Increasing adiposity is associated with higher adipokine levels and lower bone mineral density in obese older adults

[Bone mineral density in women with rheumatoid arthritis: A link between immune and biochemical markers]

AIM

To study the association of bone mineral density (BMD) with serum biochemical and immunological markers in postmenopausal women with rheumatoid arthritis (RA).

MATERIALS AND METHODS

The study included 173 women with RA (age 61.0 [56.0; 66.0] years). A survey, dual-energy X-ray absorptiometry to measure the BMD of the lumbar spine (LI-LIV), femoral neck (FN) and total hip (TH), routine blood chemistry, measurement of C-reactive protein (CRP), rheumatoid factor, cyclic citrullinated peptide antibodies (CCPA), parathyroid hormone (PTH), vitamin D3, myostatin, follistatin, interleukin-6 (IL-6), IL-6 receptors, insulin-like growth factor 1, adiponectin, leptin, fibroblast growth factor 23, and tumor necrosis factor SF12 were performed.

RESULTS

PTH (β=-0.22, -0.35 and -0.30 for LI-LIV, FN and TH, respectively), CRP (β=-0.18, 0.23 and -0.22 for LI-LIV, FN and TH, respectively) and leptin (β=0.35, 0.32 and 0.42 for LI-LIV, FN and TH, respectively) were shown a significant association with BMD in all sites of measurement. It was independent of age, body mass index and postmenopause duration. Associations were also found between adiponectin and BMD of LI-LIV and TH (β=-0.36 and -0.28, respectively), CCPA and BMD of FN and TH (β=-0.21, -0.24, respectively) and IL-6 and BMD of FN (β=0.37).

CONCLUSION

The study of biochemical and immunological markers in women with RA demonstrated that CRP, CCPA, PTH, IL-6, adiponectin, and leptin influenced BMD.

Lipolysis products from triglyceride-rich lipoproteins induce stress protein ATF3 in osteoblasts

High fat diets overwhelm the physiological mechanisms for absorption, storage, and utilization of triglycerides (TG); consequently TG, TG-rich lipoproteins (TGRL), and TGRL remnants accumulate, circulate systemically, producing dyslipidemia. This associates with, or is causative for increased atherosclerotic cardiovascular risk, ischemic stroke, fatty liver disease, and pancreatitis. TGRL hydrolysis by endothelial surface-bound lipoprotein lipase (LPL) generates metabolites like free fatty acids which have proinflammatory properties. While osteoblasts utilize fatty acids as an energy source, dyslipidemia is associated with negative effects on the skeleton. In this study we investigated the effects of TGRL lipolysis products (TGRL-LP) on expression of a stress responsive transcription factor, termed activating transcription factor 3 (ATF3), reactive oxygen species (ROS), ATF3 target genes, and angiopoietin-like 4 (Angptl4) in osteoblasts. As ATF3 negatively associates with osteoblast differentiation, we also investigated the skeletal effects of global ATF3 deletion in mice. TGRL-LP increased expression of Atf3, proinflammatory proteins Ptgs2 and IL-6, and induced ROS in MC3T3-E1 osteoblastic cells. Angptl4 is an endogenous inhibitor of LPL which was transcriptionally induced by TGRL-LP, while recombinant Angptl4 prevented TG-driven Atf3 induction. Atf3 global knockout male mice demonstrated increased trabecular and cortical microarchitectural parameters. In summary, we find that TGRL-LP induce osteoblastic cell stress as evidenced by expression of ATF3, which may contribute to the negative impact of dyslipidemia in the skeleton. Further, concomitant induction of Angptl4 in osteoblasts might play a protective role by reducing local lipolysis.

Risk of Obesity and Unhealthy Central Adiposity in Adolescents Born Preterm With Very Low Birthweight Compared to Term-Born Peers

Background: Early-life factors such as preterm birth or very low birthweight (VLBW) are associated with increased cardiovascular disease risk. However, it remains unknown whether this is due to an increased risk of obesity (unhealthy central adiposity) because studies have predominantly defined obesity based on BMI, an imprecise adiposity measure. Objective: Investigate if adolescents born preterm with VLBW have a higher risk of unhealthy central adiposity compared to term-born peers. Study Design: Cross-sectional analysis of data from a prospective cohort study of 177 individuals born preterm with VLBW (<1500 g) and 51 term-born peers (birthweight ≥2500 g). Individuals with congenital anomalies, genetic syndromes, or major health conditions were excluded. Height, weight, waist circumference, skin fold thickness, and dual energy X-ray absorptiometry body composition were measured at age 14 years. We calculated BMI percentiles and defined overweight/obesity as BMI ≥85th percentile for age and sex. We estimated the preterm-term differences in overweight/obesity prevalence and adiposity distribution with multivariable generalized linear models. Results: There was no difference in small for gestational age status or overweight/obesity prevalence. Compared to term, youth born preterm with VLBW had lower BMI z-score [β -0.38, 95% confidence limits (CL) -0.75 to -0.02] but no differences in adiposity apart from subscapular-to-triceps ratio (STR; β 0.18, 95% CL 0.08 to 0.28). Conclusions: Adolescents born preterm with VLBW had smaller body size than their term-born peers and had no differences in central adiposity except greater STR.

Obesity and Skeletal Fragility

Skeletal fracture has recently emerged as a complication of obesity. Given the normal or better than normal bone mineral density (BMD), the skeletal fragility of these patients appears to be a problem of bone quality rather than quantity. Type 2 diabetes mellitus (T2DM), the incidence of which increases with increasing body mass index, is also associated with an increased risk for fractures despite a normal or high BMD. With the additional bone pathology from diabetes itself, patients with both obesity and T2DM could have a worse skeletal profile. Clinically, however, there are no available methods for identifying those who are at higher risk for fractures or preventing fractures in this subgroup of patients. Weight loss, which is the cornerstone in the management of obesity (with or without T2DM), is also associated with an increased risk of bone loss. This review of the literature will focus on the skeletal manifestations associated with obesity, its interrelationship with the bone defects associated with T2DM, and the available approach to the bone health of patients suffering from obesity.

Comparison of changes in adipokine and inflammatory cytokine levels in patients with newly diagnosed type 2 diabetes treated with exenatide, insulin, or pioglitazone: A post-hoc study of the CONFIDENCE trial

Background

Adipokines and inflammatory cytokines (ADICs) play important roles in type 2 diabetes mellitus (T2DM). This study aimed to compare the changes of ADIC levels (ΔADICs) in patients with newly diagnosed T2DM treated with different antihyperglycemic agents, and further investigate the impact of these changes on metabolic indices, β-cell function and insulin resistance (IR).

Methods

Four hundred and sixteen patients with newly diagnosed T2DM from 25 centers in China randomly received 48-week intervention with exenatide, insulin or pioglitazone. Anthropometric and laboratory data, indices of β-cell function and IR, and levels of AIDCs, including interleukin-1 beta (IL-1β), interferon-gamma (IFN-γ), leptin, and fibroblast growth factor 21 (FGF21) were detected at baseline and the end of the study.

Results

In total, 281 participants (68 % male, age: 50.3 ± 9.4 years) completed the study. After 48- week treatment, IL-1β and IFN-γ were significantly decreased with exenatide treatment (P < 0.001 and P = 0.001, respectively), but increased with insulin (P = 0.009 and P = 0.026, respectively). However, pioglitazone treatment had no impact on ADICs. No significant change in leptin or FGF21 was detected with any of the treatments. After adjustment for baseline values and changes of body weight, waist and HbA1c, the between-group differences were found in ΔIL-1β (exenatide vs. insulin: P = 0.048; and exenatide vs. pioglitazone: P = 0.003, respectively) and ΔIFN-γ (exenatide vs. insulin: P = 0.049; and exenatide vs. pioglitazone: P < 0.001, respectively). Multiple linear regression analysis indicated that Δweight was associated with ΔIL-1β (β = 0.753; 95 % CI, 0.137-1.369; P = 0.017). After adjusting for treatment effects, Δweight was also be correlated with ΔFGF21 (β = 1.097; 95%CI, 0.250-1.944; P = 0.012); furthermore, ΔHOMA-IR was correlated with Δleptin (β = 0.078; 95%CI, 0.008-0.147; P = 0.029) as well. However, ΔHOMA-IR was not significantly associated with ΔIL-1β after adjusting for treatment effects (P = 0.513).

Conclusion

Exenatide treatment led to significant changes of inflammatory cytokines levels (IL-1β and IFN-γ), but not adipokines (leptin and FGF21), in newly diagnosed T2DM patients. The exenatide-mediated improvement in weight and IR may be associated with a decrease in inflammatory cytokine levels.

Lower Adherence to a Mediterranean Diet Is Associated with High Adiposity in Community-Dwelling Older Adults: Results from the Longevity Check-Up (Lookup) 7+ Project

High adiposity impacts health and quality of life in old age, owing to its association with multimorbidity, decreased physical performance, and frailty. Whether a high adherence to a Mediterranean diet (Medi-Diet) is associated with reduced body adiposity in older adults is unclear. The present study was conducted to assess the prevalence of high adiposity in a large sample of community-dwelling older adults. We also explored the relationship between whole-body adiposity estimated through relative fat mass (RFM) and Medi-Diet adherence. Data were obtained from the Longevity Check-up 7+ (Lookup7+) project database. RFM was estimated from anthropometric and personal parameters using a validated equation. RFM was categorized as high if ≥40% in women and ≥30% in men. Information on diet was collected using a food frequency questionnaire, while Medi-Diet adherence was assessed through a modified version of the Medi-Lite scoring system. Analyses were conducted in 2092 participants (mean age 73.1 ± 5.9 years; 53.4% women). Mean RFM was 39.6 ± 5.14% in women and 29.0 ± 3.6% in men. High adiposity was found in 971 (46.4%) participants and was more frequent in those with a low (54.2%) or moderate (46.4%) Medi-Diet adherence compared with the high-adherence group (39.7%, p < 0.001). Logistic regression indicated that older adults with high Medi-Diet adherence were less likely to have a high RFM. Other factors associated with a greater risk of having high adiposity were older age, female sex, and physical inactivity. Our findings support an association between healthy lifestyles, including a greater adherence to a Mediterranean-style diet, and lower body adiposity in older adults.

Insights into the underlying pathogenesis and therapeutic potential of endoplasmic reticulum stress in degenerative musculoskeletal diseases

Degenerative musculoskeletal diseases are structural and functional failures of the musculoskeletal system, including osteoarthritis, osteoporosis, intervertebral disc degeneration (IVDD), and sarcopenia. As the global population ages, degenerative musculoskeletal diseases are becoming more prevalent. However, the pathogenesis of degenerative musculoskeletal diseases is not fully understood. Previous studies have revealed that endoplasmic reticulum (ER) stress is a stress response that occurs when impairment of the protein folding capacity of the ER leads to the accumulation of misfolded or unfolded proteins in the ER, contributing to degenerative musculoskeletal diseases. By affecting cartilage degeneration, synovitis, meniscal lesion, subchondral bone remodeling of osteoarthritis, bone remodeling and angiogenesis of osteoporosis, nucleus pulposus degeneration, annulus fibrosus rupture, cartilaginous endplate degeneration of IVDD, and sarcopenia, ER stress is involved in the pathogenesis of degenerative musculoskeletal diseases. Preclinical studies have found that regulation of ER stress can delay the progression of multiple degenerative musculoskeletal diseases. These pilot studies provide foundations for further evaluation of the feasibility, efficacy, and safety of ER stress modulators in the treatment of musculoskeletal degenerative diseases in clinical trials. In this review, we have integrated up-to-date research findings of ER stress into the pathogenesis of degenerative musculoskeletal diseases. In a future perspective, we have also discussed possible directions of ER stress in the investigation of degenerative musculoskeletal disease, potential therapeutic strategies for degenerative musculoskeletal diseases using ER stress modulators, as well as underlying challenges and obstacles in bench-to-beside research.

Biomarkers and the post-thrombotic syndrome: A systematic review of biomarkers associated with the occurrence of the post-thrombotic syndrome after lower extremity deep venous thrombosis

INTRODUCTION

Post-thrombotic syndrome (PTS) is a frequent chronic complication of deep venous thrombosis (DVT). Biomarkers are potentially valuable clinical tools for handling PTS. The purpose of this review was to examine which biomarkers are associated with the development of PTS in adults with lower extremity DVT.

METHODS

We performed a systematic review of all English language prospective studies of biomarkers and PTS published in PubMed and EMBASE. Studies were included if diagnosing DVT by diagnostic imaging and assessing PTS by clinical scales, for example, the Villalta scale. Biomarkers of thrombophilia and pathological clot properties were not assessed. Data was reported qualitatively.

RESULTS

15 prospective studies were included. Studies varied widely in study design and methods of data analysis. Forty-six different biomarkers were examined, with seven being measured in two or more studies. The most frequently studied biomarkers were D-dimer, CRP, and IL-6. Associations between PTS and D-dimer were predominantly significant, while results on CRP and IL-6 were inconsistent. ICAM-1 was consistently associated with PTS in all studies and at all timepoints. IL-10 was significantly related to PTS development in the largest study and at all time points. Adiponectin, tPA, HRG and TAFI, MMP-1 and -8, and TIMP-1 and -2 were significantly associated with PTS in single studies.

CONCLUSION

(1) Further research on biomarkers and PTS is clearly warranted. (2) Significant differences in study designs made it difficult to draw reliable conclusions regarding individual biomarkers. We suggest the implementation of a standardized framework for the study of biomarkers and PTS, to make comparison of future studies more feasible. (3) D-dimer, ICAM-1, IL-10, MMP-1 and 8, TIMP-1, TIMP-2, and adiponectin are clinical biomarkers of particular interest to include in future studies of PTS. Large scale systemic quantitative proteomic analyses of DVT patients could help identify novel biomarkers of interest in PTS-patients.

Effect of adipokine and ghrelin levels on BMD and fracture risk: an updated systematic review and meta-analysis

Context

Circulating adipokines and ghrelin affect bone remodeling by regulating the activation and differentiation of osteoblasts and osteoclasts. Although the correlation between adipokines, ghrelin, and bone mineral density (BMD) has been studied over the decades, its correlations are still controversial. Accordingly, an updated meta-analysis with new findings is needed.

Objective

This study aimed to explore the impact of serum adipokine and ghrelin levels on BMD and osteoporotic fractures through a meta-analysis.

Data sources

Studies published till October 2020 in Medline, Embase, and the Cochrane Library were reviewed.

Study selection

We included studies that measured at least one serum adipokine level and BMD or fracture risk in healthy individuals. We excluded studies with one or more of the following: patients less than 18 years old, patients with comorbidities, who had undergone metabolic treatment, obese patients, patients with high physical activities, and a study that did not distinguish sex or menopausal status.

Data extraction

We extracted the data that include the correlation coefficient between adipokines (leptin, adiponectin, and resistin) and ghrelin and BMD, fracture risk by osteoporotic status from eligible studies.

Data synthesis

A meta-analysis of the pooled correlations between adipokines and BMD was performed, demonstrating that the correlation between leptin and BMD was prominent in postmenopausal women. In most cases, adiponectin levels were inversely correlated with BMD. A meta-analysis was conducted by pooling the mean differences in adipokine levels according to the osteoporotic status. In postmenopausal women, significantly lower leptin (SMD = -0.88) and higher adiponectin (SMD = 0.94) levels were seen in the osteoporosis group than in the control group. By predicting fracture risk, higher leptin levels were associated with lower fracture risk (HR = 0.68), whereas higher adiponectin levels were associated with an increased fracture risk in men (HR = 1.94) and incident vertebral fracture in postmenopausal women (HR = 1.18).

Conclusions

Serum adipokines levels can utilize to predict osteoporotic status and fracture risk of patients.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021224855, identifier CRD42021224855.

The causal relationship between abdominal obesity and lower bone mineral density: A two-sample mendelian randomization study

Aims: The purpose of this study was to assess the causal effect of abdominal obesity on bone mineral density by two-sample Mendelian randomization (MR).

Methods: Abdominal obesity was chosen as exposure in this study. Single nucleotide polymorphisms, extracted from Genome-wide association analysis (GWAS) data, which are closely associated with waist circumference (WC), hip circumference (HC), and waist-to-hip ratio (WHR) were used as instrumental variables to perform MR studies. Different site bone mineral density, such as total bone mineral density (TBMD) and forearm bone mineral density (FBMD) were chosen as outcomes. Inverse variance weighted (IVW) was used as the primary method to assess this causality.

Results: According to the IVW method (β = −0.177; 95% CI = −0.287, −0.067; p = 1.52 × 10^–3), WC had a negative causal relationship with TBMD, besides, with one standard deviation (SD) higher in HC, there was a 0.195 SD decrease in TBMD (95% CI = −0.279, −0.110; p = 6.32 × 10^–6), and with an increase of one SD in HC was related to a decrease of 0.312 SD in FBMD analyzed by the IVW.

Conclusion: This study showed that abdominal obesity has a negative effect on bone mineral density.

The relationship between estimated glucose disposal rate and bone turnover markers in type 2 diabetes mellitus

PURPOSE

To investigate the relationship between estimated glucose disposal rate (eGDR) and bone turnover markers in patients with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

This is a cross-sectional study, which recruited 549 patients with T2DM. The eGDRs of patients were calculated based on the presence of hypertension, glycated hemoglobin, and body mass index. All patients were divided into high-eGDR group and low-eGDR group using the median of eGDR as the boundary. The patients were further divided into two subgroups: males and postmenopausal females.

RESULTS

The lower the eGDR, the more severe was insulin resistance. The levels of osteocalcin (OC), type I collagen carboxyl-terminal peptide (β-CTX), and type I procollagen amino-terminal peptide (PINP) were significantly lower in the low-eGDR group than those in the high-eGDR group. The eGDR was positively correlated with OC, β-CTX, and PINP in all patients, and in the male subgroups. In the postmenopausal female subgroup, there was no correlation between eGDR and OC, β-CTX, or PINP. In addition, this positive correlation remained after adjusting for other factors in multilinear regression analysis.

CONCLUSION

Our study was the first to demonstrate that eGDR is positively correlated with bone turnover markers in patients with T2DM. This correlation was observed among the male patients with T2DM but not among postmenopausal female patients with T2DM.

The Relationship between Body Composition and Bone Mineral Density of Female Workers in A Unit of Tai’an

Objective. To explore the relationship between body composition and bone mineral density (BMD) of female workers in a university of Tai’an. Methods. This study randomly selected 90 female employees in a university of Tai’an. The body composition was monitored by body composition analyzer (inbody770), and the lumbar bone mineral density was monitored by dual energy X-ray absorptiometry (BMD model). The data were analyzed by SPSS 22.0 statistical software. Results. With the increasing of body mass index (BMI), BMD of female lumbar spines 1-4 (L1-4) increased gradually. Spearman correlation analysis showed that BMI, skeletal muscle mass, upper limb muscle mass, trunk muscle mass, lower limb muscle mass, and whole-body phase angle were positively correlated with L1-4BMD. Age was negatively correlated with L1-4BMD. Linear regression analysis showed that age was a negative factor of L1-4BMD, and skeletal muscle mass was a protective factor of abnormal bone mass, especially lower limb muscle mass. Conclusions. Lower limb muscle mass is a protective factor of female BMD. Strengthening physical exercise to improve lower limb muscle mass is conducive to the prevention of female osteoporosis.

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.

β-Cell function is associated with osteosarcopenia in middle-aged and older nonobese patients with type 2 diabetes: A cross-sectional study

Type 2 diabetes mellitus (T2DM) is a strong risk tfactor for osteosarcopenia. The relationship between musculoskeletal index and β-cell function remains controversial. We aimed to describe the clinical characteristics of osteosarcopenia and to explore the association between osteosarcopenia and β-cell function, as well as insulin resistance in patients with T2DM. A total of 150 middle-aged and older nonobese patients with T2DM were recruited. Bone mineral density (BMD) and body composition were measured by the dual-energy X-ray absorptiometry scanner. The homeostasis model assessment of insulin resistance and Matsuda index were used to evaluate insulin resistance status. β-Cell function was estimated by the area under the curve insulin/glucose (AUC-Ins/Glu) and the area under the curve C-peptide/glucose (AUC-CP/Glu). T2DM patients with osteosarcopenia had lower body mass index, waist circumference, body fat percentage, AUC-Ins/Glu, and AUC-CP/Glu. Both AUC-Ins/Glu (OR = 0.634, P = 0.008) and AUC-CP/Glu (OR = 0.491, P = 0.009) were negatively associated with the presence of osteosarcopenia. Multivariate linear regression analysis showed that β-cell function was positively associated with the skeletal muscle mass index, whereas it showed no correlation with lumbar or hip BMD. β-Cell function is associated with osteosarcopenia in middle-aged and older nonobese patients with T2DM. These findings suggest that β-cell function might be a protective factor against osteosarcopenia.

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.

Association of circulating C-reactive protein and high-sensitivity C-reactive protein with components of sarcopenia: A systematic review and meta-analysis of observational studies

BACKGROUND

Sarcopenia, a multi-faceted skeletal muscle disorder in the older population, has poor health outcomes. Some previous observational studies investigated the association between circulating inflammatory markers and sarcopenia components to evaluate chronic inflammation as a risk factor for sarcopenia in the elderly population. Nevertheless, the association between circulating C-reactive protein (CRP) and hs-CRP, as the recognized markers of systemic inflammation and components of sarcopenia, is unclear. This meta-analysis aimed to investigate the association of muscle strength, muscle mass, and muscle function with two serum inflammatory markers, circulating C-reactive protein (CRP) and high-sensitive CRP (hs-CRP).

METHODS

We assessed all observational studies across different electronic databases including PubMed, Scopus, and Google Scholar using keywords such as "muscle strength", "muscle mass", "muscle function", CRP and hs-CRP from inception until the 30th of July 2019. Only studies that investigated the association between components of sarcopenia and CRP or hs-CRP levels were included. Participants' country, age, sex, BMI, and screening tool for sarcopenia were retrieved. The correlations between muscle strength, muscle mass, and muscle function with CRP, and hs-CRP were expressed as the correlation coefficient (r) with 95% confidence intervals (CIs). Begg's test and Egger's test were conducted to evaluate risk of publication bias in this study.

RESULTS

Initially, we found fifty-nine studies for the qualitative synthesis. Ultimately, nineteen adult cross-sectional studies comprising 14,650 subjects were included in the meta-analysis. Of them, fourteen studies measured the correlation between CRP or hs-CRP and muscle strength. There were significant inverse correlation between CRP and hs-CRP concentrations with muscle strength (ES (z) = -0.22; 95% CI = -0.34 to -0.09; P < 0.001), (ES (z) = -0.22; 95% CI = -0.34 to -0.09; P < 0.001), respectively. No publication bias was found between muscle strength and CRP (P = 0.53) or hs-CRP (P = 0.62) respectively.

CONCLUSION

Among diagnostic components of sarcopenia, impairment of muscle strength was independently associated with both inflammatory biomarkers. However, future cohort studies are essential to clarify the causal correlation.

Impact of waist circumference on the risk of vertebral fracture: A nationwide cohort study in South Korea

Evidence on the association between abdominal obesity and vertebral fracture (VF) risk is limited. We examined the association of waist circumference (WC) and abdominal obesity with VF risk in 352,095 South Korean participants aged ≥40 years who underwent health checkups between 2009 and 2012. Abdominal obesity was defined by WC ≥90 cm in men and ≥ 85 cm in women according to the Asian-specific WC cutoff for abdominal obesity. Participants were a representative sample cohort of the Korean National Health Insurance System. The hazard ratios (HRs) and 95% CIs of VF development were determined using multivariable Cox proportional hazard regression analysis. During the 5.5 years of follow-up, there were 2030 and 4968 new cases of VF in men and women, respectively. In men, those with abdominal obesity showed an elevated HR (1.11, 95% CI: 1.01-1.23) of incident VF than did those without abdominal obesity. In women, the HRs of VF increased in higher WC groups after adjusting for confounders (P for trend <0.001); the HR decreased in those with WC <75.0 cm (HR: 0.81, 95% CI: 0.75-0.88) and increased in those with WC 85.0-89.9 cm (HR: 1.12, 95% CI: 1.02-1.22), 90.0-94.9 cm (HR: 1.19, 95% CI: 1.08-1.32), and ≥ 95.0 cm (HR: 1.27, 95% CI: 1.12-1.43) compared with those with WC 80.0-84.9 cm. This association persisted after stratification by age in women. WC and abdominal obesity were positively associated with VF risk in women, and abdominal obesity was associated with VF risk even in men. The consideration of WC and controlling abdominal obesity may be helpful in reducing future VF risk.

Association between Bone Mineral Density and Nutritional Status, Body Composition and Bone Metabolism in Older Adults

PURPOSE

To identify an association between bone mineral density (BMD) and nutritional status, body composition and bone metabolism in older patients.

METHODS

Cross-sectional study, involving older adults, with osteopenia/osteoporosis and with normal BMD. The mineral density of the lumbar spine from L1 to L4 and the proximal region of the femur was assessed using dual energy X-ray absorptiometry. Biochemical analyzes were performed of 25(OH)-D, calcium and parathormone. Weight, knee height, and abdominal (AC), mid-upper arm (MUAC) and calf (CC) circumferences were measured. The percentage of body fat (%BF) and Fat-Free Mass (FFM) were quantified by electrical bioimpedance analysis. The Body Mass Index (BMI) was calculated. The statistical analysis used bivariate and multivariate, parametric and/or non-parametric tests, and was considered significant when p <0.05.

RESULTS

Of the total 51 older adults assessed, 30 of them (58.8%) were diagnosed with osteopenia/osteoporosis. Body weight (p = 0.001), BMI (p = 0.001), % BF (p = 0.030) and serum concentrations of 25(OH)-D (p = 0.003) were higher in the group without changes in BMD. BMI and serum levels of 25(OH)-D demonstrated a positive correlation with the BMD of all bone compartments and the AC displayed a positive correlation with the lumbar vertebrae. In the logistic regression models, adjusted for sex and age, the BMI and the serum concentration of 25(OH)-D were presented as a protective factor against osteopenia/osteoporosis.

CONCLUSIONS

Higher body weight, BMI, AC and %BF, and sufficient serum levels of vitamin D, were shown to be promoters of BMD.

Correlation of Osteoporosis in Patients With Newly Diagnosed Type 2 Diabetes: A Retrospective Study in Chinese Population

This study aimed to explore the risk factors attributed to osteoporosis in newly type 2 diabetes mellitus (T2DM) patients. This study aimed to recruit 244 T2DM patients and 218 non-diabetic controls. We collected demographic characteristics, medical history, bone mineral density and biomarkers including bone specific alkaline phosphatase (BALP), osteocalcin, N-terminal peptide of type I procollagen (P1NP), tartrate-resistant acid phosphatase 5b (TRCAP-5b), β-Cross Laps of type I collagen-containing cross-linked C-telopeptide (β-CTX), 25-hydroxyvitamin D, parathyroid hormone were recorded or detected. Bone mineral density (BMD) was our primary outcome. Based on the result of BMD, we divided both the control group and T2DM group into three subgroups: normal bone mass, osteopenia and osteoporosis. In control group, we found age, sex, menopausal status, BMI, P1NP, BALP, TRACP-5b, osteocalcin, and corrected serum calcium are differential among three subgroups. In T2DM group, we found age, sex, menopausal status, drinking status, BMI, HbA1c, TRACP-5b and OC were differential among three subgroups. In T2DM and control groups, age, female, postmenopausal status, BALP, TRACP-5b and osteocalcin were positively correlated while BMI was negatively correlated with osteoporosis. In control group, β-CTX was positively correlated with osteoporosis. In T2DM group, HbA1c and corrected serum calcium concentration were positively correlated with osteoporosis. After further adjustment of age, BMI in male, TRACP-5b was positively correlated with the risk of osteoporosis in newly diagnosed T2DM. After adjusted of age, BMI and menopausal status in female, OC was positively correlated with the risk of osteoporosis in newly diagnosed T2DM and controls. In female T2DM, BALP and P1NP were positively correlated with the risk of osteoporosis. In conclusion, age, BMI and menopausal status are common risk factors for osteoporosis in diabetic and non-diabetic patients, however TRACP-5b, BALP and osteocalcin are special risk factors for osteoporosis in newly diagnosed T2DM patients but not non-diabetic patients, which may be applied to identify osteoporosis risk in T2DM patients, but this result needs to be proven with fracture data.

Lifestyle interventions for the prevention and treatment of hypertension

Hypertension affects approximately one third of the world's adult population and is a major cause of premature death despite considerable advances in pharmacological treatments. Growing evidence supports the use of lifestyle interventions for the prevention and adjuvant treatment of hypertension. In this Review, we provide a summary of the epidemiological research supporting the preventive and antihypertensive effects of major lifestyle interventions (regular physical exercise, body weight management and healthy dietary patterns), as well as other less traditional recommendations such as stress management and the promotion of adequate sleep patterns coupled with circadian entrainment. We also discuss the physiological mechanisms underlying the beneficial effects of these lifestyle interventions on hypertension, which include not only the prevention of traditional risk factors (such as obesity and insulin resistance) and improvements in vascular health through an improved redox and inflammatory status, but also reduced sympathetic overactivation and non-traditional mechanisms such as increased secretion of myokines.

Effect of Sleeve Gastrectomy on Glycometabolism via Forkhead Box O1 (FoxO1)/Lipocalin-2 (LCN2) Pathway

BACKGROUND The mechanism by which sleeve gastrectomy (SG) improves glycometabolism has remained unclear so far. Increasing evidence has demonstrated that bone is a regulator of glucose metabolism, and osteoblast-derived forkhead box O1 (FoxO1) and lipocalin-2 (LCN2) are regulators of energy metabolism. The aim of this study was to investigate whether the FOXO1/LCN2 signaling pathway is involved in the anti-diabetic effect of SG. MATERIAL AND METHODS Insulin resistance was induced in Wistar rats, which were then intraperitoneally injected with streptozotocin to induce a type 2 diabetic state. Levels of fasting blood glucose, serum insulin, HbA1c, and LCN2 were analyzed at corresponding time points after SG and sham surgeries. The expressions of FOXO1, LCN2, and the melanocortin 4 receptor (MC4R) in bone and hypothalamus were detected by immunofluorescence. FOXO1 siRNA was applied to downregulate FOXO1 expression in osteoblasts of rats. The influence of FOXO1 gene on expression of LCN2 was investigated in cultured osteoblasts by western blot and PCR. RESULTS Glucose metabolism in the SG group was significantly improved. The LCN2 expression in bone in the SG group was higher than that in the sham group, whereas FOXO1 expression in the SG group was lower than that in the sham group. The binding rate of LCN2 and MC4R in the hypothalamus was also higher in the SG group compared with that in the sham group. The downregulation of FOXO1 expression in osteoblasts was accompanied by upregulation of LCN2 expression. CONCLUSIONS These results suggest that the FOXO1/LCN2 signaling pathway participates in the anti-diabetic effect of SG.

Muscle, Bone, and Fat Crosstalk: the Biological Role of Myokines, Osteokines, and Adipokines

PURPOSE OF REVIEW

Skeletal muscle and bone are connected anatomically and physiologically, and play a crucial role in human locomotion and metabolism. Historically, the coupling between muscle and bone has been viewed in light of mechanotransduction, which dictates that the mechanical forces applied to muscle are transmitted to the skeleton to initiate bone formation. However, these organs also communicate through the endocrine system, orchestrated by a family of cytokines namely myokines (derived from myocytes) and osteokines (derived from bone cells). A third player in this biochemical crosstalk is adipose tissue and the secretion of adipokines (derived from adipocytes). In this review, we discuss the bidirectional effects of myokines and osteokines on muscle and bone metabolism, and the impact of adipokines on both of these secretory organs.

RECENT FINDINGS

Several myokines, notably, IL6, irisin, IGF-1, BDNF, myostatin, and FGF2 exert anabolic/catabolic effects on bone, while the osteokines osteocalcin and sclerostin have shown to induce muscle anabolism and catabolism, respectively. Adipokines, such as leptin, resistin, adiponectin, and TNFα (released from adipose tissue), can also modulate muscle and bone metabolism. Contrarily, exercise-mediated release of lipolytic myokines (IL6, irisin, and LIF) stimulates thermogenesis by promoting the browning of adipocytes. Myokines, osteokines, and adipokines exert autocrine/paracrine effects locally as well as through the endocrine system, to regulate muscle, bone, and fat metabolism. Reductions in physical activity and increases in energy intake, both linked with aging, leads to adipocyte hypertrophy and the recruitment of immunological cells (macrophages). In turn, this releases pro-inflammatory adipokines which induces chronic low-grade inflammation (LGI), a key player in the pathology of several diseases. However, exercise-induced stimulation of bioactive cytokines, through muscle-bone-fat crosstalk, increases muscle anabolism, bone formation, mitochondrial biogenesis, glucose utilization, and fatty acid oxidation, and attenuates chronic LGI.

Modification of Muscle-Related Hormones in Women with Obesity: Potential Impact on Bone Metabolism

Lean body mass (LBM) is a determinant of areal bone mineral density (aBMD) through its mechanical actions and quite possibly through its endocrine functions. The threefold aims of this study are: to determine the effects of obesity (OB) on aBMD and myokines; to examine the potential link between myokines and bone parameters; and to determine whether the effects of LBM on aBMD are mediated by myokines. aBMD and myokine levels were evaluated in relation to the body mass index (BMI) in 179 women. Compared with normal-weight controls (CON; n = 40), women with OB (n = 139) presented higher aBMD, myostatin and follistatin levels and lower irisin levels. Except for irisin levels, all differences between the OB and CON groups were accentuated with increasing BMI. For the whole population (n = 179), weight, BMI, fat mass (FM) and LBM were positively correlated with aBMD at all bone sites, while log irisin were negatively correlated. The proportion of the LBM effect on aBMD was partially mediated (from 14.8% to 29.8%), by log irisin, but not by follistatin or myosin. This study showed that myokine levels were greatly influenced by obesity. However, irisin excepted, myokines do not seem to mediate the effect of LBM on bone tissue.

Effect of Aerobic or Resistance Exercise, or Both, on Bone Mineral Density and Bone Metabolism in Obese Older Adults While Dieting: A Randomized Controlled Trial

Weight loss therapy of older adults with obesity is limited by weight loss-induced decrease in bone mineral density (BMD), which could exacerbate ongoing age-related bone loss and increase the risk for fractures. Therefore, it is recommended that weight loss therapy of older adults with obesity should include an intervention such as regular exercise to reduce the concomitant bone loss. However, the most appropriate exercise types to combine with weight loss therapy in this older population is unknown. In a randomized controlled trial, we performed a head-to-head comparison of aerobic or resistance exercise, or both, during matched ~10% weight loss in 160 older adults with obesity. We measured changes in BMD (total hip, femoral neck, trochanter, intertrochanter, one-third radius, lumbar spine) and bone markers. Changes between groups were analyzed using mixed-model repeated measures analyses of variance. After 6 months of intensive lifestyle interventions, BMD decreased less in the resistance group (-0.006 g/cm² [-0.7%]) and combination group (-0.012 g/cm² [-1.1%]) than in the aerobic group (-0.027 g/cm² [-2.6%]) (p = 0.001 for between-group comparisons). Serum C-telopeptide, procollagen type 1 N-propeptide, and osteocalcin concentrations increased more in the aerobic group (33%, 16%, and 16%, respectively) than in the resistance group (7%, 2%, and 0%, respectively) and combination group (11%, 2%, and 5%, respectively) (p = 0.004 to 0.048 for between-group comparisons). Multiple regression analyses revealed that the decline in whole body mass and serum leptin were the independent predictors of the decline in hip BMD (multiple R = 0.45 [p < .001]). These findings indicate that compared with aerobic exercise, resistance and combined aerobic and resistance exercise are associated with less weight loss-induced decrease in hip BMD and less weight loss-induced increase in bone turnover. Therefore, both resistance and combined aerobic and resistance exercise can be recommended to protect against bone loss during weight loss therapy of older adults with obesity. (LITOE ClinicalTrials.gov number NCT01065636.) © 2019 American Society for Bone and Mineral Research. Published 2019. This article is a U.S. Government work and is in the public domain in the USA.

Myokines: The endocrine coupling of skeletal muscle and bone

Bone and skeletal muscle are integrated organs and their coupling has been considered mainly a mechanical one in which bone serves as attachment site to muscle while muscle applies load to bone and regulates bone metabolism. However, skeletal muscle can affect bone homeostasis also in a non-mechanical fashion, i.e., through its endocrine activity. Being recognized as an endocrine organ itself, skeletal muscle secretes a panel of cytokines and proteins named myokines, synthesized and secreted by myocytes in response to muscle contraction. Myokines exert an autocrine function in regulating muscle metabolism as well as a paracrine/endocrine regulatory function on distant organs and tissues, such as bone, adipose tissue, brain and liver. Physical activity is the primary physiological stimulus for bone anabolism (and/or catabolism) through the production and secretion of myokines, such as IL-6, irisin, IGF-1, FGF2, beside the direct effect of loading. Importantly, exercise-induced myokine can exert an anti-inflammatory action that is able to counteract not only acute inflammation due to an infection, but also a condition of chronic low-grade inflammation raised as consequence of physical inactivity, aging or metabolic disorders (i.e., obesity, type 2 diabetes mellitus). In this review article, we will discuss the effects that some of the most studied exercise-induced myokines exert on bone formation and bone resorption, as well as a brief overview of the anti-inflammatory effects of myokines during the onset pathological conditions characterized by the development a systemic low-grade inflammation, such as sarcopenia, obesity and aging.

High dose vitamin D supplementation does not rescue bone loss following Roux-en-Y gastric bypass in female rats

Postoperative bone loss and increased fracture risk associated with Roux-en-Y gastric bypass (RYGB) have been attributed to vitamin D/calcium malabsorption and resultant secondary hyperparathyroidism (HPT). Adequate vitamin D supplementation (VDS), particularly in an older female population, reduces incidence of secondary HPT but the effect on bone loss and fracture risk remains unclear. To investigate whether VDS corrects the RYGB bone phenotype, 41 obese adult female rats were randomized to RYGB with 1000 IU (R1000) or 5000 IU (R5000) vitamin D/kg food or a sham surgical procedure with either paired (PF) or ad libitum (AL) feeding. Bone turnover markers, urinary calcium/creatinine ratio (CCR), and serum calciotropic and gut hormones were assessed throughout a 14-week postoperative period. Femurs were analyzed by micro-computed tomography (μCT), three-point bending test, and histomorphometry. 1000 IU animals had low 25‑hydroxyvitamin D (25(OH)D), high serum parathyroid hormone (PTH), and very low urine CCR levels. 5000 IU corrected the 25(OH)D and secondary HPT but did not increase urine CCR or serum levels of 1,25‑dihydroxyvitamin D (1,25(OH)D) significantly between RYGB groups. Compared to sham animals at 14 weeks, RYGB animals had significantly higher serum osteocalcin (OCN) and C-terminal telopeptide (CTX) levels. The gut hormone peptide tyrosine tyrosine hormone (PYY) was higher in the RYGB groups, and leptin was lower. μCT and biomechanical testing revealed RYGB females had decreased cortical and trabecular bone volume and weaker, stiffer bone than controls. Histomorphometry showed decreased bone volume and increased osteoid volume with increased mineral apposition rate in RYGB compared to controls. No differences in bone phenotype were identified between 1000 IU and 5000 IU groups, and osteoclast numbers were comparable across all four groups. Thus, in our model, 5000 IU VDS corrected vitamin D deficiency and secondary HPT but did not rescue RYGB mineralization rate nor the osteomalacia phenotype. Longer studies in this model are required to evaluate durability of these detrimental effects. Our findings not only underscore the importance of lifelong repletion of both calcium and vitamin D but also suggest that additional factors affect skeletal health in this population.

'Obesageing': Linking obesity & ageing

Obesity is one of the leading causes of preventable mortalities in many parts of the globe. The rise in geriatric population due to better treatment opportunities has also emerged as a major public health challenge. Both of these health challenges have impacted developed as well as developing countries. Obesity is attributed as a powerful risk factor of a variety of health problems such as cardiovascular diseases, hypertension, type 2 diabetes, dementia, neuropsychiatric diseases and many more. On the other hand, ageing is a natural process involving a gradual decline in physiological functions and is associated with similar co-morbidities as obesity. This review discusses about the commonalities (termed as ‘Obesageing') between the pathological phenomenon of obesity and normal physiological process of ageing. A unique rodent model of obesageing has been developed (WNIN/Ob) that has characteristics of morbid obesity as well as premature ageing. Such a novel animal model would facilitate the understanding of the complex interplay of different mechanisms that are common to obesity and ageing and help to devise strategies in future to tackle the growing burden of obesity and ageing.

Inhibition of the sodium-glucose co-transporter 2 in the elderly: clinical and mechanistic insights into safety and efficacy

The prevalence of type 2 diabetes mellitus (T2DM) in the elderly grew sharply over the last decade. Reduced insulin sensitivity and secretory capacity, weight gain, sarcopenia, and elevated adiposity are all common metabolic and body changes in the aging population that favor an increased risk of hypoglycemia, frailty syndrome, falls, and cognitive dysfunction. First line antidiabetic therapy is frequently not safe in older individuals because of its high risk of hypoglycemia and prevalent co-morbid diseases, such as chronic kidney disease, osteoporosis, cardiovascular disease, and obesity. Sodium-glucose cotransporter 2 inhibitor (SGLT2i) is a new class of antidiabetic therapy that inhibits glucose and sodium reabsorption on renal proximal convoluted tubule. Its effect is well demonstrated in various clinical scenarios in the younger population. This review and metanalysis describe particularities of the SGLT2i on the elderly, with mechanistic insights of the potential benefit and remaining challenges about the use of these drugs in this important age group. Further, we will present a meta-analysis of the main effects of SGLT2i reported in post-hoc studies in which the median age of the subgroups analyzed was over 60 years. Despite the absence of specific clinical trials for this population, our findings suggest that SGLT2i therapy on older individuals is effective to lower glucose and maintain its effect on systolic blood pressure and body weight.

Update on the impact of type 2 diabetes mellitus on bone metabolism and material properties

The prevalence of type 2 diabetes mellitus (T2DM) is increasing worldwide, especially as a result of our aging society, high caloric intake and sedentary lifestyle. Besides the well-known complications of T2DM on the cardiovascular system, the eyes, kidneys and nerves, bone strength is also impaired in diabetic patients. Patients with T2DM have a 40-70% increased risk for fractures, despite having a normal to increased bone mineral density, suggesting that other factors besides bone quantity must account for increased bone fragility. This review summarizes the current knowledge on the complex effects of T2DM on bone including effects on bone cells, bone material properties and other endocrine systems that subsequently affect bone, discusses the effects of T2DM medications on bone and concludes with a model identifying factors that may contribute to poor bone quality and increased bone fragility in T2DM.

Metabolic effects of antidiabetic drugs on adipocytes and adipokine expression

Several classes of antidiabetic agents have been developed that achieve their hypoglycemic outcomes via various molecular mechanisms. Adipose tissue is a major metabolic and energy-storing tissue and plays an important role in many metabolic pathways, including insulin signaling and insulin sensitivity. Adipose tissue monitors and regulates whole body homeostasis via production and release of potent proteins, such as adipokine and adiponectin, into the circulation. Therefore, any agent that can modulate adipocyte metabolism can, in turn, affect metabolic and glucose homeostatic pathways. Antidiabetic drugs are not only recognized primarily as hypoglycemic agents but may also alter adipose tissue itself, as well as adipocyte-derived adipokine expression and secretion. In the current review, we present the major evidence concerning routinely used antidiabetic agents on adipocyte metabolism and adipokine expression.

Weight Loss-Induced Reduction of Bone Mineral Density in Older Adults with Obesity

Obesity in older adults is a growing public health problem, yet the appropriate treatment remains controversial partly due to evidence that weight loss reduces bone mass and may increase fracture risk. The purpose of this review is to summarize the research to date on the effects of diet-induced weight loss on bone health in obese (body mass index 30 kg/m² and above) older (aged 65 years or older) adults. Observational studies have shown that weight loss in this population decreases total hip bone mineral density and increases the risk of frailty fractures (composite of proximal femur, pelvis, and proximal humerus fractures). Randomized controlled trials have largely confirmed these earlier observations but have also shown that exercise, particularly progressive resistance training, can attenuate or even alleviate this bone loss. Further research incorporating outcomes concerning bone quality and mass are needed to identify the optimal exercise and nutritional regimens to counteract the bone loss.

Increased adiposity, inflammation, metabolic disruption and dyslipidemia in adult male offspring of DOSS treated C57BL/6 dams

Evidence indicates that obesity can be promoted by chemical ‘obesogens’ that drive adiposity, hunger, inflammation and suppress metabolism. Dioctyl sodium sulfosuccinate (DOSS), a lipid emulsifier and candidate obesogen in vitro, is widely used in processed foods, cosmetics and as stool softener medicines commonly used during pregnancy. In vivo testing of DOSS was performed in a developmental origins of adult obesity model. Pregnant mice were orally administered vehicle control or DOSS at times and doses comparable to stool softener use during human pregnancy. All weaned offspring consumed only standard diet. Adult male but not female offspring of DOSS-treated dams showed significantly increased body mass, overall and visceral fat masses, and decreased bone area. They exhibited significant decreases in plasma adiponectin and increases in leptin, glucose intolerance and hyperinsulinemia. Inflammatory IL-6 was elevated, as was adipose Cox2 and Nox4 gene expressions, which may be associated with promoter DNA methylation changes. Multiple significant phospholipid/sterol lipid increases paralleled profiles from long-term high-fat diet induced obesity in males. Collectively, developmental DOSS exposure leads to increased adult adiposity, inflammation, metabolic disorder and dyslipidemia in offspring fed a standard diet, suggesting that pharmaceutical and other sources of DOSS taken during human pregnancy might contribute to long-term obesity-related health concerns in offspring.

Physical Activity and Bone Health: What Is the Role of Immune System? A Narrative Review of the Third Way

Bone tissue can be seen as a physiological hub of several stimuli of different origin (e.g., dietary, endocrine, nervous, immune, skeletal muscle traction, biomechanical load). Their integration, at the bone level, results in: (i) changes in mineral and protein composition and microarchitecture and, consequently, in shape and strength; (ii) modulation of calcium and phosphorous release into the bloodstream, (iii) expression and release of hormones and mediators able to communicate the current bone status to the rest of the body. Different stimuli are able to act on either one or, as usual, more levels. Physical activity is the key stimulus for bone metabolism acting in two ways: through the biomechanical load which resolves into a direct stimulation of the segment(s) involved and through an indirect load mediated by muscle traction onto the bone, which is the main physiological stimulus for bone formation, and the endocrine stimulation which causes homeostatic adaptation. The third way, in which physical activity is able to modify bone functions, passes through the immune system. It is known that immune function is modulated by physical activity; however, two recent insights have shed new light on this modulation. The first relies on the discovery of inflammasomes, receptors/sensors of the innate immunity that regulate caspase-1 activation and are, hence, the tissue triggers of inflammation in response to infections and/or stressors. The second relies on the ability of certain tissues, and particularly skeletal muscle and adipose tissue, to synthesize and secrete mediators (namely, myokines and adipokines) able to affect, profoundly, the immune function. Physical activity is known to act on both these mechanisms and, hence, its effects on bone are also mediated by the immune system activation. Indeed, that immune system and bone are tightly connected and inflammation is pivotal in determining the bone metabolic status is well-known. The aim of this narrative review is to give a complete view of the exercise-dependent immune system-mediated effects on bone metabolism and function.

Adipocytes ESR1 Expression, Body Fat and Response to Testosterone Therapy in Hypogonadal Men Vary According to Estradiol Levels

Estradiol (E2), mainly produced from Testosterone (T) in men, promotes visceral lipolysis. However, high visceral fat and hyperestrogenemia are features of obese hypogonadal (HG) men. Our study objectives are to evaluate relationships between circulating E2 and: (1) fat mass; (2) Estrogen Receptor α (ESR1) expression in subcutaneous adipose tissue; (3) changes in body fat after 6 months (M) of T therapy in HG men.

HYPOTHESES

(1) existence of a range of circulating E2 associated with better body composition; (2) serum E2 determines tissue E2 sensitivity which affects response to T therapy. Men 40⁻74 years old, T < 300 (ng/dL), given T-cypionate for 6 months. Subjects were divided into 4-E2 categories: (1) <10.0; (2) 10.0⁻15.9; (3) 16.0⁻19.9; (4) ≥20.0 (pg/mL). Body composition (DXA), fat biopsies (liposuction), gene expression (qPCR), serum E2 and T (LC/MS), at baseline and 6 months. We enrolled 105 men; 90 completed the study. Group 2 had lower total and truncal fat mass (p < 0.01) but higher % lean mass (p < 0.001). ESR1 mRNA was the highest in group 1 (p = 0.01). At 6 months, group 1 had higher reduction in total (p = 0.03) and truncal (p = 0.01) fat. In conclusion, serum E2 = 10⁻15.9 (pg/mL) is associated with the best body composition profile in HG men; however, those with E2 < 10 (pg/mL) had the best response (greater fat loss) to T replacement possibly because of greater E2 sensitivity.

Lifestyle Management of Diabetes: Implications for the Bone-Vascular Axis

PURPOSE OF REVIEW

To describe the main pathways involved in the interplay between bone and cardiovascular disease and to highlight the possible impact of physical activity and medical nutrition therapy on the bone-vascular axis.

RECENT FINDINGS

Diabetes increases the risk of both cardiovascular disease and bone fragility fractures, sharing common pathogenic pathways, including OPG/RANK/RANKL, the FGF23/Klotho axis, calciotropic hormones, and circulating osteogenic cells. This may offer new therapeutic targets for future treatment strategies. As lifestyle intervention is the cornerstone of diabetes treatment, there is potential for an impact on the bone-vascular axis. Evidence published suggests the bone-vascular axis encompasses key pathways for cardiovascular disease. This, along with studies showing physical activity plays a crucial role in the prevention of both bone fragility and cardiovascular disease, suggests that lifestyle intervention incorporating exercise and diet may be helpful in managing skeletal health decline in diabetes. Studies investigating the controversial role of high-fiber diet and dietary vitamin D/calcium on bone and cardiovascular health suggest an overall benefit, but further investigations are needed in this regard.

Differential effects of high fat diet and diet-induced obesity on skeletal acquisition in female C57BL/6J vs. FVB/NJ Mice

The effects of obesity on bone metabolism are complex, and may be mediated by consumption of a high fat diet and/or by obesity-induced metabolic dysregulation. To test the hypothesis that both high fat (HF) diet and diet-induced metabolic disease independently decrease skeletal acquisition, we compared effects of HF diet on bone mass and microarchitecture in two mouse strains: diet-induced obesity (DIO)-susceptible C57BL/6J (B6) and DIO-resistant FVB/NJ (FVB). At 3 wks of age we weaned 120 female FVB and B6 mice onto normal (N, 10% Kcal/fat) or HF diet (45% Kcal/fat) and euthanized them at 6, 12 and 20 weeks of age (N = 10/grp). Outcomes included body mass; percent fat and whole-body bone mineral density (WBBMD, g/cm2) via DXA; cortical and trabecular bone architecture at the midshaft and distal femur via μCT; and marrow adiposity via histomorphometry. In FVB HF, body mass, percent body fat, WBBMD and marrow adiposity did not differ vs. N, but trabecular bone mass was lower at 6 wks of age only (p < 0.05), cortical bone geometric properties were lower at 12 wks only, and bone strength was lower at 20 wks of age only in HF vs. N (p < 0.05). In contrast, B6 HF had higher body mass, percent body fat, and leptin vs. N. B6 HF also had higher WBBMD (p < 0.05) at 9 and 12 wks of age but lower distal femur trabecular bone mass at 12 wks of age, and lower body mass-adjusted cortical bone properties at 20 wks of age compared to N (p < 0.05). Marrow adiposity was also markedly higher in B6 HF vs. N. Overall, HF diet negatively affected bone mass in both strains, but was more deleterious to trabecular bone microarchitecture and marrow adiposity in B6 than in FVB mice. These data suggest that in addition to fat consumption itself, the metabolic response to high fat diet independently alters skeletal acquisition in obesity.

Waist circumference is an effect modifier of the association between bone mineral density and glucose metabolism

OBJECTIVE

The role of bone markers on insulin resistance (IR) remains controversial. The objective of this study is to evaluate the association between bone mineral density (BMD) and glucose metabolism and investigate if visceral hyperadiposity, evaluated by waist circumference (WC), is an effect modifier of this association.

SUBJECTS AND METHODS

Cross-sectional analysis with 468 young adults from the fourth follow-up of the 1978/79 Ribeirão Preto prospective birth cohort, Brazil. BMD, total osteocalcin (OC), fasting plasma glucose and insulin concentrations were assessed. IR, sensitivity (S) and secretion (β) were estimated by homeostasis model assessment (HOMA) indexes. Multiple linear regression models were constructed to estimate the association between BMD and glucose metabolism. Beta coefficient, R2 and p-values were provided. WC was tested as an effect modifier and OC as a confounder. The covariates were selected based on Direct Acyclic Graph.

RESULTS

Significant interaction between BMD (femoral neck and proximal femur areas) and WC on glucose metabolism was observed in the adjusted models. Subjects with increased WC presented a positive association between BMD and log HOMA1-IR while an inverse association was found in those with normal WC (femoral neck R2 = 0.17, p = 0.036; proximal femur R2 = 0.16, p = 0.086). BMD was negatively associated with log HOMA2-S in individuals with increased WC and positively in those with normal WC (femoral neck R2 = 0.16, p = 0.042; proximal femur R2 = 0.15, p = 0.097). No significant associations between BMD, log HOMA2-β and OC and glucose metabolism markers were observed.

CONCLUSIONS

BMD was associated with glucose metabolism, independently of OC, and WC modifies this association.

Progranulin concentration in relation to bone mineral density among obese individuals

OBJECTIVE

Adipose tissue, particularly visceral adipose tissue, secretes a variety of cytokines, among which progranulin is a glycoprotein related to the immune system. Along with other secreted proteins, progranulin may be associated with bone mineral density. The aim of this study was to find out whether there are associations between the progranulin and bone mineral density among obese people.

SUBJECTS AND METHODS

This cross-sectional study was conducted on 244 obese participants (aged 22-52). Serum progranulin, high sensitive C-reactive protein, oxidised-low dencity lipoprotein, tumor necrosis factor-α, parathormone, vitamin D, and interleukins of 1 β, 4, 6, 10, 13, and 17 concentrations were measured. Anthropometric measurements, body composition and bone mineral density were also assessed.

RESULTS

Serum progranulin was directly associated with interleukin-6 and interleukin-1β, while it had a negative association with interleukin-17 and tumor necrosis factor-α. We also observed a statistically significant direct association between progranulin concentration and visceral fat, abdominal fat, waist, abdominal and hip circumferences, hip T-score, and Z-score and T-score for the lumbar region. A partial correlation test has also shown a significant positive correlation regarding serum progranulin and the hip Z-score. Moreover, progranulin level is inversely associated with ospteopenia (P = 0.04 and CI: 0.17,0.96).

CONCLUSION

Our study revealed that central obesity may be related to increased progranulin concentration. In addition, progranulin concentration was directly related to bone formation parameters, which indicates the protective effects of progranulin on bone density. Further studies are needed to clarify the exact mechanisms underlying these associations.

Insulin resistance and bone: a biological partnership

Despite a clear association between type 2 diabetes (T2D) and fracture risk, the pathogenesis of bone fragility in T2D has not been clearly elucidated. Insulin resistance is the primary defect in T2D. Insulin signalling regulates both bone formation and bone resorption, but whether insulin resistance can affect bone has not been established. On the other hand, evidence exists that bone might play a role in the regulation of glucose metabolism. This article reviews the available experimental and clinical evidence on the interplay between bone and insulin resistance. Interestingly, a bilateral relationship between bone and insulin resistance seems to exist that unites them in a biological partnership.

IKKβ is a β-catenin kinase that regulates mesenchymal stem cell differentiation

Mesenchymal stem cells (MSCs) can give rise to both adipocytes and osteoblasts, but the molecular mechanisms underlying MSC fate determination remain poorly understood. IκB kinase β (IKKβ), a central coordinator of inflammation and immune responses through activation of NF-κB, has been implicated as a critical molecular link between obesity and metabolic disorders. Here, we show that IKKβ can reciprocally regulate adipocyte and osteoblast differentiation of murine and human MSCs through an NF-κB-independent mechanism. IKKβ is a β-catenin kinase that phosphorylates the conserved degron motif of β-catenin to prime it for β-TrCP-mediated ubiquitination and degradation, thereby increasing adipogenesis and inhibiting osteogenesis in MSCs. Animal studies demonstrated that deficiency of IKKβ in BM mesenchymal stromal cells increased bone mass and decreased BM adipocyte formation in adult mice. In humans, IKKβ expression in adipose tissue was also positively associated with increased adiposity and elevated β-catenin phosphorylation. These findings suggest IKKβ as a key molecular switch that regulates MSC fate, and they provide potentially novel mechanistic insights into the understanding of the cross-regulation between the evolutionarily conserved IKKβ and Wnt/β-catenin signaling pathways. The IKKβ-Wnt axis we uncovered may also have important implications for development, homeostasis, and disease pathogenesis.

Influence of adipose tissue mass on bone mass in an overweight or obese population: systematic review and meta-analysis

Context

The scientific literature shows conflicting evidence about the relationship between adiposity and bone mass in overweight and obese populations. The aim of this review was to quantify the correlation between adipose mass (absolute and relative) and bone mineral density (BMD) in overweight and obese populations. Three databases were searched electronically. In addition, reference lists of relevant articles were screened. A total of 16 studies, comprising 2587 participants and 75 correlation coefficients were selected for inclusion in the review. Data were extracted from each study using a standardized form. Multilevel modeling indicated opposing relationships between BMD and adiposity: absolute adiposity correlated positively, and relative adiposity negatively, with BMD. Sex and age were the primary moderators of these relationships. Strong evidence supported a negative relationship between relative adipose mass and BMD in men (R = -0.37; 95%CI, -0.57 to -0.12) and in those aged less than 25 years (R = -0.28; 95%CI, -0.45 to -0.08). To prevent bone loss in overweight and obese populations, nutrition- and exercise-based interventions that focus on a controlled reduction of adipose mass with concomitant preservation of lean mass are recommended. : PROSPERO no. CRD42015024313.

Bariatric Roux-En-Y Gastric Bypass Surgery: Adipocyte Proteins Involved in Increased Bone Remodeling in Humans

PURPOSE

Bariatric surgery has been associated with bone remodeling changes. The action of adipokines on the expression of receptor activator of nuclear factor kappa β ligand (RANKL) and osteoprotegerin (OPG) and on an increase in sclerostin could be related to these changes.

MATERIALS AND METHODS

This study aimed to assess the repercussions of weight loss, fat mass (FM), and fat-free mass (FFM) loss and biochemical and hormonal changes on bone remodeling markers after Roux-en-Y gastric bypass (RYGB). Anthropometric data, parathyroid hormone (PTH), bone-specific alkaline phosphatase (BSAP), collagen type 1 C-telopeptide (CTX), 25-hydroxy vitamin D (25-OH-VitD), leptin, adiponectin, RANKL, OPG, and sclerostin of 30 menstruating women were measured preoperatively (Pre), and 3, 12, and 24 months (m) after RYGB.

RESULTS

Leptin (34.4 (14.7; 51.9) vs. 22.5 (1.9; 52.7) ng/mL) and OPG (3.6 (1.1; 11.5) vs. 3.4 (1.5; 6) pmol/L) decreased, and adiponectin (7.4 (1.7; 18.4) vs. 13.8 (3.0; 34.6) μg/mL), CTX (0.2 (0.1; 2.2) vs. 0.6 (0.4; 6.0) ng/mL), RANKL (0.1 (0.0; 0.5) vs. 0.3 (0.0; 2.0) pmol/L), and sclerostin (21.7 (3.2; 75.1) vs. 34.8 (6.4; 80.5) pmol/L) increased after 3 m. BSAP increased after 12 m (10.1 (5.4; 18.9) vs. 13.9 (6.9; 30.2) μg/mL) (p < 0.005). CTX correlated positively with adiponectin at 24 m and inversely with leptin Pre; OPG at 3 m; weight, FM, FFM, and leptin at 24 m. RANKL correlated directly with weight at 3 m. Sclerostin correlated inversely with weight Pre and FM at 3 m. BSAP correlated negatively with 25-OH-VitD at 12 m, and positively with PTH at 24 m.

CONCLUSIONS

RYGB induced weight loss, and biochemical, hormonal, and body composition changes are associated with higher bone remodeling.

Fat Mass Follows a U-Shaped Distribution Based on Estradiol Levels in Postmenopausal Women

OBJECTIVE

Estradiol (E2) regulates adipose tissue resulting in increased fat mass (FM) with declining E2. However, increased visceral fat and hyperestrogenemia are features of obese individuals. It is possible that adipocytes in obese individuals are less sensitive to E2 resulting in higher FM. Our objective is to identify the range of serum E2 for which postmenopausal women have the lowest FM and best body composition.

METHODS

Cross-sectional data from 252 community-dwelling postmenopausal women, 42-90 years old. Subjects were stratified into categories of E2 (pg/ml): (1) ≤10.5; (2) 10.6-13.9; (3) 14.0-17.4; and (4) ≥17.5. Body composition by dual-energy X-ray absorptiometry. Serum E2 by radioimmunoassay. Between-group comparisons by analysis of covariance.

RESULTS

E2 linearly increased with increasing body weight and body mass index (r = 0.15 and p = 0.01 for both), but not with total FM (kg) or % FM (r = 0.07, p = 0.34 and r = -0.04, p = 0.56, respectively). However, total FM (kg) followed a U-shaped distribution and was significantly lower in group 3 (27.6 ± 10.6), compared with groups 1: (34.6 ± 12.5), 2: (34.0 ± 12.4), and 4: (37.0 ± 10.6), p = 0.005. % FM was also lowest in group 3. While fat-free mass (FFM, kg) increased with increasing E2 (p < 0.001), % FFM was highest in group 3.

CONCLUSION

In our population of postmenopausal women, FM followed a U-shaped distribution according to E2 levels. E2 between 14.0 and 17.4 pg/ml is associated with the best body composition, i.e., lowest total and % FM and highest % FFM. Given the role of E2 in regulating body fat, high FM at the high end of the E2 spectrum may suggest reduced E2 sensitivity in adipocytes among obese postmenopausal women.

CLINICAL TRIALS

ClinicalTrials.gov identifier: NCT00146107.

A meta-analysis of the association between body mass index and risk of vertebral fracture

We conducted a meta-analysis of prospective studies to assess the association between BMI and incident vertebral fracture. We found that as body mass index (BMI) increases, the risk of vertebral fracture decreases in men, but not in women, suggesting possible gender differences in the relationship of BMI with risk of vertebral fracture.

INTRODUCTION

Recent evidence suggests that the relationship between BMI and fracture risk may be site-specific. We conducted a systematic review and meta-analysis of prospective studies to investigate the association between BMI and risk of incident vertebral fracture.

METHODS

PubMed and Embase were searched for relevant articles published from inception through February 15, 2017. Extracted relative risks (RR) from the prospective studies were pooled using random-effects meta-analysis.

RESULTS

Six studies were included, with a total of 105,129 participants followed for 3 to 19 years. The pooled RR (95% confidence interval [CI]) for vertebral fracture per each standard deviation increase in BMI was 0.94 (95% CI = 0.80-1.10) with significant heterogeneity (I ² = 88.0%, p < 0.001). In subgroup analysis by gender, we found a significant inverse association between BMI and risk of vertebral fracture in men (RR = 0.85, 95% CI = 0.73-0.98, n = 25,617 participants) but not in women (RR = 0.98, 95% CI = 0.81-1.20, n = 79,512 participants). Across studies of women not adjusting for bone mineral density (BMD), there was no significant association between BMI and risk of vertebral fracture (RR = 0.91, 95% CI = 0.80-1.04, p = 0.18, n = 72,755 participants). However, BMI was associated with an increased risk of vertebral fracture in studies of women that adjusted for BMD (RR = 1.28, 95% CI = 1.17-1.40, p < 0.001, n = 6757 participants). Substantial heterogeneity was found among studies of women (I ² = 90.1%, p < 0.001), which was partly explained by the adjustment for BMD (adjusted R ² = 61%). We found no evidence of publication bias (p = 0.40).

CONCLUSIONS

In conclusion, our findings suggest that there might be gender differences in the relationship of BMI with risk of vertebral fracture. Further research is needed, including the assessment of other measures of adiposity, such as visceral adiposity, on the risk of vertebral fracture.

Hypogonadal Men with Higher Body Mass Index have Higher Bone Density and Better Bone Quality but Reduced Muscle Density

Although hypogonadism is a risk factor for bone loss and fractures, the different etiopathophysiology and hormonal profile of classical and obesity-induced hypogonadism may lead to differences in musculoskeletal profile. This is a cross-sectional study of hypogonadal men between 40 and 74 years old. Our outcomes include: areal bone mineral density (aBMD) and body composition by dual-energy X-ray absorptiometry; volumetric BMD (vBMD) and soft tissue composition of the tibia by peripheral quantitative computed tomography. Fracture risk assessment tool (FRAX) scores were evaluated. Testosterone, estradiol, luteinizing hormone, follicle stimulating hormone, sex hormone-binding globulin, C-telopeptide, osteocalcin, and sclerostin were measured. We divided the population into subgroups of BMI: group 1: BMI < 30; group 2: BMI ≥30 to <35 and group 3: BMI ≥ 35 kg/m². One-hundred five men were enrolled. Spine and hip aBMD, and total and trabecular vBMD at the 4% tibia significantly increased with increasing BMI. Cortical thickness (330.7 ± 53.2, 343.3 ± 35.4, and 358.7 ± 38.2 mm, p = 0.04; groups 1, 2 and 3, respectively) and cortical area (5.3 ± 0.7, 5.5 ± 0.6, and 5.7 ± 0.6 mm, p = 0.01; groups 1, 2 and 3, respectively) at 38% tibia increased with increasing BMI. While absolute lean mass increased with increasing BMI, % lean mass and muscle density (70.2 ± 5.0, 71.3 ± 6.4, and 67.1 ± 5.1 mg/cm³; groups 1, 2 and 3, respectively) were lowest in group 3. Although severely obese hypogondal men have better BMD and bone quality, they have reduced muscle density, the significance of which remains to be determined.

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.

Mechanical signals protect stem cell lineage selection, preserving the bone and muscle phenotypes in obesity

The incidence of obesity is rapidly rising, increasing morbidity and mortality rates worldwide. Associated comorbidities include type 2 diabetes, heart disease, fatty liver disease, and cancer. The impact of excess fat on musculoskeletal health is still unclear, although it is associated with increased fracture risk and a decline in muscular function. The complexity of obesity makes understanding the etiology of bone and muscle abnormalities difficult. Exercise is an effective and commonly prescribed nonpharmacological treatment option, but it can be difficult or unsafe for the frail, elderly, and morbidly obese. Exercise alternatives, such as low-intensity vibration (LIV), have potential for improving musculoskeletal health, particularly in conditions with excess fat. LIV has been shown to influence bone marrow mesenchymal stem cell differentiation toward higher-order tissues (i.e., bone) and away from fat. While the exact mechanisms are not fully understood, recent studies utilizing LIV both at the bench and in the clinic have demonstrated some efficacy. Here, we discuss the current literature investigating the effects of obesity on bone, muscle, and bone marrow and how exercise and LIV can be used as effective treatments for combating the negative effects in the presence of excess fat.

The role of sex and body weight on the metabolic effects of high-fat diet in C57BL/6N mice

BACKGROUND

Metabolic disorders are commonly investigated using knockout and transgenic mouse models on the C57BL/6N genetic background due to its genetic susceptibility to the deleterious metabolic effects of high-fat diet (HFD). There is growing awareness of the need to consider sex in disease progression, but limited attention has been paid to sexual dimorphism in mouse models and its impact in metabolic phenotypes. We assessed the effect of HFD and the impact of sex on metabolic variables in this strain.

METHODS

We generated a reference data set encompassing glucose tolerance, body composition and plasma chemistry data from 586 C57BL/6N mice fed a standard chow and 733 fed a HFD collected as part of a high-throughput phenotyping pipeline. Linear mixed model regression analysis was used in a dual analysis to assess the effect of HFD as an absolute change in phenotype, but also as a relative change accounting for the potential confounding effect of body weight.

RESULTS

HFD had a significant impact on all variables tested with an average absolute effect size of 29%. For the majority of variables (78%), the treatment effect was modified by sex and this was dominated by male-specific or a male stronger effect. On average, there was a 13.2% difference in the effect size between the male and female mice for sexually dimorphic variables. HFD led to a significant body weight phenotype (24% increase), which acts as a confounding effect on the other analysed variables. For 79% of the variables, body weight was found to be a significant source of variation, but even after accounting for this confounding effect, similar HFD-induced phenotypic changes were found to when not accounting for weight.

CONCLUSION

HFD and sex are powerful modifiers of metabolic parameters in C57BL/6N mice. We also demonstrate the value of considering body size as a covariate to obtain a richer understanding of metabolic phenotypes.

Mechanisms of diabetes mellitus-induced bone fragility

The risk of fragility fractures is increased in patients with either type 1 diabetes mellitus (T1DM) or type 2 diabetes mellitus (T2DM). Although BMD is decreased in T1DM, BMD in T2DM is often normal or even slightly elevated compared with an age-matched control population. However, in both T1DM and T2DM, bone turnover is decreased and the bone material properties and microstructure of bone are altered; the latter particularly so when microvascular complications are present. The pathophysiological mechanisms underlying bone fragility in diabetes mellitus are complex, and include hyperglycaemia, oxidative stress and the accumulation of advanced glycation endproducts that compromise collagen properties, increase marrow adiposity, release inflammatory factors and adipokines from visceral fat, and potentially alter the function of osteocytes. Additional factors including treatment-induced hypoglycaemia, certain antidiabetic medications with a direct effect on bone and mineral metabolism (such as thiazolidinediones), as well as an increased propensity for falls, all contribute to the increased fracture risk in patients with diabetes mellitus.