Long-read proteogenomics to connect disease-associated sQTLs to the protein isoform effectors of disease.

A major fraction of loci identified by genome-wide association studies (GWASs) mediate alternative splicing, but mechanistic interpretation is hindered by the technical limitations of short-read RNA sequencing (RNA-seq), which cannot directly link splicing events to full-length protein isoforms. Long-read RNA-seq represents a powerful tool to characterize transcript isoforms, and recently, infer protein isoform existence. Here, we present an approach that integrates information from GWASs, splicing quantitative trait loci (sQTLs), and PacBio long-read RNA-seq in a disease-relevant model to infer the effects of sQTLs on the ultimate protein isoform products they encode. We demonstrate the utility of our approach using bone mineral density (BMD) GWAS data. We identified 1,863 sQTLs from the Genotype-Tissue Expression (GTEx) project in 732 protein-coding genes that colocalized with BMD associations (H4PP ≥ 0.75). We generated PacBio Iso-Seq data (N = ∼22 million full-length reads) on human osteoblasts, identifying 68,326 protein-coding isoforms, of which 17,375 (25%) were unannotated. By casting the sQTLs onto protein isoforms, we connected 809 sQTLs to 2,029 protein isoforms from 441 genes expressed in osteoblasts. Overall, we found that 74 sQTLs influenced isoforms likely impacted by nonsense-mediated decay and 190 that potentially resulted in the expression of unannotated protein isoforms. Finally, we functionally validated colocalizing sQTLs in TPM2, in which siRNA-mediated knockdown in osteoblasts showed two TPM2 isoforms with opposing effects on mineralization but exhibited no effect upon knockdown of the entire gene. Our approach should be to generalize across diverse clinical traits and to provide insights into protein isoform activities modulated by GWAS loci.

The impact of anorexia nervosa and BMI polygenic risk on childhood growth: A 20-year longitudinal population-based study.

Growth deviating from the norm during childhood has been associated with anorexia nervosa (AN) and obesity later in life. In this study, we examined whether polygenic scores (PGSs) for AN and BMI are associated with growth trajectories spanning the first two decades of life. AN PGSs and BMI PGSs were calculated for participants of the Avon Longitudinal Study of Parents and Children (ALSPAC; n = 8,654). Using generalized (mixed) linear models, we associated PGSs with trajectories of weight, height, body mass index (BMI), fat mass index (FMI), lean mass index (LMI), and bone mineral density (BMD). Female participants with AN PGSs one standard deviation (SD) higher had, on average, 0.004% slower growth in BMI between the ages 6.5 and 24 years and a 0.4% slower gain in BMD between the ages 10 and 24 years. Higher BMI PGSs were associated with faster growth for BMI, FMI, LMI, BMD, and weight trajectories in both sexes throughout childhood. Female participants with both a high AN PGS and a low BMI PGS showed slower growth compared to those with both a low AN PGS and a low BMI PGS. We conclude that AN PGSs and BMI PGSs have detectable sex-specific effects on growth trajectories. Female participants with a high AN PGS and low BMI PGS likely constitute a high-risk group for AN, as their growth was slower compared to their peers with high PGSs on both traits. Further research is needed to better understand how the AN PGS and the BMI PGS co-influence growth during childhood and whether a high BMI PGS can mitigate the effects of a high AN PGS.

Evolutionary and functional analyses of LRP5 in archaic and extant modern humans.

BACKGROUND: The human lineage has undergone a postcranial skeleton gracilization (i.e. lower bone mass and strength relative to body size) compared to other primates and archaic populations such as the Neanderthals. This gracilization has been traditionally explained by differences in the mechanical load that our ancestors exercised. However, there is growing evidence that gracilization could also be genetically influenced. RESULTS: We have analyzed the LRP5 gene, which is known to be associated with high bone mineral density conditions, from an evolutionary and functional point of view. Taking advantage of the published genomes of archaic Homo populations, our results suggest that this gene has a complex evolutionary history both between archaic and living humans and within living human populations. In particular, we identified the presence of different selective pressures in archaics and extant modern humans, as well as evidence of positive selection in the African and South East Asian populations from the 1000 Genomes Project. Furthermore, we observed a very limited evidence of archaic introgression in this gene (only at three haplotypes of East Asian ancestry out of the 1000 Genomes), compatible with a general erasing of the fingerprint of archaic introgression due to functional differences in archaics compared to extant modern humans. In agreement with this hypothesis, we observed private mutations in the archaic genomes that we experimentally validated as putatively increasing bone mineral density. In particular, four of five archaic missense mutations affecting the first ß-propeller of LRP5 displayed enhanced Wnt pathway activation, of which two also displayed reduced negative regulation. CONCLUSIONS: In summary, these data suggest a genetic component contributing to the understanding of skeletal differences between extant modern humans and archaic Homo populations.

Causal effects of osteoporosis on structural changes in specific brain regions: a Mendelian randomization study.

Observational studies have reported that osteoporosis is associated with cortical changes in the brain. However, the inherent limitations of observational studies pose challenges in eliminating confounding factors and establishing causal relationships. And previous observational studies have not reported changes in specific brain regions. By employing Mendelian randomization, we have been able to infer a causal relationship between osteoporosis and a reduction in the surficial area (SA) of the brain cortical. This effect is partially mediated by vascular calcification. We found that osteoporosis significantly decreased the SA of global brain cortical (ß = -1587.62 mm2, 95%CI: -2645.94 mm2 to -529.32 mm2, P = 0.003) as well as the paracentral gyrus without global weighted (ß = - 19.42 mm2, 95%CI: -28.90 mm2 to -9.95 mm2, P = 5.85 × 10-5). Furthermore, we estimated that 42.25% and 47.21% of the aforementioned effects are mediated through vascular calcification, respectively. Osteoporosis leads to a reduction in the SA of the brain cortical, suggesting the presence of the bone-brain axis. Vascular calcification plays a role in mediating this process to a certain extent. These findings establish a theoretical foundation for further investigations into the intricate interplay between bone, blood vessels, and the brain.

Epigenetic Aging and Musculoskeletal Outcomes in a Cohort of Women Living With HIV.

BACKGROUND: The relationship between accelerated epigenetic aging and musculoskeletal outcomes in women with HIV (WWH) has not been studied. METHODS: We measured DNA methylation age using the Infinium MethylationEPIC BeadChip in a cohort from the Women's Interagency HIV Study (n = 190) with measures of bone mineral density (BMD) and physical function. We estimated 6 biomarkers of epigenetic aging-epigenetic age acceleration (EAA), extrinsic EAA, intrinsic EAA, GrimAge, PhenoAge, and DNA methylation-estimated telomere length-and evaluated associations of epigenetic aging measures with BMD and physical function. We also performed epigenome-wide association studies to examine associations of DNA methylation signatures with BMD and physical function. RESULTS: This study included 118 WWH (mean age, 49.7 years; 69% Black) and 72 without HIV (mean age, 48.9 years; 69% Black). WWH had higher EAA (mean ± SD, 1.44 ± 5.36 vs -1.88 ± 5.07; P < .001) and lower DNA methylation-estimated telomere length (7.13 ± 0.31 vs 7.34 ± 0.23, P < .001) than women without HIV. There were no significant associations between accelerated epigenetic aging and BMD. Rather, measures of accelerated epigenetic aging were associated with lower physical function. CONCLUSIONS: Accelerated epigenetic aging was observed in WWH as compared with women without HIV and was associated with lower physical function in both groups.

Metabolic, cardiac, and bone health testing in patients with prostate cancer on androgen-deprivation therapy: A population-based assessment of adherence to therapeutic monitoring guidelines.

BACKGROUND: Androgen-deprivation therapy (ADT) remains a cornerstone in treatment for patients with advanced prostate cancer. ADT is associated with several adverse effects, including osteoporosis, metabolic syndrome, and cardiovascular events, leading to guidelines recommending routine testing to monitor for these toxicities. There is a lack of data assessing adherence to these recommendations. METHODS: The authors conducted a retrospective cohort study using administrative data from Ontario, Canada between 2008 and 2021. They identified all older men (aged 65 years and older) who received ADT for prostate cancer using comprehensive provincial health databases. The primary outcomes were the use of testing for lipids, dysglycemia (glucose), bone health serum, and bone density between 6 weeks before and 1 year after the initiation of ADT. RESULTS: In total, 29,097 patients were examined, of whom 52.8% were prescribed ADT by urologists, 37.9% were prescribed ADT by radiation oncologists, 2.8% were prescribed ADT by medical oncologists, and 2.4% were prescribed ADT by other physicians. Adherence to guidelines was low: only 21.3% of patients received a bone density scan, 41.2% underwent bone health-related serum tests, 51.3% completed a lipid profile, and 65.9% underwent dysglycemia testing within 1 year of diagnosis. Overall, only 11.9% of patients received all of the recommended investigations. Adherence to testing did not appear to improve over time (2008-2021) or with guideline publication. Patient (age) and physician (specialty) factors had important associations with adherence to testing. CONCLUSIONS: Most patients receiving ADT for prostate cancer do not receive recommended testing to monitor for treatment-related toxicity. Further study is required to address barriers to therapeutic monitoring of men on ADT and to reduce treatment-associated adverse events.

Effects of LP533401 on vascular and bone calcification in hyperlipidemic mice.

Peripheral serotonin levels are associated with cardiovascular disease risk. We previously found that serum serotonin levels are higher in hyperlipidemic mice than wild-type mice. Evidence also suggests that serotonin regulates biomineralization, in that serotonin treatment augments TNF-a-induced matrix calcification of aortic valve interstitial cells and that a selective inhibitor of peripheral serotonin, LP533401, rescues bone loss induced by ovariectomy in mice. Thus, in the present study, we examined the effects of LP533401 on both skeletal bone mineral density (BMD) and aortic calcification in both young and older hyperlipidemic mice susceptible to calcific atherosclerosis and bone loss. By serial in vivo microCT imaging, we assessed BMD and aortic calcification of Apoe-/- mice fed an atherogenic (high cholesterol) diet alone or mixed with LP533401. Results show that in the young mice, LP533401 blunted skeletal bone loss in lumbar vertebrae but not in femurs. LP533401 also blunted the initial development of aortic calcification but not its progression. Echocardiographic analysis showed that LP533401 blunted both hyperlipidemia-induced cardiac hypertrophy and left ventricular dysfunction. In the older mice, LP533401 increased the BMD of lumbar vertebrae but not of femurs. The aortic calcification progressed in both controls and LP533401-treated mice, but, at post-treatment, LP533401-treated mice had significantly less aortic calcification than the controls. These findings suggest that LP533401 mitigates adverse effects of hyperlipidemia on skeletal and vascular tissues in site- and stage-dependent manners.

A prospective study of vitamin D, proinflammatory cytokines, and risk of fragility fractures in women on aromatase inhibitors for breast cancer.

BACKGROUND: Vitamin D is critical to bone health by regulating intestinal absorption of calcium, whereas proinflammatory cytokines, including IL-1, IL-6, IL-12, and TNF-α, are known to increase bone resorption. We hypothesized that vitamin D and these cytokines at the time of breast cancer diagnosis were predictive for fragility fractures in women receiving aromatase inhibitors (AIs). METHODS: In a prospective cohort of 1,709 breast cancer patients treated with AIs, we measured the levels of 25-hydroxyvitamin D (25OHD), IL-1ß, IL-6, IL-12, and TNF-α from baseline blood samples. The associations of these biomarkers were analyzed with bone turnover markers (BALP and TRACP), bone regulatory markers (OPG and RANKL), bone mineral density (BMD) close to cancer diagnosis, and risk of fragility fractures during a median of 7.5 years of follow up. RESULTS: Compared to patients with vitamin D deficiency, patients with sufficient levels had higher bone turnover, lower BMD, and higher fracture risk; the latter became non-significant after controlling for covariates including BMD and no longer existed when patients taking vitamin D supplement or bisphosphonates or with history of fracture or osteoporosis were excluded. There was a non-significant trend of higher levels of IL-1ß and TNF-α associated with higher risk of fracture (highest vs. lowest tertile, IL-1ß: adjusted HR=1.37, 95% CI=0.94-1.99; TNF-α: adjusted HR=1.38, 95% CI=0.96-1.98). CONCLUSIONS: Our results do not support proinflammatory cytokines or vitamin D levels as predictors for risk of fragility fractures in women receiving AIs for breast cancer.

Causal relationships between anthropometric traits, bone mineral density, osteoarthritis and spinal stenosis: A Mendelian randomisation investigation.

OBJECTIVE: Spinal stenosis is a common condition among older individuals, with significant morbidity attached. Little is known about its risk factors but degenerative conditions, such as osteoarthritis (OA) have been identified for their mechanistic role. This study aims to explore causal relationships between anthropometric risk factors, OA, and spinal stenosis using Mendelian randomisation (MR) techniques. DESIGN: We applied two-sample MR to investigate the causal relationships between genetic liability for select risk factors and spinal stenosis. Next, we examined the genetic relationship between OA and spinal stenosis with linkage disequilibrium score regression and Causal Analysis Using Summary Effect estimates MR method. Finally, we used multivariable MR (MVMR) to explore whether OA and body mass index (BMI) mediate the causal pathways identified. RESULTS: Our analysis revealed strong evidence for the effect of higher BMI (odds ratio [OR] = 1.54, 95%CI: 1.41-1.69, p-value = 2.7 × 10-21), waist (OR = 1.43, 95%CI: 1.15-1.79, p-value = 1.5 × 10-3) and hip (OR = 1.50, 95%CI: 1.27-1.78, p-value = 3.3 × 10-6) circumference on spinal stenosis. Strong evidence of causality was also observed for higher bone mineral density (BMD): total body (OR = 1.21, 95%CI: 1.12-1.29, p-value = 1.6 × 10-7), femoral neck (OR = 1.35, 95%CI: 1.09-1.37, p-value = 7.5×10-7), and lumbar spine (OR = 1.38, 95%CI: 1.25-1.52, p-value = 4.4 × 10-11). We detected high genetic correlations between spinal stenosis and OA (rg range: 0.47-0.66), with Causal Analysis Using Summary Effect estimates results supporting a causal effect of OA on spinal stenosis (ORallOA = 1.6, 95%CI: 1.41-1.79). Direct effects of BMI, BMD on spinal stenosis remained after adjusting for OA in the MVMR. CONCLUSIONS: Genetic susceptibility to anthropometric risk factors, particularly higher BMI and BMD can increase the risk of spinal stenosis, independent of OA status. These results may inform preventative strategies and treatments.

Increased prevalence of osteopenia and osteoporosis in systemic sclerosis patients, including in men and young women- a case-control study.

OBJECTIVES: To investigate bone mineral density (BMD), osteoporosis prevalence and systemic sclerosis (SSc) specific associations of BMD in SSc patients compared with background population. METHODS: In total, 211 SSc patients (182 women, 29 men; mean age 61.3 and 62.2 respectively) and 505 age and sex matched controls from the same geographic area participated. BMD and T-score at total hip and lumbar spine was measured by Dual-energy X-ray absorptiometry. Osteopenia was defined as T-score -1.0 to -2.5; osteoporosis as T-score ≤-2.5. Associates of low BMD were identified by multiple regression analysis. RESULTS: Women with SSc had lower BMD for total hip (p< 0.001) and spine (p= 0.011), equivalent to ΔT-score -0.56 and -0.35 compared with controls. Osteopenia was present in 51.6% and 16.5% had osteoporosis (p= 0.001, compared with controls). Already in women below age 45, differences in hip BMD were apparent (ΔT-score -0.93, p= 0.005). In addition to expected risk factors for osteoporosis (older age, lower BMI and menopause), finger ulcers (p= 0.009) and diffuse skin involvement (p= 0.027) were associated with lower hip BMD in women. In men with SSc, more than half displayed osteopenia or osteoporosis and had numerically lower hip BMD than their age matched counterparts. CONCLUSION: SSc patients, including men and younger women, have lower BMD than the background population. Finger ulcers and diffuse skin involvement, in addition to older age, lower BMI and being post-menopausal, are associated with lower BMD in women. The data emphasizes the importance of performing bone health assessment of all SSc patients, including men and young subjects.

Impact of osteoporosis on overall survival following endovascular repair for abdominal aortic aneurysms.

OBJECTIVE: To evaluate the impact of osteoporosis on overall survival following endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms (AAAs). METHODS: This was a retrospective, single-center cohort study on 172 patients who had undergone primary EVAR for AAA between 2016 and 2018. Bone mineral density (BMD) was assessed by measuring the Hounsfield units (HUs) of the 11th thoracic vertebra on preoperative computed tomography; a BMD value of <110 HU was considered osteoporosis. All patients were divided into those with osteoporosis and those without osteoporosis, and long-term outcomes were compared. In addition, hazard ratios of each variable for all-cause mortality were evaluated using univariate and multivariate analysis. RESULTS: All 172 patients were divided into two groups: 72 patients (41.9%) with osteoporosis and 100 patients (58.1%) without osteoporosis. The mean age was older and the mean BMD was lower in patients with osteoporosis than patients without osteoporosis (mean, 79.2 ± 7.2 years vs 75.0 ± 8.7 years, respectively; P < .05; 78.1 ± 26.7 HU vs 155.1 ± 36.3 HU, respectively; P < .05). During the median follow-up period of 68 months, overall survival was significantly lower in patients with osteoporosis than patients without osteoporosis (osteoporosis: 63.9% and 36.7% at 5 years and 7 years; nonosteoporosis: 83.8% and 74.6% at 5 years and 7 years, respectively; log-rank P < .05); freedom from aneurysm-related mortality did not differ significantly between groups (osteoporosis: 94.3% and 89.0% at 5 years and 7 years; nonosteoporosis: 100.0% and 96.7% at 5 years and 7 years, respectively; log-rank P = .078). In a multivariate analysis for overall survival after EVAR, coexistence of osteoporosis was found to be an independent risk factor for all-cause mortality (hazard ratio, 1.76; 95% confidence interval, 1.01-3.06; P < .05), as well as variables including age, statin use, sarcopenia, and aneurysm diameter. CONCLUSIONS: Patients with osteoporosis showed a higher all-cause mortality after EVAR than patients without osteoporosis. We believe that comorbidity of osteoporosis may be useful in estimating the life expectancy of patients with AAA.

Causal relationship between circulating levels of cytokines and bone mineral density: A mendelian randomization study.

BACKGROUND: Numerous studies have shown that various cytokines are important factors affecting bone mineral density (BMD), but the causality between the two remains uncertain. METHODS: Genetic variants associated with 41 circulating cytokines from a genome-wide association study (GWAS) in 8,293 Finns were used as instrumental variables (IVs) for a two-sample Mendelian randomization (MR) analysis. Inverse variance weighting (IVW) was employed as the primary method to investigate whether the 41 cytokines were causally associated with BMD at five different sites [total body bone mineral density (TB-BMD), heel bone mineral density (HE-BMD), forearm bone mineral density (FA-BMD), femoral neck bone mineral density (FN-BMD), and lumbar spine bone mineral density (LS-BMD)]. Weighted median and MR-Egger were chosen to further confirm the robustness of the results. We performed MR pleiotropy residual sum and outlier test (MR-PRESSO), MR-Egger regression, and Cochran's Q test to detect pleiotropy and sensitivity testing. RESULTS: After Bonferroni correction, two circulating cytokines had a strong causality with BMD at corresponding sites. Genetically predicted circulating hepatocyte growth factor (HGF) levels and HE-BMD were negatively correlated [ß (95 % CI) -0.035(-0.055, -0.016), P=0.00038]. Circulating macrophage inflammatory protein-1α (MIP-1α) levels and TB-BMD were negatively correlated [ß(95 %CI): -0.058(-0.092, -0.024), P=0.00074]. Weighted median and MR-Egger results were in line with the IVW results. We also found suggestive causal relationship (IVW P<0.05) between seven circulating cytokines and BMD at corresponding sites. No significant pleiotropy or heterogeneity was observed in our study. CONCLUSION: Our MR analyses indicated a causal effect between two circulating cytokines and BMD at corresponding sites (HGF and HE-BMD, MIP-1α and TB-BMD), along with suggestive evidence of a potential causality between seven cytokines and BMD at the corresponding sites. These findings would provide insights into the prevention and treatment of osteoporosis, especially immunoporosis.

The effect of starting metformin on bone mineral density among women with type 2 diabetes in the Study of Women's Health Across the Nation (SWAN).

We examined longitudinal changes in BMD among women in the mid-life starting metformin. Study subjects were 57 years old (mean), and 36% were White. Women initiating metformin were similar to noninitiators. During the 3-year follow-up, BMD loss at all anatomic areas was similar between groups and in subgroups including baseline fasting blood glucose. PURPOSE/INTRODUCTION: Women with type 2 diabetes have higher bone mineral density (BMD), experience slower BMD loss, but have increased fracture risk. Data regarding the effect of metformin on BMD remain discordant. We examined longitudinal changes in BMD among women in the mid-life starting metformin. METHODS: Participants in the Study of Women's Health Across the Nation (SWAN), a diverse community-based US cohort, with BMD measurements were evaluated. Propensity score matching helped balance baseline characteristics of metformin initiators versus noninitiators. Mixed model regression tested the change in BMD between groups. RESULTS: Subjects (n = 248) were 57.4 years old (mean), and 35.9% were White. Women initiating metformin (n = 124) were similar to noninitiators (n = 124) in age and race/ethnicity. During the median 3-year follow-up, BMD loss at all anatomic areas was similar between the metformin initiators and nonusers (all p > 0.3). Subgroup analyses including baseline fasting blood glucose showed no between-group differences. Initiation of metformin (vs. not) in peri-menopausal women was not associated with BMD changes. CONCLUSIONS: Women in the mid-life starting metformin had longitudinal changes in BMD very similar to other women not starting metformin.

The effect of romosozumab on bone mineral density depending on prior treatment: a prospective, multicentre cohort study in Switzerland.

This multicentre, prospective cohort study measured the effect of romosozumab for 12 months on bone mineral density, taking into account prior therapies. Prior antiresorptive therapy blunted the BMD response to romosozumab, and the duration was correlated with BMD changes at both the lumbar spine and total hip. INTRODUCTION: In Switzerland, romosozumab is administered to high-risk osteoporosis patients. Our study aimed to assess the effect of romosozumab on bone mineral density (BMD), taking into account prior therapies. METHODS: This multicentre, prospective cohort study measured the effect of romosozumab for 12 months in patients in a nationwide Swiss osteoporosis registry. BMD and bone turnover marker (P1NP and CTX) changes were measured and compared between pre-treated and treatment naïve patients. RESULTS: Ninety-nine patients (92 women and 7 men, median age 71 years [65, 76]) were enrolled from January 2021 to December 2023. Among them, 22 had no prior treatment before romosozumab, while 77 had previous therapy (including 23 with a history of prior teriparatide therapy), with a median duration of 6 years [4, 11] of cumulative antiresorptive treatment. Over 12 months, romosozumab led to BMD changes of 10.3% [7.5, 15.5] at the lumbar spine, 3.1% [1.1, 5.8] at the total hip and 3.1% [0.5, 5.3] at the femoral neck, indicating notable variability. Significantly lower BMD responses were observed in pre-treated patients, with the duration of prior antiresorptive therapy inversely associated with BMD increases at the lumbar spine and hip. Other predictors of BMD changes at the total hip included baseline T-scores at the hip, body mass index and baseline CTX level, while the BMD response at the lumbar spine was associated with the lumbar spine T-score at baseline, age and baseline CTX level. CONCLUSION: Prior antiresorptive therapy blunted the BMD response to romosozumab, and the duration was correlated with BMD changes at both the lumbar spine and total hip.

Isoflavone intervention and its impact on bone mineral density in postmenopausal women: a systematic review and meta-analysis of randomized controlled trials.

Due to estrogen deficiency, postmenopausal women may suffer from an imbalance in bone metabolism that leads to bone fractures. Isoflavones, a type of phytoestrogen, have been suggested to improve bone metabolism and increase bone mass. Therefore, isoflavones are increasingly recognized as a promising natural alternative to hormone replacement therapy for postmenopausal women who face a heightened risk of osteoporosis and are susceptible to bone fractures. PURPOSE: This study aimed to evaluate the efficacy of isoflavone interventions on bone mineral density (BMD) in postmenopausal women by means of systematic review and meta-analysis. METHODS: The electronic database searches were performed on PubMed, Embase, Scopus, and Cochrane Library databases, covering literature up to April 20, 2023. A random-effects model was used to obtain the main effect estimates, with a mean difference (MD) and its 95% confidence interval (CI) as the effect size summary. The risk of bias assessment was conducted using the Risk of Bias 2 (RoB2) tool. RESULTS: A total of 63 randomized controlled trials comparing isoflavone interventions (n = 4,754) and placebo (n = 4,272) were included. The results indicated that isoflavone interventions significantly improved BMD at the lumbar spine (MD = 0.0175 g/cm2; 95% CI, 0.0088 to 0.0263, P < 0.0001), femoral neck (MD = 0.0172 g/cm2; 95% CI, 0.0046 to 0.0298, P = 0.0073), and distal radius (MD = 0.0138 g/cm2; 95% CI, 0.0077 to 0.0198, P < 0.0001) in postmenopausal women. Subgroup analysis showed that the isoflavone intervention was effective for improving BMD when the duration was ≥ 12 months and when the intervention contained genistein of at least 50 mg/day. CONCLUSION: This systematic review and meta-analysis suggests that isoflavone interventions, especially those containing genistein of at least 50 mg/day, can effectively enhance BMD in postmenopausal women.

Bone density and fracture risk factors in ankylosing spondylitis: a meta-analysis.

We included 39 studies in our meta-analysis, finding that patients with ankylosing spondylitis (AS) exhibit decreased bone mineral density (BMD) and an elevated risk of fractures. Additionally, we analyzed the risk factors associated with fractures in these patients. INTRODUCTION: AS is a chronic inflammatory disease primarily affecting the spine and sacroiliac joints, with reduced BMD, osteoporosis, and fractures being common complications. This study aims to systematically consolidate and conduct a meta-analysis of existing research to comprehensively understand decreased bone mineral density, osteoporosis, and fracture risks at various anatomical sites in AS patients. The objective is to provide reliable information for the management of AS patients and to inform clinical decision making. METHODS: We conducted a thorough search in various databases including Embase, PubMed, Cochrane Library, and Web of Science. These studies focused on the risk of and risk factors for decreased BMD, osteopenia, osteoporosis, and fractures at different sites among AS patients such as the lumbar spine and femoral neck. The quality of eligible studies was evaluated. Sensitivity analysis was performed to assess the reliability of our analysis results and understand the effects of individual studies on the heterogeneity across studies. RESULTS: A total of 39 studies were included. Our meta-analysis results revealed significant differences between AS patients and healthy controls. AS patients had significantly lower BMDs at the femoral neck, hip, lumbar vertebra 2 (L2), lumbar vertebra 3 (L3), and lumbar vertebra 4 (L4), but higher BMDs at 1/3 distal radius and ultra distal radius. Risk factors for fractures among AS patients included old age, long course of disease, and low BMD at the lumbar spine. In contrast, factors such as erythrocyte sedimentation rate (ESR), the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score, gender, and body mass index (BMI) were not risk factors for fractures in AS patients. CONCLUSION: Our study highlights that BMD at the femoral neck is more effective for evaluating AS patients compared with the BMD at the lumbar spine. Additionally, the risk of osteoporosis and fractures in AS patients is higher in younger patients and those at the early stage of this disease.

Metformin treatment reduces the incidence of osteoporosis: a two-sample Mendelian randomized study.

It remains unclear whether the association between metformin and osteoporosis (OP) risk is causal. This two-sample Mendelian randomization (MR) study suggests a causal relationship between metformin treatment and a decrease in OP and fracture incidence, as well as an increase in bone mineral density (BMD) in the lumbar spine, femoral neck, and heel. Nonetheless, no significant causal effect is observed on forearm BMD. PURPOSE: We utilize a MR approach to investigate the association between metformin treatment and the risk of OP. METHODS: Metformin treatment was selected as exposures. Outcomes included OP; BMD at the forearm (FA), femoral neck (FN), and lumbar spine (LS); estimated heel bone mineral density (eBMD); and fracture. Summary statistics for exposures and outcomes were obtained from corresponding genome-wide association studies. Inverse variance-weighted (IVW) analysis was mainly applied; the weighted median (WM), penalized weighted median (PWM), maximum likelihood (ML), and MR-Egger regression (MR-Egger) method were also used to obtain robust estimates. A series of sensitivity analyses including Cochran's Q test, MR-Egger regression, leave-one-out analysis, and Mendelian randomization pleiotropy residual sum and outlier (MR-PRESSO) were used to detect pleiotropy or heterogeneity. RESULTS: In the main analysis, IVW estimates demonstrated that metformin treatment had a definite causal effect on the risk of OP (odds ratio (OR): 0.859, 95% CI: 0.774-0.953, P = 0.004), LS-BMD (OR: 1.063, 95% CI: 1.023-1.105, P = 0.002), FN-BMD (OR: 1.034, 95% CI: 1.000-1.069, P = 0.049), eBMD (OR: 1.035, 95% CI: 1.023-1.047, P ≤ 0.001), and fracture(OR: 0.958, 95% CI: 0.928-0.989, P = 0.008). However, it did not have an effect on FA-BMD(OR: 1.050, 95% CI: 0.969-1.138, P = 0.237). CONCLUSIONS: This study indicated that metformin treatment is significantly associated with a reduction in the risk of OP, fracture and higher LS-BMD, FN-BMD, and eBMD. However, there was no significant association with FA-BMD.

Semi-automatic proximal humeral trabecular bone density assessment tool: technique application and clinical validation.

PURPOSE: This study aimed to apply a newly developed semi-automatic phantom-less QCT (PL-QCT) to measure proximal humerus trabecular bone density based on chest CT and verify its accuracy and precision. METHODS: Subcutaneous fat of the shoulder joint and trapezius muscle were used as calibration references for PL-QCT BMD measurement. A self-developed algorithm based on a convolution map was utilized in PL-QCT for semi-automatic BMD measurements. CT values of ROIs used in PL-QCT measurements were directly used for phantom-based quantitative computed tomography (PB-QCT) BMD assessment. The study included 376 proximal humerus for comparison between PB-QCT and PL-QCT. Two sports medicine doctors measured the proximal humerus with PB-QCT and PL-QCT without knowing each other's results. Among them, 100 proximal humerus were included in the inter-operative and intra-operative BMD measurements for evaluating the repeatability and reproducibility of PL-QCT and PB-QCT. RESULTS: A total of 188 patients with 376 shoulders were involved in this study. The consistency analysis indicated that the average bias between proximal humerus BMDs measured by PB-QCT and PL-QCT was 1.0 mg/cc (agreement range - 9.4 to 11.4; P > 0.05, no significant difference). Regression analysis between PB-QCT and PL-QCT indicated a good correlation (R-square is 0.9723). Short-term repeatability and reproducibility of proximal humerus BMDs measured by PB-QCT (CV: 5.10% and 3.41%) were slightly better than those of PL-QCT (CV: 6.17% and 5.64%). CONCLUSIONS: We evaluated the bone quality of the proximal humeral using chest CT through the semi-automatic PL-QCT system for the first time. Comparison between it and PB-QCT indicated that it could be a reliable shoulder BMD assessment tool with acceptable accuracy and precision. This study developed and verify a semi-automatic PL-QCT for assessment of proximal humeral bone density based on CT to assist in the assessment of proximal humeral osteoporosis and development of individualized treatment plans for shoulders.

Opportunistic use of lumbar computed tomography and magnetic resonance imaging for osteoporosis screening.

Compared with the healthy patients, patients with osteoporosis had a lower Hounsfield unit (HU) value and a higher vertebral bone quality (VBQ) score. Both the HU value and VBQ score can simply distinguish patients with osteoporosis (OP), with a cutoff value of HU value < 97.06 and VBQ score > 3.08. INTRODUCTION: The purpose of this study is to determine whether the opportunistic use of computed tomography (CT) or magnetic resonance imaging (MRI) is effective for identifying spine surgical patients with OP. METHODS: We retrospectively evaluated 109 lumbar spine surgery patients who received lumbar quantitative CT (QCT) and MRI. Using the area under the curve, the CT-based HU value and MRI-based VBQ score were calculated. Then, based on the QCT results, receiver operating characteristic (ROC) curves were constructed to determine the diagnostic performance of the HU value and VBQ score. RESULTS: The HU value was significantly lower in the OP group, and the VBQ score was significantly higher in the OP group. Using the area under the curve, the diagnostic performance of the HU value and VBQ score for OP were 0.959 and 0.880, respectively. The diagnostic threshold values determined with optimal sensitivity and specificity were an HU value of 97.06 and a VBQ score of 3.08. CONCLUSION: Opportunistic use of CT and MRI can simply distinguish patients with OP, which are expected to be potential alternatives to T-score for the osteoporosis screening.

Association between socioeconomic deprivation and bone health status in the UK biobank cohort participants.

The effect of deprivation on total bone health status has not been well defined. We examined the relationship between socioeconomic deprivation and poor bone health and falls and we found a significant association. The finding could be beneficial for current public health strategies to minimise disparities in bone health. PURPOSE: Socioeconomic deprivation is associated with many illnesses including increased fracture incidence in older people. However, the effect of deprivation on total bone health status has not been well defined. To examine the relationship between socioeconomic deprivation and poor bone health and falls, we conducted a cross-sectional study using baseline measures from the United Kingdom (UK) Biobank cohort comprising 502,682 participants aged 40-69 years at recruitment during 2006-2010. METHOD: We examined four outcomes: 1) low bone mineral density/osteopenia, 2) fall in last year, 3) fracture in the last five years, and 4) fracture from a simple fall in the last five years. To measure socioeconomic deprivation, we used the Townsend index of the participant's residential postcode. RESULTS: At baseline, 29% of participants had low bone density (T-score of heel < -1 standard deviation), 20% reported a fall in the previous year, and 10% reported a fracture in the previous five years. Among participants experiencing a fracture, 60% reported the cause as a simple fall. In the multivariable logistic regression model after controlling for other covariates, the odds of a fall, fracture in the last five years, fractures from simple fall, and osteopenia were respectively 1.46 times (95% confidence interval [CI] 1.42-1.49), 1.26 times (95% CI 1.22-1.30), 1.31 times (95% CI 1.26-1.36) and 1.16 times (95% CI 1.13-1.19) higher for the most deprived compared with the least deprived quantile. CONCLUSION: Socioeconomic deprivation was significantly associated with poor bone health and falls. This research could be beneficial to minimise social disparities in bone health.