Interrelationship among muscle, fat, and bone: connecting the dots on cellular, hormonal, and whole body levels

Is There Enough Evidence for Osteosarcopenic Obesity as a Distinct Entity? A Critical Literature Review

The co-existence of impaired bone health (osteopenia/osteoporosis), reduced muscle mass and strength (sarcopenia), and increased adiposity (obesity) in middle-aged and older people has been identified in recent studies, leading to a proposal for the existence of "osteosarcopenic obesity" as a distinct entity. Evidence for the pathophysiological overlap of these conditions is mounting, although a causal relationship is yet to be established. Each component condition occurs frequently with increasing age, and with shared risk factors in many instances, thus, an overlap of these three conditions is not surprising. However, whether the concurrent existence of sarcopenia, osteoporosis and obesity leads to an increased risk of adverse musculoskeletal outcomes and mortality above and beyond the risks associated with the sum of the component parts remains to be proven and is a question of research interest. In this article, we review evidence for the existence of osteosarcopenic obesity including the current operational definition of osteosarcopenic obesity, prevalence, pathophysiology, outcomes and exploratory approaches to the management of components. We conclude that, there is insufficient evidence to support a discrete clinical entity of osteosarcopenic obesity at this time. To expand knowledge and understanding in this area, there is a need for consensus on a definition of osteosarcopenic obesity which will allow for identification, further epidemiological studies and comparisons between studies. Additionally, studies should assess whether the clinical outcomes associated with osteosarcopenic obesity are worse than the mere addition of those linked with its components. This will help to determine whether defining a person as having this triad will eventually result in a more effective treatment than addressing each of the three conditions separately.

Association between osteosarcopenic obesity and hypertension among four minority populations in China: a cross-sectional study

OBJECTIVE

Osteosarcopenic obesity (OSO) may be associated with an increased prevalence of hypertension. The aim of this study was to examine the difference in the prevalence of OSO and hypertension among four minority populations in China and explore the relationship between OSO and hypertension by sex.

DESIGN

This study adopted a cross-sectional design.

PARTICIPANTS

In total, 1939 participants aged ≥50 years, including 459 Jing, 514 Maonan, 535 Hmong and 431 Yao participants from Guangxi Province, China, were included using stratified cluster random sampling.

MAIN OUTCOME MEASURES

The body composition, bone mineral density and blood pressure were measured by an MC-180 body composition analyser, Achilles Express ultrasound bone densitometer and OMRON HEM-1000 electronic sphygmomanometer, respectively.

RESULTS

The results showed that 65.77% of Hmong men, 58.79% of Hmong women, 54.82% of Maonan men, 50.00% of Maonan women, 41.92% of Jing men, 45.21% of Jing women, 53.66% of Yao men and 42.32% of Yao women suffered from hypertension. Compared with those among the normal group, the adjusted OR and 95% CI of age among the women with OSO was 3.15 (1.13 to 8.78). After adjusting for age, ethnicity, smoking status, alcohol consumption, physical activity and menopausal status, the women with OSO also had a higher OR (OR=3.18, 95% CI 1.14 to 8.88) for hypertension than those in the normal group. However, the ORs (95% CI) for hypertension in men with one or more components were not significant after adjusting for age and ethnicity.

CONCLUSION

These results suggest that OSO is a risk factor for hypertension, especially in women. Furthermore, the prevalence of OSO and hypertension in the present study displayed sex-specific and ethnic-specific differences among the four minority populations.

Gut Microbiota, Muscle Mass and Function in Aging: A Focus on Physical Frailty and Sarcopenia

Human gut microbiota is able to influence the host physiology by regulating multiple processes, including nutrient absorption, inflammation, oxidative stress, immune function, and anabolic balance. Aging is associated with reduced microbiota biodiversity, increased inter-individual variability, and over-representation of pathobionts, and these phenomena may have great relevance for skeletal muscle mass and function. For this reason, the presence of a gut-muscle axis regulating the onset and progression of age-related physical frailty and sarcopenia has been recently hypothesized. In this narrative review, we summarize the studies supporting a possible association between gut microbiota-related parameters with measures of muscle mass, muscle function, and physical performance in animal models and humans. Reduced muscle mass has been associated with distinct microbiota composition and reduced fermentative capacity in mice, and the administration of probiotics or butyrate to mouse models of muscle wasting has been associated with improved muscle mass. However, no studies have targeted the human microbiome associated with sarcopenia. Limited evidence from human studies shows an association between microbiota composition, involving key taxa such as Faecalibacterium and Bifidobacterium, and grip strength. Similarly, few studies conducted on patients with parkinsonism showed a trend towards a different microbiota composition in those with reduced gait speed. No studies have assessed the association of fecal microbiota with other measures of physical performance. However, several studies, mainly with a cross-sectional design, suggest an association between microbiota composition and frailty, mostly assessed according to the deficit accumulation model. Namely, frailty was associated with reduced microbiota biodiversity, and lower representation of butyrate-producing bacteria. Therefore, we conclude that the causal link between microbiota and physical fitness is still uncertain due to the lack of targeted studies and the influence of a large number of covariates, including diet, exercise, multimorbidity, and polypharmacy, on both microbiota composition and physical function in older age. However, the relationship between gut microbiota and physical function remains a very promising area of research for the future.

Age- and sex-specific reference intervals for visceral fat mass in adults

BACKGROUND/OBJECTIVES

Dual-energy X-ray absorptiometry (DXA) is becoming a method of choice for the assessment of visceral adipose tissue (VAT) but the lack of robust reference ranges presents a challenge to the interpretation of VAT in clinical practice, research settings, and the athletic environment. The objective of this study was to develop age- and sex-specific reference intervals for DXA-derived VAT mass.

SUBJECTS/METHODS

The reference group comprised 3219 adults (1886 general population, 42% women; 1333 athletes, 11% women) in the United Kingdom, aged 18-83 years. Total body scans were performed using a GE Lunar iDXA and VAT analyses were enabled through Corescan software (Encore version 15.0). Age-specific reference ranges were derived in samples stratified by sex and general population/ athlete status. We modelled the mean and SD of Box-Cox transformed VAT mass as a function of age with a generalised least squares method using fractional polynomials (Stata® -xrigls- program). Centile values were then back-transformed to provide reference intervals on the original scale.

RESULTS

In general population samples, average VAT mass increases with age up until around 65-70 years, and then begins to decline at older ages, though data are relatively sparse at the upper end of the age range. In athletes, on average, VAT mass increases with advancing age in men and women. Both 95 and 98% reference ranges are presented in 5-year increments in all samples, and we provide equations to enable the calculation of any centile, for any age within the range.

CONCLUSIONS

These reference data can aid the interpretation of VAT mass specific to an individual's sex, age, and athletic status, increasing the utility and applicability of DXA-derived VAT assessments. Additional research is needed in adults over 65 years and female athletes, with different DXA devices, across different ethnic groups and specific sports.

Role of Calcium and Low-Fat Dairy Foods in Weight-Loss Outcomes Revisited: Results from the Randomized Trial of Effects on Bone and Body Composition in Overweight/Obese Postmenopausal Women

Several studies have investigated the possibility of dairy foods and calcium (Ca) mediating weight and body composition, but a consensus has not been reached. We aimed to investigate weight-loss-related outcomes during intervention with low-fat dairy foods or Ca + vitamin D supplements, both as complements to hypocaloric diets. Overweight/obese Caucasian, early-postmenopausal women (n = 135) were recruited for a 6 month energy-restricted weight loss study complemented with either low-fat dairy foods (D; 4–5 servings/day), or Ca + vitamin D supplements (S); both to amount a total of ~1500 mg/day and 600 IU/day of Ca and vitamin D, respectively, or placebo pills (C). Bone mineral density (BMD) and lean and fat tissue were measured by Lunar iDXA. Serum and urinary markers of bone turnover were analyzed. Diet and physical activity were assessed with 3-day records. Participants on average lost ~4%, ~3%, and ~2% of body weight, fat, and lean tissue, respectively. The significantly better outcomes were noticed in participants in the D group regarding body composition (fat loss/lean tissue preservation) and in participants in the S group regarding the BMD outcomes, compared to those in the C group. Therefore, increasing low-fat dairy foods to 4–5 servings/day and/or increasing Ca & vitamin D intake by supplements (in those who are at the borderline dietary intake) may be beneficial for weight loss/maintenance and may lead to more favorable bone and body composition outcomes in postmenopausal women during moderate weight loss.

Association of body composition with predicted hip bone strength among Chinese postmenopausal women: a longitudinal study

Body composition and bone strength are closely associated. How lean mass (LM) and fat mass (FM) contribute to bone strength remains ambiguous. We investigated the associations of total body LM and FM with changes in predicted hip bone strength over a period of 3 years in 1,743 postmenopausal Chinese women from the communities of Guangzhou, China. The body compositions of the women were obtained with dual-energy X-ray absorptiometry. We used the hip structure analysis program to obtain the bone parameters at the femoral neck region, including the bone mineral density (BMD), cross-sectional area (CSA), cortical thickness (CT), section modulus (SM) and buckling ratio (BR). We found the FM and LM were positive predictors for hip bone strength (β > 0, P < 0.05). The LM had a larger contribution to the BMD, CSA, CT, SM and/or their annual percent changes (βLM > βFM), while the contribution of FM to the BR and its annual percent change was higher than LM (|βFM| > |βLM|). Further analysis found that the associations of FM and LM with bone parameters were stronger in the underweight and normal weight participants (|βBMI1| > |βBMI2|). Overall, FM and LM had positive but differential effects on predicted hip bone strength, with a higher impact in the thinner participants.

Osteosarcopenic Obesity: Current Knowledge, Revised Identification Criteria and Treatment Principles

Osteosarcopenic obesity (OSO) syndrome describes the simultaneous deterioration of bone, muscle and excess fat, resulting in reduced functionality and systemic metabolic dysregulation. The key component contributing to this may be ectopic fat in the viscera, bone and muscle. OSO research to date is summarized, and the revised criteria for its identification for research purposes are reviewed and proposed, including new criteria to assess visceral fat in males and females. Finally, nutritional and physical activity recommendations are consolidated into a treatment algorithm, which can be validated in future studies and which may also be applied to preventative management.

Muscle mass measures and incident osteoporosis in a large cohort of postmenopausal women

BACKGROUND

Despite several muscle mass measures being used in the current definitions of sarcopenia, their usefulness is uncertain because of limited data on their association with health outcomes. The aim of the study was to compare the performance of different muscle mass measures for predicting incident osteoporosis in postmenopausal women.

METHODS

This study included data from 149 166 participants (aged 60.3 ± 5.5 years) as part of the UK Biobank cohort. Body composition was assessed using bioelectrical impedance. The muscle mass measures included were total body skeletal muscle mass (SMM) and appendicular SMM (aSMM) divided by height squared (ht² ), derived residuals, SMM, SMM adjusted for body mass (SMM/bm × 100), and aSMM normalized for body mass index (aSMM/BMI). Diagnoses of the events were confirmed by primary care physicians and coded according to the World Health Organization's International Classification of Diseases 10th Revision (ICD-10: M80-M82).

RESULTS

Over a median follow-up of 6.75 (5th to 95th percentile interval, 1.53 to 8.37) years, 394 newly diagnosed cases of osteoporosis occurred, with 40 (10.2%) cases being associated with a pathological fracture. SMM/ht² , aSMM/ht² residual, and SMM were lower in postmenopausal women with osteoporosis compared with women without (all P < 0.0001), while SMM/bm × 100 (P = 0.003), but not aSMM/BMI (P = 0.59), was higher in the osteoporosis group. The unadjusted rates of osteoporosis increased with decreasing quintiles for SMM/ht² , aSMM/ht² , residuals, and SMM (all P trend <0.0001), while the incidence of osteoporosis increased with increasing SMM/bm × 100 (P trend =0.001), but not for aSMM/BMI (P = 0.45). After minimally adjusting for age and after full adjustment, SMM/ht² , aSMM/ht² , and SMM were the only measure that consistently predicted osteoporosis in the total group of postmenopausal women [hazard ratio (HR) 0.65-0.67, all P ≤ 0.0001], in lean women (HR 0.62-0.68; all P ≤ 0.001), and women with increased adiposity (HR 0.64-0.68; all P ≤ 0.01). In fully adjusted models, the changes in the R² statistic were 13.4%, 11.6%, and 15.3% for the SMM/ht² (aSMM/ht² ), residual, and SMM, but only 4.9% and 1.3% for SMM/bm × 100 and aSMM/BMI.

CONCLUSIONS

Muscle mass measures adjusted for height only (SMM/ht² , aSMM/ht² ) appear to be better muscle-relevant risk factors for incident osteoporosis in postmenopausal women, including when stratified into lean participants and participants with increased adiposity.

Utilizing Dietary Nutrient Ratios in Nutritional Research: Expanding the Concept of Nutrient Ratios to Macronutrients

We recently showed that using micronutrient ratios in nutritional research might provide more insights into how diet affects metabolism and health outcomes, based on the notion that nutrients, unlike drugs, are not consumed one at a time and do not target a single metabolic pathway. In this paper, we present a concept of macronutrient ratios, including intra- and inter-macronutrient ratios. Macronutrient intakes from food only, from the What We Eat in America website (summarized National Health and Nutrition Examination Survey data) were transposed into Microsoft Excel to generate ratios. Overall, the dietary ratios of macronutrients may be more revealing and useful in epidemiology and in basic nutritional research than focusing on individual protein, fat, and carbohydrate intakes. While macronutrient ratios may be applied to all types of nutritional research, nutritional epidemiology, and, ultimately, dietary guidelines, the methodology required has not been established yet. In the meantime, intra- and inter-macronutrient ratios may serve as a measure of individual and total macronutrient quality.

Relative Strength, but Not Absolute Muscle Strength, Is Higher in Exercising Compared to Non-Exercising Older Women

Exercise has been suggested for older adults. However, there is no consensus whether exercising older adults present better strength levels and body composition indexes compared with inactive counterparts. Our aim was to compare absolute and relative isokinetic muscular knee strength and body composition between exercising and non-exercising older women. Exercising (n = 20) and non-exercising (n = 21) groups were evaluated for body mass index (BMI), body composition, and isokinetic muscular knee strength. BMI (p = 0.005), total body mass (p = 0.01), fat mass (p = 0.01), and fat mass percentage (p = 0.01) were higher in non-exercising women, and the lean mass percentage was lower in the non-exercising group (p = 0.01). Isokinetic extensor and flexor knee muscle strength for dominant limbs presented higher peak torque values when corrected for total body mass (Nm·kg⁻¹) in the exercising group (p < 0.05). Exercising older women presented better body composition and higher strength relative to total body mass, but not maximum absolute strength.

Body Composition, IGF1 Status, and Physical Functionality in Nonagenarians: Implications for Osteosarcopenia

OBJECTIVES

Body composition alterations occur during aging. The purpose of the present analysis was to explore the functional consequences of the overlap of sarcopenia and osteoporosis, and the potential role of insulin-like growth factor 1 (IGF1) in their development in the oldest old.

SETTING AND PARTICIPANTS

Eighty-seven nonagenarians from the Louisiana Healthy Aging Study were included.

MEASURES

The definition of sarcopenia was based on appendicular lean mass (ALM). Osteoporosis was diagnosed based on bone mineral density (BMD) T score. Four phenotypes were compared: (1) healthy body composition, that is, nonosteoporotic nonsarcopenic (CO, control group), (2) osteoporotic (O, low BMD T score), (3) sarcopenic (S, low ALM), and (4) osteosarcopenic (OS, low BMD T score and low ALM). Sex- and age-specific IGF1-Standard Deviation Scores (SDS) were calculated. The Continuous Scale-Physical Functional Performance (CS-PFP) test was performed.

RESULTS

In OS men, IGF1-SDS values (-0.61 ±0.37 vs -0.04 ± 0.52, P = .02) were lower than those in CO males (control group), whereas IGF1-SDS were similar in the 4 body composition phenotypes in women. In men only, ALM was positively associated with IGF1-SDS values (P = .01) independent of age and C-reactive protein concentration. Regarding bone health, we found no association between IGF1-SDS values and BMD. IGF1-SDS was not associated with functional performance (CS-PFP) in men and women.

CONCLUSIONS/IMPLICATIONS

IGF1 sensitivity in skeletal muscle and bone may differ by sex in the oldest old. IGF1 status did not appear to affect physical functionality. Determinants and clinical and functional characteristics of osteosarcopenia need to be further investigated in order to define conclusive diagnostic criteria.

Obesity in the global haemophilia population: prevalence, implications and expert opinions for weight management

Overweight and obesity may carry a significant disease burden for patients with haemophilia (PWH), who experience reduced mobility due to joint inflammation, muscle dysfunction and haemophilic arthropathy. This review aimed to define the prevalence and clinical impact of overweight/obesity in the global population of PWH. A detailed literature search pertaining to overweight/obesity in haemophilia in the last 15 years (2003-2018) was conducted, followed by a meta-analysis of epidemiological data. The estimated pooled prevalence of overweight/obesity in European and North American PWH was 31%. Excess weight in PWH is associated with a decreased range in motion of joints, accelerated loss of joint mobility and increase in chronic pain. Additionally, the cumulative disease burden of obesity and haemophilia may impact the requirement for joint surgery, occurrence of perioperative complications and the prevalence of anxiety and depression that associates with chronic illness. Best practice guidelines for obesity prevention and weight management, based on multidisciplinary expert perspectives, are considered for adult and paediatric PWH. Recommendations in the haemophilia context emphasize the importance of patient education and tailoring engagement in physical activity to avoid the risk of traumatic bleeding.

Sarcopenic obesity

Sarcopenic obesity, a chronic condition, is today a major public health problem with increasing prevalence worldwide, which is due to progressively aging populations, the increasing prevalence of obesity, and the changes in lifestyle during the last several decades. Patients usually present to healthcare facilities for obesity and related comorbidities (type 2 diabetes mellitus, non-alcoholic fatty liver disease, dyslipidemia, hypertension, and cardiovascular disease) or for non-specific symptoms related to sarcopenia per se (e.g., fatigue, weakness, and frailty). Because of the non-specificity of the symptoms, sarcopenic obesity remains largely unsuspected and undiagnosed. The pathogenesis of sarcopenic obesity is multifactorial. There is interplay between aging, sedentary lifestyle, and unhealthy dietary habits, and insulin resistance, inflammation, and oxidative stress, resulting in a quantitative and qualitative decline in muscle mass and an increase in fat mass. Myokines, including myostatin and irisin, and adipokines play a prominent role in the pathogenesis of sarcopenic obesity. It has been suggested that a number of disorders affecting metabolism, physical capacity, and quality of life may be attributed to sarcopenic obesity, although it is not as yet established whether sarcopenia and obesity act synergistically. There is to date no approved pharmacological treatment for sarcopenic obesity. The cornerstones of its management are weight loss and adequate protein intake combined with exercise, the latter in order to reduce the loss of muscle mass observed during weight loss following diet unpaired with exercise. A consensus on the definition of sarcopenic obesity is considered essential to facilitate the performance of mechanistic studies and clinical trials aimed at deepening our knowledge, thus enabling improved management of affected individuals in the near future.

Dysmobility Syndrome Independently Increases Fracture Risk in the Osteoporotic Fractures in Men (MrOS) Prospective Cohort Study

We proposed the term "dysmobility syndrome" (DS) to identify individuals with impaired musculoskeletal health, a risk factor for falls and fractures. Whether DS is associated with increased risk of incident fracture is unknown. The Osteoporotic Fractures in Men (MrOS) study enrolled 5994 men ages ≥65 years, between March 2000 and April 2002. We used baseline data to determine whether DS increased fracture risk, independent of the Fracture Risk Assessment Tool (FRAX). Men met DS criteria at baseline if they had three or more of the following: appendicular lean mass/height² <7.26 kg/m² , total body fat >30%, spine or hip T-score ≤ -2.5, grip strength <30 kg, gait speed <1.0 m/s, and one or more fall within 12 months. We examined whether baseline DS increased the risk of hip and major osteoporotic fractures (MOFs) over a median of 14 years (IQR, 9 to 15 years). Among 5834 men mean age 74 ± 6 years, 471 (8%) had DS and 635 (11%) experienced an MOF, including 274 (5%) hip fractures. Age (per SD increase) conferred an HR of 1.72 (95% CI, 1.59 to 1.86), DS conferred an HR of 3.45 (95% CI, 2.78 to 4.29) and FRAX calculated with BMD (per %) conferred an HR of 1.10 (95% CI, 1.08 to 1.11) for MOF. Prediction of MOF using the FRAX score provided a concordance value of 0.67 ± 0.012 (concordance values are mean ± SE). Concordance increased to 0.69 ± 0.012 by adding DS and to 0.70 ± 0.012 by adding DS and age to the multivariate model. Kaplan-Meier curves indicated that men with both DS and a FRAX risk above the National Osteoporosis Foundation (NOF) treatment thresholds had higher MOF (HR 6.23; 95% CI, 3.10 to 12.54) and hip (HR 7.73; 95% CI, 5.95 to 10.04) fracture risk than men with neither condition. We suggest further studies to determine the optimal criteria for DS, and to test DS as a predictor of falls and fractures, especially in women. © 2018 American Society for Bone and Mineral Research.

Does Muscle Atrophy and Fatty Infiltration Plateau or Persist in Chronic Spinal Cord Injury?

Atrophy and fatty infiltration of lower extremity muscle after spinal cord injury (SCI) predisposes individuals to metabolic syndrome and related diabetes and cardiovascular disease. The objective of this study was to prospectively measure changes in muscle atrophy and fat content of distal lower extremity muscles and explore related factors in a cohort of adults with chronic SCI and diverse impairments. Muscle cross-sectional area and density were calculated from peripheral quantitative computed tomography scans of the 66% site of the calf from 70 participants with chronic SCI (50 male, mean age 49 years, C2-T12, American Spinal Injury Association Impairment Scale A-D) at study enrollment and annually for 2 years. Mixed-model repeated measures analysis of variance (rANOVA) examined longitudinal changes in muscle area and density, and regression analyses explored factors related to muscle changes using 16 potential correlates selected a priori. A high degree of individual variation in muscle area and density change was observed over 2 years (range: 8.5 to  -22.6 cm²; 6.4 to -8.6 mg/cm³). Repeated measures analysis of variance revealed significant reductions in muscle area (estimated mean difference [95% confidence intervals] -1.76 [-3.29 to -0.23]) cm², p = 0.025) and density (-1.04 [-1.94 to -0.14] mg/cm³, p < 0.024); however, changes in area were not significant with outliers removed. Regression analyses explained a small proportion of the variability in muscle density change; however, none of the preselected variables were significantly related to changes in muscle density after post hoc sensitivity analyses. Lower extremity muscle size and fat content may not reach a "steady-state" after chronic SCI. Progressive atrophy and fatty infiltration of lower extremity muscle may have adverse implications for metabolic syndrome and cardiovascular disease risk and related mortality after chronic SCI.

Current Status of Sarcopenia in Korea: A Focus on Korean Geripausal Women

Sarcopenia is defined as an age-associated decline in muscle mass and function caused by several etiologies and mechanisms. Muscle mass and function do not decrease concurrently, and a loss of muscle function may be more highly associated with adverse health outcomes. Despite the clinical significance of sarcopenia, no universally operational definition of sarcopenia or standardized intervention programs are currently available. Sarcopenia, osteoporosis, and obesity share several pathophysiological mechanisms, and a combination of these entities may lead to an increased risk of musculoskeletal, cardio-metabolic, and psychological morbidities especially in geripause populations. Treatment for sarcopenia is mainly nonpharmacological, however, various drugs are currently being developed. It is conceivable that sarcopenia is the next immediate clinical target in musculoskeletal science.

Osteosarcopenic obesity and its relationship with dyslipidemia in women from different ethnic groups of China

OBJECTIVES

To explore the prevalence and ethnic differences of osteosarcopenic obesity (OSO) and dyslipidemia and their relationship among Maonan, Mulam, Hmong, and Yao minorities in China.

METHODS

A total of 2315 Maonan, Mulam, Hmong, and Yao women aged 20-95 from Guangxi were included in this study. Questionnaire survey was carried out and their blood lipids were tested. Body compositions were measured by bioelectrical impedance analysis, and T-score was assessed by ultrasonic examination, respectively.

RESULTS

Our study showed ethnic-specific prevalence of OSO. In older women, the incidence rates of OSO in Mulam were 4.9, 12.6, and 11.5% in Maonan, Mulam, and Hmong ethnicity, respectively. In younger group, the incidence rates of OSO were 0.4, 0.4, and 0.6%, respectively. However, there is no prevalence of OSO in Yao women in two groups. The prevalence of dyslipidemia in younger women was 22.86, 29.89, 43.35, and 80.00% in group numbering one, two, and three, respectively. In older women, it was 29.13, 39.02, 41.37, and 52.38%, respectively. Based on logistic regression analysis, after controlling for covariates, dyslipidemia in younger group was positively associated with a higher number of adverse body composition, especially for OSO (OR = 12.53, 95%CI 1.34-116.99). Compared with normal women, OSO women in older group were also more likely to have dyslipidemia (OR = 6.75, 95%CI 3.19-14.31).

CONCLUSION

OSO may be a risk factor for dyslipidemia in the ethnic groups. Thus, efforts to promote healthy aging should be focused on preventing obesity and maintaining bone health and muscle mass.

Prediction of sarcopenia using a combination of multiple serum biomarkers

Sarcopenia is a gradual loss of skeletal muscle mass and function with aging. Given that sarcopenia has been recognized as a disease entity, effective molecular biomarkers for early diagnosis are required. We recruited 46 normal subjects and 50 patients with moderate sarcopenia aged 60 years and older. Sarcopenia was clinically identified on the basis of the appendicular skeletal muscle index by applying cutoff values derived from the Asian Working Group for Sarcopenia. The serum levels of 21 potential biomarkers were analyzed and statistically examined. Interleukin 6, secreted protein acidic and rich in cysteine, macrophage migration inhibitory factor, and insulin-like growth factor 1 levels differed significantly between the normal and sarcopenia groups. However, in each case, the area under the receiver operating characteristics curve (AUC) was <0.7. Subsequent combination of the measurements of these biomarkers into a single risk score based on logistic regression coefficients enhanced the accuracy of diagnosis, yielding an AUC value of 0.763. The best cutoff value of 1.529 had 70.0% sensitivity and 78.3% specificity (95% CI = 2.80–21.69, p < 0.0001). Combined use of the selected biomarkers provides higher diagnostic accuracy than individual biomarkers, and may be effectively utilized for early diagnosis and prognosis of sarcopenia.

A study on the characteristics of standing posture of elderly women with sarcopenia in Korea

This study intended to analyze the characteristics of standing posture and factors related to sarcopenia of elderly women in Korea to provide basic data for the development of rehabilitation programs designed to prevent and control of the sarcopenia of elderly women. A total of 194 elderly women, aged over 65 years old, living in Gyeonggi-do, were selected to diagnose the presence of sarcopenia through bioelectrical impedance analysis (BIA) and muscle function test (gait speed and grip strength). The subjects were then distinguished into normal group (NG=92), presarcopenia group (PG=86), and sarcopenia group (SG=16); the standing posture of elderly women was captured with the three-dimensional (3D) imaging technique (PA200), and an analysis of variance (ANOVA) was carried out for the collected data through IBM SPSS Statistics ver. 23.0. The frontal measurements of standing posture, the pelvic level, R-patella center, and L-patella center, appeared with significant differences from each other whereas, the side measurements of standing posture, the R-earhole position, L-earhole position, R-shoulder position, L-shoulder position, R-pelvic angle, L-pelvic angle, R-knee position, and L-knee position, were also found with significant differences from each other. As a consequence, an intervention to be focusing on obese control was found necessary to prevent or to delay the presence of sarcopenia of elderly women. The positional displacement found from head, knee, and pelvis also necessitates the introduction of rehabilitation program customized for elderly women suffering the sarcopenia.

Osteosarcopenic Visceral Obesity and Osteosarcopenic Subcutaneous Obesity, Two New Phenotypes of Sarcopenia: Prevalence, Metabolic Profile, and Risk Factors

Background

The main criticism of the definition of “osteosarcopenic obesity” (OSO) is the lack of division between subcutaneous and visceral fat. This study describes the prevalence, metabolic profile, and risk factors of two new phenotypes of sarcopenia: osteosarcopenic visceral obesity (OSVAT) and osteosarcopenic subcutaneous obesity (OSSAT).

Methods

A standardized geriatric assessment was performed by anthropometric and biochemical measures. Dual-energy X-ray absorptiometry (DXA) was used to assess body composition, visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), osteoporosis, and sarcopenia.

Results

A sample of 801 subjects were assessed (247 men; 554 women). The prevalence of osteosarcopenic obesity (OSO) was 6.79%; OSSAT and OSOVAT were, respectively, 2.22% and 4.56%. OSVAT (versus the others) showed a higher level of inflammation (CRP and ESR, p < 0.05), bilirubin (p < 0.05), and risk of fractures (FRAX index over 15%, p < 0.001). Subjects with OSSAT did not show any significant risk factors associated to obesity.

Conclusions

The osteosarcopenic visceral obesity phenotype (OSVAT) seems to be associated with a higher risk of fractures, inflammation, and a worse metabolic profile. These conditions in OSVAT cohort are associated with an increase of visceral adipose tissue, while patients with OSSAT seem to benefit related to the “obesity paradox”.

Good, Bad, or Ugly: the Biological Roles of Bone Marrow Fat

PURPOSE OF REVIEW

Bone marrow fat expresses mixed characteristics, which could correspond to white, brown, and beige types of fat. Marrow fat could act as either energy storing and adipokine secreting white fat or as a source of energy for hematopoiesis and bone metabolism, thus acting as brown fat. However, there is also a negative interaction between marrow fat and other elements of the bone marrow milieu, which is known as lipotoxicity. In this review, we will describe the good and bad roles of marrow fat in the bone, while focusing on the specific components of the negative effect of marrow fat on bone metabolism.

RECENT FINDINGS

Lipotoxicity in the bone is exerted by bone marrow fat through the secretion of adipokines and free fatty acids (FFA) (predominantly palmitate). High levels of FFA found in the bone marrow of aged and osteoporotic bone are associated with decreased osteoblastogenesis and bone formation, decreased hematopoiesis, and increased osteoclastogenesis. In addition, FFA such as palmitate and stearate induce apoptosis and dysfunctional autophagy in the osteoblasts, thus affecting their differentiation and function. Regulation of marrow fat could become a therapeutic target for osteoporosis. Inhibition of the synthesis of FFA by marrow fat could facilitate osteoblastogenesis and bone formation while affecting osteoclastogenesis. However, further studies testing this hypothesis are still required.

The androgen receptor in bone marrow progenitor cells negatively regulates fat mass

It is well established that testosterone negatively regulates fat mass in humans and mice; however, the mechanism by which testosterone exerts these effects is poorly understood. We and others have shown that deletion of the androgen receptor (AR) in male mice results in a phenotype that mimics the three key clinical aspects of hypogonadism in human males; increased fat mass and decreased bone and muscle mass. We now show that replacement of the Ar gene specifically in mesenchymal progenitor cells (PCs) residing in the bone marrow of Global-ARKO mice, in the absence of the AR in all other tissues (PC-AR Gene Replacements), completely attenuates their increased fat accumulation. Inguinal subcutaneous white adipose tissue and intra-abdominal retroperitoneal visceral adipose tissue depots in PC-AR Gene Replacement mice were 50-80% lower than wild-type (WT) and 75-90% lower than Global-ARKO controls at 12 weeks of age. The marked decrease in subcutaneous and visceral fat mass in PC-AR Gene Replacements was associated with an increase in the number of small adipocytes and a healthier metabolic profile compared to WT controls, characterised by normal serum leptin and elevated serum adiponectin levels. Euglycaemic/hyperinsulinaemic clamp studies reveal that the PC-AR Gene Replacement mice have improved whole-body insulin sensitivity with higher glucose infusion rates compared to WT mice and increased glucose uptake into subcutaneous and intra-abdominal fat. In conclusion, these data provide the first evidence for an action of androgens via the AR in mesenchymal bone marrow PCs to negatively regulate fat mass and improve metabolic function.

Comparison of muscle/lean mass measurement methods: correlation with functional and biochemical testing

DXA-measured lean mass is often used to assess muscle mass but has limitations. Thus, we compared DXA lean mass with two novel methods-bioelectric impedance spectroscopy and creatine (methyl-d3) dilution. The examined methodologies did not measure lean mass similarly and the correlation with muscle biomarkers/function varied.

INTRODUCTION

Muscle function tests predict adverse health outcomes better than lean mass measurement. This may reflect limitations of current mass measurement methods. Newer approaches, e.g., bioelectric impedance spectroscopy (BIS) and creatine (methyl-d3) dilution (D3-C), may more accurately assess muscle mass. We hypothesized that BIS and D3-C measured muscle mass would better correlate with function and bone/muscle biomarkers than DXA measured lean mass.

METHODS

Evaluations of muscle/lean mass, function, and serum biomarkers were obtained in older community-dwelling adults. Mass was assessed by DXA, BIS, and orally administered D3-C. Grip strength, timed up and go, and jump power were examined. Potential muscle/bone serum biomarkers were measured. Mass measurements were compared with functional and serum data using regression analyses; differences between techniques were determined by paired t tests.

RESULTS

Mean (SD) age of the 112 (89F/23M) participants was 80.6 (6.0) years. The lean/muscle mass assessments were correlated (.57-.88) but differed (p < 0.0001) from one another with DXA total body less head being highest at 37.8 (7.3) kg, D3-C muscle mass at 21.1 (4.6) kg, and BIS total body intracellular water at 17.4 (3.5) kg. All mass assessment methods correlated with grip strength and jump power (R = 0.35-0.63, p < 0.0002), but not with gait speed or repeat chair rise. Lean mass measures were unrelated to the serum biomarkers measured.

CONCLUSIONS

These three methodologies do not similarly measure muscle/lean mass and should not be viewed as being equivalent. Functional tests assessing maximal muscle strength/power (grip strength and jump power) correlated with all mass measures whereas gait speed was not. None of the selected serum measures correlated with mass. Efforts to optimize muscle mass assessment and identify their relationships with health outcomes are needed.

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.

The sarcopenia index: A novel measure of muscle mass in lung transplant candidates

BACKGROUND

Frailty, including low muscle mass, is an emerging risk factor for poor outcomes after lung transplant. The sarcopenia index (SI)-(serum creatinine value/cystatin C value) × 100-is a novel blood test to approximate muscle mass. We sought to validate SI among lung transplant patients.

METHODS

We retrospectively identified adult lung transplant recipients from 2000 through 2012 at our institution who underwent computed tomography within 1 year before transplant and had preserved blood samples. Creatinine and cystatin C values were measured using the samples and used to calculate SI. Muscle mass was estimated by computed tomographic measurement of skeletal muscle cross-sectional surface area (SA) at the L1 to L3 vertebral levels. Correlation between SI and SA was evaluated.

RESULTS

Of 28 patients meeting eligibility criteria, most were white (96%) and men (54%). Median (interquartile range) body mass index, SI, and SA were 25.9 (22-30) kg/m² , 106 (91-119), and 157 (113-195) cm2, respectively. The Pearson correlation coefficient between SI and SA was significant at L2 (0.43; P = .02) and L3 (0.41; P = .03).

CONCLUSION

Sarcopenia index is a potentially objective measure for estimating muscle mass that is noninvasive and less expensive. Sarcopenia index could be considered in lung transplant candidate selection following prospective validation in larger cohorts.

The risks of sarcopenia, falls and fractures in patients with type 2 diabetes mellitus

Fracture risk in patients with type 2 diabetes mellitus (T2DM) is increased, and the mechanism is multifactorial. Recent research on T2DM-induced bone fragility shows that bone mineral density (BMD) is often normal or even slightly elevated. However, bone turnover may be decreased and bone material and microstructural properties are altered, especially when microvascular complications are present. Besides bone fragility, extra-skeletal factors leading to an increased propensity to experience falls may also contribute to the increased fracture risk in T2DM, such as peripheral neuropathy, retinopathy and diabetes medication (e.g. insulin use). One of the probable additional contributing factors to the increased fall and fracture risks in T2DM is sarcopenia, the age-related decline in skeletal muscle mass, quality and function. Although the association between sarcopenia, fall risk, and fracture risk has been studied in the general population, few studies have examined the association between T2DM and muscle tissue and the risks of falls and fractures. This narrative review provides an overview of the literature regarding the multifactorial mechanisms leading to increased fracture risk in patients with T2DM, with a focus on sarcopenia and falls.

The effects of resistance training volume on osteosarcopenic obesity in older women

The aim of this study was to analyze the effects of resistance training (RT) performed with 1 or 3 sets per exercise on osteosarcopenic obesity (OSO) syndrome parameters in older women. Sixty-two older women (68.0 ± 4.3 years, 26.8 ± 4.4 kg/m²) participated in a 12-week RT program. Participants were randomly assigned into one of the three groups: two training groups that performed either 1 set (G1S, n = 21) or 3 sets (G3S, n = 20) 3 times weekly, or a control group (CG, n = 21). Body composition was assessed by dual X-ray absorptiometry, strength was evaluated by 1 repetition maximum testing. The G3S presented significantly higher strength changes than G1S. The changes for percentage of body fat were higher for G3S compared to G1S. There was no difference in skeletal muscle mass between G3S and G1S, however both training groups displayed greater increases in this outcome compared to CG. There was no effect for bone mineral density. The overall analysis indicated higher (P < 0.05) positive changes for G3S than G1S (composed Z-score: G3S = 0.62 ± 0.40; G1S = 0.11 ± 0.48). The results suggest that a 12-week RT period is effective to improve the risk factors of OSO, and that 3 sets induce higher improvements than a single set.

Factors Influencing Influenza Vaccination Among Patients With Chronic Obstructive Pulmonary Disease: A Population-Based Cross-sectional Study

This study aimed to investigate the factors associated with vaccination coverage among chronic obstructive pulmonary disease (COPD) patients in Korea using the fourth to the sixth Korean National Health and Nutrition Examination Surveys (KNHANES IV, V, VI). A total of 16 812 subjects aged 40 years and older who underwent spirometry and had an "influenza vaccination history" were analyzed. The vaccination rate of middle-aged (40-64 years) COPD patients was only 31.9%; whereas, the vaccination rate of elderly (65 years and older) COPD patients was 80.0%. The results of a multiple regression analysis indicated that older age (odds ratio [OR], 1.12; 95% confidence interval [95% CI], 1.09-1.14), poor self-rated health status (OR, 1.45; 95% CI, 1.14-1.95), regular health check-up (OR, 2.61; 95% CI, 1.93-3.51), married marital status (OR, 0.64; 95% CI, 0.42-0.96), and household income below average (OR, 0.72; 95% CI, 0.53-0.98) were associated with influenza vaccination. More attention and targeted interventions are required to improve the influenza vaccination rate of COPD patients.

Molecular mechanisms and therapeutic interventions in sarcopenia

Sarcopenia is the degenerative loss of muscle mass and function with aging. Recently sarcopenia was recognized as a clinical disease by the International Classification of Disease, 10th revision, Clinical Modification. An imbalance between protein synthesis and degradation causes a gradual loss of muscle mass, resulting in a decline of muscle function as a progress of sarcopenia. Many mechanisms involved in the onset of sarcopenia include age-related factors as well as activity-, disease-, and nutrition-related factors. The stage of sarcopenia reflecting the severity of conditions assists clinical management of sarcopenia. It is important that systemic descriptions of the disease conditions include age, sex, and other environmental risk factors as well as levels of physical function. To develop a new therapeutic intervention needed is the detailed understanding of molecular and cellular mechanisms by which apoptosis, autophagy, atrophy, and hypertrophy occur in the muscle stem cells, myotubes, and/or neuromuscular junction. The new strategy to managing sarcopenia will be signal-modulating small molecules, natural compounds, repurposing of old drugs, and muscle-specific microRNAs.

Cushing's syndrome: a model for sarcopenic obesity

PURPOSE

Obesity and its metabolic impairments are discussed as major risk factors for sarcopenia leading to sarcopenic obesity. Cushing's syndrome is known to be associated with obesity and muscle atrophy. We compared Cushing's syndrome with matched obese controls regarding body composition, physical performance, and biochemical markers to test the hypothesis that Cushing's syndrome could be a model for sarcopenic obesity.

METHODS

By propensity score matching, 47 controls were selected by body mass index and gender as obese controls. Fat mass and muscle mass were measured by bioelectrical impedance analysis. Muscle function was assessed by chair rising test and hand grip strength. Biochemical markers of glucose and lipid metabolism and inflammation (hsCRP) were measured in peripheral blood.

RESULTS

Muscle mass did not differ between Cushing's syndrome and obese controls. However, Cushing's syndrome patients showed significantly greater chair rising time (9.5 s vs. 7.3 s, p = 0.008) and significantly lower hand grip strength (32.1 kg vs. 36.8 kg, p = 0.003). Cushing's syndrome patients with impaired fasting glucose have shown the highest limitations in hand grip strength and chair rising time.

CONCLUSIONS

Similar to published data in ageing medicine, Cushing's syndrome patients show loss of muscle function that cannot be explained by loss of muscle mass. Impaired muscle quality due to fat infiltration may be the reason. This is supported by the observation that Cushing's syndrome patients with impaired glucose metabolism show strongest deterioration of muscle function. Research in sarcopenic obesity in elderly is hampered by confounding comorbidities and polypharmacy. As Cushing's syndrome patients are frequently free of comorbidities and as Cushing's syndrome is potentially curable we suggest Cushing's syndrome as a clinical model for further research in sarcopenic obesity.

Diet quality and osteosarcopenic obesity in community-dwelling adults 50 years and older

OBJECTIVES

To examine the association between diet quality and osteosarcopenic obesity (OSO), low bone and muscle mass with concurrent high fat mass, in middle-aged and older adults.

STUDY DESIGN

Data were from a cross-sectional study of 2579 men and 3550 women aged 50 years and older who completed the Korea National Health and Nutritional Examination Survey from 2008 to 2010.

MAIN OUTCOME MEASURES

Data were collected using 24-h dietary recall, and diet quality was determined by the Diet Quality Index-International (DQI-I), on which higher scores denote better quality. Body composition was evaluated by dual-energy x-ray absorptiometry. The association between dietary quality and the number of body composition abnormalities (including OSO) was analyzed by multinomial logistic regression, adjusting for covariates.

RESULTS

In women, after controlling for covariates, higher scores on the DQI-I were associated with a significantly lower number of phenotypes associated with adverse body composition. Those in the highest tertile group of DQI-I were less likely to have OSO compared with those in the lowest tertile (odds ratio=0.54, 95% confidence interval: 0.32-0.92). In men, DQI-I scores were not associated with the number of body composition abnormalities.

CONCLUSIONS

Middle-aged and older women who eat a healthier diet, as determined by a high DQI-I score, are less likely to have multiple body composition abnormalities.

Aging human body: changes in bone, muscle and body fat with consequent changes in nutrient intake

Aging affects almost all physiological processes, but changes in body composition and body phenotype are most observable. In this review, we focus on these changes, including loss of bone and muscle and increase in body fat or redistribution of the latter, possibly leading to osteosarcopenic obesity syndrome. We also address low-grade chronic inflammation, prevalent in aging adults and a cause of many disorders including those associated with body composition. Changes in dietary intake and nutritional requirements of older individuals, that all may lead to some disturbances on tissue and organ levels, are discussed as well. Finally, we discuss the hormonal changes in the aging body, considering each of the tissues, bone, muscle and fat as separate endocrine organs, but yet in the continuous interface and communication with each other. Although there are still many unanswered questions in this field, this review will enable the readers to better understand the aging human body and measures needing to be implemented toward reducing impaired health and disability in older individuals.

Evaluating Muscle Mass by Using Markers of Kidney Function: Development of the Sarcopenia Index

OBJECTIVES

Sarcopenia is associated with a poor prognosis in the ICU. The purpose of this study was to describe a simple sarcopenia index using routinely available renal biomarkers and evaluate its association with muscle mass and patient outcomes.

DESIGN

A retrospective cohort study.

SETTING

A tertiary-care medical center.

PATIENTS

High-risk adult ICU patients from October 2008 to December 2010.

INTERVENTIONS

The gold standard for muscle mass was quantified with the paraspinal muscle surface area at the L4 vertebrae in the subset of individuals with an abdominal CT scan. Using Pearson's correlation coefficient, serum creatinine-to-serum cystatin C ratio was found to be the best performer in the estimation of muscle mass. The relationship between sarcopenia index and hospital and 90-day mortality, and the length of mechanical ventilation was evaluated.

MEASUREMENTS AND MAIN RESULTS

Out of 226 enrolled patients, 123 (54%) were female, and 198 (87%) were white. Median (interquartile range) age, body mass index, and body surface area were 68 (57-77) years, 28 (24-34) kg/m, and 1.9 (1.7-2.2) m, respectively. The mean (± SD) Acute Physiology and Chronic Health Evaluation III was 70 (± 22). ICU, hospital, and 90-day mortality rates were 5%, 12%, and 20%, respectively. The correlation (r) between sarcopenia index and muscle mass was 0.62 and coefficient of determination (r) was 0.27 (p < 0.0001). After adjustment for Acute Physiology and Chronic Health Evaluation III, body surface area, and age, sarcopenia index was independently predictive of both hospital (p = 0.001) and 90-day mortality (p < 0.0001). Among the 131 patients on mechanical ventilator, the duration of mechanical ventilation was significantly lower on those with higher sarcopenia index (-1 d for each 10 unit of sarcopenia index [95% CI, -1.4 to -0.2; p = 0.006]).

CONCLUSIONS

The sarcopenia index is a fair measure for muscle mass estimation among ICU patients and can modestly predict hospital and 90-day mortality among patients who do not have acute kidney injury at the time of measurement.

Factors influencing influenza vaccination among South Korean adult asthma patients: A nationwide population-based cross-sectional study

BACKGROUND

It is important to identify factors associated with influenza vaccination. This study was performed to investigate factors associated with vaccination coverage among asthma patients in Korea.

METHODS

Data were obtained from 229,121 participants (5,989 with asthma and 223,132 without asthma) in the 2010 Korean Community Health Survey. The demographic characteristics and socioeconomic status of respondents with and without asthma were compared. Univariate and multiple logistic regression analyses were used to evaluate socioeconomic status and other demographic variables potentially related to influenza vaccination in asthma patients.

RESULTS

The vaccination rates of young (19-49 years) and middle-aged (50-64 years) asthma patients were only 28.3 and 49.5%, respectively, whereas that of elderly (≥65 years) asthma patients was 81.5%. After regression, older age (odds ratio [OR], 5.53; 95% confidence interval [95% CI], 3.56-8.59), poor self-rated health status (OR, 1.43; 95% CI, 1.01-2.03), and regular health check-ups (OR, 2.07, 95% CI, 1.64-2.60) were associated with increased influenza vaccination rates in asthma patients.

CONCLUSIONS

It is important to improve influenza vaccination coverage for non-elderly patients with asthma, especially those who do not engage in regular exercise or undergo regular health check-ups and those who consider themselves to be healthy.

Sarcopenic obesity or obese sarcopenia: A cross talk between age-associated adipose tissue and skeletal muscle inflammation as a main mechanism of the pathogenesis

Sarcopenia, an age-associated decline in skeletal muscle mass coupled with functional deterioration, may be exacerbated by obesity leading to higher disability, frailty, morbidity and mortality rates. In the combination of sarcopenia and obesity, the state called sarcopenic obesity (SOB), some key age- and obesity-mediated factors and pathways may aggravate sarcopenia. This review will analyze the mechanisms underlying the pathogenesis of SOB. In obese adipose tissue (AT), adipocytes undergo hypertrophy, hyperplasia and activation resulted in accumulation of pro-inflammatory macrophages and other immune cells as well as dysregulated production of various adipokines that together with senescent cells and the immune cell-released cytokines and chemokines create a local pro-inflammatory status. In addition, obese AT is characterized by excessive production and disturbed capacity to store lipids, which accumulate ectopically in skeletal muscle. These intramuscular lipids and their derivatives induce mitochondrial dysfunction characterized by impaired β-oxidation capacity and increased reactive oxygen species formation providing lipotoxic environment and insulin resistance as well as enhanced secretion of some pro-inflammatory myokines capable of inducing muscle dysfunction by auto/paracrine manner. In turn, by endocrine manner, these myokines may exacerbate AT inflammation and also support chronic low grade systemic inflammation (inflammaging), overall establishing a detrimental vicious circle maintaining AT and skeletal muscle inflammation, thus triggering and supporting SOB development. Under these circumstances, we believe that AT inflammation dominates over skeletal muscle inflammation. Thus, in essence, it redirects the vector of processes from "sarcopenia→obesity" to "obesity→sarcopenia". We therefore propose that this condition be defined as "obese sarcopenia", to reflect the direction of the pathological pathway.

Fat Mass Is Positively Associated with Estimated Hip Bone Strength among Chinese Men Aged 50 Years and above with Low Levels of Lean Mass

This study investigated the relationships of fat mass (FM) and lean mass (LM) with estimated hip bone strength in Chinese men aged 50-80 years (median value: 62.0 years). A cross-sectional study including 889 men was conducted in Guangzhou, China. Body composition and hip bone parameters were generated by dual-energy X-ray absorptiometry (DXA). The relationships of the LM index (LMI) and the FM index (FMI) with bone phenotypes were detected by generalised additive models and multiple linear regression. The associations between the FMI and the bone variables in LMI tertiles were further analysed. The FMI possessed a linear relationship with greater estimated hip bone strength after adjustment for the potential confounders (p < 0.05). Linear relationships were also observed for the LMI with most bone phenotypes, except for the cross-sectional area (p < 0.05). The contribution of the LMI (4.0%-12.8%) was greater than that of the FMI (2.0%-5.7%). The associations between the FMI and bone phenotypes became weaker after controlling for LMI. Further analyses showed that estimated bone strength ascended with FMI in the lowest LMI tertile (p < 0.05), but not in the subgroups with a higher LMI. This study suggested that LM played a critical role in bone health in middle-aged and elderly Chinese men, and that the maintenance of adequate FM could help to promote bone acquisition in relatively thin men.

Osteosarcopenic Obesity: Prevalence and Relation With Frailty and Physical Performance in Middle-Aged and Older Women

OBJECTIVES

The aims of this study were to determine the prevalence of osteosarcopenic obesity (OSO) and to investigate its association with frailty and physical performance in Mexican community-dwelling middle-aged and older women.

DESIGN

Cross-sectional analysis of a prospective cohort.

SETTING

The FraDySMex study, a 2-round evaluation of community-dwelling adults from 2 municipalities in Mexico City.

PARTICIPANTS

Participants were 434 women aged 50 years or older, living in the designated area in Mexico City.

MEASUREMENTS

Body composition was measured with dual-energy X-ray absorptiometry and OSO was defined by the coexistence of sarcopenia, osteopenia, or osteoporosis and obesity. Information regarding demographic characteristics; comorbidities; mental status; nutritional status; and history of falls, fractures, and hospitalization was obtained from questionnaires. Objective measurements of muscle strength and function were grip strength using a hand dynamometer, 6-meter gait speed using a GAIT Rite instrumented walkway, and lower extremity functioning measured by the Short Physical Performance Battery (SPPB). Frailty was assessed using the Frailty Phenotype (Fried criteria), the Gerontopole Frailty Screening Tool (GFST), and the FRAIL scale, to build 3 logistic regression models.

RESULTS

The prevalence of OSO was 19% (n = 81). Frailty (according to the Frailty Phenotype and the GFST) and poor physical performance measured by the SPPB were independently associated with OSO, controlled by age. In the logistic regression model assessing frailty with the Frailty Phenotype, the odds ratio (95% confidence interval) for frailty was 4.86 (2.47-9.55), and for poor physical performance it was 2.11 (1.15-3.89). In the model assessing frailty with the GFST, it was 2.12 (1.10-4.11), and for poor physical performance it was 2.15 (1.18-3.92). Finally, in the model with the FRAIL scale, it was 1.69 (0.85-3.36) for frailty and 2.29 (1.27-4.15) for poor physical performance.

CONCLUSION

OSO is a frequent condition in middle-aged and older women, and it is independently associated with frailty and poor physical performance.

Association of serum vitamin D with osteosarcopenic obesity: Korea National Health and Nutrition Examination Survey 2008-2010

BACKGROUND

Serum vitamin D levels have been reported to be associated with individual components of body composition. However, the relationship between serum vitamin D and combined indices of adverse body composition is largely unknown. This cross-sectional study examined the association between serum vitamin D and osteosarcopenic obesity in a nationally representative sample of middle-aged and older adults.

METHODS

We analysed the Korea National Health and Nutrition Examination Surveys (IV and V) conducted in 2008-2010, consisting of 5908 (2485 men, 3423 women) aged ≥ 50 years. Serum vitamin D levels were determined by radioimmunoassay, and body composition was evaluated by dual-energy x-ray absorptiometry. The association between serum vitamin D levels and the number of abnormalities in body composition, including osteosarcopenic obesity, a low bone and muscle mass with concurrent high fat mass, was analysed by multinomial logistic regression adjusting for covariates.

RESULTS

In men, after controlling for covariates, higher vitamin D levels were associated with a significantly reduced likelihood of the number of phenotypes of adverse body composition (P for trend < 0.05). Those in the highest tertile group of serum vitamin D levels, compared with those in the lowest tertile, were less likely to have adverse body composition, numbering one (odds ratio [OR] = 0.67, 95% confidence interval [CI]: 0.49, 0.92), two (OR = 0.49, 95% CI: 0.33, 0.73), and three (osteosarcopenic obesity; OR = 0.42, 95% CI: 0.26, 0.67). In women, those in the highest tertile group of serum vitamin D levels, compared with those in the lowest tertile, were less likely to have osteosarcopenic obesity (OR = 0.55, 95% CI: 0.33, 0.93). Vitamin D deficiency (<20 ng/mL) in men was significantly associated with an increased likelihood of a higher number of adverse body composition, especially for osteosarcopenic obesity (OR = 2.08, 95% CI: 1.42, 3.03). Vitamin D deficient women, compared with those having normal levels of serum vitamin D, were also more likely to demonstrate osteosarcopenic obesity (OR = 1.99, 95% CI: 1.30, 3.05).

CONCLUSIONS

A high serum vitamin D level in mid- and late-life was associated with reduced odds of multiple adverse body composition, especially osteosarcopenic obesity, suggesting potential health benefits of maintaining adequate levels of vitamin D.

Osteosarcopenic obesity in women: impact, prevalence, and management challenges

Osteosarcopenic obesity syndrome (OSO) has recently been identified as a condition encompassing osteopenia/osteoporosis, sarcopenia and obesity. OSO is especially deleterious in older adults (even if they are not obese by conventional measures), due to age-related redistribution of fat and its infiltration into bone and muscle. Osteoporosis and bone fractures in elderly increase the risk of sarcopenia, which, through decreased mobility, increases the risk of more falls and fractures, creating a vicious cycle. Obesity plays a dual role: to a certain extent, it promotes bone and muscle gains through mechanical loading; in contrast, increased adiposity is also a source of pro-inflammatory cytokines and other endocrine factors that impair bone and muscle. As the elderly population increases, changes in lifestyle to delay the onset of OSO, or prevent OSO, are warranted. Among these changes, dietary patterns and physical activity modifications are the first ones to be implemented. The typical Western diet (and lifestyle) promotes several chronic diseases including OSO, by facilitating a pro-inflammatory state, largely via the imbalance in omega-6/omega-3 fatty acid ratio and low-fiber and high-processed food consumption. Nutritional modifications to prevent and/or alleviate the OSO syndrome include adequate intake of protein, calcium, magnesium and vitamin D and increasing consumptions of foods containing omega-3 polyunsaturated fatty acids and fiber. Certain types of physical activity, often decreased in overweight/obese women and in elderly, might preserve bone and muscle, as well as help in reducing body fat accrual and fat infiltration. Habitual daily activities and some alternative modes of exercise may be more appropriate for older adults and play a crucial role in preventing bone and muscle loss and maintaining optimal weight. In conclusion, older adults who suffer from OSO syndrome may benefit from combined efforts to improve diet and physical activity, and such recommendations should be fostered as part of public health programs.

Mechanisms involved in altered bone metabolism in diabetes: a narrative review

Many studies have shown that change in metabolism caused by diabetes can influence the bone metabolism in a way that quality and strength of bone is decreased. A 6 times and 2 times increased risk of fracture is reported in patients with type 1 and type 2 diabetes, respectively. There are several mechanisms by which diabetes can affect the bone. The fact that some of these mechanisms are acting in opposite ways opens the door for debate on pathways by which diabetes affects the bones. On the other hand, bone is not a simple organ that only get influence from other organs, but it is an endocrine organ that by secreting the agents such as osteocalcin, adiponectin and visfatin which can affect the insulin sensitivity and metabolism. In this paper we tried to briefly assess the latest finding in this matter.

Implications of exercise-induced adipo-myokines in bone metabolism

Physical inactivity has been recognized, by the World Health Organization as the fourth cause of death (5.5 % worldwide). On the contrary, physical activity (PA) has been associated with improved quality of life and decreased risk of several diseases (i.e., stroke, hypertension, myocardial infarction, obesity, malignancies). Bone turnover is profoundly affected from PA both directly (load degree is the key determinant for BMD) and indirectly through the activation of several endocrine axes. Several molecules, secreted by muscle (myokines) and adipose tissues (adipokines) in response to exercise, are involved in the fine regulation of bone metabolism in response to the energy availability. Furthermore, bone regulates energy metabolism by communicating its energetic needs thanks to osteocalcin which acts on pancreatic β-cells and adipocytes. The beneficial effects of exercise on bone metabolism depends on the intermittent exposure to myokines (i.e., irisin, IL-6, LIF, IGF-I) which, instead, act as inflammatory/pro-resorptive mediators when chronically elevated; on the other hand, the reduction in the circulating levels of adipokines (i.e., leptin, visfatin, adiponectin, resistin) sustains these effects as well as improves the whole-body metabolic status. The aim of this review is to highlight the newest findings about the exercise-dependent regulation of these molecules and their role in the fine regulation of bone metabolism.

Osteosarcopenic Obesity Syndrome: What Is It and How Can It Be Identified and Diagnosed?

Conditions related to body composition and aging, such as osteopenic obesity, sarcopenia/sarcopenic obesity, and the newly termed osteosarcopenic obesity (triad of bone muscle and adipose tissue impairment), are beginning to gain recognition. However there is still a lack of definitive diagnostic criteria for these conditions. Little is known about the long-term impact of these combined conditions of osteoporosis, sarcopenia, and obesity in older adults. Many may go undiagnosed and progress untreated. Therefore, the objective of this research is to create diagnostic criteria for osteosarcopenic obesity in older women. The proposed diagnostic criteria are based on two types of assessments: physical, via body composition measurements, and functional, via physical performance measures. Body composition measurements such as T-scores for bone mineral density, appendicular lean mass for sarcopenia, and percent body fat could all be obtained via dual energy X-ray absorptiometry. Physical performance tests: handgrip strength, one-leg stance, walking speed, and sit-to-stand could be assessed with minimal equipment. A score could then be obtained to measure functional decline in the older adult. For diagnosing osteosarcopenic obesity and other conditions related to bone loss and muscle loss combined with obesity, a combination of measures may more adequately improve the assessment process.

Healthy overweight/obese youth: early osteosarcopenic obesity features

BACKGROUND

Osteosarcopenic obesity was recently described as a variant phenotype of obesity, mainly observed in old age. This nested case-control study was performed to detect the differences in body composition between young, healthy overweight/obese and healthy lean populations of both genders. Our null hypothesis was that except for the fat mass, there would be absence of body composition differences, namely skeletal muscle and bone masses, between the groups.

METHODS

We used an advanced bio-impedance device to determine the body composition and measured circulating CRP (hsCRP) and diurnal salivary cortisol concentrations, as indices of inflammation and chronic stress, respectively. Overall, 2551 subjects aged 18-21 years participated in the study.

RESULTS

The healthy lean group included 1072 participants [900 males (84%) and 172 females (16%)], and the healthy overweight/obese group included 1479 participants [74 males (5%) and 1405 females (95%)]. Healthy overweight/obese participants presented with an increased fat mass (P < 0·001), as expected, but lower muscle (P < 0·001) and bone (P < 0·001) masses than lean controls. These findings were accompanied by increased extracellular water compartments, circulating hsCRP levels and evening salivary cortisol concentrations in the healthy overweight/obese group.

CONCLUSIONS

Our study suggests that 'osteosarcopenic' elements exist even in very young populations. These may represent a 'precursor' or forme fruste of the osteosarcopenic obesity phenotype in young healthy overweight/obese subjects, who may progressively develop osteosarcopenia in its full form at an older age. Our study highlights the significance of body composition analysis in medical practice, improving prevention and alleviating later health-related economic burden.