Hip fracture is associated with a reduced risk of type 2 diabetes: A retrospective cohort study.

Objectives: Type 2 diabetes mellitus (T2DM) shares a complex relationship with bone metabolism and few studies investigated the effect of impaired bone health on the risk of T2DM. This study was conducted to investigate the association between hip fractures and the risk of incident T2DM. Methods: This is a retrospective cohort study using data from the real-world hip fracture cohort. Hong Kong Chinese patients aged ≥ 65 years without T2DM who were admitted to public hospitals due to a fall between 2008 and 2015 were included in the study. Patients who sustained falls with and without hip fractures were matched by propensity score (PS) at a 1:1 ratio. Competing risk regression was used to evaluate the association between hip fracture and incident T2DM, with death being the competing event. Results: A total of 23,314 hip fracture cases were matched to 23,314 controls. The median follow-up time was 5.09 years. The incidence rate of T2DM was 11.947 and 14.505 per 1000 person-years for the hip fracture and control group respectively. After accounting for the competing risk of death, the hip fracture group had a significantly lower risk of developing T2DM (HR: 0.771, 95% CI: 0.719-0.827). Similar results were observed in all subgroups after stratification by age and sex. Conclusions: Hip fracture was found to be associated with a reduced risk of T2DM. These findings provide insight into the topic of bone and glucose metabolism and prompt further research in evaluating the role of bone health in the management of T2DM.

Development and validation of sex-specific hip fracture prediction models using electronic health records: a retrospective, population-based cohort study.

Background: Hip fracture is associated with immobility, morbidity, mortality, and high medical cost. Due to limited availability of dual-energy X-ray absorptiometry (DXA), hip fracture prediction models without using bone mineral density (BMD) data are essential. We aimed to develop and validate 10-year sex-specific hip fracture prediction models using electronic health records (EHR) without BMD. Methods: In this retrospective, population-based cohort study, anonymized medical records were retrieved from the Clinical Data Analysis and Reporting System for public healthcare service users in Hong Kong aged ≥60 years as of 31 December 2005. A total of 161,051 individuals (91,926 female; 69,125 male) with complete follow-up from 1 January 2006 till the study end date on 31 December 2015 were included in the derivation cohort. The sex-stratified derivation cohort was randomly divided into 80% training and 20% internal testing datasets. An independent validation cohort comprised 3046 community-dwelling participants aged ≥60 years as of 31 December 2005 from the Hong Kong Osteoporosis Study, a prospective cohort which recruited participants between 1995 and 2010. With 395 potential predictors (age, diagnosis, and drug prescription records from EHR), 10-year sex-specific hip fracture prediction models were developed using stepwise selection by logistic regression (LR) and four machine learning (ML) algorithms (gradient boosting machine, random forest, eXtreme gradient boosting, and single-layer neural networks) in the training cohort. Model performance was evaluated in both internal and independent validation cohorts. Findings: In female, the LR model had the highest AUC (0.815; 95% Confidence Interval [CI]: 0.805-0.825) and adequate calibration in internal validation. Reclassification metrics showed the LR model had better discrimination and classification performance than the ML algorithms. Similar performance was attained by the LR model in independent validation, with high AUC (0.841; 95% CI: 0.807-0.87) comparable to other ML algorithms. In internal validation for male, LR model had high AUC (0.818; 95% CI: 0.801-0.834) and it outperformed all ML models as indicated by reclassification metrics, with adequate calibration. In independent validation, the LR model had high AUC (0.898; 95% CI: 0.857-0.939) comparable to ML algorithms. Reclassification metrics demonstrated that LR model had the best discrimination performance. Interpretation: Even without using BMD data, the 10-year hip fracture prediction models developed by conventional LR had better discrimination performance than the models developed by ML algorithms. Upon further validation in independent cohorts, the LR models could be integrated into the routine clinical workflow, aiding the identification of people at high risk for DXA scan. Funding: Health and Medical Research Fund, Health Bureau, Hong Kong SAR Government (reference: 17181381).

Association of Bone Mineral Density and Bone Turnover Markers with the Risk of Diabetes: Hong Kong Osteoporosis Study and Mendelian Randomization.

Preclinical studies demonstrated that bone plays a central role in energy metabolism. However, how bone metabolism is related to the risk of diabetes in humans is unknown. We investigated the association of bone health (bone mineral density [BMD] and bone turnover markers) with incident type-2 diabetes mellitus (T2DM) based on the Hong Kong Osteoporosis Study (HKOS). A total of 993 and 7160 participants from the HKOS were studied for the cross-sectional and prospective analyses, respectively. The cross-sectional study evaluated the association of BMD and bone biomarkers with fasting glucose and glycated hemoglobin (HbA1c ) levels, whereas the prospective study examined the associations between BMD at study sites and the risk of T2DM by following subjects a median of 16.8 years. Body mass index (BMI) was adjusted in all full models. Mendelian randomization (MR) was conducted for causal inference. In the cross-sectional analysis, lower levels of circulating bone turnover markers and higher BMD were significantly associated with increased fasting glucose and HbA1c levels. In the prospective analysis, higher BMD (0.1 g/cm2 ) at the femoral neck and total hip was associated with increased risk of T2DM with hazard ratios (HRs) of 1.10 (95% confidence interval [CI], 1.03 to 1.18) and 1.14 (95% CI, 1.08 to 1.21), respectively. The presence of osteoporosis was associated with a 30% reduction in risk of T2DM compared to those with normal BMD (HR = 0.70; 95% CI, 0.55 to 0.90). The MR results indicate a robust genetic causal association of estimated BMD (eBMD) with 2-h glucose level after an oral glucose challenge test (estimate = 0.043; 95% CI, 0.007 to 0.079) and T2DM (odds ratio = 1.064; 95% CI, 1.036 to 1.093). Higher BMD and lower levels of circulating bone biomarkers were cross-sectionally associated with poor glycemic control. Moreover, higher BMD was associated with a higher risk of incident T2DM and the association is probably causal. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Osteoporosis is a novel risk factor of infections and sepsis: A cohort study.

Background: Accumulating evidence suggests the interaction of bone metabolism and the immune system, but how bone health is associated with the risk of infections remains unknown. Methods: This study aimed to investigate the relationship of bone mineral density (BMD) with the risk of common infections and sepsis in Hong Kong Osteoporosis Study (HKOS). A prospective cohort study, initiated in 1995 and followed until 31 December 2020, of 5,717 participants examined the association of BMD at three skeletal sites (lumbar spine, femoral neck, and total hip) with common infections - pneumonia, urinary tract infection (UTI), skin infection, and sepsis. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI). Findings: During the median follow-up of 17 years, higher BMD T-scores at the femoral neck and total hip were significantly associated with the reduced risk of pneumonia (HRs 0.89 and 0.87; 95% CIs 0.82 to 0.98 and 0.81 to 0.95), UTI (HRs 0.85 and 0.86; 95% CIs 0.76 to 0.94 and 0.78 to 0.95), skin infection (HRs 0.85 and 0.82; 95% CIs 0.74 to 0.97 and 0.73 to 0.93), and sepsis (HRs 0.83 and 0.82; 95% CIs 0.71 to 0.97 and 0.72 to 0.94). A significant association was observed for the lumbar spine BMD T-score with the risk of skin infection (HR 0.86; 95% CI: 0.78 to 0.95) but not with other infections and sepsis. Similarly, participants with osteoporosis, but not osteopenia, were significantly associated with an increased risk of infections and sepsis compared to those with normal BMD. Interpretation: BMD is a novel risk factor of infections and sepsis. People with low BMD, particularly those with osteoporosis, are at higher risk of infections and sepsis than those with normal BMD. Further studies on whether improving bone health can reduce the risk of infections and sepsis are warranted. Funding: None.

Identification of QTL genes for BMD variation using both linkage and gene-based association approaches.

Low bone mineral density (BMD) is a risk factor for osteoporotic fracture with a high heritability. Previous large scale linkage study in Northern Chinese has identified four significant quantitative trait loci (QTL) for BMD variation on chromosome 2q24, 5q21, 7p21 and 13q21. We performed a replication study of these four QTL in 1,459 Southern Chinese from 306 pedigrees. Successful replication was observed on chromosome 5q21 for femoral neck BMD with a LOD score of 1.38 (nominal p value = 0.006). We have previously identified this locus in a genome scan meta-analysis of BMD variation in a white population. Subsequent QTL-wide gene-based association analysis in 800 subjects with extreme BMD identified CAST and ERAP1 as novel BMD candidate genes (empirical p value of 0.032 and 0.014, respectively). The associations were independently replicated in a Northern European population (empirical p value of 0.01 and 0.004 for CAST and ERAP1, respectively). These findings provide further evidence that 5q21 is a BMD QTL, and CAST and ERAP1 may be associated with femoral neck BMD variation.

Association of Genetic Variants Related to Serum Calcium Levels with Reduced Bone Mineral Density.

CONTEXT: The role of serum calcium in bone metabolism is unknown, even though calcium/vitamin D supplementations have been widely used and are expected to improve bone health. We aim to determine the independent role of serum calcium in bone mineral density (BMD). DESIGN AND SETTING: Two epidemiological analyses with 5478 and 5556 participants from the National Health and Nutrition Examination Survey (NHANES) 2003 to 2006 and the Hong Kong Osteoporosis Study (HKOS) to evaluate the cross-sectional association of serum calcium with BMD. Two-sample Mendelian randomization (MR) studies using genetic variations as instrumental variables to infer causality. Summary statistics of genome-wide association study of serum calcium (N = 39 400) and lifelong whole-body BMD (N = 66 628) were used. MAIN OUTCOME MEASURE: BMD measured by dual-energy X-ray absorptiometry. RESULTS: In NHANES 2003-6 and HKOS, each standard deviation (SD) increase in serum calcium was significantly associated with 0.036-0.092 SD decrease in BMD at various sites (all P < .05). In multivariable inverse-variance weighted MR analysis, genetic predisposition to higher serum calcium level was inversely associated with whole-body BMD after adjustment for serum parathyroid hormone, vitamin D, and phosphate (-0.431 SD per SD increase in serum calcium; 95% CI: -0.773 to -0.089, P = .014). Similar estimates were obtained in sensitivity analyses. CONCLUSIONS: Our study reveals that genetic predisposition to higher serum calcium level per se may have a negative impact on bone metabolism. Whether increased serum calcium caused by calcium/vitamin D supplementations would have the same negative effect on bone remains unknown, which warrants further investigation. In addition to other adverse clinical outcomes, careful use of high-dose supplementations is required.

Low handgrip strength is a predictor of osteoporotic fractures: cross-sectional and prospective evidence from the Hong Kong Osteoporosis Study.

Handgrip strength (HGS) is a potentially useful objective parameter to predict fracture since it is an indicator of general muscle strength and is associated with fragility and propensity to fall. Our objective was to examine the association of HGS with fracture, to evaluate the accuracy of HGS in predicting incident fracture, and to identify subjects at risk of fracture. We analyzed a cross-sectional cohort with 2,793 subjects (1,217 men and 1,576 women aged 50-101 years) and a subset of 1,702 subjects which were followed for a total of 4,855 person-years. The primary outcome measures were prevalent fractures and incident major fragility fractures. Each standard deviation (SD) reduction in HGS was associated with a 1.24-fold increased odds for major clinical fractures even after adjustment for other clinical factors. A similar result was obtained in the prospective cohort with each SD reduction in HGS being associated with a 1.57-fold increased hazard ratio of fracture even after adjustment for clinical factors. A combination of HGS and femoral neck bone mineral density (FN BMD) T-score values (combined T-score), together with other clinical factors, had a better predictive power of incident fractures than FN BMD or HGS T-score alone with clinical factors. In addition, combined T-score has better sensitivity and specificity in predicting incidence fractures than FN BMD alone. This study is the first study to compare the predictive ability of HGS and BMD. We showed that HGS is an independent risk factor for major clinical fractures. Compared with using FN BMD T-score of -2.5 alone, HGS alone has a comparable predictive power to BMD, and the combined T-score may be useful to identify extra subjects at risk of clinical fractures with improved specificity.

Estrogenic effects of ginsenoside Rg1 in endometrial cells in vitro were not observed in immature CD-1 mice or ovariectomized mice model.

OBJECTIVE: The present study was designed to determine whether ginsenoside Rg1 could exert selective estrogenic effects by using both cell lines and an animal model. METHODS: The endometrial Ishikawa cells and preosteoblastic MC3T3-E1 cells were treated with a different dose of Rg1. Immature CD-1 mice and ovariectomized (OVX) C57BL/6J mice were used to study the short-term and long-term estrogenic effects of Rg1, respectively. RESULTS: Rg1 significantly increased estrogen receptor-dependent alkaline phosphatase activity, activated estrogen response element-luciferase activity, and induced the phosphorylation of mitogen-activated protein kinase kinase, extracellular-regulated kinase, and estrogen receptor-α in Ishikawa cells. In contrast, Rg1 did not induce any estrogenic responses in MC3T3-E1 cells. Administration of Rg1 to immature CD-1 mice did not alter their uterine weight or the estrogen-regulated gene expressions in the uterus. Treatment of OVX C57BL/6J mice with Rg1 via mini-osmotic pumps for 3 months did not alter the uterine weight or induce any transcriptional activation of estrogen receptor in the uterus. Rg1 induced Bcl-2 messenger RNA expression in the left ventricular tissue and striatum but failed to alter the bone mineral density in the femur and tibia of the OVX mice. CONCLUSIONS: Rg1 exerted potent estrogenic effects in endometrial cells in vitro as well as in heart and brain tissues in vivo. However, it did not exert any estrogenic effects on reproductive tissues in vivo, nor did it stimulate bone tissues in vitro or in vivo. Our results suggest that the estrogenic effects of Rg1 are distinct from those of estradiol and are cell type and tissue selective.

Assessment of gene-by-sex interaction effect on bone mineral density.

Sexual dimorphism in various bone phenotypes, including bone mineral density (BMD), is widely observed; however, the extent to which genes explain these sex differences is unclear. To identify variants with different effects by sex, we examined gene-by-sex autosomal interactions genome-wide, and performed expression quantitative trait loci (eQTL) analysis and bioinformatics network analysis. We conducted an autosomal genome-wide meta-analysis of gene-by-sex interaction on lumbar spine (LS) and femoral neck (FN) BMD in 25,353 individuals from 8 cohorts. In a second stage, we followed up the 12 top single-nucleotide polymorphisms (SNPs; p < 1 × 10(-5) ) in an additional set of 24,763 individuals. Gene-by-sex interaction and sex-specific effects were examined in these 12 SNPs. We detected one novel genome-wide significant interaction associated with LS-BMD at the Chr3p26.1-p25.1 locus, near the GRM7 gene (male effect = 0.02 and p = 3.0 × 10(-5) ; female effect = -0.007 and p = 3.3 × 10(-2) ), and 11 suggestive loci associated with either FN- or LS-BMD in discovery cohorts. However, there was no evidence for genome-wide significant (p < 5 × 10(-8) ) gene-by-sex interaction in the joint analysis of discovery and replication cohorts. Despite the large collaborative effort, no genome-wide significant evidence for gene-by-sex interaction was found to influence BMD variation in this screen of autosomal markers. If they exist, gene-by-sex interactions for BMD probably have weak effects, accounting for less than 0.08% of the variation in these traits per implicated SNP. © 2012 American Society for Bone and Mineral Research.

Impact of bone marker feedback on adherence to once monthly ibandronate for osteoporosis among Asian postmenopausal women.

AIM: This study assesses the impact of serum carboxy-terminal collagen crosslinks (CTX) bone marker feedback (BMF) on adherence to ibandronate treatment in Asian postmenopausal women with osteoporosis. METHODS: This was a 12-month (6-monthly phased), randomized, prospective, open-label, multi-center study conducted in 596 (of 628 enrolled) postmenopausal women with osteoporosis (< or = 85 years old) who were naïve, lapsed, or current bisphosphonate users. Patients were randomized into two arms: serum CTX BMF at 3 months versus no-BMF. Once-monthly 150 mg ibandronate tablet was administered for 12 months and adherence to therapy was assessed at 6 and 12 months. In addition, patient satisfaction and safety of ibandronate treatment were also assessed. RESULTS: Serum CTX BMF at 3 months showed no impact on adherence. The proportions of adherent patients were comparable in the BMF versus no-BMF arms (92.6%vs. 96.0%, P = 0.16); overall, serum CTX levels were similar for adherent and non-adherent patients. However, BMF patients felt more informed about their osteoporosis (P < 0.001) and more satisfied (P < 0.01) than no-BMF patients. CONCLUSIONS: The Asian postmenopausal osteoporosis patients in this study had a high adherence rate to once-monthly ibandronate therapy. Use of serum CTX BMF had no further impact on increasing adherence, but increased treatment satisfaction.

Comparison of raloxifene and bisphosphonates based on adherence and treatment satisfaction in postmenopausal Asian women.

We evaluated adherence with raloxifene therapy compared with daily bisphosphonate in Asian postmenopausal women at increased risk of osteoporotic fractures. In this 12-month observational study conducted in Asia (Hong Kong, Malaysia, Pakistan, Philippines, Singapore, Taiwan), 984 postmenopausal women (aged 55 years or older) were treated with raloxifene 60 mg/day (n = 707; 72%) or daily bisphosphonate (alendronate 10 mg/day; n = 206; 21%, or risedronate 5 mg/day; n = 71; 7%) during their normal course of care. Patients were assessed at baseline, 6, and 12 months. Baseline characteristics (including age, race, education, menopausal status, and baseline fractures) were comparable between the raloxifene and bisphosphonate groups. More women on raloxifene completed the study compared with those on bisphosphonate (50.2% versus 37.5%; P < 0.001). Patients also took raloxifene for a longer period than bisphosphonate (median, 356 versus 348 days; P = 0.011). Compared with those taking bisphosphonate, significantly fewer patients taking raloxifene discontinued the study because of stopping treatment (5.7% versus 10.1%, P = 0.017) or changing treatment (2.8% versus 9.7%, P < 0.001). Inconvenient dosing was reported as a primary reason for discontinuation due to stopping or changing treatment in 19 (6.9%) bisphosphonate patients compared with 0 raloxifene patients. The percentage of patients who had consumed 80% or more of their study medication was similar for raloxifene patients (48-56 weeks; 95.2%) and bisphosphonate patients (48-56 weeks; 93.3%). More raloxifene patients responded that they were satisfied with their medication than bisphosphonate patients at 48-56 weeks (P = 0.002). We concluded that Asian postmenopausal women at increased risk of osteoporotic fractures showed a greater propensity to remain on raloxifene compared with bisphosphonate. The women on raloxifene exhibited lower discontinuation rates and higher treatment satisfaction.