Obesity and bone

Effects of a high-fat diet on gut microbiota and possible implications for bone health in male Wistar rats

Diet plays an important role in the composition of gut microbiota. Emerging research suggests that bone homeostasis can also be influenced by the gut microbiota. The aim of this study was to assess possible alterations in gut microbiota in an experimental obesity model induced by a high-fat diet (HFD) and the possible effects on parameters of bone metabolism and remodeling. Male Wistar rats were fed a HFD (60% lipids) or standard (control) diet for 14 weeks. Biochemical and hormonal parameters, bone histomorphometry, bone protein levels, and gut microbiota composition were analyzed. HFD animals exhibited a greater gut microbiota α-diversity represented by the Shannon Index and an increased relative abundance of the Proteobacteria phylum. Histomorphometry detected lower bone formation in the HFD group, accompanied by increased levels of serum and bone leptin and FGF-23 (fibroblast growth factor-23). The Shannon Index was correlated directly with bone FGF-23 (R 0.96, p = 0.04) and inversely with the osteoblastic surface (R -0.95, p = 0.04). The present study disclosed a significant increase in gut microbiota α-diversity and relative abundance of Proteobacteria phylum in obese animals fed a high-fat diet in parallel with increased levels of bone and serum leptin and FGF-23 and lower bone formation. The associations of Shannon Index with bone levels of FGF-23 and reduced osteoblastic surface suggest a link between HFD-induced higher gut microbiota diversity and low bone formation.

The Bone, Exercise, Alendronate, and Caloric Restriction (BEACON) trial design and methods

BACKGROUND

Among older adults living with obesity, intentional weight loss (WL) improves prognosis of many comorbidities. However, concomitant decline in bone mineral density (BMD) limits overall benefit of WL by increasing osteoporotic fracture risk. Identification of intervention strategies to maximize body fat loss, while minimizing harm to the musculoskeletal system, is an important area of clinical research. The main objective of the Bone, Exercise, Alendronate, and Caloric Restriction (BEACON) trial (NCT05764733) is to compare the independent and combined effects of a 12-month intervention of resistance training (RT) plus bone-loading exercises and bisphosphonate use on dietary WL-associated bone loss among 308 older (≥60 years) adults living with an indication for WL and bisphosphonate use.

METHODS

All participants will receive the same group-mediated dietary intervention targeting 8-10 % WL and be randomized to one of four groups: no RT and placebo capsules (NoRT+PL); progressive RT plus bone-loading exercises and placebo capsules (RT++PL); no RT and oral bisphosphonate (70 mg weekly oral alendronate; NoRT+BIS); or progressive RT plus bone-loading exercises and oral bisphosphonate (RT++BIS). Total hip areal (a)BMD measured via dual-energy x-ray absorptiometry (DXA) is the primary, powered study outcome. Secondary skeletal outcome measures include femoral neck and lumbar spine aBMD, high resolution peripheral quantitative computed tomography (HRpQCT) bone assessments of the radius and tibia, and biomarkers of bone turnover.

DISCUSSION

BEACON will address an understudied, yet important, clinical research question by studying the independent and combined effects of two scalable intervention strategies aimed at optimizing skeletal integrity in older adults undergoing WL.

CLINICAL TRIALS REGISTRATION

NCT05764733.

Association between Mild Overweight and Survival: A Study of an Exceptionally Long-Lived Population in the Sardinian Blue Zone

Background/Objectives: Overweight and obesity are generally considered risk factors for premature mortality. However, scientific evidence suggests that among older populations, mild conditions of overweight might be associated with reduced comorbidity and longer survival. This study investigates the potential association between anthropometric parameters and survival among a cohort of nonagenarians in Sardinia, Italy. Methods: This study included 200 subjects (50% females) aged 89 and older, enrolled in 2018 in the Sardinian Blue Zone-a population known for longevity-and followed for up to six years. Anthropometric variables such as body height, weight, age, sex, comorbidity, disability, and food group intake were collected using validated questionnaires and analyzed through multivariable analysis. Results: Out of 200 participants at baseline, 28 (14%) were still alive after six years of follow-up (females 10%, males 18%). Mean survival was 3.36 years (range 0.1-6.9 years) for males and 3.03 years (range 0.2-6.6 years) for females. Participants with a Body Mass Index (BMI) in the range of 25.0-27.0 kg/m2 among males and 25.0-27.2 kg/m2 among females had longer survival compared to those who were underweight (p = 0.002) or obese (p < 0.0001). The Cox proportional hazards regression model, adjusted for age, sex, and comorbidity, revealed a statistically significant association between the BMI and survival, demonstrating an inverted-U relationship. This indicates that mild overweight was associated with a survival advantage compared to both normal weight and obesity. Conclusions: Our study indicates that mild, but not severe, overweight in nonagenarians is associated with extended lifespan. Therefore, primary care physicians and geriatricians should exercise caution before recommending calorie-restricted diets for mildly overweight elderly patients.

Associations between body composition and the risk of fracture according to bone mineral density in postmenopausal women: a population-based database cohort study

OBJECTIVE

We aimed to investigate the associations of body composition and the risk of fracture in postmenopausal women, stratified based on bone mineral density.

METHODS

A population-based cohort study using the database of the National Screening Program for Transitional Ages with women aged 66 years was performed. Bone mineral density was categorized as normal, osteopenia, and osteoporosis. The following body mass index (BMI) categories for general obesity were used: underweight (<18.5), normal (18.5-22.9), overweight (23-24.9), obese (25-29.9), and severely obese (≥30 kg/m2). Waist circumference (WC) used for central obesity assessment was categorized into 5 groups. Newly diagnosed fracture during the follow-up period defined based on ICD-10 codes was the primary outcome.

RESULTS

During 7.7 ± 1.4 years of follow-up, 41 672 (17.9%) participants experienced any fracture, 20 326 (8.7%) experienced vertebral fractures (VFs), and 2883 (1.2%) experienced hip fractures (HFs). The adjusted hazard ratios (aHRs) for any fracture showed a progressive increase with higher BMI and WC categories in individual with osteopenia and osteoporosis. Regarding VF, aHR was highest in severely obese individuals with osteoporosis (aHR [95% CI], 3.45 [2.99-3.97]) and in individuals with WC ≥ 95 cm with osteoporosis (4.79 [4.09-5.60]). The aHR [95% CI] for HF was highest in the underweight group with osteopenia (1.94 [1.16-3.27]) and osteoporosis (2.96 [2.15-4.10]). In central obesity individuals with WC ≥ 95 cm, aHR [95% CI] for HF was 2.80 [1.91-4.91].

CONCLUSIONS

General obesity and central obesity are not protective against any fracture, VF and HF in postmenopausal women with osteopenia or osteoporosis.

Muscle-to-Bone and Soft Tissue-to-Bone Ratio in Children and Adolescents with Obesity

OBJECTIVES

To explore the total and regional muscle-to-bone ratio in children and adolescents with obesity and compare the muscle-to-bone ratio (MBR) and soft tissue-to-bone ratio (SBR) to their peers with normal weight or overweight.

STUDY DESIGN

A total of 219 male and female pediatrics (mean age=12.3±2.5 years) participated in this study. Body composition was assessed with a total body dual X-ray absorptiometry. The MBR was calculated by dividing lean mass by bone mineral content. The SBR was determined by dividing the soft tissue mass (i.e., lean mass+fat mass) by bone mineral content. Differences in total and regional body composition measures between body mass index (BMI) percentile groups was assessed by ANOVA.

RESULTS

The obesity group had significantly higher MBR compared to the normal weight group for total (19.24±1.56 vs. 18.26±1.64), arm (17.11±1.67 vs. 15.88±1.81), and leg (18.41±1.68 vs. 16.62±1.55). Similarly, the obesity group had significantly higher MBR in the leg (18.41±1.68) compared to the overweight group (17.24±1.45). However, the overweight group was not significantly different from the normal weight or the obesity group for total and arm MBR. The total, arm, and leg SBR was significantly different between all BMI groups. Across the entire sample, MBR and SBR were negatively associated with high-density lipoprotein. SBR was positively associated with insulin, HOMA-IR, low-density lipoprotein, very low-density lipoprotein, triglycerides, and systolic blood pressure.

CONCLUSIONS

Children with obesity had a higher MBR and SBR compared to their normal weight peers. In addition, there were significant associations between SBR, higher levels of insulin, atherogenic lipoproteins, and increased systolic blood pressure. Thus, SBR may be useful as a marker for increased cardiometabolic disease risk, though more research in this area is warranted.

Menopause-Related Changes in Body Composition Are Associated With Subsequent Bone Mineral Density and Fractures: Study of Women's Health Across the Nation

During the menopause transition (MT), lean mass decreases and fat mass increases. We examined the associations of these body composition changes during the MT (2 years before to 2 years after the final menstrual period) with bone mineral density (BMD) at the end of the MT and fracture after the MT. We included 539 participants from the Study of Women's Health Across the Nation who were not taking bone-beneficial or bone-detrimental medications before or during the MT. Using multivariable linear regression, we assessed the independent associations of % lean mass loss and % fat mass gain during the MT (mutually adjusted) with femoral neck (FN) and lumbar spine (LS) BMD at the end of the MT, adjusted for pre-MT BMD, pre-MT lean and fat mass, race/ethnicity, Study of Women's Health Across the Nation (SWAN) study site, age, and cigarette use. We used Cox proportional hazards regression to quantify the relations of % lean loss and % fat gain during the MT with fracture after the MT. The Cox model was adjusted for the covariates above plus post-MT use of bone-detrimental medications, and censored at the first use of bone-beneficial medications; we further controlled for FN or LS BMD at the end of the MT. Adjusted for covariates, each standard deviation (SD) (6.9%) increment in lean mass loss was associated with 0.010 g/cm2 lower FN BMD (p < 0.0001); each SD (19.9%) increment in fat mass gain was related to 0.026 g/cm2 greater FN (p = 0.009) and LS (p = 0.03) BMD. Each SD increment in lean mass loss and fat mass gain was associated with 63% (p = 0.001) and 28% (p = 0.05) greater fracture hazard after the MT; associations were essentially unchanged by BMD adjustment. MT-related lean mass loss and fat mass gain were associated differentially with BMD; both were independently related to more fractures. Mitigating MT-related body composition changes may reduce fracture risk. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Low Obesity-Related Indices Are Associated with a Low Baseline Calcaneus Ultrasound T-Score, and a Rapid Decline in T-Score in a Large Taiwanese Population Follow-Up Study

Osteoporosis results in reduced bone strength and an elevated risk of fractures. Both overweight and underweight have been associated with osteoporosis; however, few studies have examined associations between osteoporosis and indices related to obesity. Therefore, the aim of this study was to investigate the associations of obesity-related indices, including body mass index (BMI), waist-hip ratio (WHR), waist-to-height ratio (WHtR), body roundness index (BRI), body adiposity index (BAI), abdominal volume index (AVI), lipid accumulation product (LAP), and visceral adiposity index (VAI), with baseline and change in calcaneus ultrasound T-score between baseline and follow-up (ΔT-score). T-score was measured using ultrasound. A total of 26,983 subjects were enrolled (mean age 51.2 ± 10.4 years). Multivariable analysis showed significant associations between low BMI (per 1 kg/m²; β, 0.065), WHR (per 1%; β, 0.012), WHtR (per 1%; β, 0.024), BRI (per 1; β, 0.079), BAI (per 1; β, 0.032), AVI (per 1; β, 0.049), and LAP (per 1; β, 0.005) with low baseline T-scores (all p < 0.001). Furthermore, there were significant associations between low BMI (per 1 kg/m²; β, 0.005; p = 0.036), BAI (per 1; β, 0.010; p < 0.001), and VAI (per 1; β, 0.017; p = 0.002) with low ΔT-scores. A low baseline T-score was significantly associated with low values of LAP, AVI, BAI, BMI, BRI, WHR, and WHtR but not VAI. In addition, low BMI, BAI, and VAI were significantly associated with low ΔT-scores, representing a rapidly decreasing T-score. Consequently, avoiding being underweight may help prevent osteoporosis in the Taiwanese population.

Effect of Mechanical Stimuli and Zoledronic Acid on the Femoral Bone Morphology in Rats with Obesity and Limited Mobility

Our study aimed to compare the impact of zoledronic acid and whole-body vibration (WBV) as a non-pharmacological method of treatment for early obesity/immobility-related osteoporosis in male rat models. In total, 36 male Wistar rats were assigned to the following groups: obese control with immobility (Control, n = 12) and two experimental groups (n = 12 each), including obese and immobile rats subjected to whole-body vibration with an acceleration level of 3 m/s² g (obesity and immobility + WBV) and obese and immobile rats that received an intramuscular injection of zoledronic acid at a dose of 0.025 mg/kg (obesity and immobility + ZOL). After the 8th and 16th week of treatment, n = 6 rats from each group were euthanized and isolated femora were subjected to a histological examination of bone, and analysis of the expression of osteoprotegerin (OPG) and the receptor activator of nuclear factor kappa-B ligand (RANKL) involved in bone turnover and the amount of thin collagen fibers (PSR stain). The obtained results showed that short-term vibrotherapy (up to 8 weeks) can lead to improvement in bone remodeling in rat models with obesity and limited mobility.

Effect of Body Mass Index on Femur Fracture Location: A Retrospective Database Study

OBJECTIVES

Use a large database design and multivariable analyses to assess the associations between body mass index (BMI) and femur fracture patterns after controlling for other risk factors.

DESIGN

Retrospective cohort study.

SETTING

National insurance claims database of patient records from 2010 to 2018.

PATIENTS/PARTICIPANTS

Patients with femur fracture diagnoses were identified. Patients with multiple fractures within 1 week (polytrauma patients), patients without a BMI diagnosis code within 6 months of fracture, and patients with multiple BMI diagnosis codes (implying a substantial change in weight) were excluded.

INTERVENTION

N/A.

MAIN OUTCOME MEASUREMENTS

Patients were divided into groups based on fracture location: proximal (OTA/AO 31), shaft (OTA/AO 32), or distal (OTA/AO 33). The distribution of femur fractures was compared across BMI categories.

RESULTS

A total of 57,042 patients with femur fracture were identified: 45,586 proximal fractures, 4216 shaft fractures, and 7240 distal fractures. Patients with BMI &lt;29.9 have increased odds ( P &lt; 0.0001) of proximal fracture and decreased odds ( P &lt; 0.0001) of shaft or distal fractures. Patients with BMI &gt;30.0 have decreased odds ( P &lt; 0.0001) of proximal fracture and increased odds ( P &lt; 0.0001) of distal fractures.

CONCLUSIONS

Increasing BMI is associated with a decreased proportion of proximal femur fractures and a corresponding increase in the proportion of shaft and distal fractures. Regression analyses determined that age, sex, osteoporosis, diabetes, and tobacco use are not the cause of this trend.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Obesity and Bone Health: A Complex Relationship

Recent scientific evidence has shown an increased risk of fractures in patients with obesity, especially in those with a higher visceral adipose tissue content. This contradicts the old paradigm that obese patients were more protected than those with normal weight. Specifically, in older subjects in whom there is a redistribution of fat from subcutaneous adipose tissue to visceral adipose tissue and an infiltration of other tissues such as muscle with the consequent sarcopenia, obesity can accentuate the changes characteristic of this age group that predisposes to a greater risk of falls and fractures. Other factors that determine a greater risk in older subjects with obesity are chronic proinflammatory status, altered adipokine secretion, vitamin D deficiency, insulin resistance and reduced mobility. On the other hand, diagnostic tests may be influenced by obesity and its comorbidities as well as by body composition, and risk scales may underestimate the risk of fractures in these patients. Weight loss with physical activity programs and cessation of high-fat diets may reduce the risk. Finally, more research is needed on the efficacy of anti-osteoporotic treatments in obese patients.

Impact of Obesity on Bone Metabolism in Children

Obesity is an epidemic disease that can increase the incidence of type 2 diabetes, cardiovascular disease, malignancy, hypertension, and other health problems that affect the musculoskeletal system. There is a complex interaction between obesity and bone metabolism. In children with obesity, the peroxisome proliferator-activated receptor gamma pathway causes the differentiation of mesenchymal stem cells into adipocytes via osteoblasts, in which results in low bone mass and osteoporosis. Systemic inflammation in obesity has negative effects on bone metabolism. An increase in the number and size of adipose tissue and adipocytokines secreted from adipocytes affect the bone mass of the whole body with hormonal and biochemical effects. The skeletal effects of obesity are mediated by higher oxidative stress and increased production of proinflammatory cytokines. Osteoporosis due to obesity has increased morbidity and mortality in recent years, resulting in important health problems in developed and developing countries.

Mechanoadaptation of the bones of mice with high fat diet induced obesity in response to cyclical loading

An upward trend in childhood obesity implies a great need to determine its effects, both immediate and long-term. Obesity is osteoprotective in adults, but we know very little about the effects of obesity on the growing skeleton, particularly its ability to adapt to load. The objective of this research is to assess bone mechanoadaptation in adolescent obese mice. Ten mice were fed a high-fat diet (HFD) from 4 to 16 weeks of age, while a control group of the same size received a normal diet (ND). At 14 weeks of age, right tibiae were cyclically loaded with a 12 N peak load for HFD mice and a 9 N peak load for ND mice three times a week for two weeks, resulting in equal peak strains of about 2500 microstrain. At 16 weeks of age, mice were sacrificed, and tibiae and gonadal fat pads were dissected. Fat pads were weighed as an obesity indicator, and tibiae were imaged with microCT to measure bone structure. The left tibiae (nonloaded) were subsequently decalcified, stained with osmium, and scanned to quantify marrow fat. Results showed that HFD mice had larger tibial cross-sectional areas compared to ND mice, as well as greater marrow adiposity. However, there was no significant difference in the amount of bone adaptation in the cortical or trabecular bone between the two groups. This indicates that the bones of HFD and ND mice adapt equally well to loading.

Osteogenic and Angiogenic Properties of Heparin as a System for Delivery of Biomolecules for Bone Bioengineering: a Brief Critical Review

The review considers complex, controversial, and individual effects of heparin and its derivatives on the bone and circulatory systems in dependence of the dose, the state of the cells and tissues of the recipient. General data on the anticoagulant activity of heparin and its derivatives are presented; special attention is paid to the effect of heparin on mesenchymal cells and tissues and its role in angiogenesis. We also discuss the ability of heparin to bind osteogenic and angiogenic biomolecules in the context of the development of systems for their delivery and sustained controlled release and propose a schematic representation of the positive and side effects of heparin as a delivery system for biomolecules in tissue engineering.

The Ability of Exercise to Mitigate Caloric Restriction-Induced Bone Loss in Older Adults: A Structured Review of RCTs and Narrative Review of Exercise-Induced Changes in Bone Biomarkers

Despite the adverse metabolic and functional consequences of obesity, caloric restriction- (CR) induced weight loss is often contra-indicated in older adults with obesity due to the accompanying loss of areal bone mineral density (aBMD) and subsequent increased risk of fracture. Several studies show a positive effect of exercise on aBMD among weight-stable older adults; however, data on the ability of exercise to mitigate bone loss secondary to CR are surprisingly equivocal. The purpose of this review is to provide a focused update of the randomized controlled trial literature assessing the efficacy of exercise as a countermeasure to CR-induced bone loss among older adults. Secondarily, we present data demonstrating the occurrence of exercise-induced changes in bone biomarkers, offering insight into why exercise is not more effective than observed in mitigating CR-induced bone loss.

[Osteogenic and angiogenic properties of heparin as a system of biomolecule delivery for bone bioengineering: a brief critical review]

The review discusses the complex, ambiguous and individual effects of heparin and its derivatives on the bone and circulatory systems, in dependence of the dosage, the state of the cells and tissues of recipients. General data on the anticoagulant activity of heparin and its derivatives are presented; aspects of the effect of heparin on mesenchymal cells and tissues and its role in angiogenesis are considered in details. Particular attention is paid to the ability of heparin to bind osteogenic and angiogenic biomolecules: thus us especially important for the development of systems for their delivery and sustained controlled release. A schematic representation of the positive and side effects of heparin as a delivery system for biomolecules in tissue engineering is proposed.

Brachial-ankle pulse wave velocity is associated with the risk of osteoporosis: a cross-sectional evidence from a Chinese community-based cohort

BACKGROUND

Association of arterial stiffness and osteoporosis has been well documented in elderly population. However, it is not clear whether they co-progress from the early stages through common mechanisms. The object of this study was to evaluate possible associations between arterial stiffness and osteoporosis by measuring brachial-ankle pulse wave velocity (baPWV) and the Osteoporosis Self-Assessment Tool for Asia (OSTA) index among a healthy population of Chinese aged 40 years and older. Whether baPWV can be used as a predictor of osteoporosis on OSTA was further assessed.

METHODS

This study was cross-sectional in design. Of 3984 adults aged 40 years and older in the Yunyan district of Guiyang (Guizhou, China) who underwent both OSTA and baPWV measurements within 1 month, 1407 were deemed eligible for inclusion (women, 1088; men, 319).

RESULTS

The mean baPWV was 1475 ± 302 cm/s (range,766-3459 cm/s). baPWV in 110 individuals with high risk of osteoporosis (OSTA index < - 4) was higher than that of individuals with non-high risk (1733 ± 461 cm/s vs. 1447 ± 304 cm/s, P < 0.001). OSTA index was negatively correlated with baPWV(ρ = - 0.296, P < 0.001) after adjusting for age, sex, body mass index, waist circumference, diastolic blood pressure, and creatinine clearance rate. baPWV was an independent predictor for the presence of high risk of osteoporosis (β = - 0.001, P < 0.001) and was consistent across age and sex subgroups, and the optimal baPWV cutoff value for predicting the presence of high risk of osteoporosis and fracture was 1693 cm/s. The AUC was 0.722 (95% confidence interval [CI], 0.667-0.777; P < 0.001, sensitivity of 52.8% and specificity of 83.6%).

CONCLUSIONS

We conclude that arterial stiffness measured by baPWV is well correlated with the severity of osteoporosis evaluated by OSTA. baPWV index may be a valuable tool for identifying individuals with risk of developing osteoporosis.

Comparison of clinical risk factors for incident fracture in obese and non-obese community-dwelling older men

BACKGROUND

Obese older adults have higher bone mineral density (BMD), but other characteristics of obesity may predispose these individuals to fracture. We aimed to compare clinical risk factors for incident fracture in obese and non-obese older men.

METHODS

Body mass index (BMI) and body fat percentage were assessed at baseline by anthropometry and dual-energy X-ray absorptiometry, respectively, in 1625 community-dwelling men aged ≥70 years. Categories for non-obese and obese were <30 kg/m²and ≥30 kg/m² for BMI, and <30% and ≥30% for body fat percentage. Sociodemographic, medical, physical function and blood biochemistry parameters were collected at baseline. Self-reported incident fractures of any type and cause (excluding pathological fractures and fractures of hands, fingers, feet, toes and the skull) were confirmed by radiographic reports and recorded up to 9 years. Hip fractures were followed for 14 years using data linkage.

RESULTS

Prevalence of obesity was 27% according to BMI and 44% according to body fat percentage. There were no differences in incidence of any fracture between non-obese and obese men by BMI (10.7 vs 9.3%, respectively; P > 0.05) or body fat percentage (10.2 vs 10.6%, respectively; P > 0.05). Significant interactions were observed demonstrating that dementia increased hazard for incident any and hip fracture in non-obese men (adjusted hazard ratio 7.08; 95% CI 3.27-15.36 and 8.36; 3.13-22.31, respectively) but not obese men. Past-year falls increased hazard for any fracture in obese men (2.86; 95% CI 1.60-5.10) but not non-obese men while higher luteinizing hormone concentrations reduced hazard for hip fracture in obese men (0.91; 0.85-0.97 per IU/L) but not non-obese men.

CONCLUSIONS

In community-dwelling older men, obesity does not protect against incident fracture. Assessments of falls history and gonadotrophin levels, in addition to established clinical risk factors for fracture, may contribute to improvements in fracture prediction in obese older men.

Two novel pleiotropic loci associated with osteoporosis and abdominal obesity

Aiming to uncover a shared genetic basis of abdominal obesity and osteoporosis, we performed a bivariate GWAS meta-analysis of femoral neck BMD (FNK-BMD) and trunk fat mass adjusted by trunk lean mass (TFMadj) in 11,496 subjects from 6 samples, followed by in silico replication in the large-scale UK Biobank (UKB) cohort. A series of functional investigations were conducted on the identified variants. Bivariate GWAS meta-analysis identified two novel pleiotropic loci 12q15 (lead SNP rs73134637, p = 3.45 × 10-7) and 10p14 (lead SNP rs2892347, p = 2.63 × 10-7) that were suggestively associated and that were replicated in the analyses of related traits in the UKB sample (osteoporosis p = 0.06 and 0.02, BMI p = 0.03 and 4.61 × 10-3, N up to 499,520). Cis-eQTL analysis demonstrated that allele C at rs73134637 was positively associated with IFNG expression in whole blood (N = 369, p = 0.04), and allele A at rs11254759 (10p14, p = 9.49 × 10-7) was negatively associated with PRKCQ expression in visceral adipose tissue (N = 313, p = 0.04) and in lymphocytes (N = 117, p = 0.03). As a proof-of-principle experiment, the function of rs11254759, which is 235 kb 5'-upstream from PRKCQ gene, was investigated by the dual-luciferase reporter assay, which clearly showed that the haplotype carrying rs11254759 regulated PRKCQ expression by upregulating PRKCQ promoter activity (p = 4.60 × 10-7) in an allelic specific manner. Mouse model analysis showed that heterozygous PRKCQ deficient mice presented decreased fat mass compared to wild-type control mice (p = 3.30 × 10-3). Mendelian randomization analysis demonstrated that both FNK-BMD and TFMadj were causally associated with fracture risk (p = 1.26 × 10-23 and 1.18 × 10-11). Our findings may provide useful insights into the genetic association between osteoporosis and abdominal obesity.

Long-Term Effects in Bone Mineral Density after Different Bariatric Procedures in Patients with Type 2 Diabetes: Outcomes of a Randomized Clinical Trial

There is scant evidence of the long-term effects of bariatric surgery on bone mineral density (BMD). We compared BMD changes in patients with severe obesity and type 2 diabetes (T2D) 5 years after randomization to metabolic gastric bypass (mRYGB), sleeve gastrectomy (SG) and greater curvature plication (GCP). We studied the influence of first year gastrointestinal hormone changes on final bone outcomes. Forty-five patients, averaging 49.4 (7.8) years old and body mass index (BMI) 39.4 (1.9) kg/m², were included. BMD at lumbar spine (LS) was lower after mRYGB compared to SG and GCP: 0.89 [0.82;0.94] vs. 1.04 [0.91;1.16] vs. 0.99 [0.89;1.12], p = 0.020. A higher percentage of LS osteopenia was present after mRYGB 78.6% vs. 33.3% vs. 50.0%, respectively. BMD reduction was greater in T2D remitters vs. non-remitters. Weight at fifth year predicted BMD changes at the femoral neck (FN) (adjusted R²: 0.3218; p = 0.002), and type of surgery (mRYGB) and menopause predicted BMD changes at LS (adjusted R²: 0.2507; p < 0.015). In conclusion, mRYGB produces higher deleterious effects on bone at LS compared to SG and GCP in the long-term. Women in menopause undergoing mRYGB are at highest risk of bone deterioration. Gastrointestinal hormone changes after surgery do not play a major role in BMD outcomes.

The Effect of an Abnormal BMI on Orthopaedic Trauma Patients: A Systematic Review and Meta-Analysis

Aims: The aim of this systemic review is to identify the complications that arise in operating on orthopaedic trauma patients with an abnormal body mass index (BMI). Materials and Methods: Systematic literature search using a combination of MESH subject headings and free text searching of Medline, Embase, SCOPUS and Cochrane databases in August 2019. Any orthopaedic injury requiring surgery was included. Papers were reviewed and quality assessed by two independent reviewers to select for inclusion. Where sufficiently homogenous, meta-analysis was performed. Results: A total of 26 articles (379,333 patients) were selected for inclusion. All complications were more common in those with a high BMI (>30). The odds ratio (OR) for high BMI patients sustaining post-operative complication of any type was 2.32 with a 23% overall complication rate in the BMI > 30 group, vs. 14% in the normal BMI group (p < 0.05). The OR for mortality was 3.5. The OR for infection was 2.28. The OR for non-union in tibial fractures was 2.57. Thrombotic events were also more likely in the obese group. Low BMI (<18.5) was associated with a higher risk of cardiac complications than either those with a normal or high BMI (OR 1.56). Conclusion: Almost all complications are more common in trauma patients with a raised BMI. This should be made clear during the consent process, and strategies developed to reduce these risks where possible. Unlike in elective surgery, BMI is a non-modifiable risk factor in the trauma context, but an awareness of the complications should inform clinicians and patients alike. Underweight patients have a higher risk of developing cardiac complications than either high or normal BMI patient groups, but as few studies exist, further research into this group is recommended.

Can body mass index influence the fracture zone in the fifth metatarsal base? A retrospective review

Background

Fifth metatarsal base fracture are a common occurrence in the orthopaedic practice. Literature on the epidemiology of such fractures is scarce. The aim of this analysis was to study the relationship between Body Mass Index (BMI) and the zone of the fifth metatarsal base involved by the fracture.

Methods

Data on adult patients who have been diagnosed with isolated fifth metatarsal base fracture were gathered at our Institution (blinded for review). Age, sex, height, weight and injury mechanism were collected from electronic medical records. Fractures were classified according to the Lawrence and Botte classification (Zone 1, 2 and 3) by three independent reviewers.

Results

From March 2016 to December 2018, 149 patients (109 women and 40 men) have been diagnosed with fifth metatarsal base fracture. Average age and BMI at the time of injury were 51.9 (SD 17.1, range 18–84) and 24.0 (SD 3.8, range 16.4–36.7) respectively. Fracture distribution was 63.8% in zone 1, 23.5% in zone 2, 12.7% in zone 3. 12.1% of patients had a BMI < 20 kg/m2, 57.7% between 20 and 24.9 kg/m2, 22.2% between 25 and 29.9 kg/m2 and 8.0% over 30 kg/m2. No statistically significant differences attributable to sex (p = 0.774) or age (p = 0.379) were found between different zones of fracture. Average BMI was found to be higher in the zone 3 (26.1 ± 4.7 kg/m2) fracture group than in zone 1 (23.7 ± 2.9 kg/m2) (p = 0.031).

Conclusion

The prevalence of proximal diaphysis (zone 3) fractures rises proportionally with BMI in our sample study. BMI appears to have an impact on fifth metatarsal base fractures pattern.

Changes in bone mineral density during 5 years of adjuvant treatment in premenopausal breast cancer patients

PURPOSE

Adjuvant treatment for breast cancer in postmenopausal women is a risk factor for bone loss. However, the association between bone mineral density (BMD) changes in premenopausal breast cancer patients and various adjuvant treatment regimens is not well characterized. In this study, we evaluated the changes in BMD according to adjuvant treatment in premenopausal women with breast cancer.

METHODS

Between 2006 and 2010, BMD data of 910 premenopausal women with breast cancer before operation and 1, 2, 3.5, and 5 years post-operation were retrospectively analyzed. The patients were divided according to the type of treatment: observation (O), tamoxifen (T), chemotherapy (C), C followed by T (C → T), and gonadotropin-releasing hormone (GnRH) agonist with T (G + T).

RESULTS

After 5 years of follow-up, BMD changes were similar between the T and O groups (all p > 0.05). Within 1 year of treatment, the C group showed the most significant BMD loss. The C → T and G + T groups showed more significant BMD loss in the lumbar spine and femur than the O and T groups (both p < 0.001, both). After 1 year of treatment, BMD loss in the lumbar spine was significantly greater in the C → T and G + T groups than in the T group; this tendency was maintained for 5 years of treatment (all p < 0.005).

CONCLUSION

Premenopausal women who received adjuvant treatment which induced menopause showed significant bone loss which lasted for 5 years. Although no significant difference was observed between the O and T groups, tamoxifen treatment during chemotherapy or GnRH agonist treatment might prevent bone loss.

Fat distribution may predict intra- or extra-capsular hip fracture in geriatric patients after falling

INTRODUCTION

Hip fractures can be divided into intra-capsular and extra-capsular fracture based on fracture location; these two types of fracture have different pathogeneses, treatments and prognoses. Many factors influence the patterns of hip fractures, including the injury mechanism, areal bone mineral density and the geometry of the hip. However, the relationship between body composition and hip fracture pattern has not yet been discussed. In this investigation, an analysis of the body compositions of geriatric patients with hip fractures were conducted to identify differences between fat and muscle distributions between patients with intra- and extra-capsular hip fractures.

MATERIAL AND METHODS

From December 2017 to February 2019, 139 patients with a hip fracture were prospectively enrolled in this study. The groups of patients that were diagnosed as having intra- and extra-capsular hip fractures were compared in terms of patient demographics, pre-operative laboratory data, bone mineral density (BMD) and body composition including muscle and fat distributions obtained using dual-energy X-ray absorptiometry (DXA) .

RESULTS

Eighty-six and 53 patients were diagnosed with intra-capsular and extra-capsular hip fractures, respectively. A significantly higher serum glucose level, a lower hemoglobin level, a lower T-score level in the proximal femur region, a lower T-score of all parts of interest, and a lower percentage fat content on the region of bilateral proximal hips (gynoid region) and in the lower limb region, were observed in patients with an extra-capsular hip fracture than in those with an intra-capsular hip fracture. However, with all confounding factors controlled for, only the T-score at the proximal femur, percentage fat content in the region of bilateral proximal hips and the ratio of android fat content to gynoid fat content (A/G ratio) are the most relevant factors in predicting the patterns of hip fracture in geriatric patients after falling.

CONCLUSION

This work demonstrates that lower fat content in the region of bilateral proximal hips and a lower BMD on the proximal femur may predict greater vulnerability of geriatric patients to extra-capsular rather than intra-capsular hip fracture after a falling accident.

Global estrogen receptor-α knockout has differential effects on cortical and cancellous bone in aged male mice

Estrogen receptor-α knockout (ERKO) in female rodents results in bone loss associated with increased osteocyte sclerostin expression; whether this also occurs in males is unknown. Here, we examined the effects of ERKO on femoral cortical geometry, trabecular microarchitecture, and osteocyte sclerostin expression of the femur and lumbar vertebrae. At 14 months of age, male ERKO and wild-type (WT) littermates ( n = 6 per group) were sacrificed, and femora and vertebra were collected. Cortical geometry and trabecular microarchitecture were assessed via micro-computed tomography; osteocyte sclerostin expression was assessed via immunohistochemistry. ANCOVA with body weight was used to compare ERKO and WT for cortical geometry; t-tests were used for all other outcomes. Regardless of skeletal site, ERKO mice had greater trabecular bone volume and trabecular number and decreased trabecular separation compared with WT. In the femoral diaphysis, ERKO had lower total area, cortical area, and cortical thickness compared with WT. The percentage of sclerostin+ osteocytes was increased in ERKO animals in cortical bone but not in cancellous bone of the femur or the lumbar vertebrae. In conclusion, ERKO improved trabecular microarchitecture in aged male mice, but negatively altered femoral cortical geometry associated with a trend towards increased cortical sclerostin expression.

Exercise prevents high fat diet-induced bone loss, marrow adiposity and dysbiosis in male mice

High fat diets can have detrimental effects on the skeleton as well as cause intestinal dysbiosis. Exercise prevents high fat (HF) diet-induced obesity and also improves bone density and prevents the intestinal dysbiosis that promotes energy storage. Previous studies indicate a link between intestinal microbial balance and bone health. Therefore, we examined whether exercise could prevent HF-induced bone pathology in male mice and determined whether benefits correlate to changes in host intestinal microbiota. Male C57Bl/6 mice were fed either a low fat diet (LF; 10 kcal% fat) or a HF diet (60 kcal% fat) and put under sedentary or voluntary exercise conditions for 14 weeks. Our results indicated that HF diet reduced trabecular bone volume, when corrected for differences in body weight, of both the tibia (40% reduction) and vertebrae (25% reduction) as well and increased marrow adiposity (44% increase). More importantly, these effects were prevented by exercise. Exercise also had a significant effect on several cortical bone parameters and enhanced bone mechanical properties in LF but not HF fed mice. Microbiome analyses indicated that exercise altered the HF induced changes in microbial composition by reducing the Firmicutes/Bacteriodetes ratio. This ratio negatively correlated with bone volume as did levels of Clostridia and Lachnospiraceae. In contrast, the abundance of several Actinobacteria phylum members (i.e., Bifidobacteriaceae) were positively correlated with bone volume. Taken together, exercise can prevent many of the negative effects of a high fat diet on male skeletal health. Exercise induced changes in microbiota composition could represent a novel mechanism that contributes to exercise induced benefits to bone health.

Incidence and risk factors for foot fractures in China: A retrospective population-based survey

PURPOSE

The literature lacks population-based epidemiologic studies on the incidence and risk factors for traumatic foot fractures. The purpose of this study was to update information concerning the incidence of foot fractures in China and to identify associated risk factors.

METHODS

All the data on foot fractures were available from the China National Fracture Survey (CNFS), which was conducted between January and May in 2015. A total of 8 provinces, 24 urban cities and 24 rural counties in China were selected, using stratified random sampling and the probability proportional to size method. Individuals who had lived in their current residence for 6 months or longer were personally interviewed about any foot fracture that had occurred in 2014. Questionnaires were completed by every participant for data collection and quality control was accomplished by our research team members. The information included age, gender, height, weight, ethnic group, education, occupation, smoking, alcohol consumption, sleeping time per day, dietary habits and others. Fracture was initially identified by patients' self report and further confirmed by their providing medical records.

RESULTS

A total of 512187 individuals participated in the CNFS. There were 201 patients with foot fractures in 2014. Mean age at the time of fracture was 45.4 years. The incidence rate of foot fractures was 39.2 (95%CI: 33.8-44.7)/100000/year. Fall and traffic accident were the most common causes for foot fractures and over 60% of these occurred at home or on the road. Alcohol consumption, history of previous fracture and average sleep time <7h/d were identified as independent risk factors for foot fractures both in males and females. Cigarette smoking was identified as a significant risk factor for foot fracture in males. For females, BMI >24 kg/m2 was a risk factor whilst living in the west region was associated with a lower incidence rate of foot fracture.

CONCLUSIONS

The present study shows an incidence of 39.2/100000/year of foot fractures in China. Specific public health policies focusing on decreasing alcohol consumption and encouraging individuals to obtain sufficient sleep should be implemented. Females with a higher BMI should focus more on foot health care, especially in those with history of previous fracture.

Could obesity be considered as risk factor for non-vertebral low-impact fractures?

BACKGROUND

It has long been established that obesity plays a positive role against osteoporosis (OP) and low-impact fractures (Fx). However, more recent data has shown higher fracture risk in obese individuals. The aim of this study was to investigate the association between BMI, particularly obesity, OP and low-impact Fx in Brazilian women, as well as to evaluate the SAPORI (Sao Paulo Osteoporosis Risk Index) tool performance to identify low BMD according BMI category.

METHODS

A total of 6182 women aged over 40 years were included in this cross-sectional analysis using data from two large Brazilian studies. All participants performed hip and spine bone mineral density (BMD) measurements and answered a detailed questionnaire about the presence of clinical risk factors (CRFs) related to low BMD and risk fractures. The World Health Organization (WHO) criteria were used to define obesity.

RESULTS

Age-adjusted osteoporosis prevalence was 20.8, 33.6, 47 and 67.1% in obese, overweight, normal and underweight category, respectively. Obesity was present in 29,6% (1.830 women) in the study population and the likelihood of osteoporosis and low-impact Fx compared to a normal BMI in this subgroup was of 0.24 (95% CI 0.20-0.28; p < 0.001) and of 1.68 (95% CI 1.35-2.11; p < 0.001), respectively. However, the hip Fx likelihood was lower in obese compared with non-obese women (OR = 0.44; 95% CI 0.20-0.97). Using an originally validated cut-off, the SAPORI tool sensitivity was significantly hampered in overweight and obese women although the accuracy had remained suitable because of increasing in specificity.

CONCLUSIONS

The osteoporosis prevalence reduced as BMI increased and obesity was associated with low-impact Fx, regardless of the BMD measurements. Moreover, the SAPORI performance was impaired in obese women.

Evaluation of body composition in POF and its association with bone mineral density and sex steroid levels

The study aims to investigate the body composition and bone mineral density (BMD) characteristics and discuss the relationships among body composition, BMD and sex steroid level in POF. A total of 240 POF patients, 240 normal women, and peri/postmenopausal women (Peri-M/Post-M) (260 patients in each group) were included. Compared to the control group, POF patients? strength of left/right lower limb (SLL/SRL), muscle distributing coefficient of lower limbs (MD) decreased however, waist circumference (WC) and hip circumference (HC) increased. The weight, WC, HC, whole body fat percentage (BF%), average fat distribution (FD), MD of POF patients were lower than those among Peri-M and Post-M and BMD were lower than the Peri-M, yet still higher than Post-M. Moreover, BMD were significantly positively correlated with BF%, FD, SLL, MD and estradiol (E2). The factors associated with L2-L4 BMD were E2, SRL, FD and age. For the FN BMD, the factors were FD, E2 and SLL. Therefore, we conclude that maintenance of appropriate weight, physical exercise and hormone replacement treatment (HRT) may have positive effects on increasing BMD, improving muscle mass and muscle strength, preventing osteoporosis.

Bone Health in Women

Bone health is critical to overall health and quality of life. Although genetic factors play a key role in bone formation, there are several external factors that can be modified to preserve bone health. Diet, exercise, menstrual irregularities, medications, disease states, weight, and environmental factors can all affect fracture risk. Osteoporosis is characterized by decrease in bone mass and microarchitectural changes in the bone that increases fracture risk. Screening for osteoporosis may help facilitate treatment before fractures occur. Preventing fractures needs patient and physician understanding of bone health to improve and requires a team effort.

Body Mass Index Trajectories From Birth to Midlife and Vertebral Dimensions in Midlife: the Northern Finland Birth Cohort 1966 Study

Vertebral fracture risk is higher among individuals with small vertebral dimensions. Obesity is a global health problem and may also contribute to bone size and fracture risk. In this work we report the association between life course body mass index (BMI) and vertebral cross-sectional area (CSA) in midlife. The Northern Finland Birth Cohort 1966 study with its 46-year follow-up provided the material for this study. A subsample of 780 individuals had attended lumbar magnetic resonance imaging (MRI) at the age of 46 years, and had records of objectively measured BMI from the ages of 0, 7, 15, 31, and 46 years. Of these, MRI-derived data on vertebral size was available for 682 individuals. We identified latent lifelong BMI trajectories by performing latent class growth modeling (LCGM) on the BMI data, and then used sex-stratified linear regression models to compare the identified trajectory groups in terms of midlife vertebral CSA. Gestational age, education years, adult height, lifelong physical activity, lifelong smoking history, and adulthood diet were assessed as potential confounders. Three distinct trajectory groups ("stable slim," "stable average," and "early onset overweight") were identified among both sexes. Comparisons to the stable slim trajectory revealed that vertebral CSA was significantly (p < 0.001) larger among the stable average and early onset overweight trajectories (69.8 and 118.6 mm² larger among men, 57.7 and 106.1 mm² larger among women, respectively). We conclude that lifelong BMI has a positive association with midlife vertebral size among both sexes. Future studies should characterize the mediating factors of this association.

Is elevated body mass index protective against cervical spine injury in adults?

PURPOSE

Correlate body mass index (BMI) with incidence and type of cervical spine injury seen on CT in adult patients presenting with blunt trauma.

MATERIALS AND METHODS

Retrospective chart review of all adult blunt trauma patients who had a cervical spine CT performed at our level 1 trauma center during an approximately 3-year period.

RESULTS

A statistically significant (p = 0.01) difference in cervical spine injury incidence was present between different BMI groups. Cervical spine injury incidence was 7.7% for underweight (BMI ≤ 18) patients, 7.1% for normal weight (BMI 18-25) patients, 6.2% for overweight/obese (BMI 25-35) patients, and 4.7% for morbidly obese (BMI > 35) patients. Using BMI > 18-25 as a reference group, females with BMI > 25-35 had an adjusted odds ratio (aOR) of 0.56 (CI 0.41-0.75) and females with BMI > 35 had an aOR of 0.42 (CI 0.26-0.70). Males with a BMI ≤ 18 had an aOR of 2.20 (CI 1.12-4.32) and males with BMI > 35 had an aOR of 0.66 (CI 0.46-0.95). A particularly low incidence of cervical spine injury was observed in patients older than 65 in the obese group with a cervical spine injury rate of only 1.4% in this patient population. No statistical significant difference was seen in injury morphology across the BMI groups.

CONCLUSION

An inverse relationship exists between BMI and the overall incidence of cervical spine injury. This protective effect appears to be influenced by gender with elevated BMI having lower relative odds of cervical spine injury in women than in men. A particularly low rate of cervical spine injury was identified in obese patients over the age of 65. Routine imaging of all elderly, obese trauma patients with low energy mechanism of injury may not be warranted.

Diet-induced obesity suppresses cortical bone accrual by a neuropeptide Y-dependent mechanism

OBJECTIVE

To determine whether age and neuropeptide Y (NPY) were involved in the skeletal response to extended periods of diet-induced obesity.

METHODS

Male wild-type (WT) and NPY null (NPYKO) mice were fed a mild (23% fat) high-fat diet for 10 weeks from 6 or 16 weeks of age. Metabolism and bone density were assessed during feeding. Skeletal changes were assessed by microCT and histomorphometry.

RESULTS

High-fat feeding in 6-week-old WT mice led to significantly increased body weight, adiposity and serum leptin levels, accompanied with markedly suppressed cortical bone accrual. NPYKO mice were less susceptible to fat accrual but, importantly, displayed a complete lack of suppression of bone accrual or cortical bone loss. In contrast, when skeletally mature (16 week old) mice underwent 10 weeks of fat feeding, the metabolic response to HFD was similar to younger mice, however bone mass was not affected in either WT or NPYKO. Thus, growing mice are particularly susceptible to the detrimental effects of HFD on bone mass, through suppression of bone accrual involving NPY signalling.

CONCLUSION

This study provides new insights into the relationship between the opposing processes of a positive weight/bone relationship and the negative 'metabolic' effect of obesity on bone mass. This negative effect is particularly active in growing skeletons, which have heightened sensitivity to changes in obesity. In addition, NPY is identified as a fundamental driver of this negative 'metabolic' pathway to bone.

Demographic and socioeconomic factors influencing the incidence of clavicle fractures, a national population-based survey of five hundred and twelve thousand, one hundred and eighty seven individuals

BACKGROUND

This study aims to investigate the population-based incidence of clavicle fracture and the related risk factors in China.

METHODS

All the data on clavicle fractures were available from the China National Fracture Survey (CNFS) database performed in 2015. In the CNFS, all eligible household members were sampled from eight provinces, 24 urban cities, and 24 rural counties in China, using stratified random sampling and the probability proportional to size method. Questionnaires were sent to every participant for data collection. Information on age, gender, height, weight, ethnic group, education, professional, smoking, alcohol consumption, sleeping time per day, dietary habits, and others was collected. Fracture case was identified by patients' self report and further confirmation by medical data.

RESULTS

A total of 512,187 valid questionnaires were collected, and relevant data were extracted and analyzed. There were 89 patients with 89 clavicle fractures in 2014, indicating that the incidence was 17.4 (95%CI, 13.8-21.0) per 100,000 person-years. Traffic accidents and falls were the most predominant cause for clavicle factures, leading to 91.0% of all the injuries. Over 85% of them occurred on the road and at home. Age of 45-64, average sleep time < seven hours/day, smoking, alcohol consumption and history of previous fracture were identified as independent risk factors for clavicle fracture. Overweight (BMI, 24.0-27.9) was a significant protective factor, which was estimated to reduce 72% of the clavicle fractures, compared to normal BMI (18.5-23.9).

CONCLUSIONS

Public health policies focusing on decreasing alcohol consumption, smoking cessation, and encouraging individuals to obtain sufficient sleep should be implemented. Middle-aged individuals with previous history of fracture should strengthen the awareness of prevention and health care and decrease risky activities to reduce the clavicle fractures.

Obesity and type 2 diabetes, not a diet high in fat, sucrose, and cholesterol, negatively impacts bone outcomes in the hyperphagic Otsuka Long Evans Tokushima Fatty rat

BACKGROUND

Obesity and type 2 diabetes (T2D) increase fracture risk; however, the association between obesity/T2D may be confounded by consumption of a diet high in fat, sucrose, and cholesterol (HFSC).

OBJECTIVE

The study objective was to determine the main and interactive effects of obesity/T2D and a HFSC diet on bone outcomes using hyperphagic Otuska Long Evans Tokushima Fatty (OLETF) rats and normophagic Long Evans Tokushima Otsuka (LETO) controls.

METHODS

At 8weeks of age, male OLETF and LETO rats were randomized to either a control (CON, 10 en% from fat as soybean oil) or HFSC (45 en% from fat as soybean oil/lard, 17 en% sucrose, and 1wt%) diet, resulting in four treatment groups. At 32weeks, total body bone mineral content (BMC) and density (BMD) and body composition were measured by dual-energy X-ray absorptiometry, followed by euthanasia and collection of blood and tibiae. Bone turnover markers and sclerostin were measured using ELISA. Trabecular microarchitecture of the proximal tibia and geometry of the tibia mid-diaphysis were measured using microcomputed tomography; whole-bone and tissue-level biomechanical properties were evaluated using torsional loading of the tibia. Two-factor ANOVA was used to determine main and interactive effects of diet (CON vs. HFSC) and obesity/T2D (OLETF vs. LETO) on bone outcomes.

RESULTS

Hyperphagic OLEFT rats had greater final body mass, body fat, and fasting glucose than normophagic LETO, with no effect of diet. Total body BMC and serum markers of bone formation were decreased, and bone resorption and sclerostin were increased in obese/T2D OLETF rats. Trabecular bone volume and microarchitecture were adversely affected by obesity/T2D, but not diet. Whole-bone and tissue-level biomechanical properties of the tibia were not affected by obesity/T2D; the HFSC diet improved biomechanical properties only in LETO rats.

CONCLUSIONS

Obesity/T2D, regardless of diet, negatively impacted the balance between bone formation and resorption and trabecular bone volume and microarchitecture in OLETF rats.

Obesity status influences the relationship among serum osteocalcin, iron stores and insulin sensitivity

BACKGROUND & AIMS

Increased iron stores significantly influence the clinical course of several chronic metabolic diseases. Recent studies have shown that iron overload decreases osteocalcin. We aimed to explore the relationship among osteocalcin, iron stores and insulin sensitivity.

METHODS

Extensive clinical and laboratory measurements, including serum ferritin, cross-linked C-telopeptide of type I collagen (CTX) and osteocalcin (OC) concentrations, were analyzed in 250 adult consecutive Caucasian men. Insulin sensitivity was evaluated through frequently sampled intravenous glucose tolerance tests with minimal model analysis.

RESULTS

Circulating serum ferritin were negatively associated with serum OC and CTX (p = 0.004 and p = 0.045 respectively). In all subjects as a whole, BMI and ferritin contributed to explain 5.2% of OC variance after controlling for age and smoking status. However, the association between OC and insulin sensitivity remained significant only in lean subjects (BMI < 25 kg/m², r = 0.468; p = 0.006) whereas the link between serum ferritin concentration and OC and CTX were significant only in overweight/obese subjects (BMI ≥ 25 kg/m², r = -0.229; p = 0.002 and r = -0.196; p = 0.008, respectively).

CONCLUSIONS

The association of circulating osteocalcin with parameters of insulin sensitivity and iron stores were dependent on obesity status. Increased iron stores could contribute to the detrimental metabolic effects of overweight and obesity on bone.

Meeting report of the 2016 bone marrow adiposity meeting

There is considerable interest in the physiology and pathology, as well as the cellular and molecular biology, of bone marrow adipose tissue (BMAT). Because bone marrow adiposity is linked not only to systemic energy metabolism, but also to both bone marrow and musculoskeletal disorders, this biologic compartment has become of major interest to investigators from diverse disciplines. Bone marrow adiposity represents a virtual multi-tissue endocrine organ, which encompasses cells from multiple developmental lineages (e.g., mesenchymal, myeloid, lymphoid) and occupies all the non-osseous and non-cartilaginous space within long bones. A number of research groups are now focusing on bone marrow adiposity to understand a range of clinical afflictions associated with bone marrow disorders and to consider mechanisms-based strategies for future therapies.

Exercise Decreases Marrow Adipose Tissue Through ß-Oxidation in Obese Running Mice

The relationship between marrow adipose tissue (MAT) and bone health is poorly understood. We used running exercise to ask whether obesity-associated MAT can be attenuated via exercise and whether this correlates with gains in bone quantity and quality. C57BL/6 mice were divided into diet-induced obesity (DIO, n = 14) versus low-fat diet (LFD, n = 14). After 3 months, 16-week-old mice were allocated to an exercise intervention (LFD-E, DIO-E) or a control group (LFD, DIO) for 6 weeks (4 groups, n = 7/group). Marrow adipocyte area was 44% higher with obesity (p < 0.0001) and after exercise 33% lower in LFD (p < 0.0001) and 39% lower in DIO (p < 0.0001). In LFD, exercise did not affect adipocyte number; however, in DIO, the adipocyte number was 56% lower (p < 0.0001). MAT was 44% higher in DIO measured by osmium-μCT, whereas exercise associated with reduced MAT (-23% in LFD, -48% in DIO, p < 0.05). MAT was additionally quantified by 9.4TMRI, and correlated with osmium-µCT (r = 0.645; p < 0.01). Consistent with higher lipid beta oxidation, perilipin 3 (PLIN3) rose with exercise in tibial mRNA (+92% in LFD, +60% in DIO, p < 0.05). Tibial µCT-derived trabecular bone volume (BV/TV) was not influenced by DIO but responded to exercise with an increase of 19% (p < 0.001). DIO was associated with higher cortical periosteal and endosteal volumes of 15% (p = 0.012) and 35% (p < 0.01), respectively, but Ct.Ar/Tt.Ar was lower by 2.4% (p < 0.05). There was a trend for higher stiffness (N/m) in DIO, and exercise augmented this further. In conclusion, obesity associated with increases in marrow lipid-measured by osmium-μCT and MRI-and partially due to an increase in adipocyte size, suggesting increased lipid uptake into preexisting adipocytes. Exercise associated with smaller adipocytes and less bone lipid, likely invoking increased ß-oxidation and basal lipolysis as evidenced by higher levels of PLIN3. © 2017 American Society for Bone and Mineral Research.

National incidence of traumatic fractures in China: a retrospective survey of 512 187 individuals

BACKGROUND

Traumatic fractures place a substantial burden on health-care systems worldwide. Although detailed information about incidence, distribution, and risk factors for traumatic fractures is vital for planning and prevention, in China, national data are unavailable. We aimed to do an up-to-date national survey on the population-weighted incidence of traumatic fractures in China.

METHODS

The China National Fracture Study (CNFS) was a retrospective epidemiological study that recruited a nationally representative sample from eight provinces, 24 urban cities, and 24 rural counties in China using stratified random sampling and the probability proportional to size method. All eligible household members who had lived in their current residence for 6 months or longer were personally interviewed by trained research teams about traumatic fractures of the trunk, arms, or legs (not including the skull, sternum, and ribs) that had occurred in 2014. Telephone surveys were used for participants who were non-contactable after repeated visits. Fracture cases were verified by clinical records, medical history, and radiographs by orthopaedic surgeons and radiologists. We estimated incidence rates for traumatic fractures for the overall population and for subgroups by age and sex, as well as by demographic factors such as ethnic origin, occupation, geographical region, and residency category. We also studied potential associations between fractures and various factors of interest, such as age, ethnic origin, education, smoking, alcohol drinking, sleep time per day, and history of previous fracture. Data were weighted during statistical analysis to ascertain the national incidence rate. This study is registered with the Chinese Clinical Trial Registry, number ChiCTR-EPR-15005878.

FINDINGS

Between Jan 19, 2015, and May 16, 2015, 535 836 individuals were selected and invited to participate in the study. Questionnaires from 23 649 (4%) individuals were excluded due to missing items, insufficient responses, or logical errors. Following exclusions, 512 187 (96%) individuals participated in the CNFS, consisting of 259 649 (51%) boys and men and 252 538 (49%) girls and women. Of these individuals, 1763 individuals had experienced traumatic fractures during 2014 (n=1833). The population-weighted incidence rate of traumatic fractures of the trunk, arms, or legs was 3·21 (95% CI 2·83-3·59) per 1000 population in 2014 (3·65, 3·12-4·18 in men and 2·75, 2·46-3·04 in women). For all ages, sleeping less than 7 h per day was identified as a risk factor for traumatic fractures. We identified previous fracture history as a risk factor for adults aged 15 years and older. Alcohol consumption incurred a risk effect for men aged 15 years and older and women aged 15-64 years.

INTERPRETATION

Our results provide detailed information about fracture incidence, distribution, and risk factors, which can now be used as an up-to-date clinical evidence base for national health-care planning and preventive efforts in China and elsewhere. Specific public health policies that focus on decreasing alcohol consumption, prohibiting drunk driving, promoting smoking cessation, and encouraging individuals to obtain sufficient sleep and maintain a healthy bodyweight should be urgently implemented to help reduce the risk of traumatic fractures.

FUNDING

The Hebei Province Medical Science Special Major Projects Research Fund.

Assessment of Sex Differences in Fracture Risk Among Patients With Anorexia Nervosa: A Population-Based Cohort Study Using The Health Improvement Network

Though previous studies have demonstrated an increased fracture risk in females with anorexia nervosa (AN), fracture risk in males is not well characterized. The objective of this study was to examine sex differences in fracture risk and site-specific fracture incidence in AN. We performed a population-based retrospective cohort study using The Health Improvement Network (THIN; a large database of anonymized electronic medical records collected at primary care clinics throughout the United Kingdom). The median calendar year for the start of the observation period was 2004-2005. We identified 9239 females and 556 males <60 years of age with AN, and 97,889 randomly selected sex-, age-, and practice-matched participants without eating disorders (92,329 females and 5560 males). Multivariable Cox regression was used to estimate the hazard ratio (HR) for incident fracture. Median age at start of observation was 29.8 years in females and 30.2 years in males. The HR for fracture associated with AN differed by sex and age (interaction p = 0.002). Females with AN had an increased fracture risk at all ages (HR, 1.59; 95% confidence interval [CI], 1.45 to 1.75). AN was associated with a higher risk of fracture among males >40 years of age (HR, 2.54; 95% CI, 1.32 to 4.90; p = 0.005) but not among males ≤40 years. Females with AN had a higher risk of fracture at nearly all anatomic sites. The greatest excess fracture risk was noted at the hip/femur (HR, 5.59; 95% CI, 3.44 to 9.09) and pelvis (HR, 4.54; 95% CI, 2.42 to 8.50) in females and at the vertebrae (HR, 7.25; 95% CI, 1.21 to 43.45) for males with AN. AN was associated with higher incident fracture risk in females across all age groups and in males >40 years old. Sites of highest fracture risk include the hip/femur and pelvis in females and vertebrae in males with AN. © 2016 American Society for Bone and Mineral Research.

Body mass index and the risk of low bone mass-related fractures in women compared with men: A PRISMA-compliant meta-analysis of prospective cohort studies

BACKGROUND

Body mass index (BMI) is inconsistently associated with the progression of low bone mass-related fractures. We conducted a systematic review and meta-analysis to summarize the evidence regarding the relationship between BMI and the risk of fracture in men and women separately. Furthermore, we analyzed the association between BMI and fracture risk in women compared with men.

METHODS

PubMed, EmBase, and the Cochrane Library were searched up to November 2015 to identify prospective cohort studies of low bone mass-related fractures. Prospective cohort studies that reported effect estimates of fracture risk for different BMI categories compared to normal weight were included. Relative risk (RR) and the ratio of relative risk (RRR) were calculated using a random-effect model to measure the relationship between BMI and fracture risk.

RESULTS

We analyzed 37 cohorts (32 articles), which included a total of 506,004 women and 118,372 men; overall, 38,200 incident cases were reported. Overall, a lower BMI was not associated with fracture risk in men (RR: 1.50, 95% confidence interval [CI]: 1.00-2.26; P = 0.051) or women (RR: 1.25, 95% CI: 0.97-1.62; P = 0.083). Although a higher BMI might play a beneficial impact in men (RR: 0.80, 95% CI: 0.69-0.93; P = 0.003), it has little effect in women (RR: 0.91, 95% CI: 0.74-1.11; P = 0.343). In addition, an increase in BMI by 5 kg/m decreased the risk of fractures in men (RR: 0.90, 95% CI: 0.83-0.98; P = 0.017) and women (RR: 0.85, 95% CI: 0.81-0.89; P < 0.001). Finally, there was no evidence of a sex difference in the RR for fractures between participants with different BMI categories compared with those with normal BMI. Finally, gender did not affect the risk of fracture for any category of BMI values.

CONCLUSION

Higher BMI may affect the risk of fractures regardless of the sex. This association may be due to the interaction between the participants' BMI and their bone mass density.

Sex-specific association between obesity and self-reported falls and injuries among community-dwelling Canadians aged 65 years and older

This study investigated the relationship between body mass index (BMI) and falls among community-dwelling elderly. Results indicate that obesity is associated with increased falls and there appears to be a sex-specific difference with obese men at higher risk of falling. Obesity is identified as a risk factor for falls in men.

INTRODUCTION

The prevalence of falls, fall-related injuries, and obesity has increased over the last decade. The objectives of this study were to investigate sex-specific association and dose-response relationship between BMI and falls (and related injuries) among community-dwelling elderly.

METHODS

Our study sample consisted of 15,860 adults aged 65 years or older (6399 men and 9461 women) from the 2008-2009 Canadian Community Health Survey-Healthy Aging (CCHS-HA). Falls, fall-related injuries, and BMI measures were self-reported. For both sex, dose-response curves presenting the relationship between BMI, falls, and fall-related injuries were first examined. Thereafter, multivariate logistic regression analyses were also performed to investigate these relationships after adjustment for potentially confounding variables.

RESULTS

Of women, 21.7 % reported a fall and 16.9 % of men. The dose-response relationship between BMI and prevalence of falls showed that underweight and obese individuals reported falling more than normal and overweight individuals; this being more apparent in men than women. Finally, the dose relationship between BMI and prevalence of fall-related injuries showed that only obese men seem more likely to have sustained a fall-related injury. Results from the multivariate analysis showed that obesity in men was significantly associated with higher odds of falling odds ratio (OR) 1.33 (1.04-1.70) and was not significantly associated with higher odds of fall-related injuries OR 1.10 (0.66-1.84) over a 12-month period compared to normal weight men. For women, obesity was not significantly associated with higher fall prevalence OR 0.99 (0.79-1.25) and fall-related injuries OR 0.71 (0.51-1.00).

CONCLUSION

Obesity is associated with self-reported falls, and there appears to be a sex-specific difference in elderly persons.

Age and Sex Differences in Body Mass Index as a Predictor of Hip Fracture: A NOREPOS Study

It is unclear whether very high body mass index (BMI; weight (kg)/height (m)²) lowers risk of hip fracture. Our objectives in this study were 1) to examine the association between BMI and subsequent hip fracture according to sex and age and 2) to explore whether the importance of known risk factors varied across BMI. We followed 61,787 participants (29,511 female and 32,276 male) in the Cohort of Norway (ages 50-79 years at baseline in 1994-2003) with regard to hip fracture. BMI was calculated from measured height and weight. During a median follow-up period of 8.4 years, 1,603 women and 951 men suffered a hip fracture. Hazard ratios for hip fracture and associated 95% confidence intervals were estimated. After adjustment for potential confounders, women with BMI <22 had a hazard ratio of 1.38 (95% confidence interval (CI): 1.18, 1.60) for hip fracture, as compared with women with BMI 22-24.9; and women with BMI ≥30 had a hazard ratio of 0.57 (95% CI: 0.49, 0.66). Corresponding results in men were hazard ratio = 1.66 (95% CI: 1.35, 2.05) and hazard ratio = 0.77 (95% CI: 0.62, 0.96), respectively. Below age 70 years, there was no further decrease in fracture risk at BMIs of 25 or more, while in women aged 70-79 years, the risk continued to decrease with increasing BMI. The associations between risk factors and hip fracture were similar in strength across BMI strata.

Effects of Long-Term Low-Molecular-Weight Heparin on Fractures and Bone Density in Non-Pregnant Adults: A Systematic Review With Meta-Analysis

BACKGROUND

Adults who require long-term anticoagulation with low-molecular-weight heparin (LMWH) such as cancer patients or the elderly may be at increased risk of fractures.

OBJECTIVE

To determine the effects of LMWH therapy of at least 3 months' duration on fractures and bone mineral density (BMD) in non-pregnant adult populations.

METHODS

We systematically reviewed electronic databases (e.g., MEDLINE, EMBASE), conferences and bibliographies until June 2015 and included comparative studies in non-pregnant adult populations that examined the effects of LMWH (≥3 months) on fractures and BMD. We synthesized evidence qualitatively and used random-effects meta-analysis to quantify the effect of LMWH on fractures.

RESULTS

Sixteen articles reporting 14 studies were included: 10 clinical trials (n = 4865 participants) and four observational cohort studies (3 prospective, n = 221; 1 retrospective, n = 30). BMD and fractures were secondary outcomes in the majority of trials, while they were primary outcomes in the majority of observational studies. In participants with venous thromboembolism and underlying cardiovascular disease or cancer (5 RCTs, n = 2280), LMWH for 3-6 months did not increase the relative risk of all fractures at 6-12 months compared to unfractionated heparin, oral vitamin K antagonists or placebo [pooled risk ratio (RR) = 0.58, 95 % CI: 0.23-1.43; I(2) = 12.5 %]. No statistically significant increase in the risk of fractures at 6-12 months was found for cancer patients (RR = 1.08, 95 % CI: 0.31-3.75; I(2) = 4.4 %). Based on the data from two prospective cohort studies (n = 166), LMWH for 3-24 months decreased mean BMD by 2.8-4.8 % (depending on the BMD site) compared to mean BMD decreases of 1.2-2.5 % with oral vitamin K antagonists.

CONCLUSIONS

LMWH for 3-6 months may not increase the risk of fractures, but longer exposure for up to 24 months may adversely affect BMD. Clinicians should consider monitoring BMD in adults on long-term LMWH who are at increased risk of bone loss or fracture.

Change in fracture risk and fracture pattern after bariatric surgery: nested case-control study

OBJECTIVE

 To investigate whether bariatric surgery increases the risk of fracture.

DESIGN

 Retrospective nested case-control study.

SETTING

 Patients who underwent bariatric surgery in the province of Quebec, Canada, between 2001 and 2014, selected using healthcare administrative databases.

PARTICIPANTS

 12 676 patients who underwent bariatric surgery, age and sex matched with 38 028 obese and 126 760 non-obese controls.

MAIN OUTCOME MEASURES

 Incidence and sites of fracture in patients who had undergone bariatric surgery compared with obese and non-obese controls. Fracture risk was also compared before and after surgery (index date) within each group and by type of surgery from 2006 to 2014. Multivariate conditional Poisson regression models were adjusted for fracture history, number of comorbidities, sociomaterial deprivation, and area of residence.

RESULTS

 Before surgery, patients undergoing bariatric surgery (9169 (72.3%) women; mean age 42 (SD 11) years) were more likely to fracture (1326; 10.5%) than were obese (3065; 8.1%) or non-obese (8329; 6.6%) controls. A mean of 4.4 years after surgery, bariatric patients were more susceptible to fracture (514; 4.1%) than were obese (1013; 2.7%) and non-obese (3008; 2.4%) controls. Postoperative adjusted fracture risk was higher in the bariatric group than in the obese (relative risk 1.38, 95% confidence interval 1.23 to 1.55) and non-obese (1.44, 1.29 to 1.59) groups. Before surgery, the risk of distal lower limb fracture was higher, upper limb fracture risk was lower, and risk of clinical spine, hip, femur, or pelvic fractures was similar in the bariatric and obese groups compared with the non-obese group. After surgery, risk of distal lower limb fracture decreased (relative risk 0.66, 0.56 to 0.78), whereas risk of upper limb (1.64, 1.40 to 1.93), clinical spine (1.78, 1.08 to 2.93), pelvic, hip, or femur (2.52, 1.78 to 3.59) fractures increased. The increase in risk of fracture reached significance only for biliopancreatic diversion.

CONCLUSIONS

 Patients undergoing bariatric surgery were more likely to have fractures than were obese or non-obese controls, and this risk remained higher after surgery. Fracture risk was site specific, changing from a pattern associated with obesity to a pattern typical of osteoporosis after surgery. Only biliopancreatic diversion was clearly associated with fracture risk; however, results for Roux-en-Y gastric bypass and sleeve gastrectomy remain inconclusive. Fracture risk assessment and management should be part of bariatric care.

Diabetes and disordered bone metabolism (diabetic osteodystrophy): time for recognition

Diabetes and osteoporosis are rapidly growing diseases. The link between the high fracture incidence in diabetes as compared with the non-diabetic state has recently been recognized. While this review cannot cover every aspect of diabetic osteodystrophy, it attempts to incorporate current information from the First International Symposium on Diabetes and Bone presentations in Rome in 2014. Diabetes and osteoporosis are fast-growing diseases in the western world and are becoming a major problem in the emerging economic nations. Aging of populations worldwide will be responsible for an increased risk in the incidence of osteoporosis and diabetes. Furthermore, the economic burden due to complications of these diseases is enormous and will continue to increase unless public awareness of these diseases, the curbing of obesity, and cost-effective measures are instituted. The link between diabetes and fractures being more common in diabetics than non-diabetics has been widely recognized. At the same time, many questions remain regarding the underlying mechanisms for greater bone fragility in diabetic patients and the best approach to risk assessment and treatment to prevent fractures. Although it cannot cover every aspect of diabetic osteodystrophy, this review will attempt to incorporate current information particularly from the First International Symposium on Diabetes and Bone presentations in Rome in November 2014.

BMI and BMD: The Potential Interplay between Obesity and Bone Fragility

Recent evidence demonstrating an increased fracture risk among obese individuals suggests that adipose tissue may negatively impact bone health, challenging the traditional paradigm of fat mass playing a protective role towards bone health. White adipose tissue, far from being a mere energy depot, is a dynamic tissue actively implicated in metabolic reactions, and in fact secretes several hormones called adipokines and inflammatory factors that may in turn promote bone resorption. More specifically, Visceral Adipose Tissue (VAT) may potentially prove detrimental. It is widely acknowledged that obesity is positively associated to many chronic disorders such as metabolic syndrome, dyslipidemia and type 2 diabetes, conditions that could themselves affect bone health. Although aging is largely known to decrease bone strength, little is yet known on the mechanisms via which obesity and its comorbidities may contribute to such damage. Given the exponentially growing obesity rate in recent years and the increased life expectancy of western countries it appears of utmost importance to timely focus on this topic.

Fracture Risk Is Decreased in Women With Polycystic Ovary Syndrome: A Register-Based and Population-Based Cohort Study

Hyperandrogenism, obesity, and hyperinsulinemia may protect against osteoporosis, whereas amenorrhea, increased cortisol, and low growth hormone may be associated with higher fracture risk in polycystic ovary syndrome (PCOS). The objective of this study was to investigate fracture risk in PCOS. In the PCOS Denmark study, women with PCOS and/or hirsutism were identified in the Danish National Patient Register (1995-2012). Each patient was assigned three age-matched controls on the index date of PCOS diagnosis. Individuals with a previous endocrine diagnosis were excluded. Within PCOS Denmark, we embedded a well-characterized subcohort of patients, PCOS OUH, diagnosed with PCOS at Odense University Hospital (n = 1217). We identified incident fractures by International Classification of Diseases, 10th Revision (ICD-10) codes and used conditional Cox regression analyses to compare fracture risk. In the PCOS Denmark study, there were 19,199 women with PCOS and 57,483 controls were included, mean age 30.6 years (range, 12-60 years). Fracture rates were decreased in PCOS Denmark (10.3/1000 patient years) versus controls (13.6/1000 patient years). The adjusted ORs were 0.76 (95% CI, 0.71 to 0.80) for all fractures, 0.82 (95% CI, 0.74 to 0.92) for major osteoporotic fractures, and 0.57 (95% CI, 0.47 to 0.70) for fractures of head and face. The risk reduction was more pronounced below the age of 30 years at diagnosis. Women with PCOS had significant more hospital contacts due to strains and sprains. In the PCOS OUH subcohort, the risk reduction of fractures did not differ between PCOS women with elevated versus normal testosterone levels and the risk reduction was nominally smaller in overweight versus normal weight PCOS women. Women with PCOS had reduced risk of fractures, in particular of the appendicular skeleton. The risk reduction was greater in women with younger age at diagnosis suggesting that the skeletal effects of PCOS may be greater in women who have not yet reached peak bone mass. Reduced participation in sports activities was probably not the reason for the reduced risk of fractures.