Vitamin D supplementation after parathyroidectomy: effect on bone mineral density-a randomized double-blind study

Persistent elevated serum parathyroid hormone levels with normocalcaemia after parathyroidectomy: Secondary hyperparathyroidism or pseudo- hyperparathyroidism?

INTRODUCTION

This study aimed to determine the time to normalisation of postoperative parathyroid hormone levels after successful parathyroid surgery and to analyse the pathophysiology of postoperative normocalcaemic hyperparathyroidism.

METHOD

An observational retrospective study was conducted on a cohort of 186 patients who had undergone parathyroidectomy for primary hyperparathyroidism over a 5-year period. Demographic characteristics, surgical and histopathological data, bone densitometry (pre-and postoperative pharmacological treatment), creatinine plasma levels, and pre-and postoperative parathyroid hormone, calcium and vitamin D levels were recorded as predictive variables. The time to normalisation of the postoperative parathyroid hormone levels was recorded as the output variable. A univariate analysis was performed to investigate the factors related to the time to normalisation of parathyroid hormone levels.

RESULTS

The final study sample was comprised of 176 patients, 46 of which (26.1%) had elevated postoperative parathyroid hormone levels and normocalcaemia. The median time to normalisation of the postoperative parathyroid hormone levels was 6 months. The cumulative probability of having normal parathyroid hormone levels 30 months after surgery was 89%. The time to normalisation was associated only with preoperative parathyroid hormone levels (P = .007; HR: 0.998). Vitamin D and creatinine levels were not associated with time to normalisation of parathyroid hormone levels (P = .744).

CONCLUSIONS

Persistently elevated postoperative parathyroid hormone levels with normocalcaemia may occur in one-quarter of patients after parathyroidectomy. Parathyroid hormone levels normalise in up to 90% of cases by 30 months. A high preoperative parathyroid hormone level is predictive of postoperative normocalcaemic hyperparathyroidism, and vitamin D deficiency does not seem to influence the pathogenic mechanism.

Association of Obesity on Rates of Multiglandular Disease in Primary Hyperparathyroidism: A Cohort Study

INTRODUCTION

Primary hyperparathyroidism (PHPT) is more prevalent in populations with obesity. Obesity-related vitamin D deficiency may affect rates of multigland parathyroid disease, but this relationship is less clear. We aimed to assess the relationship between obesity and the rate of multigland disease in patients with PHPT.

METHODS

Patients who underwent parathyroidectomy from 2015 to 2021 for sporadic PHPT at a tertiary center were retrospectively analyzed. The primary outcome was rates of single-gland versus four-gland parathyroid hyperplasia in relation to obesity. Secondary outcomes included analysis of serum biochemistries [parathyroid hormone (PTH), calcium, 25(OH) vitamin D (25OHD)] before and 6 mo postoperatively based on obesity classification: no obesity (body mass index [BMI] <30 kg/m2), Class 1 (BMI 30-34.9 kg/m2), Class 2 (BMI 35-39.9 kg/m2), Class 3 (BMI ≥40 kg/m2). Statistical analysis was performed using Chi-square, Mann-Whitney U, and Kruskal-Wallis tests where applicable.

RESULTS

Of 2634 patients who underwent parathyroidectomy, a total of 1173 had obesity. Obesity did not confer any differences in the proportion of four-gland versus single-gland hyperplasia (25 versus 26%, P = 0.79). Compared to patients without obesity, preoperative PTH levels were higher in patients with Class 2 [86 (interquartile range [IQR] 66-118) versus 95 (IQR 70-137) pg/mL, P = 0.001] and Class 3 [86 (IQR 66-118) versus 104 (76-150) pg/mL, P < 0.001] obesity. Conversely, 25OHD before surgery was lower across obesity subclasses [no obesity: 36.0 (25.3-49.3), Class 1: 32.5 (24.0-46.0), Class 2: 32.9 (22.0-44.6), Class 3: 31.7 (20.4-45.0) ng/mL, P < 0.001]. Postoperative PTH and 25OHD improved in all cohorts. No calcium-related differences were found among patients based on obesity classification.

CONCLUSIONS

Obesity is not associated with an increased rate of four-gland hyperplasia in patients with PHPT, and therefore should not alter surgical management. The levels of 25OHD in patients with obesity should be monitored for vitamin deficiency preoperatively and postoperatively.

Parathyroidectomy Improves Bone Density in Women With Primary Hyperparathyroidism and Preoperative Osteopenia

CONTEXT

Osteoporosis and/or bone fractures are indications of parathyroidectomy in primary hyperparathyroidism (PHPT), especially in women. However, the benefit of surgery in patients with osteopenia remains unclear.

OBJECTIVE

To evaluate bone mineral density (BMD) and bone remodeling biomarkers changes 1 year after parathyroidectomy in women with PHPT.

DESIGN

In the prospective, monocentric, observational prospective cohort with primary hyperparathyroidism patients (CoHPT) cohort, women operated for sporadic PHPT since 2016 with ≥1 year follow-up were included. BMD (dual-X ray absorptiometry) and bone remodeling biomarkers [cross-linked C-telopeptide (CTX), procollagen type 1 N-terminal propeptide (P1NP), and bone-specific alkaline phosphatases] were assessed before and 1 year after parathyroidectomy.

SETTING

Referral center.

PATIENTS

A total of 177 women with PHPT (62.5 ± 13.3 years, 83.1% menopausal, 43.9% osteopenic, and 45.1% osteoporotic) were included.

INTERVENTION

Parathyroidectomy.

MAIN OUTCOME MEASURE

BMD change between before and 1 year after parathyroidectomy.

RESULTS

Parathyroidectomy resulted in significant increase in BMD and decrease in serum bone remodeling biomarker concentrations. In the 72 patients with baseline osteopenia, mean BMD significantly increased at the lumbar spine [+0.05 g/cm2 (95% confidence interval [CI], 0.03-0.07)], the femoral neck [+0.02 g/cm2 (95% CI 0.00-0.04)], the total hip [+0.02 g/cm2 (95% CI 0.01-0.02)], and the forearm [+0.01 (95% CI 0.00-0.02)], comparable to osteoporotic patients. Among osteopenic patients, those with individual BMD gain (>0.03 g/cm2) at ≥1 site had higher preoperative serum CTX, P1NP, and urine calcium concentrations than those without improvement.

CONCLUSION

Parathyroidectomy significantly improved BMD and remodeling biomarkers in women with osteopenia, thereby supporting the benefit of parathyroidectomy in these patients. Preoperative serum CTX and P1NP concentrations could be useful to predict expected BMD gain.

Ultrasound-guided microwave and radiofrequency ablation for primary hyperparathyroidism: a prospective, multicenter study

OBJECTIVES

To prospectively investigate the efficacy and safety of ultrasound (US)-guided microwave ablation (MWA) and radiofrequency ablation (RFA) for primary hyperparathyroidism (PHPT).

METHODS

We performed a prospective multicenter study of MWA and RFA for PHPT between August 2017 and October 2020 at five centers. Laboratory testing was performed pre- and post-ablation and followed for at least 6 months. The primary outcome was the cure rate. Secondary outcomes were complications and dynamic changes in serum levels of PTH, calcium, phosphorus, and ALP after ablation.

RESULTS

A total of 132 participants (mean age, 57.33 ± 13.90 years), with 141 parathyroid nodules (median maximal diameter, 1.55 cm) undergoing either MWA or RFA, were enrolled in the study. The technique success rate was 99.29% (140/141). The follow-up period was 6-36 months (median, 12 months). The cure rate was 80.30% (106/132). Pre-ablation PTH level was the independent factor associated with cure rate (Odds ratio (OR), 0.22; 95% CI, 0.07-0.69; p = 0.0090). There was no difference in cure rate between the MWA group and the RFA group (80.22% vs. 80.49%, p = 0.971). The only main complication was hoarseness (5.30%).

CONCLUSIONS

US-guided MWA and RFA for PHPT is an effective and safe procedure in the treatment of PHPT. Pre-ablation PTH level is the key factor affecting the cure rate after MWA and RFA.

KEY POINTS

• To our knowledge, this is the first prospective multicenter clinical trial with ultrasound-guided MWA and RFA for primary hyperparathyroidism. • There was no difference in cure rate between the MWA and RFA groups for primary hyperparathyroidism. The overall cure rate was 80.30%. • Pre-ablation PTH level was the independent factor associated with cure rate (odds ratio (OR), 0.22; 95% CI, 0.07-0.69; p = 0.0090).

Effect of supplemental vitamin D3 on bone mineral density: a systematic review and meta-analysis

Context

There is still controversy over the effect of vitamin D3 supplementation on bone health.

Objective

The effects of vitamin D3 supplementation on bone mineral density (BMD) and markers of bone turnover, as well as the dose-response relationship between vitamin D3 and bone health in adults, were evaluated.

Data Sources

The PubMed, Scopus, Cochrane, Web of Science, and AGRIS databases were searched for articles published through April 30, 2022. Thirty-nine of the 6409 records identified met the inclusion criteria

Data Extraction

Data were extracted from articles by 2 authors, and data extraction was cross-checked independently. A random-effects model was used to estimate the pooled effect size and the associated 95%CI for the effect of vitamin D3 for each outcome. A one-stage random-effects dose-response model was used to estimate the dose-response relationship between vitamin D3 supplementation and BMD.

Data Analysis

Results of meta-analysis showed a beneficial effect of vitamin D3 at the lumbar spine (standardized mean difference [SMD] = 0.06; 95%CI, 0.01–0.12) and femoral neck (SMD = 0.25; 95%CI, 0.09–0.41). Dose-response analysis revealed a linear relationship between vitamin D3 supplementation doses and BMD at the femoral neck, lumbar spine, and total hip sites. No significant effect of vitamin D3 supplementation on whole-body or total hip BMD was observed (P &gt; 0.05). Vitamin D3 supplementation significantly decreased BMD at both proximal and distal forearm (SMD = −0.16; 95%CI, −0.26 to −0.06). The variables of ethnicity, age, baseline 25-hydroxyvitamin D (25[OH]D), menopause status, vitamin D3 dosing frequency, and bone health status (P interaction = 0.02) altered the effect of vitamin D3 supplementation on BMD. Additionally, a nonlinear relationship between vitamin D3 supplement doses and markers of bone turnover was found.

Conclusion

A protective effect of vitamin D3 supplementation on BMD of the lumbar spine, femoral neck, and total hip is implicated.

Systematic Review Registration

PROSPERO registration number CRD42017054132.

Risk factors influencing cure of ultrasound-guided microwave ablation for primary hyperparathyroidism

OBJECTIVE

To evaluate the potential risk factors influencing cure rate of ultrasound-guided microwave ablation (MWA) for primary hyperparathyroidism (PHPT).

MATERIALS AND METHODS

Seventy five patients (25 males and 50 females; mean age, 56.80 ± 12.34; age range, 26-85) with PHPT undergoing MWA under ultrasound guidance were enrolled between May 2017 and December 2020. The cure rate and complications were evaluated after treatment. The potential factors influencing cure rate of ultrasound-guided MWA for PHPT were analyzed by univariate and multivariate binary logistic regression.

RESULTS

Fifty six of 75 patients had normal PTH and serum calcium levels after at least 6 months after one session MWA, and the cure rate was 74.7% (56/75). 6 uncured patients received the second session MWA during follow-up, and the cure rate achieved 81.3% (61/75) after the second session MWA. Voice changes occurred in 4 patients (5.33%) and recovered within 3 months after ablation without special treatment. Nodule volume was the independent risk factor associated with cure in PHPT patients undergoing MWA, whether after one session (p = 0.0224; odds ratio, 0.67) or the second session MWA (p = 0.0408; odds ratio, 0.74). The cutoff value for nodule volume in predicting the cure was 0.96 cm³ (one session: sensitivity, 76.8%; specificity, 73.7%; the second session: sensitivity, 72.1%; specificity, 71.4%).

CONCLUSION

In conclusion, parathyroid nodule volume was the independent risk factor associated with cure in PHPT patients undergoing MWA.

[The clinical practice guidelines for primary hyperparathyroidism, short version]

Primary hyperparathyroidism (PHPT) is an endocrine disorder of parathyroid glands characterized by excessive secretion of parathyroid hormone (PTH) with an upper normal or elevated blood calcium level. Classical PHPT refers to a symptomatic, multi-system disorder, wich can lead to a significant decrease in the quality of life, disability of patients, and even an increased risk of premature death. Hypercalcemia and the catabolic effect of PTH on various cells are considered as the main pathogenetic mechanisms of the PHPT associated complications. In the last two decades, there has been an increase in the incidence of PHPT, mainly due to the mild forms of the disease, primarily due to the routine calcium screening in North America, Western Europe and, Asia. High prevalence of the disease, as well as the variety of clinical manifestations, cause the attention of different specialists - physicians, rheumatologists, urologists, nephrologists, cardiologists and other doctors. This review cover the main issues of Russian guidelines for the management of PHPT, approved in 2020, including laboratory and instrumental methods, differential diagnosis, surgical and conservative approach, short-term and long-term follow-up. This guidelines also include the recommendations for special groups of patients with hereditary forms of PHPT, parathyroid carcinoma, PHPT during pregnancy.

[Normocalcemic with elevated post-operative parathormone in primary hyperpara-thyroidism: 9 case reports and literature review]

OBJECTIVE

To summarize and analyze the clinical characteristics of primary hyperpara-thyroidism (PHPT) with normocalcemic parathormone elevation (NPE) after surgical treatment, so as to improve the therapeutic ability and standardized post-operative follow-up of PHPT patients.

METHODS

Nine patients who were diagnosed with PHPT in the Department of Endocrinology of China-Japan Friendship Hospital from August 2017 to November 2019 were selected as the subjects. They all developed NPE within 6 months after surgical treatment. The clinical features and outcomes were collected and analyzed retrospectively, in addition, the related literature was reviewed.

RESULTS

Clinical features: among the 9 patients, 6 were middle-aged and elderly females and 3 were male. The main clinical manifestations were bone pain, kidney stones, nausea and fatigue except for one case of asymptomatic PHPT. Pre-operative examination showed high serum calcium [(3.33±0.48) mmol/L], low serum phosphorus [0.76 (0.74, 0.78) mmol/L], high 24-hour urinary calcium [8.1(7.8, 12.0) mmol/24 h], obviously elevated intact PTH [(546.1±257.7) ng/L], vitamin D deficiency [25-hydroxyvitamin D₃ (21.0±5.7) nmol/L]. Serum levels of bone alkaline phosphatase [7 patients 41.3(38.6, 68.4) μg/L, 2 patients >90 μg/L] and N-terminal midcourse osteocalcin (>71.4 μg/L) were significantly elevated. The estimated glomerular filtration rate decreased in 2 patients. Imaging examination: 7 patients had osteoporosis. Renal calculi were found in 3 patients by renal ultrasound. Imaging examination of parathyroid glands found definite lesions in all the patients, including 2 cases of multiple lesions and 7 cases of single lesions.

TREATMENT AND OUTCOME

two patients underwent parathyroidectomy, while other patients were treated with microwave thermal ablation. PTH increased 1 month after therapy [(255.0±101.4) ng/L], and no recurrent lesions were found by parathyroid ultrasound. After combined treatment with cal-cium and vitamin D for six months, PTH decreased significantly and the level of serum calcium remained normal at anytime during the follow-up period.

CONCLUSION

The occurrence of postoperative NPE may be related to the higher pre-operative PTH, vitamin D deficiency and lower creatinine clearance. However, NPE may not predict recurrent hyperthyroidism or incomplete parathyroidectomy. Adequate calcium and vitamin D supplementation after surgery seems to be beneficial for patients with NPE. Post-operative follow-up of PHPT patients should be standardized to prevent and treat post-operative NPE.

Primary hyperparathyroidism: should surgery be performed on all patients? Current evidence and residual uncertainties

Primary hyperparathyroidism (pHPT) is the third most common endocrine disease and is characterized by hypercalcaemia and elevated or inappropriately 'normal' levels of the parathyroid hormone (PTH). The main target organs of PTH are the skeletal system and the kidneys. Before the 1970s, pHPT was a rarely detected disease associated with notable morbidity and premature mortality. Introduction of biochemical screening, allowing for a wide range of indications, has contributed to the detection of the full spectrum of the disease. A new entity with an isolated elevation of PTH, normocalcaemic HP, has emerged and is currently being explored. The highest incidence of pHPT, 3-5%, is observed amongst women, and the prevalence increases with age. The female-to-male ratio is 3-4 : 1 except in younger patients where distribution is equal and known hereditary causes account for approximately 10% of the cases. In the last few decades, it has become evident that fewer patients than previously believed are truly asymptomatic. The cause of pHPT is often a benign tumour, a parathyroid adenoma, and the only definite treatment is parathyroidectomy (PTX). No medical treatment, single or combined, can achieve a curing of pHPT. Recent data indicate that PTX, despite being proven to be cost-effective compared to conservative treatment, is underutilized, especially in elderly pHPT patients. The decision of PTX should always be based on a safe diagnosis, and the potential benefits of curative treatment should not be outweighed by the risks of surgery or anaesthesia.

Effects of vitamin D supplementation on musculoskeletal health: a systematic review, meta-analysis, and trial sequential analysis

BACKGROUND

The effects of vitamin D on fractures, falls, and bone mineral density are uncertain, particularly for high vitamin D doses. We aimed to determine the effect of vitamin D supplementation on fractures, falls, and bone density.

METHODS

In this systematic review, random-effects meta-analysis, and trial sequential analysis, we used findings from literature searches in previously published meta-analyses. We updated these findings by searching PubMed, Embase, and Cochrane Central on Sept 14, 2017, and Feb 26, 2018, using the search term "vitamin D" and additional keywords, without any language restrictions. We assessed randomised controlled trials of adults (>18 years) that compared vitamin D with untreated controls, placebo, or lower-dose vitamin D supplements. Trials with multiple interventions (eg, co-administered calcium and vitamin D) were eligible if the study groups differed only by use of vitamin D. We excluded trials of hydroxylated vitamin D analogues. Eligible studies included outcome data for total or hip fractures, falls, or bone mineral density measured at the lumbar spine, total hip, femoral neck, total body, or forearm. We extracted data about participant characteristics, study design, interventions, outcomes, funding sources, and conflicts of interest. The co-primary endpoints were participants with at least one fracture, at least one hip fracture, or at least one fall; we compared data for fractures and falls using relative risks with an intention-to-treat analysis using all available data. The secondary endpoints were the percentage change in bone mineral density from baseline at lumbar spine, total hip, femoral neck, total body, and forearm.

FINDINGS

We identified 81 randomised controlled trials (n=53 537 participants) that reported fracture (n=42), falls (n=37), or bone mineral density (n=41). In pooled analyses, vitamin D had no effect on total fracture (36 trials; n=44 790, relative risk 1·00, 95% CI 0·93-1·07), hip fracture (20 trials; n=36 655, 1·11, 0·97-1·26), or falls (37 trials; n=34 144, 0·97, 0·93-1·02). Results were similar in randomised controlled trials of high-dose versus low-dose vitamin D and in subgroup analyses of randomised controlled trials using doses greater than 800 IU per day. In pooled analyses, there were no clinically relevant between-group differences in bone mineral density at any site (range -0·16% to 0·76% over 1-5 years). For total fracture and falls, the effect estimate lay within the futility boundary for relative risks of 15%, 10%, 7·5%, and 5% (total fracture only), suggesting that vitamin D supplementation does not reduce fractures or falls by these amounts. For hip fracture, at a 15% relative risk, the effect estimate lay between the futility boundary and the inferior boundary, meaning there is reliable evidence that vitamin D supplementation does not reduce hip fractures by this amount, but uncertainty remains as to whether it might increase hip fractures. The effect estimate lay within the futility boundary at thresholds of 0·5% for total hip, forearm, and total body bone mineral density, and 1·0% for lumbar spine and femoral neck, providing reliable evidence that vitamin D does not alter these outcomes by these amounts.

INTERPRETATION

Our findings suggest that vitamin D supplementation does not prevent fractures or falls, or have clinically meaningful effects on bone mineral density. There were no differences between the effects of higher and lower doses of vitamin D. There is little justification to use vitamin D supplements to maintain or improve musculoskeletal health. This conclusion should be reflected in clinical guidelines.

FUNDING

Health Research Council of New Zealand.

Elevated parathyroid hormone levels after successful parathyroidectomy for primary hyperparathyroidism: a clinical review

INTRODUCTION

Surgery for primary hyperparathyroidism (PHPT) is traditionally deemed to be successful if serum calcium levels return to normal 6 months after parathyroidectomy. Regular monitoring of serum calcium and parathyroid hormone (PTH) in the follow-up of patients after parathyroidectomy for PHPT has drawn attention to the presence of a normocalcemic group of patients with elevated PTH (NCePTH) during the post-operative period. The etiological factors and mechanisms underlying this condition, its consequences, and the possibility of treatment are the object of this study.

MATERIALS AND METHODS

We conducted an unlimited PubMed search updated on March 31, 2017, which yielded 1628 results. We selected 37 articles, 33 of which included cases of NCePTH in their series and 23 performed statistical studies to assess factors associated with NCePTH.

RESULTS

The maximum mean prevalence of NCePTH in the various series was 23.5%, ranging from 3 to 46%. Many factors were associated with NCePTH. The most important were higher pre-operative PTH, low pre-operative 25 (OH) D3, lower pre-operative creatinine clearance and greater adenoma weight. The origin of NCePTH may be multifactorial, since several factors were implicated in the etiology. NCePTH does not seem to be related to an increase in PHPT recurrence, although this possibility should not be dismissed. Vitamin D deficiency should be corrected. Treatment with calcium supplements seems to be clearly beneficial.

CONCLUSION

The prevalence of NCePTH is high. The causes of secondary hyperparathyroidism should be investigated carefully. Patients require treatment and long-term follow-up.

Diffuse parathyroid hormone expression in parathyroid tumors argues against important functional tumor subclones

OBJECTIVE

Primary hyperparathyroidism is usually characterized by a monoclonal parathyroid tumor secreting excess parathyroid hormone (PTH). The main regulator of PTH secretion is calcium and the calcium-PTH set point is shifted in parathyroid tumor cells. We sought to investigate the relationship between tumor PTH and PTH mRNA expression and clinical presentation as well as the regulatory factors including phosphate, vitamin D, and fibroblast growth factor 23.

DESIGN

A total of 154 parathyroid tumors were analyzed by PTH immunohistochemistry and chromogenic in situ hybridization of PTH mRNA. A subset of samples (n = 34) was analyzed using quantitative real-time PCR.

RESULTS

Low tumor PTH mRNA level was significantly associated with low tumor PTH immunoreactivity (P = 0.026), but the two did not correlate with regard to histological distribution within individual tumors. Tumors displaying reduced PTH mRNA levels as compared with normal rim were significantly larger (P = 0.013) and showed higher expression of the calcium-sensing receptor (CASR) (P = 0.046). Weaker tumor PTH mRNA level was significantly associated with higher concentration of circulating 25-hydroxyvitamin D (P = 0.005). No significant correlation was seen between PTH immunoreactivity and patient biochemistry. Tumor weight was strongly associated with circulatory concentrations of calcium and PTH.

CONCLUSIONS

No areas with apparently higher PTH expression were identified, perhaps suggesting that hyper functioning parathyroid tumor subclones should be rare. Circulating 25-hydroxyvitamin D levels may influence tumor PTH expression in vivo. If PTH immunoreactivity reflects the tumor calcium-PTH set point, our data imply that the main determinant of disease severity should be tumor weight.

Calcium plus vitamin D supplementation and risk of fractures: an updated meta-analysis from the National Osteoporosis Foundation

The aim was to meta-analyze randomized controlled trials of calcium plus vitamin D supplementation and fracture prevention. Meta-analysis showed a significant 15 % reduced risk of total fractures (summary relative risk estimate [SRRE], 0.85; 95 % confidence interval [CI], 0.73-0.98) and a 30 % reduced risk of hip fractures (SRRE, 0.70; 95 % CI, 0.56-0.87).

INTRODUCTION

Calcium plus vitamin D supplementation has been widely recommended to prevent osteoporosis and subsequent fractures; however, considerable controversy exists regarding the association of such supplementation and fracture risk. The aim was to conduct a meta-analysis of randomized controlled trials [RCTs] of calcium plus vitamin D supplementation and fracture prevention in adults.

METHODS

A PubMed literature search was conducted for the period from July 1, 2011 through July 31, 2015. RCTs reporting the effect of calcium plus vitamin D supplementation on fracture incidence were selected from English-language studies. Qualitative and quantitative information was extracted; random-effects meta-analyses were conducted to generate summary relative risk estimates (SRREs) for total and hip fractures. Statistical heterogeneity was assessed using Cochran's Q test and the I (2) statistic, and potential for publication bias was assessed.

RESULTS

Of the citations retrieved, eight studies including 30,970 participants met criteria for inclusion in the primary analysis, reporting 195 hip fractures and 2231 total fractures. Meta-analysis of all studies showed that calcium plus vitamin D supplementation produced a statistically significant 15 % reduced risk of total fractures (SRRE, 0.85; 95 % confidence interval [CI], 0.73-0.98) and a 30 % reduced risk of hip fractures (SRRE, 0.70; 95 % CI, 0.56-0.87). Numerous sensitivity and subgroup analyses produced similar summary associations. A limitation is that this study utilized data from subgroup analysis of the Women's Health Initiative.

CONCLUSIONS

This meta-analysis of RCTs supports the use of calcium plus vitamin D supplements as an intervention for fracture risk reduction in both community-dwelling and institutionalized middle-aged to older adults.

Combination therapy of Chinese herbal medicine Fructus Ligustri Lucidi with high calcium diet on calcium imbalance induced by ovariectomy in mice

CONTEXT

Our previous biological study demonstrated that Fructus Ligustri Lucidi (FLL), the fruit of Ligustrum lucidum Ait. (Oleaceae), could be used to maintain calcium balance and prevent age-related osteoporosis since it effectively decreased calcium loss and increased calcium retention in rats.

OBJECTIVE

This study investigates the combination effect of the Chinese herbal medicine FLL and a high calcium diet on calcium imbalance induced by ovariectomy in mice.

MATERIALS AND METHODS

The ovariectomized (OVX) mice were orally treated with vehicle, FLL extract (700 mg/kg), milk powder (5 g/mice) fortified with calcium (1.0% Ca) and the combination of FLL with milk powder. After 6 weeks of treatment, urine, serum, and tibia were preserved for biochemical analysis and kidneys were taken for gene expression analysis.

RESULTS

The combination treatment of FLL and a high calcium diet significantly increased bone calcium content (6.80 ± 0.34 mg) by 22% (p < 0.05) and decreased urine calcium excretion (0.099 ± 0.009 mg/mg) by 62% (p < 0.01) as compared with those of the OVX group (bone Ca, 5.57 ± 0.31 mg; urine Ca/Cr, 0.261 ± 0.017 mg/mg). The mRNA expression of renal calcium-binding protein-9k (CaBP-9k) and calcium-sensing receptor (CaSR) in combination treatment group was significantly up-regulated and down-regulated, respectively, as compared with those of the OVX group.

CONCLUSION

The beneficial effects of this combination therapy on calcium balance of OVX mice were, at least partially, attributed to its regulation on mRNA expression of CaBP-9k and CaSR in kidney.

The effect of bovine parathyroid hormone withdrawal on MC3T3-E1 cell proliferation and phosphorus metabolism

Hypocalcemia and hypophosphatemia are common complications after parathyroidectomy (PTX). Sudden removal of high circulating levels of parathyroid hormone (PTH) causes decreased osteoclastic resorption resulting in a decreased bone remodeling space. These phenomena are likely due to an increased influx of calcium and phosphorus into bone. However, there are currently no data to support this hypothesis. In this study, we found that PTX significantly reduced levels of PTH, calcium and phosphate. Compared with preoperative levels, after 1 year, postoperative PTH, calcium and phosphate levels were 295.6 ± 173.7 pg/mL (P < 0.05), 86.62 ± 15.98 mg/dL (P < 0.05) and 5.56 ± 2.03 mg/dL (P < 0.05), respectively. We investigated continuous bovine PTH administration as well as withdrawal of bovine PTH stimulation in the mouse osteoblast precursor cell line MC3T3-E1. MC3T3-E1 cells were cultured with continuous bovine PTH treatment for 20 days or with transient bovine PTH treatment for 10 days. High doses of continuous bovine PTH exposure strongly reduced cell proliferation, alkaline phosphatase activity and the number of mineralized calcium nodules. However, withdrawal of bovine PTH (100 ng/mL) significantly increased the number of mineralized calcium nodules and caused a rapid decline in calcium and phosphorus content of culture medium. In conclusion, continuous exposure to bovine PTH inhibited osteoblast differentiation and reduced the formation of mineralized nodules. However, this inhibition was removed and mineralized nodule formation resumed with withdrawal of bovine PTH. According to the results of our clinical examinations and in vitro experiments, we hypothesize that the sudden removal of high levels of PTH may cause an increased influx of calcium and phosphorus into bone after PTX.

Tumour nuclear oestrogen receptor beta 1 correlates inversely with parathyroid tumour weight

Primary hyperparathyroidism (PHPT) is a common endocrinopathy, frequently caused by a parathyroid adenoma, rarely by a parathyroid carcinoma that lacks effective oncological treatment. As the majority of cases are present in postmenopausal women, oestrogen signalling has been implicated in the tumourigenesis. Oestrogen receptor beta 1 (ERB1) and ERB2 have been recently identified in parathyroid adenomas, the former inducing genes coupled to tumour apoptosis. We applied immunohistochemistry and slide digitalisation to quantify nuclear ERB1 and ERB2 in 172 parathyroid adenomas, atypical adenomas and carcinomas, and ten normal parathyroid glands. All the normal parathyroid glands expressed ERB1 and ERB2. The majority of tumours expressed ERB1 (70.6%) at varying intensities, and ERB2 (96.5%) at strong intensities. Parathyroid carcinomas expressed ERB1 in three out of six cases and ERB2 in five out of six cases. The intensity of tumour nuclear ERB1 staining significantly correlated inversely with tumour weight (P=0.011), and patients whose tumours were classified as ERB1-negative had significantly greater tumour weight as well as higher serum calcium (P=0.002) and parathyroid hormone levels (P=0.003). Additionally, tumour nuclear ERB1 was not expressed differentially with respect to sex or age of the patient. Levels of tumour nuclear ERB2 did not correlate with clinical characteristics. In conclusion, decreased ERB1 immunoreactivity is associated with increased tumour weight in parathyroid adenomas. Given the previously reported correlation with tumour-suppressive signalling, selective oestrogen receptor modulation (SERMs) may play a role in the treatment of parathyroid carcinomas. Future studies of SERMs and oestrogen treatment in PHPT should consider tumour weight as a potential factor in pharmacological responsiveness.

Health-related quality of life after successful surgery for primary hyperparathyroidism: no additive effect from vitamin D supplementation: results of a double-blind randomized study

OBJECTIVE

Vitamin D insufficiency is common in primary hyperparathyroidism (pHPT). Patients with pHPT frequently have a reduced health-related quality of life (HRQoL). Our objectives were to evaluate whether HRQoL in pHPT is associated with vitamin D insufficiency and whether vitamin D supplementation after parathyroidectomy (PTX) could improve HRQoL.

DESIGN

A randomized, double-blind study (ClinicalTrials.gov identifier: NCT00982722).

METHODS

The study included 150 pHPT patients randomized, 6 weeks after PTX, to daily treatment with either cholecalciferol 1600 IU and calcium carbonate 1000 mg (D+) or calcium carbonate alone (D-). HRQoL was estimated with SF-36 before and after PTX and after 12 months of study medication.

RESULTS

Three-quarters (77%) of the pHPT patients had vitamin D insufficiency, defined as 25OHD <50 nmol/l. The pHPT patients scored lower than a reference population in all domains of SF-36. A total of 135 patients completed the entire study period. Improvements in nearly all domains were registered at the follow-up 6 weeks after PTX. At the end of the study medication period, the D+ group had a significantly higher median serum (s-) 25OHD concentration (76 (65; 93) (lower; upper interquartile ranges) vs 48 (40; 62) nmol/l, P<0.001) and a lower plasma (p-) parathyroid hormone concentration (40 (34; 52) vs 49 (38; 66) ng/l, P=0.01) than the D- group. The improvements in HRQoL remained unchanged at the follow-up 1 year after PTX. Postoperative vitamin D supplementation had no obvious effect on HRQoL.

CONCLUSION

PTX resulted in significant improvements in HRQoL. Despite a high prevalence of vitamin D insufficiency, 1 year of postoperative vitamin D supplementation had no obvious beneficial effect on HRQoL.

Bone Involvement in Primary Hyperparathyroidism and Changes After Parathyroidectomy

Parathyroid hormone (PTH) is produced and secreted by the parathyroid glands and has primary effects on kidney and bone. During the pathological growth of one or more parathyroid glands, the plasma level of PTH increases and causes primary hyperparathyroidism (PHPT). This disease is normally characterised by hyperparathyroid hypercalcaemia. In PHPT a continuously elevated PTH stimulates the kidney and bone causing a condition with high bone turnover, elevated plasma calcium and increased fracture risk. If bone resorption is not followed by a balanced formation of new bone, irreversible bone loss may occur in these patients. Medical treatment can help to minimise the loss of bone but the cure of PHPT is by parathyroidectomy. After operation, bone mineral density increases during the return to normal bone metabolism. Supplementation with calcium and vitamin D after operation may improve the normalisation to normal bone metabolism with a secondary reduction in fracture risk.