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Additional file 5: Supplementary File 5. Meta-analyses results. Results of meta-analyses (forest plot) of randomized controlled trials identified from systematic reviews included in this overview review for functioning, quality of life, length of stay, discharge destination and mortality. Each meta-analysis is accompanied by a table which describes the characteristics of each randomized controlled trial included in each meta-analysis.

Additional file 6: Supplementary File 6. Treatment ingredient meta-analyses results. Results of meta-analyses (forest plot) of randomized controlled trials identified from systematic reviews included in this overview review by treatment ingredient.

Additional file 1: Supplementary File 1. Search strategies. Search strategies for electronic databases of published and unpublished evidence.

Additional file 1: Supplementary table 1. Demographics of the total study population by high bone mass status.

Additional file 7: Supplementary File 7. Narrative results. Results of randomized controlled trials identified from systematic reviews included in this overview review which were not incorporated into the meta-analyses and reasons why they were not incorporated.

Additional file 4: Supplementary File 4. Treatment ingredients. Treatment ingredients employed by eligible randomized controlled trials identified from systematic reviews included in this overview review.

Additional file 2: Supplementary File 2. Citation matrix. Citation matrix detailing the identification of unique (non-overlapping) randomized controlled trials from systematic reviews included in this overview review.

Additional file 3: Supplementary File 3. Characteristics of randomized controlled trials. Characteristics of eligible randomized controlled trials identified from systematic reviews included in this overview review.

We previously reported an association between high bone mass (HBM) and a bone-forming phenotype of radiographic hip osteoarthritis (OA). As knee and hip OA have distinct risk factors, in this study we aimed to determine (i) whether HBM is also associated with knee OA, and (ii) whether the HBM knee OA phenotype demonstrates a similar pattern of radiographic features to that observed at the hip.HBM cases (defined by DXA BMD Z-scores) from the UK-based HBM study were compared with unaffected family controls and general population controls from the Chingford and Hertfordshire cohort studies. A single blinded observer graded AP weight-bearing knee radiographs for features of OA (Kellgren-Lawrence score, osteophytes, joint space narrowing (JSN), sclerosis) using an atlas. Analyses used logistic regression, adjusting a priori for age and gender, and additionally for BMI as a potential mediator of the HBM-OA association, using Stata v12.609 HBM knees in 311 cases (mean age 60.8. years, 74% female) and 1937 control knees in 991 controls (63.4. years, 81% female) were analysed. The prevalence of radiographic knee OA, defined as Kellgren-Lawrence grade. ≥. 2, was increased in cases (31.5% vs. 20.9%), with age and gender adjusted OR [95% CI] 2.38 [1.81, 3.14], p.

INTRODUCTION: In 2008, the UK National Osteoporosis Guideline Group (NOGG) produced a guideline on the prevention and treatment of osteoporosis, with an update in 2013. This paper presents a major update of the guideline, the scope of which is to review the assessment and management of osteoporosis and the prevention of fragility fractures in postmenopausal women and men age 50 years or over. \ud \ud METHODS: Where available, systematic reviews, meta-analyses and randomised controlled trials were used to provide the evidence base. Conclusions and recommendations were systematically graded according to the strength of the available evidence. \ud \ud RESULTS: Review of the evidence and recommendations are provided for the diagnosis of osteoporosis, fracture-risk assessment, lifestyle measures and pharmacological interventions, duration and monitoring of bisphosphonate therapy, glucocorticoid-induced osteoporosis, osteoporosis in men, postfracture care and intervention thresholds. \ud \ud CONCLUSION: The guideline, which has received accreditation from the National Institute of Health and Care Excellence (NICE), provides a comprehensive overview of the assessment and management of osteoporosis for all healthcare professionals who are involved in its management.

OBJECTIVE: Epidemiological studies have shown an association between increased bone mineral density (BMD) and osteoarthritis (OA), but whether this represents cause or effect remains unclear. In this study, we used a novel approach to investigate this question, determining whether individuals with High Bone Mass (HBM) have a higher prevalence of radiographic hip OA compared with controls. DESIGN: HBM cases came from the UK-based HBM study: HBM was defined by BMD Z-score. Unaffected relatives of index cases were recruited as family controls. Age-stratified random sampling was used to select further population controls from the Chingford and Hertfordshire cohort studies. Pelvic radiographs were pooled and assessed by a single observer blinded to case-control status. Analyses used logistic regression, adjusted for age, gender and body mass index (BMI). RESULTS: 530 HBM hips in 272 cases (mean age 62.9 years, 74% female) and 1702 control hips in 863 controls (mean age 64.8 years, 84% female) were analysed. The prevalence of radiographic OA, defined as Croft score ≥3, was higher in cases compared with controls (20.0% vs 13.6%), with adjusted odds ratio (OR) [95% CI] 1.52 [1.09, 2.11], P = 0.013. Osteophytes (OR 2.12 [1.61, 2.79], P

Sarcopenia is associated with a greater fracture risk. This relationship was originally thought to be explained by an increased risk of falls in sarcopenic individuals. However, in addition, there is growing evidence of a functional muscle-bone unit in which bone health may be directly influenced by muscle function. Because a definition of sarcopenia encompasses muscle size, strength, and physical performance, we investigated relationships for each of these with bone size, bone density, and bone strength to interrogate these hypotheses further in participants from the Hertfordshire Cohort Study. A total of 313 men and 318 women underwent baseline assessment of health and detailed anthropometric measurements. Muscle strength was measured by grip strength, and physical performance was determined by gait speed. Peripheral quantitative computed tomography (pQCT) examination of the calf and forearm was performed to assess muscle cross-sectional area (mCSA) at the 66% level and bone structure (radius 4% and 66% levels; tibia 4% and 38% levels). Muscle size was positively associated with bone size (distal radius total bone area β = 17.5 mm2 /SD [12.0, 22.9]) and strength (strength strain index (β = 23.3 mm3 /SD [18.2, 28.4]) amongst women (p

Summary: Individuals with low socio-economic status (SES) have a more than 25% higher risk of fragility fractures than individuals with high SES. Body mass index and lifestyle appear to mediate the effect of SES on fracture risk. Strategies to prevent fractures should aim to reduce unhealthy behaviours through tackling structural inequalities. Introduction: This systematic review and meta-analysis aimed to evaluate the impact of socio-economic status (SES) on fragility fracture risk. Methods: Medline, Embase, and CINAHL databases were searched from inception to 28 April 2021 for studies reporting an association between SES and fragility fracture risk among individuals aged ≥50 years. Risk ratios (RR) were combined in meta-analyses using random restricted maximum likelihood models, for individual-based (education, income, occupation, cohabitation) and area-based (Index of Multiple Deprivation, area income) SES measures. Results: A total of 61 studies from 26 different countries including more than 19 million individuals were included. Individual-based low SES was associated with an increased risk of fragility fracture (RR 1.27 [95% CI 1.12, 1.44]), whilst no clear association was seen when area-based measures were used (RR 1.08 [0.91, 1.30]). The strength of associations was influenced by the type and number of covariates included in statistical models: RR 2.69 [1.60, 4.53] for individual-based studies adjusting for age, sex and BMI, compared with RR 1.06 [0.92, 1.22] when also adjusted for health behaviours (smoking, alcohol, and physical activity). Overall, the quality of the evidence was moderate. Conclusion: Our results show that low SES, measured at the individual level, is a risk factor for fragility fracture. Low BMI and unhealthy behaviours are important mediators of the effect of SES on fracture risk. Strategies to prevent fractures and reduce unhealthy behaviours should aim to tackle structural inequalities in society thereby reducing health inequalities in fragility fracture incidence.

BackgroundBone health and fracture risk reduction are increasingly recognized as important issues in Parkinson’s disease (PD). However, the evidence for fracture risk management in atypical parkinsonism (AP) is less clear. Guidance on management of bone health in PD has recently been published. ObjectivesTo evaluate the outcome of fracture risk assessment in a cohort of patients with AP, compared to a population with idiopathic PD.MethodsWe did a cross-sectional study of patients with PD or AP who had fracture risk assessed at two tertiary movement disorder centres. Data on fracture risk as assessed using QFracture and FRAX were collected. To assess for the effect of age on fracture risk we compared the risks of PD and AP patients aged ≤70 and >70 years.ResultsWe assessed 71 patients with AP and 267 with PD. Age, sex and body mass index were similar between groups; patients with AP were more likely to have fallen in the previous year. Major osteoporotic fracture risk was greater in patients with AP aged ≤70 compared to PD; no differences between groups were seen in those aged >70 years. 76% of those with AP, and 63% with PD, had an estimated fracture risk indicating bone-sparing treatment, but only 33% of patients with AP were receiving this where it was indicated.ConclusionThere is scope for considerable improvement in fracture risk assessment and treatment in atypical parkinsonism, taking into account the worse prognosis of this patient group.

BackgroundHigh bone mass (HBM, BMD Z-score ≥ + 3.2) and cam morphology (bulging of lateral femoral head) are associated with greater odds of prevalent radiographic hip osteoarthritis (rHOA). As cam morphology is itself a manifestation of increased bone deposition around the femoral head, it is conceivable that cam morphology may mediate the relationship between HBM and rHOA. We therefore aimed to determine if individuals with HBM have increased odds of prevalent cam morphology. In addition, we investigated whether the relationship between cam and prevalent and incident osteoarthritis was preserved in a HBM population.MethodsIn the HBM study, a UK based cohort of adults with unexplained HBM and their relatives and spouses (controls), we determined the presence of cam morphology using semi-automatic methods of alpha angle derivation from pelvic radiographs. Associations between HBM status and presence of cam morphology, and between cam morphology and presence of rHOA (or its subphenotypes: osteophytes, joint space narrowing, cysts, and subchondral sclerosis) were determined using multivariable logistic regression, adjusting for age, sex, height, weight, and adolescent physical activity levels. The association between cam at baseline and incidence of rHOA after an average of 8 years was determined. Generalised estimating equations accounted for individual-level clustering.ResultsThe study included 352 individuals, of whom 235 (66.7%) were female and 234 (66.5%) had HBM. Included individuals contributed 694 hips, of which 143 had a cam deformity (20.6%). There was no evidence of an association between HBM and cam morphology (OR = 0.97 [95% CI: 0.63–1.51],p = 0.90) but a strong relationship was observed between cam morphology and rHOA (OR = 3.96 [2.63–5.98],p = 5.46 × 10–11) and rHOA subphenotypes joint space narrowing (OR = 3.70 [2.48–5.54],p = 1.76 × 10–10), subchondral sclerosis (OR = 3.28 [1.60–6.60],p = 9.57 × 10–4) and osteophytes (OR = 3.01 [1.87–4.87],p = 6.37 × 10–6). Cam morphology was not associated with incident osteoarthritis (OR = 0.76 [0.16–3.49],p = 0.72).ConclusionsThe relationship between cam morphology and rHOA seen in other studies is preserved in a HBM population. This study suggests that the risk of OA conferred by high BMD and by cam morphology are mediated via distinct pathways.

Background: This trial aimed to determine the efficacy of leucine and/or perindopril in improving physical function in older people with sarcopenia. Methods: Placebo-controlled, parallel group, double-blind, randomized two-by-two factorial trial. We recruited adults aged ≥ 70 years with sarcopenia, defined as low gait speed (

Summary: Additional physiotherapy in the first postoperative week was associated with fewer days to discharge after hip fracture surgery. A 7-day physiotherapy service in the first postoperative week should be considered as a new key performance indicator in evaluating the quality of care for patients admitted with a hip fracture. Introduction: To examine the association between physiotherapy in the first week after hip fracture surgery and discharge from acute hospital. Methods: We linked data from the UK Physiotherapy Hip Fracture Sprint Audit to hospital records for 5395 patients with hip fracture in May and June 2017. We estimated the association between the number of days patients received physiotherapy in the first postoperative week; its overall duration (< 2 h, ≥ 2 h; 30-min increment) and type (mobilisation alone, mobilisation and exercise) and the cumulative probability of discharge from acute hospital over 30 days, using proportional odds regression adjusted for confounders and the competing risk of death. Results: The crude and adjusted odds ratios of discharge were 1.24 (95% CI 1.19–1.30) and 1.26 (95% CI 1.19–1.33) for an additional day of physiotherapy, 1.34 (95% CI 1.18–1.52) and 1.33 (95% CI 1.12–1.57) for ≥ 2 versus < 2 h physiotherapy, and 1.11 (95% CI 1.08–1.15) and 1.10 (95% CI 1.05–1.15) for an additional 30-min of physiotherapy. Physiotherapy type was not associated with discharge. Conclusion: We report an association between physiotherapy and discharge after hip fracture. An average UK hospital admitting 375 patients annually may save 456 bed-days if current provision increased so all patients with hip fracture received physiotherapy on 6–7 days in the first postoperative week. A 7-day physiotherapy service totalling at least 2 h in the first postoperative week may be considered a key performance indicator of acute care quality after hip fracture.

The human microbiota functions at the interface between diet, medication-use, lifestyle, host immune development and health. It is therefore closely aligned with many of the recognised modifiable factors that influence bone mass accrual in the young, and bone maintenance and skeletal decline in older populations. While understanding of the relationship between micro-organisms and bone health is still in its infancy, two decades of broader microbiome research and discovery supports a role of the human gut microbiome in the regulation of bone metabolism and pathogenesis of osteoporosis as well as its prevention and treatment. Pre-clinical research has demonstrated biological interactions between the microbiome and bone metabolism. Furthermore, observational studies and randomized clinical trials have indicated that therapeutic manipulation of the microbiota by oral administration of probiotics may influence bone turnover and prevent bone loss in humans. In this paper, we summarize the content, discussion and conclusions of a workshop held by the Osteoporosis and Bone Research Academy of the Royal Osteoporosis Society in October, 2020. We provide a detailed review of the literature examining the relationship between the microbiota and bone health in animal models and in humans, as well as formulating the agenda for key research priorities required to advance this field. We also underscore the potential pitfalls in this research field that should be avoided and provide methodological recommendations to facilitate bridging the gap from promising concept to a potential cause and intervention target for osteoporosis.

Fat distribution is an independent cardiometabolic risk factor. However, its molecular and cellular underpinnings remain obscure. Here we demonstrate that two independent GWAS signals at RSPO3, which are associated with increased body mass index-adjusted waist-to-hip ratio, act to specifically increase RSPO3 expression in subcutaneous adipocytes. These variants are also associated with reduced lower-body fat, enlarged gluteal adipocytes and insulin resistance. Based on human cellular studies RSPO3 may limit gluteofemoral adipose tissue (AT) expansion by suppressing adipogenesis and increasing gluteal adipocyte susceptibility to apoptosis. RSPO3 may also promote upper-body fat distribution by stimulating abdominal adipose progenitor (AP) proliferation. The distinct biological responses elicited by RSPO3 in abdominal versus gluteal APs in vitro are associated with differential changes in WNT signalling. Zebrafish carrying a nonsense rspo3 mutation display altered fat distribution. Our study identifies RSPO3 as an important determinant of peripheral AT storage capacity., Genetic variants at the RSPO3 locus are associated with waist-to-hip ratio (adjusted for BMI). Here, Loh et al. describe two independent RSPO3 signals that associate with body fat distribution, perform fine-mapping and explore the function of RSPO3 in human adipocyte biology and body fat distribution in zebrafish

SUMMARY: Individuals with low socio-economic status (SES) have a higher risk of dying following hip fracture compared with individuals with high SES. Evidence on social inequalities in non-hip fractures is lacking as well as evidence on the impact of SES on health-related quality of life post fracture.INTRODUCTION: Fragility fractures, especially of the hip, cause substantial excess mortality and impairment in health-related quality of life (HRQoL). This systematic review and meta-analysis aimed to investigate the association between socio-economic status (SES) and post-fracture mortality and HRQoL.METHODS: PubMed, EMBASE and CINAHL databases were searched from inception to the last week of November 2018 for studies reporting an association between SES and post-fracture mortality and/or HRQoL among people aged ≥ 50 years. Risk ratios (RRs) were meta-analyzed using a standard inverse-variance-weighted random effects model. Studies using individual-level and area-based SES measures were analyzed separately.RESULTS: A total of 24 studies from 15 different countries and involving more than one million patients with hip fractures were included. The overall risk of mortality within 1-year post-hip fracture in individuals with low SES was 24% higher than in individuals with high SES (RR 1.24, 95% CI 1.19 to 1.29) for individual-level SES measures, and 14% (RR 1.14, 95% CI 1.09 to 1.19) for area-based SES measures. The quality of the evidence for the outcome mortality was moderate. Using individual SES measures, we estimated the excess HRQoL loss to be 5% (95% CI - 1 to 10%) among hip fracture patients with low SES compared with high SES.CONCLUSIONS: We found a consistently increased risk of post-hip fracture mortality with low SES across SES measures and across countries with different political structures and different health and social care infrastructures. The impact of SES on post-fracture HRQoL remains uncertain due to sparse and low-quality evidence.

Objective to determine the extent to which equity factors contributed to eligibility criteria of trials of rehabilitation interventions after hip fracture. We define equity factors as those that stratify healthcare opportunities and outcomes. Design systematic search of MEDLINE, Embase, CINHAL, PEDro, Open Grey, BASE and ClinicalTrials.gov for randomised controlled trials of rehabilitation interventions after hip fracture published between 1 January 2008 and 30 May 2018. Trials not published in English, secondary prevention or new models of service delivery (e.g. orthogeriatric care pathway) were excluded. Duplicate screening for eligibility, risk of bias (Cochrane Risk of Bias Tool) and data extraction (Cochrane’s PROGRESS-Plus framework). Results twenty-three published, eight protocol, four registered ongoing randomised controlled trials (4,449 participants) were identified. A total of 69 equity factors contributed to eligibility criteria of the 35 trials. For more than 50% of trials, potential participants were excluded based on residency in a nursing home, cognitive impairment, mobility/functional impairment, minimum age and/or non-surgical candidacy. Where reported, this equated to the exclusion of 2,383 out of 8,736 (27.3%) potential participants based on equity factors. Residency in a nursing home and cognitive impairment were the main drivers of these exclusions. Conclusion the generalisability of trial results to the underlying population of frail older adults is limited. Yet, this is the evidence base underpinning current service design. Future trials should include participants with cognitive impairment and those admitted from nursing homes. For those excluded, an evidence-informed reasoning for the exclusion should be explicitly stated. PROSPERO CRD42018085930.

Background Generalised high bone mass (HBM), associated with features of a mild skeletal dysplasia, has a prevalence of 0.18% in a UK DXA-scanned adult population. We hypothesized that the genetic component of extreme HBM includes contributions from common variants of small effect and rarer variants of large effect, both enriched in an extreme phenotype cohort. Methods We performed a genome-wide association study (GWAS) of adults with either extreme high or low BMD. Adults included individuals with unexplained extreme HBM (n = 240) from the UK with BMD Z-scores ≥+3.2, high BMD females from the Anglo-Australasian Osteoporosis Genetics Consortium (AOGC) (n = 1055) with Z-scores +1.5 to +4.0 and low BMD females also part of AOGC (n = 900), with Z-scores −1.5 to −4.0. Following imputation, we tested association between 6,379,332 SNPs and total hip and lumbar spine BMD Z-scores. For potential target genes, we assessed expression in human osteoblasts and murine osteocytes. Results We observed significant enrichment for associations with established BMD-associated loci, particularly those known to regulate endochondral ossification and Wnt signalling, suggesting that part of the genetic contribution to unexplained HBM is polygenic. Further, we identified associations exceeding genome-wide significance between BMD and four loci: two established BMD-associated loci (5q14.3 containing MEF2C and 1p36.12 containing WNT4) and two novel loci: 5p13.3 containing NPR3 (rs9292469; minor allele frequency [MAF] = 0.33%) associated with lumbar spine BMD and 11p15.2 containing SPON1 (rs2697825; MAF = 0.17%) associated with total hip BMD. Mouse models with mutations in either Npr3 or Spon1 have been reported, both have altered skeletal phenotypes, providing in vivo validation that these genes are physiologically important in bone. NRP3 regulates endochondral ossification and skeletal growth, whilst SPON1 modulates TGF-β regulated BMP-driven osteoblast differentiation. Rs9292469 (downstream of NPR3) also showed some evidence for association with forearm BMD in the independent GEFOS sample (n = 32,965). We found Spon1 was highly expressed in murine osteocytes from the tibiae, femora, humeri and calvaria, whereas Npr3 expression was more variable. Conclusion We report the most extreme-truncate GWAS of BMD performed to date. Our findings, suggest potentially new anabolic bone regulatory pathways that warrant further study., Highlights • This GWAS found significant enrichment for associations with known BMD loci suggesting a polygenic contribution to high BMD • We identified a novel locus at: 5p13.3 containing NPR3 (lead SNP rs9292469) associated with lumbar spine BMD • We identified a novel locus at: 11p15.2 containing SPON1 (lead SNP rs2697825) associated with total hip BMD • Mouse models with mutations in either Npr3 or Spon1 have been reported, both have altered skeletal phenotypes • Our findings suggest potentially new anabolic bone regulatory pathways; however, further investigation is warranted

Summary:In this study, we report that self-perception of fracture risk captures some aspect of fracture risk not currently measured using conventional fracture prediction tools and is associated with improved medication uptake. It suggests that adequate appreciation of fracture risk may be beneficial and lead to greater healthcare engagement and treatment.Introduction:This study aimed to assess how well self-perception of fracture risk, and fracture risk as estimated by the fracture prediction tool FRAX, related to fracture incidence and uptake and persistence of anti-osteoporosis medication among women participating in the Global Longitudinal study of Osteoporosis in Women (GLOW).Methods:GLOW is an international cohort study involving 723 physician practices across 10 countries in Europe, North America and Australia. Aged ≥ 55 years, 60,393 women completed baseline questionnaires detailing medical history, including co-morbidities, fractures and self-perceived fracture risk (SPR). Annual follow-up included self-reported incident fractures and anti-osteoporosis medication (AOM) use. We calculated FRAX risk without bone mineral density measurement.Results:Of the 39,241 women with at least 1 year of follow-up data, 2132 (5.4%) sustained an incident major osteoporotic fracture over 5 years of follow-up. Within each SPR category, risk of fracture increased as the FRAX categorisation of risk increased. In GLOW, only 11% of women with a lower baseline SPR were taking AOM at baseline, compared with 46% of women with a higher SPR. AOM use tended to increase in the years after a reported fracture. However, women with a lower SPR who were fractured still reported lower AOM rates than women with or without a fracture but had a higher SPR.Conclusions:These results suggest that SPR captures some aspect of fracture risk not currently measured using conventional fracture prediction tools and is also associated with improved medication uptake.

Hip fractures are a major cause of morbidity and mortality in the elderly, and incur high health and social care costs. Given projected population ageing, the number of incident hip fractures is predicted to increase globally. As fracture classification strongly determines the chosen surgical treatment, differences in fracture classification influence patient outcomes and treatment costs. We aimed to create a machine learning method for identifying and classifying hip fractures, and to compare its performance to experienced human observers. We used 3659 hip radiographs, classified by at least two expert clinicians. The machine learning method was able to classify hip fractures with 19% greater accuracy than humans, achieving overall accuracy of 92%.

Background Of the 2 million children living with HIV globally, 90% live in sub-Saharan Africa. Despite antiretroviral therapy, longstanding HIV infection is associated with several chronic complications in children including growth failure, particularly stunting and delayed puberty. Vitamin D deficiency, which is highly prevalent among children living with HIV in sub-Saharan Africa, has a further adverse impact on bone health. This trial aims to establish whether supplementation with vitamin D3 and calcium carbonate improves musculoskeletal health among peripubertal children living with HIV. Methods/design We will conduct an individually randomised, double-blinded, placebo-controlled trial of weekly high-dose vitamin D3 (20,000 IU) plus daily calcium carbonate (500mg) supplementation for 48 weeks. Eight hundred and forty children living with HIV aged 11–19 years taking ART for ≥6 months will be enrolled and followed up for 96 weeks. The primary outcome is total body less-head bone mineral content for lean mass adjusted for height (TBLH-BMCLBM) Z-score at 48 weeks, measured by dual-energy X-ray absorptiometry (DEXA). Secondary outcomes are DEXA-measured lumbar spine bone mineral apparent density Z-score, number of respiratory infections, lean muscle mass and grip strength at 48 and 96 weeks and TBLH-BMCLBMZ-scores at 96 weeks. Sub-studies will investigate the effect of the intervention on vitamin D3 pathway metabolites and markers of bone turnover, intestinal microbiota, and innate and acquired immune function. Discussion This is the largest trial to date of vitamin D supplementation in children living with HIV. Intervening to address deficits in bone accrual in childhood is critical for optimising adolescent and early adult bone health and prevention of later adult osteoporotic fractures. Trial results will draw attention to the need to screen for and treat long-term comorbidities in children living with HIV in resource-limited settings. Trial registration Pan African Clinical Trials Registry PACTR20200989766029. Registered on 3 September 2020

Purpose We estimated direct healthcare costs of hip fracture (HF) management in the South African (SA) public healthcare system.MethodsWe conducted a micro-costing study to estimate costs per patient treated for HF in five regional public sector hospitals in KwaZulu-Natal (KZN), SA. Two hundred consecutive, consenting patients presenting with a fragility HF were prospectively enrolled. Resource use including staff time, consumables, laboratory investigations, radiographs, operating theatre time, surgical implants, medicines, and inpatient days were collected from presentation to discharge. Counts of resources used were multiplied by unit costs, estimated from KZN Department of Health hospital fees manual 2019/20, in local currency (South African Rand, ZAR), and converted to 2020 US$ prices. Generalised linear models estimated total covariate adjusted costs and cost predictors.ResultsThe mean unadjusted cost for HF management was US$6,935 (95% CI; US$6,401-7,620) [ZAR114,179 (95% CI; ZAR105,468-125,335)]. The major cost driver was orthopaedics/surgical ward costs US$5,904 (95% CI; 5,408-6,535), contributing to 85% of total cost. The covariate adjusted cost for HF management was US$6,922 (95% CI; US$6,743-7,118) [ZAR113,976 (95% CI; ZAR111,031-117,197)]. After covariate adjustment, total costs were higher in patients operated under general anaesthesia [US$7,251 (95% CI; US$6,506-7,901)] compared to surgery under spinal anaesthesia US$6,880 (95% CI; US$6,685-7,092) and no surgery US$7,032 (95% CI; US$6,454 -7,651). ConclusionHealthcare costs following a HF are high relative to the gross domestic product per capita, and per capita spending on health in SA. As the population ages, this significant economic burden to the health system will increase.

HIV infection has multi-system adverse effects in children, including on the growing skeleton. We aimed to determine the association between chronic HIV infection and bone architecture (density, size, strength) in peripubertal children. We conducted a cross-sectional study of children aged 8 to 16 years with HIV (CWH) on antiretroviral therapy (ART) and children without HIV (CWOH) recruited from schools and frequency-matched for age strata and sex. Outcomes, measured by tibial peripheral quantitative computed tomography (pQCT), included 4% trabecular and 38% cortical volumetric bone mineral density (vBMD), 4% and 38% cross-sectional area (CSA), and 38% stress-strain index (SSI). Multivariable linear regression tested associations between HIV status and outcomes, stratified by sex and puberty (Tanner 1-2 versus 3-5), adjusting for age, height, fat mass, physical activity, and socioeconomic and orphanhood statuses. We recruited 303 CWH and 306 CWOH; 50% were female. Although CWH were similar in age to CWOH (overall mean ± SD 12.4 ± 2.5 years), more were prepubertal (ie, Tanner 1; 41% versus 23%). Median age at ART initiation was 4 (IQR 2-7) years, whereas median ART duration was 8 (IQR 6-10) years. CWH were more often stunted (height-for-age Z-score

Monogenic high bone mass (HBM) disorders are characterized by an increased amount of bone in general, or at specific sites in the skeleton. Here, we describe 59 HBM disorders with 50 known disease-causing genes from the literature, and we provide an overview of the signaling pathways and mechanisms involved in the pathogenesis of these disorders. Based on this, we classify the known HBM genes into HBM (sub)groups according to uniform Gene Ontology (GO) terminology. This classification system may aid in hypothesis generation, for both wet lab experimental design and clinical genetic screening strategies. We discuss how functional genomics can shape discovery of novel HBM genes and/or mechanisms in the future, through implementation of omics assessments in existing and future model systems. Finally, we address strategies to improve gene identification in unsolved HBM cases and highlight the importance for cross-laboratory collaborations encompassing multidisciplinary efforts to transfer knowledge generated at the bench to the clinic., peer-reviewed

Objectives Observational analyses suggest that high bone mineral density (BMD) is a risk factor for osteoarthritis (OA); it is unclear whether this represents a causal effect or shared aetiology and whether these relationships are body mass index (BMI)-independent. We performed bidirectional Mendelian randomization (MR) to uncover the causal pathways between BMD, BMI and OA. Methods One-sample (1S)MR estimates were generated by two-stage least-squares regression. Unweighted allele scores instrumented each exposure. Two-sample (2S)MR estimates were generated using inverse-variance weighted random-effects meta-analysis. Multivariable MR (MVMR), including BMD and BMI instruments in the same model, determined the BMI-independent causal pathway from BMD to OA. Latent causal variable (LCV) analysis, using weight-adjusted femoral neck (FN)–BMD and hip/knee OA summary statistics, determined whether genetic correlation explained the causal effect of BMD on OA. Results 1SMR provided strong evidence for a causal effect of BMD estimated from heel ultrasound (eBMD) on hip and knee OA {odds ratio [OR]hip = 1.28 [95% confidence interval (CI) = 1.05, 1.57], p = 0.02, ORknee = 1.40 [95% CI = 1.20, 1.63], p = 3 × 10–5, OR per standard deviation [SD] increase}. 2SMR effect sizes were consistent in direction. Results suggested that the causal pathways between eBMD and OA were bidirectional (βhip = 1.10 [95% CI = 0.36, 1.84], p = 0.003, βknee = 4.16 [95% CI = 2.74, 5.57], p = 8 × 10–9, β = SD increase per doubling in risk). MVMR identified a BMI-independent causal pathway between eBMD and hip/knee OA. LCV suggested that genetic correlation (i.e. shared genetic aetiology) did not fully explain the causal effects of BMD on hip/knee OA. Conclusions These results provide evidence for a BMI-independent causal effect of eBMD on OA. Despite evidence of bidirectional effects, the effect of BMD on OA did not appear to be fully explained by shared genetic aetiology, suggesting a direct action of bone on joint deterioration.

Objectives Despite established standards and guidelines, substantial variation remains in the delivery of hip fracture care across the United Kingdom. We aimed to determine which hospital-level organisational factors predict adverse patient outcomes in the months following hip fracture. Methods We examined a national record-linkage cohort of 178,757 patients aged ≥60 years who sustained a hip fracture in England and Wales in 2016–19. Patient-level hospital admissions datasets, National Hip Fracture Database and mortality data were linked to metrics from 18 hospital-level organisational-level audits and reports. Multilevel models identified organisational factors, independent of patient case-mix, associated with three patient outcomes: length of hospital stay (LOS), 30-day all-cause mortality and emergency 30-day readmission. Results Across hospitals mean LOS ranged from 12 to 41.9 days, mean 30-day mortality from 3.7 to 10.4% and mean readmission rates from 3.7 to 30.3%, overall means were 21.4 days, 7.3% and 15.3%, respectively. In all, 22 organisational factors were independently associated with LOS; e.g. a hospital’s ability to mobilise >90% of patients promptly after surgery predicted a 2-day shorter LOS (95% confidence interval [CI]: 1.2–2.6). Ten organisational factors were independently associated with 30-day mortality; e.g. discussion of patient experience feedback at clinical governance meetings and provision of prompt surgery to >80% of patients were each associated with 10% lower mortality (95%CI: 5–15%). Nine organisational factors were independently associated with readmissions; e.g. readmissions were 17% lower if hospitals reported how soon community therapy would start after discharge (95%CI: 9–24%). Conclusions Receipt of hip fracture care should be reliable and equitable across the country. We have identified multiple, potentially modifiable, organisational factors associated with important patient outcomes following hip fracture.

Purpose of Review This paper reviews how bone genetics has contributed to our understanding of the pathogenesis of osteoarthritis. As well as identifying specific genetic mechanisms involved in osteoporosis which also contribute to osteoarthritis, we review whether bone mineral density (BMD) plays a causal role in OA development. Recent Findings We examined whether those genetically predisposed to elevated BMD are at increased risk of developing OA, using our high bone mass (HBM) cohort. HBM individuals were found to have a greater prevalence of OA compared with family controls and greater development of radiographic features of OA over 8 years, with predominantly osteophytic OA. Initial Mendelian randomisation analysis provided additional support for a causal effect of increased BMD on increased OA risk. In contrast, more recent investigation estimates this relationship to be bi-directional. However, both these findings could be explained instead by shared biological pathways. Summary Pathways which contribute to BMD appear to play an important role in OA development, likely reflecting shared common mechanisms as opposed to a causal effect of raised BMD on OA. Studies in HBM individuals suggest this reflects an important role of mechanisms involved in bone formation in OA development; however further work is required to establish whether the same applies to more common forms of OA within the general population.

Background To synthesise the evidence for the effectiveness of inpatient rehabilitation treatment ingredients (versus any comparison) on functioning, quality of life, length of stay, discharge destination, and mortality among older adults with an unplanned hospital admission. Methods A systematic search of Cochrane Library, MEDLINE, Embase, PsychInfo, PEDro, BASE, and OpenGrey for published and unpublished systematic reviews of inpatient rehabilitation interventions for older adults following an unplanned admission to hospital from database inception to December 2020. Duplicate screening for eligibility, quality assessment, and data extraction including extraction of treatment components and their respective ingredients employing the Treatment Theory framework. Random effects meta-analyses were completed overall and by treatment ingredient. Statistical heterogeneity was assessed with the inconsistency-value (I2). Results Systematic reviews (n = 12) of moderate to low quality, including 44 non-overlapping relevant RCTs were included. When incorporated in a rehabilitation intervention, there was a large effect of endurance exercise, early intervention and shaping knowledge on walking endurance after the inpatient stay versus comparison. Early intervention, repeated practice activities, goals and planning, increased medical care and/or discharge planning increased the likelihood of discharge home versus comparison. The evidence for activities of daily living (ADL) was conflicting. Rehabilitation interventions were not effective for functional mobility, strength, or quality of life, or reduce length of stay or mortality. Therefore, we did not explore the potential role of treatment ingredients for these outcomes. Conclusion Benefits observed were often for subgroups of the older adult population e.g., endurance exercise was effective for endurance in older adults with chronic obstructive pulmonary disease, and early intervention was effective for endurance for those with hip fracture. Future research should determine whether the effectiveness of these treatment ingredients observed in subgroups, are generalisable to older adults more broadly. There is a need for more transparent reporting of intervention components and ingredients according to established frameworks to enable future synthesis and/or replication. Trial registration PROSPERO Registration CRD42018114323.

UNLABELLED: Menopause transition is associated with accelerated bone loss, though data are limited from sub-Saharan African (SSA). Our objective was to describe bone density, geometry and estimated strength in women by menopause status and to explore whether patterns differed within those living with HIV.METHODS: Radius and tibia peripheral QCT data were collected for Black South African women (n = 430) aged 40-61 years with verified menopause and HIV status. pQCT outcomes were distal 4 % radius and tibia total cross-sectional area (CSA), total volumetric bone mineral density (vBMD), and compressive bone strength (BSIc); proximal 66 % radius and 38 % tibia cortical vBMD, total CSA, cortical thickness, and Stress-strain Index (SSI). Linear regression assessed associations between pre, peri-, and postmenopausal groups and pQCT outcomes adjusting for age, height, and weight, and then stratified by HIV status. Mean [95%CI] and tests for trend (p-trend) across menopausal groups are presented.RESULTS: Women were mean (SD) age 49.2 (5.3) years, with a body mass index (BMI) of 32.4 (6.3) m/kg 2, and 18 % were living with HIV. After adjustment, later menopause stage was associated with lower 4 % radius total mean [95%CIs] vBMD (premenopause: 345.7 [335.8,355.5] vs. postmenopause: 330.1 [322.7,337.6] mg/cm 3, p-trend = 0.017) and BSIc (premenopause: 0.39 [0.37,0.41] vs. postmenopause: 0.36 [0.35,0.37] g 2/cm 4; p-trend = 0.012). Similar trends were observed at the 66 % radius for cortical vBMD (premenopause: 1146.8 [1138.9,1154.6] vs. postmenopause: 1136.1 [1130.1,1142.0] mg/cm 3; p-trend = 0.028) and cortical thickness (premenopause: 2.01 [1.95,2.06] vs. postmenopause: 1.93 [1.89,1.98] mm; p-trend = 0.036). After stratification by HIV status a similar patten was observed in women with HIV (cortical vBMD premenopause: 1152.9 [1128.5,1177.2] mg/cm 3 vs. postmenopause: 1123.6 [1106.0,1141.2] mg/cm 3, p-trend = 0.048). Total CSA varied little by menopause or HIV status at either radius sites; few differences were found at the tibia. CONCLUSION: In black South African women, menopause is associated with lower bone density and strength at the distal radius, a common site of osteoporotic fracture, in addition to lower cortical density and thickness at the proximal radius. Although the sample size was small, following stratification by HIV, women living with HIV had evidence of lower cortical density across menopause stages, unlike those without HIV. These findings raise concern for the incidence of Colles' fractures in postmenopausal women in South Africa; longitudinal studies of fracture incidence and implications of living with HIV are required.

Fragility fractures are painful, debilitating, often life-changing and accounted for an estimated 2.4% of pre-pandemic health care spending in the UK. Those who are older, frail and multimorbid have the highest fracture risk and therefore the most to gain from anti-osteoporosis treatments to reduce this risk. Currently, an unacceptable treatment gap exists between those eligible for and those who receive treatment. This commentary discusses the major changes to the new, National Institute for Health and Care Excellence accredited, UK National Osteoporosis Guideline Group (NOGG) guidance (published March 2022) most relevant to the management of older people’s bone health. Changes include intervention thresholds; using fracture probabilities from FRAX; for patients too frail to undergo DXA; greater emphasis on vertebral fracture detection and the use of intravenous zoledronate as a first-line anti-osteoporosis therapy; the new concept of ‘very high fracture risk’ which should prompt consideration of use of parenteral anti-osteoporosis therapy; new guidance regarding anabolic treatment options; concerns regarding denosumab cessation; and the urgent need to get patients with a fragility fracture onto treatment to reduce re-fracture risk with follow-up to check tolerance and ensure adherence.

IntroductionHip fractures are devastating injuries which incur high healthcare costs. Despite national standards and guidelines, there is substantial variation in hospital delivery of hip fracture care and in patient outcomes. This study aimed to understand organisational processes that facilitate successful delivery of hip fracture services.Methods Forty qualitative interviews were conducted with healthcare professionals involved in delivering hip fracture care at four English hospitals. Interview data were supplemented with documentary analysis of 23 anonymised British Orthopaedic Association hospital-initiated peer-review reports of services. Data were analysed thematically, with themes transposed onto key components of the care pathway. ResultsWe identified multiple aspects of service organisation that facilitated good care delivery. At admission, standardisation of training in nerve block administration impacted care delivery. During hospital stays, service delivery was improved by integrated, shared-care between orthopaedics and orthogeriatrics, and by strategies to improve trauma list efficiency. Adequately staffed orthogeriatric services and the ‘right’ skills and seniority mix were important to holistic care provision. Placing patients on designated hip fracture wards concentrated staff expertise. Collaborative working was achieved through multi-disciplinary team (MDT) meetings between key staff, protocols and care pathways that defined roles and responsibilities, MDT documentation, ‘joined-up’ IT systems within hospitals and with primary care, and shared working spaces such as shared offices and on wards. Trauma and hip fracture coordinators organised care processes and provided a valuable central point of contact within teams. Nominated leads, representing diverse specialties, worked together in MDT planning meetings to develop joint protocols, establish audit priorities, and agree shared goals. Routine, comprehensive monitoring and evaluation of service delivery, with findings shared throughout the MDT, was beneficial. ConclusionsOur study has characterised potentially modifiable elements of successful hip fracture service delivery. Findings are intended to help services overcome organisational barriers towards delivery of high-quality hip fracture services.

IntroductionOlder adults who sustain a hip fracture require complex multidisciplinary care, which can challenge organisational structures within hospitals. Despite standards and guidelines, substantial variation remains in hip fracture care delivery across the UK. We aimed to determine which hospital-level organisational factors predict adverse patient outcomes in the post injury period.Methods A cohort of 178,757 patients aged 60+ years in England and Wales (2016-19) who sustained a hip fracture was examined. Patient-level Hospital Episodes Statistics, National Hip Fracture Database, and mortality data were linked to metrics from 18 hospital-level organisational audits/reports/series. Multilevel models determined the organisational factors, independent of patient case-mix, associated with three patient outcomes: length of hospital stay (LOS), 30-day all-cause mortality, and emergency 30-day readmission. ResultsOverall LOS was mean 21 days (standard deviation, 20); 13,126 (7.3%) died within 30-days; and 25,239 (15.3%) were readmitted. 25 organisational factors independently predicted LOS: for example, a hospital’s ability to promptly mobilise ≥90% of patients was associated with a 2-day (95%CI:1.3-2.7) shorter LOS, and hospitals where all patients received orthogeriatric assessment within 72 hours of admission had mean 1.5-day (95%CI:0.6-2.3) shorter LOS. Ten organisational factors independently predicted 30-day mortality: providing prompt surgery (≤36 hours from admission) to >80% patients was associated with the same 10% reduction in mortality (95%CI:4-15%), as was discussion of “patient experience” feedback at clinical governance meetings (95%CI:5-15%). Nine organisational factors independently predicted readmission: knowledge of time from discharge to start of community therapy was associated with 17% (95%CI:9-24%) lower readmission rates. Organisational delivery of clinical governance, surgery, and physiotherapy were associated with all outcomes.ConclusionsMultiple, potentially modifiable, organisational factors are associated with important patient outcomes post-hip fracture. These factors, if causal, indicate auditable components of hospital care where interventions can be targeted to reduce variability in hip fracture care delivery, to improve patient outcomes.

Acknowledgements: NOGG are grateful to our external peer reviewers, stakeholders, and the Committee of Scientific Advisors of the International Osteoporosis Foundation and by the European Society for the Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases for their endorsement of this manuscript., UNLABELLED: The National Osteoporosis Guideline Group (NOGG) has revised the UK guideline for the assessment and management of osteoporosis and the prevention of fragility fractures in postmenopausal women, and men age 50 years and older. Accredited by NICE, this guideline is relevant for all healthcare professionals involved in osteoporosis management. INTRODUCTION: The UK National Osteoporosis Guideline Group (NOGG) first produced a guideline on the prevention and treatment of osteoporosis in 2008, with updates in 2013 and 2017. This paper presents a major update of the guideline, the scope of which is to review the assessment and management of osteoporosis and the prevention of fragility fractures in postmenopausal women, and men age 50 years and older. METHODS: Where available, systematic reviews, meta-analyses and randomised controlled trials were used to provide the evidence base. Conclusions and recommendations were systematically graded according to the strength of the available evidence. RESULTS: Review of the evidence and recommendations are provided for the diagnosis of osteoporosis, fracture-risk assessment and intervention thresholds, management of vertebral fractures, non-pharmacological and pharmacological treatments, including duration and monitoring of anti-resorptive therapy, glucocorticoid-induced osteoporosis, and models of care for fracture prevention. Recommendations are made for training; service leads and commissioners of healthcare; and for review criteria for audit and quality improvement. CONCLUSION: The guideline, which has received accreditation from the National Institute of Health and Care Excellence (NICE), provides a comprehensive overview of the assessment and management of osteoporosis for all healthcare professionals involved in its management. This position paper has been endorsed by the International Osteoporosis Foundation and by the European Society for the Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases.

A full list of authors and affiliations appears on page 5 of this article., The extent to which low-frequency (minor allele frequency (MAF) between 1-5%) and rare (MAF ≤ 1%) variants contribute to complex traits and disease in the general population is mainly unknown. Bone mineral density (BMD) is highly heritable, a major predictor of osteoporotic fractures, and has been previously associated with common genetic variants, as well as rare, population-specific, coding variants. Here we identify novel non-coding genetic variants with large effects on BMD (ntotal = 53,236) and fracture (ntotal = 508,253) in individuals of European ancestry from the general population. Associations for BMD were derived from whole-genome sequencing (n = 2,882 from UK10K (ref. 10); a population-based genome sequencing consortium), whole-exome sequencing (n = 3,549), deep imputation of genotyped samples using a combined UK10K/1000 Genomes reference panel (n = 26,534), and de novo replication genotyping (n = 20,271). We identified a low-frequency non-coding variant near a novel locus, EN1, with an effect size fourfold larger than the mean of previously reported common variants for lumbar spine BMD (rs11692564(T), MAF = 1.6%, replication effect size = +0.20 s.d., Pmeta = 2 × 10-14), which was also associated with a decreased risk of fracture (odds ratio = 0.85; P = 2 × 10-11; ncases = 98,742 and ncontrols = 409,511). Using an En1cre/flox mouse model, we observed that conditional loss of En1 results in low bone mass, probably as a consequence of high bone turnover. We also identified a novel low-frequency non-coding variant with large effects on BMD near WNT16 (rs148771817(T), MAF = 1.2%, replication effect size = +0.41 s.d., Pmeta = 1 × 10-11). In general, there was an excess of association signals arising from deleterious coding and conserved non-coding variants. These findings provide evidence that low-frequency non-coding variants have large effects on BMD and fracture, thereby providing rationale for whole-genome sequencing and improved imputation reference panels to study the genetic architecture of complex traits and disease in the general population., peer-reviewed

Women in sub-Saharan Africa report multiple impacts of menopause on daily life and have requested further information to support themselves. This study co-produced contextually relevant resources—booklets and poster—about menopause with women in Zimbabwe and South Africa. The study was conducted in four stages: interviews with women about the menopause; the development of prototype information resources; workshops with women to discuss country-specific resources; and the refinement of resources. During the interviews, women explained that they had not received or accessed much information about the menopause and thought the physical and psychological issues associated with the menopause had to be “endured”. Prototype information resources comprised booklets and a poster with contextually relevant images and information. Workshop participants suggested several changes, including the addition of more diverse images and further information about treatments. The resources were refined, translated into several African languages, and endorsed by the Ministry of Health in Zimbabwe and the South African Menopause Society in South Africa. Women will be able to access resources through healthcare clinics, community groups and churches. Working with women and other stakeholders enabled a development that was cognisant of experiences and needs. Work is now needed to improve access to treatments and support for menopause to reduce health inequities.

Over 80 heat treatment experiments have been made on samples of chloride-contaminated plutonium dioxide retrieved from two packages in storage at Sellafield. These packages dated from 1974 and 1980 and were produced in a batch process by conversion of plutonium oxalate in a furnace at around 550 °C. The storage package contained a poly(vinyl chloride) (PVC) bag between the screw top inner and outer metal cans. Degradation of the PVC has led to adsorption of hydrogen chloride together with other atmospheric gases onto the PuO2 surface. Analysis by caustic leaching and ion chromatography gave chloride contents of 2000 to >5000 ppm Cl (i.e., μgCl g-1 of the original sample). Although there are some subtle differences, in general, there is surprisingly good agreement in results from heat treatment experiments for all the samples from both cans. Mass loss on heating (LOH) plateaus at nearly 3 wt % above 700 °C, although samples that were long stored under an air atmosphere or preexposed to 95% relative humidity atmospheres, gave higher LOH up to â4 wt %. The majority of the mass loss is due to adsorbed water and other atmospheric gases rather than chloride. Heating volatilizes chloride only above â400 °C implying that simple physisorption of HCl is not the main cause of contamination. Interestingly, above 700 °C, >100% of the initial leachable chloride can be volatilized. Surface (leachable) chloride decreases quickly with heat treatment temperatures up to â600 °C but only slowly above this temperature. Storage in air atmosphere post-heat treatment apparently leads to a reequilibration as leachable chloride increases. The presence of a "nonleachable" form of chloride was thus inferred and subsequently confirmed in PuO2 samples (pre- A nd post-heat treatment) that were fully dissolved and analyzed for the total chloride inventory. Reheating samples in either air or argon at temperatures up to the first heat treatment temperature did not volatilize significant amounts of additional chloride. With regard to a thermal stabilization process, heat treatment in flowing air at 800 °C with cooling and packaging under dry argon appears optimal, particularly, if thinner powder beds can be maintained. From electron microscopy, heat treatment appeared to have the most effect on degrading the square platelet particles compared to those with the trapezoidal morphology.

Genetic disorders of the skeleton encompass a diverse group of bone diseases differing in clinical characteristics, severity, incidence and molecular etiology. Of particular interest are the monogenic rare bone mass disorders, with the underlying genetic defect contributing to either low or high bone mass phenotype. Extensive, deep phenotyping coupled with high-throughput, cost-effective genotyping is crucial in the characterization and diagnosis of affected individuals. Massive parallel sequencing efforts have been instrumental in the discovery of novel causal genes that merit functional validation using in vitro and ex vivo cell-based techniques, and in vivo models, mainly mice and zebrafish. These translational models also serve as an excellent platform for therapeutic discovery, bridging the gap between basic science research and the clinic. Altogether, genetic studies of monogenic rare bone mass disorders have broadened our knowledge on molecular signaling pathways coordinating bone development and metabolism, disease inheritance patterns, development of new and improved bone biomarkers, and identification of novel drug targets. In this comprehensive review we describe approaches to further enhance the innovative processes taking discoveries from clinic to bench, and then back to clinic in rare bone mass disorders. We highlight the importance of cross laboratory collaboration to perform functional validation in multiple model systems after identification of a novel disease gene. We describe the monogenic forms of rare low and high rare bone mass disorders known to date, provide a roadmap to unravel the genetic determinants of monogenic rare bone mass disorders using proper phenotyping and genotyping methods, and describe different genetic validation approaches paving the way for future treatments., peer-reviewed

Background: Poor linear growth and pubertal delay, both common in children with HIV (CWH) in sub-Saharan Africa, may affect adolescent bone accrual and future fragility fracture risk. We investigated the association of HIV with size-adjusted bone density in peri-pubertal children in Zimbabwe. Methods: CWH aged 8-16 years taking ART for ≥2 years from public-sector HIV clinics in Harare, and HIV-uninfected children from schools in the same catchment area, were recruited into a cross-sectional study. Sociodemographic, clinical and anthropometric data were collected. Outcomes were dual-energy X-ray absorptiometry (DXA) measured total-body less-head bone mineral content-for-lean mass adjusted for height (TBLH-BMCLBM) and lumbar spine bone mineral apparent density (LS-BMAD). Linear regression models using multiple imputation for missing data, assessed relationships between risk factors and DXA measures by HIV status, and interaction by sex and pubertal (Tanner) stage. Findings: We recruited 303 CWH and 306 without HIV, mean (SD) age 12.5 (2.5) years and 50% female. Mean ART duration was 7.9 (2.6) years; for 34% ART included tenofovir disproxil fumarate (TDF). The prevalence of low TBLH-BMCLBM and LS-BMAD (Z-Score

The discovery that sclerostin is the defective protein underlying the rare heritable bone mass disorder, sclerosteosis, ultimately led to development of anti-sclerostin antibodies as a new treatment for osteoporosis. In the era of large scale GWAS, many additional genetic signals associated with bone mass and related traits have since been reported. However, how best to interrogate these signals in order to identify the underlying gene responsible for these genetic associations, a prerequisite for identifying drug targets for further treatments, remains a challenge. The resources available for supporting functional genomics research continues to expand, exemplified by “multi-omics” database resources, with improved availability of datasets derived from bone tissues. These databases provide information about potential molecular mediators such as mRNA expression, protein expression, and DNA methylation levels, which can be interrogated to map genetic signals to specific genes based on identification of causal pathways between the genetic signal and the phenotype being studied. Functional evaluation of potential causative genes has been facilitated by characterization of the “osteocyte signature”, by broad phenotyping of knockout mice with deletions of over 7,000 genes, in which more detailed skeletal phenotyping is currently being undertaken, and by development of zebrafish as a highly efficient additional in vivo model for functional studies of the skeleton. Looking to the future, this expanding repertoire of tools offers the hope of accurately defining the major genetic signals which contribute to osteoporosis. This may in turn lead to the identification of additional therapeutic targets, and ultimately new treatments for osteoporosis.