The obesity paradox and osteoporosis

The Relationship Between BMI and Lung Function in Populations with Different Characteristics: A Cross-Sectional Study Based on the Enjoying Breathing Program in China

Purpose

To analyze the relationship between body mass index (BMI) and lung function, which may help optimize the screening and management process for chronic obstructive pulmonary disease (COPD) in the early stages.

Patients and Methods

In this cross-sectional study using data from the Enjoying Breathing Program in China, participants were divided into two groups according to COPD Screening Questionnaire (COPD-SQ) scores (at risk and not at risk of COPD) and three groups based on lung function (normal lung function, preserved ratio impaired spirometry [PRISm], and obstructive lung function).

Results

A total of 32,033 subjects were enrolled in the current analysis. First, in people at risk of COPD, overweight and obese participants had better forced expiratory volume in one second (FEV1; overweight: 0.33 liters (l), 95% confidence interval [CI]: 0.27 to 0.38; obesity: 0.31 L, 95% CI: 0.22 to 0.39) values than the normal BMI group. Second, among people with PRISm, underweight participants had a lower FEV1 (−0.56 L, 95% CI: −0.86 to −0.26) and forced vital capacity (FVC; −0.33 L, 95% CI: −0.55 to −0.11) than participants with a normal weight, and obese participants had a higher FEV1 (0.22 L, 95% CI: 0.02 to 0.42) and FVC (0.16 L, 95% CI: 0.02 to 0.30) than participants with a normal weight. Taking normal BMI as the reference group, lower FEV1 (−0.80 L, 95% CI: −0.97 to −0.63) and FVC (−0.53 L, 95% CI: −0.64 to −0.42) were found in underweight participants with obstructive spirometry, and better FEV1 (obesity: 0.26 L, 95% CI: 0.12 to 0.40) was found in obese participants with obstructive spirometry.

Conclusion

Being underweight and severely obese are associated with reduced lung function. Slight obesity was shown to be a protective factor for lung function in people at risk of COPD and those with PRISm.

Quality of Life in osteoporotic patients

Background

Osteoporosis is responsible for fragility fractures, which are associated with impaired quality of life (QoL) and disability.

Objective

The aim of the study was to evaluate the QoL in patients affected by osteoporosis and possible determinants.

Methods

One-hundred thirty-four subjects followed at the osteoprosis outpatient clinic at our institution completed the QUALEFFO-41 questionnaire for quality of life. All subjects had undergone bone densitometry measurement and the FRAX index, summarizing the risk of fragility fracture, was calculated for each of them. The QoL in these subjects and its possible determinants were investigated with univariate and multiple linear regression analysis.

Results

Subjects with osteoporosis had lower scores in the domains of physical and social function of the QUALEFFO questionnaire in comparison with subjects with normal bome mineral density. Main factors associated with impairment in QoL were high FRAX score and body mass index (BMI).

Conclusion

Physical and social function is reduced in osteoporotic subjects. High BMI and an increased risk of fragility fracture were main determinants of impairment in the QoL in this study.

Inflammation and Bone Turnover Markers in Adult Obesity

Obesity is a condition of abnormally increased body fat resulting from increased energy intake relative to energy expenditure. Excess body weight is a risk factor for many somatic and psychological disorders, including cardiovascular disease, type 2 diabetes mellitus, osteoarthritis, and cancer types. Bone metabolism, bone turnover, and mineral content are altered in severe obesity. This review will focus on the relationship between inflammation and bone biomarkers in adult obesity.

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 <29.9 have increased odds ( P < 0.0001) of proximal fracture and decreased odds ( P < 0.0001) of shaft or distal fractures. Patients with BMI >30.0 have decreased odds ( P < 0.0001) of proximal fracture and increased odds ( P < 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.

Management of eating disorders for people with higher weight: clinical practice guideline

INTRODUCTION

The prevalence of eating disorders is high in people with higher weight. However, despite this, eating disorders experienced by people with higher weight have been consistently under-recognised and under-treated, and there is little to guide clinicians in the management of eating disorders in this population.

AIM

The aim of this guideline is to synthesise the current best practice approaches to the management of eating disorders in people with higher weight and make evidence-based clinical practice recommendations.

METHODS

The National Eating Disorders Collaboration Steering Committee auspiced a Development Group for a Clinical Practice Guideline for the treatment of eating disorders for people with higher weight. The Development Group followed the 'Guidelines for Guidelines' process outlined by the National Health and Medical Research Council and aim to meet their Standards to be: 1. relevant and useful for decision making; 2. transparent; 3. overseen by a guideline development group; 4. identifying and managing conflicts of interest; 5. focused on health and related outcomes; 6. evidence informed; 7. making actionable recommendations; 8. up-to-date; and, 9. accessible. The development group included people with clinical and/or academic expertise and/or lived experience. The guideline has undergone extensive peer review and consultation over an 18-month period involving reviews by key stakeholders, including experts and organisations with clinical academic and/or lived experience.

RECOMMENDATIONS

Twenty-one clinical recommendations are made and graded according to the National Health and Medical Research Council evidence levels. Strong recommendations were supported for psychological treatment as a first-line treatment approach adults (with bulimia nervosa or binge-eating disorder), adolescents and children. Clinical considerations such as weight stigma, interprofessional collaborative practice and cultural considerations are also discussed.

CONCLUSIONS

This guideline will fill an important gap in the need to better understand and care for people experiencing eating disorders who also have higher weight. This guideline acknowledges deficits in knowledge and consequently the reliance on consensus and lower levels of evidence for many recommendations, and the need for research particularly evaluating weight-neutral and other more recent approaches in this field.

Overweight and abdominal fat are associated with normal bone mineral density in patients with ulcerative colitis

BACKGROUND

Low bone mineral density (BMD) is common in patients with inflammatory bowel disease. However, nutritional risk factors for low BMD in the ulcerative colitis (UC) population are still poorly understood.

AIM

To investigate the association of anthropometric indicators and body composition with BMD in patients with UC.

METHODS

This is a cross-sectional study on adult UC patients of both genders who were followed on an outpatient basis. A control group consisting of healthy volunteers, family members, and close people was also included. The nutritional indicators evaluated were body mass index (BMI), total body mass (TBM), waist circumference (WC), body fat in kg (BFkg), body fat in percentage (BF%), trunk BF (TBF), and also lean mass. Body composition and BMD assessments were performed by dual-energy X-ray absorptiometry.

RESULTS

The sociodemographic characteristics of patients with UC (n = 68) were similar to those of healthy volunteers (n = 66) (P > 0.05). Most patients (97.0%) were in remission of the disease, 58.8% were eutrophic, 33.8% were overweight, 39.0% had high WC, and 67.6% had excess BF%. However, mean BMI, WC, BFkg, and TBF of UC patients were lower when compared to those of the control group (P < 0.05). Reduced BMD was present in 41.2% of patients with UC (38.2% with osteopenia and 2.9% with osteoporosis) and 3.0% in the control group (P < 0.001). UC patients with low BMD had lower BMI, TBM, and BFkg values than those with normal BMD (P < 0.05). Male patients were more likely to have low BMD (prevalence ratio [PR] = 1.86; 95% confidence interval [CI]: 1.07-3.26). Those with excess weight (PR = 0.43; 95%CI: 0.19-0.97) and high WC (PR = 0.44; 95%CI: 0.21-0.94) were less likely to have low BMD.

CONCLUSION

Patients with UC in remission have a high prevalence of metabolic bone diseases. Body fat appears to protect against the development of low BMD in these patients.

Distribution of Fracture Sites in Postmenopausal Overweight and Obese Women: The FRISBEE Study

The association between obesity and fracture sites in postmenopausal women has been little studied. We examined the most common types of fractures in obese and overweight postmenopausal women compared to subjects with a normal BMI in the FRISBEE study, a cohort of postmenopausal women followed since 9.1 (7.2-10.6) years. Chi-squared tests and logistic regressions were used to compare the percentages of fracture sites in overweight/obese subjects to subjects with a normal BMI. Their mean (± SD) age was 76.7 ± 6.9 years and their mean BMI was 26.4 ± 4.4. Seven hundred seventy-seven subjects suffered at least one validated fragility fracture with a total of 964 fractures in the whole cohort. Subjects with a BMI higher than 25 had significantly more ankle fractures and less pelvic fractures than subjects with a normal BMI (OR 1.63, 95% CI 1.02-2.56, P = 0.04 and OR 0.55, 95% CI 0.34-0.89, P = 0.01, respectively). There were no significant differences between overweight and obese subjects. Among those older than 75, there were significantly fewer pelvic fractures in overweight/obese subjects (OR 0.49, 95% CI 0.27-0.87, P = 0.01), but before 75, ankle fractures were significantly more frequent in overweight/obese subjects than in subjects with a normal BMI (OR 1.89, 95% CI 1.01-3.57, P = 0.04). In conclusion, the proportion of ankle and pelvic fractures in obese and overweight subjects differs from that in subjects with a normal BMI, but these differences are age dependent. Fracture prevention strategies should take into account the differential effects of excess weight according to age and the site of fracture.

Analysis of the prevalence, risk factors, and clinical characteristics of osteoporosis in patients with essential hypertension

BACKGROUND

The present study investigated the prevalence of osteoporosis (OP) among patients with essential hypertension (EH) in the Changchun community and analysed the correlation between EH and OP.

METHODS

The study included 425 subjects with EH and 425 age- and sex-matched healthy controls. Bone mineral density (BMD) and serum creatinine (CR) levels were measured, and the subjects' current EH and OP statuses were surveyed to analyse the correlation between EH and OP.

RESULTS

The EH group exhibited lower BMD and a higher rate of having OP than the control group, and this difference was statistically significant (p < 0.05). A significant sex difference in the BMD T-score was observed among the subjects (male: - 1.19 ± 1.55, female: - 1.70 ± 1.34). In both the EH group and the control group, the rate of having OP in females was greater than that in males. However, the OP prevalence among subjects with EH varied significantly by age, body weight, fracture history, nocturnal urination frequency, depression and anxiety status, duration of hypertension, and antihypertensive medication use (p < 0.05). Two-way analysis of variance suggested an effect of the interaction between different EH statuses and bone mass conditions on the serum CR values (F = 3.584, p = 0.028, bias η² = 0.008).

CONCLUSIONS

The prevalence of OP and low BMD were significantly higher among subjects with EH than among healthy controls. Additionally, the findings indicate that age, weight, fracture history, nocturnal urination frequency, depression and anxiety, duration of hypertension and antihypertensive drug use may be correlated to having OP in EH subjects, requiring further studies. Moreover, serum CR levels in subjects with different bone mass profiles were strongly influenced by the presence or absence of EH, and the serum CR levels differed significantly with the interaction of these two factors.

The relationship between central obesity and bone mineral density: a Mendelian randomization study

BACKGROUND

The relationship between obesity and osteoporosis is an important public health issue. The goal of this study was to investigate whether and to what extent central obesity traits affect bone mineral density (BMD).

METHODS

We conducted a two-sample Mendelian randomization analysis. Genomewide significant single nucleotide polymorphisms associated with waist circumference, hip circumference, waist-to-hip ratio, waist circumference adjusted by body mass index (WCadjBMI), hip circumference adjusted by BMI (HCadjBMI) and waist-to-hip ratio adjusted by BMI (WHRadjBMI) were obtained from a large-scale database containing 224,459 samples. The BMD summary dataset was obtained from a UK Biobank database including 265,627 participants.

RESULTS

The results provided strong evidence that the HCadjBMI trait was causally and negatively associated with BMD (β: - 0.135, 95% CI - 0.216 to - 0.054; P = 0.001), while the WHR trait was causally and positively associated with BMD (β: 0.194, 95% CI 0.062 to 0.325, P = 0.004). No significant effects were observed for other traits on BMD.

CONCLUSIONS

This study indicates variations in the abilities of different central obesity traits to influence BMD. These results should be considered in further studies and public health measures on obesity and osteoporosis prevention strategies.

Influence of Obesity on Bone Turnover Markers and Fracture Risk in Postmenopausal Women

Background and aims: The relationship between obesity and bone metabolism is controversial. In recent decades, the protective role of obesity in the development of osteoporosis is questioned. The aims of this study are the following: to evaluate the differences in bone turnover markers between postmenopausal women with and without obesity and to compare the risk of fracture at five years between these groups. Methods: An observational longitudinal prospective cohort study of postmenopausal women with obesity (O) (body mass index (BMI) > 30 kg/m2) and non-obesity (NoO) (BMI < 30 kg/m2) is designed. 250 postmenopausal women are included in the study (NoO: 124 (49.6%) and O: 126 (50.4%)). It measures epidemiological variables, dietary variables (calcium intake, vitamin D intake, smoking, alcohol consumption, and physical activity), biochemicals (β-crosslap, type I procollagen amino-terminal peptide (P1NP), 25OH-vitamin D, and parathyroid hormone (PTH)), anthropometric variables, and fracture data five years after the start of the study. The mean age is 56.17 (3.91) years. Women with obesity showed lower levels of vitamin D (O: 17.27 (7.85) ng/mL, NoO: 24.51 (9.60) ng/mL; p < 0.01), and higher levels of PTH (O: 53.24 (38.44−65.96) pg/mL, NoO: 35.24 (25.36−42.40) pg/mL; p < 0.01). Regarding the bone formation marker (P1NP), it was found to be high in women without obesity, O: 45.46 (34.39−55.16) ng/mL, NoO: 56.74 (45.34−70.74) ng/mL; p < 0.01; the bone resorption marker (β-crosslap) was found to be high in women with obesity, being significant in those older than 59 years (O: 0.39 (0.14) ng/mL, NoO 0.24 (0.09) ng/mL; p < 0.05). No differences are observed in the risk of fracture at 5 years based on BMI (OR = 0.90 (95%CI 0.30−2.72); p = 0.85). Conclusions: Postmenopausal women with obesity showed lower levels of bone formation markers; older women with obesity showed higher markers of bone resorption.

Associations of variability in body weight and glucose levels with the risk of hip fracture in people with diabetes

BACKGROUND

Diabetes is associated with a high risk of fragility fracture. However, there are controversies regarding the effect of fluctuations in metabolic parameters on the risk of fracture. We aimed to investigate the associations of body weight or glucose variability or their combination with the risk of hip fracture in people with diabetes.

METHODS

A population-based cohort study with 480,539 subjects over 40 years who had undergone three or more health examinations was performed. The degree of variability was evaluated using variability independent of the mean (VIM, 100 × standard deviation / mean^beta), coefficient of variation (CV), and average real variability (ARV, average of the absolute differences between consecutive values). High variability was defined as having values in the highest quartile. Cox proportional hazards models were used to estimate the risk of hip fracture.

RESULTS

There were 2834 hip fracture events (0.59%) during the mean follow-up of 8.1 years. After multivariable adjustment for age, sex, alcohol consumption, smoking, regular exercise, income, glucose, body mass index, hemoglobin, estimated glomerular filtration rate, diabetes duration, diabetes treatment with multiple agents, and osteoporosis, the HRs (95% CI) of hip fracture were 1.36 (1.24-1.50) and 1.29 (1.16-1.43) for high body weight VIM and high glucose VIM, respectively. The HR (95% CI) of both high VIM group was 1.63 (1.44-1.83), suggesting an additive effect of variabilities in body weight and glucose. The results were consistent when using CV and ARV and in various sensitivity analyses.

CONCLUSIONS

High variability in body weight and glucose levels is associated with an increased incidence rate and risk of hip fracture in people with diabetes.

Elevated body mass index is associated with tibial plateau fracture complexity and post-operative complications

Introduction

As the average body mass index (BMI) is increasing at an alarming rate, dichotomous literature exists regarding whether BMI is protective or disadvantageous for fracture risk. Therefore, the purpose of this study was to evaluate the relationship between BMI, fracture complexity, and post-operative complications for tibial plateau fractures.

Methods

A retrospective analysis of the National Surgical Quality Improvement Program’s database for the years 2005–2018 was completed. Only patients undergoing primary surgical fixation of an isolated tibial plateau fracture were included. Patients were then stratified into unicondylar and bicondylar fracture patterns by CPT code. Multivariate logistic regression analyses were used to assess risk factors for fracture severity, post-operative complications, and staged fixation.

Results

Of the 3454 patients identified for inclusion, we found that patients with higher BMIs were more likely to sustain a bicondylar fracture compared with patients with lower BMIs. For each additional BMI point, the risk of sustaining a bicondylar fracture increased by 1.0%. Additionally, there was a 3.8% increased risk of surgical complications for every increased BMI point. Specifically, the risk of a deep infection increased by 6.1%, wound dehiscence by 8.5%, and venous thromboembolism by 4.2%.

Conclusion

This data demonstrates that an elevated BMI is associated with increased tibial plateau fracture complexity and post-operative complications. These results may be used to help surgeons and hospitals identify at-risk patients to help guide perioperative management in an effort to help mitigate such complications as much as possible.

Association of Polymorphisms in Estrogen Receptor Genes (ESR1 and ESR2) with Osteoporosis and Fracture-Involvement of Comorbidities and Epistasis

Single-nucleotide polymorphisms (SNPs) in the ESR1/ESR2 genes play a role in osteoporosis (OP). Our objective was to determine associations of polymorphisms in ESR genes with OP and fracture, SNP-SNP interactions, and involvement of comorbidities. We analyzed 170 Mexican osteoporotic women (FNOP), 173 with hip fracture (HFx), and 210 controls. The SNPs, ESR1 rs2234693CC, rs851982CC and rs1999805AA, were associated with reduced OP risk (odds ratios [ORs] = 0.35, 0.40 and 0.32, respectively; p < 0.05); rs2234693CC was associated with reduced fracture risk (OR = 0.24; p < 0.05). The obese/overweight carriers of rs9340799GG had a lower OP (OR = 0.15, p = 0.016) and fracture (OR = 0.12, p = 0.0057) risk. The rs9479055AA and rs3020404AA hypertensive carriers had a higher OP risk (OR = 5.96, p = 0.032; and OR = 5.29, p = 0.02, respectively). In addition, rs3020404AA had a higher risk of fracture (OR = 4.90, p = 0.045). The rs2228480GG hypertensive carriers had a higher risk of fracture (OR = 6.22, p = 0.0038). We found a synergic relation between the ESR1 rs3020331 and rs1999805 in femoral neck OP and HFx. The rs2234693 (PvuII) and rs9340799 (XbaI) polymorphisms are associated with a high risk forming a haplotype. The epistasis analysis suggests the contribution of both genes (ESR1/ESR2) to the risk of OP and fracture. Epistasis and involvement of obesity and hypertension lead to a significant modification of the risk.

Circulating SIRT1 and Sclerostin Correlates with Bone Status in Young Women with Different Degrees of Adiposity

Sirtuin1 (SIRT1) and sclerostin play important roles in adipose tissue and bone metabolism. We evaluated the circulating SIRT1 and sclerostin relationship with mass and quality of bone while considering the degree of adiposity. Sixty-six premenopausal women (16 underweight, 25 normal weight and 25 with obesity), aged <50 years, were enrolled. Plasma SIRT1, sclerostin and DXA body composition (total fat mass (FM), abdominal visceral adipose tissue, lean mass, trabecular bone score (TBS) and lumbar spine and femoral neck (FN) bone mineral density (BMD)) were assessed. The patients with obesity showed the lowest SIRT1 and TBS values and the highest sclerostin concentrations; BMD increased with FM and BMI and had an inverse association with SIRT1. Sclerostin was negatively correlated with SIRT1 (ρ = −0.37, p = 0.002). When spine BMD, FN BMD and TBS were standardized for BMI, a positive correlation with SIRT1 and a negative correlation with sclerostin were seen (p < 0.005). In the regression analysis, sclerostin was the best independent, negative predictor for BMD and TBS, while SIRT1 directly predicted TBS (p < 0.05). In conclusion, blood measurement of SIRT1 and sclerostin could represent a snapshot of the bone status that, taking into account the degree of adiposity, may reduce the interference of confounding factors in the interpretation of bone health parameters.

Characteristics of Long-Term Femoral Neck Bone Loss in Postmenopausal Women: A 25-Year Follow-Up

The aim of this study was to monitor long-term changes in bone mineral density (BMD) after menopause and factors affecting BMD. The study population consisted of a random sample of 3222 women from the Kuopio Osteoporosis Risk Factor and Prevention (OSTPRE) study, of which 62.1% were postmenopausal at the beginning of the study. This group of women underwent dual-energy X-ray absorptiometry (DXA) measurements at the femoral neck every 5 years from baseline (in 1989) up to 25-year follow-up. They also responded to risk-factor questionnaires at 5-year intervals. During the 25-year follow-up, the baseline cohort decreased to 686 women. The women were divided into quartiles based on their baseline BMD. Self-reported hormone replacement therapy (HRT) and corticosteroid use were divided into ever users and never users. Morbidity was assessed as the total number of self-reported diseases and BMD-affecting diseases. The mean 25-year BMD change was found to be -10.1%, p < 0.001. Higher baseline BMD was associated with higher bone loss rate; the reduction in the highest quartile BMD was 11.1% and in the lowest quartile 7.4% (p = 0.0031). Lower baseline body mass index (BMI) and a greater increase in BMI were found to protect against postmenopausal bone loss (p < 0.001). The lowest bone loss quartile included 15.2% more HRT users than the highest bone loss quartile (p = 0.004). The number of diseases/bone-affecting diseases, use of vitamin D/calcium supplementation, use of corticosteroids, smoking or alcohol use had no statistical significance for annual bone loss rate. This study presents hitherto the longest (25-year) BMD follow-up in postmenopausal women. The linear femoral neck bone loss of 10% was less than previously assumed. A 5-year BMD change appeared to predict long-term bone loss in postmenopausal women. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Altered IGF-I activity and accelerated bone elongation in growth plates precede excess weight gain in a mouse model of juvenile obesity

Nearly one-third of children in the United States are overweight or obese by their preteens. Tall stature and accelerated bone elongation are characteristic features of childhood obesity, which cooccur with conditions such as limb bowing, slipped epiphyses, and fractures. Children with obesity paradoxically have normal circulating IGF-I, the major growth-stimulating hormone. Here, we describe and validate a mouse model of excess dietary fat to examine mechanisms of growth acceleration in obesity. We used in vivo multiphoton imaging and immunostaining to test the hypothesis that high-fat diet increases IGF-I activity and alters growth plate structure before the onset of obesity. We tracked bone and body growth in male and female C57BL/6 mice (n = 114) on high-fat (60% kcal fat) or control (10% kcal fat) diets from weaning (3 wk) to skeletal maturity (12 wk). Tibial and tail elongation rates increased after brief (1-2 wk) high-fat diet exposure without altering serum IGF-I. Femoral bone density and growth plate size were increased, but growth plates were disorganized in not-yet-obese high-fat diet mice. Multiphoton imaging revealed more IGF-I in the vasculature surrounding growth plates of high-fat diet mice and increased uptake when vascular levels peaked. High-fat diet growth plates had more activated IGF-I receptors and fewer inhibitory binding proteins, suggesting increased IGF-I bioavailability in growth plates. These results, which parallel pediatric growth patterns, highlight the fundamental role of diet in the earliest stages of developing obesity-related skeletal complications and validate the utility of the model for future studies aimed at determining mechanisms of diet-enhanced bone lengthening.NEW & NOTEWORTHY This paper validates a mouse model of linear growth acceleration in juvenile obesity. We demonstrate that high-fat diet induces rapid increases in bone elongation rate that precede excess weight gain and parallel pediatric growth. By imaging IGF-I delivery to growth plates in vivo, we reveal novel diet-induced changes in IGF-I uptake and activity. These results are important for understanding the sequelae of musculoskeletal complications that accompany advanced bone age and obesity in children.

Adipogenic progenitors in different organs: Pathophysiological implications

In physiological conditions, the adipose organ resides in well-defined areas, where it acts providing an energy supply and as an endocrine organ involved in the control of whole-body energy metabolism. Adipose tissue adipokines connect the body's nutritional status to the regulation of energy balance. When it surrounds organs, it provides also for mechanical protection. Adipose tissue has a complex and heterogenous cellular composition that includes adipocytes, adipose tissue-derived stromal and stem cells (ASCs) which are mesenchymal stromal cells, and endothelial and immune cells, which signal to each other and to other tissues to maintain homeostasis. In obesity and in other nutrition related diseases, as well as in age-related diseases, biological and functional changes of adipose tissue give rise to several complications. Obesity triggers alterations of ASCs, impairing adipose tissue remodeling and adipose tissue function, which induces low-grade systemic inflammation, progressive insulin resistance and other metabolic disorders. Adipose tissue grows by hyperplasia recruiting new ASCs and by hypertrophy, up to its expandability limit. To overcome this limitation and to store the excess of nutrients, adipose tissue develops ectopically, involving organs such as muscle, bone marrow and the heart. The origin of ectopic adipose organ is not clearly elucidated, and a possible explanation lies in the stimulation of the adipogenic differentiation of mesenchymal precursor cells which normally differentiate toward a lineage specific for the organ in which they reside. The chronic exposition of these newly-formed adipose depots to the pathological environment, will confer to them all the phenotypic characteristics of a dysfunctional adipose tissue, perpetuating the organ alterations. Visceral fat, but also ectopic fat, either in the liver, muscle or heart, can increase the risk of developing insulin resistance, type 2 diabetes, and cardiovascular diseases. Being able to prevent and to target dysfunctional adipose tissue will avoid the progression towards the complications of obesity and other nutrition-related diseases. The aim of this review is to summarize some of the knowledge regarding the presence of adipose tissue in particular tissues (where it is not usually present), describing the composition of its adipogenic precursors, and the interactions responsible for the development of organ pathologies.

Muscle plays a more superior role than fat in bone homeostasis: A cross-sectional study of old Asian people

OBJECTIVES

The aim of this study was to discover the role of fat and muscle in bone structures, as well as the relationship between obesity and sarcopenia on age-related osteoporosis.

METHODS

A total of 400 participants (65.0 ± 8.2 years old, 42.3% women) were recruited. Fat, muscle, bone parameters, basic demographics, medical history, physical performance and activity, and calcium intake of participants were obtained from datasets. The diagnosis of osteoporosis, sarcopenia, and obesity was based on current recommendations. Pearson correlation, non-linear regression models, and decision tree analyses were performed to study the relationship between fat, muscle, and bone. Logistic regression analyses were used to explore the risk of osteoporosis in old people with obesity or sarcopenia via Model 1 (unadjusted) and Model 2 (adjusted by age, physical activity, and calcium intake).

RESULTS

Correlation analysis showed that limb muscle mass and index, and age were best related to bone mineral density (BMD) (|r| = 0.386-0.632, p < 0.001). On the contrary, body mass index (BMI) and increased body fat percentage (BF%) were harmful for bone health. An increase of BMI and fat mass index slowed the increase of BMD in the spine, while skeletal muscle mass index accelerated the increase. People with sarcopenia had low muscle mass and strength. When separating subjects into sarcopenia and non-sarcopenia status, sarcopenia was independently related to higher risks of osteoporosis in both models (OR > 1, p < 0.05). BMI-defined obesity in Model 1 as well as BF%-defined obesity in both models did not reduce the risk of osteoporosis in both models (p > 0.05). The decision tree classification (85% accuracy) showed that greater body weight and larger lower limb muscle performance were negatively related to osteoporosis, while fat mass and percentage did not play roles in this prediction.

CONCLUSION

Low muscle mass and function were harmful to bone health. Obesity defined by both BMI and BF% had limited protective roles in osteoporosis. The benefits for bone from increased muscle mass and function play a more superior role than increased fat mass in old people. Sarcopenia prevention and treatment instead of controlling obesity should be recommended as an approach to reduce the risks of age-related osteoporosis and fragility fracture for elderly people.

Saturation Effect of Body Mass Index on Bone Mineral Density in Adolescents of Different Ages: A Population-Based Study

BACKGROUND

Adolescence is a critical period for bone development, and peak bone mass may be reached in late adolescence. Boosting bone accumulation at this time can help preserve adult bone health and avoid osteoporosis later in life. Body mass index (BMI) has been found to have a favorable impact on bone mineral density (BMD) in previous research. However, excessive obesity is harmful to health and may lead to various systemic diseases. Therefore, finding an appropriate BMI to maintain a balance between obesity and BMD is critical for adolescents.

METHODS

The datasets from the National Health and Nutrition Examination Survey (NHANES) 2011-2020 were used in a cross-sectional investigation. Multivariate linear regression models were used to examine the linear connection between BMI and BMD. Fitted smoothing curves and threshold effect analysis were used to describe the nonlinear relationship. Subgroup analyses were then conducted based on gender and age.

RESULTS

This population-based study included a total of 6,143 adolescents aged 8-19 years. In a multivariate linear regression analysis, a good association between BMI and total BMD was shown [0.014 (0.013, 0.014)]. This positive association was maintained in all subgroup analyses grouped by sex and age. Furthermore, the association between BMI and BMD was nonlinear with a saturation point present, as evidenced by smoothed curve fitting. According to the threshold effect study, with an age group of two years, adolescents of different ages had different BMI saturation values with respect to BMD.

CONCLUSIONS

Our study showed a significant positive and saturated association between BMI and BMD in adolescents aged 8-19 years. Maintaining BMI at saturation values may reduce other adverse effects while achieving optimal BMD.

The Influence of Obesity, Ovariectomy, and Greenshell Mussel Supplementation on Bone Mineral Density in Rats

Obesity is considered to impair long-term health by disturbing multiple physiological functions. However, it remains a controversial issue as to whether obesity has beneficial or detrimental effects on bone health in postmenopausal women. The aims of this study were to investigate the relationships between obesity and bone mineral density (BMD) under conditions of ovarian hormone deficiency in an animal model and to evaluate the potential health benefits of Greenshell mussel (GSM) on bone health. A total of 144 adult female Sprague-Dawley rats were fed from age 12 weeks on one of four diets (normal [ND]; ND + GSM; high fat/high sugar [HF/HS]; HF/HS + GSM; n = 36 per diet). At age 20 weeks, after a dual-energy X-ray absorptiometry (DXA) scan, 12 of the rats on each diet underwent ovariectomy (OVX) and the remaining rats were left intact. Twelve of the intact rats in each diet group were culled at age 26 weeks (short-term cohort). The remaining rats were culled at age 48 weeks (long-term cohort). Rats were DXA scanned before cull, then various fat pads were dissected. The results revealed that HF/HS rats and OVX rats dramatically increased body weight and fat deposition in correlation with leptin. In the long-term cohort, vertebral spine BMD rapidly declined after OVX. At termination, the OVX rats had decreased plasma bone turnover markers of CTX-1 and TRAP when compared with sham rats. Significantly higher BMD was found in OVX rats fed the HF/HS diet compared with ND, but this difference was not recapitulated in intact rats. BMD of right femur was significantly increased 5% to 10% by GSM in the short-term cohort. The data demonstrated that obesity can be beneficial by increasing BMD in OVX rats, and this may extrapolate to postmenopausal women as adipocyte-produced estrogen may slightly compensate for the reduction in ovarian hormones. Finally, the data showed that GSM may be beneficial to bone health by increasing BMD accrual. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Bone Response to Weight Loss Following Bariatric Surgery

Obesity is a global health challenge that warrants effective treatments to avoid its multiple comorbidities. Bariatric surgery, a cornerstone treatment to control bodyweight excess and relieve the health-related burdens of obesity, can promote accelerated bone loss and affect skeletal strength, particularly after malabsorptive and mixed surgical procedures, and probably after restrictive surgeries. The increase in bone resorption markers occurs early and persist for up to 12 months or longer after bariatric surgery, while bone formation markers increase but to a lesser extent, suggesting a potential uncoupling process between resorption and formation. The skeletal response to bariatric surgery, as investigated by dual-energy X-ray absorptiometry (DXA), has shown significant loss in bone mineral density (BMD) at the hip with less consistent results for the lumbar spine. Supporting DXA studies, analyses by high-resolution peripheral quantitative computed tomography (HR-pQCT) showed lower cortical density and thickness, higher cortical porosity, and lower trabecular density and number for up to 5 years after bariatric surgery. These alterations translate into an increased risk of fall injury, which contributes to increase the fracture risk in patients who have been subjected to bariatric surgery procedures. As bone deterioration continues for years following bariatric surgery, the fracture risk does not seem to be dependent on acute weight loss but, rather, is a chronic condition with an increasing impact over time. Among the post-bariatric surgery mechanisms that have been claimed to act globally on bone health, there is evidence that micro- and macro-nutrient malabsorptive factors, mechanical unloading and changes in molecules partaking in the crosstalk between adipose tissue, bone and muscle may play a determining role. Given these circumstances, it is conceivable that bone health should be adequately investigated in candidates to bariatric surgery through bone-specific work-up and dedicated postsurgical follow-up. Specific protocols of nutrients supplementation, motor activity, structured rehabilitative programs and, when needed, targeted therapeutic strategies should be deemed as an integral part of post-bariatric surgery clinical support.

Nutrition, Physical Activity, and Dietary Supplementation to Prevent Bone Mineral Density Loss: A Food Pyramid

Bone is a nutritionally modulated tissue. Given this background, aim of this review is to evaluate the latest data regarding ideal dietary approach in order to reduce bone mineral density loss and to construct a food pyramid that allows osteopenia/osteoporosis patients to easily figure out what to eat. The pyramid shows that carbohydrates should be consumed every day (3 portions of whole grains), together with fruits and vegetables (5 portions; orange-colored fruits and vegetables and green leafy vegetables are to be preferred), light yogurt (125 mL), skim milk (200 mL,) extra virgin olive oil (almost 20 mg/day), and calcium water (almost 1 l/day); weekly portions should include fish (4 portions), white meat (3 portions), legumes (2 portions), eggs (2 portions), cheeses (2 portions), and red or processed meats (once/week). At the top of the pyramid, there are two pennants: one green means that osteopenia/osteoporosis subjects need some personalized supplementation (if daily requirements cannot be satisfied through diet, calcium, vitamin D, boron, omega 3, and isoflavones supplementation could be an effective strategy with a great benefit/cost ratio), and one red means that there are some foods that are banned (salt, sugar, inorganic phosphate additives). Finally, three to four times per week of 30-40 min of aerobic and resistance exercises must be performed.

The therapeutic potential of mesenchymal stem cells in treating osteoporosis

Osteoporosis (OP), a common systemic metabolic bone disease, is characterized by low bone mass, increasing bone fragility and a high risk of fracture. At present, the clinical treatment of OP mainly involves anti-bone resorption drugs and anabolic agents for bone, but their long-term use can cause serious side effects. The development of stem cell therapy and regenerative medicine has provided a new approach to the clinical treatment of various diseases, even with a hope for cure. Recently, the therapeutic advantages of the therapy have been shown for a variety of orthopedic diseases. However, these stem cell-based researches are currently limited to animal models; the uncertainty regarding the post-transplantation fate of stem cells and their safety in recipients has largely restricted the development of human clinical trials. Nevertheless, the feasibility of mesenchymal stem cells to treat osteoporotic mice has drawn a growing amount of intriguing attention from clinicians to its potential of applying the stem cell-based therapy as a new therapeutic approach to OP in the future clinic. In the current review, therefore, we explored the potential use of mesenchymal stem cells in human OP treatment.

Obesity and Bone: A Complex Relationship

There is a large literature on the relationship between obesity and bone. What we can conclude from this review is that the increase in body weight causes an increase in BMD, both for a mechanical effect and for the greater amount of estrogens present in the adipose tissue. Nevertheless, despite an apparent strengthening of the bone witnessed by the increased BMD, the risk of fracture is higher. The greater risk of fracture in the obese subject is due to various factors, which are carefully analyzed by the Authors. These factors can be divided into metabolic factors and increased risk of falls. Fractures have an atypical distribution in the obese, with a lower incidence of typical osteoporotic fractures, such as those of hip, spine and wrist, and an increase in fractures of the ankle, upper leg, and humerus. In children, the distribution is different, but it is not the same in obese and normal-weight children. Specifically, the fractures of the lower limb are much more frequent in obese children. Sarcopenic obesity plays an important role. The authors also review the available literature regarding the effects of high-fat diet, weight loss and bariatric surgery.

Metabolic syndrome and fragility fracture risk

INTRODUCTION

The prevalence of metabolic syndrome has been reported to extremely vary depending on the gender, age, and ethnicity studied. Approximately, 25% of the worldwide adult population is affected by metabolic syndrome, indicating it as a significantly important public health challenge. Likewise, fragility fracture represents an important public health issue too, and the lifetime residual risk of its occurrence has been established in 50% in women and 30% in men over 50 years of age, respectively. Dysmobility syndrome summarizes a cluster of co-existing conditions such as osteoporosis, sarcopenia, obesity. Currently, clinical research focuses essentially on the cardiovascular risks associated with metabolic syndrome. Today, it is conceivable to incorporate all these conditions under a generic "disorder of energy metabolism."

EVIDENCE ACQUISITION

Animal and human studies suggest metabolic and dysmobility syndromes negatively impact on the risk for fragility fracture, contributing to increase the associated mortality rate.

EVIDENCE SYNTHESIS

In recent years, strong correlation between type 2 diabetes, a frequent constitutive part of metabolic syndrome and fragility fracture risk has been reported, but the possible molecular mechanisms by which it can occur are still to be defined.

CONCLUSIONS

Only very few human clinical studies faced these aspects, but they lack adequate endpoints for a good clinical practice in these subjects. Much more still needs to be done before appropriate therapeutic diagnostic pathways will be available for these patients at risk of bone and even generalized fragility. Suggestions for a future overall approach by generating global risk score for these conditions are given.

Evaluation of bone metabolism-associated biomarkers in Tibet, China

Aim

To measure and evaluate the distribution and possible contributing factors of seven bone metabolism‐associated biomarkers in Tibet, a plateau province of China.

Methods

A total of 1615 individuals were recruited from Tibet at three different altitudes. The levels and possible contributing factors of serum calcium, serum phosphorus, ALP, 25OHD, PINP, CTX, and PTH were evaluated.

Results

In total, 1246 Tibetan adults (males: n = 543) were eventually enrolled in this study. Multiple linear regression recognized age, sex, altitude, and BMI as the major effect factors. The levels of ALP, PINP, and CTX in males continuously decreased with age; however, those in females increased after approximately 39 years of age. Males had higher 25OHD levels (23.9 vs. 15.4 ng/ml) but lower levels of serum phosphorus (1.12 vs. 1.19 mmol/L) and PTH (41.3 vs. 47.4 pg/ml) than females. Before the age of 50, males had higher levels of calcium, ALP, PINP, and CTX than females, and the opposite trend was observed after the age of 50. The highest levels of serum calcium and phosphorus and the lowest levels of PINP and CTX were found in the Shigatse/Lhasa region, suggesting a better bone metabolism status. Compared with reports from plain areas of China, significantly higher levels of PINP (65.3 vs. 49.36 ng/ml) and CTX (0.46 vs. 0.37 ng/ml) were recorded in Tibetan adults.

Conclusion

A more active bone turnover status was found in Tibetan adults than in individuals from the plain areas of China.

Effects of anthropometric parameters on bone mineral density in women: from perimenopause to old age

AIM

To analyze the influence of body components on bone mineral density (BMD) in women from perimenopause to old age.

MATERIAL AND METHODS

A total of 117 women were allocated into three groups according to the reproductive stage (STRAW): perimenopausal (PEM, N = 28, mean age 44.8 ± 3.6), early postmenopausal (EPM, N = 36, mean age 51.4 ± 2.8) and late postmenopausal (LPM, N = 53; mean age 64.0 ± 1.7). Total body mass, body mass index (BMI), lean mass (LM), fat mass (FM), fat percentage (FP) and BMD at the lumbar spine (lBMD) and femoral neck (fBMD) were assessed.

RESULTS

BMI, FM, LM and BMD values decreased from PEM to LPM. The total effect of FM on fBMD and lBMD was of 42% and 8% for PEM, 28% and 33% for EMP and 9% and 1% for LPM respectively. Additionally, the total effect of LM on fBMD and lBMD was 48% and 3% for PEM, 54% and 53% for EMP and 9% and 11% for LPM women respectively.

CONCLUSION

BMI, LM, and FM decreased with aging. All these components had great influence on both fBMD and lBMD in EMP women. Conversely, in PEM these parameters only had influence on femoral BMD, but not on lumbar spine. These data suggests that LM is the most important component in BMD for women older than 50 years old, particularly in the hip.

Lower trabecular bone score in type 2 diabetes mellitus: A role for fat mass and insulin resistance beyond hyperglycaemia

AIMS

To examine the clinical and biochemical determinants of trabecular bone score (TBS) in type 2 diabetes mellitus (T2DM) patients.

METHODS

Cross-sectional observational study in 137 T2DM patients (49-85 years). Whole-body fat percentage was estimated using the relative fat mass (RFM) equation. Bone mineral density (BMD) and TBS were assessed using dual-energy X-ray absorptiometry and TBS iNsight Software respectively.

RESULTS

T2DM patients showed significantly lower TBS values (P < 0.001) despite significantly higher lumbar spine BMD (LS-BMD) (P = 0.025) compared to controls. TBS values ​​were negatively correlated with body mass index (BMI) (P < 0.001), waist circumference (P < 0.001), and HOMA-2IR index (P = 0.004) and positively correlated with sex hormone-binding globulin (SHBG) (P = 0.01) and LS-BMD (P = 0.003). RFM was negatively associated with TBS in both males (P < 0.001) and females (P = 0.005). The multivariate analysis showed that RFM, HOMA2-IR (negative), SHBG, and LS-BMD (positive) were the variables independently associated with TBS. ROC analysis revealed RFM as the variable with the highest predictive value for risk of degraded bone microarchitecture.

CONCLUSIONS

The adiposity estimated by RFM may negatively affect TBS and this relationship may be influenced by insulin resistance and SHBG. RFM could act as a key estimator of degraded bone microarchitecture risk in the T2DM population.

Serum Metabolite Profile Associated with Sex-Dependent Visceral Adiposity Index and Low Bone Mineral Density in a Mexican Population

Recent evidence shows that obesity correlates negatively with bone mass. However, traditional anthropometric measures such as body mass index could not discriminate visceral adipose tissue from subcutaneous adipose tissue. The visceral adiposity index (VAI) is a reliable sex-specified indicator of visceral adipose distribution and function. Thus, we aimed to identify metabolomic profiles associated with VAI and low bone mineral density (BMD). A total of 602 individuals from the Health Workers Cohort Study were included. Forty serum metabolites were measured using the targeted metabolomics approach, and multivariate regression models were used to test associations of metabolomic profiles with anthropometric, clinical, and biochemical parameters. The analysis showed a serum amino acid signature composed of glycine, leucine, arginine, valine, and acylcarnitines associated with high VAI and low BMD. In addition, we found a sex-dependent VAI in pathways related to primary bile acid biosynthesis, branched-chain amino acids, and the biosynthesis of pantothenate and coenzyme A (CoA). In conclusion, a metabolic profile differs by VAI and BMD status, and these changes are gender-dependent.

Hemoglobin and adult height loss among Japanese workers: A retrospective study

Height loss starting in middle age is reported to be associated with increased all-cause and cardiovascular mortality later in life. However, the mechanisms underlying this association are unclear. Hypoxia and oxidative stress, which are known causes of cardiovascular disease, could be reduced by hemoglobin. Therefore, hemoglobin could be inversely associated with height loss. However, high body mass index (BMI) is a known risk factor for intervertebral disc disorder, a known cause of height loss in adults. High BMI might confound the association between hemoglobin and height loss. Therefore, we performed analyses stratified by BMI status. To clarify the association between hemoglobin and height loss, we conducted a retrospective study of Japanese workers (6,471 men and 3,180 women) aged 40–74 years. Height loss was defined as being in the highest quintile of height decrease per year. In men overall and men with BMI <25 kg/m², hemoglobin was significantly inversely associated with height loss; but no association was observed for men with high BMI (BMI ≥25 kg/m²) and for women. For men, after adjusting for known cardiovascular risk factors, adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for height loss with each 1 standard deviation (SD) increase in hemoglobin (1.0 g/dL for men and 0.8g/dL for women) were 0.89 (0.83, 0.95) for men overall, 0.82 (0.75, 0.89) for men who do not have high BMI, and 1.01 (0.92, 1.12) for men with high BMI. For women, the corresponding values were 0.97 (0.89, 1.06), 0.98 (0.89, 1.09), and 0.93 (0.75, 1.15) respectively. Hemoglobin is significantly inversely associated with height loss in men who do not have high BMI, but not in men with high BMI or women. These results help clarify the mechanisms underlying height loss, which has been reported to be associated with a higher risk of mortality in adults.

Obesity paradox and heart failure

BACKGROUND

There is scientific consensus that obesity increases the risk of cardiovascular diseases (CVD), including heart failure (HF). However, in CVD, many studies observed greater survival in overweight or class 1 obesity individuals. This counterintuitive observation was termed "obesity paradox" (OP).

OBJECTIVE AND METHODS

This article is a narrative overview of the relationship between OP and CVD, particularly HF. The sources used were MEDLINE/PubMed, CINAHL, EMBASE, and Cochrane Library, from 2001 to 31 May 2020, exception for a 1983 work of historical importance. Studies reporting association and prognostic impact of obesity in HF and the impact of body composition on cardiac structure and myocardial function in obesity were also included in this review. In addition, we examined references from the retrieved articles and explored several related websites. Ultimately, we chose 79 relevant documents. Fifty-three were specifically focused on OP and HF.

RESULTS

In this review, we made a summary of the evidence coming from a series of studies investigating OP. Many of these studies do not take into consideration or underestimate some of the more important morpho-functional variables of patients suffering from HF: among these, body composition and visceral adiposity, sarcopenic obesity, muscle fitness (MF), and cardiorespiratory fitness (CRF). A high body mass index (BMI) represents a risk factor for HF, but it also seems to exert a protective effect under certain circumstances. Fat distribution, lean mass, and cardio fitness could play an essential role in determining the observed differences in the HF population.

CONCLUSION

BMI does not distinguish between the metabolically healthy and metabolically unhealthy obesity. The obesity impact on morbidity and premature mortality can be underestimated and, therefore, may lead to incorrect clinical courses.

LEVEL OF EVIDENCE

Level V, Narrative review.

Association between obesity and risk of fracture, bone mineral density and bone quality in adults: A systematic review and meta-analysis

BACKGROUND

The association between obesity and fracture risk may be skeletal site- and sex-specific but results among studies are inconsistent. Whilst several studies reported higher bone mineral density (BMD) in patients with obesity, altered bone quality could be a major determinant of bone fragility in this population.

OBJECTIVES

This systematic review and meta-analysis aimed to compare, in men, premenopausal women and postmenopausal women with obesity vs. individuals without obesity: 1) the incidence of fractures overall and by site; 2) BMD; and 3) bone quality parameters (circulating bone turnover markers and bone microarchitecture and strength by advanced imaging techniques).

DATA SOURCES

PubMed (MEDLINE), EMBASE, Cochrane Library and Web of Science were searched from inception of databases until the 13th of January 2021.

DATA SYNTHESIS

Each outcome was stratified by sex and menopausal status in women. The meta-analysis was performed using a random-effect model with inverse-variance method. The risks of hip and wrist fracture were reduced by 25% (n = 8: RR = 0.75, 95% CI: 0.62, 0.91, P = 0.003, I2 = 95%) and 15% (n = 2 studies: RR = 0.85, 95% CI: 0.81, 0.88), respectively, while ankle fracture risk was increased by 60% (n = 2 studies: RR = 1.60, 95% CI: 1.52, 1.68) in postmenopausal women with obesity compared with those without obesity. In men with obesity, hip fracture risk was decreased by 41% (n = 5 studies: RR = 0.59, 95% CI: 0.44, 0.79). Obesity was associated with increased BMD, better bone microarchitecture and strength, and generally lower or unchanged circulating bone resorption, formation and osteocyte markers. However, heterogeneity among studies was high for most outcomes, and overall quality of evidence was very low to low for all outcomes.

CONCLUSIONS

This meta-analysis highlights areas for future research including the need for site-specific fracture studies, especially in men and premenopausal women, and studies comparing bone microarchitecture between individuals with and without obesity.

SYSTEMATIC REVIEW REGISTRATION NUMBER

CRD42020159189.

A pilot screening study for low bone mass in Singaporean women using years since menopause and BMI

OBJECTIVE

Current risk assessment tools for osteoporosis have inconsistent performance across different cohorts, making them difficult for clinical practice. This study aimed to evaluate a simple screening index comprising years since menopause (YSM) and body mass index (BMI) that identifies postmenopausal Singaporean women with a greater likelihood of low bone mass.

METHODS

The study used data from 188 treatment-naïve postmenopausal women. The associations between low bone mass and different demographic variables, including age, YSM and BMI, were assessed using multivariable logistic regression. Diagnostic performance of the calculated screening index was compared to the Osteoporosis Self-Assessment Tool for Asians (OSTA) and the Fracture Risk Assessment Tool (FRAX^®).

RESULTS

YSM and BMI were significantly associated with low bone mass. The area under the receiver operating characteristic curves was 0.803 for the screening index, 0.759 for the OSTA, 0.683 for the FRAX^® (major osteoporotic fracture probability [MOFP]) and 0.647 for the FRAX^® (hip fracture probability [HFP]). Non-parametric Spearman's correlation between the screening index and the other models was 0.857 with the OSTA score, 0.694 with the FRAX^® (HFP) and 0.565 with the FRAX^® (MOFP) (p < 0.0005).

CONCLUSIONS

The diagnostic performance of the screening index comprising YSM and BMI was equivalent to the OSTA and the FRAX^®. A risk chart was developed for clinicians to identify and recommend subjects for a further dual-energy X-ray absorptiometry scan. Validation of this model in larger and more diverse cohorts is required.

In Men With Obesity, T2DM Is Associated With Poor Trabecular Microarchitecture and Bone Strength and Low Bone Turnover

INTRODUCTION

Obesity and type 2 Diabetes (T2D) are both associated with greater bone mineral density (BMD) but increased risk of fractures. The effect of the combination of both conditions on bone metabolism, microarchitecture, and strength in the obese population remains unknown.

METHODS

Data from 112 obese men were collected. Bone turnover and biochemical markers were measured by enzyme-linked immunosorbent assay, body composition and BMD at all sites were assessed by dual energy X-ray absorptiometry, whereas bone microarchitecture and strength (stiffness and failure load) were measured by high-resolution peripheral computed tomography. Data were compared among metabolically healthy obese (MHO) and metabolically unhealthy obese (MUHO) with and without T2D and between obese without and with T2D.

RESULTS

Compared to MHO and MUHO without T2D, MUHO with T2D had significantly lower levels of osteocalcin ((7.49 ± 3.0 and 6.03 ± 2.47 vs 4.24 ± 2.72 ng/mL, respectively, P = 0.003) and C-terminal telopeptide of type I collagen (CTx) (0.28 ± 0.10 and 0.29 ± 0.13 vs 0.21 ± 0.15 ng/mL, respectively, P = 0.02). Dividing our subjects simply into those with and without T2D showed that obese men with T2D had significantly lower levels of osteocalcin (P = 0.003) and CTx (P = 0.005), greater trabecular separation at the tibia and radius (P = 0.03 and P = 0.04, respectively), and lower tibial failure load and stiffness (both P = 0.04), relative to obese men without T2D.

CONCLUSION

In men, the combination of obesity and T2D is associated with reduced bone turnover and poorer trabecular bone microarchitecture and bone strength compared to those who are obese but without T2D, suggesting worse bone disease.

Influence of weight status on bone mineral content measured by DXA in children

INTRODUCTION

Childhood obesity is a public health problem with repercussions in later life. As tissue formation peaks in childhood we determined how weight status influences bone mineral content.

MATERIAL AND METHODS

We studied 553 children aged 4-18 years over 10 years (46.8% girls). We measured age, weight, height and through bone densitometry (DXA), bone mineral content (BMC), bone mineral density (BMD), and waist, arm and hip circumferences. The patients were divided into groups using the body mass index z-score: underweight, normal weight, overweight, obese and very obese.

RESULTS

BMC and BMD values were highest in the normal-weight and overweight groups. Logistic regression showed bone mineralization was inversely associated with waist circumference, the association being positive for weight and age. No differences were found according to sex.

DISCUSSION

Studies of the relationship between weight and bone mineralization report contradictory results, often because of different study designs. Moreover, studies in children are either few or with small samples. Our findings in a large sample show the importance of weight status in bone mineralization given the risk of bone fractures or osteoporosis.

CONCLUSIONS

Weight status influenced bone mineralization. BMC and BMD decreased in children with a higher degree of obesity. Waist circumference correlated negatively with bone mineralization.

Evaluation of the Efficacy of Transdermal and Injection Testosterone Therapy in Klinefelter Syndrome: A Real-Life Study

Context

Klinefelter Syndrome (KS) is the most frequent sex chromosome disorder in males. Due to hypergonadotropic hypogonadism, treatment with testosterone replacement therapy (TRT) is commonly indicated. There are no international guidelines for the most appropriate TRT in KS.

Objective

We aimed to evaluate how different routes of testosterone administration impact testosterone-responsive variables, as well as the development of later metabolic diseases and other complications.

Methods

We conducted a retrospective study covering 5 years from 2015 to 2020. Data on TRT, biochemical parameters, bone mineral density (BMD), medications, comorbidity, and karyotyping were derived from electronic patient records and The Danish Cytogenetic Register.

Results

A total of 147 KS males were included: 81 received injection TRT, 61 received transdermal TRT, and 5 did not receive TRT. Testosterone levels were similar in the 2 TRT groups (P = 0.9), while luteinizing hormone and follicle-stimulating hormone levels were higher in the group receiving transdermal TRT (P = 0.002). Levels of cholesterol, blood glucose, hemoglobin A1c, hemoglobin, hematocrit, liver parameters, prostate-specific antigen, and spine and hip BMD were similar in the 2 treatment groups (Ps > 0.05).

Conclusion

TRT, irrespective of route of administration, affects androgen-responsive variables similarly in males with KS. Neither long-acting injection nor transdermal gel seem to reduce the risk of metabolic diseases significantly. These results should encourage clinicians in seeking the route of administration resulting in the highest degree of adhesion to treatment based on individual patient preferences. Implementation of shared decision-making with patients may be important when choosing TRT.

Association between geriatric nutrition risk index and bone mineral density in elderly Chinese people

Malnutrition contributes to the occurrence of osteoporosis. This study showed that participants with higher GNRI values had higher levels of BMD. GNRIs were positively correlated with BMD and independently associated with total hip T-score. GNRIs may be a good indicator for identifying elderly who need further bone health nutritional support.

PURPOSE

To evaluate the relationship between geriatric nutrition risk index (GNRI) and bone mineral density (BMD) in elderly Chinese people.

METHODS

We recruited 1130 older adults (60-89 years old) between May 2018 and December 2019. Participants underwent clinical, laboratory, and densitometry examinations. Dual-energy x-ray absorptiometry densitometers and corresponding software were used to assess the BMD and T-scores of participants. Differences between study groups were assessed using one-way analysis of variance (ANOVA) for continuous variables and the chi-square test for categorical variables. Pearson's correlation coefficient was used to assess the correlation between two variables. Multivariate linear regressions with or without adjustments were constructed to explore the possible confounding variables.

RESULTS

Individuals with higher GNRI values had higher total hip and lumbar spine T-scores (P < 0.001, P = 0.029, respectively). Pearson's correlation demonstrated that GNRIs were positively correlated with BMD at different anatomical sites, in both sexes but especially in women. A multiple regression demonstrated that GNRIs were independently associated with total hip T-score in both sexes (β = 0.111 for men and 0.174 for women; P = 0.034 and 0.008, respectively).

CONCLUSIONS

Elderly people with higher GNRI values had higher total hip and lumbar spine T-scores, which suggested that GNRI is closely related to BMD. This relationship is maintained at the total hip, even after fully adjusting for possible confounding variables, and consequently, it may be a good indicator for identifying older people who need further bone health nutritional support.

Prevalence and diagnosis experience of osteoporosis in postmenopausal women over 50: Focusing on socioeconomic factors

Osteoporosis is the most common disease of the musculoskeletal system in old age. Therefore, research on osteoporosis risk factors is actively being conducted. However, whether socioeconomic inequality is associated with the prevalence and diagnosis experience of osteoporosis remains largely unexplored. This study aims to investigate whether socioeconomic inequality can be a risk factor for osteoporosis in postmenopausal women. Cross-sectional data of 1,477 postmenopausal women aged over 50 obtained from the Korea National Health and Nutrition Examination Survey V-2 were analyzed. Univariate analyses were performed to calculate the prevalence of osteoporosis and the rate of osteoporosis diagnosis experience according to the risk factor categories. Multivariate logistic regression analysis was performed to identify the independent variables' associations with osteoporosis prevalence and diagnosis experience. The prevalence of osteoporosis was 34.8%, while the diagnosis experience rate was 22.1%. The higher the age, the higher the probability of osteoporosis presence and diagnosis experience. The lowest household income level was associated with a 1.63 times higher risk of osteoporosis. On the contrary, this factor was not significant for diagnosis experience. These results were similar for the 50-59 and 60-69 age groups. Among postmenopausal women, those who are older and have low socioeconomic levels are at a high risk of developing osteoporosis. Moreover, the lower the socioeconomic level, the lower the awareness of osteoporosis. Therefore, there is a need to develop more proactive preventive measures in postmenopausal women with low socioeconomic levels.

The relationship between healthy lifestyles and bone health: A narrative review

BACKGROUND

Bone health, especially osteoporosis among ageing populations, has become an important topic for both clinical and basic researchers. The relationship between bone health and healthy lifestyles has been frequently discussed. The present study focuses on the relationship between bone health and healthy lifestyles among older adults, based on a global comparison.

METHODS

This narrative review was performed by collecting clinical trials, basic research and reviews on lifestyle and bone health in PubMed database.

RESULTS

Positive effects of physical activity and negative effects of malnutrition, alcohol abuse, and cigarette smoking on bone health were revealed. The relationship between bone health and drinking coffee and tea is still inconclusive. Moreover, the diversity of each region should be aware when considering healthy lifestyles to improve bone health.

CONCLUSION

Healthy lifestyles are highly related to bone health, and different lifestyles may have different influences on regions with a high risk of bone diseases. It is practical to acknowledge the diversity of economic, religious, environmental and geological conditions in each region when providing suitable and effective recommendations for healthy lifestyles that can improve overall bone health.

Association between fractures and traditional risk factors for osteoporosis and low bone mineral density in patients with obesity

Objective

To evaluate the reasons for request of bone mineral density (BMD) evaluation and correlate the BMD results with previous fractures, risk factors for osteoporosis, and clinical characteristics in patients with obesity.

Methods

Cross-sectional, retrospective, single-site study including adult patients with body mass index (BMI) ≥ 30 kg/m² and BMD evaluation between January 2015 and May 2016 selected from a BMD database. Data on demographic characteristics, lifestyle habits, comorbidities, medications, risk factors, previous fractures, and indications for BMD evaluation were collected from the participants' medical records.

Results

The study included 619 patients (89.9% women, mean BMI 34.79 ± 4.05 kg/m²). In all, 382 (61.7%), 166 (26.8%), and 71 (11.5%) patients had class 1, 2, and 3 obesity, respectively. The most frequent (29.9%) reason for BMD evaluation was for osteoporosis monitoring. In all, 69.4% of the patients had low BMD. Multivariate analysis showed that age, calcium supplementation, and previous osteoporosis or osteopenia were associated with low BMD, while age, vitamin D supplementation, use of proton pump inhibitors (PPIs), and low BMD were associated with previous fractures (p < 0.05 for all).

Conclusion

Among patients with obesity identified from a tertiary hospital database, those with low bone mass and risk factors traditionally associated with fractures had an increased history of fractures. Patients with greater BMI had better bone mass and fewer fractures. These findings indicate that the association between reduced weight, risk factors for osteoporosis, and fractures remained despite the presence of obesity in our population.

Bone loss markers in the earliest Pacific Islanders

Kingdom of Tonga in Polynesia is one of the most obese nations where metabolic conditions, sedentary lifestyles, and poor quality diet are widespread. These factors can lead to poor musculoskeletal health. However, whether metabolic abnormalities such as osteoporosis occurred in archaeological populations of Tonga is unknown. We employed a microscopic investigation of femur samples to establish whether bone loss afflicted humans in this Pacific region approximately 3000 years ago. Histology, laser confocal microscopy, and synchrotron Fourier-transform infrared microspectroscopy were used to measure bone vascular canal densities, bone porosity, and carbonate and phosphate content of bone composition in eight samples extracted from adult Talasiu males and females dated to 2650 BP. Compared to males, samples from females had fewer vascular canals, lower carbonate and phosphate content, and higher bone porosity. Although both sexes showed evidence of trabecularised cortical bone, it was more widespread in females (35.5%) than males (15.8%). Our data suggest experiences of advanced bone resorption, possibly as a result of osteoporosis. This provides first evidence for microscopic bone loss in a sample of archaeological humans from a Pacific population widely afflicted by metabolic conditions today.

Bone health in idiopathic inflammatory myopathies

OBJECTIVE

To review the extant literature relating to bone health in the idiopathic inflammatory myopathies (IIM) including both adult and juvenile patients.

METHODS

A PubMed search® identified relevant studies from 1966 to 2020 in accordance with PRISMA guidelines. Two independent reviewers screened and extracted the abstracts/full manuscripts, and a third author was consulted in the case of disagreement.

RESULTS

We identified 37 articles (3 review articles, 2 RCTs, 9 cross-sectional, 16 cohort and 7 case-control studies). The prevalence of osteopenia (n = 7) ranges from 7 to 75% and osteoporosis (n = 7) between 13% to 27%. The prevalence of vertebral fractures ranged from 11 to 75%. Systemic inflammation likely contributes to reduced bone mineral density (BMD) in children with IIM but data is currently lacking in adult patients. Association between with impaired BMD and Vitamin D or calcium intake and physical activity has not been demonstrated in IIM. There is no clear consensus regarding the impact of age, menopause or BMI on bone health. Gender, smoking status, disease activity and inflammatory markers are not obvious independent predictors of low BMD. Several studies have demonstrated that glucocorticoids are associated with an increased risk of low BMD. There are no specific guidelines relating to the management of bone health in adult and juvenile patients with IIM.

CONCLUSION

Both adult and juvenile patients with IIM are at high risk of impaired bone health and fracture. The mechanisms behind this are likely multifactorial including systemic inflammation, glucocorticoid treatment, reduced mobility and impaired calcium/vitamin D homeostasis. There are a lack of guidelines and studies relating to the screening, prevention and treatment of impaired bone health in adult and juvenile patients with IIM. Future research is required to understand the complexity of bone health in IIM including to develop much needed disease-specific management recommendations.

Obesity paradox and aging

BACKGROUND

In association with the rapid lengthening of life expectancy and the ever-rising prevalence of obesity, many studies explored in the elderly the phenomenon usually defined as the obesity paradox.

OBJECTIVE AND METHODS

This article is a narrative overview of seventy-two papers (1999-2019) that investigated the obesity paradox during the aging process. Twenty-nine documents are examined more in detail.

RESULTS

The majority of studies suggesting the existence of an obesity paradox have evaluated just BMI as an index of obesity. Some aspects are often not assessed or are underestimated, in particular body composition and visceral adiposity, sarcopenic obesity, and cardio fitness. Many studies support that central fat and relative loss of fat-free mass may become relatively more important than BMI in determining the health risk associated with obesity in older ages.

CONCLUSION

Inaccurate assessments may lead to a systematic underestimation of the impact of obesity on morbidity and premature mortality and, consequently, to clinical behaviors that are not respectful of the health of elderly patients. Knowledge of the changes in body composition and fat distribution will help to better understand the relationship between obesity, morbidity, and mortality in the elderly.

LEVEL OF EVIDENCE

Level V, narrative overview.

Lycium barbarum polysaccharide (LBP) inhibits palmitic acid (PA)-induced MC3T3-E1 cell apoptosis by regulating miR-200b-3p/Chrdl1/PPARγ

Background

Obesity is closely related to osteoporosis. Lycium barbarum polysaccharides (LBPs) have anti-osteoporosis activity.

Objective

This study aimed to explore the role of LBPs in palmitic acid (PA)-induced osteoblast apoptosis.

Methods

The microarray data set GSE37676 was downloaded from Gene Expression Ominibus (GEO) database. Top 300 differentially expressed genes (DEGs) were used to construct a protein–protein interaction (PPI) network based on STRING database, and significant modules were analyzed and their key genes were screened by using Cytoscape software. COEXPEDIA database showed that there was co-expression between Chrdl1 and peroxisome proliferator-activated receptor (PPARγ). MC3T3-E1 cells were treated with 100–500 μg/mL of PA. Reverse transcription polymerase chain reaction (RT-PCR) and western blot assays were used to detect mRNA and protein levels. Cell Counting Kit-8 (CCK-8) assay and flow cytometry were used to detect cell viability and cell apoptosis.

Results

Chrdl1 was the key gene from the most significant module and downregulation in MC3T3-E1 cells treated with PA. MicroRNA miR-200b-3p and PPARγ were significantly upregulated among PA-treated MC3T3-E1 cells. The results of luciferase reporter gene assay showed that miR-200b-3p targeted Chrdl1 3’-UTR. Over-expressing miR-200b-3p promoted PA-induced cell apoptosis and inhibited cell viability. After pre-treating cells with PA and LBP, MC3T3-E1 cell apoptosis rate was relatively lower than that of mimics+PA₂₀₀ group. Chrdl1 inhibition partly reversed miR-200b-3p effect on inhibiting apoptosis among MC3T3-E1 cells pre-treated with LBP and PA. Decreased C CASP3, PPARγ and increased Chrdl1 by miR-200b-3p inhibition were partly reversed by Chrdl1 inhibition.

Conclusions

LBPs inhibit PA-induced MC3T3-E1 cell apoptosis by mainly decreasing miR-200b-3p to upregulate Chrdl1, but miR-200b-3p/Chrdl1/PPARγ is not the only mechanism for LBPs protecting osteoblasts from PA.

The Interaction of Lean Body Mass With Fat Body Mass Is Associated With Vertebral Fracture Prevalence in Women With Early Breast Cancer Undergoing Aromatase Inhibitor Therapy

Aromatase inhibitors (AIs) induce depletion of estrogen levels, causing bone loss and increased fracture risk in women with breast cancer. High‐fat body mass (FBM) emerged as an independent factor associated with the prevalence of morphometric vertebral fractures (VFs) in patients undergoing AIs. We explored the role of lean body mass (LBM) and the interaction of LBM with FBM in predicting the occurrence of VFs in postmenopausal women who were either AI‐naïve or AI‐treated. A total of 684 consecutive breast cancer patients were enrolled in this cross‐sectional study. Each woman underwent a dual‐energy X‐ray absorptiometry (DXA) scan, measuring bone mineral density (BMD), LBM, and FBM; VFs were assessed using a quantitative morphometric analysis of DXA images. After propensity score matching, the study population was restricted to 480 women, 240 AI‐naïve and 240 AI‐treated. We used multivariable logistic regression models to explore the associations between baseline characteristics, VF prevalence and the interaction between LBM, FBM and AI therapy. No interaction between LBM and AI therapy on VF prevalence was shown. Conversely, we reported a significant interaction between LBM, FBM and AI therapy (p = .0311). Among AI‐treated women having LBM below and FBM above or equal the median value, VF prevalence was numerically higher (15/31; 48.4%) than in other subgroups (VF prevalence: 35.7% in high‐LBM and low‐FBM group, 23.2% in high‐LBM and high‐FBM group, and 19.8% in low‐LBM and low‐FBM group). Among AI‐naïve women, the greatest VF proportion was observed in the subgroup with LBM and FBM below median value (25/92; 27.2%). This study suggests a synergism between LBM and FBM in predicting the morphometric VF in women with early breast cancer undergoing AIs. This observation is new and deserves further investigation. The assessment of body composition by DXA might be useful when estimating fracture risk in this population. © 2020 American Society for Bone and Mineral Research © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Obesity and Bone Health: A Complex Link

So far, the connections between obesity and skeleton have been extensively explored, but the results are inconsistent. Obesity is thought to affect bone health through a variety of mechanisms, including body weight, fat volume, bone formation/resorption, proinflammatory cytokines together with bone marrow microenvironment. In this review, we will mainly describe the effects of adipokines secreted by white adipose tissue on bone cells, as well as the interaction between brown adipose tissue, bone marrow adipose tissue, and bone metabolism. Meanwhile, this review also reviews the evidence for the effects of adipose tissue and its distribution on bone mass and bone-related diseases, along with the correlation between different populations with obesity and bone health. And we describe changes in bone metabolism in patients with anorexia nervosa or type 2 diabetes. In summary, all of these findings show that the response of skeleton to obesity is complex and depends on diversified factors, such as mechanical loading, obesity type, the location of adipose tissue, gender, age, bone sites, and secreted cytokines, and that these factors may exert a primary function in bone health.