Musculoskeletal deterioration in men accompanies increases in body fat

Association between metabolic phenotypes and incident pre-sarcopenia: 3 years follow-up of Tehran Lipid and Glucose Study

OBJECTIVES

In the context of musculoskeletal health, the emergence of pre-sarcopenia as a precursor to sarcopenia has garnered attention for its potential insights into early muscle loss. We explored the association between different metabolic phenotypes of obesity, and the incidence of pre-sarcopenia over a 3-year follow-up in a cohort from the Tehran Lipid and Glucose Study (TLGS).

METHODS

In this 3-year longitudinal study, 2257 participants were categorized into four groups based on their BMI and metabolic status: metabolically healthy normal weight (MHNW), metabolically healthy overweight/obese (MHO), metabolically unhealthy normal weight (MUNW), and metabolically unhealthy overweight/obese (MUO). The participants were assessed for various anthropometric and body composition indices including muscle mass determined by bioelectrical impedance analysis (BIA). Blood samples were collected for metabolic indices, and participants underwent measurements for blood pressure. Pre-sarcopenia was defined based on low muscle mass. Statistical analyses included logistic regression and chi-squared tests.

RESULTS

The MUNW group exhibited the highest prevalence of pre-sarcopenia (33.5%), while the MHO group had the lowest (2.8%). Adjusted models revealed that the odds ratio for pre-sarcopenia was higher in the MUNW group (OR = 2.23, P < 0.001), whereas the MHO and MUO groups showed lower odds (OR = 0.11 and 0.13, both P < 0.001). Notably, the association was gender-dependent, with MUNW females having a higher risk even after adjustments (OR = 2.37, P = 0.042).

CONCLUSION

Our findings suggest that metabolic health may play a pivotal role in pre-sarcopenia, emphasizing the need for targeted interventions based on both metabolic and obesity phenotypes.

%BF, Rather Than BMI, is Associated with an Increased Risk of Sarcopenia in Hospitalized Postmenopausal Chinese Women with Type 2 Diabetes Mellitus

Purpose

To investigate the relationship between obesity indices and sarcopenia in postmenopausal patients with type 2 diabetes mellitus (T2DM) at different body mass index (BMI) levels.

Patients and Methods

This retrospective cross-sectional study included 298 hospitalized postmenopausal women diagnosed with T2DM. We collected demographic, biochemical, and anthropometric data on each subject. Body composition was measured using dual-energy X-ray absorptiometry (DXA), and skeletal muscle mass index (SMI) and body fat percentage (%BF) were calculated. According to BMI stratification, the patients were divided into normal group A (18.5 kg/m2≤BMI < 24 kg/m2), overweight group B (24.0 kg/m2≤BMI < 28 kg/m2), and obesity group C (28.0 kg/m2 ≤BMI < 35 kg/m2).

Results

From group A to group C, SMI (5.21±0.56 vs 5.48±0.56 vs 6.03±0.69) increased gradually (P < 0.05). Logistic regression analysis indicated that for each 1-unit increase in BMI, the risk of sarcopenia decreased by 63.2% (OR=0.368, 95% CI 0.215-0.629, P=0.000) in group A. Age (OR=1.077, 95% CI 1.015-1.144, P=0.015) and %BF (OR=1.094, 95% CI 1.010-1.186, P=0.028) increased the risk of sarcopenia by 1.077 and 1.094 times, respectively, in group B. While every 1-unit increase in BMI, the risk of sarcopenia decreased by 35% (OR=0.650, 95% CI 0.430-0.983, P=0.041) in group B. %BF (OR=1.459, 95% CI 1.093-1.949, P=0.010) increased the risk factors of sarcopenia by 1.459 times in group C.

Conclusion

In postmenopausal patients with T2DM, BMI had a protective effect on the occurrence of sarcopenia within a certain range, and with the increase of BMI, the risk of sarcopenia was increasing by increased %BF levels in overweight and obese patients.

Association of Different Obesity Phenotypes with Sarcopenia in Han Chinese Middle-Aged and Elderly with Type 2 Diabetes Individuals

PURPOSE

To investigate the relationship between different obesity phenotypes and sarcopenia in hospitalized Chinese patients with type 2 diabetes mellitus (T2DM).

METHODS

This cross-sectional study included 385 men. Anthropometric measurements including applied the determination method of Dual-energy X-ray absorptiometry (DXA) determination of limb skeletal muscle mass index (ASMI) and blood samples were analyzed. The people were divided into four groups according to body mass index (BMI) (≥24kg/m²) and waist circumference (WC) (female ≥85cm, male ≥90cm). Group A (BMI and WC were normal), Group B (BMI was normal and high WC), Group C (high BMI and WC were normal), and Group D (BMI and WC were abnormal).

RESULTS

The prevalence rates of sarcopenia and abdominal obesity were 32.2% and 74.0%, respectively. The detection rate of lower ASMI decreased gradually from Group A to Group D(74.6% vs 68.3% vs 54.5% vs 51.6%, χ 2 =14.243, P=0.003). Logistic analysis showed that the risk of lower ASMI were decreased by 62.4% (95% CI: 0.149-0.950, P = 0.039) in Group C and 68.8% (95% CI: 0.165-0.593, P = 0.000) in Group D compared with Group A, respectively. The risk of lower ASMI were increased 4.153-fold (95% CI: 2.623-6.576, P = 0.000) in male. Male (OR = 4.065, 95% CI: 2.246-7.356, P = 0.000) and WC (OR = 1.053, 95% CI: 1.004-1.104, P = 0.033) were risk factors for lower ASMI, but the risk of lower ASMI was decreased by 32% (95% CI: 0.5744-0.804, P = 0.000) by elevated BMI in the overweight and obese group (Group C and Group D).

CONCLUSION

The prevalence of sarcopenia and abdominal obesity was elevated in han Chinese middle-aged and elderly patients with T2DM. Being overweight or obesity as defined by BMI protect against sarcopenia, while abdominal obesity increases the risk of sarcopenia.

Fatty Liver Index and Skeletal Muscle Density

Accumulation of fat in the liver and skeletal muscle is associated with obesity and poor health outcomes. Liver steatosis is a characteristic of non-alcoholic fatty liver disease (NAFLD) and myosteatosis, of poor muscle quality in sarcopenia. In this study of 403 men (33-96 years), we investigated associations between the fatty liver index (FLI) and muscle density, as markers of fat accumulation in these organs. We also investigated associations between the FLI and parameters of sarcopenia, including DXA-derived appendicular lean mass (ALM) and handgrip strength by dynamometry. Muscle density was measured using pQCT at the radius and tibia. FLI was calculated from BMI, waist circumference, and levels of triglycerides and gamma-glutamyltransferase. There was a pattern of decreasing muscle density across increasing quartiles of FLI. After adjusting for age and lifestyle, mean radial muscle density in Q4 was 2.1% lower than Q1 (p < 0.001) and mean tibial muscle density was 1.8% lower in Q3 and 3.0% lower in Q4, compared to Q1 (p = 0.022 and < 0.001, respectively). After adjusting for age and sedentary lifestyle, participants in the highest FLI quartile were sixfold more likely to have sarcopenia. In conclusion, our results suggest that fat accumulation in the liver co-exists with fat infiltration into skeletal muscle.

Regular Exercise and Weight-Control Behavior Are Protective Factors against Osteoporosis for General Population: A Propensity Score-Matched Analysis from Taiwan Biobank Participants

The rising prevalence of osteoporosis, which can lead to osteoporotic fractures, increases morbidity, mortality, and socioeconomic burden. Multiple factors influencing bone mass have already been identified. The aim of this study was to investigate whether exercise habits and weight-control behaviors can lower the incidence of osteoporosis in the general population. This retrospective study recruited all participants aged 35–70 years who underwent dual-energy X-ray absorptiometry (DXA) from Taiwan Biobank (TWB). The final analysis consisted of 3320 eligible participants divided into two groups; demographic characteristics, prevalence of clinical symptoms, comorbidities, and daily behavior were collected using a self-reported questionnaire. After propensity score matching with a 1:1 ratio, 1107 out of 2214 individuals were classified into the osteoporosis group. Age, body fat rate, body shape, diabetes mellitus, and social status were found to affect the incidence of osteoporosis. Subjects with a habit of regular exercise and weight-control behavior showed decreased odds of osteoporosis. (odds ratio: 0.709 and 0.753, 95% confidence interval: 0.599–0.839 and 0.636–0.890). In the general population, regular exercise or weight-control behavior lowers the incidence of osteoporosis.

High Visceral Fat Area Attenuated the Negative Association between High Body Mass Index and Sarcopenia in Community-Dwelling Older Chinese People

The association between obesity and sarcopenia remains controversial. The present study was conducted to explore the associations among body mass index (BMI), visceral fat area (VFA), and sarcopenia in older people and analyze their potential mechanisms. This cross-sectional study included 861 community-dwelling older Chinese people from three regions of China. BMI, VFA, muscle mass, muscle strength, physical performance, body composition, and metabolic markers were measured. Muscle mass and muscle strength were positively correlated with BMI, but were negatively correlated with VFA. Simple overweight/obesity was negatively associated with sarcopenia (OR = 0.07, 95% CI = 0.03~0.18), and the OR value was lower than combined obesity (OR = 0.16, 95% CI = 0.09~0.28). Fat free mass and total body protein were positively associated with high BMI but negatively associated with high VFA. Furthermore, high VFA was adversely associated with some metabolic risk factors of sarcopenia. Combination of BMI and VFA increased diagnostic efficiency of low muscle mass and sarcopenia. In conclusion, high BMI was negatively associated with sarcopenia, while high VFA attenuated the negative association between high BMI and sarcopenia. The opposite association may partially be attributed to their different associations with body composition and metabolic risk factors of sarcopenia. Therefore, bedsides BMI, VFA and its interaction with BMI should be considered in sarcopenia prevention.

Leptin in bipolar disorder: A systematic review and meta-analysis

Background

Bipolar disorder (BD) is a psychiatric disorder associated with increased rates of obesity and inflammation. Leptin is an adipokine that is mainly produced by the white adipose tissue in response to insulin. It stimulates the immune system, increasing the production of pro-inflammatory cytokines. There is currently uncertainty regarding possible alterations in peripheral leptin levels across the mood states in BD.

Methods

This study comprises a between-group meta-analysis comparing serum and plasma leptin levels in people with BD in mania, depression or euthymia and healthy controls. We conducted a systematic search for all possibly eligible-English and non-English peer-reviewed articles. We calculated the effect size (ES) utilizing Hedges’ adjusted g using random effects.

Results

Eleven studies were included in the meta-analyses, providing data on 1118 participants. Serum and plasma leptin levels were not altered in subjects with BD when compared to healthy controls in mania (g = −0.99, 95% CI −2.43 to 0.43, P = 0.171), in depression (g = 0.17, 95% CI −0.45 to 0.79, P = 0.584), or in euthymia (g = 0.03, 95% CI −0.39 to 0.46, P = 0.882). However, we did observe a stronger association between leptin levels and both age and BMI in patients with BD in euthymia compared to healthy controls, such that the greater the age of the individuals, the greater the difference in leptin levels between BD and controls; and the higher the BMI, the greater the difference in leptin levels between BD and controls.

Conclusions

Our meta-analysis provides evidence that leptin levels are not altered in BD across the mood spectrum compared to healthy controls. The disproportionate increase of leptin levels with increase in BMI in BD speaks in favour of a potential inflammatory role of white adipose tissue in BD and a disproportionate increase of leptin levels with increase in age.

Resistance Training for Older Adults: Position Statement From the National Strength and Conditioning Association

Fragala, MS, Cadore, EL, Dorgo, S, Izquierdo, M, Kraemer, WJ, Peterson, MD, and Ryan, ED. Resistance training for older adults: position statement from the national strength and conditioning association. J Strength Cond Res 33(8): 2019-2052, 2019-Aging, even in the absence of chronic disease, is associated with a variety of biological changes that can contribute to decreases in skeletal muscle mass, strength, and function. Such losses decrease physiologic resilience and increase vulnerability to catastrophic events. As such, strategies for both prevention and treatment are necessary for the health and well-being of older adults. The purpose of this Position Statement is to provide an overview of the current and relevant literature and provide evidence-based recommendations for resistance training for older adults. As presented in this Position Statement, current research has demonstrated that countering muscle disuse through resistance training is a powerful intervention to combat the loss of muscle strength and muscle mass, physiological vulnerability, and their debilitating consequences on physical functioning, mobility, independence, chronic disease management, psychological well-being, quality of life, and healthy life expectancy. This Position Statement provides evidence to support recommendations for successful resistance training in older adults related to 4 parts: (a) program design variables, (b) physiological adaptations, (c) functional benefits, and (d) considerations for frailty, sarcopenia, and other chronic conditions. The goal of this Position Statement is to a) help foster a more unified and holistic approach to resistance training for older adults, b) promote the health and functional benefits of resistance training for older adults, and c) prevent or minimize fears and other barriers to implementation of resistance training programs for older adults.

Poor Physical Function as a Marker of Sarcopenia in Adults with Class II/III Obesity

BACKGROUND

Adults with class II/III obesity [body mass index (in kg/m2) ≥35] may present with a phenotype characterized by low lean mass and excess fat mass, a condition known as sarcopenic obesity (SO). Little is known about the prevalence and relevance of SO in these individuals, primarily due to a lack of relevant diagnostic criteria.

OBJECTIVE

Here, we explored the definition of SO based on physical function as an outcome of interest in adults with class II/III obesity and applied this definition to compare clinical characteristics between SO and non-SO patients.

METHODS

In this cross-sectional analysis, patients' demographic, anthropometric, and biochemical characteristics, as well as comorbidities and physical activity levels, were collected at an obesity specialty clinic prior to any treatment. Body composition was assessed by dual-energy X-ray absorptiometry. Physical function was assessed by self-reported difficulties with activities of daily living (ADLs) from an 11-item questionnaire. Five SO definitions were tested against reported difficulty with ADLs with the use of receiver operating characteristic (ROC) analysis.

RESULTS

A total of 120 subjects (86% women) aged 46 ± 11 y were included. Based on ROC analysis, SO was best defined by an appendicular skeletal mass (ASM)/weight x 100 (%) <19.35% for women and <24.33% for men, resulting in a prevalence of 25% (n = 30, women 22.3%, men 41.2%). SO was significantly associated with older age, higher waist circumference, higher triglycerides, greater use of antihypertensive medications, and lower physical activity.

CONCLUSIONS

In this sample of adults with class II/III obesity, difficulties with ADLs were best associated with measures of ASM in relation to total body weight. Patients identified with SO using this criterion presented with poorer clinical outcomes such as factors of elevated cardiometabolic risk.

Greater Adipose Tissue Distribution and Diminished Spinal Musculoskeletal Density in Adults With Cerebral Palsy

OBJECTIVES

To examine differences in adipose tissue distribution, lumbar vertebral bone mineral density (BMD), and muscle attenuation in adults with and without cerebral palsy (CP), and to determine the associations between morphologic characteristics.

DESIGN

Cross-sectional, retrospective analyses of archived computed tomography scans.

SETTING

Clinical treatment and rehabilitation center.

PARTICIPANTS

Adults (N=352) with CP (age, 38.8±14.4y; body mass, 61.3±17.1kg; Gross Motor Function Classification System levels, I-V) and a matched cohort of neurotypical adults. Of the 41 adults with CP included in the study, 10 were not matchable because of low body masses.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Computed tomography scans were assessed for visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) areas, psoas major area and attenuation in Hounsfield units (Hu), and cortical and trabecular BMDs.

RESULTS

Adults with CP had lower cortical (β=-63.41 Hu, P<.001) and trabecular (β=-42.24 Hu, P<.001) BMDs and psoas major areas (β=-374.51mm(2), P<.001) and attenuation (β=-9.21 Hu, P<.001) after controlling for age, sex, and body mass. Adults with CP had greater VAT (β=3914.81mm(2), P<.001) and SAT (β=4615.68mm(2), P<.001). Muscle attenuation was significantly correlated with trabecular (r=.51, P=.002) and cortical (r=.46, P<.01) BMD, whereas VAT was negatively associated with cortical BMD (β=-.037 Hu/cm(2), r(2)=.13, P=.03).

CONCLUSIONS

Adults with CP had lower BMDs, smaller psoas major area, greater intermuscular adipose tissue, and greater trunk adiposity than neurotypical adults. VAT and cortical BMD were inversely associated.

The role and regulation of osteoclasts in normal bone homeostasis and in response to injury

Bone is a dynamic tissue, with a range of diverse functions, including locomotion, protection of internal organs, and hematopoiesis. Optimum treatment of fractures and/or bone defects requires knowledge of the complex cellular interactions involved with bone healing and remodeling. Emerging data have underscored the importance of osteoclasts in this process, playing a key role both in normal bone turnover and in facilitating bone regeneration. In this review, the authors discuss the basic principles of osteoclast biology, including its cellular origins, its function, and key regulatory mechanisms, in addition to conditions that arise when osteoclast function is altered.

Orchidectomy-induced alterations in volumetric bone density, cortical porosity and strength of femur are attenuated by dietary conjugated linoleic acid in aged guinea pigs

Age-related osteoporosis and sarcopenia are ascribed in part to reductions in anabolic hormones. Dietary conjugated linoleic acid (CLA) improves lean and bone mass, but its impact during androgen deficiency is not known. This study tested if CLA would attenuate the effects of orchidectomy (ORX)-induced losses of bone and lean tissue. Male guinea pigs (n=40; 70-72 weeks), were randomized into four groups: (1) SHAM+Control diet, (2) SHAM+CLA diet, (3) ORX+Control diet, (4) ORX+CLA diet. Baseline blood sampling and dual-energy X-ray absorptiometry (DXA) scans were conducted, followed by surgery 4 days later with the test diets started 7 days after baseline sampling. Serial blood sampling and DXA scans were repeated 2, 4, 8 and 16 weeks on the test diets. Body composition and areal BMD (aBMD) of whole body, lumbar spine, femur and tibia were measured using DXA. At week 16, muscle protein fractional synthesis rate (FSR), volumetric BMD (vBMD), microarchitecture and bone strength were assessed. Body weight declined after SHAM and ORX surgery, with slower recovery in the ORX group. Dietary CLA did not affect weight or lean mass, but attenuated gains in fat mass. Lean mass was stable in SHAM and reduced in ORX by 2 weeks with whole body and femur bone mineral content (BMC) reduced by 4 weeks; CLA did not alter BMC. By week 16 ORX groups had lower free testosterone and myofibrillar FSR, yet higher cortisol, osteocalcin and ionized calcium with no alterations due to CLA. ORX+Control had higher prostaglandin E2 (PGE2) and total alkaline phosphatase compared to SHAM+Control whereas ORX+CLA were not different from SHAM groups. Femur metaphyseal vBMD was reduced in ORX+CTRL with the reduction attenuated by CLA. Femur cortical thickness (Ct.Th.) and biomechanical strength were reduced and cortical porosity (Ct.Po.) elevated by ORX and attenuated by CLA. This androgen deficient model with a sarcopenic-osteoporotic phenotype similar to aging men responded to dietary CLA with significant benefits to femur density and strength.

Android Adiposity and Lack of Moderate and Vigorous Physical Activity Are Associated With Insulin Resistance and Diabetes in Aging Adults

BACKGROUND

Physical inactivity and excess adiposity are thought to be interdependent "lifestyle" factors and thus, many older adults are at exaggerated risk for preventable diseases. The purposes of this study were to determine the degree of discordance between body mass index (BMI) and adiposity among adults older than 50 years, and to determine the extent to which direct measures of adiposity, and objectively measured sedentary behavior (SB) and physical activity (PA) are associated with insulin resistance (IR) or diabetes.

METHODS

A population representative sample of 2,816 individuals, aged 50-85 years, was included from the combined 2003-2006 National Health and Nutrition Examination Survey (NHANES) datasets. BMI, percent body fat (%BF) and android adiposity as determined by dual energy x-ray absorptiometry, objectively measured SB and PA, established markers of cardiometabolic risk, IR, and type 2 diabetes were analyzed.

RESULTS

Approximately 50% of the men and 64% of the women who were normal weight according to BMI had excessive %BF. Adults with the least SB and greatest moderate and vigorous PA exhibited the healthiest cardiometabolic profiles, whereas adults with the greatest SB and lowest activity had highest risk. Greater android adiposity stores were robustly associated with IR or diabetes in all adults, independent of SB and activity. Among men, less moderate-to-vigorous PA was associated with IR or diabetes; whereas among women, less lifestyle moderate activity was associated with IR or diabetes.

CONCLUSIONS

Android adiposity and low moderate and vigorous PA are the strongest predictors of IR or diabetes among aging adults.

Visceral adiposity is negatively associated with bone density and muscle attenuation

BACKGROUND

The storage of adipose tissue in ectopic compartments is a hallmark attribute linking greater body mass index (BMI) with cardiometabolic diseases. Despite ample evidence to confirm that increased visceral adipose tissue (VAT) deposition occurs with obesity, the interrelations between altered fat partitioning and regional muscle and bone quality are less well understood.

OBJECTIVE

We examined the association between adiposity and spinal muscle and bone quality across a large, heterogeneous cohort of adults.

DESIGN

We identified 8833 thoracic or abdominal computed tomography scans from patients in the University of Michigan Health System who were aged 18-64.9 y. We measured trabecular bone densities, cortical bone densities, VAT areas, and subcutaneous adipose tissue (SAT) areas at vertebral levels T7 to L5. Psoas muscle attenuation (an indicator of fat infiltration in muscle) was measured at the L4 level.

RESULTS

Muscle attenuation as well as trabecular and cortical bone densities revealed negative correlations with BMI, SAT, and VAT. The correlation between BMI and psoas attenuation was -0.321, between BMI and the density of cortical bone was -0.250, and between BMI and trabecular bone was -0.143 (all P < 0.001). However, correlations between VAT and lower muscle attenuation were stronger as were those between VAT and lower bone densities. Inverse correlations between VAT and densities of psoas muscle and cortical and trabecular bone were -0.460, -0.407, and -0.434, respectively (P < 0.001). Even after adjustment for age, sex, and BMI, partial correlations between VAT, muscle attenuation, and bone densities remained significant at -0.250, -0.119, and -0.216, respectively (P < 0.001).

CONCLUSIONS

Contrary to previous reports that high body mass is associated with increased bone quality, our data show a significant negative association between BMI and muscle and bone densities, suggesting fat infiltration into these tissues. More importantly, correlations between VAT and decreased bone and muscle densities remained statistically significant even after adjustment for age, sex, and BMI.

Impact of visceral fat on skeletal muscle mass and vice versa in a prospective cohort study: the Korean Sarcopenic Obesity Study (KSOS)

Objectives

Sarcopenia and visceral obesity have been suggested to aggravate each other, resulting in a vicious cycle. However, evidence based on prospective study is very limited. Our purpose was to investigate whether visceral fat promotes a decrease in skeletal muscle mass and vice versa.

Methods

We observed changes in anthropometric and body composition data during a follow-up period of 27.6±2.8 months in 379 Korean men and women (mean age 51.9±14.6 years) from the Korean Sarcopenic Obesity Study (KSOS). Appendicular lean soft tissue (ALST) mass was calculated using dual-energy X-ray absorptiometry, and visceral fat area (VFA) was measured using computed tomography at baseline and follow-up examination.

Results

ALST mass significantly decreased, whereas trunk and total fat mass increased in both men and women despite no significant change in weight and body mass index. In particular, women with visceral obesity at baseline had a greater decrease in ALST mass than those without visceral obesity (P = 0.001). In multiple linear regression analysis, baseline VFA was an independent negative predictor of the changes in ALST after adjusting for confounding factors including age, gender, life style and body composition parameters, insulin resistance, high sensitivity C-reactive protein and vitamin D levels (P = 0.001), whereas the association between baseline ALST mass and changes in VFA was not statistically significant (P = 0.555).

Conclusions

This longitudinal study showed that visceral obesity was associated with future loss of skeletal muscle mass in Korean adults. These results may provide novel insight into sarcopenic obesity in an aging society.

Weight loss and bone mineral density

PURPOSE OF REVIEW

Despite evidence that energy deficit produces multiple physiological and metabolic benefits, clinicians are often reluctant to prescribe weight loss in older individuals or those with low bone mineral density (BMD), fearing BMD will be decreased. Confusion exists concerning the effects that weight loss has on bone health.

RECENT FINDINGS

Bone density is more closely associated with lean mass than total body mass and fat mass. Although rapid or large weight loss is often associated with loss of bone density, slower or smaller weight loss is much less apt to adversely affect BMD, especially when it is accompanied with high intensity resistance and/or impact loading training. Maintenance of calcium and vitamin D intake seems to positively affect BMD during weight loss. Although dual energy X-ray absorptiometry is normally used to evaluate bone density, it may overestimate BMD loss following massive weight loss. Volumetric quantitative computed tomography may be more accurate for tracking bone density changes following large weight loss.

SUMMARY

Moderate weight loss does not necessarily compromise bone health, especially when exercise training is involved. Training strategies that include heavy resistance training and high impact loading that occur with jump training may be especially productive in maintaining, or even increasing bone density with weight loss.

Métodos de análise da composição corporal em adultos obesos

Os métodos de avaliação da composição corporal em obesos têm sido amplamente discutidos, uma vez que nesses indivíduos a avaliação é dificultada devido às limitações dos equipamentos e características dos métodos utilizados. Esta sessão temática tem o objetivo de esclarecer as características, vantagens e limitações dos métodos de avaliação da composição corporal em adultos obesos. A quantificação de gordura corporal e mas-sa livre de gordura, assim como a avaliação da perda de massa muscular e de massa óssea em obesos são temas de grande interesse científico, uma vez que são utilizados para diagnosticar a obesidade osteosarcopênica. A avaliação da composição corporal de obesos pelo modelo de múltiplos compartimentos é padrão-ouro na prática científica. Por outro lado, o método de absorciometria radiológica de feixe duplo é considerado o padrão de referência em pesquisas e na prática clínica. Estudos indicam que a ressonância magnética e a tomografia computadorizada, em alguns casos, são fortemente correlacionadas com a absorciometria radiológica de feixe duplo. Os demais métodos apresentam limitações em avaliar a composição corporal, bem como suas modificações durante a redução ponderal em indivíduos obesos.