Increased vertebral morphometric fracture in patients with postsurgical hypoparathyroidism despite normal bone mineral density

Serum autotaxin is a prognostic indicator of liver-related events in patients with non-alcoholic fatty liver disease

BACKGROUND

Circulating autotaxin (ATX) levels have been reported to correlate with liver inflammation activity and liver fibrosis severity in patients with non-alcoholic fatty liver disease (NAFLD). The objective of this study is to investigate whether serum ATX could predict liver-related events (LRE) in NAFLD patients.

METHODS

This retrospective investigation includes 309 biopsy-proven NAFLD patients registered at Shinshu University Hospital. All patients are followed for at least 1 year, during which time the prevalence of LRE, including newly developing hepatocellular carcinoma, hepatic encephalopathy, ascites, and esophagogastric varices, is investigated in relation to ATX levels at the time of liver biopsy.

RESULTS

During the median follow-up period of 7.0 years, LRE are observed in 20 patients (6.5%). The area under the receiver operating characteristic curve and cut-off value of serum ATX for predicting LRE are 0.81 and 1.227 mg/l, respectively. Multivariate Cox proportional hazards models for LRE determine ATX and advanced fibrosis as independently associated factors. Furthermore, in a competing risk analysis that considered non-liver-related death as a competing event, ATX (HR 2.29, 95% CI 1.22-4.30, p = 0.010) is identified as an independent factor associated with LRE, along with advanced fibrosis (HR 8.01, 95% CI 2.10-30.60, p = 0.002). The predictive utility of ATX for LRE is validated in an independent cohort.

CONCLUSIONS

Serum ATX may serve as a predictive marker for LRE in patients with NAFLD.

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.

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.

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).

Fasting indices of glucose-insulin-metabolism across life span and prediction of glycemic deterioration in children with obesity from new diagnostic cut-offs

Background

Fasting indices of glucose-insulin-metabolism are an easy and affordable tool to assess insulin resistance. We aimed to establish reference ranges for fasting insulin indices that reflect age-dependent variation over the entire life span and subsequently test their clinical application regarding the prediction of glycemic deterioration in children.

Methods

We calculated age- and puberty-dependent reference values for HOMA-IR, HOMA2-IR, HOMA-β, McAuley index, fasting insulin, and fasting glucose from 6994 observations of 5512 non-obese healthy subjects aged 5-80 years. Applying those references, we determined the prevalence of insulin resistance among 2538 subjects with obesity. Furthermore, we investigated the intraindividual stability and the predictive values for future dysglycemia of these fasting indices in 516 children and adolescents with obesity up to 19 years of follow-up. We validated the results in three independent cohorts.

Findings

There was a strong age-dependent variation of all indices throughout the life span, including prolonged recovery of pubertal insulin resistance and a subsequent continuous increase throughout adulthood. Already from age 5 years onwards, >40% of children with obesity presented with elevated parameters of insulin resistance. Applying newly developed reference ranges, insulin resistance among children with obesity doubled the risk for future glycemic deterioration (HOMA-IR HR 1.88 (95% CI 1.1-3.21)), fasting insulin HR 1.89 (95% CI 1.11-3.23). In contrast, fasting glucose alone was not predictive for emerging dysglycemia in children with obesity (HR 1.03 (95% CI 0.62-1.71)). The new insulin-based thresholds were superior to fasting glucose and HbA1c in detecting children eventually manifesting with dysglycemia in prospective analyses.

Interpretation

The variation of fasting glucose-insulin-metabolism across the life span necessitates age-specific reference ranges. The improved prediction of future glycemic deterioration by indices based on fasting insulin beyond simple glucose measures alone could help to stratify risk characteristics of children with obesity in order to guide patient-tailored prevention and intervention approaches.

Funding

German Research Foundation (DFG)-through SFB 1052, project number 209933838, subproject C5; Federal Ministry of Education and Research, Germany; European Union-European Regional Development Fund; Free State of Saxony. The German Diabetes Association, the CarbHealth consortium (01EA1908B). EU-IMI2-Consortium SOPHIA (grant agreement No 875534), German Center for Diabetes Research (DZD), grant number 82DZD14E03.

Vitamin D in hypoparathyroidism: insight into pathophysiology and perspectives in clinical practice

Hypoparathyroidism (HypoPT) is a rare endocrine disorder characterized by the absence or insufficient parathyroid hormone production resulting in chronic hypocalcemia. Complications of HypoPT include perturbation of several target organs. The conventional treatment consists of the administration of active vitamin D, namely calcitriol. Regarding vitamin D status, few data are available, mostly in HypoPT subjects supplemented with parent vitamin D. In addition, perturbation of vitamin D metabolism has been poorly investigated, as well as the contribution of altered vitamin D status on the clinical expression of the disease. The most recent consensus on the management of chronic HypoPT suggests the baseline evaluation of serum 25-hydroxy-vitamin D [25(OH)D] and supplementation with parent vitamin D with the aim to achieve and maintain serum 25(OH)D levels in the range of 30-50 ng/mL. The rationale for using supplementation with parent vitamin D (either ergocalciferol or cholecalciferol) in HypoPT would be to provide sufficient 25(OH)D substrate to the residual 1-α-hydroxylase activity, thus ensuring its conversion to active vitamin D in renal and extra-renal tissues. More data from experimental and clinical studies are needed for better assessing how these mechanisms may significantly influence metabolic control in HypoPT and eventually skeletal and extra-skeletal manifestation of the disease. Finally, future data will clarify how the currently available parent vitamin D compounds (ergocalciferol, cholecalciferol, calcifediol) would perform in addressing these specific issues.

Prevalence and factors associated with drug therapy problems among hypertensive patients at hypertension clinic of Mbarara Regional Referral Hospital, Uganda: a |cross-sectional study

BACKGROUND

Despite the use of safe and effective conventional drugs, drug therapy problems (DTPs) pose a threat to the successful management of hypertension. DTPs are of a great concern in health care because of their serious consequences such as poor quality of life, increased health care costs, morbidity and mortality. However, there is no published information regarding the prevalence of DTPs and associated factors among hypertensive patients in Uganda.

OBJECTIVE

The aim of the study was to determine the prevalence and factors associated with DTPs among hypertensive patients at the hypertension clinic of Mbarara Regional Referral Hospital (MRRH).

METHOD

A cross-sectional study was conducted at the hypertension clinic, MRRH, Uganda among 228 hypertensive patients. Data were collected from medical records using a data abstraction tool and patients were interviewed using a structured questionnaire. Data analysis was done using Statistical Package for Social Sciences (SPSS) version 22.0. Descriptive analysis was used to determine the prevalence of DTPs. Logistic regression was used to determine the association between the independent and dependent variables. Variables were considered statistically significant at p-value <0.05.

RESULTS

A total of 178 DTPs were identified among 141 hypertensive patients. The prevalence of antihypertensive-related DTPs was 61.8% (95% confidence interval [CI]: 55.3-67.5) with an average of 1.26 ± 0.52 DTPs per patient. Out of 141 participants with DTPs, 109 (77.3%) had one DTP, 27 (19.1%) had 2 DTPs, and 5 (3.5%) had 3 DTPs. The most common types of antihypertensive-related DTPs were 'dosage too low' which accounted for 53 (29.8%), followed by 'adverse drug reactions' which accounted for 48 (27%). Uncontrolled blood pressure (BP; adjusted odds ratio [AOR]: 4.17; 95% CI: 2.33-7.45, p < 0.001) and routine laboratory test results (AOR: 1.87; 95% CI: 1.04-3.36, p = 0.036) were significantly associated with antihypertensive-related DTPs among hypertensive patients.

CONCLUSION

Almost two-thirds of study participants had antihypertensive-related DTPs. The most common DTPs were 'dosage too low' and 'adverse drug reactions' which both accounted for almost a third of the total DTPs each. Uncontrolled BP and routine laboratory test results were significantly associated with antihypertensive-related DTPs among the study participants. Our study emphasizes the need for improved patient care by clinical pharmacists to identify and prevent DTPs among hypertensive patients.

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).

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).

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.

Vertebral fractures, trabecular bone score and their determinants in chronic hypoparathyroidism

PURPOSE

Patients with hypoparathyroidism are at risk of vertebral fractures (VFs) despite high bone mineral density (BMD). We investigated this paradox by assessing trabecular bone score (TBS) and hip structural analysis (HSA) in non-surgical chronic hypoparathyroidism (cHypoPT) with and without VFs.

METHODS

152 cHypoPT patients (age 40.2 ± 13.4 years, M: F = 81:71) with a median follow-up of 8 (2-13) years were assessed for BMD, VFs, TBS, and HSA and compared with 152 healthy controls. VFs at T₇-L₄ were assessed by Genant's method. Average serum total calcium and phosphorus during follow-up were assessed.

RESULTS

The lumbar spine and hip BMD were higher by 25.4 and 13.4% in cHypoPT than controls (P < 0.001). Paradoxically, VFs (30.9 vs.7.9%), including multiple (12.5 vs. 2.6%) were higher in cHypoPT (P < 0.001). Though overall average TBS (1.411 ± 0.091) was normal in cHypoPT, 25.4% of the females had subnormal TBS, more in post than pre-menopausal women (52.3 vs. 14%, P = 0.002) and as compared to males (6.1%, P = 0.001). TBS correlated with menopausal status and follow-up serum calcium-phosphorus product. For every gm/cm² rise in BMD, TBS increase was only 0.227 in cHypoPT compared to 0.513 in controls. Frequency of VFs increased with declining TBS (P = 0.004). HSA was comparable between cHypoPT with and without VFs. 23.4% of cHypoPT with VFs had subnormal TBS.

CONCLUSION

31% of cHypoPT patients had VFs. TBS indicated degraded bone microarchitecture in 50% of the post-menopausal cHypoPT women. However, TBS has limitations to detect abnormal bone microarchitecture in cHypoPT as only one-fourth of patients with VFs showed low TBS.

Secondary Osteoporosis and Metabolic Bone Diseases

Fragility fracture is a worldwide problem and a main cause of disability and impaired quality of life. It is primarily caused by osteoporosis, characterized by impaired bone quantity and or quality. Proper diagnosis of osteoporosis is essential for prevention of fragility fractures. Osteoporosis can be primary in postmenopausal women because of estrogen deficiency. Secondary forms of osteoporosis are not uncommon in both men and women. Most systemic illnesses and organ dysfunction can lead to osteoporosis. The kidney plays a crucial role in maintaining physiological bone homeostasis by controlling minerals, electrolytes, acid-base, vitamin D and parathyroid function. Chronic kidney disease with its uremic milieu disturbs this balance, leading to renal osteodystrophy. Diabetes mellitus represents the most common secondary cause of osteoporosis. Thyroid and parathyroid disorders can dysregulate the osteoblast/osteoclast functions. Gastrointestinal disorders, malnutrition and malabsorption can result in mineral and vitamin D deficiencies and bone loss. Patients with chronic liver disease have a higher risk of fracture due to hepatic osteodystrophy. Proinflammatory cytokines in infectious, autoimmune, and hematological disorders can stimulate osteoclastogenesis, leading to osteoporosis. Moreover, drug-induced osteoporosis is not uncommon. In this review, we focus on causes, pathogenesis, and management of secondary osteoporosis.

Morphometric vertebral fracture risk in women with postsurgical hypoparathyroidism

INTRODUCTION

Hypoparathyroidism (HP) is a rare endocrine disease and there are little data available on the risk of fragility fractures in these patients. PTH deficiency results in a positive bone balance with higher bone mass in all skeletal sites. However, whether these structural and dynamic skeletal changes have a negative impact on the fracture risk, it is not known.

METHODS

Aiming to investigate the risk of insufficiency vertebral fractures in HP, defined using morphometric criteria, a consecutive sampling of 44 women with chronic postsurgical HP was compared to a control group of 44 adult healthy women, matched by age with patients. Vertebral fractures were analyzed by the semiquantitative Genant's method followed by quantitative vertebral morphometry.

RESULTS

Morphometric vertebral fractures were identified in 5/44 (11.4%) patients and in 3/44 (6.8%) controls (p=0.731). Most fractures were classified as Genant II and III grades in HP patients, whereas most were Genant I in controls. A logistic regression multivariate analysis was conducted in which age, BMI and parathyroid status were the independent variables, and morphometric vertebral fracture was the dependent variable, but none of these factors was a significant predictor of fracture in this population (OR 1.01, 95% CI 0.96-1.07, p=0.634 for age; OR 2.24, 95%CI 0.47-10.50, p=0.306 for the presence/absence of HP and OR 0.92, 95% CI 0.76-1.10, p=0.369 for BMI).

CONCLUSION

The results of this study cannot ensure a higher risk of fragility vertebral fractures in postsurgical HP patients. Instead, we only observed higher Genant grade classification of the deformed vertebrae in our sample.

Skeletal abnormalities in Hypoparathyroidism and in Primary Hyperparathyroidism

Both hypoparathyroidism (HypoPT), as well as its pathological counterpart, primary hyperparathyroidism (PHPT), can lead to skeletal abnormalities. Chronic deficiency of PTH in patients with HypoPT is associated with a profound reduction in bone remodeling, with consequent increases in bone density, and abnormalities in microarchitecture and bone strength. It is still not clear whether there is an increase in fracture risk in HypoPT. While standard therapy with calcium supplements and active vitamin D does not restore bone homeostasis, treatment of HypoPT with PTH appears to correct some of those abnormalities. In PHPT, the continuous exposure to high levels of PTH causes an increase in bone remodeling, in which bone resorption prevails. In the symptomatic form of PHPT, patients can present with fragility fractures, and/or the classical radiological features of osteitis fibrosa cystica. However, even in mild PHPT, catabolic skeletal actions of PTH are evident through reduced BMD, deterioration of bone microarchitecture and increased risk of fragility fractures. Successful parathyroidectomy improves skeletal abnormalities. Medical treatment, such as bisphosphonates and denosumab, can also increase bone density in patients with PHPT who do not undergo surgery. This article reviews skeletal involvement in HypoPT and in PHPT, as assessed by bone remodeling, DXA, trabecular bone score, and quantitative computed tomography, as well as data on bone strength and fracture risk. The effects of PTH replacement on the skeleton in subjects with HypoPT, and the outcome of parathyroidectomy in patients with PHPT, are also reviewed here.

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.

Effects of 4-Hexylresorcinol on Craniofacial Growth in Rats

4-Hexylresorcinol (4HR) has been used as a food additive, however, it has been recently demonstrated as a Class I histone deacetylase inhibitor (HDACi). Unlike other HDACi, 4HR can be taken through foods. Unfortunately, some HDACi have an influence on craniofacial growth, therefore, the purpose of this study was to evaluate the effects of 4HR on craniofacial growth. Saos-2 cells (osteoblast-like cells) were used for the evaluation of HDACi and its associated activities after 4HR administration. For the evaluation of craniofacial growth, 12.8 mg/kg of 4HR was administered weekly to 4 week old rats (male: 10, female: 10) for 12 weeks. Ten rats were used for untreated control (males: 5, females: 5). Body weight was recorded every week. Serum and head samples were collected at 12 weeks after initial administration. Craniofacial growth was evaluated by micro-computerized tomography. Serum was used for ELISA (testosterone and estrogen) and immunoprecipitation high-performance liquid chromatography (IP-HPLC). The administration of 4HR (1-100 μM) showed significant HDACi activity (p < 0.05). Body weight was significantly different in male rats (p < 0.05), and mandibular size was significantly smaller in 4HR-treated male rats with reduced testosterone levels. However, the mandibular size was significantly higher in 4HR treated female rats with increased growth hormone levels. In conclusion, 4HR had HDACi activity in Saos-2 cells. The administration of 4HR on growing rats showed different responses in body weight and mandibular size between sexes.

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.

Vertebral Fracture Assessment in Postmenopausal Women With Postsurgical Hypoparathyroidism

CONTEXT

Hypoparathyroidism is a rare endocrine disorder whose skeletal features include suppression of bone turnover and greater volume and width of the trabecular compartment. Few and inconsistent data are available on the prevalence of vertebral fractures (VF).

OBJECTIVE

To evaluate the prevalence of VF assessed by vertebral fracture assessment (VFA) in postmenopausal women with chronic postsurgical hypoparathyroidism.

DESIGN

Cross-sectional study.

SETTING

Ambulatory referral center.

PATIENTS OR OTHER PARTICIPANTS

Fifty postmenopausal women (mean age 65.4 ± 9 years) with chronic postsurgical hypoparathyroidism and 40 age-matched healthy postmenopausal women (mean age 64.2 ± 8.6).

MAIN OUTCOME MEASURES

Lumbar spine, femoral neck, and total hip bone mineral density were measured by dual X-ray absorptiometry (Hologic Inc., USA) in all subjects. Site-matched spine trabecular bone score was calculated by TBS iNsight (Medimaps, Switzerland). Assessment of VF was made by VFA (iDXA, Lunar GE, USA) using the semiquantitative method and the algorithm-based qualitative assessment.

RESULTS

All-site BMD values were higher in the hypoparathyroid vs the control group. By VFA, we observed a 16% prevalence of VF in hypoparathyroid women vs 7.5% in control subjects. Among those with hypoparathyroidism who fractured, 5 (62.5%) had grade 1 wedge, 2 (25%) had grade 2 wedge, and 1 (12.5%) had grade 2 wedge and grade 2 biconcave VF. In the hypoparathyroid group, 57% with VFs and 32% without VFs had symptoms of hypoparathyroidism.

CONCLUSION

We demonstrate for the first time that in postmenopausal women with chronic postsurgical hypoparathyroidism, VFs are demonstrable by VFA despite normal BMD.

Hipopara-Red, Real Life Experience in 322 Patients With Hypoparathyroidism

Context

Hypoparathyroidism is a rare disease and, as such, its natural history, long-term complications, and correct clinical management remain unclear.

Objective

To describe the natural history and clinical characteristics of the disease.

Design and Setting

To present a retrospective observational analysis from 7 specialized centers in Buenos Aires, Argentina.

Patients

Chronic hypoparathyroid patients followed-up between 1985 and December 2018.

Main Outcome Measures

Data on demographics, etiology, clinical complications, biochemical parameters, dual-energy x-ray absorptiometry (DXA) values, and treatment doses were collected.

Results

A total of 322 subjects with chronic hypoparathyroidism were included; 85.7% were female, the mean age was 55.2 ± 16.8 years, and the mean age at diagnosis was 43.8 ± 16.8 years. Prevalence of surgical hypoparathyroidism was 90.7%, with the most common causes being thyroid carcinoma and benign thyroid disease. A history of hypocalcemia requiring hospitalization was present in 25.7% of the whole group and in 4.3% of patients who had a history of seizures. Overall, 40.9% of our patients had reported at least 1 neuromuscular symptom. Renal insufficiency was present in 22.4% of our patients and was significantly associated with age (P < 0.0001). Hyperphosphatemia was present in 42% of patients. A history of severe hypocalcemia, paresthesias, tetany, ganglia calcifications, seizures, and cataracts was significantly higher in nonsurgical patients.

Conclusion

Although these patients were followed-up by experienced physicians, clinical management was heterogeneous and probably insufficient to assess all the potential complications of this chronic disease. Almost 70% of the study’s group of patients met the experts’ indications for considering the use of rhPTH 1–84. Being aware of this fact is the 1^st step in improving our medical management of this disease in the future.

Management of parathyroid disorders: recommendations of the working group of the Bone Section of the Hellenic Endocrine Society

The Bone Section of the Hellenic Endocrine Society has issued the recommendations herein presented with the aim of providing guidance on optimal management of patients with parathyroid disorders in everyday clinical practice within the Greek health care setting. Although the methodology followed to formulate these recommendations was not strictly based on the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) principles, they were drawn up after an extensive review of the literature and of the currently available guidelines for the management of parathyroid disorders worldwide. Specifically for primary hyperparathyroidism (PHPT), the 2011 guidelines of the Greek National Organization of Medicines were updated accordingly. In particular, definitions, etiologies, and recommended and optional laboratory and imaging examinations are provided both for PHPT and chronic hypoparathyroidism (HypoPT). Finally, treatment algorithms are provided for the management of both PHPT and HypoPT. Specifically for HypoPT, the treatment algorithm describes the recommended steps that should be followed to achieve optimal management of chronic hypocalcemia and the complications of HypoPT through the conventional treatment available in Greece and the use of recombinant human PTH(1-84).

Parathyroid hormone

Parathyroid hormone is an essential regulator of extracellular calcium and phosphate. PTH enhances calcium reabsorption while inhibiting phosphate reabsorption in the kidneys, increases the synthesis of 1,25-dihydroxyvitamin D, which then increases gastrointestinal absorption of calcium, and increases bone resorption to increase calcium and phosphate. Parathyroid disease can be an isolated endocrine disorder or part of a complex syndrome. Genetic mutations can account for diseases of parathyroid gland formulation, dysregulation of parathyroid hormone synthesis or secretion, and destruction of the parathyroid glands. Over the years, a number of different options are available for the treatment of different types of parathyroid disease. Therapeutic options include surgical removal of hypersecreting parathyroid tissue, administration of parathyroid hormone, vitamin D, activated vitamin D, calcium, phosphate binders, calcium-sensing receptor, and vitamin D receptor activators to name a few. The accurate assessment of parathyroid hormone also provides essential biochemical information to properly diagnose parathyroid disease. Currently available immunoassays may overestimate or underestimate bioactive parathyroid hormone because of interferences from truncated parathyroid hormone fragments, phosphorylation of parathyroid hormone, and oxidation of amino acids of parathyroid hormone.

Changes in Skeletal Microstructure Through Four Continuous Years of rhPTH(1-84) Therapy in Hypoparathyroidism

Bone remodeling is reduced in hypoparathyroidism, resulting in increased areal bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA) and abnormal skeletal indices by transiliac bone biopsy. We have now studied skeletal microstructure by high-resolution peripheral quantitative computed tomography (HR-pQCT) through 4 years of treatment with recombinant human PTH(1-84) (rhPTH[1-84]) in 33 patients with hypoparathyroidism (19 with postsurgical disease, 14 idiopathic). We calculated Z-scores for our cohort compared with previously published normative values. We report results at baseline and 1, 2, and 4 years of continuous therapy with rhPTH(1-84). The majority of patients (62%) took rhPTH(1-84) 100 μg every other day for the majority of the 4 years. At 48 months, areal bone density increased at the lumbar spine (+4.9% ± 0.9%) and femoral neck (+2.4% ± 0.9%), with declines at the total hip (-2.3% ± 0.8%) and ultradistal radius (-2.1% ± 0.7%) (p < .05 for all). By HR-pQCT, at the radius site, very similar to the ultradistal DXA site, total volumetric BMD declined from baseline but remained above normative values at 48 months (Z-score + 0.56). Cortical volumetric BMD was lower than normative controls at baseline at the radius and tibia (Z-scores -1.28 and - 1.69, respectively) and further declined at 48 months (-2.13 and - 2.56, respectively). Cortical porosity was higher than normative controls at baseline at the tibia (Z-score + 0.72) and increased through 48 months of therapy at both sites (Z-scores +1.80 and + 1.40, respectively). Failure load declined from baseline at both the radius and tibia, although remained higher than normative controls at 48 months (Z-scores +1.71 and + 1.17, respectively). This is the first report of noninvasive high-resolution imaging in a cohort of hypoparathyroid patients treated with any PTH therapy for this length of time. The results give insights into the effects of long-term rhPTH(1-84) in hypoparathyroidism. © 2020 American Society for Bone and Mineral Research.

Prevalence and complications of nonsurgical hypoparathyroidism in Korea: A nationwide cohort study

OBJECTIVE

The risk of complications of nonsurgical hypoparathyroidism in Asia is unclear. We estimated the prevalence and risk of complications in patients with nonsurgical hypoparathyroidism.

METHODS

We performed a retrospective cohort study using a nationwide claims database from 2005 to 2016. Among the entire Korean population, we identified 897 patients diagnosed with nonsurgical hypoparathyroidism during 2005-2015. We selected 210 patients with nonsurgical hypoparathyroidism during 2005-2008 who had no complications at baseline and followed them to 2016. Control subjects (n = 2075) were matched using propensity scores based on age, sex, and comorbid disease with a 1:10 ratio and monitored until 2016.

RESULTS

The age-standardized prevalence of nonsurgical hypoparathyroidism was 0.2 cases per 100,000 persons in 2005. During a mean follow-up period of 9.5 years, patients with nonsurgical hypoparathyroidism had a higher risk of cardiovascular disease, especially arrhythmia (hazard ratio [HR], 2.03; 95% confidence interval [CI], 1.11-3.70) and heart failure (HR, 2.43; 95% CI, 1.22-4.83). The risk of vertebral fracture was higher in patients than in controls (HR, 2.27; 95% CI, 1.09-4.72). Patients had a significantly increased risk of renal disease (HR, 2.57; 95% CI, 1.56-4.21), seizure (HR, 5.74; 95% CI, 3.34-9.86), depression and bipolar disease (HR, 1.82; 95% CI, 1.30-2.56), and cataract (HR, 1.90; 95% CI, 1.30-2.79) compared with controls.

CONCLUSIONS

The prevalence of nonsurgical hypoparathyroidism was very low in Korea but was associated with a higher risk of incident cardiovascular disease and vertebral fracture as well as known complications including renal disease, seizure, and cataract.

Update on hypoparathyroidism

PURPOSE OF REVIEW

Hypoparathyroidism is a rare endocrine disorder characterized by low or insufficient parathyroid hormone (PTH) concentrations leading to hypocalcemia, hyperphosphatemia, and markedly reduced bone turnover. Despite being a rare disease, hypoparathyroidism has a profound impact on affected patients.

RECENT FINDINGS

Recent epidemiologic surveys demonstrate a prevalence of between 5.3 and 40/100 000, confirming the orphan status of this disease. There is a female predominance, and anterior neck surgery is the most common etiology. Recent studies have better elucidated the chronic manifestations of the disease, impacting quality of life and multiple organ systems including the renal, cardiovascular, and skeletal systems. There are now data on longer term use of parathyroid hormone (PTH) and PTH analogs.

SUMMARY

This review focuses on recent contributions to the literature on the prevalence and epidemiology of the disease, risk of chronic manifestations, and treatment with PTH(1-34) and rhPTH(1-84). Further research is needed to determine the pathophysiology of complications in hypoparathyroidism and whether interventions can decrease future risk of these complications. In addition, further data are needed with regards to more physiologic dosing regimens and long-term treatment with PTH and PTH analogs.

Predictors of Poor Bone Microarchitecture Assessed by Trabecular Bone Score in Postsurgical Hypoparathyroidism

CONTEXT

The effects of PTH deprivation on bone are still unclear. Our objective was to report the characteristics of patients with postsurgical hypoparathyroidism (PsH) at a specialized outpatient service and correlate their trabecular bone score (TBS) values to clinical, densitometric, and laboratory findings. A secondary objective was to evaluate the fracture rates and look for associations between these events and the collected data.

RESULTS

Eighty-two patients were enrolled, of whom 70 (85.4%) were female and 17 (20.7%) had type 2 diabetes mellitus (T2DM). The median body mass index (BMI) was 27.7 kg/m2 and the median age was 59 years. Of 68 dual-energy x-ray absorptiometry (DXA) scans obtained, osteopenia and osteoporosis were present in 32.4% and 2.9%, respectively. In all, 62 lumbar scans were analyzed by using TBS. The mean TBS value (±SD) was 1.386 ± 0.140, and 32.2% of the results were <1.310. TBS values correlated negatively with BMI (mainly > 30 kg/m2), age (mainly > 60 years), and glycemia, whereas abnormal TBS correlated with osteopenia, T2DM, low-impact fracture, and menopause. Six female patients had low-impact fractures, which were associated with a lower TBS (1.178 ± 0.065 vs. 1.404 ± 0.130 in the group without fractures; P < 0.001), older age, higher BMI, impaired renal function, abnormal glycemia, and osteopenia.

CONCLUSION

The findings suggests that known risk factors for bone loss compromise the bone microarchitecture of individuals with PsH, regardless of DXA results. Menopausal women with PsH and older patients with PsH who have osteopenia, a higher BMI, or T2DM may be candidates for a more detailed assessment by using, for example, TBS.

Risk of vertebral fractures in hypoparathyroidism

Parathyroid hormone (PTH) exerts both anabolic and catabolic actions on bone,depending on the duration and periodicity of exposure. Hypoparathyroidism is defined by inadequate production of PTH in the presence oflow serum calcium. In hypoparathyroidism it has been reported an increase in corticaland trabecular bone mass, but it is still unknown if these quantitative variations maybe accompanied by qualitative ones and increased bone strength. Despite the extensive data available on the effects of hypoparathyroidism on bone, itseffect on the hard end point in this area which is the risk of fractures still remainsunresolved and highly debated. As a matter of fact no previous review has focused onthis relevant clinical topic. This review will deal with the various aspects of bone metabolism (turn-over,density, quality) in hypoparathyroidism, focusing on the few data available on therisk of fracture and in particular of morphometric vertebral fractures, the emerging way to assess actual skeletal fragility particularly in secondary forms of osteoporosis.

Hypoparathyroidism: is it that easy to treat?

Hypoparathyroidism is a relatively rare endocrine disease characterised by either null or inappropriately low secretion of parathyroid hormone (PTH) for serum calcium levels. The other main laboratory findings include hypocalcaemia, inappropriately normal or high urine calcium excretion and hyperphosphataemia with low urine phosphate excretion. The management of hypoparathyroidism should be tailored to each individual case, which makes it a demanding undertaking in everyday clinical practice. In this review, we sought to focus on the diagnostic approach of hypoparathyroidism and the therapeutic challenges of the disease from a clinical perspective. Conventional treatment with vitamin D analogues and calcium salts is no longer the only available treatment, since replacement treatment with PTH(1-84) has recently been approved for the disease. However, the optimal treatment schedule is yet to be defined.

Trabecular bone score and bone mineral density in patients with postsurgical hypoparathyroidism after total thyroidectomy for differentiated thyroid carcinoma

BACKGROUND

Although bone mineral density is reported to be increased in patients with postsurgical hypoparathyroidism (postsurgical HypoPT), the effect of HypoPT on trabecular bone score remains unknown. This study evaluated the long-term effects of HypoPT secondary to total thyroidectomy for differentiated thyroid cancer on trabecular bone score, bone mineral density, and bone turnover markers with a similar group of patients without HypoPT.

METHODS

Women with resected differentiated thyroid cancer and either postsurgical HypoPT (n = 25; 8 premenopausal and 17 postmenopausal) or euparathyroid function (n = 98; 14 premenopausal and 84 postmenopausal) were matched for age and body mass index. Patients received thyroid-stimulating hormone suppression during follow-up. The bone mineral density and trabecular bone score were analyzed using dual x-ray densitometry and Med-Imaps software at baseline (1-3 months postsurgery) and at the final study visit.

RESULTS

Follow-up duration was similar in studied groups (median 10 years). Baseline bone mineral density and trabecular bone score were similar between HypoPT and non-HypoPT patients, regardless of menopausal status. At study end, postmenopausal HypoPT patients had greater bone mineral density versus the non-HypoPT patients at the lumbar spine, hip, and distal radius (P = .001), and a greater trabecular bone score (1.31 ± 0.09 vs 1.24 ± 0.12, P = .0184). Premenopausal patients with and without HypoPT had similar bone mineral density values at the final evaluation. The bone turnover markers (osteocalcin, bone-specific alkaline phosphatase, and β-crosslaps) were less in postmenopausal HypoPT patients, reflecting decreased bone turnover.

CONCLUSION

Postmenopausal patients who underwent a total thyroidectomy for differentiated thyroid cancer with postsurgical HypoPT have greater trabecular bone score and bone mineral density compared with euparathyroid patients, suggesting that HypoPT protects against the negative effects of long-term thyroid-stimulating hormone suppression treatment on bone.

Diagnosis and treatment of hypoparathyroidism: a position statement from the Brazilian Society of Endocrinology and Metabolism

Objective To present an update on the diagnosis and treatment of hypoparathyroidism based on the most recent scientific evidence. Materials and methods The Department of Bone and Mineral Metabolism of the Sociedade Brasileira de Endocrinologia e Metabologia (SBEM; Brazilian Society of Endocrinology and Metabolism) was invited to prepare a document following the rules set by the Guidelines Program of the Associação Médica Brasileira (AMB; Brazilian Medical Association). Relevant papers were retrieved from the databases MEDLINE/PubMed, LILACS, and SciELO, and the evidence derived from each article was classified into recommendation levels according to scientific strength and study type. Conclusion An update on the recent scientific literature addressing hypoparathyroidism is presented to serve as a basis for the diagnosis and treatment of this condition in Brazil.

Repurposing a novel parathyroid hormone analogue to treat hypoparathyroidism

BACKGROUND AND PURPOSE

Human parathyroid hormone (PTH) is critical for maintaining physiological calcium homeostasis and plays an important role in the formation and maintenance of the bone. Full-length PTH and a truncated peptide form are approved for treatment of hypoparathyroidism and osteoporosis respectively. Our initial goal was to develop an improved PTH therapy for osteoporosis, but clinical development was halted. The novel compound was then repurposed as an improved therapy for hypoparathyroidism.

EXPERIMENTAL APPROACH

A longer-acting form of PTH was synthesised by altering the peptide to increase cell surface residence time of the bound ligand to its receptor. In vitro screening identified a compound, which was tested in an animal model of osteoporosis before entering human trials. This compound was subsequently tested in two independent animal models of hypoparathyroidism.

KEY RESULTS

The peptide identified, LY627-2K, exhibited delayed internalization kinetics. In an ovariectomy-induced bone loss rat model, LY627-2K demonstrated improved vertebral bone mineral density and biomechanical properties at skeletal sites and a modest increase in serum calcium. In a Phase I clinical study, dose-dependent increases in serum calcium were reproduced. These observations prompted us to explore a second indication, hypoparathyroidism. In animal models of this disease, LY627-2K restored serum calcium, comparing favourably to treatment with wild-type PTH.

CONCLUSIONS AND IMPLICATIONS

We summarize the repositioning of a therapeutic candidate with substantial preclinical and clinical data. Our results support its repurposing and continued development, from a common indication (osteoporosis) to a rare disease (hypoparathyroidism) by exploiting a shared molecular target.

LINKED ARTICLES

This article is part of a themed section on Inventing New Therapies Without Reinventing the Wheel: The Power of Drug Repurposing. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.2/issuetoc.

[Recombinant human parathyroid hormone in the therapy of hypoparathyroidism]

Hypoparathyroidism is an endocrine disease that results from deficiency or complete absence of parathyroid hormone (PTH), a biologically active 84-amino acid polypeptide. Standard therapy for chronic hypoparathyroidism includes oral calcium salts and active vitamin D metabolites and is aimed at maintaining a balance between optimal near-normal serum calcium concentration and normocalcuria. Traditional treatment regimens not always lead to the compensation for calcium and phosphorus metabolism. Until recently, hypoparathyroidism is the only endocrine disorder that has not been treated with the recombinant hormone. To date, two recombinant PTH forms have been synthesized, which can be used as pathogenetic therapy for hypoparathyroidism. This review is dedicated to replacement therapy for hypoparathyroidism, by using both the full-length PTH molecule (1-84) and its shorter, but fully active, PTH form (1-34). This review considers stages in the developmental of hormone replacement therapy for hypoparathyroidism, discusses the most rational dosing regimens, and compares their efficacy and safety, as well as prospects for the development of this area.

[Not Available]

Parathormone (PTH), produced by parathyroid glands, is the main regulator of calcium homeostasis. Hypoparathyroidism (hypoPT), due to decrease of PTH production, is a rare disease. Symptoms are multiple, altering function of several organs and leading to a decrease of quality of life. Acquired etiologies, including thyroïdectomy, the main cause of hypoPT, can be distinguished from congenital etiologies, including genetic defects. HypoPT, which is classically treated by supplementation by calcium and active vitamin D, can now be treated by recombinant injection in certain indications as a poor control under classical therapy. Here are summarized current knowledge on etiologies, epidemiology, clinical manifestations and management of hypoPT.

Site-Specific Difference of Bone Geometry Indices in Hypoparathyroid Patients

BACKGROUND

Hypoparathyroid patients often have a higher bone mineral density (BMD) than the general population. However, an increase in BMD does not necessarily correlate with a solid bone microstructure. This study aimed to evaluate the bone microstructure of hypoparathyroid patients by using hip structure analysis (HSA).

METHODS

Ninety-five hypoparathyroid patients >20 years old were enrolled and 31 of them had eligible data for analyzing bone geometry parameters using HSA. And among the control data, we extracted sex-, age-, and body mass index-matched three control subjects to each patient. The BMD data were reviewed retrospectively and the bone geometry parameters of the patients were analyzed by HSA.

RESULTS

The mean Z-scores of hypoparathyroid patients at the lumbar spine, femoral neck, and total hip were above zero (0.63±1.17, 0.48±1.13, and 0.62±1.10, respectively). The differences in bone geometric parameters were site specific. At the femoral neck and intertrochanter, the cross-sectional area (CSA) and cortical thickness (C.th) were higher, whereas the buckling ratio (BR) was lower than in controls. However, those trends were opposite at the femoral shaft; that is, the CSA and C.th were low and the BR was high.

CONCLUSION

Our study shows the site-specific effects of hypoparathyroidism on the bone. Differences in bone components, marrow composition, or modeling based bone formation may explain these findings. However, further studies are warranted to investigate the mechanism, and its relation to fracture risk.

Skeletal changes after restoration of the euparathyroid state in patients with hypoparathyroidism and primary hyperparathyroidism

Restoration of the euparathyroid state is associated with improvement of bone dynamics both in hypoparathyroidism and primary hyperparathyroidism. To date, no study has directly compared these two groups following correction of parathyroid hormone excess or deficiency. The study was designed to investigate changes in bone mineral density and trabecular bone score with restoration of the euparathyroid state by parathyroidectomy in primary hyperparathyroidism or recombinant parathyroid hormone [rhPTH(1-84)] replacement in hypoparathyroidism. This was a 2-year prospective intervention study in which we evaluated areal bone mineral density by DXA and trabecular bone score in 52 hypoparathyroid patients on rhPTH(1-84) replacement and 27 patients with primary hyperparathyroidism who underwent parathyroidectomy. We evaluated changes in areal bone mineral density by DXA and trabecular bone score at baseline, 6, 12, 18, and 24 months. After parathyroidectomy, areal bone mineral density increased from baseline at the lumbar spine and total hip at 6 months and at the femoral neck at 12 months, while there were no changes at the distal 1/3 radius. Treatment with rhPTH(1-84) was associated with significant increases in lumbar spine and decreases in distal 1/3 radius areal bone mineral density by 18 months in hypoparathyroid patients. At this time point, hypoparathyroid subjects demonstrated a significant increase in trabecular bone score from baseline, while there were no significant changes in trabecular bone score following parathyroidectomy. Bone mineral density increases both with administration of parathyroid hormone in a state of parathyroid hormone deficiency or removal of parathyroid hormone in a state of parathyroid hormone excess. However, only hypoparathyroid patients on rhPTH(1-84) appeared to have improvements in micro-architectural pattern as assessed by trabecular bone score.

Bone imaging in hypoparathyroidism

Hypoparathyroidism (HypoPT) is an uncommon endocrine disorder characterized by chronic deficiency or absence of parathyroid hormone (PTH), which leads to a profound reduction in bone remodeling. Subjects with HypoPT typically have bone mineral densities (BMDs) by dual-energy X-ray absorptiometry (DXA) above average at all skeletal sites, with greatest scores observed at the lumbar spine. Trabecular bone score (TBS), an indirect measure of bone microarchitecture, also appears to be normal in HypoPT. By peripheral quantitative computed tomography (pQCT) of the radius, volumetric BMD at cancellous and cortical compartments, as well as cortical area and thickness, are greater in hypoparathyroid subjects than in controls. The use of high-resolution pQCT (HRpQCT) confirmed the increase in cortical volumetric BMD but demonstrated reduced cortical thickness, associated with lower cortical porosity in HypoPT. Trabeculae tend to be more numerous but thinner in hypoparathyroid subjects. It is not clear whether these structural and the dynamic skeletal abnormalities in HypoPT affect bone strength or fracture risk. Treatment of HypoPT with PTH leads to improvement in bone remodeling rate, variable changes in bone density, and a transient increase in estimated bone strength. The effect of PTH therapy on fracture risk remains unknown. This article reviews skeletal involvement and the effect of PTH treatment in patients with HypoPT, as assessed by DXA, TBS, QCT, and HRpQCT. Data on bone strength and fracture risk in HypoPT are also reviewed here.

The renal effects of SGLT2 inhibitors and a mini-review of the literature

Sodium-glucose linked transporter 2 (SGLT2) inhibitors are a new and promising class of antidiabetic agents which target renal tubular glucose reabsorption. Their action is based on the blockage of SGLT2 sodium-glucose cotransporters that are located at the luminal membrane of tubular cells of the proximal convoluted tubule, inducing glucosuria. It has been proven that they significantly reduce glycated hemoglobin (HbA1c), along with fasting and postprandial plasma glucose in patients with type 2 diabetes mellitus (T2DM). The glucosuria-induced caloric loss as well as the osmotic diuresis significantly decrease body weight and blood pressure, respectively. Given that SGLT2 inhibitors do not interfere with insulin action and secretion, their efficacy is sustained despite the progressive β-cell failure in T2DM. They are well tolerated, with a low risk of hypoglycemia. Their most frequent adverse events are minor: genital and urinal tract infections. Recently, it was demonstrated that empagliflozin presents a significant cardioprotective effect. Although the SGLT2 inhibitors' efficacy is affected by renal function, new data have been presented that some SGLT2 inhibitors, even in mild and moderate renal impairment, induce significant HbA1c reduction. Moreover, recent data indicate that SGLT2 inhibition has a beneficial renoprotective effect. The role of this review paper is to explore the current evidence on the renal effects of SGLT2 inhibitors.

Primary Hyperparathyroidism: The Influence of Bone Marrow Adipose Tissue on Bone Loss and of Osteocalcin on Insulin Resistance

OBJECTIVES

Bone marrow adipose tissue has been associated with low bone mineral density. However, no data exist regarding marrow adipose tissue in primary hyperparathyroidism, a disorder associated with bone loss in conditions of high bone turnover. The objective of the present study was to investigate the relationship between marrow adipose tissue, bone mass and parathyroid hormone. The influence of osteocalcin on the homeostasis model assessment of insulin resistance was also evaluated.

METHODS

This was a cross-sectional study conducted at a university hospital, involving 18 patients with primary hyperparathyroidism (PHPT) and 21 controls (CG). Bone mass was assessed by dual-energy x-ray absorptiometry and marrow adipose tissue was assessed by 1H magnetic resonance spectroscopy. The biochemical evaluation included the determination of parathyroid hormone, osteocalcin, glucose and insulin levels.

RESULTS

A negative association was found between the bone mass at the 1/3 radius and parathyroid hormone levels (r = -0.69; p<0.01). Marrow adipose tissue was not significantly increased in patients (CG = 32.8±11.2% vs PHPT = 38.6±12%). The serum levels of osteocalcin were higher in patients (CG = 8.6±3.6 ng/mL vs PHPT = 36.5±38.4 ng/mL; p<0.005), but no associations were observed between osteocalcin and insulin or between insulin and both marrow adipose tissue and bone mass.

CONCLUSION

These results suggest that the increment of adipogenesis in the bone marrow microenvironment under conditions of high bone turnover due to primary hyperparathyroidism is limited. Despite the increased serum levels of osteocalcin due to primary hyperparathyroidism, these patients tend to have impaired insulin sensitivity.

Management of Hypoparathyroidism: Summary Statement and Guidelines

OBJECTIVE

Hypoparathyroidism is a rare disorder characterized by hypocalcemia and absent or deficient PTH. This report presents a summary of current information about epidemiology, presentation, diagnosis, clinical features, and management and proposes guidelines to help clinicians diagnose, evaluate, and manage this disorder.

PARTICIPANTS

Participants in the First International Conference on the Management of Hypoparathyroidism represented a worldwide constituency with acknowledged interest and expertise in key basic, translational, and clinical aspects of hypoparathyroidism. Three Workshop Panels were constituted to address questions for presentation and discussion at the Conference held in Florence, Italy, May 7-9, 2015. At that time, a series of presentations were made, followed by in-depth discussions in an open forum. Each Workshop Panel also met in closed sessions to formulate the three evidence-based reports that accompany this summary statement. An Expert Panel then considered this information, developed summaries, guidelines, and a research agenda that constitutes this summary statement.

EVIDENCE

Preceding the conference, each Workshop Panel conducted an extensive literature search as noted in the individual manuscripts accompanying this report. All presentations were based upon the best peer-reviewed information taking into account the historical and current literature.

CONSENSUS PROCESS

This report represents the Expert Panel's synthesis of the conference material placed in a context designed to be relevant to clinicians and those engaged in cutting-edge studies of hypoparathyroidism.

CONCLUSIONS

This document not only provides a summary of our current knowledge but also places recent advances in its management into a context that should enhance future advances in our understanding of hypoparathyroidism.

Noninvasive Assessment of Skeletal Microstructure and Estimated Bone Strength in Hypoparathyroidism

In hypoparathyroidism, areal bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA) is above average, and skeletal indices by bone biopsy are abnormal. We used high-resolution peripheral quantitative computed tomography (HRpQCT) and finite element analyses (FEA) to further investigate skeletal microstructure and estimated bone strength. We studied 60 hypoparathyroid subjects on conventional therapy using DXA, HRpQCT, and FEA of the distal radius and tibia compared with normative controls from the Canadian Multicentre Osteoporosis Study. In hypoparathyroid women and men, areal BMD was above average at the lumbar spine and hip sites by DXA; radial BMD was also above average in hypoparathyroid women. Using HRpQCT, cortical volumetric BMD was increased in the hypoparathyroid cohort compared with controls at both the radius and tibia. Cortical porosity was reduced at both sites in pre- and postmenopausal women and at the tibia in young men with a downward trend at the radius in men. At the tibia, trabecular number was increased in premenopausal women and men and trabecular thickness was lower in women. Ultimate stress and failure load at both sites for the hypoparathyroid subjects were similar to controls. Using a linear regression model, at both radius and tibia, each increment in age decreased ultimate stress and failure load, whereas each increment in duration of hypoparathyroidism increased these same indices. These results provide additional evidence for the critical role of parathyroid hormone in regulating skeletal microstructure. Longer disease duration may mitigate the adverse effects of age on estimated bone strength in hypoparathyroidism.

The Use of Videogames, Gamification, and Virtual Environments in the Self-Management of Diabetes: A Systematic Review of Evidence

The use of videogames in healthcare interventions is gaining popularity, but there is still a gap in the understanding on how these types of interventions are used for the management of diabetes. The purpose of this review is to examine published research on the use of videogames for diabetes management. With the increased use of mobile technology, the review was expanded to understand whether games, gamification, and virtual environments can be used for diabetes self-management. Out of the 307 articles identified, only 10 articles met the inclusion criteria of the study. The duration of most studies was short, with small sample sizes. All interventions targeted behavioral changes examining risk reduction of diabetes-related risk and promotion of healthy behavior among study participants. Videogames appeared to be helpful tools for education in some interventions, whereas gamification and virtual environments increased extrinsic motivation and provided positive reinforcement. This review concludes by discussing the potential of using videogames and gamification for the self-management of diabetes.

Bone disease in hypoparathyroidism

Hypoparathyroidism is a rare disorder that may be acquired or inherited. Postsurgical hypoparathyroidism is responsible for the majority of acquired hypoparathyroidism. Bone disease occurs in hypoparathyroidism due to markedly reduced bone remodeling due to the absence or low levels of parathyroid hormone. Chronically reduced bone turnover in patients with hypoparathyroidism typically leads to higher bone mass than in age- and sex-matched controls. Whether this increased bone density reduces fracture risk is less certain, because while increased bone mineralization may be associated with increased brittleness of bone, this does not appear to be the case in hypoparathyroidism. Treatment of hypoparathyroidism with recombinant parathyroid hormone may reduce bone mineral density but simultaneously strengthen the mechanical properties of bone.

Development of an Aggregated System for Classifying Causes of Drug-Related Problems

Background: More than 20 different types of classification systems for drug-related problems (DRPs) and their causes have been developed. Classification is necessary to describe and assess clinical, organizational, and economic impacts of DRPs through documentation of collected data. However, many researchers have judged classification systems incomplete when describing their data, and have modified them or developed their own. This variability between systems has made study comparisons difficult. Objectives: To perform a category-by-category comparison of the content of selected DRP classification systems to construct an aggregated cause-of-DRP classification system containing the content of all systems. Method: DRP classification systems were identified after a literature review, with 7 chosen based on their use in varied health care settings, geographical diversity, frequency of use, and method of development. These systems were critically analyzed, and the content of each category was compared and aggregated where appropriate. A hierarchy of categories was constructed to include all content from all systems. Any modifications that previous studies may have made to the 7 systems were also cross-referenced to ensure that no concepts were missing from the newly aggregated system. Clinical examples to optimize application, and instructions for when or when not to use categories, were developed. Interrater agreement for classification of the causes of DRPs from 10 medication reviews was performed between 3 clinical pharmacists and the authors’ gold standard. Results: We found variation in developmental methods, category descriptions, number and types of categories, and validation methods between the 7 selected systems, together with intermingling of categories identified as causes of DRPs with DRPs themselves. A hierarchical classification system was constructed consisting of 9 cause-of-DRP categories, 33 subcategories, and 58 sub-subcategories, for which interrater agreements were 82.5%, 74.6%, and 58.8%, respectively. Conclusion: An aggregated classification system was constructed through a unique and transparent developmental process that may provide the most comprehensive description of causes of DRPs to date. This may facilitate teaching of pharmaceutical care, comparisons of clinical practice, and measurement of the effectiveness of pharmaceutical care interventions.

PTH(1-84) replacement therapy for the treatment of hypoparathyroidism

Hypoparathyroidism is a rare disease characterized by hypocalcemia and insufficient circulating levels of parathyroid hormone (PTH). Conventional therapy includes calcium and active vitamin D supplementation, often in large doses. Therapy with calcium and vitamin D, however, does not address certain problematic aspects of the disease, including abnormal bone metabolism and reduced quality of life. Hypoparathyroidism is the only classic endocrine deficiency disease for which the missing hormone, PTH, is not yet an approved treatment. PTH(1-84) may soon become a therapeutic option for patients with hypoparathyroidism. PTH (1-84) has been demonstrated to maintain serum calcium while reducing or eliminating requirements for calcium and active vitamin D supplementation. Data from bone densitometry, bone turnover markers and histomorphometry of bone biopsy specimens show positive structural and dynamic effects on the skeleton. PTH replacement therapy may also be associated with improved quality of life. PTH(1-84) replacement therapy for hypoparathyroidism is promising, although further acquisition of long-term data is needed.

Parathyroid hormone therapy for hypoparathyroidism

Hypoparathyroidism is a disease characterized by hypocalcemia and insufficient parathyroid hormone (PTH). It is a rare disorder that has been given an orphan disease designation in the United States and European Union. Hypoparathyroidism is the only endocrine deficiency disease for which the missing hormone, PTH, is not yet an approved therapy. Conventional therapy includes calcium and active vitamin D supplementation, often in large doses. Although serum calcium can be controlled with conventional therapy, it can be a challenge and, moreover, does not address other aspects of the disease, such as abnormal skeletal features and reduced quality of life. This review focuses on PTH replacement therapy in hypoparathyroidism, utilizing the full-length molecule PTH(1-84) as well as the fully active but truncated form PTH(1-34). PTH therapy addresses some aspects of the disease not ameliorated with conventional therapy.