Validation of a description of sarcopenic obesity defined as excess adiposity and low lean mass relative to adiposity

Circulating myostatin as a biomarker of muscle mass and strength in individuals with cancer or obesity

BACKGROUND & AIMS

Our study aims to determine whether myostatin (MSTN) is associated with muscle mass and strength in individuals with cancer or obesity, as well as with cancer cachexia (CC) or sarcopenic obesity (SO).

METHODS

The ACTICA study included individuals with CC (n = 70) or without CC (NC, n = 73). The MYDIASECRET study included individuals with obesity evaluated before (T0) and 3 months (T3) after bariatric surgery (n = 62). Body composition was assessed using bioelectrical impedance analysis (BIA). Skeletal muscle mass (SMM) and appendicular SMM (ASMM) were calculated from Janssen's and Sergi's equations, respectively, and expressed as indexes (SMMI and ASMMI). Handgrip strength (HGS) was assessed using a Jamar hand-held dynamometer. MSTN plasma levels were measured using ELISA. Spearman's coefficient was used to correlate MSTN with muscle mass and strength. Receiver operating characteristic (ROC) curve analysis was performed to identify an optimal MSTN cutoff level for the prediction of CC or SO.

RESULTS

In the ACTICA study, muscle mass and strength were lower in CC individuals than in NC individuals (SMMI: 8.0 kg/m2vs 9.0 kg/m2, p = 0.004; ASMMI: 6.2 kg/m2vs 7.2 kg/m2, p < 0.001; HGS: 28 kg vs 38 kg, p < 0.001). MSTN was also lower in CC individuals than in NC individuals (1434 pg/mL vs 2149 pg/mL, p < 0.001). Muscle mass and strength were positively correlated with MSTN (SMMI: R = 0.500, p < 0.001; ASMMI: R = 0.479, p < 0.001; HGS: R = 0.495, p < 0.001). ROC curve analysis showed a MSTN cutoff level of 1548 pg/mL (AUC 0.684, sensitivity 57%, specificity 75%, p < 0.001) for the prediction of CC. In the MYDIASECRET study, muscle mass and strength were reduced at T3 (SMMI: -8%, p < 0.001; ASMMI: -12%, p < 0.001; HGS: -6%, p = 0.005). MSTN was also reduced at T3 (1773 pg/mL vs 2582 pg/mL, p < 0.001). Muscle mass and strength were positively correlated with MSTN at T0 and T3 (SMMI-T0: R = 0.388, p = 0.002; SMMI-T3: R = 0.435, p < 0.001; HGS-T0: R = 0.337, p = 0.007; HGS-T3: R = 0.313, p = 0.013). ROC curve analysis showed a MSTN cutoff level of 4225 pg/mL (AUC 0.835, sensitivity 98%, specificity 100%, p = 0.014) for the prediction of SO at T3.

CONCLUSIONS

MSTN is positively correlated with muscle mass and strength in individuals with cancer or obesity, suggesting its potential use as a biomarker of muscle mass and strength. The ROC curve analysis suggests the potential use of MSTN as a screening tool for CC and SO.

The agreement of low lean mass with obesity using different definitions and its correlation with hyperuricemia

Background

The agreement on the identification of sarcopenic obesity remains elusive, and its association with hyperuricemia remains unestablished. This study sought to evaluate the agreement of low lean mass (LLM) with obesity and its correlation with hyperuricemia.

Methods

A total of 25,252 study participants, comprising 4,597 individuals with hyperuricemia, were obtained from the National Health and Nutrition Examination Survey spanning the years 1999-2006 and 2011-2018. LLM with obesity was characterized by the coexistence of LLM, determined by the ratio of appendicular lean mass to body mass index (BMI), and three categories of obesity including BMI, body fat percentage (BF%), and waist circumference (WC). We employed Cohen's kappa to evaluate the agreement among the different diagnostic criteria and implemented survey multiple logistic regression and stratified analyses to explicate the connection between LLM with obesity and the risk of hyperuricemia.

Results

When defining obesity using BF%, BMI, and WC, the prevalence of LLM with obesity varied from 6.6 to 10.1%, with moderate-to-strong agreement. In the fully adjusted model, individuals with LLM or any of the three types of obesity exhibited notably elevated odds of developing hyperuricemia. Likewise, participants with LLM and obesity had 2.70 (LLM + BMI), 2.44 (LLM + BF%), and 3.12 (LLM + WC) times the risk of hyperuricemia, respectively, compared with healthy individuals. The association between LLM with obesity and hyperuricemia remained stable and significant across different age and sex subgroups.

Conclusion

When employing the three definitions of obesity, the incidence of LLM with obesity was not high, and the diagnostic agreement was relatively good. The participants with LLM and obesity exhibited an increased risk of hyperuricemia.

The causal relationship between sarcopenic obesity factors and benign prostate hyperplasia

Background

Both benign prostatic hyperplasia (BPH) and sarcopenic obesity (SO) are common conditions among older adult/adults males. The prevalent lifestyle associated with SO is a significant risk factor for the development of BPH. Therefore, we investigated the causal relationship between SO factors and BPH.

Method

The instrumental variables for SO factors were selected using the inverse variance-weighted method, which served as the primary approach for Mendelian randomization analysis to assess the causal effect based on summary data derived from genome-wide association studies of BPH.

Result

The increase in BMR (OR = 1.248; 95% CI = (1.087, 1.432); P = 0.002) and ALM (OR = 1.126; 95% CI = (1.032, 1.228); P = 0.008) was found to be associated with an elevated risk of BPH. However, no genetic causality between fat-free mass distribution, muscle mass distribution, and BPH was observed.

Conclusion

Our findings indicate that a genetic causal association between BMR, ALM and BPH. BMR and ALM are risk factors for BPH. The decrease in BMR and ALM signified the onset and progression of SO, thus SO is a protective factor for BPH.

Sex- and reproductive status-specific relationships between body composition and non-alcoholic fatty liver disease

BACKGROUND

Sex and reproductive status differences exist in both non-alcoholic fatty liver disease (NAFLD) and body composition. Our purpose was to investigate the relationship between body composition and the severity of liver steatosis and fibrosis in NAFLD in different sex and reproductive status populations.

METHODS

This cross-sectional study included 880 patients (355 men, 417 pre-menopausal women, 108 post-menopausal women). Liver steatosis and fibrosis and body composition data were measured using FibroScan and a bioelectrical impedance body composition analyzer (BIA), respectively, and the following parameters were obtained: liver stiffness measurement (LSM), controlled attenuation parameter (CAP), waist circumference (WC), body mass index (BMI), percent body fat (PBF), visceral fat area (VFA), appendicular skeletal muscle mass (ASM), appendicular skeletal muscle mass index (ASMI), fat mass (FM), fat free mass (FFM), and FFM to FM ratio (FFM/FM). Multiple ordinal logistic regression (MOLR) was used to analyze the independent correlation between body composition indicators and liver steatosis grade and fibrosis stage in different sex and menopausal status populations.

RESULTS

Men had higher WC, ASM, ASMI, FFM, and FFM/FM than pre- or post-menopausal women, while pre-menopausal women had higher PBF, VFA, and FM than the other two groups (p < 0.001). Besides, men had greater CAP and LSM values (p < 0.001). For MOLR, after adjusting for confounding factors, WC (OR, 1.07; 95% CI, 1.02-1.12; P = 0.011) and FFM/FM (OR, 0.52; 95% CI, 0.31-0.89; P = 0.017) in men and visceral obesity (OR, 4.16; 95% CI, 1.09-15.90; P = 0.037) in post-menopausal women were independently associated with liver steatosis grade. WC and visceral obesity were independently associated with liver fibrosis stage in men (OR, 1.05; 95% CI, 1.01-1.09, P = 0.013; OR, 3.92; 95% CI, 1.97-7.81; P < 0.001, respectively).

CONCLUSIONS

Increased WC and low FFM/FM in men and visceral obesity in post-menopausal women were independent correlates of more severe liver steatosis. In addition, increased WC and visceral obesity were independent correlates of worse liver fibrosis in men. These data support the sex- and reproductive status-specific management of NAFLD.

Normal values for body composition in adults are better represented by continuous reference ranges dependent on age and BMI

BACKGROUND & AIMS

Reference values for body composition parameters like skeletal muscle mass index (SMI) depend on age and BMI. To ensure reference intervals reflect these changes, they have traditionally been separated into groups of young adults based on sex and BMI. However, this static stratification oversimplifies the dynamic and gradual changes of body composition with increasing age and BMI. The aim was therefore to provide continuous reference ranges for body composition parameters.

METHODS

Cross-sectional data of 1958 healthy men and women with an age between 18 and 97 years and a BMI between 17.1 und 45.6 kg/m² were obtained between 2011 and 2019. Multiple regression analyses stratified by sex with age, age² and BMI as independent variables were conducted to predict fat mass index (FMI), visceral adipose tissue (VAT), SMI, appendicular lean soft tissue index (ALSTI) and the ratio between extracellular to total body water (ECW/TBW).

RESULTS

The regression models explained between 61 (VAT in women and ALSTI in men) and 93% of the variance in the respective body composition parameters (FMI in women). Age had only a minor impact (2-16%) whereas BMI substantially increased the explained variance of reference models for FMI, VAT and ALSTI (total explained variance 61-93%). In SMI, age is a major determinant of the explained variance (36% in men and 38% in women) with BMI equally contributing to the explained variance (total explained variance 72% in men and 75% in women). For ECW/TBW-ratio, age nearly completely explained the variance (79% in men and 74% in women) whereas BMI added only 2-3% to the explained variance.

CONCLUSIONS

In conclusion, the derived continuous reference ranges are expected to improve body composition evaluation especially in very overweight and very old persons. Future studies applying these reference equations need to validate these assumptions. STUDY REGISTRATION, CLINICALTRIALS.GOV: NCT01368640, NCT01481285, NCT03779932, NCT04028648.

Adipocytokines and Associations With Abnormal Body Composition in Rheumatoid Arthritis

OBJECTIVE

We determined associations between adipokines and abnormal body composition in patients with rheumatoid arthritis (RA).

METHODS

Combining data from three RA cohorts, whole-body dual-energy absorptiometry measures of appendicular lean mass and fat mass indices were converted to age-, sex-, and race- and ethnicity-specific Z scores. Lean mass relative to fat mass was determined based on prior methods. Independent associations between body composition profiles and circulating levels of adiponectin, leptin, and fibroblast growth factor (FGF)-21 were assessed using linear and logistic regression models adjusting for demographic characteristics and study cohort. We also determined the improvement in the area under the curve (AUC) for prediction of low lean mass when adipokines were added to predictive models that included clinical factors such as demographic characteristics, study, and body mass index (BMI).

RESULTS

Among 419 participants, older age was associated with higher levels of all adipokines, whereas higher C-reactive protein level was associated with lower adiponectin levels and higher FGF-21 levels. Greater fat mass was strongly associated with lower adiponectin levels and higher leptin and FGF-21 levels. Higher levels of adiponectin, leptin, and FGF-21 were independently associated with low lean mass. The addition of adiponectin and leptin levels to regression models improved prediction of low lean mass when combined with demographic characteristics, study, and BMI (AUC 0.75 vs. 0.66).

CONCLUSION

Adipokines are associated with both excess adiposity and low lean mass in patients with RA. Improvements in the prediction of body composition abnormalities suggest that laboratory screening could help identify patients with altered body composition who may be at greater risk of adverse outcomes.

Deciphering the "obesity paradox" in the elderly: A systematic review and meta-analysis of sarcopenic obesity

Aging and obesity are two global concerns in public health. Sarcopenic obesity (SO), defined as the combination of age-related sarcopenia and obesity, has become a pressing issue. This systematic review and meta-analysis summarize the current clinical evidence relevant to SO. PubMed, Embase, and Web of Science were searched, and 106 clinical studies with 167,151 elderlies were included. The estimated prevalence of SO was 9% in both men and women. Obesity was associated with 34% reduced risk of sarcopenia (odds ratio [OR] 0.66, 95% CI 0.48-0.91; p < 0.001). The pooled hazard ratio (HR) of all-cause mortality was 1.51 (95% CI 1.14-2.02; p < 0.001) for people with SO compared with healthy individuals. SO was associated with increased risk of cardiovascular disease and related mortality, metabolic disorders, cognitive impairment, arthritis, functional limitation, and lung diseases (all ORs > 1.0, p < 0.05). The attenuated risk of sarcopenia in elderlies with obesity ("obesity paradox") was dependent on higher muscle mass and strength. Apart from unifying the diagnosis of SO, more research is needed to subphenotype people with obesity and sarcopenia for individualized treatment. Meanwhile, the maintenance of proper body composition of muscle and fat may delay or attenuate the adverse outcomes of aging.

Associations Between Low Serum Urate, Body Composition, and Mortality

OBJECTIVE

Controversy remains as to whether low serum urate or uric acid (UA) levels contribute to adverse outcomes. We evaluated the relation between low serum UA levels and sarcopenia and assessed whether sarcopenia confounds associations between these low levels and mortality.

METHODS

We utilized data from the National Health and Nutrition Examination Survey (1999-2006). Participants with available whole-body dual x-ray absorptiometry body composition measurements and serum UA concentrations were included. Body composition assessments included body mass index (BMI), waist circumference, maximum lifetime BMI, and age-, sex-, and race-specific appendicular lean mass index (ALMI) and fat mass index (FMI) Z scores. We also calculated Z scores for ALMI relative to FMI (ALMIFMI ). We evaluated associations between serum UA levels and body composition using logistic regression and assessed associations between serum UA levels and mortality before and after adjusting for differences in body composition using Cox proportional hazards regression.

RESULTS

Among the 13,979 participants, low serum UA concentrations (<2.5 mg/dl in women, <3.5 mg/dl in men) were associated with low lean mass (ALMI and ALMIFMI Z scores), underweight BMI (<18.5 kg/m2 ), and higher rates of weight loss. The proportion of patients with low ALMI Z scores was 29% in the low serum UA group and 16% in the normal serum UA group (P = 0.001). Low serum UA levels were associated with increased mortality before we adjusted for body composition (hazard ratio 1.61 [95% confidence interval 1.14-2.28]; P = 0.008) but was attenuated and not significant after adjustment for body composition and weight loss (hazard ratio 1.30 [95% confidence interval 0.92-1.85], P = 0.13).

CONCLUSION

Sarcopenia and weight loss are more common among patients with low serum UA concentrations. Differences in body composition may help to explain associations between low levels of serum UA and higher mortality.

The prevalence of low muscle mass associated with obesity in the USA

BACKGROUND

Sarcopenia is defined as age-related low muscle mass and function, and can also describe the loss of muscle mass in certain medical conditions, such as sarcopenic obesity. Sarcopenic obesity describes loss of muscle and function in obese individuals; however, as sarcopenia is an age-related condition and obesity can occur in any age group, a more accurate term is obesity with low lean muscle mass (OLLMM). Given limited data on OLLMM (particularly in those aged < 65 years), the purpose of this study was to estimate the prevalence of OLLMM in adults aged ≥ 20 years in the USA.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) 2017-2018 and 1999-2006 were used. OLLMM was defined as an appendicular lean mass, adjusted for body mass index (BMI), cut-off point < 0.789 for males and < 0.512 for females, measured by dual-energy X-ray absorptiometry (DXA). DXA was only measured in individuals 20-59 years old in NHANES 2017-2018; we therefore utilized logistic regression models to predict OLLMM from NHANES 1999-2006 for those aged ≥ 60 years. The prevalence of OLLMM was estimated overall, and by sex, age, race/ethnicity, and clinical subgroup (high BMI, prediabetes, type 2 diabetes mellitus [T2DM], non-alcoholic fatty liver disease [NAFLD] with fibrosis, or post-bariatric surgery). Prevalence estimates were extrapolated to the USA population using NHANES sampling weights.

RESULTS

We estimated that, during 2017-2018, 28.7 million or 15.9% of the USA population had OLLMM. The prevalence of OLLMM was greater in older individuals (8.1%, aged 20-59 years vs 28.3%, aged ≥ 60 years), highest (66.6%) in Mexican-American females aged ≥ 60 years, and lowest (2.6%) in non-Hispanic Black males aged 20-59 years. There was a higher prevalence of OLLMM in adults with prediabetes (19.7%), T2DM (34.5%), NAFLD with fibrosis (25.4%), or post-bariatric surgery (21.8%), compared with those without each condition.

CONCLUSIONS

Overall, the burden of OLLMM in the USA is substantial, affecting almost 30 million adults. The prevalence of OLLMM increased with age, and among those with prediabetes, T2DM, NAFLD with fibrosis, or post-bariatric surgery. A unified definition of OLLMM will aid diagnosis and treatment strategies.

Low cholesterol is not associated with depression: data from the 2005-2018 National Health and Nutrition Examination Survey

Background

Although high serum cholesterol is widely recognized as a major risk factor for heart disease, the health effects of low cholesterol are less clear. Several studies have found a correlation between low cholesterol and depression, but the results are inconsistent.

Methods

Data from the National Health and Nutrition Examination Survey (NHANES) 2005-2018 were utilized in this cross-sectional study. The analysis of the relationship between cholesterol and depression was performed at three levels: low total cholesterol, low high-density lipoprotein (HDL) cholesterol and low-density lipoprotein (LDL) cholesterol. The inclusion criteria were as follows: (1) people with low (<4.14 mmol/L) or normal (4.14-5.16 mmol/L) total cholesterol for Sample 1; people with low (<1 mmol/L) or normal (≥1 mmol/L) HDL cholesterol levels for Sample 2; and people with low (<1.8 mmol/L) or normal (1.8-3.4 mmol/L) LDL cholesterol levels for Sample 3; and (2) people who completed the Patient Health Questionnaire-9 depression scale. Age, sex, educational level, race, marital status, self-rated health, alcohol status, smoking status, body mass index (BMI), poverty income ratio, physical function, comorbidities, and prescription use were considered potential confounders. The missing data were handled by multiple imputations of chained equations. Logistic regression was used to assess the relationship between low cholesterol and depression.

Results

After controlling for potential confounding factors in the multivariate logistic regression, no association was observed between depression and low total cholesterol (OR=1.0, 95% CI: 0.9-1.2), low LDL cholesterol (OR=1.0, 95% CI: 0.8-1.4), or low HDL cholesterol (OR=0.9, 95% CI: 0.8-1.1). The results stratified by sex also showed no association between low total cholesterol, low LDL cholesterol, low HDL cholesterol and depression in either men or women.

Conclusion

This population-based study did not support the assumption that low cholesterol was related to a higher risk of depression. This information may contribute to the debate on how to manage people with low cholesterol in clinical practice.

The fatter, the better in old age: the current understanding of a difficult relationship

PURPOSE OF REVIEW

Obesity has shown a protective effect on mortality in older adults, also known as the obesity paradox, but there are still controversies about this relationship.

RECENT FINDINGS

Recent studies have shown a J or U-shaped relationship between BMI and mortality, wherein an optimal range is described between 22 and 37 kg/m2 depending on the condition. Many mechanisms can explain this protective effect of higher BMI, fat/muscle mass storage, more aggressive treatment in obese individuals, loss of bone mineral content and selection bias. However, BMI must be used with caution due to its limitations to determine body composition and fat distribution.

SUMMARY

Although BMI is an easy tool to evaluate obesity, its protective effect may be present to certain extend, from normal range to class I obesity (BMI 30-34.9 kg/m2), but then it becomes detrimental. Skeletal muscle mass and muscle function associated with adipose tissue assessment can add valuable information in the risk stratification. Further studies should be performed prospectively, adjust BMI for cofounding variable and consider other elderly subpopulations. To promote healthy ageing, excessive fat mass should be avoided and maintenance or improvement of skeletal muscle mass and muscle function should be stimulated in older adults.

Body composition in individuals with cystic fibrosis

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BMI is used to characterize nutritional status but may not accurately depict body composition in CF.

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DXA and bioelectrical impedance are the most commonly used methods for assessing BC.

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Lower fat-free mass associates with worse pulmonary function and greater CF disease severity.

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Fat-free mass associates with greater bone mineral density in individuals with CF.

Because nutritional status is intimately linked with pulmonary function and survival, nutrition has been at the mainstay of cystic fibrosis (CF) care. Body Mass Index (BMI) is traditionally used to define nutritional status because of the ease with which it can be calculated, but it has a number of limitations including its inability to differentiate fat mass (FM) from lean body mass (LBM), the latter thought to confer health advantage. A number of tools are available to quantify body composition including dual-energy x-ray absorptiometry (DXA), bioelectrical impedance, MRI, CT, air displacement plethysmography, and stable isotopes, and these have been used to varying degrees in studies of CF. In CF, LBM tends to be lower for a given BMI, particularly at lower BMI. In adults, lower fat-free mass (FFM) correlates with greater CF disease severity, lower pulmonary function and higher inflammatory markers. FFM is also positively associated with greater bone mineral density, while greater FM is associated with greater loss of lumbar spine bone mineral density over 2 years. In youth, LBM is positively associated with pulmonary function. The predictive value of body composition for functional and clinical outcomes and the role of improving LBM on these outcomes remain undefined. With improvements in BMI accompanying highly-effective modulator therapy, closer evaluations of body composition may inform risk for more traditional, non-CF adult outcomes in CF.

Association of body composition with risk of overall and site-specific cancers: A population-based prospective cohort study

Although excess adiposity has been linked with various cancers, association between body composition and some cancers remains unclear, like lung and prostate cancers. We investigated associations of body composition with risk of overall cancer and major site-specific cancers in a prospective cohort of 454 079 cancer-free participants from UK-Biobank. Body composition was measured with bioimpedance analysis. We evaluated hazard ratio (HR) and 95% confidence interval (CI) with multivariate Cox linear and nonlinear models in men and women separately. We identified 27 794 cancers over 7.6 years of follow-up. Multivariable adjusted models including fat-free mass (FFM) and fat mass (FM) showed that FFM was positively associated with overall cancer risk in men and women (HR 1.03, 95% CI 1.01-1.04 and 1.07, 1.04-1.10, respectively); while the association between FM and overall cancer disappeared after adjusting for FFM. FFM was associated with higher risks of obesity-related cancers combined, stomach (women only), malignant melanoma, postmenopausal breast, corpus uteri, prostate, kidney (men only), and blood cancers and lower risk of lung cancer. FM was associated with higher risks of obesity-related cancers combined, esophageal, colon, lung (men only), postmenopausal breast (at the lower end of FM range), and corpus uteri cancers and lower risks of rectal, malignant melanoma (women only), prostate and blood cancers. FFM and FM seemed to have different effects on cancer risk, and the effects varied substantially by cancer type, in both direction and size. Higher FM/FFM ratio was also associated with some cancers risk, and might be a useful predictor of cancer risk.

Sarcopenic Obesity in Rheumatoid Arthritis: Prevalence and Impact on Physical Functioning

OBJECTIVE

We determined the prevalence of sarcopenic obesity in patients with rheumatoid arthritis (RA) using multiple methods and assessed associations with physical functioning.

METHODS

This study evaluated data from three RA cohorts. Whole-body dual-energy absorptiometry (DXA) measures of appendicular lean mass index (ALMI, kg/m2) and fat mass index (FMI) were converted to age, sex, and race-specific Z-Scores and categorized using a recently validated method and compared it to a widely-used existing method. The prevalence of body composition abnormalities in RA was compared with two reference populations. In the RA cohorts, associations between body composition and change in the Health Assessment Questionnaire (HAQ) and the Short Physical Performance Battery (SPPB) in follow-up were assessed using linear and logistic regression, adjusting for age, sex, race, and study.

RESULTS

The prevalence of low lean mass and sarcopenic obesity were higher in patients with RA (14.2; 12.6%, respectively) compared with the reference population cohorts (7-10%; 4-4.5%, respectively, all p< 0.05). There was only moderate agreement among methods of sarcopenic obesity categorization (Kappa 0.45). The recently validated method categorized fewer subjects as obese, and many of these were categorized as low lean mass only. Low lean mass, obesity, and sarcopenic obesity were each associated with higher HAQ and lower SPPB at baseline and numerically greater worsening.

CONCLUSION

RA patients had higher rates of low lean mass and sarcopenic obesity than the general population. The recently validated methods characterized body composition changes differently from traditional methods and were more strongly associated with physical function.

Fat mass to fat-free mass ratio and the risk of non-alcoholic fatty liver disease and fibrosis in non-obese and obese individuals

Context

Body composition may explain partially why non-obese individuals still at the risk of developing non-alcoholic fatty liver disease (NAFLD). The ratio of fat mass to fat-free mass (FM/FFM) has been proposed to assess the combined effect of different body compositions.

Objective

We aimed to investigate the associations of FM/FFM ratio with the risk of developing NAFLD and fibrosis and to identify the potential mediators according to obesity status.

Methods

This cohort study comprised 3419 adults age ≥ 40 years and free of NAFLD at baseline. Body composition was measured by bioelectrical impedance analysis. NAFLD was ascertained by ultrasonography and fibrosis was assessed by non-invasive score systems.

Results

For each 1 standard deviation increment in FM/FFM ratio, the odds ratio for the risk of NAFLD was 1.55 (95% confidence interval [CI] 1.23–1.95) in non-obese men, 1.33 (95% CI 1.08–1.65) in obese men, 1.42 (95% CI 1.44–1.67) in non-obese women, and 1.29 (95% CI 1.12–1.50) in obese women. Similar associations were also found between FM/FFM ratio and NAFLD with fibrosis. Mediation analysis showed that insulin resistance, triglycerides, high-density lipoprotein cholesterol, white blood cells, and total cholesterol mediated the association of FM/FFM ratio with NAFLD risk in specific sex and obesity subgroups.

Conclusions

The FM/FFM ratio significantly associated with the NAFLD and fibrosis risk in both non-obese and obese individuals. Different factors may mediate the association between body composition and NAFLD risk according to different obesity status.

Changes in body composition and lipid profile in prostate cancer patients without bone metastases given Degarelix treatment: the BLADE prospective cohort study

BACKGROUND

Luteinizing hormone-releasing hormone (LHRH)-agonists in prostate cancer (PCa) patients induce sarcopenic obesity. The effect of LHRH-antagonist on body composition has never been explored. We evaluated changes in fat (FBM) and lean body mass (LBM) in PCa patients undergoing Degarelix.

METHODS

This is a single-center prospective study, enrolling 29 non-metastatic PCa patients eligible to LHRH-antagonist from 2017 to 2019. All patients received monthly subcutaneous injection of Degarelix for 12 months. Changes in FBM and LBM between baseline and 12-month Degarelix, as measured by dual-energy x-ray absorptiometry, were the co-primary endpoints. Secondary endpoints were changes in serum lipids, glucose profile and follicle-stimulating hormone (FSH). Appendicular lean mass index (ALMI) and ALMI/FBM ratio were assessed as post-hoc analyses. Linear mixed models with random intercept tested for estimated least squared means differences (EMD).

RESULTS

FBM significantly increased after 12 months (EMD +2920.7, +13.8%, p < 0.001), whereas LBM remained stable (EMD -187.1, -0.3%, p = 0.8). No differences occurred in lipid profile. Glycated hemoglobin significantly increased and serum FSH significantly decreased. A significant inverse relationship was found between serum FSH and ALMI/FBM ratio after 12 month (r = -0.44, p = 0.02).

CONCLUSIONS

The BLADE study prospectively evaluated changes in body composition after LHRH-antagonist. LHRH-antagonist therapy is associated to an increased risk of obesity and diabetes, but lean body mass and serum lipids are not affected. This may represent an additional evidence supporting the reduced cardiovascular risk associated with LHRH-antagonist. The role of FSH in influencing sarcopenic obesity in PCa after androgen deprivation deserves to be further explored.

Validation of a description of sarcopenic obesity defined as excess adiposity and low lean mass relative to adiposity

BACKGROUND

This study aims to assess the construct validity of a body composition-defined definition of sarcopenic obesity based on low appendicular lean mass relative to fat mass (ALMIFMI ) and high fat mass index (FMI) and to compare with an alternative definition using appendicular lean mass index (ALMI) and percent body fat (%BF).

METHODS

This is a secondary analysis of two cohort studies: the National Health and Examination Survey (NHANES) and the Health, Aging, and Body Composition study (Health ABC). Sarcopenic obesity was defined as low ALMIFMI combined with high FMI and was compared with a widely used definition based on ALMI and %BF cut-points. Body composition Z-scores, self-reported disability, physical functioning, and incident disability were compared across body composition categories using linear and logistic regression and Cox proportional hazards models.

RESULTS

Among 14, 850 participants from NHANES, patients with sarcopenic obesity defined by low ALMIFMI and high FMI (ALMIFMI -FMI) had above-average FMI Z-scores [mean (standard deviation): 1.00 (0.72)]. In contrast, those with sarcopenic obesity based on low ALMI and high %BF (ALMI-%BF) had below-average FMI Z-scores. A similar pattern was observed for 2846 participants from Health ABC. Participants with sarcopenic obesity based on ALMIFMI -FMI had a greater number of disabilities, worse physical function, and a greater risk of incident disability compared with those defined based on ALMI-%BF.

CONCLUSIONS

Body composition-defined measures of sarcopenic obesity defined as excess adiposity and lower-than-expected ALMI relative to FMI are associated with functional deficits and incident disability and overcome the limitations of using %BF in estimating obesity in this context.