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Osteoporosis International : a Journal... Jun 2024Skeletal fluorosis (SF) results from chronic exposure to fluoride (F-) causing excessive aberrantly mineralized brittle bone tissue, fractures, and exostoses. There is...
PURPOSE
Skeletal fluorosis (SF) results from chronic exposure to fluoride (F-) causing excessive aberrantly mineralized brittle bone tissue, fractures, and exostoses. There is no established treatment other than avoiding the source of F-. Still, excess F- can persist in bone for decades after exposure ceases.
CASE PRESENTATION
A 50-year-old woman presented with multiple, recurrent, low AQ2 trauma fractures yet high radiologic bone mineral density. Serum F- was elevated, and osteomalacia was documented by non-decalcified transiliac biopsy. She reported intermittently "huffing" a keyboard cleaner containing F- (difluoroethane) for years. Following cessation of her F- exposure, we evaluated the administration of the parathyroid hormone analog, abaloparatide, hoping to increase bone remodeling and diminish her skeletal F- burden.
CONCLUSION
Due to the prolonged half-life of F- in bone, SF can cause fracturing long after F- exposure stops. Anabolic therapy approved for osteoporosis, such as abaloparatide, may induce mineralized bone turnover to replace the poorly mineralized osteomalacic bone characteristic of SF and thereby diminish fracture risk. Following abaloparatide treatment for our patient, there was a decrease in bone density as well as a reduction in F- levels.
PubMed: 38847810
DOI: 10.1007/s00198-024-07137-x -
Osteoporosis International : a Journal... Jun 2024Vitamin D is important for musculoskeletal health. Concentrations of 25-hydroxyvitamin D, the most commonly measured metabolite, vary markedly around the world and are...
Vitamin D is important for musculoskeletal health. Concentrations of 25-hydroxyvitamin D, the most commonly measured metabolite, vary markedly around the world and are influenced by many factors including sun exposure, skin pigmentation, covering, season and supplement use. Whilst overt vitamin D deficiency with biochemical consequences presents an increased risk of severe sequelae such as rickets, osteomalacia or cardiomyopathy and usually warrants prompt replacement treatment, the role of vitamin D supplementation in the population presents a different set of considerations. Here the issue is to keep, on average, the population at a level whereby the risk of adverse health outcomes in the population is minimised. This position paper, which complements recently published work from the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases, addresses key considerations regarding vitamin D assessment and intervention from the population perspective. This position paper, on behalf of the International Osteoporosis Foundation Vitamin D Working Group, summarises the burden and possible amelioration of vitamin D deficiency in global populations. It addresses key issues including screening, supplementation and food fortification.
PubMed: 38836946
DOI: 10.1007/s00198-024-07127-z -
Journal of Bone and Mineral Research :... Jun 2024X-linked hypophosphatemia (XLH) is caused by mutations in PHEX, leading to rickets and osteomalacia. Adults affected with XLH develop a mineralization of the bone-tendon...
X-linked hypophosphatemia (XLH) is caused by mutations in PHEX, leading to rickets and osteomalacia. Adults affected with XLH develop a mineralization of the bone-tendon attachment site (enthesis), called enthesopathy, which causes significant pain and impaired movement. Entheses in mice with XLH (Hyp) have enhanced Bone Morphogenetic Protein (BMP) and Indian hedgehog (IHH) signaling. Treatment of Hyp mice with the BMP signaling blocker palovarotene attenuated BMP/IHH signaling in Hyp entheses, thus indicating that BMP signaling plays a pathogenic role in enthesopathy development and that IHH signaling is activated by BMP signaling in entheses. It was previously shown that mRNA expression of Gdf5 is enhanced in Hyp entheses at P14. Thus, to determine a role for GDF5 in enthesopathy development, Gdf5 was deleted globally in Hyp mice and conditionally in Scx + cells of Hyp mice. In both murine models, BMP/IHH signaling was similarly decreased in Hyp entheses, leading to decreased enthesopathy. BMP/IHH signaling remained unaffected in WT entheses with decreased Gdf5 expression. Moreover, deletion of Gdf5 in Hyp entheses starting at P30, after enthesopathy has developed, partially reversed enthesopathy. Taken together, these results demonstrate that while GDF5 is not essential for modulating BMP/IHH signaling in WT entheses, inappropriate GDF5 activity in Scx + cells contributes to XLH enthesopathy development. As such, inhibition of GDF5 signaling may be beneficial for the treatment of XLH enthesopathy.
PubMed: 38836497
DOI: 10.1093/jbmr/zjae086 -
JCEM Case Reports Jun 2024[This corrects the article DOI: 10.1210/jcemcr/luae044.].
[This corrects the article DOI: 10.1210/jcemcr/luae044.].
PubMed: 38827434
DOI: 10.1210/jcemcr/luae111 -
JCEM Case Reports Jun 2024Tumor-induced osteomalacia (TIO) is an exceedingly rare paraneoplastic condition characterized by hypophosphatemia, osteomalacia, fragility fractures, and fatigue. A...
Tumor-induced osteomalacia (TIO) is an exceedingly rare paraneoplastic condition characterized by hypophosphatemia, osteomalacia, fragility fractures, and fatigue. A 39-year-old man was assessed for hemoptysis, pathological rib fractures, and fatigue, and was found to have a chest mass with lung metastasis. Biopsy of the mass suggested high-grade epithelioid and spindle cell neoplasm. He was initially treated for soft tissue sarcoma with an ifosfamide-based regimen and developed Fanconi syndrome that resolved on cessation of ifosfamide. Serum phosphate remained low. A low tubular maximum reabsorption of phosphate to glomerular filtration rate ratio (TmP/GFR) indicated disproportionate phosphaturia, while a severely elevated fibroblast growth factor-23 (FGF23) level enabled a diagnosis of TIO. He was started on phosphate and calcitriol supplementation. Subsequent next-generation sequencing demonstrated a -fusion mutation, leading to reclassification of his malignancy to a sarcomatoid non-small cell lung carcinoma. He was switched to selpercatinib, a targeted -kinase inhibitor approved for locally advanced or metastatic -fusion-positive solid tumors. This induced tumor remission with subsequent normalization of his FGF23 levels and hypophosphatemia. Despite the presence of a confounding etiology like drug-induced Fanconi syndrome, persistence of hypophosphatemia should prompt a workup of TIO, especially in the presence of a tumor.
PubMed: 38817847
DOI: 10.1210/jcemcr/luae101 -
Cureus Apr 2024The synthesis and absorption of Vitamin D play crucial roles in numerous bodily functions, yet deficiencies persist due to factors like insufficient sunlight exposure... (Review)
Review
The synthesis and absorption of Vitamin D play crucial roles in numerous bodily functions, yet deficiencies persist due to factors like insufficient sunlight exposure and dietary inadequacy. Research underscores the significance of lifestyle elements such as diet, sun exposure, and physical activity in maintaining optimal Vitamin D levels. Strategies aimed at tackling deficiencies emphasize supplementation alongside lifestyle adjustments, especially in regions with abundant sunlight like the Middle East and North Africa (MENA). Despite the abundance of sunshine in the Arab world, there remains a prevalent issue of Vitamin D deficiency. This problem arises from various factors, including cultural practices such as traditional clothing covering most skin areas, which limit sun exposure, and environmental factors like air pollution that reduce UV penetration. Dietary habits and lifestyle choices also contribute to this deficiency. Dealing with the ongoing pandemic requires a focused effort to enhance awareness. While some individuals may recognize common diseases caused by Vitamin D deficiency, such as rickets and osteomalacia, many remain unaware of the broader health risks associated with the condition, including non-skeletal manifestations. Additionally, there is a lack of understanding regarding the numerous hidden benefits of this hormone. Therefore, prioritizing educational initiatives that delve into these aspects is essential to effectively combat the current health crisis. This literature review aims to report both skeletal and extraskeletal consequences of hypovitaminosis and briefly discuss the cause of paradoxical vitamin D deficiency in sunny regions like the MENA. This was done by reviewing pertinent articles published between January 2000 and January 2024, sourced from databases such as PubMed, UpToDate, Scopus, and CINAHL, focusing exclusively on English language literature and using keywords such as "Vitamin D deficiency" and "Extraskeletal manifestations."
PubMed: 38813297
DOI: 10.7759/cureus.59267 -
Calcified Tissue International May 2024Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome characterized by hypophosphatemia, bone mineralization disorders with increased risk of fragility...
Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome characterized by hypophosphatemia, bone mineralization disorders with increased risk of fragility fractures, muscle pain, and progressive weakness. TIO has been associated with increased production of the phosphaturic hormone Fibroblast Growth Factor 23 (FGF23) usually by mesenchymal tumors of soft tissue or bone (Phosphaturic Mesenchymal Tumors-PMTs). In rare cases TIO may be observed in association with other malignancies. We report the case of a 66-year-old woman with an occasional diagnosis of both a PMT and an ovarian cancer during the evaluation of TIO. We also systematically review the literature to discover possible correlations between osteomalacia, FGF23 production, and ovarian cancer. Four studies were eligible for the analysis. Two case reports described an association between TIO development and ovarian cancer, whereas the two case-control studies hypothesized a possible correlation between FGF/FGF receptor axis and cancer development. Although it does not provide conclusive evidence regarding the association between TIO and ovarian cancer, this case report highlights the possibility that in the diagnostic workup of suspected TIO, both FGF23-secreting tumors distinct from PMT and tumors unrelated to the clinical presentation of TIO could be identified. This information is important for guiding successful tumor staging and determining the necessity for surgical intervention and/or eventual adjuvant therapy.
PubMed: 38806758
DOI: 10.1007/s00223-024-01231-2 -
European Journal of Endocrinology Jun 2024A 29-year-old female, born to consanguineous parents, was found with unmeasurable levels of vitamin D (<10 nmol/L) after routine biochemical screening during her first...
A 29-year-old female, born to consanguineous parents, was found with unmeasurable levels of vitamin D (<10 nmol/L) after routine biochemical screening during her first pregnancy. She did not respond to either oral or intramuscular vitamin D supplementation and was an otherwise healthy young woman, with no signs of rickets, osteomalacia, osteoporosis, or secondary hyperparathyroidism. Western blot analysis revealed total lack of vitamin D binding protein, and next generation sequencing confirmed a novel, pathogenic homozygote loss-of-function mutation in exon 13 of the group-specific component gene, that encodes the poly A tail for vitamin D binding protein. She was therefore diagnosed with hereditary DBP deficiency, and vitamin D supplementation was diminished to life-long regular vitamin D supplementation (25 μg per day). This case is extremely interesting, as it expands our knowledge of vitamin D physiology and supports the free hormone hypothesis, given that the patient was asymptomatic despite no measurable levels of vitamin D.
Topics: Humans; Female; Adult; Vitamin D; Vitamin D Deficiency; Vitamin D-Binding Protein; Homozygote; Loss of Function Mutation
PubMed: 38788201
DOI: 10.1093/ejendo/lvae061 -
Advances in Food and Nutrition Research 2024Historically vitamin D deficiency had devastating consequences for children causing rickets resulting in severe bone deformities often leading to death. The mystery of... (Review)
Review
Historically vitamin D deficiency had devastating consequences for children causing rickets resulting in severe bone deformities often leading to death. The mystery of the cause of rickets finally came to light when it was observed that cod liver oil and sunlight could prevent and cure rickets. The first vitamin D to be discovered was vitamin D from ergosterol in ultraviolet irradiated yeast. Vitamin D was discovered from UV exposure to the skin. Investigations revealed the two major functions of vitamin D were to increase intestinal calcium and phosphate absorption and mobilize calcium from the skeleton to maintain calcium and phosphorus homeostasis. Later studies demonstrated that vitamin D does not have an active role in bone mineralization. Vitamin D deficiency results in secondary hyperparathyroidism increasing bone resorption. As a result, this decreases bone mineral content and compromises the architectural integrity increasing risk for fracture. Vitamin D deficiency has also been shown to enhance aging of the bone causing cracks and enhancing bone fractures. Vitamin D deficiency also causes osteomalacia. Therefore, vitamin D sufficiency is extremely important to maximize bone health throughout life. It helps to prevent bone loss, but it cannot restore bone loss due to increased bone resorption that can occur under a variety of circumstances including menopause. The Endocrine Society Guidelines recommends for all ages that adequate vitamin D obtained from the sun, foods and supplements is necessary in order to maintain a circulating concentration of 25-hydroxyvitamin D of at least 30 ng/mL for maximum bone health.
Topics: Humans; Vitamin D; Vitamin D Deficiency; Bone and Bones; Rickets; Bone Density; Osteomalacia; Dietary Supplements
PubMed: 38777417
DOI: 10.1016/bs.afnr.2024.04.002 -
Annals of Surgery May 2024To assess whether long-term survivors of pancreatic surgery show increased risk to develop impaired bone mineral density, osteoporosis, and vitamin D deficiency.
OBJECTIVE
To assess whether long-term survivors of pancreatic surgery show increased risk to develop impaired bone mineral density, osteoporosis, and vitamin D deficiency.
BACKGROUND
Pancreatic resection poses a risk for malabsorption of fat-soluble vitamins and other micronutrients essential for bone mineralization. Here, we evaluated the long-term effects of pancreatic resection on bone mineral density (BMD) and its clinical sequelae.
METHODS
This was a two-pronged analysis of post-pancreatectomy patients with a follow-up period greater than 3 years comprising (1) a large, propensity score-matched, cohort study based on a multinational federated research network (FRN) and (2) a retrospective single institution review of clinical and radiographic patient data. In the FRN analysis, an initial cohort of 8,423 post-pancreatectomy patients were identified and propensity score-matched with normal controls. The primary endpoint was the 10-year risk of developing osteoporotic pathological fractures and secondary endpoints included diagnosis of osteoporosis, vitamin-D deficiency, and related therapies. The single institution retrospective analysis identified 224 patients who underwent pancreatic resection between 2005 and 2019. BMD was quantified in CT images acquired before and after surgery. BMD trends and related factors were assessed in a time-series mixed effect linear regression model.
RESULTS
A total of 8,080 propensity score-matched pairs were included in the FRN analysis. The analysis revealed a 2.4-fold increase in pathological fractures (P<0.0001) and 1.4-1.5 fold increase in osteoporosis/osteomalacia (P<0.0001) and vitamin-D deficiency (P<0.0001) in post-pancreatectomy patients. Vitamin-D supplements were more common in the pancreatectomy group (OR 1.4, 95% CI 1.28-1.53, P<0.0001), as were specific osteoporosis/osteomalacia treatments such as calcitonin, denosumab, romosozumab, abaloparatide, and teriparatide (OR 2.24, 95%CI 1.69-2.95, P<0.0001). Retrospective analysis of CT imaging revealed that BMD declined more rapidly following pancreatic resection compared to normal historical controls (P=0.015). Older age, pancreatic cancer, and pancreaticoduodenectomy were associated with increased rates of BMD loss (P<0.05, each).
CONCLUSIONS
After pancreatic resection, patients are at higher risk for BMD loss and subsequent fractures. As the cohort of pancreatic resection survivorship grows, attention will need to be paid to focused prevention efforts to reduce BMD loss, osteoporosis, and fractures in these vulnerable patients, with specific attention to the pancreatic cancer population.
PubMed: 38775462
DOI: 10.1097/SLA.0000000000006326