Shannon R Emerzian, Jarred Chow, Ramina Behzad, Mustafa Unal, Daniel J Brooks, I-Hsien Wu, John Gauthier, Surya Vishva Teja Jangolla, Marc Gregory Yu, Hetal S Shah, George L King, Fjola Johannesdottir, Lamya Karim, Elaine W Yu, Mary L Bouxsein
{"title":"Long-duration type 1 diabetes is associated with deficient cortical bone mechanical behavior and altered matrix composition in human femoral bone.","authors":"Shannon R Emerzian, Jarred Chow, Ramina Behzad, Mustafa Unal, Daniel J Brooks, I-Hsien Wu, John Gauthier, Surya Vishva Teja Jangolla, Marc Gregory Yu, Hetal S Shah, George L King, Fjola Johannesdottir, Lamya Karim, Elaine W Yu, Mary L Bouxsein","doi":"10.1093/jbmr/zjae184","DOIUrl":"10.1093/jbmr/zjae184","url":null,"abstract":"<p><p>Type 1 diabetes (T1D) is associated with an increased risk of hip fracture beyond what can be explained by reduced bone mineral density, possibly due to changes in bone material from accumulation of advanced glycation end-products (AGEs) and altered matrix composition, though data from human cortical bone in T1D are limited. The objective of this study was to evaluate cortical bone material behavior in T1D by examining specimens from cadaveric femora from older adults with long-duration T1D (≥50 yr; n = 20) and age- and sex-matched nondiabetic controls (n = 14). Cortical bone was assessed by mechanical testing (4-point bending, cyclic reference point indentation, impact microindentation), AGE quantification [total fluorescent AGEs, pentosidine, carboxymethyl lysine (CML)], and matrix composition via Raman spectroscopy. Cortical bone from older adults with T1D had diminished postyield toughness to fracture (-30%, p = .036), elevated levels of AGEs (pentosidine, +17%, p = .039), lower mineral crystallinity (-1.4%, p = .010), greater proline hydroxylation (+1.9%, p = .009), and reduced glycosaminoglycan (GAG) content (-1.3%, p < .03) compared to nondiabetics. In multiple regression models to predict cortical bone toughness, cortical tissue mineral density, CML, and Raman spectroscopic measures of enzymatic collagen crosslinks and GAG content remained highly significant predictors of toughness, while diabetic status was no longer significant (adjusted R2 > 0.60, p < .001). Thus, the impairment of cortical bone to absorb energy following long-duration T1D is well explained by AGE accumulation and modifications to the bone matrix. These results provide novel insight into the pathogenesis of skeletal fragility in individuals with T1D.</p>","PeriodicalId":185,"journal":{"name":"Journal of Bone and Mineral Research","volume":" ","pages":"87-99"},"PeriodicalIF":5.1,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11700620/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142674453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Paul J Childress, Jeffery J Nielsen, Thomas B Bemenderfer, Ushashi C Dadwal, Nabarun Chakraborty, Jonathan S Harris, Monique Bethel, Marta B Alvarez, Aamir Tucker, Alexander R Wessel, Patrick D Millikan, Jonathan H Wilhite, Andrew Engle, Alexander Brinker, Jeffrey D Rytlewski, David C Scofield, Kaitlyn S Griffin, W Christopher Shelley, Kelli J Manikowski, Krista L Jackson, Stacy-Ann Miller, Ying-Hua Cheng, Joydeep Ghosh, Patrick L Mulcrone, Edward F Srour, Mervin C Yoder, Roman M Natoli, Karl D Shively, Aarti Gautam, Rasha Hammamieh, Stewart A Low, Philip S Low, Todd O McKinley, Jeffrey O Anglen, Jonathan W Lowery, Tien-Min G Chu, Melissa A Kacena
{"title":"Thrombopoietic agents enhance bone healing in mice, rats, and pigs.","authors":"Paul J Childress, Jeffery J Nielsen, Thomas B Bemenderfer, Ushashi C Dadwal, Nabarun Chakraborty, Jonathan S Harris, Monique Bethel, Marta B Alvarez, Aamir Tucker, Alexander R Wessel, Patrick D Millikan, Jonathan H Wilhite, Andrew Engle, Alexander Brinker, Jeffrey D Rytlewski, David C Scofield, Kaitlyn S Griffin, W Christopher Shelley, Kelli J Manikowski, Krista L Jackson, Stacy-Ann Miller, Ying-Hua Cheng, Joydeep Ghosh, Patrick L Mulcrone, Edward F Srour, Mervin C Yoder, Roman M Natoli, Karl D Shively, Aarti Gautam, Rasha Hammamieh, Stewart A Low, Philip S Low, Todd O McKinley, Jeffrey O Anglen, Jonathan W Lowery, Tien-Min G Chu, Melissa A Kacena","doi":"10.1093/jbmr/zjae191","DOIUrl":"10.1093/jbmr/zjae191","url":null,"abstract":"<p><p>Achieving bone union remains a significant clinical dilemma. The use of osteoinductive agents, specifically bone morphogenetic proteins (BMPs), has gained wide attention. However, multiple side effects, including increased incidence of cancer, have renewed interest in investigating alternatives that provide safer, yet effective bone regeneration. Here we demonstrate the robust bone healing capabilities of the main megakaryocyte (MK) growth factor, thrombopoietin (TPO), and second-generation TPO agents using multiple animal models, including mice, rats, and pigs. This bone healing activity is shown in two fracture models (critical-sized defect [CSD] and closed fracture) and with local or systemic administration. Our transcriptomic analyses, cellular studies, and protein arrays demonstrate that TPO enhances multiple cellular processes important to fracture healing, particularly angiogenesis, which is required for bone union. Finally, the therapeutic potential of thrombopoietic agents is high since they are used in the clinic for other indications (eg, thrombocytopenia) with established safety profiles and act upon a narrowly defined population of cells.</p>","PeriodicalId":185,"journal":{"name":"Journal of Bone and Mineral Research","volume":" ","pages":"125-139"},"PeriodicalIF":5.1,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142680074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"One day at a time: understanding how 24-hr physical activity, sedentary behavior and sleep patterns influence falls and fracture risk.","authors":"Costas Glavas, David Scott","doi":"10.1093/jbmr/zjae188","DOIUrl":"10.1093/jbmr/zjae188","url":null,"abstract":"","PeriodicalId":185,"journal":{"name":"Journal of Bone and Mineral Research","volume":" ","pages":"1-2"},"PeriodicalIF":5.1,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142674455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sanchita Agarwal, Dany El-Najjar, Ananya Kondapalli, Nayoung Kil, Mafo Kamanda-Kosseh, Mariana Bucovsky, Ivelisse Colon, Joan M Lappe, Julie Stubby, Robert R Recker, X Edward Guo, Elizabeth Shane, Adi Cohen
{"title":"HR-pQCT reveals marked trabecular and cortical structural deficits in women with pregnancy and lactation-associated osteoporosis (PLO).","authors":"Sanchita Agarwal, Dany El-Najjar, Ananya Kondapalli, Nayoung Kil, Mafo Kamanda-Kosseh, Mariana Bucovsky, Ivelisse Colon, Joan M Lappe, Julie Stubby, Robert R Recker, X Edward Guo, Elizabeth Shane, Adi Cohen","doi":"10.1093/jbmr/zjae167","DOIUrl":"10.1093/jbmr/zjae167","url":null,"abstract":"<p><p>Pregnancy and lactation-associated osteoporosis (PLO) is a rare presentation of early-onset osteoporosis characterized by low trauma and spontaneous fractures during late pregnancy/lactation. Herein, we report areal BMD (aBMD) by DXA and volumetric BMD (vBMD), microarchitecture, and strength at the distal radius and tibia by HR-pQCT in 59 women with PLO-in comparison to both healthy premenopausal controls (n = 28) and premenopausal women with idiopathic osteoporotic fractures not associated with pregnancy/lactation (non-PLO IOP; n = 50). Women with PLO (aged 34 ± 6 yr) had a more severe clinical presentation than non-PLO IOP: 80% had vertebral and 92% had multiple fractures (p<.001). They had lower DXA aBMD at all sites vs Controls (all p<.001) and non-PLO IOP (all p<.05). By HR-pQCT, PLO had deficits in all radial/tibial density and most microarchitecture parameters and lower bone strength than controls (all p<.001). Compared to non-PLO IOP, PLO had lower total and trabecular density at radius and tibia (all p ≤ .01) and significant deficits in trabecular microstructure and cortical thickness at the radius only. We studied PLO subgroups with clinical factors potentially related to bone physiology: Within PLO, women with vertebral fractures had lower spine aBMD and higher tibial cortical porosity but were otherwise structurally similar to the nonvertebral group. Those with prior heparin exposure had larger bone size and trabecular area, and those with renal stones had smaller bone size and lower 1/3 radius aBMD. We also compared groups based on postpartum timing: Recent PLO (n = 25) evaluated ≤12 M postpartum, before expected recovery of pregnancy/lactation bone loss, had significantly lower aBMD than distant PLO (n = 34) evaluated >12 M postpartum. However, radial/tibial HR-pQCT measures did not differ, suggesting pre-existing and/or persistent structural deficits. This structural study increases our mechanistic understanding of the severe bone fragility presentation that characterizes PLO and also highlights areas of potential mechanistic heterogeneity that require additional investigation.</p>","PeriodicalId":185,"journal":{"name":"Journal of Bone and Mineral Research","volume":" ","pages":"38-49"},"PeriodicalIF":5.1,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142454264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Milena Dimori, Mahtab Toulany, Lira Samia Sultana, Melda Onal, Jeff D Thostenson, John L Carroll, Charles A O'Brien, Roy Morello
{"title":"A new Col1a1 conditional knock-in mouse model to study osteogenesis imperfecta.","authors":"Milena Dimori, Mahtab Toulany, Lira Samia Sultana, Melda Onal, Jeff D Thostenson, John L Carroll, Charles A O'Brien, Roy Morello","doi":"10.1093/jbmr/zjae189","DOIUrl":"10.1093/jbmr/zjae189","url":null,"abstract":"<p><p>Osteogenesis imperfecta (OI) constitutes a family of bone fragility disorders characterized by both genetic and clinical heterogeneity. Several different mouse models reproduce the classic features of OI, and the most commonly studied carry either a spontaneous or genetically induced pathogenic variant in the Col1a1 or Col1a2 gene. When OI is caused by primary alterations of type I collagen, it represents a systemic connective tissue disease that, in addition to the skeleton, also affects several extra-skeletal tissues and organs, such as skin, teeth, lung, heart, and others, where the altered type I collagen is also expressed. Currently, existing mouse models harbor a disease-causing genetic variant in all tissues and do not allow assessing the primary vs secondary consequences of the mutation on a specific organ/system. Here, we describe the generation of the first conditional knock-in allele for Col1a1 that can express a severe OI-causing glycine substitution (p.Gly1146Arg) in the triple helical region of α1(I) but only after Cre-driven recombination in the tissue of choice. We called this new dominant allele Col1a1G1146R-Floxed/+ and introduced it into the murine model. We describe its validation by crossing mice carrying this allele with EIIA-Cre expressing mice and showing that offspring with the recombined allele reproduce the classic features of a severe form of OI. The new mouse model will be useful to study the tissue-specific impact of this severe mutation on organs, such as the lung, the heart, and others.</p>","PeriodicalId":185,"journal":{"name":"Journal of Bone and Mineral Research","volume":" ","pages":"114-124"},"PeriodicalIF":5.1,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142680046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"β-Hydroxybutyrate ameliorates osteoarthritis through activation of the ERBB3 signaling pathway in mice.","authors":"Zhiqing Cai, Zhimin Zhang, Jiarong Leng, Mengyun Xie, Kang Zhang, Jingyi Zhang, Haiyan Zhang, Hongling Hu, Yinghu Deng, Xiaochun Bai, Qiancheng Song, Pinglin Lai","doi":"10.1093/jbmr/zjae176","DOIUrl":"10.1093/jbmr/zjae176","url":null,"abstract":"<p><p>The ketogenic diet (KD) has demonstrated efficacy in ameliorating inflammation in rats with osteoarthritis (OA). However, the long-term safety of the KD and the underlying mechanism by which it delays OA remain unclear. We found that while long-term KD could ameliorate OA, it induced severe hepatic steatosis in mice. Consequently, we developed 2 versions of ketogenic-based diets: KD supplemented with vitamin D and intermittent KD. Both KD supplemented with vitamin D and intermittent KD effectively alleviated OA by significantly reducing the levels of inflammatory cytokines, cartilage loss, sensory nerve sprouting, and knee hyperalgesia without inducing hepatic steatosis. Furthermore, β-hydroxybutyrate (β-HB), a convenient energy carrier produced by adipocytes, could ameliorate OA without causing liver lesions. Mechanistically, β-HB enhanced chondrocyte autophagy and reduced apoptosis through the activation of Erb-B2 receptor tyrosine kinase 3 (ERBB3) signaling pathway; a pathway which was down-regulated in the articular chondrocytes from both OA patients and mice. Collectively, our findings highlighted the potential therapeutic value of β-HB and KD supplemented with vitamin D and intermittent KD approaches for managing OA.</p>","PeriodicalId":185,"journal":{"name":"Journal of Bone and Mineral Research","volume":" ","pages":"140-153"},"PeriodicalIF":5.1,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142574994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The challenges of investigating causes and recovery from osteoporosis associated with pregnancy and lactation.","authors":"Christopher S Kovacs","doi":"10.1093/jbmr/zjae180","DOIUrl":"10.1093/jbmr/zjae180","url":null,"abstract":"","PeriodicalId":185,"journal":{"name":"Journal of Bone and Mineral Research","volume":" ","pages":"3-4"},"PeriodicalIF":5.1,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142575006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Modeling of skeletal development and diseases using human pluripotent stem cells.","authors":"Hironori Hojo, Shoichiro Tani, Shinsuke Ohba","doi":"10.1093/jbmr/zjae178","DOIUrl":"10.1093/jbmr/zjae178","url":null,"abstract":"<p><p>Human skeletal elements are formed from distinct origins at distinct positions of the embryo. For example, the neural crest produces the facial bones, the paraxial mesoderm produces the axial skeleton, and the lateral plate mesoderm produces the appendicular skeleton. During skeletal development, different combinations of signaling pathways are coordinated from distinct origins during the sequential developmental stages. Models for human skeletal development have been established using human pluripotent stem cells (hPSCs) and by exploiting our understanding of skeletal development. Stepwise protocols for generating skeletal cells from different origins have been designed to mimic developmental trails. Recently, organoid methods have allowed the multicellular organization of skeletal cell types to recapitulate complicated skeletal development and metabolism. Similarly, several genetic diseases of the skeleton have been modeled using patient-derived induced pluripotent stem cells and genome-editing technologies. Model-based drug screening is a powerful tool for identifying drug candidates. This review briefly summarizes our current understanding of the embryonic development of skeletal tissues and introduces the current state-of-the-art hPSC methods for recapitulating skeletal development, metabolism, and diseases. We also discuss the current limitations and future perspectives for applications of the hPSC-based modeling system in precision medicine in this research field.</p>","PeriodicalId":185,"journal":{"name":"Journal of Bone and Mineral Research","volume":" ","pages":"5-19"},"PeriodicalIF":5.1,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142574965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tamara Jarayseh, Sophie Debaenst, Hanna De Saffel, Toon Rosseel, Mauro Milazzo, Jan Willem Bek, David M Hudson, Filip Van Nieuwerburgh, Yannick Gansemans, Iván Josipovic, Matthieu N Boone, P Eckhard Witten, Andy Willaert, Paul J Coucke
{"title":"Bmpr1aa modulates the severity of the skeletal phenotype in an fkbp10-deficient Bruck syndrome zebrafish model.","authors":"Tamara Jarayseh, Sophie Debaenst, Hanna De Saffel, Toon Rosseel, Mauro Milazzo, Jan Willem Bek, David M Hudson, Filip Van Nieuwerburgh, Yannick Gansemans, Iván Josipovic, Matthieu N Boone, P Eckhard Witten, Andy Willaert, Paul J Coucke","doi":"10.1093/jbmr/zjae185","DOIUrl":"10.1093/jbmr/zjae185","url":null,"abstract":"<p><p>Rare monogenic disorders often exhibit significant phenotypic variability among individuals sharing identical genetic mutations. Bruck syndrome (BS), a prime example, is characterized by bone fragility and congenital contractures, although with a pronounced variability among family members. BS arises from recessive biallelic mutations in FKBP10 or PLOD2. FKBP65, the protein encoded by FKBP10, collaborates with the LH2 enzyme (PLOD2) in type I collagen telopeptide lysine hydroxylation, crucial for collagen cross-linking. To identify potential modifier genes and to investigate the mechanistic role of FKBP10 in BS pathogenesis, we established an fkbp10a knockout zebrafish model. Mass-spectrometry analysis in fkbp10a-/- mutants revealed a generally decreased type I collagen lysyl hydroxylation, paralleled by a wide skeletal variability similar to human patients. Ultrastructural examination of the skeleton in severely affected mutants showed enlarged type I collagen fibrils and disturbed elastin layers. Whole-exome sequencing of 7 mildly and 7 severely affected mutant zebrafish siblings, followed by single nucleotide polymorphism-based linkage analysis, indicated a linked region on chromosome 13, which segregates with phenotypic severity. Transcriptome analysis identified 6 differentially expressed genes (DEGs) between mildly and severely affected mutants. The convergence of genes within the linked region and DEGs highlighted bmpr1aa as a potential modifier gene, as its reduced expression correlates with increased skeletal severity. In summary, our study provides deeper insights into the role of FKBP10 in BS pathogenesis. Additionally, we identified a pivotal gene that influences phenotypic severity in a zebrafish model of BS. These findings hold promise for novel treatments in the field of bone diseases.</p>","PeriodicalId":185,"journal":{"name":"Journal of Bone and Mineral Research","volume":" ","pages":"154-166"},"PeriodicalIF":5.1,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142680051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tafadzwa Madanhire, Kate A Ward, Amy Macdougall, Nuredin Mohammed, Suzanne Filteau, Lackson Kasonka, Hilda B Mabuda, Molly Chisenga, Jonathan Tang, William D Fraser, Tsitsi Bandason, Nyasha V Dzavakwa, Victoria Simms, Rashida A Ferrand, Celia L Gregson
{"title":"The role of vitamin D metabolism in regulating bone turnover in adolescents with perinatally-acquired HIV in Southern Africa: a cross-sectional study in Zimbabwe and Zambia.","authors":"Tafadzwa Madanhire, Kate A Ward, Amy Macdougall, Nuredin Mohammed, Suzanne Filteau, Lackson Kasonka, Hilda B Mabuda, Molly Chisenga, Jonathan Tang, William D Fraser, Tsitsi Bandason, Nyasha V Dzavakwa, Victoria Simms, Rashida A Ferrand, Celia L Gregson","doi":"10.1093/jbmr/zjae190","DOIUrl":"10.1093/jbmr/zjae190","url":null,"abstract":"<p><p>Vitamin D dysregulation can occur in people living with HIV, disrupting calcium homeostasis, and bone turnover. We aimed to investigate the potential mechanisms by which vitamin D regulates bone turnover in adolescents living with perinatally-acquired HIV (ALWH) in Southern Africa. A pre-planned secondary analysis was performed of baseline data from the vitamin D for adolescents with HIV to reduce musculoskeletal morbidity and immunopathology trial (PACTR20200989766029) which enrolled ALWH (11-19 yr) taking antiretroviral therapy for ≥6 mo, and recorded socio-demographic, clinical and dietary data. After over-night fasting, vitamin D metabolites (25(OH)D, 1,25(OH)2D, and 24,25(OH)2D), intact parathyroid hormone (PTH), and bone turnover markers (BTMs) (C-terminal telopeptide of type I collagen (CTX) and procollagen type 1 N-terminal propeptide (P1NP)) were measured. Tandem Mass Spectrometry measured vitamin D metabolites, while intact PTH and BTMs were analyzed by electrochemiluminescence immunoassay. Stratified by 25(OH)D (<75 vs ≥75 nmol/L), associations between standardized concentrations (β = standard deviations) of vitamin D metabolites, intact PTH and BTMs were assessed using structural equations modelling (SEM) adjusted for age, sex, and country (Zimbabwe/Zambia). Among the 842 ALWH enrolled, the median dietary calcium intake was 100 mg (IQR: 55-145). The SEM showed PTH was positively associated (β: 0.21; 95% CI, 0.1, 0.32) with 1,25(OH)2D, only when 25(OH)D was <75 vs ≥75 nmol/L (β: 0.23; 95%CI, -0.13, 0.59), with evidence of an interaction (β: -0.11; 95%CI, -0.20, -0.02). A positive relationship between 25(OH)D and 24,25(OH)2D was seen irrespective of 25(OH)D concentration. 24,25(OH)2D was inversely related to BTMs, particularly when 25(OH)D was <75 nmol/L (CTX: β: -0.15; 95% CI, -0.24, -0.06 and P1NP: β: -0.14; 95%CI, -0.22, -0.06). There was interaction between dietary calcium and 25(OH)D on PTH (β: -0.15; 95% CI, -0.22, -0.07) suggesting an interaction between low 25(OH)D and low dietary calcium which increases PTH. In conclusion, associations between 25(OH)D, PTH, 1,25(OH)2D, and BTMs in ALWH appear dependent upon 25(OH)D concentrations <75 nmol/L and calcium intake. A novel, potentially causal pathway between 25(OH)D, 24,25(OH)2D, and BTMs was seen. Findings enhance understanding of vitamin D metabolism in people living with HIV.</p>","PeriodicalId":185,"journal":{"name":"Journal of Bone and Mineral Research","volume":" ","pages":"59-68"},"PeriodicalIF":5.1,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142680058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}