PTH and Vitamin D

Serum nuclear factor IB as a novel and noninvasive indicator in the diagnosis of secondary hyperparathyroidism

BACKGROUND

Chronic renal failure (CRF) referred to chronic progressive renal parenchymal damage caused by various causes, with metabolite retention and imbalance of water, electrolyte, and acid-base balance as the main clinical manifestations. Secondary hyperparathyroidism (sHPT) was a common complication in maintenance hemodialysis patients with CRF. Nuclear factor IB (NFIB) was a newly found tumor suppressor gene in various cancers. The present study aimed to illustrate the role of NFIB in sHPT clinical diagnosis and treatment response.

METHODS

A retrospective, case-control study, including 189 patients with sHPT and 106 CRF patients without sHPT, compared with 95 controls. Serum NFIB and 1,25(OH)₂ D₃ levels were measured by RT-qPCR and ELISAs, respectively. ROC analysis was conducted to verify the diagnostic value of NFIB in sHPT. Spearman's correlation analysis was conducted to verify the association between NFIB and bone mineral density (BMD) scores. After 6 months of treatment, the variance of NFIB and 1,25(OH)₂ D₃ in different groups was recorded.

RESULTS

The expression of NFIB was significantly lower in serum samples from sHPT and non-sHPT CRF patients, compared to controls. Clinicopathological information verified sHPT was associated with NFIB, parathyroid hormone (PTH), serum calcium, serum phosphorus, time of dialysis, and serum 1,25(OH)₂ D₃ levels. Spearman's correlation analysis illustrated the positive correlation between NFIB levels and BMD scores. At receiver operator characteristic (ROC) curve analysis, the cutoff of 1.6508 for NFIB was able to identify patients with sHPT from healthy controls; meanwhile, NFIB could also discriminate sHPT among CRF patients as well (cutoff = 1.4741). Furthermore, we found that during 6 months of treatment, NFIB levels were gradually increased, while PTH and serum P levels were decreased.

CONCLUSIONS

Serum NFIB was a highly accurate tool to identify sHPT from healthy controls and CRF patients. Due to its simplicity, specificity, and sensitivity, this candidate can be proposed as a first-line examination in the diagnostic workup in sHPT.

Parathyroid Hormone Gene and Genes Involved in the Maintenance of Vitamin D Levels Association with Mandibular Retrognathism

In this study we evaluated whether single nucleotide polymorphisms (SNPs) in the genes encoding PTH, VDR, CYP24A1, and CYP27B1 were associated with mandibular retrognathism (MR). Samples from biologically-unrelated Brazilian patients receiving orthodontic treatment were included in this study. Pre-orthodontic lateral cephalograms were used to determine the phenotype. Patients with a retrognathic mandible were selected as cases and those with an orthognathic mandible were selected as controls. Genomic DNA was used for genotyping analysis of SNPs in PTH (rs694, rs6256, and rs307247), VDR (rs7975232), CYP24A1 (rs464653), and CYP27B1 (rs927650). Chi-squared or Fisher’s tests were used to compare genotype and allele distribution among groups. Haplotype analysis was performed for the SNPs in PTH. The established alpha was p < 0.05. Multifactor dimensionality reduction (MDR) was used to identify SNP–SNP interactions. A total of 48 (22 males and 26 females) MR and 43 (17 males and 26 females) controls were included. The linear mandibular and the angular measurements were statistically different between MR and controls (p < 0.05). In the genotype and allele distribution analysis, the SNPs rs694, rs307247, and rs464653 were associated with MR (p < 0.05). MDR analyses predicted the best interaction model for MR was rs694–rs927650, followed by rs307247–rs464653–rs927650. Some haplotypes in the PTH gene presented statistical significance. Our results suggest that SNPs in PTH, VDR, CYP24A1, and CYP27B1 genes are associated with the presence of mandibular retrognathism.

Pleckstrin homology (PH) domain and Leucine Rich Repeat Phosphatase 1 (Phlpp1) Suppresses Parathyroid Hormone Receptor 1 (Pth1r) Expression and Signaling During Bone Growth

Endochondral ossification is tightly controlled by a coordinated network of signaling cascades including parathyroid hormone (PTH). Pleckstrin homology (PH) domain and leucine rich repeat phosphatase 1 (Phlpp1) affects endochondral ossification by suppressing chondrocyte proliferation in the growth plate, longitudinal bone growth, and bone mineralization. As such, Phlpp1-/- mice have shorter long bones, thicker growth plates, and proportionally larger growth plate proliferative zones. The goal of this study was to determine how Phlpp1 deficiency affects PTH signaling during bone growth. Transcriptomic analysis revealed greater PTH receptor 1 (Pth1r) expression and enrichment of histone 3 lysine 27 acetylation (H3K27ac) at the Pth1r promoter in Phlpp1-deficient chondrocytes. PTH (1-34) enhanced and PTH (7-34) attenuated cell proliferation, cAMP signaling, cAMP response element-binding protein (CREB) phosphorylation, and cell metabolic activity in Phlpp1-inhibited chondrocytes. To understand the role of Pth1r action in the endochondral phenotypes of Phlpp1-deficient mice, Phlpp1-/- mice were injected with Pth1r ligand PTH (7-34) daily for the first 4 weeks of life. PTH (7-34) reversed the abnormal growth plate and long-bone growth phenotypes of Phlpp1-/- mice but did not rescue deficits in bone mineral density or trabecular number. These results show that elevated Pth1r expression and signaling contributes to increased proliferation in Phlpp1-/- chondrocytes and shorter bones in Phlpp1-deficient mice. Our data reveal a novel molecular relationship between Phlpp1 and Pth1r in chondrocytes during growth plate development and longitudinal bone growth. © 2021 American Society for Bone and Mineral Research (ASBMR).

In Terms of Nutrition, the Most Suitable Method for Bariatric Surgery: Laparoscopic Sleeve Gastrectomy or Roux-en-Y Gastric Bypass? A Systematic Review and Meta-analysis

This study assesses the differences in postoperative nutritional status between laparoscopic sleeve gastrectomy (LSG) and laparoscopic Roux-en-Y gastric bypass (LRYGB). We searched the literature from PubMed, Web of Science, Embase, and the Cochrane Library database. Twenty-nine articles were included, with a total of 5437 obese patients. After bariatric surgery, the LSG group had less anemia and iron deficiency anemia than the LRYGB group. The serum iron, ferritin deficiency, and vitamin B₁₂ rates after LSG were lower than patients receiving LRYGB. And PTH and serum phosphorus concentration of patients after LSG were both lower than those after LRYGB. The postoperative results of LSG were better than that of LRYGB. Therefore, we recommend LSG for a better postoperative nutrition, but only for reference.

Vitamin K and D Supplementation and Bone Health in Chronic Kidney Disease-Apart or Together?

Vitamin K (VK) and vitamin D (VD) deficiency/insufficiency is a common feature of chronic kidney disease (CKD), leading to impaired bone quality and a higher risk of fractures. CKD patients, with disturbances in VK and VD metabolism, do not have sufficient levels of these vitamins for maintaining normal bone formation and mineralization. So far, there has been no consensus on what serum VK and VD levels can be considered sufficient in this particular population. Moreover, there are no clear guidelines how supplementation of these vitamins should be carried out in the course of CKD. Based on the existing results of preclinical studies and clinical evidence, this review intends to discuss the effect of VK and VD on bone remodeling in CKD. Although the mechanisms of action and the effects of these vitamins on bone are distinct, we try to find evidence for synergy between them in relation to bone metabolism, to answer the question of whether combined supplementation of VK and VD will be more beneficial for bone health in the CKD population than administering each of these vitamins separately.

Predictors of circulating vitamin D levels in healthy mid-life Singaporean women

Vitamin D levels were lowest in Indian and Malay compared to Chinese women, and in younger and employed women. The main reason for hypovitaminosis D in study women was deficient cutaneous production. Supplementation in regions with abundant sunshine should consider ethnicity and opportunities for exposure to sunlight.

INTRODUCTION

Little is known about variations in circulating vitamin D levels in multiethnic mid-life women living in communities with year-round sunlight. Our study describes the circulating vitamin D levels and their sociodemographic predictors in mid-life Singaporean women.

METHODS

Prospective cross-sectional study of healthy Singaporean women, age 45-69 years, who were not consuming vitamin D supplements. Total 25-hydroxyvitaminD [25(OH)D], the sum of 25(OH)D₂ and 25(OH)D₃, was measured by liquid chromatography-tandem mass spectrometry.

RESULTS

The analytic cohort of 721 women, mean age 55.2±6.0 (±SD) years, was of Chinese (82%), Indian (11%), and Malay (7%) ethnicity. Their mean 25(OH)D level was 24.8±7.8ng/mL. One-third (32.6%) of the women had deficient 25(OH)D (≤20ng/mL) and 3.5% were severely deficient (<12ng/mL). 25(OH)D₃ comprised 98% of the total circulating 25(OH)D level. Adjusted mean total 25(OH)D levels were significantly lower for women of Indian and Malay (vs Chinese) ethnicity, who were premenopausal or working outside the home. Indian and Malay women had higher odds (adjusted OR 5.58 (95% CI 3.22, 9.87) and 3.83 (95% CI 1.97, 7.57), respectively) of low 25(OH)D compared to Chinese women. Obesity was not an independent predictor of low 25(OH)D, as its strong crude association was confounded by ethnicity. The adjusted odds of low 25(OH)D was reduced in women ≥65 years (adjusted OR 0.37 (95% CI 0.14, 0.87)) compared to those aged 45-55 years.

CONCLUSION

One-third of mid-life Singaporean women were 25(OH)D deficient, and the major independent predictors of deficiency were Indian or Malay ethnicity and younger age. Vitamin D supplementation in mid-life women should be targeted to those with documented deficiency or limited cutaneous production.

Effects of a Single Oral Megadose of Vitamin D3 on Inflammation and Oxidative Stress Markers in Overweight and Obese Women: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

AIM

The study aimed to evaluate the effects of vitamin D3 (VD3) supplementation on inflammation and oxidative stress markers in overweight and obese women with deficiency or insufficiency of vitamin D.

METHODS

Twenty-nine overweight or obese women who had a deficiency or insufficiency of vitamin D were placed into two groups according to VD3 intervention. Patients in the supplemented group received a single oral megadose of VD3 (VD3, n=14). Patients in placebo group received a single oral identical capsule without vitamin D (placebo, n = 15). Anthropometric and biochemical variables were assessed at baseline and after 4-weeks intervention.

RESULTS

Anthropometric variables (waist circumference, waist-hip ratio, waist-height ratio and body mass index) were similar between groups (p > 0.05). VD3 supplementation increased the serum levels of 25-hydroxyvitamin D (p=0.000), malondialdehyde (p=0.021) and C-reactive protein (p=0.043) in overweight and obese women. Additionally, VD3 supplementation reduced the serum levels of aspartate aminotransferase (AST, p=0.035), alanine aminotransferase (ALT, p<0.0001) in overweight and obese women. Despite this, the serum levels of parathyroid hormone (PTH), fasting glucose (FG), and alpha-1- acid glycoprotein (A1GPA), total antioxidant capacity (TAC) were similar between groups.

CONCLUSION

In summary, a single oral megadose of VD3 increased 25-hydroxyvitamin D serum levels but did not improve oxidative stress and inflammation markers.

[Vitamin D Deficiency in Sports]

Vitamin D Deficiency in Sports Abstract. A deficiency in vitamin D is very common in the general population as well as in athletes. The aim of this overview is to assess the level of knowledge about the importance of vitamin D for athletes. A deficiency in vitamin D is present in up to 90 % of athletes. Risk groups are young athletes, female athletes, athletes with a limitation such as paraplegia, vegetarians, athletes with a resorption disorder such as celiac disease, athletes training and competing indoors (e.g. ice hockey, basketball, boxing, rhythmic gymnastics), and older athletes. Dark skin pigmentation, the use of sunscreen, the time of day of the training (early morning, late evening) and the geographical location influence the risk for a deficiency in vitamin D. Exposure to the sun and a balanced diet are often not enough to prevent a vitamin D deficiency.

Total, Bioavailable, and Free 25(OH)D Relationship with Indices of Bone Health in Elderly: A Randomized Controlled Trial

CONTEXT

Questions regarding the superiority of free and bioavailable 25-hydroxyvitamin D [25(OH)D] in predicting health outcomes remain unresolved.

OBJECTIVE

This study investigates the impact of vitamin D variables-total, bioavailable, or free 25(OH)D-on indices of bone and mineral metabolism, at baseline and in response to 2 vitamin D doses.

DESIGN

Our objectives are implemented as exploratory analyses on data collected in a 1-year, double-blind, randomized controlled trial completed in July 2014.

SETTING

Participants were recruited from 3 major hospitals in an ambulatory setting.

PARTICIPANTS

Participants were >65 years of age, overweight, and had a baseline serum 25(OH)D between 10 and 30 ng/mL. A total of 221 participants completed the study.

INTERVENTION

Subjects were randomized to receive calcium and oral vitamin D3 (600 IU/day or 3750 IU/day) supplementation.

RESULTS

Participants who received the higher vitamin D dose had levels that were 1.3- to 1.4-fold higher than those taking the lower dose, for all variables (P value < 0.001). Serum values of bioavailable and free 25(OH)D were associated with total 25(OH)D, with r values of 0.942 and 0.943, respectively (P value < 0.001). Parathyroid hormone (PTH) was negatively associated with all vitamin D variables, with correlation coefficients ranging from -0.22 to -0.25, while calcium and bone turnover markers (carboxy-terminal collagen crosslinks and osteocalcin) did not. Only total 25(OH)D had a positive relationship with % change bone mineral density (BMD) at the femoral neck at 12 months, while only free and bioavailable 25(OH) had a positive relationship with % change total body BMD at 12 months.

CONCLUSION

Calculated free and bioavailable 25(OH)D do not appear to be superior to total 25(OH)D in predicting indices of bone health in an elderly population.

A Review of the Relationship of the Cerebrospinal Fluid Changes During the Dysregulation of Parathyroid Hormone With Psychiatric or Neurological Manifestations

It is established that normal calcium and vitamin D concentrations are maintained in the body through parathyroid hormone (PTH), a signaling molecule secreted from parathyroid glands. A massive role is played by PTH in increasing calcium levels when they are extremely low in the body through different mechanisms. The dysregulation of this hormone is due to either over functioning of the gland (hyperparathyroidism) or compromised functioning in hypoparathyroidism. A detailed review was done to identify if any changes are happening in the cerebrospinal fluid (CSF) due to any pathology causing the parathormone to be dysregulated enough to, in turn, cause any further pathology in the nervous system. This may then lead to various disabling neuropsychiatric features. The calcium and vitamin D abnormalities are both directly and indirectly connected to psychiatric features like delusions, schizophrenia, disabled cognition, psychosis, coma, mania, and depression of all kinds.

Moreover, their irregularities are also linked to Alzheimer's. During these manifestations, the CSF is altered concentration-wise, where elevated calcium levels inside are observed during different studies. Despite PTH's indirect connection to the CSF modifications, their association hasn't been potently proven yet, considering more observational studies should be conducted in humans and for a more extended period, along with bigger and greater numbers of CSF samples. Suppose there is a possibility of the link of CSF alterations to PTH. In that case, we can consider a pronounced increase of CSF calcium or PTH as a risk factor for debilitating neuropsychiatric diseases. In this review, the possible correlation of CSF and PTH has been discussed.

The Blockade of TACE-Dependent EGF Receptor Activation by Losartan-Erlotinib Combination Attenuates Renal Fibrosis Formation in 5/6-Nephrectomized Rats Under Vitamin D Deficiency

Chronic kidney disease (CKD) has been considered a major public health issue. In addition to cardiovascular diseases and infections, hypovitaminosis D has been considered a non-traditional aggravating factor for CKD progression. Interstitial fibrosis is a hallmark of CKD strongly correlated with deterioration of renal function. Transforming growth factor β (TGF-β) is the major regulatory profibrotic cytokine in CKD. Many injurious stimuli converge on the TGF-β pathway, which has context-dependent pleiotropic effects and interacts with several related renal fibrosis formation (RFF) pathways. Epidermal growth factor receptor (EGFR) is critically involved in CKD progression, exerting a pathogenic role in RFF associated with TGF-β-related fibrogenesis. Among others, EGFR pathway can be activated by a disintegrin and a metalloproteinase known as tumor necrosis factor α-converting enzyme (TACE). Currently no effective therapy is available to completely arrest RFF and slow the progression of CKD. Therefore, we investigated the effects of a double treatment with losartan potassium (L), an AT1R antagonist, and the tyrosine kinase inhibitor erlotinib (E) on the alternative pathway of RFF related to TACE-dependent EGFR activation in 5/6-nephrectomized rats under vitamin D deficiency (D). During the 90-day protocol, male Wistar rats under D, were submitted to 5/6 nephrectomy (N) on day 30 and randomized into four groups: N+D, no treatment; N+D+L, received losartan (50 mg/kg/day); N+D+E, received erlotinib (6 mg/kg/day); N+D+L+E received losartan+erlotinib treatment. N+D+L+E data demonstrated that the double treatment with losartan+erlotinib not only blocked the TACE-dependent EGF receptor activation but also prevented the expression of TGF-β, protecting against RFF. This renoprotection by losartan+erlotinib was corroborated by a lower expression of ECM proteins and markers of phenotypic alteration as well as a lesser inflammatory cell infiltrate. Although erlotinib alone has been emerging as a renoprotective drug, its association with losartan should be considered as a potential therapeutic strategy on the modulation of RFF.

Calcium daily intake and the efficacy of a training intervention on optimizing calcium supplementation therapy: A clinical audit

BACKGROUND AND AIMS

Calcium is an essential element for human health, with key roles in the prevention and therapy of multifactorial conditions. Calcium dietary intake is often insufficient in the general population. The aim of this study was to perform a clinical audit for general practitioners (GPs) to understand the efficacy of training intervention on doctors' awareness about dietary calcium and supplements.

METHODS AND RESULTS

General practice outpatients were enrolled (Before Clinical Audit, BCA) from the same sanitary district, and calcium dietary intake was evaluated with a validated questionnaire, also collecting information about the consumption of calcium and vitamin D supplements. Then, a training intervention with a frontal lesson and discussion with GPs involved was performed. After one month of this intervention, a second outpatient enrolment was performed (Post Clinical Audit, PCA) in the same general practices to evaluate differences in nutritional suggestions and supplement prescription by GPs. In BCA, the calcium dietary intake was low, with nobody reaching 1000 mg as suggested by the guidelines. Only 6.6% and 24.5% took calcium and vitamin D supplements, respectively; in the PCA, these percentages increased to 28% and 78% for calcium and vitamin D supplements, respectively (p < 0.01 PCA vs BCA). There were no differences in calcium dietary intake between BCA and PCA.

CONCLUSION

Training intervention on GPs was successful to sensitize them regarding calcium intake problems; GPs tended to increase the prescription of supplements but not to suggest changes in dietary habits.

Repeated acute stress modulates hepatic inflammation and markers of macrophage polarisation in the rat

Bidirectional communication between the neuroendocrine stress and immune systems permits classically anti-inflammatory glucocorticoids to exert pro-inflammatory effects in specific cells and tissues. Liver macrophages/Kupffer cells play a crucial role in initiating inflammatory cascades mediated by the release of pro-inflammatory cytokines following tissue injury. However, the effects of repeated acute psychological stress on hepatic inflammatory phenotype and macrophage activation state remains poorly understood. We have utilised a model of repeated acute stress in rodents to observe the changes in hepatic inflammatory phenotype, including anti-inflammatory vitamin D status, in addition to examining markers of classically and alternatively-activated macrophages. Male Wistar rats were subjected to control conditions or 6 h of restraint stress applied for 1 or 3 days (n = 8 per group) after which plasma concentrations of stress hormone, enzymes associated with liver damage, and vitamin D status were examined, in addition to hepatic expression of pro- and anti-inflammatory markers. Stress increased glucocorticoids and active vitamin D levels in addition to expression of glucocorticoid alpha/beta receptor, whilst changes in circulating hepatic enzymes indicated sustained liver damage. A pro-inflammatory response was observed in liver tissues following stress, and inducible nitric oxide synthase being observed within hepatic macrophage/Kupffer cells. Together, this suggests that stress preferentially induces a pro-inflammatory response in the liver.

Poor Status of Vitamin D: A Survey of Area With Lowest Sunlight Radiation in Sichuan, China

OBJECTIVE

Vitamin D plays an important role in bone and mineral metabolism. Ultraviolet B (UVB) is the primary determinant for vitamin D synthesis. However, population-based data of vitamin D status was sparse in areas with sunlight deprivation in China. This study aimed to assess serum 25-hydroxyvitamin D [25(OH)D] levels among adult women in Sichuan basin with the lowest sunlight radiation in China, and the associations with sunlight exposure and age.

METHODS

In the context of the same ethnicity, similar latitude and lifestyle in sunlight-limited basin and sunlight-abundant plateau, 1,057 women in basin and 337 in plateau aged 29-95 years were included in this study, from November 2012 to February 2013. Daily sunlight exposure duration of previous month was obtained using questionnaires. Serum 25(OH)D was measured by enzyme-linked immunosorbent assay.

RESULTS

The prevalence of vitamin D severe deficiency [25(OH)D <30 nmol/L] and deficiency [30 ≤ 25(OH)D <50 nmol/L] was significantly higher in basin than plateau (21.85% vs. 10.09%, and 59.32% vs. 40.36%; P<0.0001). Women from basin exhibited lower serum 25(OH)D levels than those from plateau (40.66 ± 15.62 vs. 52.54 ± 19.94 nmol/L, P<0.0001). In basin, women more than 50 years old had higher 25(OH)D than younger counterparts, and 25(OH)D level of these groups was not associated with sunlight exposure duration. While in plateau, women younger than 60 years old had higher 25(OH)D than the older women. Furthermore, for those younger groups, women with long sunlight exposure (≥3 h daily) had higher 25(OH)D concentration than those with short sunlight exposure (<3 h daily). Serum PTH was negatively associated with 25(OH)D in basin, but not in plateau.

CONCLUSIONS

Alarmingly high prevalence of vitamin D deficiency was observed in women in sunlight-deprived basin in Sichuan. Only the vitamin D status of younger women from plateau with adequate solar radiation could benefit from sunlight exposure. Vitamin D supplementation and vitamin D-fortified food should be encouraged to improve vitamin D status for women living in sunlight-limited areas, or with old age.

Vitamin D pathway-related gene polymorphisms and their association with metabolic diseases: A literature review

PURPOSE

Given that the relationship between vitamin D status and metabolic diseases such as obesity and type 2 diabetes (T2D) remains unclear, this review will focus on the genetic associations, which are less prone to confounding, between vitamin D-related single nucleotide polymorphisms (SNPs) and metabolic diseases.

METHODS

A literature search of relevant articles was performed on PubMed up to December 2019. Those articles that had examined the association of vitamin D-related SNPs with obesity and/or T2D were included. Two reviewers independently evaluated the eligibility for the inclusion criteria and extracted the data. In total, 73 articles were included in this review.

RESULTS

There is a lack of research focusing on the association of vitamin D synthesis-related genes with obesity and T2D; however, the limited available research, although inconsistent, is suggestive of a protective effect on T2D risk. While there are several studies that investigated the vitamin D metabolism-related SNPs, the research focusing on vitamin D activation, catabolism and transport genes is limited. Studies on CYP27B1, CYP24A1 and GC genes demonstrated a lack of association with obesity and T2D in Europeans; however, significant associations with T2D were found in South Asians. VDR gene SNPs have been extensively researched; in particular, the focus has been mainly on BsmI (rs1544410), TaqI (rs731236), ApaI (rs7975232) and FokI (rs2228570) SNPs. Even though the association between VDR SNPs and metabolic diseases remain inconsistent, some positive associations showing potential effects on obesity and T2D in specific ethnic groups were identified.

CONCLUSIONS

Overall, this literature review suggests that ethnic-specific genetic associations are involved. Further research utilizing large studies is necessary to better understand these ethnic-specific genetic associations between vitamin D deficiency and metabolic diseases.

Bone biomarkers in koalas: validation of assays and preliminary analyses

Traumatic injury, including bone fracture, is, to date, one of the leading causes of koala mortality in the South East Queensland region of Australia. Further, the specialist diet of koalas, which is restricted to certain Eucalyptus spp., may impact their normal bone physiology. Considering the dramatic koala population decline and high incidence of trauma, a greater understanding of koala bone physiology may support conservation. We retrieved from GenBank the protein sequences of parathyroid hormone (PTH), osteocalcin (OCN), and tissue-nonspecific alkaline phosphatase (TNALP) in human, dog, cattle, horse, koala, and gray short-tailed opossum. After homology was determined, plasma samples from 13 koalas were analyzed with human PTH, OCN, and bone-specific ALP (BALP) assay kits. Although koala PTH exhibited relatively low sequence homology with placental mammals, high sequence homology between humans and koalas was observed for both OCN and TNALP, and successful cross-reactivity was achieved using human enzyme immunoassay kits for detection of OCN and BALP biomarkers in koala plasma. However, we identified no correlation between OCN and BALP concentrations of healthy and trauma-affected koalas (p = 0.66 and p = 0.79, respectively). Further analysis of OCN and BALP in healthy and diseased koalas will allow a better understanding of bone physiology in this unique marsupial.

The relationship between circulating vitamin D3 and subclinical atherosclerosis in an elderly Asian population

The current evidence regarding the association between vitamin D deficiency and cardiovascular diseases/metabolic disorders is contradictory and inconclusive. In this large-scale observational study, we investigated the relationship between the serum 25-hydroxy vitamin D3 [25(OH)D] concentration and subclinical atherosclerosis in an elderly Asian population. In the I-Lan longitudinal study (ILAS), 1798 elderly, aged 50 and older, were enrolled. For each subject, serum 25-hydroxy vitamin D3 [25(OH)D] concentration and demographic data were recorded. The participants were divided into two groups according to their serum 25(OH)D level (sufficient, > 20 ng/mL and deficient, ≤ 20 ng/mL). Carotid intima-media thickness (cIMT) was measured at bilateral common carotid arteries. Subclinical atherosclerosis was defined as a mean cIMT > 0.81 mm. The mean subject age was 64 ± 9 years old, and 604 (33.6%) were identified as having serum 25(OH)D level ≤ 20 ng/mL. Subjects with serum 25(OH)D level ≤ 20 ng/mL were younger, more likely to be female and smoker, and had a higher incidence of hypertension, dyslipidemia, and metabolic syndrome, compared to those with serum 25(OH)D level > 20 ng/mL. Additionally, patients with serum 25(OH)D level ≤ 20 ng/mL were associated with a lower risk of subclinical atherosclerosis (crude OR: 0.63, 95% CI 0.50–0.81, p < 0.001), according to univariate analysis. However, after adjusting for gender and age, serum 25(OH)D level ≤ 20 ng/mL was not a significant risk factor for subclinical atherosclerosis. Serum 25(OH)D level ≤ 20 ng/mL was not an independent risk factor for subclinical atherosclerosis in this large elderly Asian population. Association observed in the univariate analysis may be confounded by gender or comorbidities.

The Interventional Effects of Tubson-2 Decoction on Ovariectomized Rats as Determined by a Combination of Network Pharmacology and Metabolomics

Post-menopausal osteoporosis (PMOP) is associated with estrogen deficiency and worldwide, is becoming increasingly more prevalent in aging women. Various anti-PMOP drugs have been developed to reduce the burden of PMOP; generally, these drugs are efficacious, but with some adverse side effects. Tubson-2 decoction (TBD), a popular traditional Mongolian medicine, has been used to treat PMOP for centuries. However, the precise mechanisms underlying the action of TBD on PMOP have yet to be fully elucidated. Herein, we combined network pharmacology with untargeted metabolomics to identify the key targets and metabolic pathways associated with the interventional effects of TBD on ovariectomized (OVX) rats. Furthermore, we investigated the bone histomorphometry of eight different groups of rats to evaluate the therapeutic effect of TBD. First, we established a TBD-target/PMOP network via network pharmacology; this network identified three key protein targets-vitamin D receptor (VDR), cytochrome P450 19A1 (CYP19A1), and 11β-hydroxysteroid dehydrogenase type 1 (HSD11B1). Morphological analysis showed that severe impairment of the bone micro-architecture in OVX rats could be improved by TBD administration. The TBD-treated rats had a significantly lower bone surface-to-tissue volume (BS/TV) and a significantly smaller trabecular separation (Tb·Sp.) (P<0.05) than the OVX rats; in contrast, bone volume fraction (BVF), trabecular thickness (Tb·Th.), trabecular number (Tb·N.), and bone mineral density (BMD) were significantly higher in the TBD-treated rats (P<0.05). Multivariate and univariate analysis showed that OVX resulted in significant alterations in the concentrations of 105 metabolites and 11 metabolic pathways (P<0.05); in addition, 26 potential biomarkers were identified to investigate the progression of PMOP. Network pharmacology showed that major alterations in vitamin B6 metabolism were associated with the VDR target. Next, we validated the three crucial targets (VDR [P<0.01], HSD11B1 [P<0.01], and CYP19A1 [P<0.05]) by enzyme-linked immunosorbent assays (ELISAs) and demonstrated that the levels of these targets were elevated in the OVX group but reduced in the TBD-treatment group. Collectively, our results suggest that the interventional effects of TBD on OVX rats are likely to be associated with the down regulation of VDR. Our findings enhance our molecular understanding of the interventional effects of TBD on PMOP and will allow us to develop further TBD studies.

Vitamin D Insufficiency Reduces Grip Strength, Grip Endurance and Increases Frailty in Aged C57Bl/6J Mice

Low 25-OH serum vitamin D (VitD) is pervasive in older adults and linked to functional decline and progression of frailty. We have previously shown that chronic VitD insufficiency in "middle-aged" mice results in impaired anaerobic exercise capacity, decreased lean mass, and increased adiposity. Here, we examine if VitD insufficiency results in similar deficits and greater frailty progression in old-aged (24 to 28 months of age) mice. Similar to what we report in younger mice, older mice exhibit a rapid and sustained response in serum 25-OH VitD levels to differential supplementation, including insufficient (125 IU/kg chow), sufficient (1000 IU/kg chow), and hypersufficient (8000 IU/kg chow) groups. During the 4-month time course, mice were assessed for body composition (DEXA), physical performance, and frailty using a Fried physical phenotype-based assessment tool. The 125 IU mice exhibited worse grip strength (p = 0.002) and inverted grip hang time (p = 0.003) at endpoint and the 8000 IU mice transiently displayed greater rotarod performance after 3 months (p = 0.012), yet other aspects including treadmill performance and gait speed were unaffected. However, 125 and 1000 IU mice exhibited greater frailty compared to baseline (p = 0.001 and p = 0.038, respectively), whereas 8000 IU mice did not (p = 0.341). These data indicate targeting higher serum 25-OH vitamin D levels may attenuate frailty progression during aging.

From Psychiatry to Neurology and Endocrinology: A Case of Hypoparathyroidism

A 31-year-old male patient developed extrapyramidal symptoms while on treatment for depression. He was investigated and found to suffer from hypoparathyroidism. He had calcification in the brain, signs and symptoms of neuromuscular irritability, and QT prolongation on electrocardiogram. He was treated with calcium carbonate and calcitriol. Although he had marked improvement, bradykinesia persisted. This report highlights the importance of maintaining a high index of suspicion for hypocalcemia, and the importance of searching for an organic basis for psychiatric symptoms.

The Molecular Mechanisms by Which Vitamin D Prevents Insulin Resistance and Associated Disorders

Numerous studies have shown that vitamin D deficiency is very common in modern societies and is perceived as an important risk factor in the development of insulin resistance and related diseases such as obesity and type 2 diabetes (T2DM). While it is generally accepted that vitamin D is a regulator of bone homeostasis, its ability to counteract insulin resistance is subject to debate. The goal of this communication is to review the molecular mechanism by which vitamin D reduces insulin resistance and related complications. The university library, PUBMED, and Google Scholar were searched to find relevant studies to be summarized in this review article. Insulin resistance is accompanied by chronic hyperglycaemia and inflammation. Recent studies have shown that vitamin D exhibits indirect antioxidative properties and participates in the maintenance of normal resting ROS level. Appealingly, vitamin D reduces inflammation and regulates Ca²⁺ level in many cell types. Therefore, the beneficial actions of vitamin D include diminished insulin resistance which is observed as an improvement of glucose and lipid metabolism in insulin-sensitive tissues.

Disorders of Calcium and Phosphorus Metabolism and the Proteomics/Metabolomics-Based Research

Since calcium and phosphorus play vital roles in a multitude of physiologic systems, disorders of calcium and phosphorus metabolism always lead to severe consequences such as skeletal-related and cardiovascular morbidity, or even life-threatening. Physiologically, the maintenance of calcium and phosphorus homeostasis is achieved via a variety of concerted actions of hormones such as parathyroid hormone (PTH), vitamin D, and fibroblast growth factor (FGF23), which could be regulated mainly at three organs, the intestine, kidney, and bone. Disruption of any organ or factor might lead to disorders of calcium and phosphorus metabolism. Currently, lacking of accurate diagnostic approaches and unknown molecular basis of pathophysiology will result in patients being unable to receive a precise diagnosis and personalized treatment timely. Therefore, it is urgent to identify early diagnostic biomarkers and develop therapeutic strategies. Fortunately, proteomics and metabolomics offer promising tools to discover novel indicators and further understanding of pathological mechanisms. Therefore, in this review, we will give a systematic introduction on PTH-1,25(OH)₂D-FGF23 axis in the disorders of calcium and phosphorus metabolism, diagnostic biomarkers identified, and potential altered metabolic pathways involved.

Denosumab for cancer-related bone loss

INTRODUCTION

Prolonged use of anti-cancer treatments in breast and prostate tumors alters physiological bone turnover leading to adverse skeletal related events, such as osteoporosis, loss of bone mass, and increased risk of fractures. These complications known as cancer treatment-induced bone loss (CTIBL) should be managed with bone targeting agents such as the bisphosphonates and denosumab. The latter is a monoclonal antibody against the receptor activator of nuclear factor-kB ligand (RANKL) that suppresses osteoclasts function and survival increasing bone mass.

AREAS COVERED

This review will focus on the mechanisms associated with bone loss induced by cancer treatments and the most recent evidence about the use of denosumab as preventive and therapeutic strategy to protect bone health. Moreover, we will discuss several key aspects regarding the clinical practical use of denosumab to optimize the management of CTLIB in breast and prostate cancer.

EXPERT OPINION

Denosumab treatment strongly prevents cancer therapies-related skeletal issues in breast and prostate cancer with a good safety profile. Adjuvant six-monthly denosumab delays the time to first fracture onset in early stage breast cancer patients with normal or altered bone mineral density (BMD). Similarly, denosumab treatment is able to prevent fractures and BMD loss in nonmetastatic prostate cancer patients.

THE VITAMIN D STATUS OF ASIAN ELEPHANTS (ELEPHAS MAXIMUS) MANAGED IN A NORTHERN TEMPERATE CLIMATE

Knowledge about the normal metabolism and involvement of vitamin D in elephant calcium homeostasis is essential to understanding the possible role of vitamin D in Asian elephant (Elephas maximus) health, as well as to informing accurate diet formulation. This study provides an evaluation of analytes involved in vitamin D metabolism, in conjunction with dietary intake and ultraviolet light (UV) exposure, in Asian elephants managed in a northern temperate climate. Once monthly, for a total of 12 mo, serum from six adult Asian elephants was analyzed for 25-hydroxyvitamin D [25(OH)D], 24,25-dihydroxyvitamin D [24,25(OH)₂D], 1,25-dihydroxyvitamin D [1,25(OH)₂D], parathyroid hormone (PTH), total calcium (Ca), ionized calcium (iCa), phosphorus (P), and magnesium (Mg). The diet was analyzed monthly for vitamin D, Ca, and P. Monthly average vitamin D-weighted UV daily sums were determined to gauge average UV light exposure within the vitamin D action spectrum. No serum or diet parameters were affected by time or season. Average serum 25(OH)D₂ was 7.02 ± 0.85 ng/ml. 25(OH)D₃ levels were nondetectable in all samples despite supplementation of the diet with recommended levels of vitamin D₃, and UV exposure was at sufficient levels for cutaneous vitamin D synthesis for 6 mo of the year. Levels of 24,25(OH)₂D averaged 31.7% higher than 25(OH)D, and average 1,25(OH)₂D₂ was 11.24 ± 1.04 pg/ml. Values for PTH, Ca, iCa, P, and Mg were within expected ranges for Asian elephants. The information gained from this research expands the knowledge base for these analytes, evaluates 24,25-dihydroxyvitamin D for the first time, and provides new information regarding vitamin D metabolism and test interpretation in the Asian elephant.

Clinical Severity and Calcium Metabolism in Patients with Bipolar Disorder

Parathyroid hormone (PTH), vitamin D and serum calcium play a key role in several physiological and pathological conditions. Vitamin D and PTH receptors are largely expressed in the central nervous system and are involved in the modulation of inflammatory responses. Few studies investigated the association between calcium homeostasis imbalance and psychiatric disorders. This study aims to assess calcium homeostasis imbalance in patients with bipolar disorder (BD) and its impact on clinical outcome. We recruited 199 patients with BD, who were administered with validated assessment instruments to investigate depressive, manic and anxiety symptoms, affective temperaments, childhood trauma and global functioning. Serum calcium, vitamin D and PTH levels were assessed in all patients. Levels of PTH correlated with several clinical characteristics, including the diagnosis of bipolar disorder type I (BD-I), the presence of psychotic symptoms, lithium treatment, suicidality, total number of acute episodes and of hospitalizations (p < 0.0001) and seasonality (p < 0.05). At the regression analyses, higher levels of PTH were predicted by early age at onset, number of hospitalizations, aggressive behaviors (p < 0.05), higher Childhood Trauma Questionnaire total score (CTQ) (p < 0.001) and treatment with lithium (p = 0.01). Our findings suggest that the calcium homeostasis could play a role in BD patients, and that PTH levels are correlated with the clinical severity of the disorder.

Development of Algorithm for Clinical Management of Sickle Cell Bone Disease: Evidence for a Role of Vertebral Fractures in Patient Follow-up

Sickle-cell disease (SCD) is a worldwide distributed hemoglobinopathy, characterized by hemolytic anemia associated with vaso-occlusive events. These result in acute and chronic multiorgan damage. Bone is early involved, leading to long-term disability, chronic pain and fractures. Here, we carried out a retrospective study to evaluate sickle bone disease (SBD) in a cohort of adults with SCD. We assessed bone density, metabolism and turnover. We also evaluated the presence of fractures and the correlation between SCD severity and skeletal manifestations. A total of 71 patients with SCD were analyzed. The mean age of population was 39 ± 10 years, 56% of which were females. We found osteoporosis in a range between 7% and 18% with a high incidence of vertebral fractures. LDH and AST were predictive for the severity of vertebral fractures, while bone density was not. Noteworthy, we identified -1.4 Standard Deviations T-score as the cutoff for detecting the presence of fractures in patients with SCD. Collectively our data allowed us to develop an algorithm for the management of SBD, which may be useful in daily clinical practice to early intersect and treat SBD.

Poor dietary consumption and limited sun exposure are risk factors for vitamin D deficiency in premenopausal Kuwaiti women: A cross-sectional study

Background: Low serum vitamin D levels are reported constantly among females living in the Arabian Gulf countries, presumably due to their lifestyle, which limits direct sun exposure. Because Vitamin D deficiency has been implicated in a wide range of ailments, healthy females with the deficiency might be at risk for developing many health problems. Thus, the aim was to assess lifestyle risk factors for vitamin D deficiency in healthy women in Kuwait. Methods: A total of 104, disease-free, premenopausal women were recruited for assessment of their serum 25OHD and intact PTH levels. Physical examination, blood withdrawal and interviewer-administered questionnaires were used to collect the relevant data. Associations were detected statistically using nonparametric tests and logistic regression was used to identify risk factors for vitamin D deficiency. Results: Vitamin D deficiency ( < 25 nmol/L) occurred in 84.6%, and hyperparathyroidism ( ≥ 6.9 pmol/L) occurred in 25% of women, among which all were vitamin D deficient. Significant risk factors of vitamin D deficiency were nondaily milk intake (OR:25, CI%:4.2-147), no fish intake (OR:5, CI%:1-22.8), and no weekend sun exposure (OR:8.2, CI%:1.28-52.6). Having PTH ≥ 6 pmol/L was also associated with a higher likelihood of having vitamin D deficiency. Conclusion: Vitamin D deficiency is very common in disease-free, premenopausal Kuwaiti women and can be avoided by improving food consumption and obtaining more sun exposure.

Phosphate Transport in Epithelial and Nonepithelial Tissue

Phosphate is an essential nutrient for life and is a critical component of bone formation, a major signaling molecule, and structural component of cell walls. Phosphate is also a component of high-energy compounds (i.e., AMP, ADP, and ATP) and essential for nucleic acid helical structure (i.e., RNA and DNA). Phosphate plays a central role in the process of mineralization, normal serum levels being associated with appropriate bone mineralization, while high and low serum levels are associated with soft tissue calcification. The serum concentration of phosphate and the total body content of phosphate are highly regulated, a process that is accomplished by the coordinated effort of two families of sodium-dependent transporter proteins. The three isoforms of the SLC34 family (SLC34A1-A3) show very restricted tissue expression and regulate intestinal absorption and renal excretion of phosphate. SLC34A2 also regulates the phosphate concentration in multiple lumen fluids including milk, saliva, pancreatic fluid, and surfactant. Both isoforms of the SLC20 family exhibit ubiquitous expression (with some variation as to which one or both are expressed), are regulated by ambient phosphate, and likely serve the phosphate needs of the individual cell. These proteins exhibit similarities to phosphate transporters in nonmammalian organisms. The proteins are nonredundant as mutations in each yield unique clinical presentations. Further research is essential to understand the function, regulation, and coordination of the various phosphate transporters, both the ones described in this review and the phosphate transporters involved in intracellular transport.

Protective Role of Vitamin D in Renal Tubulopathies

Vitamin D is tightly linked with renal tubular homeostasis: the mitochondria of proximal convoluted tubule cells are the production site of 1α,25-dihydroxyvitamin D3. Patients with renal impairment or tubular injury often suffer from chronic inflammation. This alteration comes from oxidative stress, acidosis, decreased clearance of inflammatory cytokines and stimulation of inflammatory factors. The challenge is to find the right formula for each patient to correctly modulate the landscape of treatment and preserve the essential functions of the organism without perturbating its homeostasis. The complexity of the counter-regulation mechanisms and the different axis involved in the Vitamin D equilibrium pose a major issue on Vitamin D as a potential effective anti-inflammatory drug. The therapeutic use of this compound should be able to inhibit the development of inflammation without interfering with normal homeostasis. Megalin-Cubilin-Amnionless and the FGF23-Klotho axis represent two Vitamin D-linked mechanisms that could modulate and ameliorate the damage response at the renal tubular level, balancing Vitamin D therapy with an effect potent enough to contrast the inflammatory cascades, but which avoids potential severe side effects.

Children and adolescents with obesity have reduced serum bone turnover markers and 25-hydroxyvitamin D but increased parathyroid hormone concentrations - Results derived from new pediatric reference ranges

BACKGROUND

We aimed to establish age- and gender-specific reference ranges for concentrations of the bone markers osteocalcin (OC), procollagen type 1 N-propeptides (PINP) and carboxy-terminal cross-linking telopeptide of type 1 collagen (CTX-I) as well as for the calciotropic hormones 25-hydroxyvitamin D [25(OH)D] and parathyroid hormone (PTH) in healthy infants, children and adolescents. In addition, the effect of age, gender, puberty and body mass index (BMI) on bone markers was investigated.

METHODS

2416 healthy subjects (5714 blood withdrawals), aged 3 months to 17 years, were included to estimate the age- and gender-dependence of reference ranges. Subsequently, measured values of the biomarkers were transformed to standard deviation scores (SDS) and their associations with age, gender and puberty were analyzed. Bone marker-SDS values of the reference cohort were compared with an obese cohort (n = 317 and 489 blood withdrawals) to analyze the effect of BMI.

RESULTS

OC, PINP and CTX-I showed a distinct age- and gender-dependence with peak levels at 10 to 11 years (girls, Tanner 3) and 13 years (boys, Tanner 3-4). Children with obesity had significantly lower SDS levels for OC (-0.44), PINP (-0.27), CTX-I (-0.33), 25(OH)D (-0.43) and higher SDS levels for PTH (+0.44) than the reference cohort.

CONCLUSIONS

OC, PINP and CTX-I vary with age, gender and pubertal stage. The body weight status has to be considered in the interpretation of pediatric OC, PINP, CTX-I, 25(OH)D and PTH levels. Consequences of childhood obesity on bone health should be carefully investigated in long-term studies.

PTH: Redefining Reference Ranges in a Healthy Population-The Role of Interfering Factors and the Type of Laboratory Assay

Introduction. Parathyroid hormone (PTH) is a linear peptide constituted by 84 amino acids and active in its 1-84 form, but a wide range of PTH forms produced by its post-transcriptional modifications are present in blood. Many assays with different specificities are commercially available. The aim of our study was to compare a 2^nd and 3^rd generation in healthy population in order to better define the reference range in the healthy population residing in our region. Materials and Methods. 108 subjects (53 females and 55 males) referring to the transfusion donor were enrolled in the study centre in April 2016 and underwent PTH levels measurements with a 3^rd generation kit (chemiluminescent immunoassay DiaSorin Liaison) and with a 2^nd generation kit (immunoradiometric assay Total Intact PTH Assay (Coated Tube), Scantibodies). Also calcium, phosphate, creatinine, and 25OHD3 were measured. A questionnaire on lifestyle and dietary habits was obtained.

RESULTS

The median PTH values obtained with the 2^nd generation assay and the whole 3^rd generation assay were 20.26 pg/ml and 23.11 pg/ml, respectively. Bland-Altman method showed substantial concordance between the two PTH assays, although with an overestimation of the 3^rd generation method over the 2^nd generation method. There was no correlation between 3^rd generation PTH and 25OHD3 and creatinine. Calcium was negatively correlated with PTH only when measured with 3^rd generation kit.

CONCLUSIONS

On the basis of our data, obtained from healthy subjects, we can conclude that the reference range used by our laboratory was too narrow and was necessary to reestablish normal ranges according to our population. This is useful to avoid hyperparathyroidism misdiagnosis.

Paradoxical Response of Parathyroid Hormone to Vitamin D-Calcium Supplementation in Indian Children

OBJECTIVES

To investigate the effect of oral vitamin D-calcium supplementation on serum intact parathyroid hormone (PTH), calcium, phosphorous, and alkaline phosphatase (ALK-P) concentrations in children with habitually low calcium intakes.

STUDY DESIGN

In this follow-up study to a randomized controlled trial that aimed to assess the effect of vitamin D-calcium supplementation on immunity, data related to dietary intake, anthropometry, and biochemistry [serum 25(OH)D and bone profile] were collected from 178 children-79 in the vitamin D group and 99 in the non-vitamin D group.

RESULTS

Dietary calcium to phosphorus intake ratio was 0.4:1. Baseline serum 25(OH)D concentration was 58.2 ± 10.9 nmol/L; 66% children were vitamin D sufficient and none deficient. After supplementation, vitamin D group, compared with the non-vitamin D group, had significantly (P < .05) greater 25(OH)D (83.9 ± 30.1 nmol/L vs 58.3 ± 15.7 nmol/L), significantly greater PTH (6.7 ± 3.6 pmol/L vs 5.5 ± 3.2 pmol/L), and positive correlation (r_s = 0.24) between serum 25(OH)D and PTH (vs negative correlation [r_s = -0.1] in non-vitamin D group). Mean concentrations of serum bone measures in the vitamin D group were calcium (2.2 ± 0.1 mmol/L), phosphorus (1.7 ± 0.2 mmol/L), and ALK-P (178.7 ± 40.7 IU/L). At follow-up, 1-year post-supplementation, in the vitamin D group, PTH concentrations continued to remain high (but not significantly different from levels at 6 months), with low normal serum calcium, high normal phosphate, and ALK-P in reference range.

CONCLUSIONS

In children who are vitamin D sufficient but with habitually low dietary calcium intake, vitamin D-calcium supplementation paradoxically and significantly increased serum PTH concentrations with no apparent effect on other bone biochemistry. Chronic low dietary calcium to phosphorus ratio is likely to have caused this paradoxical response.

The role of nutrition and physical activity in frailty: A review

Frailty is a clinical syndrome with a worldwide prevalence of 5-27% among those aged over 65 years. Frailty is characterised by loss of muscle strength and impaired physical function, and is associated with increased falls, hospitalisation and death. Nutritional deficiencies and low physical activity are common in this age group due to ill health, disability and reductions in enthusiasm, food intake and therefore, energy availability. Both low physical activity and inadequate dietary intake have a significant role to play in the onset and progression of frailty, primarily through bone and muscle health implications. Frailty is, however, preventable and reversible, and several interventions have been carried out to offset and reverse the condition. This article reports the recent evidence on the role of nutrition and physical activity in the pathogenesis of frailty and provides a critical review of previously implemented interventions focussed on physical activity and nutrition to prevent and reduce frailty among older adults.

Associations between Vitamin D and Liver Function and Liver Fibrosis in Patients with Biliary Atresia

Objectives

To detail the effects of vitamin D (VD) deficiency and assess the relationships between VD deficiency and liver function and liver fibrosis in patients with biliary atresia (BA).

Methods

In this study, BA patients confirmed by intraoperative cholangiography were enrolled between January 2017 and February 2019. Preoperative serum 25-(OH)D level, liver function, serum biomarker levels of liver fibrosis, and histopathologic features were recorded. Deficiency, insufficiency, and sufficiency of VD were defined as serum 25-(OH)D concentrations of <10, 10-20, and >20 ng/ml, respectively. Associations between serum 25-(OH)D level and liver function and liver fibrosis were analyzed.

Results

A total of 161 BA infants were included. The median (interquartile range (IQR)) serum 25-(OH)D level in all patients was 7.56 (IQR: 4.48–11.40) ng/ml. The rates of 25-(OH)D deficiency, insufficiency, and sufficiency were 67.1% (108/161), 29.2% (47/161), and 3.7% (6/161), respectively. Serum 25-(OH)D level was negatively correlated with alkaline phosphatase (r = ‐0.232, P = 0.003). After adjusting for age, a decrease in serum 25-(OH)D level was correlated with the increase of the Batts-Ludwig stage score (odds ratio (OR): 0.94, 95% confidence interval (CI): 0.88–0.99; P = 0.028). Serum 25-(OH)D level was also correlated with the N-terminal propeptide of type III procollagen (PIIINP) (r = ‐0.246, P = 0.002). Additionally, PIIINP (P = 0.038) and ALP (P = 0.031) were independently associated with serum 25-(OH)D level.

Conclusions

VD deficiency was common and inversely correlated with liver fibrosis in BA patients. Furthermore, VD was not correlated with liver function except alkaline phosphatase.

Parathyroid hormone reference ranges in healthy individuals classified by vitamin D status

PURPOSE

Parathyroid hormone (PTH) concentrations are routinely measured in the diagnosis and management of bone and kidney diseases, but reference ranges can be overestimated if determined in otherwise healthy individuals for whom vitamin D deficiency was not evaluated. We establish PTH reference ranges in apparently healthy, normocalcemic, normophosphatemic individuals categorized by 25-hydroxyvitamin D (25(OH)D) status using the Elecsys^® PTH (cobas e 601) and Elecsys^® Vitamin D total II electrochemiluminescence immunoassays (cobas e 411).

METHODS

This prospective, non-interventional study measured PTH in serum from 653 apparently healthy adults [56.7% female; 68.2% white/Caucasian; 28.6% African American; median age 44 years (range 21-83)] from three diverse geographic sites across the USA during summer and winter months. Subjects were classified by concomitant vitamin D sufficiency (≥ 30 ng/mL), insufficiency (> 20 to < 30 ng/mL) or deficiency (≤ 20 ng/mL).

RESULTS

In vitamin D sufficiency, median PTH was 31.9 pg/mL [range (2.5th-97.5th percentile) 17.9-58.6] compared with 35.5 pg/mL (17.0-60.4) for insufficiency, and 39.8 pg/mL (19.5-86.4) for deficiency. A significant inverse relationship was found between PTH and 25(OH)D (P < 0.001). After accounting for vitamin D, potential effects of race or season as covariates were relatively small or absent.

CONCLUSIONS

Upper reference limits (URL) for PTH in vitamin D sufficiency/insufficiency were similar and lower than current values. Clinically important PTH elevations were observed in vitamin D deficiency, where revised reference ranges with a higher URL may be appropriate. These data may help to distinguish vitamin D-related PTH elevations from other causes [e.g., primary (normocalcemic) or secondary hyperparathyroidism].

Systematic Pharmacological Methodology to Explore the Pharmacological Mechanism of Siwu Decoction for Osteoporosis

Osteoporosis is an important health problem worldwide. Siwu decoction (SWD) and its modification have a good clinical effect on osteoporosis. However, the molecular mechanism of SWD on osteoporosis has not been thoroughly explained. A systematic pharmacological methodology was utilized to predict the active compounds and potential targets of SWD, collect the genes of osteoporosis and the known targets of SWD, and analyze the osteoporosis and SWD's network. Five networks were constructed and analyzed: (1) Osteoporosis genes' protein-protein interaction (PPI) network; (2) Compound-compound target network of SWD; (3) SWD-osteoporosis PPI network; (4) Compound-known target network of SWD; and (5) SWD known target- osteoporosis PPI network. Several osteoporosis and treatment-related targets (eg.,. HSP90AB1, FGFR1, HRAS, GRB2, and PGF), clusters, biological processes, and signaling pathways (e.g., PI3K-Akt signaling pathway, insulin signaling pathway, MAPK signaling pathway and FoxO signaling pathway) were found. The therapeutic effect of SWD on osteoporosis may be achieved by interfering with the biological processes and signaling pathways related to the development of osteoporosis.

Emerging Role of Vitamin D and its Associated Molecules in Pathways Related to Pathogenesis of Thrombosis

Vitamin D, besides having an essential role in calcium and bone metabolism, also acts as a mediator of many non-calcemic effects through modulations of several biological responses. Vitamin D exists in its two major forms, vitamin D₂, or commonly known as ergocalciferol, and vitamin D₃, or commonly known as cholecalciferol. Both of these forms bind to vitamin D-binding protein to get transported to all vital target organs, where it serves as a natural ligand to vitamin D receptors for enabling their biological actions. Clinical reports corroborating vitamin D deficiency with an increase in thrombotic episodes implicate the role of vitamin D and its associated molecule in the regulation of thrombosis-related pathways. Thrombosis is the formation and propagation of a blood clot, known as thrombus. It can occur either in the arterial or the venous system resulting in many severe complications, including myocardial infarction, stroke, ischemia, and venous thromboembolism. Vitamin D, directly or indirectly, controls the expression of several genes responsible for the regulation of cellular proliferation, differentiation, apoptosis, and angiogenesis. All of these are the processes of potential relevance to thrombotic disorders. This review, thus, discussed the effects of vitamin D on pathways involved in thrombosis, such as hemostatic process, inflammatory pathway, and endothelial cell activation, with a focus on the molecular mechanisms associated with them.

Circulating levels of free 25(OH)D increase at the onset of rheumatoid arthritis

OBJECTIVE

Epidemiological studies suggest vitamin D deficiency as a potential risk factor for rheumatoid arthritis (RA) development, a chronic autoimmune disorder highly prevalent in indigenous North American (INA) population. We therefore profiled the circulating levels of 25-hydroxyvitaminD [25(OH)D], an active metabolite of vitamin D, in a cohort of at-risk first-degree relatives (FDR) of INA RA patients, a subset of whom subsequently developed RA (progressors).

METHODS

2007 onward, serum samples from INA RA patients and FDR were collected at the time of a structured baseline visit and stored at -20°C. Anti-citrullinated protein antibodies (ACPA), 25(OH)D, hs-CRP, vitamin-D binding protein (VDBP) and parathyroid hormone (PTH) levels were determined using ELISA and rheumatoid factor (RF) seropositivity was determined by nephelometry.

RESULTS

We demonstrate that 25 (OH) D concentrations were lower in winter than summer (P = 0.0538), and that serum 25(OH)D levels were higher in samples collected and stored after 2013 (P<0.0001). Analysis of samples obtained after 2013 demonstrated that 37.6% of study participants were 25(OH)D insufficient (<75nmol/L). Also, seropositive RA patients and FDR had lower 25(OH)D levels compared to ACPA-/FDR (P<0.05, P<0.01 respectively). Linear regression analysis showed 25(OH)D insufficiency was inversely associated with presence of RA autoantibodies. Longitudinal samples from 14 progressors demonstrated a consistent increase in 25(OH)D levels at the time they exhibited clinically detectable joint inflammation, without any significant change in VDBP or PTH levels. Spearman rank correlation analysis showed significant association between 25(OH)D and PTH levels, both in RA patients and progressors at RA onset time.

CONCLUSION

We demonstrate that 25(OH)D levels in serum increased at RA onset in progressors. The potential role that vitamin D metabolites and their downstream effects play in RA transition requires further investigation.

The Effect of Calcium Deficiency on Bone Properties in Growing Rats

Background:

In this work, the study of the physicochemical properties of the rat bones that were fed under severe and moderate calcium depletion was carried out. Calcium depletion is a common problem in the diet of the third world.

Objective:

Three calcium levels: 5000, 2500, and 1039 mg/kg, were used in the diets to evaluate the influence of calcium deficiency on the bone quality by post-mortem tests.

Methods:

Inductive Coupled Plasma was used to study the elemental chemical composition of the bones; X-ray diffraction evaluated the bone structure and crystallinity; the microstructure and architecture were investigated using scanning electron microscopy; thermogravimetric analysis assessed the ratio between organic and inorganic phases of bones. All of these results were correlated with flexion and compression test determining the biomechanical properties to evaluate the bone quality.

Results:

The results showed that severe calcium depletion (75% depletion, 1039 mg/kg) was a critical factor in the unsuitable mineralization process responsible for the deterioration of bone quality. Bone architecture with delicate trabeculae caused the poor mechanical response. For moderate calcium depletion (50% of the request, 2500 mg/kg), the bone quality and its mechanical behavior showed less deterioration in comparison with bones of severe calcium depletion diet.

Conclusion:

By using this animal model, the effect of calcium depletion in bone mineralization in rats was understood and can be extrapolated for humans.

Association between serum vitamin B6 concentration and risk of osteoporosis in the middle-aged and older people in China: a cross-sectional study

OBJECTIVE

To determine the relationship between serum vitamin B₆ (Vit B₆) concentration and the status of bone mineral density and identify the relationship between serum Vit B6 and bone metabolism parameters in middle-aged and older people in China.

DESIGN

The present study was a cross-sectional study within the framework of an ongoing prospective population-based cohort study.

SETTING AND PARTICIPANTS

A total of 1829 residents (men ≥50 years and women ≥45 years) from two subdistricts were recruited from July 2015 to February 2016 in Shanghai, China.

MEASURES

Recruited residents were grouped (control, osteopenia and osteoporosis) according to their lumbar spine bone mineral density, measured through dual-energy X-ray absorptiometry. Serum Vit B₆ concentrations, bone turnover marker concentrations and calcium and phosphorus metabolism parameters were assessed.

RESULTS

No significant linear trend between serum Vit B₆ concentrations and lumbar bone mass was observed in the men. In the women, the average osteoporosis risk was 61% higher at serum Vit B₆ concentrations of <19.2 μg/L than at those of >26.9 μg/L (OR 1.61, 95% CI 1.00 to 2.58). However, there was no significance after controlling of serum 25-hydroxy-vitamin D concentration and parathyroid hormone concentration, respectively. In the osteoporotic women, the serum Vit B₆ concentration was significantly negatively correlated to concentrations of bone turnover marker including N-terminal propeptide of type I collagen, β-C-terminal telopeptide of type I collagen and osteocalcin. It was also positively related to the serum 25-hydroxy-vitamin D concentration and inversely related to the serum parathyroid hormone concentration.

CONCLUSIONS

A relatively low serum Vit B₆ concentration, even in the normal range, may be a risk factor for osteoporosis in postmenopausal women, which is dependent on serum 25-hydroxy-vitamin D concentration and parathyroid hormone concentration.

TRIAL REGISTRATION NUMBER

NCT02958020; Post-results.

Role of Vitamin D Status in Diabetic Patients with Renal Disease

Diabetes mellitus (DM) poses a major public health problem worldwide, with ever-increasing incidence and prevalence in recent years. The Institute for Alternative Futures (IAF) expects that the total number of people with type 1 and type 2 DM in the United States will increase by 54%, from 19,629,000 to 54,913,000 people, between 2015 and 2030. Diabetic Nephropathy (DN) affects about one-third of patients with DM and currently ranks as the first cause of end-stage kidney disease in the Western world. The complexity of interactions of Vitamin D is directly related with progressive long-term changes implicated in the worsening of renal function. These changes result in a dysregulation of the vitamin D-dependent pathways. Various studies demonstrated a pivotal role of Vitamin D supplementation in regression of albuminuria and glomerulosclerosis, contrasting the increase of glomerular basement membrane thickening and podocyte effacement, with better renal and cardiovascular outcomes. The homeostasis and regulation of the nephron’s function are absolutely dependent from the cross-talk between endothelium and podocytes. Even if growing evidence proves that vitamin D may have antiproteinuric, anti-inflammatory and renoprotective effects in patients with DN, it is still worth investigating these aspects with both more in vitro studies and randomized controlled trials in larger patient series and with adequate follow-up to confirm the effects of long-term vitamin D analogue supplementation in DN and to evaluate the effectiveness of this therapy and the appropriate dosage.

Physical & mental activities enhance the neuroprotective effect of vinpocetine & coenzyme Q10 combination against Alzheimer & bone remodeling in rats

BACKGROUND

Alzheimer's disease is a neurodegenerative disorder characterized by a progressive decline of cognitive abilities as well as bone loss. Physical and mental activities maintain cognitive functions as well as increase bone mass by inhibiting bone resorption. VIN and CoQ10 are neuroprotective drugs that possess anti-inflammatory and antioxidant properties.

AIMS

To study the effect of PH&M on enhancing the neuroprotective role of VIN and CoQ10 combination during induction of AD model in rats besides their role against bone mass loss associated with AD model.

MAIN METHODS

Six groups of rats were received saline, AlCl₃, and PH&M daily either alone or with a combination of VIN and CoQ10 for 4 weeks. Various biochemical analyses were performed to evaluate the extent of brain damage such as ACHE, β-secretase, chitinase, Aβ, tau protein, and monoamines besides the inflammatory and antioxidant parameters. Serum levels of minerals as well as 25-OHD, PTH, RANKL, and OPG levels were measured to detect the extent of bone impairment. Also, histopathological changes were evaluated in different brain regions and hind paw.

KEY FINDINGS

VIN and CoQ10 combination together with PH&M significantly attenuated the neurodegeneration induced by AlCl₃ administration through the improvement of AD markers in brain tissue as well as oxidant and inflammatory markers. Bone resorption markers, serum minerals, and PTH levels were also normalized too.

SIGNIFICANCE

Neuroprotective drugs together with PH&M have a more protective effect against AD and bone loss rather than PH&M alone.

Activation of the calcium sensing receptor attenuates TRPV6-dependent intestinal calcium absorption

Plasma calcium (Ca2+) is maintained by amending the release of parathyroid hormone and through direct effects of the Ca2+ sensing receptor (CaSR) in the renal tubule. Combined, these mechanisms alter intestinal Ca2+ absorption by modulating 1,25-dihydroxy vitamin D3 production, bone resorption, and renal Ca2+ excretion. The CaSR is a therapeutic target in the treatment of secondary hyperparathyroidism and hypocalcemia a common complication of calcimimetic therapy. The CaSR is also expressed in intestinal epithelium, however, a direct role in regulating local intestinal Ca2+ absorption is unknown. Chronic CaSR activation decreased expression of genes involved in Ca2+ absorption. In Ussing chambers, increasing extracellular Ca2+ or basolateral application of the calcimimetic cinacalcet decreased net Ca2+ absorption across intestinal preparations acutely. Conversely, Ca2+ absorption increased with decreasing extracellular Ca2+ concentration. These responses were absent in mice expressing a non-functional TRPV6, TRPV6D541A. Cinacalcet also attenuated Ca2+ fluxes through TRPV6 in Xenopus oocytes when co-expressed with the CaSR. Moreover, the phospholipase C inhibitor, U73122, prevented cinacalcet-mediated inhibition of Ca2+ flux. These results reveal a regulatory pathway whereby activation of the CaSR in the basolateral membrane of the intestine directly attenuates local Ca2+ absorption via TRPV6 to prevent hypercalcemia and help explain how calcimimetics induce hypocalcemia.

Vitamin D and growth hormone in children: a review of the current scientific knowledge

Background

Human growth is a complex mechanism that depends on genetic, environmental, nutritional and hormonal factors. The main hormone involved in growth at each stage of development is growth hormone (GH) and its mediator, insulin-like growth factor 1 (IGF-1). In contrast, vitamin D is involved in the processes of bone growth and mineralization through the regulation of calcium and phosphorus metabolism. Nevertheless, no scientific study has yet elucidated how they interact with one another, especially as a dysfunction in which one influences the other, even if numerous biochemical and clinical studies confirm the presence of a close relationship.

Main body

We reviewed and analyzed the clinical studies that have considered the relationship between vitamin D and the GH/IGF-1 axis in pediatric populations. We found two main areas of interest: the vitamin D deficiency status in patients affected by GH deficit (GHD) and the relationship between serum vitamin D metabolites and IGF-1. Although limited by some bias, from the analysis of the studies presented in the scientific literature, it is possible to hypothesize a greater frequency of hypovitaminosis D in the subjects affected by GHD, a reduced possibility of its correction with only substitution treatment with recombinant growth hormone (rGH) and an improvement of IGF-1 levels after supplementation treatment with vitamin D.

Conclusions

These results could be followed by preventive interventions aimed at reducing the vitamin D deficit in pediatric age. In addition, further research is needed to fully understand how vitamin D and growth are intertwined.

Effect of 16-weeks vitamin D replacement on calcium-phosphate homeostasis in overweight and obese adults

This randomised placebo-controlled trial aimed to determine the effect of 16-weeks cholecalciferol supplementation on calcium-phosphate homeostasis and bone mineral density (BMD) in overweight and obese adults. Fifty-four vitamin D-deficient (25OHD<50 nmol/L), overweight and obese adults (mean age 32 ± 8.5 years) were included in the trial. Participants were randomly assigned to receive either a bolus oral dose of 100,000 IU cholecalciferol followed by 4000 IU cholecalciferol/d or a matching placebo for 16 weeks. Before and after the intervention, serum calcium, phosphate, 25-hydroxyvitamin D [25(OH)D], intact parathyroid hormone (iPTH) and C-terminal plasma fibroblast growth factor-23 (cFGF-23) concentrations were measured. Whole-body BMD was assessed using dual-energy X-ray absorptiometry (DXA) and diet and sun exposure were assessed using self-administered questionnaires. There were no significant differences in baseline characteristics between the vitamin D and placebo group. After 16-weeks of vitamin D supplementation, mean changes in 25(OH)D concentration were higher in the vitamin D group (57 nmol/L 95% CI 49, 65) compared with placebo (2 nmol/L 95% CI -4, 8), P < 0.001. Additionally, iPTH concentrations declined in the vitamin D group (-1.19 pmol/L 95% CI -1.9, -0.47) compared with placebo (0.14 pmol/L 95% CI -0.49, 0.77), P = 0.006. There were no significant differences in calcium, phosphate, iPTH and cFGF-23 concentrations and whole-body BMD between vitamin D and placebo at follow-up. Inverse correlations were observed between mean change in serum iPTH and cFGF-23 in the vitamin D group only (r=-0.41, P = 0.029). In individuals with greater vitamin D deficiency at baseline (25(OH)D < 30 nmol/L), there was a significant increase in mean whole-body BMD (0.01 g/cm², 95% CI 0.001, 0.025) however, the mean change in BMD was not different between vitamin D and placebo groups in this sub-group analysis. We conclude that cholecalciferol supplementation for 16 weeks increases serum 25(OH)D concentrations and reduces iPTH concentrations in overweight and obese, but otherwise healthy adults with vitamin D deficiency, and has no effect on calcium, phosphate and iFGF-23 concentrations and whole-body BMD.