Obesity: Friend or foe for osteoporosis

Synergic Action of Systemic Risedronate and Local Rutherpy in Peri-implantar Repair of Ovariectomized Rats: Biomechanical and Molecular Analysis

Postmenopausal osteoporosis and poor dietary habits can lead to overweightness and obesity. Bisphosphonates are the first-line treatment for osteoporosis. However, some studies show that they may increase the risk of osteonecrosis of the jaw. Considering the antimicrobial, angiogenic and vasodilatory potential of nitric oxide, this study aims to evaluate the local activity of this substance during the placement of surface-treated implants. Seventy-two Wistar rats were divided into three groups: SHAM (SHAM surgery), OVX + HD (ovariectomy + cafeteria diet), and OVX + HD + RIS (ovariectomy + cafeteria diet + sodium risedronate treatment), which were further subdivided according to the surface treatment of the future implant: CONV (conventional), TE10, or TE100 (TERPY at 10 or 100 μM concentration); n = 8 per subgroup. The animals underwent surgery for implant installation in the proximal tibia metaphysis and were euthanized after 28 days. Data obtained from removal torque and RT-PCR (OPG, RANKL, ALP, IBSP and VEGF expression) were subjected to statistical analysis at 5% significance level. For biomechanical analysis, TE10 produced better results in the OVX + HD group (7.4 N/cm, SD = 0.6819). Molecular analysis showed: (1) significant increase in OPG gene expression in OVX groups with TE10; (2) decreased RANKL expression in OVX + HD + RIS compared to OVX + HD; (3) significantly increased expressions of IBSP and VEGF for OVX + HD + RIS TE10. At its lowest concentration, TERPY has the potential to improve peri-implant conditions.

Associations Between Body Mass Index, WNT16 rs2908004 and Osteoporosis: Findings from Taiwan Biobank

Purpose

Osteoporosis is a degenerative disease that affects women and men of all races. We studied the association between body mass index (BMI), rs2908004 polymorphism of the WNT16 gene, and osteoporosis using data from Taiwan Biobank (TWB).

Patients and Methods

We analyzed data from 10,942 subjects aged 30 to 70. We defined osteoporosis based on a mean T-score of -2.5 and below in the hip. Body mass index was classified following the guidelines of the Health Promotion Administration. Imputation was carried out using the IMPUTE2 (v2.3.1) program. Multiple logistic regression was used for analysis. The odds ratios (ORs) and 95% confidence interval (CI) for osteoporosis were determined.

Results

In the multivariate regression model, variant rs2908004 had a significant association with osteoporosis. That is, the rs2908004-GA+AA genotype was associated with lower osteoporosis risk than the GG genotype (OR, 0.651; 95% CI = 0.544 to 0.780). Compared to normal-weight, underweight was significantly associated with a higher risk of osteoporosis (OR, 6.517; 95% CI = 4.624 to 9.186) while overweight and obesity were protective (OR, 0.176; 95% CI = 0.140 to 0.221 and 0.057; 95% CI = 0.039 to 0.083, respectively). There was an interaction between rs2908004 and BMI (p = 0.0148). Subgroup analyses (using rs2908004-GG/normal-weight as the reference group) indicated ORs of 7.66 (95% CI = 5.153 to 11.394) in the rs2908004-GG/underweight group and 3.002 (95% CI = 1.509 to 5.974) in the rs2908004-GA+AA/underweight group (95% CI = 1.509 to 5.974). Odds ratios were substantially lower in rs2908004-GG/obese, rs2908004-GG/overweight, GA+AA/normal-weight, rs2908004-GA+AA/overweight, and rs2908004-GA+AA/obese groups, respectively.

Conclusion

According to our study, underweight was associated with an increased risk of osteoporosis irrespective of WNT16 rs2908004 genotypes, while overweight and obesity were associated with a lower risk.

Risk Factors of Osteoporosis in Females: A Hospital-Based Case-Control Study, Yazd, Iran

BACKGROUND

The aim of this study was to evaluate the predictors of osteoporosis in women in Yazd, Iran.

METHODS

This hospital-based case-control study was performed on 270 women 35-65 yr old (135 case and 135 control) from Mar 2016 to Mar 2017. Case and control were matched in terms of age ± 2 (year) as a group matching. Osteoporosis is defined as a T-score of bone mineral density (BMD) below -2.5 SD. Data were analyzed using SPSS 20 software. Statistical tests included chi-square, student t test and Mann Whitney test .Multiple logistic regression (MLR) which forward method was used for modeling.

RESULTS

Odds ratio (OR) of osteoprosis were menarche age>12 yr (OR=3.37, CI:2.29-15.89), history of hysterectomy (OR=13, CI:3.81-44.82), rheumatoid arthritis (RA) (OR=6.58, CI:2.29-18.91) calcium supplements (OR=0.14, CI:0.04-0.41), menopause age <40 (OR=11.84, CI:1.54-90), second smoking (OR=3.38, CI:1.16-9.81) and increase of weight (OR=0.86, CI:0.80-0.94).

CONCLUSION

Predictors of osteoporosis was menarche age >12 yr (3 times), history of hysterectomy (13 times), RA (6.5 times), menopause age <40 (12 times), second smoking (more than 3 times), calcium supplements and weight (protective).

The Relationship Between Bone Mineral Density and Body Composition Among Qatari Women With High Rate of Obesity: Qatar Biobank Data

Studies have reported inconsistent results for the relationship between body composition and bone mineral density (BMD) among women, especially those with a high rate of obesity. This study aims to examine the association between BMD and body composition among Qatari women. A cross-sectional study, using data from the Qatar Biobank (QBB), was conducted on 2,000 Qatari women aged 18 and over. Measurements were taken by dual-energy X-ray absorptiometry (DEXA) for body composition [visceral fat and android fat (AF)], gynoid fat (GF), trunk fat, total fat mass (TFM), total lean mass (LM) and bone mineral density (BMD), including the lumber spine, neck, femur and total body. The participants were divided into groups of normal and low BMD, based on their T-score. Non-linear regression analysis using the restricted cubic spline method was performed according to the T-score of the total BMD for the fat mass variables. Women with a low BMD (T-score <-1) had significantly lower body composition indicators. LM was positively correlated with BMD at the spine (r = 0.29, p < 0.001), neck (r = 0.32, p < 0.001), and femur (r = 0.28, p < 0.001), as well as total BMD (r = 0.29, p < 0.001) and T-score (r = 0.31, p < 0.001), while the correlatio between TFM and BMD was negative and weak (r = -0.05, <0.017). Results of the non-linear regression indicated that components of fat distribution (TFM, AF, GF and trunk fat) were positively associated with total body T-score. In the adjusted non-liner regression, only a slight increase in T-score was recorded with an increase in FM. The association between FM and BMD was non-linear, suggesting that FM may not be a strong protector of bones among women with high rate of obesity.

Weight Change Is Associated with Osteoporosis: A Cross Sectional Study Using the Korean Community Health Survey

The purpose of the present study was to analyze the associations between weight change and osteoporosis in Korean adults. Methods: Data from the 2016 Korean Community Health Survey were analyzed. A total of 159,741 participants who were ≥40 years of age were included. The histories of osteoporosis were surveyed in two ways: ‘osteoporosis for entire life’ and ‘current osteoporosis’. The participants were grouped into three categories for simplification as follows: ‘Weight L&M’ (Tried to lose weight or Tried to maintain weight), ‘Weight gain’ (Tried to gain weight), and ‘Never tried’. Additionally, we analyzed their relationship with obesity using the BMI. Results: The adjusted ORs for ‘osteoporosis for entire life’ were 1.20 (95% confidence interval [CI] 1.13–1.27) in the Weight L&M group and 1.83 (95% CI 1.64–2.05) in the Weight gain group. The adjusted ORs for ‘current osteoporosis’ were 1.16 (95% CI 1.08–1.25) in the Weight L&M group and 1.77 (95% CI 1.54–2.02) in the Weight gain group. Conclusions: Compared to the Never tried group, being in either the Weight L&M or Weight gain groups showed a significant impact on the possibility of osteoporosis.

Non-alcoholic fatty liver disease (NAFLD) is associated with an increased incidence of osteoporosis and bone fractures

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) and osteoporosis are common diseases with a rising incidence worldwide. Both diseases occur in similar patient populations, however, data on their mutual influence are conflicting. Here, we aimed to evaluate the impact of NAFLD on the incidence of osteoporosis and fractures by using the Disease Analyzer database featuring data on diagnoses, prescriptions, and demographic aspects of 7.49 million cases followed in general practices in Germany.

METHODS

A total of 50,689 patients with NAFLD diagnosed between 2000 and 2015 were matched by age, sex, index year, and 3 comorbidities (obesity, diabetes mellitus, and vitamin D/calcium deficiency) to a cohort of equal size without NAFLD. Incidence of osteoporosis and bone fractures were compared between both groups within 10 years from the index date.

RESULTS

Within the observation period, the incidence of osteoporosis was significantly higher in the NAFLD group (6.4%) compared to patients without NAFLD (5.1%; log-rank, p < 0.001). Similar results were observed for bone fractures (12.6 vs. 10.3 %; log-rank p < 0.001). The difference was more pronounced in women compared to men and observed in all age groups >50 years of age.

CONCLUSION

Our data show that NAFLD is significantly associated with osteoporosis as well as bone fractures in a large cohort of patients followed in German general practices. This finding suggests that NAFLD patients might benefit from improved monitoring for the occurrence of bone demineralization and osteoporosis, which in turn could trigger preventive therapeutic measures.

Detecting causal relationship between metabolic traits and osteoporosis using multivariable Mendelian randomization

By adopting the extension approaches of Mendelian randomization, we successfully detected and prioritized the potential causal risk factors for BMD traits, which might provide us novel insights for treatment and intervention into bone-related complex traits and diseases.

INTRODUCTION

Osteoporosis (OP) is a common metabolic skeletal disease characterized by reduced bone mineral density (BMD). The identified SNPs for BMD can only explain approximately 10% of the variability, and very few causal factors have been identified so far.

METHODS

The Mendelian randomization (MR) approach enables us to assess the potential causal effect of a risk factor on the outcome by using genetic IVs. By using extension methods of MR-multivariable MR (mvMR) and MR based on Bayesian model averaging (MR-BMA)-we intend to estimate the causal relationship between fifteen metabolic risk factors for BMD and try to prioritize the most potential causal risk factors for BMD.

RESULTS

Our analysis identified three risk factors T2D, FG, and HCadjBMI for FN BMD; four risk factors FI, T2D, HCadjBMI, and WCadjBMI for FA BMD; and three risk factors FI, T2D, and HDL cholesterol for LS BMD, and all risk factors were causally associated with heel BMD except for triglycerides and WCadjBMI. Consistent with the mvMR results, MR-BMA confirmed those risk factors as top risk factors for each BMD trait individually.

CONCLUSIONS

By combining MR approaches, we identified the potential causal risk factors for FN, FA, LS, and heel BMD individually and we also prioritized and ranked the potential causal risk factors for BMD, which might provide us novel insights for treatment and intervention into bone-related complex traits and diseases.

Relationships between anthropometric adiposity indexes and bone mineral density in a cross-sectional Chinese study

BACKGROUND CONTEXT

Previous studies have reported conflicting results for the relationships between anthropometric adiposity indexes and bone mineral density, based on dual-energy X-ray absorptiometry (DXA). However, few studies were published based on quantitative computed tomography (QCT), especially for Chinese population.

PURPOSE

To evaluate the associations of spine bone mineral density (BMD) with body mass index (BMI), waist circumstance (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR) and a body shape index (ABSI) using QCT.

STUDY DESIGN/SETTING

A Cross-sectional study.

PATIENT SAMPLE

Around 3,457 participants in multiple communities across 7 administrative regions of China.

OUTCOME MEASURES

Spine BMD was measured using QCT, and the classification of osteoporosis was defined as follows: 1) osteoporosis if BMD <80mg/cm³, 2) osteopenia if BMD 80-119 mg/cm³, and 3) normal bone mass if BMD≥120 mg/cm³.

METHODS

This study was conducted using convenient sampling between 2013 and 2017. Multivariable linear regression model and logistic regression models were used for the associations of continuous and categorical BMD, respectively.

RESULTS

Around 3,405 participants were included in the final analyses, including 1,272 males and 2,133 females, with spine BMD of 111.00±35.47 mg/cm³ and 99.38±40.60 mg/cm³, respectively. Spine BMD decreased significantly with the increase of ABSI in females (adjusted β, -5.74; 95% confidence interval [CI], -8.50 to -2.98), and this trend also was kept in females aged at less than 60 years (adjusted β, -14.54; 95% CI, -20.40 to -8.68), and females with age ≥60 years (adjusted β, -7.59; 95% CI, -10.91 to -4.28). However, this inverse association was observed only in males with age ≥ 60 years (adjusted β, -5.19; 95% CI, -10.08 to -0.29). Except ABSI, negative associations of Spine BMD with WC (adjusted β, -0.46; 95% CI, -0.77 to -0.15), WHR (adjusted β, -6.25; 95% CI, -10.63 to -1.86), WHtR (adjusted β, -6.80; 95% CI, -11.63 to -1.97) were shown in females aged at <60 years, and positive association with BMI in males with age ≥60 years (adjusted β, 0.92; 95% CI, 0.29-1.55).

CONCLUSIONS

ABSI had more remarkable association with spine BMD, compared with the other four indexes.

Association between Metabolic Syndrome and Osteoporosis: A Systematic Review and Meta-Analysis

BACKGROUND

Previous studies have reached mixed conclusions regarding the association between metabolic syndrome (MS) and osteoporosis. We aimed to perform a meta-analysis based on published studies that explored the association between osteoporosis and MS.

METHODS

To identify related literature, a systematic search of PubMed, Cochrane Library, and EMBASE databases from inception to June 2020 was performed. Original studies that reported the risk estimates of osteoporosis morbidity for two or three categories of bone mineral density (BMD) in patients with MS were selected. Two independent investigators screened and selected the articles. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using random-effects models.

RESULTS

Of 2632 identified studies, nine cross-sectional studies with 14 datasets were eligible for our meta-analysis. In seven studies (10 datasets), the summarized ORs of osteoporosis for MS were 0.72 (95% CI: 0.52-0.99). Subgroup analyses by gender showed that significant inverse associations were observed only in men (OR = 0.72, 95% CI: 0.55-0.96) but not in women (OR = 0.70, 95% CI: 0.41-1.22). The definition of MS, the source of the study population, and the adjustment of covariates affected the estimates. In two studies (4 datasets), there was no evidence for an association between MS and decreased BMD.

CONCLUSIONS

Our findings demonstrated that MS was significantly associated with a lower osteoporosis risk. There might be gender differences in the association between MS and osteoporosis. In addition, the association was likely to relate to the definition of MS, the source of the study population, and the adjustment of covariates.

Effect of Qing'e Decoction on Leptin/Leptin Receptor and Bone Metabolism in Naturally Aging Rats

Senile osteoporosis (SOP) is a common disease that has decreased bone strength as its main symptom. There is currently no medication that can treat SOP, and traditional Chinese medicine has advantages in slowing down bone aging. The present study aimed to observe the effects of Qing'e decoction on leptin, leptin receptor, sex hormone, and biochemical markers of bone metabolism in naturally aging rats and to explore its mechanism in regulating bone metabolism. The results revealed that, with the increase in age, the bone mineral density (BMD), bone strength, bone trabecula sparse, serum levels of leptin receptor (LEP-R), estradiol (E2), testosterone (T), core binding-factor α-1 (Cbfα-1), collagen-I (COL-I) and osteocalcin (OC), and the mRNA levels of leptin (LEP) and LEP-R in bone tissue decreased, while serum LEP levels increased in the female and male NS groups. The serum levels of LEP, LEP-R, E2, T, osteoprotegerin, Cbfα-1, COL-I, OC and bone alkaline phosphatase, and the mRNA levels of LEP and LEP-R in bone tissue in the female and male QED groups were higher than those in the same age and sex NS group, while the BMD, bone trabecular area percentage, maximum load, and maximum stress in the female and male QED groups were significantly higher than those in the same age and sex NS group. In conclusion, with the increase in age, the bone quality of naturally aging rats decreased gradually. Qing'e decoction can regulate the bone metabolism and increase the bone quality and delay bone aging, which may be achieved by increasing sex hormone, LEP, and LEP-R levels.

Bone Mineral Density of Femur and Lumbar and the Relation between Fat Mass and Lean Mass of Adolescents: Based on Korea National Health and Nutrition Examination Survey (KNHNES) from 2008 to 2011

It is most important to reach the maximum bone density in the childhood period to prevent developing osteoporosis; it is widely known that increased body weight has a positive correlation with bone density and that even though both the fat mass and lean mass have a significant impact on bone density, the latter mass has more importance for adults. Therefore, the study analyzed to identify the relationship between bone density and both fat mass and lean mass of Korean adolescents. Subjects were chosen among 21,303 people from the Korea National Health and Nutrition Examination Survey (KNHNES) between 2008 and 2011 that took a bone density checkup; as a result, 1454 teenagers aged between 12 and 18 were selected. Data analysis was performed in SAS ver. 9.4 (SAS Institute Inc., Cary, NC, USA) following the KNHNES and the weighted complex sample analysis was conducted; body fat mass and lean mass were divided into quintile groups, and to figure out the differences in bone density that were analyzed in six models adjusted by body weight (kg) and walking (yes/no), muscle strengthening exercises (yes/no), nutrition (intake of ca (g), and serum vitamin D (ng/mL)). Then, the generalized linear model (GLM) and trend test were conducted for each gender with a significance level of 0.05. The bone density differences of fat mass and lean mass were analyzed. The result of Model 6 considering all correction variables is as follows; in the case of male adolescents, the total femur and lumbar spine showed a significant difference (F = 13.120, p < 0.001; F = 12.900, p < 0.001) for fat mass, and the trend test showed that the figures significantly decreased (β = −0.030, p < 0.001; −0.035, p < 0.001). Meanwhile, for lean mass, the total femur and lumbar spine had a significant difference (F = 16.740, p < 0.001; F = 20.590, p < 0.001) too, but the trend test showed a significant increase (β = 0.054, p < 0.001; 0.057, p < 0.001). In the case of female adolescents, the lumbar spine (F = 3.600, p < 0.05) for lean mass showed a significant difference, and it also significantly rose in the trend test too (β = 0.020, p < 0.01). To sum up the results, for male adolescents, the bone density differences for fat mass (FM) and lean mass (LM) all had significant differences, but for female adolescents, only the lumbar spine for LM showed such a result. Meanwhile, both genders showed that LM had a more positive impact on bone density than FM.

Soluble Biomarkers of Osteoporosis and Osteoarthritis, from Pathway Mapping to Clinical Trials: An Update

Serum biomarkers of osteoarticular diseases have been in the limelight of current clinical research trends. Laboratory validation of defined and candidate biomarkers for both osteoarthritis and osteoporosis is of key importance for future decisional algorithms in the diagnosis, monitoring, and prognosis of these diseases. The current guidelines recommend the use of collagen degradation remnants, eg, CTX-I and CTX-II, in the complementary diagnosis of both osteoporosis and osteoarthritis. Besides the collagen degradation markers, enzymes that regulate bone and articular metabolism are useful in the clinical evaluation of osteoarticular pathologies. Along these, several other recommended and new nominee molecules have been recently studied. Wnts and Wnt-related molecules have a cardinal role in the bone-joint homeostasis, making them a promising target not only for pharmaceutical modulation, but also to be considered as soluble biomarkers. Sclerostin and dickkopf, two inhibitor molecules of the Wnt/β-catenin signaling, might have a dual role in the assessment of the clinical manifestations of the osteoarticular unit. In osteoarthritis, besides fragments of collagen type II many pathway-related molecules have been studied and proposed for biomarker validation. The most serious limitation is that a significant proportion of studies lack statistical power due to the reduced number of cases enrolled. Serum biomarkers of bone and joint turnover markers represent an encouraging possibility for the diagnosis and prognosis of osteoarticular diseases, although further studies and laboratory validations should be carried out as to solely rely on them.

Effect of Weight Change Following Intentional Weight Loss on Bone Health in Older Adults with Obesity

OBJECTIVE

This study aimed to examine change in bone mineral density (BMD) and trabecular bone score among older adult weight regainers (WR) and weight maintainers (WM).

METHODS

Observational data come from 77 older adults (mean age: 67 [SD 5] years; 69% women; 70% white) with obesity (mean BMI: 33.6 [SD  3.7] kg/m² ) who lost weight during an 18-month weight loss intervention. Total body mass and body composition, along with regional (total hip, femoral neck, lumbar spine) BMD and trabecular bone score, were measured at baseline, 18 months, and 30 months. WR (n = 36) and WM (n = 41) categories were defined as a ≥ 5% or < 5% weight gain from 18 to 30 months, respectively.

RESULTS

Among skeletal indices, only total hip BMD was significantly reduced during the 18-month intervention period in both WRs (-3.9%; 95% CI: -5.8% to -2.0%) and WMs (-2.4%; 95% CI: -4.3% to -0.5%; P = 0.07). After adjustment for relevant baseline covariates and weight change from 0 to 18 months, 30-month change in total hip BMD was -2.6% (95% CI: -4.3% to -0.9%) and -3.9% (95% CI: -5.7% to -2.1%) among WRs and WMs, respectively (P = 0.07).

CONCLUSIONS

Loss of hip BMD persists in the year after a weight loss intervention among older adults with obesity, regardless of weight regain status.

Thy-1 Deficiency Augments Bone Loss in Obesity by Affecting Bone Formation and Resorption

Healthy bone remodeling results from a balanced bone formation and bone resorption realized by bone-forming osteoblasts and bone-resorbing osteoclasts, respectively. Recently, Thy-1 (CD90) was identified as positive regulator of osteoblast differentiation and activation, thus, promoting bone formation while concurrently inhibiting adipogenesis and obesity in mice. Additionally, Thy-1 did not affect bone resorption. An obesity-related co-morbidity that is increasing in prevalence is a disturbed bone formation resulting in an increased fracture risk. The underlying mechanisms of obesity-induced bone alterations are not yet fully elucidated and therefore therapy options for efficient bone-anabolic treatments are limited. Therefore, we investigated the impact of Thy-1 on bone metabolism under obese conditions. Indeed, high fat diet (HFD) induced obese mice lacking Thy-1 (Thy-1^−/−) showed increased body fat mass compared to wildtype (WT) mice while bone mass (−38%) and formation (−57%) were decreased as shown by micro-computed tomography (μCT) measurement, histological analysis, and fourier-transform infrared spectroscopy (FTIR). Interestingly, under obese conditions, lack of Thy-1 affected both osteoblast and osteoclast function. Number (−30%) and activity of osteoblasts were decreased in obese Thy-1^−/− mice while osteoclast number (+39%) and activity were increased. Facilitated bone marrow fat accumulation (+56%) in obese Thy-1^−/− mice compared to obese WT mice was associated with upregulated tumor necrosis factor α (Tnfα, +46%) and colony stimulating factor 1 receptor (Csf1r) expression, strong promoters of osteoclast differentiation. Moreover, lack of Thy-1 was accompanied by a reduction of osteoprotegerin (Tnfrsf11b) expression (−36%), an inhibitor of osteoclast differentiation. Altered Tnfα, Csf1r, and Tnfrsf11b expression might be responsible for elevated osteoclast activity in obese Thy-1-deficient mice. In summary, our findings show that lack of Thy-1 promotes obesity under HFD conditions while concurrently decreasing bone mass and formation. Mechanistic studies revealed that under obese conditions lack of Thy-1 impairs both bone formation and bone resorption.

Association between Anthropometric Indices, Body Composition and Bone Parameters in Thai Female Adolescents

OBJECTIVE

To investigate correlations between anthropometrics and body composition with bone parameters of the whole-body and lumbar spine in non-obese and obese Thai female adolescents.

METHODS

This study was performed in 135 female adolescents aged 15 to 18 y enrolled in secondary schools in southern Thailand. Subjects were grouped into non-obesity (underweight and normal-to-overweight) (BMI < 25) and obesity (BMI ≥ 25) groups. Anthropometric indices for obesity [body weight (BW), waist circumference (WC), and body mass index (BMI)] were recorded. Bone parameters (BMC, BMD, and Z-scores) of the whole-body and lumbar spine (L1-L4) and body composition (LBM, BFM, %fat, %lean, and %bone) were assessed by dual-energy X-ray absorptiometry (DXA). Correlations between anthropometrics, body composition, and bone parameters were evaluated and compared between subject groups.

RESULTS

The obesity group had significantly higher means of whole-body BMD, BMC and Z-score than non-obese group (p < 0.05). BMI and BW were positively associated with BFM and %fat (p < 0.05) for non-obese subjects. Obese subjects had greater lumbar spine BMC compared to non-obese subjects. BFM was correlated with whole-body BMC in obese group. BW was a positive determinant of BMC at both sites in all subject groups, particularly for obese subjects; BW had positive associations with all bone parameters at the lumbar spine.

CONCLUSIONS

BW can be used as a determinant of all bone parameters at lumbar spine, and BFM had a positive effect on whole-body BMC in Thai obese female adolescent subjects.

Lycium barbarum polysaccharide arbitrates palmitate-induced apoptosis in MC3T3‑E1 cells through decreasing the activation of ERS‑mediated apoptosis pathway

Palmitate (PA) has been identified to induce cell apoptosis in osteoblasts. The c-Jun NH2-teminal kinase (JNK) signaling pathway and endoplasmic reticulum stress (ERS) were found to be important contributors. Therefore, natural or synthetic agents may antagonize PA-induced apoptosis in osteoblasts, and demonstrate the potential application to reverse osteoporosis. The present study demonstrated that the Lycium barbarum polysaccharide (LBP) is as a major active ingredient of Lycium barbarum and that it can reduce the fatty acid toxicity of PA. Furthermore, this study attempted to elucidate the underlying molecular mechanisms of LBP. Firstly, it was demonstrated via a Cell Counting Kit-8 assay, that LBP could significantly increase the viability of MC3T3-E1 cells in a dose-dependent manner. Flow cytometric analysis indicated that LBP inhibits PA-induced apoptosis in osteoblastic cells. Reverse transcription-quantitative polymerase chain reaction and western blotting results showed that the expression levels of glucose-regulated protein 78, C/EBP homologous protein and cysteinyl asparate specific proteinase-3/-9/-12, were increased in MC3T3-E1 cells following PA treatment. The treatment of the cells with PA resulted in an activation of the ERS and the JNK signaling pathway. These pathways were effectively suppressed by co-incubation with LBP. Taken together, PA may cause ERS, in cell apoptosis, and it may further activate the JNK signaling pathway. LBP reversed PA-induced apoptosis in MC3T3-E1 cells through inhibition of the activation of the ERS-mediated JNK signaling pathway.

Mini-Review: The Contribution of Intermediate Phenotypes to GxE Effects on Disorders of Body Composition in the New OMICS Era

Studies of gene-environment (GxE) interactions describe how genetic and environmental factors influence the risk of developing disease. Intermediate (molecular or clinical) phenotypes (IPs) are traits or metabolic biomarkers that mediate the effects of gene-environment influences on risk behaviors. Functional systems genomics discovery offers mechanistic insights into how DNA variations affect IPs in order to detect genetic causality for a given disease. Disorders of body composition include obesity (OB), Type 2 diabetes (T2D), and osteoporosis (OSTP). These pathologies are examples of how a GxE interaction contributes to their development. IPs as surrogates for inherited genotypes play a key role in models of genetic and environmental interactions in health outcomes. Such predictive models may unravel relevant genomic and molecular pathways for preventive and therapeutic interventions for OB, T2D, and OSTP. Annotation strategies for genomes, in contrast to phenomes, are well advanced. They generally do not measure specific aspects of the environment. Therefore, the concepts of deep phenotyping and the exposome generate new avenues to exploit with high-resolution technologies for analyzing this sophisticated phenome. With the successful characterization of phenomes, exposomes, and genomes, environmental and genetic determinants of chronic diseases can be united with multi-OMICS studies that better examine GxE interactions.

Evaluation of circulating sRAGE in osteoporosis according to BMI, adipokines and fracture risk: a pilot observational study

Background

Osteoporosis is a systemic metabolic disease based on age-dependent imbalance between the rates of bone formation and bone resorption. Recent studies on the pathogenesis of this disease identified that bone remodelling impairment, at the base of osteoporotic bone fragility, could be related to protein glycation, in association to oxidative stress. The glycation reactions lead to the generation of glycation end products (AGEs) which, in turn, accumulates into bone, where they binds to the receptor for AGE (RAGE). The aim of this study is to investigate the potential role of circulating sRAGE in osteoporosis, in particular evaluating the correlation of sRAGE with the fracture risk, in association with bone mineral density, the fracture risk marker FGF23, and lipid metabolism.

Results

Circulating level of soluble RAGE correlate with osteopenia and osteoporosis level. Serum sRAGE resulted clearly associated on the one hand to bone fragility and, on the other hand, with BMI and leptin. sRAGE is particularly informative because serum sRAGE is able to provide, as a single marker, information about both the aspects of osteoporotic disease, represented by bone fragility and lipid metabolism.

Conclusions

The measure serum level of sRAGE could have a potential diagnostic role in the monitoring of osteoporosis progression, in particular in the evaluation of fracture risk, starting from the prevention and screening stage, to the osteopenic level to osteoporosis.

Inhibiting DNA methylation switches adipogenesis to osteoblastogenesis by activating Wnt10a

Both adipocytes and osteoblasts share the mesodermal lineage that derives from mesenchymal stem cells. Most studies investigating the mechanisms underlying the regulation of adipogenic or osteoblastogenic development focus on transcriptional pathways; little is known about the epigenetic mechanisms in this process. We thus determined the role of 5-aza-2′-deoxycytidine (5-Aza-dC), an inhibitor of DNA methylation, in the lineage determination between adipogenesis and osteoblastogenesis. Inhibiting DNA methylation in 3T3-L1 preadipocytes by 5-Aza-dC significantly inhibited adipogenesis whereas promoted osteoblastogenesis. This dual effect of 5-Aza-dC was associated with up-regulation of Wnt10a, a key factor determining the fate of the mesenchymal lineage towards osteoblasts. Consistently, IWP-2, an inhibitor of Wnt proteins, was found to prevent the anti-adipogenic effect of 5-Aza-dC in 3T3-L1 preadipocytes and block the osteoblastogenic effect of 5-Aza-dC in ST2 mesenchymal stem cell line. Finally, the Wnt10a 5′-region is enriched with CpG sites, whose methylation levels were markedly reduced by 5-Aza-dC. Thus we conclude that inhibiting DNA methylation by 5-Aza-dC mutual-exclusively regulates the lineage determination of adipogenesis and osteoblastogenesis by demethylating Wnt10a gene and upregulating its expression. Our study defines DNA methylation as a novel mechanism underlying adipocyte and bone cell development.

Regulation of Obesity and Metabolic Complications by Gamma and Delta Tocotrienols

Tocotrienols (T3s) are a subclass of unsaturated vitamin E that have been extensively studied for their anti-proliferative, anti-oxidative and anti-inflammatory properties in numerous cancer studies. Recently, T3s have received increasing attention due to their previously unrecognized property to attenuate obesity and its associated metabolic complications. In this review, we comprehensively evaluated the recent published scientific literature about the influence of T3s on obesity, with a particular emphasis on the signaling pathways involved. T3s have been demonstrated in animal models or human subjects to reduce fat mass, body weight, plasma concentrations of free fatty acid, triglycerides and cholesterol, as well as to improve glucose and insulin tolerance. Their mechanisms of action in adipose tissue mainly include (1) modulation of fat cell adipogenesis and differentiation; (2) modulation of energy sensing; (3) induction of apoptosis in preadipocytes and (4) modulation of inflammation. Studies have also been conducted to investigate the effects of T3s on other targets, e.g., the immune system, liver, muscle, pancreas and bone. Since δT3 and γT3 are regarded as the most active isomers among T3s, their clinical relevance to reduce obesity should be investigated in human trials.

Association of Trabecular Bone Score with Inflammation and Adiposity in Patients with Psoriasis: Effect of Adalimumab Therapy

Studies on trabecular bone score (TBS) in psoriasis are lacking. We aim to assess the association between TBS and inflammation, metabolic syndrome features, and serum adipokines in 29 nondiabetic patients with psoriasis without arthritis, before and after 6-month adalimumab therapy. For that purpose, adjusted partial correlations and stepwise multivariable linear regression analysis were performed. No correlation was found between TBS and disease severity. TBS was negatively associated with weight, BMI, waist perimeter, fat percentage, and systolic and diastolic blood pressure before and after adalimumab. After 6 months of therapy, a negative correlation between TBS and insulin resistance (p = 0.02) and leptin (p = 0.01) and a positive correlation with adiponectin were found (p = 0.01). The best set of predictors for TBS values at baseline were female sex (p = 0.015), age (p = 0.05), and BMI (p = 0.001). The best set of predictors for TBS following 6 months of biologic therapy were age (p = 0.001), BMI (p < 0.0001), and serum adiponectin levels (p = 0.027). In conclusion, in nondiabetic patients with moderate-to-severe psoriasis, TBS correlates with metabolic syndrome features and inflammation. This association is still present after 6 months of adalimumab therapy. Moreover, serum adiponectin levels seem to be an independent variable related to TBS values, after adalimumab therapy.

Influence of obesity on vertebral fracture prevalence and vitamin D status in postmenopausal women

Background

It is well established that weight is an important determinant of bone health. Whereas obesity is associated with increased mortality and morbidity from diabetes and cardiovascular diseases, high body weight is widely believed to be associated to hypovitaminosis D and protective against the development of osteoporosis and fracture risk. The objective of the study was to evaluate the effect of BMI on vitamin D status and on densitometric vertebral fractures (VFs) in a large series of asymptomatic women aged over 50 who had a VFA examination during their bone mineral density (BMD) testing.

Methods

We enrolled 429 postmenopausal women (mean age, weight and BMI of 59.5 ± 8.3 (50 to 83) years, 75.8 ± 13.3 (35 to 165) kgs and 29.9 ± 5.2 (14.6 to 50.8) kg/m², respectively. Lateral VFA images and scans of the lumbar spine and proximal femur were obtained using a Lunar Prodigy densitometer. VFs were defined using the Genant semiquantitative (SQ) approach. Clinical risk factors of osteoporosis were collected and 25-hydroxivitamin D was measured using electrochimiluminescence (Roche).

Results

Prevalence of osteoporosis and hypovitaminosis D (<20 ng/ml) was 21.0 % and 78.1 % respectively. VFs grade 2/3were identified in 76 (17.7 %). Comparison between women according to their BMI showed that obese women had a higher BMD and less proportion of women with osteoporosis and VFs grade 2/3 than lean and overweight women. The prevalence of VFs globally increased with age and as BMI and BMD declined. Stepwise regression analysis showed that the presence of osteoporosis was independently related to BMI and history of fractures while the presence of grade 2/3 VFs was independently related to age, hypovitaminosis D and years of menopause.

Conclusion

Obese women had a higher BMD and lower prevalence of VFs. VFs were significantly related to age, hypovitaminosis D and years since menopause. However, among obese women, prevalence of VFs was increased in osteoporotic women.

Adiponectin regulates bone marrow mesenchymal stem cell niche through a unique signal transduction pathway: an approach for treating bone disease in diabetes

Adiponectin (APN) is an adipocyte-secreted adipokine that exerts well-characterized antidiabetic properties. Patients with type 2 diabetes (T2D) are characterized by reduced APN levels in circulation and impaired stem cell and progenitor cell mobilization from the bone marrow for tissue repair and remodeling. In this study, we found that APN regulates the mobilization and recruitment of bone marrow-derived mesenchymal stem cells (BMSCs) to participate in tissue repair and regeneration. APN facilitated BMSCs migrating from the bone marrow into the circulation to regenerate bone by regulating stromal cell-derived factor (SDF)-1 in a mouse bone defect model. More importantly, we found that systemic APN infusion ameliorated diabetic mobilopathy of BMSCs, lowered glucose concentration, and promoted bone regeneration in diet-induced obesity mice. In vitro studies allowed us to identify Smad1/5/8 as a novel signaling mediator of APN receptor (AdipoR)-1 in BMSCs and osteoblasts. APN stimulation of MC3T3-E1 osteoblastic cells led to Smad1/5/8 phosphorylation and nuclear localization and increased SDF-1 mRNA expression. Although APN-mediated phosphorylation of Smad1/5/8 occurred independently from adaptor protein, phosphotyrosine interaction, pleckstrin homology domain, and leucine zipper containing 1, it correlated with the disassembly of protein kinase casein kinase 2 and AdipoR1 in immunoprecipitation experiments. Taken together, this study identified APN as a regulator of BMSCs migration in response to bone injury. Therefore, our findings suggest APN signaling could be a potential therapeutic target to improve bone regeneration and homeostasis, especially in obese and T2D patients.

Serum Chemerin Levels in relation to Osteoporosis and Bone Mineral Density: A Case-Control Study

BACKGROUND

To evaluate serum chemerin levels in patients with osteoporosis and healthy controls and to investigate the relationship between serum chemerin levels and bone mineral density (BMD).

METHODS

An age- and gender-matched case-control study was conducted. Pearson's correlation test was performed to investigate the relationship between serum chemerin levels and BMD.

RESULTS

There were 93 patients included in the osteoporosis group and 93 matched controls. Serum chemerin level was significantly higher in patients with osteoporosis (87.27 ± 5.80 ng/mL) than patients in control (71.13 ± 5.12 ng/mL) (P < 0.01). There was a negative correlation between femoral bone mineral density and chemerin in both groups (R = -0.395, P < 0.01 in osteoporosis group; R = -0.680, P < 0.01 in control) and also a negative correlation between lumbar bone mineral density with chemerin in both groups (R = -0.306, P < 0.01 in osteoporosis group; R = -0.362, P < 0.01 in control).

CONCLUSIONS

Patients with osteoporosis presented a higher level of serum chemerin, which witnessed an inverse correlation with BMD. Further studies are needed to explore the role of chemerin in the pathophysiology of osteoporosis.