Mechanisms Involved in Childhood Obesity-Related Bone Fragility

Impact of high fat and low lean mass phenotype on bone mineral content: A cross-sectional study of Chinese adolescent population

BACKGROUND AND OBJECTIVE

Research on body composition phenotypes and bone health in adolescents is limited. Hence, this study aimed to analyze the relationship between different body composition phenotypes, bone mineral content, and bone metabolism markers in Chinese adolescents.

METHODS

In this cross-sectional study, 1852 adolescents aged 12 to 18 years were selected from six schools in Yinchuan City between 2017 and 2020 using stratified cluster random sampling. The participant's body composition and bone mineral content (BMC) were measured using bioelectrical impedance analysis (BIA). Serum bone metabolic markers (OC, CTX, and Ca) were measured. Based on their FMI and LMI, individuals were categorized into four body composition phenotypes: low fat mass-low lean mass (LFMI-LLMI), low fat mass-high lean mass (LFMI-HLMI), high fat mass-high lean mass (HFMI-HLMI), high fat mass-low lean mass (HFMI-LLMI).

RESULTS

There was a statistically significant difference between the four different body composition phenotypes with BMC, CTX and Ca in boys (all P < 0.05), similar conclusions were found in girls, except the OC and CTX. After adjusting for age, gender, smoking, drinking, and others, compared with the LFMI-HLMI reference group, the two high FMI groups (HFMI-LLMI and HFMI-HLMI) had a greater negative correlation with BMC, while the low BMC risk of the HFMI-LLMI group was the highest (OR = 33.28; 95%CI: 11.12-99.63; P < 0.001). The correlation between BMC of different body composition phenotypes in boys was greater than that in girls. HFMI-HLMI is a risk phenotype negatively associated with Ca content (β = -0.12; 95%CI: -0.19 to -0.04; P < 0.05). Regardless of body composition level, BMC was always negatively correlated with fat mass (LLMI: β = -0.27; 95%CI: -0.32-0.21; HLMI: β = -0.52, 95%CI: -0.65-0.40) and positively correlated with lean mass (LFMI: β =0.24; 95%CI: 0.20-0.28; HFMI: β =0.23, 95%CI:0.13-0.33) (all P < 0.001). The fat mass showed different correlations with OC and CTX in girls and boys based on LLMI or HLMI (all P < 0.05).

CONCLUSION

HFMI-LLMI is a risk phenotype of low BMC in Chinese adolescents, and the relationship between fat mass and bone metabolism markers is affected by lean body mass and gender.

Nutraceuticals and Functional Foods: A Comprehensive Review of Their Role in Bone Health

Bone health is the result of a tightly regulated balance between bone modeling and bone remodeling, and alterations of these processes have been observed in several diseases both in adult and pediatric populations. The imbalance in bone remodeling can ultimately lead to osteoporosis, which is most often associated with aging, but contributing factors can already act during the developmental age, when over a third of bone mass is accumulated. The maintenance of an adequate bone mass is influenced by genetic and environmental factors, such as physical activity and diet, and particularly by an adequate intake of calcium and vitamin D. In addition, it has been claimed that the integration of specific nutraceuticals such as resveratrol, anthocyanins, isoflavones, lycopene, curcumin, lutein, and β-carotene and the intake of bioactive compounds from the diet such as honey, tea, dried plums, blueberry, and olive oil can be efficient strategies for bone loss prevention. Nutraceuticals and functional foods are largely used to provide medical or health benefits, but there is an urge to determine which products have adequate clinical evidence and a strong safety profile. The aim of this review is to explore the scientific and clinical evidence of the positive role of nutraceuticals and functional food in bone health, focusing both on molecular mechanisms and on real-world studies.

Systemic Inflammatory Regulators Associated with Osteoporosis: A Bidirectional Mendelian Randomization Study

To elucidate the precise upstream and downstream regulatory mechanisms of inflammatory factors in osteoporosis (OP) progression and to establish a causal relationship between inflammatory factors and OP. We conducted bidirectional Mendelian randomization (MR) analyses using data for 41 cytokines obtained from three independent cohorts comprising 8293 Finnish individuals. Estimated bone mineral density (eBMD) data were derived from 426,824 UK Biobank White British individuals (55% female) and fracture data from 416,795 UK Biobank participants of European ancestry. The inverse variance-weighted method was the primary MR analysis approach. We employed other methods as complementary approaches for mutual corroboration. To test for pleiotropy and heterogeneity, we used the MR-Egger regression, MR-pleiotropy residual sum and outlier global test, and the Cochrane Q test. Macrophage inflammatory protein (MIP)-1α and interleukin (IL)-12p70 expression associated negatively and causally with eBMD (β = -0.017 [MIP-1α], β = -0.011 [IL-12p70]). Conversely, tumor necrosis factor-related apoptosis-inducing ligand was associated with a decreased risk of fractures (Odds Ratio: 0.980). Additionally, OP influenced the expression of multiple inflammatory factors, including growth-regulated oncogene-α, interferon-gamma, IL-6, beta nerve growth factor, and IL-2. Finally, we discovered complex bidirectional causal relationships between IL-8, IL-10, and OP. Specific inflammatory factors may contribute to OP development or may be causally affected by OP. We identified a bidirectional causal relationship between certain inflammatory factors and OP. These findings provide new perspectives for early prediction and targeted treatment of OP. Larger cohort studies are necessary in the future to further validate these findings.

Predictive factors of bone strength variation in adolescent girls according to body composition

PURPOSE

This study examined correlations among anthropometric parameters, body composition, bone parameters and predictive factors of bone mass in adolescent girls with different body fat percentages (%fat).

METHODS

A total of 129 females aged 15-18 years were categorized into 3 groups using %fat-for-age at the 50th and 95th percentiles as cutoff points (normal, over, and excess %fat groups). We recorded anthropometric data and measured the speed of sound at the tibia and radius using quantitative ultrasound. Dual-energy x-ray absorptiometry (DXA) was used to measure body composition and bone parameters, including bone mineral density (BMD), bone mineral content (BMC), and the BMD-z-score (z-score) in the lumbar spine (LS) and whole body (WB). These parameters were compared among the 3 groups using bivariate and multivariate correlation analyses.

RESULTS

There were strong correlations among all anthropometric parameters, body composition, and DXA in the over %fat group. Lean parameters strongly correlated with LS and WB in the normal %fat group, whereas both lean mass (LM) and fat mass (FM) were positively correlated with BMC in the excess %fat group. The predictive factors of bone mass differed among the groups, as follows: lean body mass was predictive of BMD and BMC at both sites in the normal and over %fat groups; LM and body weight were predictive of LS-BMC and WB-bones, respectively, in the over %fat group; and FM was predictive of WB-bones in the excess %fat group. Body fat and waist circumference were negative predictors of bone mass.

CONCLUSION

Predictive factors of bone strength appear to depend on the amount of body fat in adolescent girls.

Obesity, diabetes and risk of bone fragility: How BMAT behavior is affected by metabolic disturbances and its influence on bone health

PURPOSE

Osteoporosis is a metabolic bone disease characterized by decreased bone strength and mass, which predisposes patients to fractures and is associated with high morbidity and mortality. Like osteoporosis, obesity and diabetes are systemic metabolic diseases associated with modifiable risk factors and lifestyle, and their prevalence is increasing. They are related to decreased quality of life, functional loss and increased mortality, generating high costs for health systems and representing a worldwide public health problem. Growing evidence reinforces the role of bone marrow adipose tissue (BMAT) as an influential factor in the bone microenvironment and systemic metabolism. Given the impact of obesity and diabetes on metabolism and their possible effect on the bone microenvironment, changes in BMAT behavior may explain the risk of developing osteoporosis in the presence of these comorbidities.

METHODS

This study reviewed the scientific literature on the behavior of BMAT in pathological metabolic conditions, such as obesity and diabetes, and its potential involvement in the pathogenesis of bone fragility.

RESULTS

Published data strongly suggest a relationship between increased BMAT adiposity and the risk of bone fragility in the context of obesity and diabetes.

CONCLUSION

By secreting a broad range of factors, BMAT modulates the bone microenvironment and metabolism, ultimately affecting skeletal health. A better understanding of the relationship between BMAT expansion and metabolic disturbances observed in diabetic and obese patients will help to identify regulatory pathways and new targets for the treatment of bone-related diseases, with BMAT as a potential therapeutic target.

Joint modeling of association networks and longitudinal biomarkers: An application to childhood obesity

The prevalence of chronic non-communicable diseases such as obesity has noticeably increased in the last decade. The study of these diseases in early life is of paramount importance in determining their course in adult life and in supporting clinical interventions. Recently, attention has been drawn to approaches that study the alteration of metabolic pathways in obese children. In this work, we propose a novel joint modeling approach for the analysis of growth biomarkers and metabolite associations, to unveil metabolic pathways related to childhood obesity. Within a Bayesian framework, we flexibly model the temporal evolution of growth trajectories and metabolic associations through the specification of a joint nonparametric random effect distribution, with the main goal of clustering subjects, thus identifying risk sub-groups. Growth profiles as well as patterns of metabolic associations determine the clustering structure. Inclusion of risk factors is straightforward through the specification of a regression term. We demonstrate the proposed approach on data from the Growing Up in Singapore Towards healthy Outcomes cohort study, based in Singapore. Posterior inference is obtained via a tailored MCMC algorithm, involving a nonparametric prior with mixed support. Our analysis has identified potential key pathways in obese children that allow for the exploration of possible molecular mechanisms associated with childhood obesity.

Cereal sprout-based food products: Industrial application, novel extraction, consumer acceptance, antioxidant potential, sensory evaluation, and health perspective

Cereal grains are a good source of macronutrients and micronutrients that are required for metabolic activity in the human body. Sprouts have been studied to enhance the nutrient profile. Moreover, secondary metabolites are examined as green food engineering technology that is used in the pharmaceutical, functional ingredients, nutraceutical, and cosmetic industries. The sprout-based food is commonly used to enhance the quality of products by softening the structure of the whole grain and increasing the phytochemicals (nutritional value and bioactive compounds). These sprouting grains can be added to a variety of products including snacks, bakery, beverage, and meat. Consuming whole grains has been shown to reduce the incidence and mortality of a variety of chronic and noncommunicable diseases. Sprouting grains have a diversity of biological functions, including antidiabetic, antioxidant, and anticancer properties. Cereal sprout-based products are more beneficial in reducing the risk of cardiovascular diseases and gastrointestinal tract diseases. The novel extraction techniques (microwave-existed extraction, pulse electric field, and enzyme-associated) are applied to maintain and ensure the efficiency, safety, and nutritional profile of sprout. Nutrient-dense sprouts have a low environmental impact and are widely accepted by consumers. This review explores for the first time and sheds light on the antioxidant potential, sensory evaluation, industrial applications, and health perspective of cereal sprout-based food products.

The relationship between leptin and periodontitis: a literature review

Leptin is a peptide hormone that regulates energy balance, immune inflammatory response, and bone metabolism. Several studies have demonstrated a relationship between leptin and periodontitis, a local inflammatory disease that progressively weakens the supporting structures of the teeth, eventually leading to tooth loss. This article reviews the existing literature and discusses leptin's basic characteristics, its relationship with periodontitis, and its effects on periodontal tissue metabolism.

Musculoskeletal health in children and adolescents

The purpose of this narrative review was to investigate the key determinants of musculoskeletal health in childhood and adolescence, with particular attention to the role of physical activity. First, we examined the importance of bone modeling and remodeling in maintaining the bone health and the integrity and mechanical characteristic of the skeleton. In addition, we reported the evidence on an appropriate calcium and vitamin D intake, as well as local load variation in achieving proper peak bone mass. Proteomic and transcriptomic studies identified the skeletal muscle "secretoma", consisting of several myokines involved in endocrine and paracrine functions. Among these, we explored the role of irisin, a myokine involved in the muscle-bone crosstalk, and in the regulation of metabolic pathways. It is known that physical activity during growing positively impacts on skeleton and can protect by bone loss in adulthood. However, there are still concerns about the optimal interval duration and exercise intensity, particularly at the pubertal growth spurt which represents a window of opportunity to increase skeletal strength. We reported data from clinical trials performed in the last 5 years analyzing the impact of the type and timing of physical activity during childhood on skeletal development. Finally, we reported recent data on the significance of physical activity in some rare diseases.

Body composition phenotypes and bone health in young adults: A cluster analysis

BACKGROUND AND AIMS

Lean mass is considered the best predictor of bone mass, as it is an excellent marker of bone mechanical stimulation, and changes in lean mass are highly correlated with bone outcomes in young adults. The aim of this study was to use cluster analysis to examine phenotype categories of body composition assessed by lean and fat mass in young adults and to assess how these body composition categories are associated with bone health outcomes.

METHODS

Cluster cross-sectional analyses of data from 719 young adults (526 women) aged 18-30 years from Cuenca and Toledo, Spain, were conducted. Lean mass index (lean mass (kg)/height (m)2), fat mass index (fat mass (kg)/height (m)2), bone mineral content (BMC) and areal bone mineral density (aBMD) were assessed by dual-energy X-ray absorptiometry.

RESULTS

A cluster analysis of lean mass and fat mass index z scores resulted in a classification of a five-category cluster solution that could be interpreted according to the body composition phenotypes of individuals as follows: high adiposity-high lean mass (n = 98), average adiposity-high lean mass (n = 113), high adiposity-average lean mass (n = 213), low adiposity-average lean mass (n = 142), and average adiposity-low lean mass (n = 153). ANCOVA models showed that individuals in clusters with a higher lean mass had significantly better bone health (z score: 0.764, se: 0.090) than their peers in other cluster categories (z score: -0.529, se: 0.074) after controlling for sex, age, and cardiorespiratory fitness (p < 0.05). Additionally, subjects belonging to the categories with a similar average lean mass index but with high or low-adiposity levels (z score: 0.289, se: 0.111; z score: 0.086, se: 0.076) showed better bone outcomes when the fat mass index was higher (p < 0.05).

CONCLUSIONS

This study confirms the validity of a body composition model using a cluster analysis to classify young adults according to their lean mass and fat mass indices. In addition, this model reinforces the main role of lean mass on bone health in this population and that in phenotypes with high-average lean mass, factors associated with fat mass may also have a positive effect on bone status.

Bone Remodeling Markers in Children with Acute Lymphoblastic Leukemia after Intensive Chemotherapy: The Screenshot of a Biochemical Signature

PURPOSE

to investigate the effects of intensive chemotherapy and glucocorticoid (GC) treatment on bone remodeling markers in children with acute lymphoblastic leukemia (ALL).

METHODS

A cross-sectional study was carried out in 39 ALL children (aged 7.64 ± 4.47) and 49 controls (aged 8.7 ± 4.7 years). Osteoprotegerin (OPG), receptor activator of NF-κB ligand (RANKL), osteocalcin (OC), C-terminal telopeptide of type I collagen (CTX), bone alkaline phosphatase (bALP), tartrate-resistant acid phosphatase 5b (TRACP5b), procollagen type I N-terminal propeptide (P1NP), Dickkopf-1 (DKK-1), and sclerostin were assessed. Statistical analysis was conducted using the principal component analysis (PCA) to study patterns of associations in bone markers.

RESULTS

ALL patients showed significantly higher OPG, RANKL, OC, CTX, and TRACP5b than the controls (p ≤ 0.02). Considering ALL group, we found a strong positive correlation among OC, TRACP5b, P1NP, CTX, and PTH (r = 0.43-0.69; p < 0.001); between CTX and P1NP (r = 0.5; p = 0.001); and between P1NP and TRAcP (r = 0.63; p < 0.001). The PCA revealed OC, CTX, and P1NP as the main markers explaining the variability of the ALL cohort.

CONCLUSIONS

Children with ALL showed a signature of bone resorption. The assessment of bone biomarkers could help identify ALL individuals who are most at risk of developing bone damage and who need preventive interventions.

The association between abdominal obesity and femoral neck bone mineral density in older adults

BACKGROUND

The relationship between obesity and osteoporosis is complex, with contradictory findings reported. Our aim was to evaluate the association between waist circumference (WC), as an easy-to-determine clinical index of abdominal obesity, and femoral neck bone mineral density (BMD) among older adults, using the National Health and Nutrition Examination Survey (NHANES) database.

METHODS

Data of five NHANES cycles (2005-2010, 2013-2014, and 2017-2018), including 5801 adults aged ≥ 60 years, were used in the analysis. Weighted multiple regression analyses were performed to evaluate the association between WC and femoral neck BMD. Weighted generalized additive models and smooth curve fitting were further performed to characterize nonlinearities in the association.

RESULTS

There was a positive association between WC and femoral neck BMD in non-adjusted models. After adjusting for body mass index (BMI), the association became negative. On subgroup analysis stratified by sex, this negative association only existed for men. An inverted U-shaped curve relationship between WC and femoral neck BMD was further identified, with an inflection point at a WC of 95 cm for both men and women.

CONCLUSIONS

Abdominal obesity is a negative predictor of bone health among older adults, independent of BMI. The association between WC and femoral neck BMD followed an inverted U-shaped curve.

Circulating Extracellular Vesicles Impair Mesenchymal Stromal Cell Differentiation Favoring Adipogenic Rather than Osteogenic Differentiation in Adolescents with Obesity

Excess body weight has been considered beneficial to bone health because of its anabolic effect on bone formation; however, this results in a poor quality bone structure. In this context, we evaluated the involvement of circulating extracellular vesicles in the impairment of the bone phenotype associated with obesity. Circulating extracellular vesicles were collected from the plasma of participants with normal weight, as well as overweight and obese participants, quantified by flow cytometry analysis and used to treat mesenchymal stromal cells and osteoblasts to assess their effect on cell differentiation and activity. Children with obesity had the highest amount of circulating extracellular vesicles compared to controls. The treatment of mesenchymal stromal cells with extracellular vesicles from obese participants led to an adipogenic differentiation in comparison to vesicles from controls. Mature osteoblasts treated with extracellular vesicles from obese participants showed a reduction in differentiation markers in comparison to controls. Children with obesity who regularly performed physical exercise had a lower circulating extracellular vesicle amount in comparison to those with a sedentary lifestyle. This pilot study demonstrates how the high amount of circulating extracellular vesicles in children with obesity affects the bone phenotype and that physical activity can partially rescue this phenotype.

Relationship between body composition and bone mass in normal-weight and overweight adolescents

Adolescence is a period characterized by large accumulation of bone mass. Body composition is an important determinant of bone mass. This study aimed to assess the relationship of bone mass with lean mass (LM) and fat mass (FM) in normal-weight and overweight adolescents with consideration of sex, sexual maturation and physical activity covariates. A total of 118 adolescents (60 girls and 58 boys) aged between 10 and 14 years participated in the study. Individuals were classified as normal weight or overweight according to body mass index. Bone mineral density (BMD), bone mineral content (BMC), LM, and FM were measured by dual-energy X-ray absorptiometry. In normal-weight adolescents, LM (β = 0.725, p < 0.001) and FM (β = 0.185, p = 0.019) were associated with lumbar spine BMC, whereas in overweight adolescents only LM (β = 0.736, p < 0.001) was associated with lumbar spine BMC. Furthermore, in the normal-weight group, FM and LM were associated with total body less head BMD (LM, β = 0.792, p < 0.001; FM, β = 0.257, p = 0.007) and lumbar spine BMD (LM, β = 0.553, p < 0.001; FM, β = 0.199, p < 0.035). In the overweight group, only LM was associated with total body less head BMD (β = 0.682, p < 0.001) and lumbar spine BMD (β = 0.528, p < 0.001). LM was the main predictor of bone mass in normal-weight and overweight adolescents. FM was associated with bone mass in normal-weight adolescents only. LM may be considered an important and useful marker in adolescents, when investigating bone health in this population. Activities that promote LM gain to reduce the risk of bone fractures and diseases in adulthood are recommended.

How high-fat diet affects bone in mice: A systematic review and meta-analysis

High-fat diet (HFD) feeding for mice is commonly used to model obesity. However, conflicting results have been reported on the relationship between HFD and bone mass. In this systematic review and meta-analysis, we synthesized data from 80 articles to determine the alterations in cortical and trabecular bone mass of femur, tibia, and vertebrae in C57BL/6 mice after HFD. Overall, we detected decreased trabecular bone mass as well as deteriorated architecture, in femur and tibia of HFD treated mice. The vertebral trabecula was also impaired, possibly due to its reshaping into a more fragmentized pattern. In addition, pooled cortical thickness declined in femur, tibia, and vertebrae. Combined with changes in other cortical parameters, HFD could lead to a larger femoral bone marrow cavity, and a thinner and more fragile cortex. Moreover, we conducted subgroup analyses to explore the influence of mice's sex and age as well as HFD's ingredients and intervention period. Based on our data, male mice or mice aged 6-12 weeks old are relatively susceptible to HFD. HFD with > 50% of energy from fats and intervention time of 10 weeks to 5 months are more likely to induce skeletal alterations. Altogether, these findings supported HFD as an appropriate model for obesity-associated bone loss and can guide future studies.

The causal impact of childhood obesity on bone mineral density and fracture in adulthood: A two-sample Mendelian randomization study

Observational studies have indicated the associations between obesity with bone mineral density (BMD) and fracture but yield inconsistent results. The impact of childhood obesity on bone health in adulthood is even less clear. The present study adopted the Mendelian randomization methods to determine whether the genetically predicted childhood obesity was causally associated with BMD and the risk of fracture. Genetic variants were extracted from genome-wide association studies (GWAS) to identify childhood obesity loci [IEU open GWAS project: childhood obesity (ID: ieu-a-1096)] and single nucleotide polymorphisms (SNPs) as instrumental variables to investigate causality. We used two-sample univariable Mendelian randomization (MR) to estimate causal relationships between childhood obesity on BMD and fracture subtypes based on SNPs from European samples. To avoid bias, Cochran's Q test and leave-one-out variant analysis were performed. The MR analysis shows strong evidence that childhood obesity is causally associated with eBMD (OR 1.068, 95% CI 1.043–1.095, P &lt; 0.001) and a weak decreased risk of leg fracture (OR 0.9990, 95% CI 0.9981–0.9999, P =0.033) based on the inverse variance weighting (IVW) method. After adjusting for diabetes and adult obesity, the results of eBMD remained the same. The MR analysis revealed sufficient evidence to indicate childhood obesity was causally associated with increased BMD and decreased risk of leg fracture in adults. Childhood obesity could be taken into consideration when assessing eBMD.

The parasitic worm product ES-62 protects the osteoimmunology axis in a mouse model of obesity-accelerated ageing

Despite significant increases in human lifespan over the last century, adoption of high calorie diets (HCD) has driven global increases in type-2 diabetes, obesity and cardiovascular disease, disorders precluding corresponding improvements in healthspan. Reflecting that such conditions are associated with chronic systemic inflammation, evidence is emerging that infection with parasitic helminths might protect against obesity-accelerated ageing, by virtue of their evolution of survival-promoting anti-inflammatory molecules. Indeed, ES-62, an anti-inflammatory secreted product of the filarial nematode Acanthocheilonema viteae, improves the healthspan of both male and female C57BL/6J mice undergoing obesity-accelerated ageing and also extends median lifespan in male animals, by positively impacting on inflammatory, adipose metabolic and gut microbiome parameters of ageing. We therefore explored whether ES-62 affects the osteoimmunology axis that integrates environmental signals, such as diet and the gut microbiome to homeostatically regulate haematopoiesis and training of immune responses, which become dysregulated during (obesity-accelerated) ageing. Of note, we find sexual dimorphisms in the decline in bone health, and associated dysregulation of haematopoiesis and consequent peripheral immune responses, during obesity-accelerated ageing, highlighting the importance of developing sex-specific anti-ageing strategies. Related to this, ES-62 protects trabecular bone structure, maintaining bone marrow (BM) niches that counter the ageing-associated decline in haematopoietic stem cell (HSC) functionality highlighted by a bias towards myeloid lineages, in male but not female, HCD-fed mice. This is evidenced by the ability of ES-62 to suppress the adipocyte and megakaryocyte bias and correspondingly promote increases in B lymphocytes in the BM. Furthermore, the consequent prevention of ageing-associated myeloid/lymphoid skewing is associated with reduced accumulation of inflammatory CD11c+ macrophages and IL-1β in adipose tissue, disrupting the perpetuation of inflammation-driven dysregulation of haematopoiesis during obesity-accelerated ageing in male HCD-fed mice. Finally, we report the ability of small drug-like molecule analogues of ES-62 to mimic some of its key actions, particularly in strongly protecting trabecular bone structure, highlighting the translational potential of these studies.

Plasma proteomics identifies CRTAC1 as a biomarker for osteoarthritis severity and progression

OBJECTIVES

The aim of this study was to identify biomarkers for radiographic OA severity and progression acting within the inflammation and metabolic pathways.

METHODS

For 3517 Rotterdam Study participants, 184 plasma protein levels were measured using Olink inflammation and cardiometabolic panels. We studied associations with severity and progression of knee, hip and hand OA and a composite overall OA burden score by multivariable regression models, adjusting for age, sex, cell counts and BMI.

RESULTS

We found 18 significantly associated proteins for overall OA burden, of which 5 stayed significant after multiple testing correction: circulating cartilage acidic protein 1 (CRTAC1), cartilage oligomeric matrix protein (COMP), thrombospondin 4, IL-18 receptor 1 (IL-18R1) and TNF ligand superfamily member 14. These proteins were also associated with progression of knee OA, with the exception of IL-18R1. The strongest association was found for the level of CRTAC1, with 1 s.d. increase in protein level resulting in an increase of 0.09 (95% CI 0.06, 0.12) in the overall OA Kellgren-Lawrence sum score (P = 2.9 × 10-8) in the model adjusted for age, sex, BMI and cell counts. This association was also present with the severity of OA in all three joints and progression of knee OA and was independent of BMI. We observed a stronger association for CRTAC1 with OA than for the well-known OA biomarker COMP.

CONCLUSION

We identified several compelling biomarkers reflecting the overall OA burden and the increased risk for OA progression. CRTAC1 was the most compelling and robust biomarker for OA severity and progression. Such a biomarker may be used for disease monitoring.

Obesity, Bone Loss, and Periodontitis: The Interlink

Obesity and periodontitis are both common health concerns that have given rise to considerable economic and societal burden worldwide. There are established negative relationships between bone metabolism and obesity, obesity and diabetes mellitus (DM), and DM and periodontitis, to name a few, with osteoporosis being considered a long-term complication of obesity. In the oral cavity, bone metabolic disorders primarily display as increased risks for periodontitis and alveolar bone loss. Obesity-driven alveolar bone loss and mandibular osteoporosis have been observed in animal models without inoculation of periodontopathogens. Clinical reports have also indicated a possible association between obesity and periodontitis. This review systematically summarizes the clinical periodontium changes, including alveolar bone loss in obese individuals. Relevant laboratory-based reports focusing on biological interlinks in obesity-associated bone remodeling via processes like hyperinflammation, immune dysregulation, and microbial dysbiosis, were reviewed. We also discuss the potential mechanism underlying obesity-enhanced alveolar bone loss from both the systemic and periodontal perspectives, focusing on delineating the practical considerations for managing periodontal disease in obese patients.

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

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

Effect of obesity status on adolescent bone mineral density and saturation effect: A cross-sectional study

BACKGROUND

The effect of obesity status on bone mineral density (BMD) in adolescents and whether there is a saturation effect is still insufficient. A cross-sectional study of adolescents aged 12-19 was conducted to investigate them.

METHODS

Weighted multivariate linear regression models were used to assess the relationship between obesity status and BMD via datasets from the National Health and Nutrition Examination Survey 2011-2018. The nonlinear relationships and saturation values were ascertained by fitting smooth curves and analyzing saturation effects. At the same time, the subgroup stratified analysis was also performed.

RESULTS

4056 adolescents were included in this study. We found that body mass index (BMI) and waist circumference (WC) were significantly associated with total BMD, which remained significant in subgroups stratified by age, gender, standing height, and ethnicity. We also noticed an inverse correlation between left leg fat/lean mass and left leg BMD, which was only significant in males and other races. Fitting smooth curve and saturation effect analysis showed that BMI, WC, left leg fat/lean mass, and BMD had a specific saturation effect. There was a saturation effect on bone mineral density in adolescents with a BMI of 22 kg/m², a WC of 70.5 cm, or a left leg fat/lean mass of 0.2994.

CONCLUSIONS

We found a positive saturation effect of BMI and WC with BMD and a negative saturation effect of left leg fat/lean mass with BMD. Appropriate obesity status allows adolescents to have better bone mass development but not excessive obesity.

Role of nitric oxide in type 1 diabetes-induced osteoporosis

Type 1 diabetes (T1D)-induced osteoporosis is characterized by decreased bone mineral density, bone quality, rate of bone healing, bone formation, and increased bone resorption. Patients with T1D have a 2-7-fold higher risk of osteoporotic fracture. The mechanisms leading to increased risk of osteoporotic fracture in T1D include insulin deficiency, hyperglycemia, insulin resistance, lower insulin-like growth factor-1, hyperglycemia-induced oxidative stress, and inflammation. In addition, a higher probability of falling, kidney dysfunction, weakened vision, and neuropathy indirectly increase the risk of osteoporotic fracture in T1D patients. Decreased nitric oxide (NO) bioavailability contributes to the pathophysiology of T1D-induced osteoporotic fracture. This review discusses the role of NO in osteoblast-mediated bone formation and osteoclast-mediated bone resorption in T1D. In addition, the mechanisms involved in reduced NO bioavailability and activity in type 1 diabetic bones as well as NO-based therapy for T1D-induced osteoporosis are summarized. Available data indicates that lower NO bioavailability in diabetic bones is due to disruption of phosphatidylinositol 3‑kinase/protein kinase B/endothelial NO synthases and NO/cyclic guanosine monophosphate/protein kinase G signaling pathways. Thus, NO bioavailability may be boosted directly or indirectly by NO donors. As NO donors with NO-like effects in the bone, inorganic nitrate and nitrite can potentially be used as novel therapeutic agents for T1D-induced osteoporosis. Inorganic nitrites and nitrates can decrease the risk for osteoporotic fracture probably directly by decreasing osteoclast activity, decreasing fat accumulation in the marrow cavity, increasing osteoblast activity, and increasing bone perfusion or indirectly, by improving hyperglycemia, insulin resistance, and reducing body weight.

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.

The Effect of Moderate-Intensity Treadmill Exercise on Bone Mass and the Transcription of Peripheral Blood Mononuclear Cells in Ovariectomized Rats

Objective: Using RNA-sequencing technology to screen the effect of moderate-intensity treadmill exercise on the sensitive genes that affect bone mass in the peripheral blood mononuclear cells (PBMCs) of ovariectomized (OVX) rats.

Methods: Three-month-old female Sprague-Dawley rats of Specific Pathogen Free (SPF) grade were randomly divided into the sham operation (SHAM) group, OVX group, and OVX combined exercise (OVX + EX) group. The OVX + EX group performed moderate-intensity treadmill exercise for 17 weeks. Then, the body composition and bone mineral density (BMD) were measured, and the bone microstructure of the femur was observed. PBMCs were collected from the abdominal aorta, and the differential genes were analyzed by transcriptome sequencing to further screen sensitive genes.

Results: (1) In the OVX group, the body weight and body fat content were significantly higher than in the SHAM group while the muscle content and BMD were significantly lower than the SHAM group. (2) The trabecular bone parameters in the OVX group were significantly lower than in the SHAM group, and they were significantly higher in the OVX + EX group than in the OVX group. When compared with the SHAM group, the microstructure of the distal femur trabecular in the OVX group was severely damaged, suggest that the morphological structure of trabecular bone is severely damaged, the number of trabecular bones is reduced, and the thickness becomes thinner, which lead to the widening of the trabecular bone space and the appearance of osteoporosis. The number and continuity of the trabecular bones were higher in the OVX + EX group than in the OVX group. (3) A Venn diagram showed that there were 58 common differential genes, and the differential genes were mainly enriched in the PI3K-Akt signaling pathway. Five sensitive genes were screened including CCL2, Nos3, Tgfb3, ITGb4, and LpL. The expression of CCL2, Nos3, and Tgfb3 genes was closely related to multiple bone parameters.

Conclusion: Moderate-intensity treadmill exercise may improve the body composition and bone mass of the OVX group by upregulating CCL2 and other genes of the PBMC. The PBMCs in the peripheral blood can be a useful tool for monitoring the effect of exercise on bone health in postmenopausal osteoporosis.

Time trends of overweight and obesity among schoolchildren in Kuwait over a 13-year period (2007-2019): repeated cross-sectional study

OBJECTIVES

This study aimed to examine age-specific trends in the prevalence of overweight and obesity in schoolchildren in Kuwait over a 13-year period (2007 to 2019) using the WHO, the Centers for Disease Control and Prevention (CDC) and the International Obesity Taskforce (IOTF) definitions.

DESIGN

Using cross-sectional approach, Kuwait Nutrition Surveillance System (KNSS) objectively measured weight and height of schoolchildren over a 13-year period. Log-binomial regression models were used to examine age-specific trends of obesity and overweight over the study period.

SETTING

Public primary, middle and high schools in all provinces of Kuwait.

PARTICIPANTS

Schoolchildren aged 5-19 years (n 172 603).

RESULTS

According to the WHO definition, the prevalence of overweight and obesity in schoolchildren, respectively, increased from 17·73 % and 21·37 % in 2007 to 20·19 % and 28·39 % in 2019 (Pfor trend < 0·001). There is evidence that the obesity in females (but not males) has levelled off in the period 2014-2019 according to the three definitions of obesity, which is corroborated by a similar trend in the mean of BMI-for-age Z-score.

CONCLUSION

The prevalence of obesity and overweight in schoolchildren in Kuwait has risen over the last 13 years and trends are similar across all definitions. Obesity is no longer increasing at the same pace and there is evidence that the prevalence of obesity in females has plateaued. The current level of childhood overweight and obesity is too high and requires community-based and school-based interventions.

Sex differences in the relationship between body composition and biomarkers of bone and fat metabolism in obese boys and girls

Whether a body mass derived from extremes of body weight is beneficial to bone remains controversial. When fat accumulation reaches excessive levels and induces changes in hormonal factors and adipokines, it may affect bone accrual during growth. This study evaluated the relationships between body composition and key biomarkers in relation to bone and fat metabolism in obese Thai boys and girls. Subjects aged 12-14 years were grouped by body mass index (BMI) and percentage of body fat (%Fat). Body composition and heel bone Z-score and speed of sound (SOS) were assessed by bioelectrical impedance analysis and calcaneus bone densitometry, respectively. Serum osteocalcin (OC), adiponectin, leptin, insulin, and 25 hydroxyvitamin D (25(OH)D) were measured by ELISA. Their correlations were analyzed and compared between sexes. The results showed that the obese groups had no differences in mean BMIs and body composition, except that boys had more muscle mass than girls. Boys had lower serum OC and leptin levels than girls. Positive correlations of leptin with %Fat and FM were found in both sexes, while positive associations of %Fat with OC and insulin were found only in boys. Bone Z-score and SOS positively correlated with OC in boys but negatively correlated with 25(OH)D in girls. When classifying the obese group using %Fat ≥25, the positive correlations between %Fat and insulin and the negative associations between %Fat and adiponectin in girls were more pronounced. These results suggest that the associations of body fat and bone parameters with OC, adiponectin, 25(OH)D, and insulin were sex-specific, with greater clarity when %Fat was used instead of BMI to classify obesity.

Childhood adiposity, adult adiposity, and bone health

IMPORTANCE

Childhood and adolescence are critical periods for lifelong bone mineral accrual, but few studies have determined the impact of childhood adiposity on adult bone density.

OBJECTIVE

To determine the long-term impact of childhood adiposity on adult areal bone mineral density (aBMD) and the effect of adult adiposity on this relationship.

METHODS

We conducted a longitudinal study of 1156 adults (56.3% men), for whom skinfold thickness (SFT) had been measured during childhood (6-18 years) and fat mass percentage (FMP) and aBMD were measured during adulthood (29-43 years). Adult aBMD in the lumbar spine (LS), femoral neck (FN), arms, and legs was measured using dual-energy X-ray absorptiometry. The direct effect of childhood SFT and its indirect effect through adult FMP on adult aBMD were estimated using general linear regression and a causal steps approach.

RESULTS

Significant positive associations between childhood SFT and adult aBMD were found in the LS in men (β = 0.089, P = 0.044) and in all the skeletal sites in women. With respect to the adult fat-bone relationship, high adult FMP was associated with low aBMD in most of the sites in men, but with high FN aBMD in women (β = 0.144, P = 0.002). Moreover, suppressive effects of adult FMP on the associations between childhood SFT and adult aBMD in the LS (-34.8%) and legs (-67.1%) of men, and a positive effect on the FN aBMD in women (17.0%) were identified.

INTERPRETATION

Childhood adiposity appears to have a positive long-term effect on adult aBMD, which may be reduced by adiposity in adult men but reinforced by adiposity in adult women.

Regulation of Osteoclast Differentiation and Activity by Lipid Metabolism

Bone is a dynamic tissue and is constantly being remodeled by bone cells. Metabolic reprogramming plays a critical role in the activation of these bone cells and skeletal metabolism, which fulfills the energy demand for bone remodeling. Among various metabolic pathways, the importance of lipid metabolism in bone cells has long been appreciated. More recent studies also establish the link between bone loss and lipid-altering conditions—such as atherosclerotic vascular disease, hyperlipidemia, and obesity—and uncover the detrimental effect of fat accumulation on skeletal homeostasis and increased risk of fracture. Targeting lipid metabolism with statin, a lipid-lowering drug, has been shown to improve bone density and quality in metabolic bone diseases. However, the molecular mechanisms of lipid-mediated regulation in osteoclasts are not completely understood. Thus, a better understanding of lipid metabolism in osteoclasts can be used to harness bone cell activity to treat pathological bone disorders. This review summarizes the recent developments of the contribution of lipid metabolism to the function and phenotype of osteoclasts.

Age-dependent changes in pediatric scaphoid fracture pattern on radiographs

OBJECTIVE

To systematically investigate age-dependent changes in scaphoid fracture prevalence and fracture patterns on radiographs in children under 15 years of age.

METHODS AND MATERIALS

This retrospective study included children with scaphoid fractures, who underwent radiographic examinations between May 1, 2009, and August 31, 2019. Blinded to outcome, all radiographs were reviewed to determine fracture visibility on initial radiographs; to characterize fracture location (distal corner, distal, mid, and proximal body) and orientation (horizontal oblique, transverse, and vertical oblique); and to identify the presence or absence of gap, displacement, and concomitant fractures. Demographic information and information on weight and height were collected. Mann-Whitney U, Kruskal-Wallis rank sum, chi-square, and post hoc tests were used to investigate associations between age, fracture characteristics, and BMI percentile.

RESULTS

The study included 180 children (134 boys and 46 girls; 12.3 ± 1.4 years) with 59 (33%) distal corner, 42 (23%) distal, 76 (42%) mid, and 3 (2%) proximal body fractures. Younger children were more likely to present with distal corner and distal body fractures while older children with mid and proximal body fractures (p = 0.035). No association was found between age and fracture visibility (p = 0.246), fracture orientation (p = 0.752), presence of gap (p = 0.130), displacement (p = 0.403), or concomitant fractures (p = 0.588). Younger children with scaphoid fractures were more likely to be obese (n = 117; p = 0.038).

CONCLUSION

Scaphoid fractures of the distal corner and distal body were significantly more common in younger children, who are more likely to be obese.

Monitoring and maintaining bone health in patients with Turner syndrome

INTRODUCTION

Subjects affected with Turner Syndrome (TS) suffer low bone mineral density and high risk of fracture from a young age. Estrogen deficiency is considered the main risk factor but other factors, such as intrinsic bone abnormalities, enhanced osteoclastogenesis, vitamin D deficiency and other comorbidities may contribute to the exalted bone fragility.

AREAS COVERED

The authors performed a literature search in PubMed and EMBASE, using selected key words. They focused their search on pathogenetic mechanisms of osteoporosis in TS and updated the diagnosis, prevention and therapeutic interventions.

EXPERT OPINION

Bone health is a concern in subjects with TS, and strategies to prevent osteoporosis and fractures should be considered from childhood. Advice on how to live a healthy lifestyle, including physical activity and correct nutrition, should be given during childhood in order to prevent bone impairment later in life. The screening for vitamin D deficiency should be performed between the ages of 9 and 11, and every 2-3 years thereafter. Early initiation of estrogen replacement therapy (ERT) between 11-12 years of age, prompt titration to the adult dose after 2 years, and long-term follow-up to guarantee compliance with ERT, are the key points of osteoporosis prevention in women with TS.

Obesity and Bone

Obesity and osteoporosis are both common conditions with high rates of morbidity and mortality. There is a relationship between obesity and bone. There are multiple factors that influence the risk of fracture, including the quality of bone, the risk of falls, and the padding around the bone. These multiple factors partly explain the finding that obesity protects against fractures in some sites while increasing the risk in other parts of the body. While it is well known that increased weight builds bone, there are several mechanisms related to the obese state that make the bone more fragile. These include the increased production of bone marrow fat cells at the expense of bone-forming osteoblasts, an increase in inflammatory cytokines leading to the activation of bone-resorbing osteoclasts, mutations in the FTO gene, and obesity-induced increased osteoblast senescence. Surprisingly, the relationship between bone and obesity is not unidirectional; there is now evidence that osteocytes are able to regulate body weight by acting as weighing machines.

Light and Low Relative Humidity Increase Antioxidants Content in Mung Bean (Vigna radiata L.) Sprouts

In the last decades, there has been a growing interest in the production of sprouts, since they are a highly nutritious food, particularly suitable for indoor farming in urban areas. Achieving sprout production in indoor systems requires an understanding of possible alterations induced by the microclimate. The aim of this study was to analyze the combined effect of presence/absence of light and high/low air relative humidity (RH) on mung bean sprouts. Morpho-anatomical development and functional anatomical traits in hypocotyl were quantified. The content of antioxidants, soluble sugars, and starch were measured for nutritional and functional purposes. Different RH regimes mainly induced morpho-anatomical modifications, while the presence/absence of light changed the content of antioxidant compounds. Increments in stele diameter at high RH suggest a higher water uptake and conductivity, compared to the low RH treatment; low RH and light induced anatomical traits improving plant water transport (reduced number of cortical layers) and increased the production of antioxidants. The overall results suggested that RH and light, already at the early stages of development, affect the plant's nutritional value. Therefore, the combination of light and low RH allows the production of antioxidant-rich mung bean sprouts to be used as a food supplement.

Activation of SIRT1 promotes cartilage differentiation and reduces apoptosis of nucleus pulposus mesenchymal stem cells via the MCP1/CCR2 axis in subjects with intervertebral disc degeneration

Intervertebral disc degeneration (IDD) is a condition involving disruption of the bone tissue distribution. Nucleus pulposus mesenchymal stem cells (NPMSCs) and Sirtuin 1 (SIRT1) play important roles in bone diseases, therefore the aim of the present study was to evaluate the roles of SIRT1 and NPMSCs in IDD. First, NPMSCs were harvested from patients with IDD. Then, the NPMSCs were treated with a SIRT activator, and monocyte chemoattractant protein 1 (MCP1) and chemokine receptor 2 (CCR2) inhibitors. Indices related to NPMSC growth, proliferation, differentiation and apoptosis were measured. Subsequently, IDD rat models were established and were transfected with NPMSCs overexpressing SIRT1. NPMSC apoptosis and cartilage differentiation were detected in the rat IDD model. SIRT1 expression was found to be decreased, and the expression of MCP1 and CCR2 increased in NPMSCs of patients with IDD. The upregulation of SIRT1 and the downregulation of the MCP1/CCR2 axis promoted cartilage differentiation and reduced the number of apoptotic NPMSCs. Furthermore, MCP1 reversed the progression of the cartilage differentiation of NPMSCs and the inhibition of NPMSC apoptosis induced by SIRT1 overexpression. Moreover, the transplantation of rat NPMSCs overexpressing SIRT1 relieved IDD in rats. Therefore, SIRT1 overexpression improved cartilage differentiation and reduced the apoptosis of NPMSCs by inactivating the MCP1/CCR2 axis, thus attenuating IDD in rats.

Shedding "LIGHT" on the Link between Bone and Fat in Obese Children and Adolescents

Obesity may affect bone health, but literature reports are contradictory about the correlation of body mass index (BMI) and bone markers. LIGHT, one of the immunostimulatory cytokines regulating the homeostasis of bone and adipose tissue, could be involved in obesity. The study involved 111 obese subjects (12.21 ± 3.71 years) and 45 controls. Patients underwent the evaluation of bone status by quantitative ultrasonography (QUS). LIGHT amounts were evaluated in sera by ELISA, whereas its expression on peripheral blood cells was evaluated by flow cytometry. Osteoclastogenesis was performed by culturing peripheral blood mononuclear cells (PBMCs) with or without anti-LIGHT antibodies. Obese patients showed significant high BMI-standard deviation score (SDS), weight-SDS, and Homeostatic model assessment for insulin resistance (HOMA-IR) that negatively correlated with the reduced Amplitude Dependent Speed of Sound (AD-SoS)-Z-score and Bone Transmission Time (BTT-Z)-score. They displayed significantly higher serum levels of LIGHT compared with controls (497.30 ± 363.45 pg/mL vs. 186.06 ± 101.41 pg/mL, p < 0.001). LIGHT expression on monocytes, CD3+-T-cells, and neutrophils was also higher in obese patients than in the controls. Finally, in PBMC cultures, the addition of anti-LIGHT antibodies induced a significant osteoclastogenesis inhibition. Our study highlighted the high serum levels of LIGHT in obese children and adolescents, and its relationship with both the grade of obesity and bone impairment.

Novel insights in health-promoting properties of sweet cherries

Sweet cherry (Prunus avium L.) is one of the most popular and appreciated temperate fruit not only for its sensory and nutritional properties, but also for its content in bioactive compounds. Consumption of sweet cherries brings beneficial effects on to health, which include prevention and modulatory effects in several chronic diseases such as (diabetes mellitus, cancer, cardiovascular and other inflammatory diseases). The presence of natural polyphenolic compounds with high antioxidant potential might drive and partly explain such beneficial effects, but more translational and clinical studies should address this topic. Here, we review the health-promoting properties of cherries and their bioactive compounds against human diseases.

Polyphenols and obesity prevention: critical insights on molecular regulation, bioavailability and dose in preclinical and clinical settings

Obesity represents one of the most important public health challenges of the 21st century and is characterized by a multifactorial etiology in which environmental, behavioral, metabolic, and genetic factors work together. Despite the rapid increase in prevalence of obesity in the last decades, especially in children, it remains a preventable disease. To battle obesity a multisector approach promoting healthier lifestyle in terms of physical activity and nutrition is needed. Specifically, biologically active dietary compounds, as polyphenols, are able to modulate the expression of genes involved in the development and progression of obesity and its comorbidities as demonstrated by multiple studies using different obesity models. However, human studies focusing on the transcriptomic modulation by polyphenols in obese patients are still limited and do not often recapitulate the results obtained in preclinical setting likely due to the underestimation of some variables such as bioavailability, dose and form (native vs. metabolized) of polyphenols used. The aim of this review is to summarize the state-of-art of nutrigenomic in vitro, in vivo and ex vivo studies as well as clinical trials based on dietary polyphenols to fight obesity. We also critical discuss the variables to be considered to fill the gap between preclinical and clinical settings.

Leptin signaling and the intervertebral disc: Sex dependent effects of leptin receptor deficiency and Western diet on the spine in a type 2 diabetes mouse model

Type 2 diabetes and obesity are associated with back pain in juveniles and adults and are implicated in intervertebral disc (IVD) degeneration. Hypercaloric Western diets are associated with both obesity and type 2 diabetes. The objective of this study was to determine if obesity and type 2 diabetes result in spinal pathology in a sex-specific manner using in vivo diabetic and dietary mouse models. Leptin is an appetite-regulating hormone, and its deficiency leads to polyphagia, resulting in obesity and diabetes. Leptin is also associated with IVD degeneration, and increased expression of its receptor was identified in degenerated IVDs. We used young, leptin receptor deficient (Db/Db) mice to mimic the effect of diet and diabetes on adolescents. Db/Db and Control mice were fed either Western or Control diets, and were sacrificed at 3 months of age. Db/Db mice were obese, while only female mice developed diabetes. Female Db/Db mice displayed altered IVD morphology, with increased intradiscal notochordal band area, suggesting delayed IVD cell proliferation and differentiation, rather than IVD degeneration. Motion segments from Db/Db mice exhibited increased failure risk with decreased torsional failure strength. Db/Db mice also had inferior bone quality, which was most prominent in females. We conclude that obesity and diabetes due to impaired leptin signaling contribute to pathological changes in vertebrae, as well as an immature IVD phenotype, particularly of females, suggesting a sex-dependent role of leptin in the spine.

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.

The Bones of Children With Obesity

Excess adiposity in childhood may affect bone development, ultimately leading to bone frailty. Previous reports showing an increased rate of extremity fractures in children with obesity support this fear. On the other hand, there is also evidence suggesting that bone mineral content is higher in obese children than in normal weight peers. Both adipocytes and osteoblasts derive from multipotent mesenchymal stem cells (MSCs) and obesity drives the differentiation of MSCs toward adipocytes at the expense of osteoblast differentiation. Furthermore, adipocytes in bone marrow microenvironment release a number of pro-inflammatory and immunomodulatory molecules that up-regulate formation and activation of osteoclasts, thus favoring bone frailty. On the other hand, body adiposity represents a mechanical load, which is beneficial for bone accrual. In this frame, bone quality, and structure result from the balance of inflammatory and mechanical stimuli. Diet, physical activity and the hormonal milieu at puberty play a pivotal role on this balance. In this review, we will address the question whether the bone of obese children and adolescents is unhealthy in comparison with normal-weight peers and discuss mechanisms underlying the differences in bone quality and structure. We anticipate that many biases and confounders affect the clinical studies conducted so far and preclude us from achieving robust conclusions. Sample-size, lack of adequate controls, heterogeneity of study designs are the major drawbacks of the existing reports. Due to the increased body size of children with obesity, dual energy absorptiometry might overestimate bone mineral density in these individuals. Magnetic resonance imaging, peripheral quantitative CT (pQCT) scanning and high-resolution pQCT are promising techniques for the accurate estimate of bone mineral content in obese children. Moreover, no longitudinal study on the risk of incident osteoporosis in early adulthood of children and adolescents with obesity is available. Finally, we will address emerging dietary issues (i.e., the likely benefits for the bone health of polyunsaturated fatty acids and polyphenols) since an healthy diet (i.e., the Mediterranean diet) with balanced intake of certain nutrients associated with physical activity remain the cornerstones for achieving an adequate bone accrual in young individuals regardless of their adiposity degree.