases and Immunity in Parathyroid Disorders

Parathyroid disorders are characterized by alterations in calcium and phosphate homeostasis due to inappropriately high or low levels of parathyroid hormone (PTH). Despite PTH receptor type 1 has been described in almost all immune lineages and calcium signalling has been confirmed as a crucial mediator for immune response, in vitro studies on the physiological interactions between PTH and immunity are conflicting and not representative of the clinical scenarios seen in patients with parathyroid disorders. Infectious diseases are among the main causes of increased morbidity and mortality in patients with secondary hyperparathyroidism and chronic kidney disease. More, immune alterations have been described in primary hyperparathyroidism. Recent studies have unveiled an increased risk of infections also in hypoparathyroidism, suggesting that not only calcium, but also physiological levels of PTH may be necessary for a proper immune response. Finally, calcium/phosphate imbalance could affect negatively the prognosis of infectious diseases. Our review aimed to collect available data on infectious disease prevalence in patients with parathyroid disorders and new evidence on the role of PTH and calcium in determining the increased risk of infections observed in these patients.

Controversy: For or against thyroid lobectomy in>1cm differentiated thyroid cancer?

In this controversy article, the respective advantages of lobectomy vs. total thyroidectomy in differentiated thyroid cancers are argued. The authors conclude that lobectomy has the same oncological prognosis as thyroidectomy in terms of specific survival or recurrence, in case of low risk of recurrence (T1-2N0). However, as a precaution, and taking into account current data, thyroidectomy is recommended in N0 thyroid papillary cancers with aggressive subtype, with even minimal infiltration of perithyroid tissue and/or vascular invasion, and in N1 cancers with more than 5 lymphadenopathies or lymphadenopathies with a major axis greater than or equal to 0.2cm. Other forms of papillary cancer should be treated with lobectomy, as risk of morbidity is low and hospital stay is short. Lobectomy allows reliable monitoring, especially by ultrasound. On the other hand, total thyroidectomy, despite a higher rate of surgical complications due to the risk of recurrent paralysis and permanent hypoparathyroidism, is nevertheless preferable to lobectomy. Indeed lobectomy is not always avoiding hormone replacement therapy, for more precise monitoring by thyroglobulin assay, which is an uninterpretable tool after lobectomy but allows early diagnosis of local or metastatic recurrence with reducing mortality. Thus, in situations where the diagnostic criteria for high-risk cancer are not rigorously determined or taken into account, thyroidectomy is recommended. In addition, it will remain preferable as long as the recommendations for administration of radioactive iodine do not change in favor of use reserved for high-risk cancers as in US guidelines.

Permanent postoperative hypoparathyroidism: an analysis of prevalence and predictive factors for adequacy of control in a cohort of 260 patients

Background

Recent guidelines for the treatment of hypoparathyroidism emphasize the need for long-term disease control, avoiding symptoms and hypocalcaemia. Our aim has been to analyze the prevalence of poor disease control in a national cohort of patients with hypoparathyroidism, as well as to evaluate predictive variables of inadequate disease control.

Methods

From a nation-wide observational study including a cohort of 1792 patients undergoing total thyroidectomy, we selected 260 subjects [207 women and 53 men, aged (mean ± SD) 47.2±14.8 years] diagnosed with permanent hypoparathyroidism. In every patient demographic data and details on surgical procedure, histopathology, calcium (Ca) metabolism, and therapy with Ca and calcitriol were retrospectively collected. A patient was considered not adequately controlled (NAC) if presented symptoms of hypocalcemia or biochemical data showing low serum Ca levels or high urinary Ca excretion.

Results

Two hundred and twenty-one (85.0%) patients were adequately controlled (AC) and 39 (15.0%) were NAC. Comparison between AC and NAC patients did not show any significant difference in demographic, surgical, and pathological features. Rate of hospitalization during follow-up was significantly higher among NAC patients in comparison with AC patients (35.9% vs. 10.9%, P<0.001). Dose of oral Ca and calcitriol were also significantly higher in NAC subjects. In a subgroup of 129 patients with serum parathyroid hormone (PTH) levels available, we found that NAC patients exhibited significantly lower postoperative PTH concentrations than AC patients [median (interquartile range) 3 (1.9-7.8) vs. 6.9 (3.0-11) pg/mL; P=0.009].

Conclusions

In a nation-wide cohort of 260 subjects with definitive hypoparathyroidism, 15% of them had poor disease control. These patients required higher doses of oral Ca and calcitriol, had higher rate of hospitalization during follow-up and showed lower PTH concentrations in the postoperative period.

Thyroid Lobectomy for Low to Intermediate Risk Differentiated Thyroid Cancer

Simple Summary

Total thyroidectomy used to be recommended for all thyroid cancers. We now know that some thyroid cancers have a relatively low risk of recurrence. Today, for some of these cancers, depending on the type of tumor, its’ size and other tumor characteristics, a thyroid lobectomy (or hemithyroidectomy) can be performed without increasing the patient’s risk of cancer recurrence. Thyroid lobectomy has the advantages of having less risk of surgical complications and a less frequent need for thyroid hormone replacement therapy. This approach is not optimal for all thyroid cancers, however, and careful tumor and patient selection are necessary. This review explains the rationale and criteria for patient selection for thyroid lobectomy for selected thyroid cancers.

Abstract

Many recent publications and guidelines have promoted a “more is less” approach in terms of treatment for low to intermediate risk differentiated thyroid cancer (DTC), which comprise the vast majority of thyroid cancers: less extensive surgery, less radioactive iodine, less or no thyroid hormone suppression, and less frequent or stringent follow-up. Following this approach, thyroid lobectomy has been proposed as a means of decreasing short- and long-term postoperative morbidity while maintaining an excellent prognosis for tumors meeting specific macroscopic and microscopic criteria. This article will examine the pros and cons of thyroid lobectomy for low to intermediate risk cancers and discuss, in detail, criteria for patient selection and oncological outcomes.