Advanced body composition assessment: from body mass index to body composition profiling

Lower-limb injury in elite Australian football: A narrative review of kinanthropometric and physical risk factors

OBJECTIVE

This review aims to provide a succinct and critical analysis of the current physical and mechanical demands of elite Australian football while examining lower-limb injury and the associated physical and kinanthropometric risk factors.

METHODS

MEDLINE, PubMed, Web of Science and SPORTSDiscus electronic databases were searched for studies that investigated the playing demands, injury trends, and physical and kinanthropometric injury risk factors of elite Australian football. Articles from similar team sports including soccer and rugby (union and league) were also included.

RESULTS

While the physical demands of elite AF have steadied over the past decade, injury rates continue to rise with more than two-thirds of all injuries affecting the lower-limbs. Body composition and musculoskeletal morphological assessments are regularly adopted in many sporting settings with current research suggesting high and low body mass are both associated with heightened injury risk. However, more extensive investigations are required to determine whether the proportions of muscle and fat are linked. Repeated assessment of musculoskeletal morphology may also provide further insight into stress fracture rates.

CONCLUSIONS

While kinanthropometric and physical attributes are highly valued within elite sporting environments, establishing a deeper connection with injury may provide practitioners with more insight into current injury trends.

Beneficial effects of a combination of Clostridium cochlearium and Lactobacillus acidophilus on body weight gain, insulin sensitivity, and gut microbiota in high-fat diet-induced obese mice

OBJECTIVES

Species Lactobacillus acidophilus and butyrate producer Clostridium cochlearium have been shown to have potential antiobesity effects. The aim of this study was to show that the combination of C. cochlearium and L. acidophilus (CC-LA) has beneficial effects on body weight control and glucose homeostasis in high-fat diet-induced obese (DIO) mice.

METHODS

In this study, thirty-six 6-wk-old male C57BL/6 mice were randomly assigned to three groups of 12 mice each. The experimental group (CC-LA) was administered with CC-LA mixture and fed ad libitum with a high-fat diet. High-fat diet (HF) control and low-fat diet (LF) control groups were treated with the same dose of sterile water as the CC-LA group.

RESULTS

After 17 wk of dietary intervention, the CC-LA group showed 17% less body weight gain than the HF group did (P < 0.01). The CC-LA group also showed significantly reduced incremental area under the curve of oral glucose tolerance test and homeostatic model assessment for insulin resistance compared with the HF group. The results from 16S rRNA sequencing analysis of gut microbiota showed that the CC-LA administration led to overall increased α-diversity indices, and a significant microbial separation from the HF group. The ratio of Firmicutes to Bacteroidetes (F/B) was reduced from 3.30 in the HF group to 1.94 in the CC-LA group. The relative abundances of certain obesity-related taxa were also decreased by CC-LA administration.

CONCLUSION

The present study provided evidence that the CC-LA combination reduced obesity and improved glucose metabolism in high-fat diet-treated DIO mice, potentially mediated by the modulation of gut microbiota.

Pixel-wise body composition prediction with a multi-task conditional generative adversarial network

The analysis of human body composition plays a critical role in health management and disease prevention. However, current medical technologies to accurately assess body composition such as dual energy X-ray absorptiometry, computed tomography, and magnetic resonance imaging have the disadvantages of prohibitive cost or ionizing radiation. Recently, body shape based techniques using body scanners and depth cameras, have brought new opportunities for improving body composition estimation by intelligently analyzing body shape descriptors. In this paper, we present a multi-task deep neural network method utilizing a conditional generative adversarial network to predict the pixel level body composition using only 3D body surfaces. The proposed method can predict 2D subcutaneous and visceral fat maps in a single network with a high accuracy. We further introduce an interpreted patch discriminator which optimizes the texture accuracy of the 2D fat maps. The validity and effectiveness of our new method are demonstrated experimentally on TCIA and LiTS datasets. Our proposed approach outperforms competitive methods by at least 41.3% for the whole body fat percentage, 33.1% for the subcutaneous and visceral fat percentage, and 4.1% for the regional fat predictions.

Dietary fructose intake is correlated with fat distribution in the Newfoundland population

OBJECTIVE

Increased dietary fructose intake is associated with elevated body weight and body mass index. Few studies are available regarding the relationship between fat distribution and dietary fructose intake. The aim of this study was to investigate the association between dietary fructose intake and fat distribution in adults in a large Newfoundland cohort.

METHODS

We analyzed 2298 adults from CODING (Complex Diseases in the New found land Population: Environment and Genetics) study. Intake of dietary fructose was evaluated from the Willett food frequency questionnaire. Fat distribution was estimated by dual-energy x-ray absorptiometry. Partial correlation analysis was used to determine the correlations of dietary fructose intake with fat distribution adjusted for major confounding factors.

RESULTS

Daily dietary fructose intake was negatively associated with arm fat in postmenopausal women (r = -0.080, P < 0.05), but positively associated with arm fat in premenopausal women after adjusting for age, total calorie intake, and physical activity levels (r = 0.079, P < 0.05). Dietary fructose intake was negatively correlated with both arm fat (r = -0.131, P < 0.05) and visceral fat (r = -0.124 measured in mass, r = -0.124 measured in volume respectively; P < 0.05) in men <45 y of age, not in men ≥45 y.

CONCLUSION

This study demonstrated that dietary fructose intake is significantly correlated with arm fat in both women and men, and visceral fat in men in the Newfoundland free-living population. The correlations are sex- and menopause-status dependent.

Validation of skeletal muscle mass estimation equations in active young adults: A preliminary study

We analyzed the validity of the estimation equations for skeletal muscle mass (SMM) using mass of appendicular lean soft tissue (ALST), evaluated by dual-energy X-ray absorptiometry (DXA), in healthy young males undergoing training, and compared it with the results obtained using whole-body magnetic resonance imaging (MRI). We hypothesized that a novel variable, that is, trunk and trunk-to-appendicular ratio of lean soft tissues (trunk/ALST), would be useful in reducing estimation errors in athletes or physically active participants. We analyzed the data of 30 participants (mean age 19.9 ± 1.8 years). SMM was measured using whole-body MRI, while mass of trunk and ALST was assessed using DXA. Three previously utilized estimation equations were retrieved from the literature and used for comparison. The estimated SMM values using previous equations highly correlated with measured SMM, which was determined by MRI, but the mean estimated SMM values were significantly lower than the measured-SMM values. Stepwise regression analysis revealed that mass of ALST, trunk/ALST ratio, and percent body fat were significant predictors of SMM and were incorporated as the new suggested variables. This equation accounted for 90.3% of the variance in SMM. While the previous equations' estimated SMM correlated with measured-SMM in participants with trunk/ALST ratios ≤1.05, they underestimated SMMs in those with trunk/ALST ratios >1.05. The present study confirms that the previously used equations underestimate the actual SMM, particularly in participants with high trunk/ALST ratios (>1.05). The current equation may be used in healthy and active young males, including athletes, as a preliminary tool.

Catch-Up Growth in Children Born Small for Gestational Age Related to Body Composition and Metabolic Risk at Six Years of Age in the UK

OBJECTIVES

To determine differences in body composition and glucose metabolism according to childhood growth outcomes in a population-based sample of children born small for gestational age (SGA).

METHODS

A single-centre study of 259 children born SGA identified through hospital records and contacted when aged 4-7 years. Questionnaire data on pre/perinatal history and growth parameters during childhood was collected from the parents, and in a subgroup of 150 children face-to-face assessments were performed, including anthropometric parameters, lean and fat mass, blood pressure, fasting glucose, and C-peptide.

RESULTS

Based on the questionnaires, few children had formal clinic follow-up of growth, but 7% of the cohort showed a height and weight of <-2SDS during childhood, and only 2 children met the criteria for growth hormone therapy. Out of the 150 children assessed at a mean age of 6.1 ± 0.8 years, 122 (81%) showed a catch-up growth in weight. Compared to those without weight catch-up, these children had a higher fat mass index (3.13 ± 1.36 vs. 2.56 ± 0.91 kg/m2, p = 0.04), trunk-to-limb fat mass ratio (0.63 ± 0.14 vs. 0.56 ± 0.08, p = 0.002), systolic blood pressure SDS (0.09 ± 0.71 vs. -0.32 ± 0.63, p = 0.008), fasting glucose (4.5 ± 0.5 vs. 4.3 ± 0.5 mmol/L, p = 0.03), and C-peptide (306 ± 116 vs. 256 ± 112 pmol/L, p = 0.08). Among children with weight catch-up growth, those with less height gain had a lower limb lean mass index (4.25 ± 0.48 vs. 4.48 ± 0.56 kg/m2, p = 0.02) and fat mass index (1.57 ± 0.59 vs. 1.83 ± 0.77 kg/m2, p = 0.04).

CONCLUSIONS

Within this population-based sample of SGA children, catch-up growth in weight was associated with higher abdominal fat mass, blood pressure and glycemia; furthermore, in these children, less height gain was associated with reduced limb lean and fat mass.

Anthropometric features in predicting insulin resistance among non-menopausal Indonesian adult females

INTRODUCTION

The prevalence of obesity is increasing worldwide in high, low, and middle-income countries such as Indonesia. Obesity rate is higher in females in Indonesia. Obesity has important contribution in the occurrence of insulin resistance (IR) and type 2 diabetes mellitus. Several anthropometric measurements such as waist circumference (WC), body mass index (BMI), body mass (BM), total body fat percentage (Fat%) and visceral fat (VF) are related to IR. This study aimed to investigate which of those measurements could be used as a better predictor of IR in non-menopausal Indonesian adult females.

METHODS

Total of 80 non-menopausal Indonesian adult females ranging from 21 to 40 years were recruited in this study. Insulin resistance was measured by using Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) equation. Subjects with HOMA-IR index >75th percentile with cut-off 2.74 were defined as IR. Waist circumference, BMI and BM were measured, while TF and VF were measured by bioelectrical impedance analysis (BIA).

RESULTS

HOMA-IR had significant correlation with WC (r = 0.563, p < 0.001), BMI (r = 0.537, p < 0.001), BM (r = 0.515, p < 0.001), VF (r = 0.515, p < 0.001), Fat% (r = 0.490, p < 0.001). The area under curve of VF (0.809), BMI (0.807), WC (0.805), and BM (0.799) are slightly larger than and Fat% (0.766).

CONCLUSION

Insulin resistance had strong correlation with all anthropometric measurements, but the correlation was less significant with Fat%.

How Does Fat Mass Change in the First Year After Bariatric Surgery? A Systemic Review and Meta-Analysis

This systematic review and meta-analysis investigated the time-course effect of different type of bariatric surgeries (BS) up to 1 year post-surgery on fat mass (FM) and body fat percentage (BFP) in patients with morbid obesity. We searched PubMed, Scopus, EMBASE, ISI web of science, and Cochrane databases from October 2002 until May 2020 with no restriction in the English language, to find studies examining the effect of BS on FM (kg) and BFP (%) in morbid obese patients. Meta-analysis of 103 studies carried out on data of 18,166 and 14,575 morbid obese patients following BS, showed that BS was associated with a substantial decrease in FM and BFP, respectively, in 1 month (- 8.17 kg [95% CI - 9.07, - 7.27] and - 1.51% [95% CI - 2.56, - 0.46]), 3 months (- 15.75 [95% CI - 17.49, - 14.0] and - 4.90 [95% CI - 5.97, - 3.83]), 6 months (- 22.51 [95% CI - 23.93, - 21.09] and - 8.56% [95% CI - 9.63, - 7.49]), and 12 months (- 29.69 [95% CI - 31.3, - 28.09] and - 13.49% [95% CI - 14.52, - 12.40]) after the surgery. In conclusion, BS was associated with sustained declines in FM and BFP, from 1 to 12 months, with no indication of plateau phase post-surgery post-operatively. The present study emphasizes that post-bariatric care should have more focus on FM loss during 1-year post-surgery to identify the patients at risk for fat loss plateau.

Body composition and risk of heart failure: protocol for a systematic review and meta-analysis

INTRODUCTION

Although there is strong evidence of an association between general adiposity and incidence of heart failure, previous systematic reviews and meta-analyses have not reliably assessed the association of heart failure risk with other aspects of body composition (such as body fat distribution or lean mass), or between body composition and risk of heart failure subtypes. We aim to conduct a systematic review and meta-analysis of prospective studies to address these uncertainties, and inform efforts to prevent and treat heart failure.

METHODS AND ANALYSIS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Protocols statement was used as a template for this protocol. A systematic search of Medline, Embase and Global Health from database inception to present will be conducted to identify prospective studies reporting on the associations between major measures of body composition (body mass index, waist circumference, waist-hip ratio, total body fat, visceral adiposity tissue and lean mass) and risk of heart failure. Article screening and selection will be performed by two reviewers independently, and disagreements will be adjudicated by consensus or by a third reviewer. Data from eligible articles will be extracted, and article quality will be assessed using the Newcastle-Ottawa Scale. Relative risks (and 95% CIs) will be pooled in a fixed effect meta-analysis, if there is no prohibitive heterogeneity of studies as assessed using the Cochrane Q statistic and I2 statistic. Subgroup analyses will be by age, sex, ethnicity and heart failure subtypes. Publication bias in the meta-analysis will be assessed using Egger's test and funnel plots.

ETHICS AND DISSEMINATION

This work is secondary analyses on published data and ethical approval is not required. We plan to publish results in an open-access peer-reviewed journal, present it at international and national conferences, and share the findings on social media.

PROSPERO REGISTRATION NUMBER

CRD42020224584.

Design and Development of a Temperature-Compensated Body Mass Index Measuring System

The measurement of body mass index (BMI) is an important indicator of preliminary assessment of human health. A higher BMI value increases the risk factor for critical diseases, e.g., high blood pressure (hypertension), cardiovascular disease, gallbladder disease, type 2 diabetes, etc. Obesity also increases the risk factor of COVID-19 in patients. BMI, the ratio of mass (in kilogram) to the square of height (in meter), is an estimation of an individual's physique. It depends upon the adult’s height and mass and is intended to evaluate the tissue mass. In this article, we have described the design and developmental aspects of a temperature-compensated BMI measuring system. The developed BMI measuring system is comprised of an ultrasonic sensor for height measurement, strain gauge-based load cell for precise and accurate mass measurement, a temperature sensor to eliminate the effect of temperature, and a microcontroller with related electronics, software, and display system. The developed BMI system is capable to measure mass precisely in the range (0–200) kg with a resolution of 0.01 kg, and height in the range of (0–4) m with resolution of 0.01 m. The expanded uncertainty in height measurement is estimated as 2.8 mm. The BMI value is determined with the help of these parameters and displayed with precision of 0.01. The novelty of the developed system is temperature compensation in the height measurement using an ultrasonic sensor, which has been introduced first time. Also, system is improved for its highly precise and accurate measurements at a comparatively lower cost than the commercially available existing systems.

Comparison of Simplified Creatinine Index and Systemic Inflammatory Markers for Nutritional Evaluation of Hemodialysis Patients

Protein-energy wasting (PEW) is associated with adverse outcomes in hemodialysis patients. This study compares the simplified creatinine index (SCI) and circulating inflammatory markers as nutritional screening tools for hemodialysis patients. Maintenance hemodialysis patients (230 total patients, 34.8% women, 64.0 ± 14.3 years old) from a tertiary medical center were assessed for demographic data, body composition analysis, biochemistry tests, and circulating inflammatory biomarkers. The SCI was calculated using Canaud’s formula. Reduced fat-free mass index (FFMI), a surrogate of lean body mass, was identified according to the European Society for Clinical Nutrition and Metabolism guidelines. Nutritional status was assessed by the geriatric nutritional risk index (GNRI) and International Society of Renal Nutrition and Metabolism (ISRNM) criteria. Multivariate logistic regression revealed independent risk factors for low FFMI and malnutrition. Of the patients, 47.4% had low FFMI. Patients with a reduction in FFMI tended to be older females with lower body mass index, SCI, and GNRI scores but significantly higher levels of interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and IL-8. SCI was found to be an independent predictor for reduced FFMI (OR 0.57, 95% CI 0.40–0.81) and presence of PEW according to ISRNM criteria (OR 0.38, 95% CI 0.21–0.68). Although a positive association between systemic inflammatory markers and low FFMI was observed, this association disappeared in multivariate analysis. Moreover, the inflammatory markers examined in this study were not associated with malnutrition after adjusting for potential confounders. Compared with markers of systemic inflammation, SCI achieved better performance in assessing the nutritional status of hemodialysis patients.

Sex Differences in Adaptations in Muscle Strength and Size Following Resistance Training in Older Adults: A Systematic Review and Meta-analysis

BACKGROUND

Reductions in muscle size and strength occur with aging. These changes can be mitigated by participation in resistance training. At present, it is unknown if sex contributes to differences in adaptation to resistance training in older adults.

OBJECTIVE

The aim of this systematic review was to determine if sex differences are apparent in adaptations to resistance training in older adults.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

Web of Science; Science Direct; SPORTDiscus; CINAHL; and MEDLINE were searched from inception to June 2020.

ELIGIBILITY CRITERIA

Studies where males and females older than 50 years of age performed identical resistance training interventions and had outcome measures of muscle strength or size.

RESULTS

We initially screened 5337 studies. 30 studies (with 41 comparison groups) were included in our review (1410 participants; 651 males, 759 females). Mean study quality was 14.7/29 on a modified Downs and Black checklist, considered moderate quality. Females gained more relative lower-body strength than males (g = - 0.21 [95% CI - 0.33, - 0.10], p = 0.0003) but there were no differences in relative change for upper-body strength (g = - 0.29 [95% CI - 0.62, 0.04], p = 0.08) or relative muscle size (g = 0.10 [95% CI - 0.04, 0.23], p = 0.16). Males gained more absolute upper-body strength (g = 0.48 [95% CI 0.09, 0.88], p = 0.016), absolute lower-body strength (g = 0.33 [95% CI 0.19, 0.47], p < 0.0001), and absolute muscle size (g = 0.45 [95% CI 0.23, 0.66], p < 0.0001).

CONCLUSION

Our results indicate that sex differences in adaptations to resistance training are apparent in older adults. However, it is evident that the interpretation of sex-dependent adaptations to resistance training is heavily influenced by the presentation of the results in either an absolute or relative context.

STUDY REGISTRATION

Open Science Framework (osf.io/afn3y/).

Weight regulation in menopause

IMPORTANCE AND OBJECTIVE

Obesity is a chronic disease of epidemic proportions that continues to affect millions of Americans each year. Postmenopausal women are particularly affected by obesity and have higher rates of severe obesity when compared with their male counterparts. The prevalence of obesity in this population is linked to increased morbidity and mortality and promotes the development and progression of numerous obesity-related health conditions. This review examines the epidemiology, pathophysiology, clinical assessment, and treatment of postmenopausal women with obesity.

METHODS

We have reviewed relevant and up-to-date literature in the MEDLINE database to represent the current understanding of obesity and its effects in this patient population. Articles published between the years 2000 and 2020 were selected for review to represent the most up-to-date evidence on the topic. Search terms used in the PubMed search included women, obesity, menopause, aging, mid-age women, metabolism, weight gain, treatment of obesity, weight loss, bariatric surgery, weight loss medications, diet, physical activity, and behavior modification.

DISCUSSION AND CONCLUSION

Obesity is a complex, chronic, relapsing disease that requires comprehensive assessment and treatment. Obesity is linked to hormonal, lifestyle, and environmental changes that occur during the menopausal transition, and it increases the risk for cardiometabolic disease. The utilization of appropriate clinical evaluation methods to identify obesity in postmenopausal women, and the implementation of effective lifestyle, pharmacotherapeutic, and surgical interventions, have the propensity to reduce the deleterious effects of obesity in this population.

Association of Body Composition with Type 2 Diabetes: A Retrospective Chart Review Study

This study analyzed the body composition of individuals with type 2 diabetes (T2DM). In this retrospective chart review study, body composition was measured through multifrequency bioelectrical impedance analysis (InBody 770). Body composition assessments were conducted in individuals with T2DM, who were aged ≥18 years. The parameters included body mass index (BMI), body fat mass (BFM), fat-free mass (FFM), visceral fat area, percent body fat (PBF), appendicular skeletal muscle mass (ASM), and skeletal muscle index (SMI). One-way ANOVA and independent t-tests were used to calculate differences in body composition distribution by age and sex. A total of 2404 participants were recruited. The prevalence of overall low muscle mass and sarcopenic obesity was 28.0% and 18.7%, respectively, which increased with age. The overall prevalence of obesity when PBF was used was 71.5%, which was higher than that when BMI was applied (32.4%). The normal BMI group exhibited a prevalence of low muscle mass of 55.6% and sarcopenic obesity of 34.8%. For both men and women, bodyweight, BFM, FFM, ASM, and SMI all decreased with age. The prevalence of low muscle mass and sarcopenic obesity was high in older adults and people with normal BMI. Using BMI to assess obesity and determine insufficient muscle mass underestimates the prevalence of obesity and neglects the problems of sarcopenia and high body fat in people with normal BMI.

Association of Oophorectomy and Fat and Lean Body Mass: Evidence from a Population-Based Sample of U.S. Women

BACKGROUND

Bilateral oophorectomy during a nonmalignant hysterectomy is frequently performed for ovarian cancer prevention in premenopausal women. Oophorectomy before menopause leads to an abrupt decline in ovarian hormones that could adversely affect body composition. We examined the relationship between oophorectomy and whole-body composition.

METHODS

Our study population included cancer-free women 35 to 70 years old from the 1999-2006 National Health and Nutrition Examination Survey, a representative sample of the U.S.

POPULATION

A total of 4,209 women with dual-energy x-ray absorptiometry scans were identified, including 445 with hysterectomy, 552 with hysterectomy and oophorectomy, and 3,212 with no surgery. Linear regression was used to estimate the difference in total and regional (trunk, arms, and legs) fat and lean body mass by surgery status.

RESULTS

In multivariable models, hysterectomy with and without oophorectomy was associated with higher total fat mass [mean percent difference (β); β_oophorectomy: 1.61%; 95% confidence interval (CI), 1.00-2.28; β_hysterectomy: 0.88%; 95% CI, 0.12-1.58] and lower total lean mass [β_oophorectomy: -1.48%; 95% CI, -2.67, -1.15; β_hysterectomy: -0.87%; 95% CI, -1.50, -0.24) compared with no surgery. Results were stronger in women with a normal body mass index (BMI) and those <45 years at surgery. All body regions were significantly affected for women with oophorectomy, whereas only the trunk was affected for women with hysterectomy alone.

CONCLUSIONS

Hysterectomy with oophorectomy, particularly in young women, may be associated with systemic changes in fat and lean body mass irrespective of BMI.

IMPACT

Our results support prospective evaluation of body composition in women undergoing hysterectomy with oophorectomy at a young age.

Body composition by computed tomography vs. dual energy x-ray absorptiometry: Long-term prediction of all-cause mortality in the Health ABC cohort

BACKGROUND

Body composition assessment by computed tomography (CT) predicts health outcomes in diverse populations. However, its performance in predicting mortality has not been directly compared to dual-energy-X-ray-absorptiometry (DXA). Additionally, the association between different body compartments and mortality, acknowledging the compositional nature of human body, is not well-studied. Compositional Data Analysis, that is applied to multivariate proportion-type dataset, may help to account for the inter-relationships of body compartments by constructing log-ratios of components. Here, we determined the associations of baseline CT-based measures of mid-thigh cross-sectional areas vs. DXA measures of body composition with all-cause mortality in Health ABC cohort, using both traditional (individual body compartments) and Compositional Data Analysis (using ratios of body compartments) approaches.

METHODS

The Health ABC study assessed body composition in 2911 older adults in 1996-97. We investigated the individual and ratios of (by Compositional Analysis) body compartments assessed by DXA (lean, fat, and bone-mass) and CT (muscle, subcutaneous fat area, intermuscular fat (IMF), and bone) on mortality, using Cox proportional hazard models.

RESULTS

Lower baseline muscle area by CT (HRmen=0.56 [95%CI: 0.48-0.67], HRwomen=0.60 [0.48-0.74]), fat-mass by DXA (HRmen=0.48 [0.24-0.95]) were predictors of mortality in traditional Cox-regression analysis. Consistently, Compositional Data Analysis revealed that lower muscle area vs. IMF, muscle area vs. bone area, and lower fat-mass vs. lean-mass were associated with higher mortality in both sexes.

CONCLUSION

Both CT measure of muscle area and DXA fat-mass (either individually or relative to other body compartments) were strong predictors of mortality in both sexes in a community research setting.

The association of body fat composition with risk of breast, endometrial, ovarian and colorectal cancers among normal weight participants in the UK Biobank

BACKGROUND

The association between body fat composition and risk of cancer in normal weight individuals (body mass index (BMI) 18.5-24.9 kg/m2) is unclear.

METHODS

We examined the association of measures of adiposity with risk of incident cancers of the breast (postmenopausal), endometrium, ovary and colon/rectum among 149,928 normal weight individuals (40-70 years) who were enrolled in the UK Biobank cohort between 2006 and 2010.

RESULTS

All of the body fat measures were positively associated with invasive postmenopausal breast cancer risk (hazard ratios (HR) for the uppermost quintile (Q5) versus the lowest quintile (Q1) ranged from 1.32 (95% CI: 1.09-1.60) for waist circumference (WC) to 1.56 (1.28-1.90) for BMI). Trunk fat mass index (HRQ5 vs Q1: 1.72, 95% CI: 1.02-2.89) and WC (HRQ5 vs Q1: 1.65, 95% CI: 1.01-2.70)) were positively associated with risk of endometrial cancer. Among males, trunk fat:trunk fat free mass ratio, trunk fat:leg fat mass ratio and (HRQ5 vs Q1: 1.63, 95% CI: 1.02-2.60; 1.92, 1.20-3.07 and 1.68, 1.05-2.66, respectively) were positively associated with colon cancer risk. None of the body fat measures was associated with risk of ovarian cancer or colorectal cancer in women.

CONCLUSION

The findings of this study suggest that the current normal weight category based on BMI includes individuals who are at increased risk of some obesity-related cancers.

Antimicrobial Dosing in Specific Populations and Novel Clinical Methodologies: Obesity

Obesity and its related comorbidities can negatively influence the outcomes of certain infectious diseases. Specific dosing recommendations are often lacking in the product label for patients with obesity that leads to unclear guidance in practice. Higher rates of therapeutic failure have been reported with some fixed dose antibiotics and pragmatic approaches to dose modification are limited for orally administered agents. For i.v. antimicrobials dosed on weight, alternate body size descriptors (ABSDs) have been used to reduce the risk of overdosing. These ABSDs are mathematical transformations of height and weight that represent fat-free weight and follow the same principles as body surface area (BSA)-based dosing of cancer chemotherapy. However, ABSDs are rarely studied in pivotal phase III studies and so can risk the underdosing of antimicrobials in patients with obesity when incorrectly applied in the real-world setting. Specific case examples are presented to highlight these risks. Although general principles may be considered by clinicians, a universal approach to dose modification in obesity is unlikely. Studies that can better distinguish human body phenotypes may help reduce our reliance on height and weight to define dosing. Simple and complex technologies exist to quantify individual body composition that could improve upon our current approach. Early evidence suggests that body composition parameters repurposed from medical imaging data may improve upon height and weight as covariates of drug clearance and distribution. Clinical trials that can integrate human body phenotyping may help us identify new approaches to optimal dose selection of antimicrobials in patients with obesity.

Effect of Whole-Body Vibration Training on Muscle Activation for Individuals with Knee Osteoarthritis

Whole-body vibration (WBV) training may improve the strength of lower extremity muscles in patients with knee osteoarthritis (KOA), but the inconsistency in vibration parameters leads to differences in findings. This cross-sectional study is aimed at observing the effects of different vibration frequencies and knee flexion angles on the activation of lower extremity muscles in patients with KOA. Enrolled participants received WBV training at 0, 30, and 60° knee flexion angles with vibration frequencies of 0, 5, 10, and 20 Hz. Activation rates for vastus medialis, vastus lateralis, rectus femoris, biceps femoris, and semitendinosus in different combinations were collected through surface electromyography. The effects of frequency and angle on muscle activation rate were quantified by repeated measures ANOVA. Individual and synergistic effects of frequency and angle were also analysed. Twenty-six participants with KOA were included. Muscle activation increased with the vibration frequency in 0–20 Hz range and with knee flexion angle in 0–60° range. WBV training at 20 Hz was the most effective for knee muscle activation, and static squatting at 60° was the most suitable for WBV training. Therefore, WBV training can increase the activation rate of knee flexor and extensor muscles in patients with KOA, and the most efficient combination was 20 Hz vibration frequency and 60° knee flexion. When applying WBV to patients with KOA, individual differences and rehabilitation purposes should be considered in selecting vibration parameters and knee angle to effectively increase neuromuscular activity.

Visceral Adiposity Elevates the Risk of Critical Condition in COVID-19: A Systematic Review and Meta-Analysis

OBJECTIVE

A higher BMI has become acknowledged as one of the important risk factors for developing critical condition in coronavirus disease 2019 (COVID-19). In addition to BMI, body composition, and particularly visceral adiposity, might be an even more accurate measure to stratify patients. Therefore, the aim of this study was to evaluate the association between the distributions of computed-tomography-quantified fat mass and critical condition of patients with COVID-19.

METHODS

A systematic search was conducted in five databases for studies published until November 17, 2020. In the meta-analysis, pooled mean difference (standardized mean difference [SMD]) of visceral fat area (VFA; in square centimeters) was calculated between patients in the intensive care unit and those in general ward and between patients with the requirement for invasive mechanical ventilation (IMV) and those without the IMV requirement.

RESULTS

The quantitative synthesis revealed that patients requiring intensive care had higher VFA values (SMD = 0.46, 95% CI: 0.20-0.71, P < 0.001) compared with patients on the general ward. Similarly, patients requiring IMV had higher VFA values (SMD = 0.38, 95% CI: 0.05-0.71, P = 0.026) compared with patients without the IMV requirement.

CONCLUSIONS

VFA values were found to be significantly higher in patients with critical condition. Therefore, abdominal adiposity seems to be a risk factor in COVID-19, and patients with central obesity might need special attention.

Obesity among postmenopausal women: what is the best anthropometric index to assess adiposity and success of weight-loss intervention?

OBJECTIVES

First, to establish the respective ability of body mass index (BMI), waist circumference (WC), and relative fat mass index (RFM), to estimate body fat (BF%) measured by DXA (DXA-BF%) and correctly identify postmenopausal women living with obesity (BF% > 35). Second, to identify the best indicator of successful weight-loss intervention in postmenopausal women living with obesity.

METHODS

A total of 277 women (age: 59.8 ± 5.3 y; BF%: 43.4 ± 5.3) from five weight-loss studies with complete data for anthropometric measurements [BMI = weight/height (kg/m2); WC (cm)] and BF% were pooled together. Statistical performance indicators were determined to assess ability of RFM [64-(20 × height/waist circumference) + (12 × sex)], BMI and WC to estimate BF% before and after weight-loss intervention and to correctly identify postmenopausal women living with obesity.

RESULTS

Compared with RFM (r = 0.51; r2 = 0.27; RMSE = 4.4%; Lin's CCC = 0.46) and WC (r = 0.49; r2 = 0.25; RMSE = 4.8%; Lin's CCC = 0.41), BMI (r = 0.73; r2 = 0.52; RMSE = 3.7%; Lin's CCC = 0.71) was the best anthropometric index to estimate DXA-BF% and correctly identify postmenopausal women living with obesity (sensitivity + specificity: BMI = 193; RFM = 152; WC = 158), with lower misclassification error, before weight-loss intervention. After weight-loss, the change in BMI was strongly correlated with change in DXA-BF%, indicating that the BMI is the best indicator of success weight-loss intervention.

CONCLUSION

In the absence of more objective measures of adiposity, BMI is a suitable proxy measure for BF% in postmenopausal women, for whom a lifestyle intervention is relevant. Furthermore, BMI can be used as an indicator to assess success of weight-loss intervention in this subpopulation.

Genetically predicted physical activity levels are associated with lower colorectal cancer risk: a Mendelian randomisation study

BACKGROUND

We conducted a Mendelian randomisation (MR) study to investigate whether physical activity (PA) causes a reduction of colorectal cancer risk and to understand the contributions of effects mediated through changes in body fat.

METHODS

Common genetic variants associated with self-reported moderate-to-vigorous PA (MVPA), acceleration vector magnitude PA (AMPA) and sedentary time were used as instrumental variables. To control for confounding effects of obesity, we included instrumental variables for body mass index (BMI), body fat percentage, waist circumference and arm, trunk and leg fat ratios. We analysed the effect of these instrumental variables in a colorectal cancer genome-wide association study comprising 31,197 cases and 61,770 controls of European ancestry by applying two-sample and multivariable MR study designs.

RESULTS

We found decreased colorectal cancer risk for genetically represented measures of MVPA and AMPA that were additional to effects mediated through genetic measures of obesity. Odds ratio and 95% confidence interval (CI) per standard deviation increase in MVPA and AMPA was 0.56 (0.31, 1.01) and 0.60 (0.41, 0.88), respectively. No association has been found between sedentary time and colorectal cancer risk. The proportion of effect mediated through BMI was 2% (95% CI: 0, 14) and 32% (95% CI: 12, 46) for MVPA and AMPA, respectively.

CONCLUSION

These findings provide strong evidence to reinforce public health measures on preventing colorectal cancer that promote PA at a population level regardless of body fatness.

Comparison of anthropometric indices for predicting the risk of metabolic syndrome in older adults

Background. The prevalence of obesity and metabolic syndrome (MetS) is increasing, worldwide. Using a simple, efficient and reliable tool for predicting MetS is an essential approach in preventive health programs. The aim of this study was to compare the different anthropometric indices in predicting metabolic syndrome in older adults.Methods. This cross-sectional study is a part of the Amirkola Health and Ageing cohort Project (2011-2016). Of total, 1,488 older people aged 60-92 years were entered to the study. Medical and personal information of participants were collected by a questionnaire. After measuring the height, weight, waist circumference, hip circumference and neck circumference, body mass index, waist to hip ratio, waist to height ratio, abdominal volume index and conicity index were calculated. Independent t-test, chi-square and ROC curve were used to analyze the data.Results. Based on ATPIII-2005 diagnostic criteria, the prevalence of metabolic syndrome was 71.57%.The prevalence in female was higher than male. All of examined anthropometric indices, except neck circumference (p = 0.10), showed a significant difference in people with MetS compared to the individuals without metabolic syndrome (p<0.001). Waist to height ratio showed the largest area under the curve for predicting MetS (0.786; 95% CI: 0.76-0.81) followed by BMI (0.746; 95% CI: 0.71-0.77), AVI (0.745; 95% CI: 0.71-0.77), and waist circumference (0.743; 95% CI: 0.71-0.77).Conclusion. Waist to height ratio was the best predictor of MetS in older adults.

Evaluation of SUVlean consistency in FDG and PSMA PET/MR with Dixon-, James-, and Janma-based lean body mass correction

PURPOSE

To systematically evaluate the consistency of various standardized uptake value (SUV) lean body mass (LBM) normalization methods in a clinical positron emission tomography/magnetic resonance imaging (PET/MR) setting.

METHODS

SUV of brain, liver, prostate, parotid, blood, and muscle were measured in 90 18F-FDG and 28 18F-PSMA PET/MR scans and corrected for LBM using the James, Janma (short for Janmahasatian), and Dixon approaches. The prospective study was performed from December 2018 to August 2020 at Shanghai East Hospital. Forty dual energy X-ray absorptiometry (DXA) measurements of non-fat mass were used as the reference standard. Agreement between different LBM methods was assessed by linear regression and Bland-Altman statistics. SUV's dependency on BMI was evaluated by means of linear regression and Pearson correlation.

RESULTS

Compared to DXA, the Dixon approach presented the least bias in LBM/weight% than James and Janma models (bias 0.4±7.3%, - 8.0±9.4%, and - 3.3±8.3% respectively). SUV normalized by body weight (SUVbw) was positively correlated with body mass index (BMI) for both FDG (e.g., liver: r = 0.45, p < 0.001) and PSMA scans (r = 0.20, p = 0.31), while SUV normalized by lean body mass (SUVlean) revealed a decreased dependency on BMI (r = 0.22, 0.08, 0.14, p = 0.04, 0.46, 0.18 for Dixon, James, and Janma models, respectively). The liver SUVbw of obese/overweight patients was significantly larger (p < 0.001) than that of normal patients, whereas the bias was mostly eliminated in SUVlean. One-way ANOVA showed significant difference (p < 0.001) between SUVlean in major organs measured using Dixon method vs James and Janma models.

CONCLUSION

Significant systematic variation was found using different approaches to calculate SUVlean. A consistent correction method should be applied for serial PET/MR scans. The Dixon method provides the most accurate measure of LBM, yielding the least bias of all approaches when compared to DXA.

Prevalence and Nonpharmacological Interventions for Sarcopenia among Cirrhotic Patients

Sarcopenia is the most common feature of hepatic cirrhosis characterized by progressive loss of muscle mass and function and increases permanently the mortality and morbidity rates among those patients. The incidence of sarcopenia in cirrhotic patients ranged 40-70% associating with impaired quality of life and augmented rates of infection. Based on these issues, this review is aimed at determining the prevalence and main causes of sarcopenia among cirrhotic patients and recognizing the recent diagnostic and physical treatment modalities that prevent risk factors for sarcopenia in those patients. No ideal modality is currently demonstrated for diagnosing sarcopenia in hepatic diseases, particularly cirrhosis; however, recent studies reported different diagnostic modalities for muscle function in different individuals including handgrip strength, skeletal muscle index, six-min walk test, liver frailty index, short physical performance battery, and radiological assessments for quadriceps and psoas muscles. Exercise training and therapeutic nutrition are strongly recommended for controlling sarcopenia in cirrhotic patients. The exercise program is designed and carried out on a frequent basis within an extensive scheduled time aimed at improving functional performance, aerobic capacity, and healthy conditions. Finally, a combination of exercise training and therapeutic nutrition is powerfully recommended to control sarcopenia in cirrhosis.

Dataset for the estimation of a new body fat measurement method

Due to the increasing prevalence of obesity and its negative consequences worldwide on public health, body composition analysis is a central pillar to assess the nutritional status. Scientists could use datasets to develop a new body fat measurement formula. Using bioelectrical impedance analysis, we analyzed the total body composition of 345 patients (234 men and 111 women) aged between 18 and 60 years residing in the metropolitan area of Barranquilla, Colombia. They have the potential for predictive formula analysis enhancing the cooperation among scientists. Due to the obesity pandemic, new datasets from other populations are needed to develop a body fat basic mathematical equation formula that could be used worldwide to determine the prevalence of overweight and obesity in a specific population group predisposed to develop metabolic syndrome or death, secondary to high cardiovascular risk.

Lean regional muscle volume estimates using explanatory bioelectrical models in healthy subjects and patients with muscle wasting

BACKGROUND

The availability of non-invasive, accessible, and reliable methods for estimating regional skeletal muscle volume is paramount in conditions involving primary and/or secondary muscle wasting. This work aimed at (i) optimizing serial bioelectrical impedance analysis (S_BIA ) by computing a conductivity constant based on quantitative magnetic resonance imaging (MRI) data and (ii) investigating the potential of S_BIA for estimating lean regional thigh muscle volume in patients with severe muscle disorders.

METHODS

Twenty healthy participants with variable body mass index and 20 patients with idiopathic inflammatory myopathies underwent quantitative MRI. Anatomical images and fat fraction maps were acquired in thighs. After manual muscle segmentation, lean thigh muscle volume (lV_MRI ) was computed. Subsequently, multifrequency (50 to 350 kHz) serial resistance profiles were acquired between current skin electrodes (i.e. ankle and hand) and voltage electrodes placed on the anterior thigh. In vivo values of the muscle electrical conductivity constant were computed using data from S_BIA and MRI gathered in the right thigh of 10 healthy participants. Lean muscle volume (lV_BIA ) was derived from S_BIA measurements using this newly computed constant. Between-day reproducibility of lV_BIA was studied in six healthy participants.

RESULTS

Electrical conductivity constant values ranged from 0.82 S/m at 50 kHz to 1.16 S/m at 350 kHz. The absolute percentage difference between lV_BIA and lV_MRI was greater at frequencies >270 kHz (P < 0.0001). The standard error of measurement and the intra-class correlation coefficient for lV_BIA computed from measurements performed at 155 kHz (i.e. frequency with minimal difference) against lV_MRI were 6.1% and 0.95 in healthy participants and 9.4% and 0.93 in patients, respectively. Between-day reproducibility of lV_BIA was as follows: standard error of measurement = 4.6% (95% confidence interval [3.2, 7.8] %), intra-class correlation coefficient = 0.98 (95% confidence interval [0.95, 0.99]).

CONCLUSIONS

These findings demonstrate a strong agreement of lean muscle volume estimated using S_BIA against quantitative MRI in humans, including in patients with severe muscle wasting and fatty degeneration. S_BIA shows promises for non-invasive, fast, and accessible estimation and follow-up of lean regional skeletal muscle volume for transversal and longitudinal studies.

The effect of body mass index on hippocampal morphology and memory performance in late childhood and adolescence

Childhood obesity is associated with negative physiological and cognitive health outcomes. The hippocampus is a diverse subcortical structure involved in learned feeding behaviors and energy regulation, and research has shown that the hippocampus is vulnerable to the effects of excess adiposity. Previous studies have demonstrated reduced hippocampal volume in overweight and obese children; however, it is unclear if certain subregions are selectively affected. The purpose of this study was to determine how excess body weight influences regional hippocampal surface morphology and memory performance in a large cross-sectional cohort of 588 children and adolescents between 8.33 and 19.92 years of age using body mass index expressed as a percentage of the 95th percentile cutoff (%BMIp95). We demonstrate %BMIp95 is associated with reduced radial thickness in the superior anterior region of the left hippocampus, and this relationship is predominantly driven by children younger than 14 years. We also found %BMIp95 was associated with worse performance on a spatial episodic memory task and this relationship was partially mediated by the radial thickness of the significant shape cluster. These results demonstrate the differential influence of excess body weight on regional hippocampal structure and hippocampal-dependent behavior in children and adolescents.

Body Composition is Associated With Islet Function After Pancreatectomy and Islet Autotransplantation for Pancreatitis

CONTEXT

Body composition in total pancreatectomy with islet autotransplantation (TPIAT) has never been studied.

OBJECTIVE

Determine whether presurgical body composition is associated with islet function and insulin sensitivity after TPIAT.

METHODS

In 88 adults undergoing TPIAT (median age 41.0 years, IQR 32.8-48.0), beta-cell function and insulin sensitivity were assessed using mixed meal tolerance test and frequent sample intravenous glucose tolerance test before surgery and 12 and 18 months afterward. Body composition was measured by dual x-ray absorptiometry. Analyses used linear and logistic regression.

RESULTS

Before surgery, 8 individuals (9.1%) were underweight, 40 (45.5%) normal weight, 20 (22.7%) overweight, and 20 (22.7%) obese. Overweight/obese patients had higher area under the curve C-peptide and lower insulin sensitivity index. Baseline body weight was positively associated with first-phase insulin secretion (AIRg) at 12 months (average 38.5 [SE 17.1] mU/L/min higher per extra kg; P = 0.03) and 18 months (38.3 [18.5]; P = 0.04), while baseline lean mass was inversely associated with AIRg at 12 months (-0.05 [0.02] per extra kg; P = 0.01) and 18 months (-0.05 [0.02]; P = 0.03). Percent gynoid fat was inversely associated with disposition index at 18 months (-206.0 [97.2] per extra percent; P = 0.04). Percent body fat and percent gynoid fat were associated with glucose effectiveness index at 18 months (1.9 × 10-3 [0.9 × 10-3] per extra percent; P = 0.04 and -1.96 × 10-3 [0.8 × 10-3]; P = 0.02, respectively). Insulin independence was not significantly associated with body weight or composition.

CONCLUSIONS

Half of these chronic pancreatitis patients were overweight/obese; underweight was uncommon. Preoperative body weight and composition were associated with islet function but not insulin independence after TPIAT.

Towards Personalized Management of Sarcopenia in COPD

The awareness of the presence and consequences of sarcopenia has significantly increased over the past decade. Sarcopenia is defined as gradual loss of muscle mass and strength and ultimately loss of physical performance associated with aging and chronic disease. The prevalence of sarcopenia is higher in chronic obstructive pulmonary disease (COPD) compared to age-matched controls. Current literature suggests that next to physical inactivity, COPD-specific alterations in physiological processes contribute to accelerated development of sarcopenia. Sarcopenia in COPD can be assessed according to current guidelines, but during physical performance testing, ventilatory limitation should be considered. Treatment of muscle impairment can halt or even reverse sarcopenia, despite respiratory impairment. Exercise training and protein supplementation are currently at the basis of sarcopenia treatment. Furthermore, effective current and new interventions targeting the pulmonary system (eg, smoking cessation, bronchodilators and lung volume reduction surgery) may also facilitate muscle maintenance. Better understanding of disease-specific pathophysiological mechanisms involved in the accelerated development of sarcopenia in COPD will provide new leads to refine nutritional, exercise and physical activity interventions and develop pharmacological co-interventions.

Seeking an Initial-Weight-Independent Metric in a Mediterranean Cohort of Gastric Bypass Patients: the %AWL Revisited

BACKGROUND

Most relative weight-loss metrics follow the formula "Weight loss(%) = 100 · (Initial BMI - Final BMI) / (Initial BMI-a)," where a is the reference point that defines the metric. The percentage of total weight loss (%TWL, a = 0) and percentage of excess weight loss (%EWL, a = 25) are influenced by a patient's initial weight. Recently, the percentage of alterable weight loss metric (%AWL, a = 13) has been reported to produce initial-weight-independent outcomes.

OBJECTIVES

This study aimed to replicate the methodology used for %AWL determination in a Mediterranean cohort of bariatric patients.

SETTINGS

Multicenter study in 10 large hospitals in Spain.

METHODS

Two large prospective databases were retrospectively searched for all primary laparoscopic gastric bypass patients with 2 years of follow-up. Outcomes at nadir were expressed and analyzed with 26 different metrics (a from 0 to 25), looking for the metric whose outcomes produced (1) the lowest coefficient of variation, (2) no differences between initially lighter and heavier patients, and (3) no correlation with patients' initial BMI.

RESULTS

A cohort of 1793 patients was stratified into 4 gender-age groups: younger women (YW, n = 733), older women (OW, n = 674), younger men (YM, n = 197), and older men (OM, n = 189). The calculations suggested an optimal reference point of 18 kg/m², defining a new metric (percentage of Mediterranean alterable weight loss, %MAWL). When %TWL, %EWL, %AWL, and %MAWL were tested on the whole sample, only %MAWL produced initial-weight-independent results.

CONCLUSIONS

In our Mediterranean cohort of patients, a reference point of 18 (and not 13) yielded initial-weight-independent outcomes.

Adiposity in Survivors of Cancer in Childhood: How is it Measured and Why Does it Matter?

Survival of cancer in childhood is increasingly common with modern therapeutic protocols but leads frequently to adverse long-term impacts on health, including metabolic and cardiovascular disease. Changes in body composition, especially an increase in fat mass and a decrease in muscle mass, are found early in patients with pediatric cancer, persist long after treatment has been completed and seem to contribute to the development of chronic disease. This review details the effects of such changes in body composition and reviews the underlying pathophysiology of the development of sarcopenic obesity and its adverse metabolic impact. The authors discuss the particular challenges in identifying obesity accurately in survivors of pediatric cancer using available measurement techniques, given that common measures, such as body mass index, do not distinguish between muscle and adipose tissue or assess their distribution. The authors highlight the importance of a harmonized approach to the assessment of body composition in pediatric cancer survivors and early identification of risk using "gold-standard" measurements. This will improve our understanding of the significance of adiposity and sarcopenia in this population, help identify thresholds predictive of metabolic risk, and ultimately prevent or ameliorate the long-term metabolic and cardiovascular impacts on health experienced by survivors of cancer in childhood.

Imaging-Based Body Fat Distribution in Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis

BACKGROUND

Women with polycystic ovary syndrome (PCOS) are generally considered to be central obese and at higher risks of metabolic disturbances. Imaging methods are the golden standards for detecting body fat distribution. However, evidence based on magnetic resonance imaging (MRI) and computed tomography (CT) is conflicting. This study systematically reviewed the imaging-based body fat distribution in PCOS patients and quantitatively evaluated the difference in body fat distribution between PCOS and BMI-matched controls.

METHODS

PUBMED, EMBASE, and Web of Science were searched up to December 2019, and studies quantitatively compared body fat distribution by MRI, CT, ultrasound, or X-ray absorptiometry (DXA) between women with PCOS and their BMI-matched controls were included. Two researchers independently reviewed the articles, extract data and evaluated the study quality based on Newcastle-Ottawa Scale (NOS).

RESULTS

47 studies were included in systematic review and 39 were eligible for meta-analysis. Compared to BMI-matched controls, higher accumulations of visceral fat (SMD 0.41; 95%CI: 0.23-0.59), abdominal subcutaneous fat (SMD 0.31; 95%CI: 0.20-0.41), total body fat (SMD 0.19; 95% CI: 0.06-0.32), trunk fat (SMD 0.47; 95% CI: 0.17-0.77), and android fat (SMD 0. 36; 95% CI: 0.06-0.66) were identified in PCOS group. However, no significant difference was identified in all the above outcomes in subgroups only including studies using golden standards MRI or CT to evaluate body fat distribution (SMD 0.19; 95%CI: -0.04-0.41 for visceral fat; SMD 0.15; 95%CI: -0.01-0.31 for abdominal subcutaneous fat). Moreover, meta-regression and subgroup analyses showed that young and non-obese patients were more likely to accumulate android fat.

CONCLUSIONS

PCOS women seem to have abdominal fat accumulation when compared with BMI-matched controls. However, MRI- and CT- assessed fat distribution was similar between PCOS and controls, suggesting central obesity may be independent of PCOS. These findings will help us reappraise the relationship between PCOS and abnormal fat deposition and develop specialized lifestyle interventions for PCOS patients.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, identifier CRD42018102983.

Assessment of muscle and fat mass in type 2 diabetes patients by dual-energy X-ray absorptiometry

OBJECTIVES

The aim of this study was to assess the quantitative composition of muscle and adipose tissue in type 2 diabetes mellitus (T2DM) patients on the basis of dual-energy X-ray absorptiometry for the diagnosis of obesity and sarcopenia.

METHODS

Dual-energy X-ray absorptiometry was administered to 50 patients with T2DM. Evaluation of the composition of muscle and adipose tissue was performed.

RESULTS

The median of Appendicular Lean Mass Index (ALMI) in the general group was 8.04 [7.32; 8.97]. In general, there was a decrease in the appendicular muscle mass with increasing age. According to the results of T-score ALMI and Z-score ALMI, we did not identify patients with sarcopenia. However, the calculation of the T- and Z-criteria, adjusted for fat mass, led to a significant decrease of these parameters and in 98.0% it was possible to identify patients who meet the criteria of sarcopenia.

CONCLUSION

We did not detect patients with sarcopenia on the basis of ALMI, T-ALMI. After revision of these criteria for fat mass, almost all patients started to meet the criteria of sarcopenia (98.0%).

Fat compartments in patients with depression: A meta-analysis

INTRODUCTION

Depressive disorders are a common illness worldwide. Major depression is known as a significant predictor of the metabolic syndrome. However, the effects of depression on adipose tissue compartments are controversial. This meta-analysis aimed to evaluate the state of research on the relationship between patients with depression and adipose tissue compartments as compared to nondepressed individuals.

METHODS

The PubMed database was searched for human studies that measured adipose tissue compartments such as visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and/or organ-specific adipose tissue measurements using dual-energy X-ray absorptiometry, magnetic resonance imaging or computed tomography scan and reported the means and a measure of variance separately for depressed individuals and healthy controls. Twelve articles were identified, including a total of 1,141 depressed and 2,545 nondepressed individuals.

RESULTS

Major depressive disorder and self-reported depressive symptoms were associated with elevated visceral adipose tissue and elevated subcutaneous adipose tissue. Subanalyses for gender, age, method of adipose tissue measurement, and method of depression assessment showed elevated visceral adipose in depressed individuals. The results could be replicated when focussing on studies controlling for body mass index (BMI). Regarding other adipose tissue compartments, meta-analysis could not be carried out due to lack of studies.

CONCLUSIONS

Depression is associated with enlarged visceral and subcutaneous adipose tissue. Further, especially longitudinal, research is needed to identify the mechanism through which depressive disorders contribute to visceral adiposity.

Reference charts for body composition parameters by dual-energy X-ray absorptiometry in European children and adolescents aged 6 to 18 years-Results from the Austrian LEAD (Lung, hEart, sociAl, boDy) cohort

BACKGROUND

DXA is a widely used technique to assess body composition. Reference values based on a large general population cohort of European children and adolescents were missing. The aim of this study was to provide age- and sex-specific reference percentiles of body composition parameters for European children and adolescents and to compare them to the American NHANES cohort. Additionally, exponents accounting best for height biases were analysed.

METHODS

DXA scans of 1573 participants, aged 6 to 18 years, recruited from 2011 to 2019 by the Austrian LEAD study, a representative population-based cohort, have been used to create reference charts using the LMS model.

RESULTS

Reference charts displaying percentile curves and the corresponding reference values are provided. Fat mass parameters were higher in females, while lean mass parameters were higher in males. Compared to the NHANES cohort medians of FMI and LMI were always lower. For FMI, BMI, LMI and ALMI the best fitting exponent were 2.5, 3, 3 and 3.5 respectively CONCLUSIONS: The present study provides reference charts for children and adolescents aged 6 to 18 years, for body composition parameters assessed by DXA. The charts enable comparison to a European general-population cohort and indicate that reference populations should be chosen with caution.

A Pilot Study Examining Body Composition Classification Differences Between Body Mass Index and Bioelectrical Impedance Analysis in Children With High Levels of Physical Activity

Background: Body mass index (BMI) is frequently labeled as "flawed" in assessing obesity since it cannot differentiate between muscle and fat leading to misclassifications of healthy individuals. Bioelectrical impedance analysis (BIA) may be a more accurate indicator of obesity since it can distinguish the difference between muscle and fat in children. This pilot study investigated discrepancies between BMI and BIA body composition classifications in children with high levels of physical activity. Methods: Participants were selected from three elementary schools (N = 380, K = 76, 1st = 64, 2nd = 62, 3rd = 61, 4th = 83, and 5th = 34) receiving 60 min of outdoor, unstructured play daily. BIA scales were used to collect each child's body fat percentage and BMI score, then those numbers were categorized by BIA and BMI normative values as either underweight, healthy, overweight, or obese. Results: Overall, 26% of the students were classified differently when using the normative classifications for BMI and BIA, with the largest discrepancy found in the overweight category at 38%. Similar inconsistencies were found when students were divided as younger (42%) vs older students (36%), and males (40%) vs. females (35%). Conclusions: This pilot study demonstrated that there is a significant difference in how BMI and BIA discriminate between the different body composition categories. BIA consistently shows to be a more accurate tool in assessing obesity rates in children since it directly measures body fat.

Harnessing Muscle-Liver Crosstalk to Treat Nonalcoholic Steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) has reached epidemic proportions, affecting an estimated one-quarter of the world's adult population. Multiple organ systems have been implicated in the pathophysiology of NAFLD; however, the role of skeletal muscle has until recently been largely overlooked. A growing body of evidence places skeletal muscle-via its impact on insulin resistance and systemic inflammation-and the muscle-liver axis at the center of the NAFLD pathogenic cascade. Population-based studies suggest that sarcopenia is an effect-modifier across the NAFLD spectrum in that it is tightly linked to an increased risk of non-alcoholic fatty liver, non-alcoholic steatohepatitis (NASH), and advanced liver fibrosis, all independent of obesity and insulin resistance. Longitudinal studies suggest that increases in skeletal muscle mass over time may both reduce the incidence of NAFLD and improve preexisting NAFLD. Adverse muscle composition, comprising both low muscle volume and high muscle fat infiltration (myosteatosis), is highly prevalent in patients with NAFLD. The risk of functional disability conferred by low muscle volume in NAFLD is further exacerbated by the presence of myosteatosis, which is twice as common in NAFLD as in other chronic liver diseases. Crosstalk between muscle and liver is influenced by several factors, including obesity, physical inactivity, ectopic fat deposition, oxidative stress, and proinflammatory mediators. In this perspective review, we discuss key pathophysiological processes driving sarcopenia in NAFLD: anabolic resistance, insulin resistance, metabolic inflexibility and systemic inflammation. Interventions that modify muscle quantity (mass), muscle quality (fat), and physical function by simultaneously engaging multiple targets and pathways implicated in muscle-liver crosstalk may be required to address the multifactorial pathogenesis of NAFLD/NASH and provide effective and durable therapies.

Diagnostic Central Obesity Indexes Cut - Off Point Values Determined with Dual-Energy X-Ray Absorptiometry in Cushing's and Obese Women

AIM

The aim of this study was to develop quantiative criteria for defining visceral obesity and to establish dual-energy X-ray absorptiometric (DXA) diagnostic cut-off points (CP) for normal and abnormal values of the central obesity indexes (COI) that best differentiate extreme visceral obesity in Cushing's syndrome (CS) from non CS obese and non obese women.

MATERIAL AND METHODS

COI1-4 values calculated as a ratio of android to gynoid tissue mass, fat mass and their % were determined in 4 groups, each consisting of 18 women: 1st group of CS, 2nd group of obese women (O1) not different according to their age and BMI from CS, 3rd group of obese women (O2) with BMI of 35 ± 1.2 kg and 4th group of non obese healthy women (C) with normal BMI. Diagnostic accuracy (DG) of CP values of COI1m-4m indexes of abdominal obesity and CP values of COI1n-4n indexes of normal body fat distribution (BFD) was determined.

RESULTS

COI1-4 indexes values were highly significantly different among the 4 examined groups and were significantly highest in CS patients and lowest in group C (p < 0.0001). COI1m-4m CP values differentiated extreme visceral, abdominal obesity in CS with highest DG as well as COI1n-4n CP values differentiated normal BFD in group C. COI1m CP of 0.55 best differentiated CS from O1 for DG of 100%. COI2n of 0.38 best differentiated C from CS and O2 for highest DG of 100% compared to O1 because of the significantly higher BMI and COI1n-4n values in O2 that were associated with more pronounced abdominal obesity and highly significantly positive correlation with BMI.

CONCLUSIONS

DXA cut-off point values of indexes COI1m-4m and COI1n-4n were established as diagnostic indexes and criteria useful in discovering extreme abdominal and normal BFD. COI1m CP value of 0.55 was discovered as a diagnostic criterion of extreme abdominal obesity and COI2n of 0.38 as a diagnostic criterion of normal BFD that excluded abdominal obesity. The other indexes COI1m-4m and COI1n-4n CP values had also high DG in discovering abdominal and normal body fat distribution.

Is the Urine Cannabinoid Level Measured via a Commercial Point-of-Care Semiquantitative Immunoassay a Cannabis Withdrawal Syndrome Severity Predictor?

Background: For cannabis-dependent subjects, the relationship between cannabis withdrawal syndrome (CWS) severity and the urine cannabinoid concentrations are unclear; we investigated this using a commercial point-of-care (POC) enzyme immunoassay detecting 11-nor-9-carboxy-Delta-9-tetrahydrocannabinol (THC-COOH). Methods: Observational study of 78 adult chronic cannabis-dependent subjects assessed over a 24-day inpatient detoxification treatment, with 13 serial measurement days. Repeated Measures Correlation and Multilevel Linear Models were employed. Results: Absolute urinary THC-COOH levels significantly correlated with Marijuana Withdrawal Checklist (MWC) scores across the entire study duration (r = 0.248; p < 0.001). Correlation between serial creatinine-adjusted THC-COOH ratios and serial MWC scores emerged as significant only in the sample with higher MWC scores (>11 points) at admission (n = 21; r = 0.247; p = 0.002). The aforementioned significant relationships have persisted when replacing the absolute THC-COOH-levels with the (relative) day-to-day change in urinary THC-COOH levels. MWC scores were significantly correlated with the Clinical Global Impression-Severity (CGI-S; r = 0.812; p < 0.001). Females showed a significantly slower decline in urine THC-COOH levels and prolonged CWS course characterized by substantial illness severity (per CGI-S), occurring in nearly 30% of cases. Conclusion: Urine cannabinoid levels (THC-COOH) determined by POC assay significantly predicted CWS severity (moderate correlation), guiding detoxification treatment duration. In patients with MWC > 11 points upon admission, creatinine-adjusted THC-COOH ratios also significantly predicted CWS severity-again with moderate effect size. Females showed prolonged urinary THC-COOH elimination and cannabis withdrawal.

New Multisite Bioelectrical Impedance Device Compared to Hydrostatic Weighing and Skinfold Body Fat Methods

The purpose of this study was to compare the Skulpt Chisel™ to seven-site skinfold (SKF) and hydrostatic weighing (HW) body fat percentage (%BF) estimates. Twenty-six participants (aged 24 ± 4 years; BMI 23.1 ± 3.5 kg·m^-2) were assessed. Significant differences in %BF estimates were found for all methodological pairings; p < 0.05. The SKF method underestimated %BF compared to HW (-2.52 ± 3.42 %BF). The Skulpt Chisel™ overestimated %BF compared to both HW (3.38 ± 6.10 %BF) and SKF (5.90 ± 5.26 %BF). Limits of agreement comparing HW to Skulpt Chisel™ indicated a difference between 95% confidence interval bounds (Upper bound: 5.84 %BF, Lower bound 0.92 %BF) and for HW to SKF (Upper bound: -1.14 %BF, Lower bound: -3.91 %BF). Regression analysis showed no significant bias for any methodological pairing; (p > 0.05). In conclusion, the Skulpt Chisel™ method should be used with caution when evaluating %BF of adults with similar demographics reported in this study.

Safety and pharmacokinetics of bimagrumab in healthy older and obese adults with body composition changes in the older cohort

BACKGROUND

Bimagrumab prevents activity of myostatin and other negative regulators of skeletal muscle mass. This randomized double-blind, placebo-controlled study investigated safety, pharmacokinetics (PK), and pharmacodynamics of bimagrumab in healthy older and obese adults.

METHODS

A cohort of older adults (aged 70-85 years) received single intravenous infusions of bimagrumab 30 mg/kg (n = 6) or 3 mg/kg (n = 6) or placebo (n = 4) and was followed for 20 weeks. A second cohort of obese participants [body mass index (BMI) 30-45 kg/m² , aged 18-65 years] received a single intravenous infusion of bimagrumab 30 mg/kg (n = 6) or placebo (n = 2) and was followed for 12 weeks. Outcomes included the safety, tolerability, and PK of bimagrumab, in both cohorts. Measures of pharmacodynamics were performed in the older adult cohort to evaluate the effects of bimagrumab on thigh muscle volume (TMV), total lean body mass (LBM), total fat body mass, and muscle strength.

RESULTS

All 24 randomized participants completed the study. The older adults had a mean (±SD) age of 74.5 ± 3.4 years and BMI of 26.5 ± 3.5 kg/m² . The obese participants had a mean (±SD) age of 40.4 ± 11.8 years, weight of 98.0 ± 11.3 kg, and BMI of 34.3 ± 3.9 kg/m² . Adverse events in both cohorts were mostly mild. In older adults, most commonly reported adverse events were upper respiratory tract infection, rash, and diarrhoea (each 3/16, 19%). Obese participants reported muscle spasms and rash (both 5/8, 63%) most often. Non-linearity was observed in the PK concentration profiles of both cohorts due to target-mediated drug disposition. Bimagrumab 3 and 30 mg/kg increased mean (±SD) TMV (Week 4: 5.3 ± 1.8% and 6.1 ± 2.2%, vs. placebo: 0.5 ± 2.1%, both P ≤ 0.02) and LBM (Week 4: 6.0 ± 3.2%, P = 0.03 and 2.4 ± 2.2%, vs. placebo: 0.1 ± 2.4%), which were maintained longer with higher dose level, while total fat body mass (Week 4: -2.7 ± 2.9% and -1.6 ± 3.0%, vs. placebo: -2.3 ± 3.2%) decreased from baseline in older adults, with no change in muscle strength.

CONCLUSIONS

Bimagrumab was safe and well tolerated and demonstrated similar PK in older and obese adults. A single dose of bimagrumab rapidly increased TMV and LBM and decreased body adiposity in older adults. Muscle hypertrophy and fat loss were sustained with extended drug exposure.

Exercise and the Cisd2 Prolongevity Gene: Two Promising Strategies to Delay the Aging of Skeletal Muscle

Aging is an evolutionally conserved process that limits life activity. Cellular aging is the result of accumulated genetic damage, epigenetic damage and molecular exhaustion, as well as altered inter-cellular communication; these lead to impaired organ function and increased vulnerability to death. Skeletal muscle constitutes ~40% of the human body’s mass. In addition to maintaining skeletal structure and allowing locomotion, which enables essential daily activities to be completed, skeletal muscle also plays major roles in thermogenesis, metabolism and the functioning of the endocrine system. Unlike many other organs that have a defined size once adulthood is reached, skeletal muscle is able to alter its structural and functional properties in response to changes in environmental conditions. Muscle mass usually remains stable during early life; however, it begins to decline at a rate of ~1% year in men and ~0.5% in women after the age of 50 years. On the other hand, different exercise training regimens are able to restore muscle homeostasis at the molecular, cellular and organismal levels, thereby improving systemic health. Here we give an overview of the molecular factors that contribute to lifespan and healthspan, and discuss the effects of the longevity gene Cisd2 and middle-to-old age exercise on muscle metabolism and changes in the muscle transcriptome in mice during very old age.

Cardiovascular risk factors and body composition in adults with achondroplasia

Purpose

An increased cardiovascular mortality has been reported in achondroplasia. This population-based, case–control study investigated cardiovascular risk factors and body composition in Norwegian adults with achondroplasia.

Methods

We conducted anthropometric, clinical, and laboratory assessments in 49 participants with achondroplasia, of whom 40 completed magnetic resonance imaging (MRI) for body composition analysis. Controls consisted of 98 UK Biobank participants, matched for body mass index (BMI), sex, and age.

Results

Participants were well matched for BMI (33.3 versus 32.5 kg/m²) and sex, but achondroplasia participants were younger than controls (mean age 41.1 versus 54.3 years). Individuals with achondroplasia had lower age-adjusted mean blood pressure, total and low-density lipoprotein (LDL) cholesterol, and triglycerides compared with controls, but similar fasting glucose and HbA1c values. Age-adjusted mean visceral fat store was 1.9 versus 5.3 L (difference −2.7, 95% confidence interval [CI] −3.6 to −1.9; P < 0.001), abdominal subcutaneous fat was 6.0 versus 11.2 L (−4.7, 95% CI −5.9 to −3.4; P < 0.001), and liver fat was 2.2 versus 6.9% (−2.8, 95% CI −5.2 to −0.4; P = 0.02).

Conclusion

Despite a high BMI, the cardiovascular risks appeared similar or lower in achondroplasia compared with controls, indicating that other factors might contribute to the increased mortality observed in this condition.

Establishment of normative biometric data for body composition based on computed tomography in a North American cohort

BACKGROUND & AIMS

Accurate and reproducible biomarkers are required to allow a more personalized approach to patient care. Body composition is one such biomarker affecting outcomes in a range of surgical and oncological conditions. The aim of this study is to determine the age and sex specific distribution of body composition data, based on information gathered from computed tomography (CT).

METHODS

This prospective study used healthy subjects from the medical records linkage of the Rochester Epidemiology Project, based in Minnesota, USA. Each patient had a CT scan without intravenous contrast performed between 1999 and 2001. Quantification was performed using previously validated semi-automated in-house developed software for body composition analysis. Subcutaneous adipose tissue area, visceral adipose tissue area, intermuscular adipose tissue area and skeletal muscle area were measured and indexed to subject height. Generalized Additive Models for Location, Scale and Shape were used to assess the location, scale, and shape of each variable across age, stratified by sex. Z-scores specific to sex were assessed for each of the parameters analyzed. Age-specific z-scores were calculated using the formula: Z = (Index Variable - μ)/σ or Z = (√ (Index Variable) - μ)/σ.

RESULTS

There were 692 subjects enrolled in the study. The fitted model equation was offered for each variable with values presented for μ and σ. Modelling with penalized splines was performed for VAT index, IMAT index and total adipose tissue index. Scatterplots of each variable were produced with lines of Z-scores as a visual representation.

CONCLUSION

This study offers comparative data to allow comparison amongst multiple populations. This will form an important reference for future research and clinical practice.

Fully Automated and Standardized Segmentation of Adipose Tissue Compartments via Deep Learning in 3D Whole-Body MRI of Epidemiologic Cohort Studies

PURPOSE

To enable fast and reliable assessment of subcutaneous and visceral adipose tissue compartments derived from whole-body MRI.

MATERIALS AND METHODS

Quantification and localization of different adipose tissue compartments derived from whole-body MR images is of high interest in research concerning metabolic conditions. For correct identification and phenotyping of individuals at increased risk for metabolic diseases, a reliable automated segmentation of adipose tissue into subcutaneous and visceral adipose tissue is required. In this work, a three-dimensional (3D) densely connected convolutional neural network (DCNet) is proposed to provide robust and objective segmentation. In this retrospective study, 1000 cases (average age, 66 years ± 13 [standard deviation]; 523 women) from the Tuebingen Family Study database and the German Center for Diabetes research database and 300 cases (average age, 53 years ± 11; 152 women) from the German National Cohort (NAKO) database were collected for model training, validation, and testing, with transfer learning between the cohorts. These datasets included variable imaging sequences, imaging contrasts, receiver coil arrangements, scanners, and imaging field strengths. The proposed DCNet was compared to a similar 3D U-Net segmentation in terms of sensitivity, specificity, precision, accuracy, and Dice overlap.

RESULTS

Fast (range, 5-7 seconds) and reliable adipose tissue segmentation can be performed with high Dice overlap (0.94), sensitivity (96.6%), specificity (95.1%), precision (92.1%), and accuracy (98.4%) from 3D whole-body MRI datasets (field of view coverage, 450 × 450 × 2000 mm). Segmentation masks and adipose tissue profiles are automatically reported back to the referring physician.

CONCLUSION

Automated adipose tissue segmentation is feasible in 3D whole-body MRI datasets and is generalizable to different epidemiologic cohort studies with the proposed DCNet.Supplemental material is available for this article.© RSNA, 2020.

DNA methylation and adiposity phenotypes: an epigenome-wide association study among adults in the Strong Heart Study

BACKGROUND

Elevated adiposity is often posited by medical and public health researchers to be a risk factor associated with cardiovascular disease, diabetes, and other diseases. These health challenges are now thought to be reflected in epigenetic modifications to DNA molecules, such as DNA methylation, which can alter gene expression.

METHODS

Here we report the results of three Epigenome Wide Association Studies (EWAS) in which we assessed the differential methylation of DNA (obtained from peripheral blood) associated with three adiposity phenotypes (BMI, waist circumference, and impedance-measured percent body fat) among American Indian adult participants in the Strong Heart Study.

RESULTS

We found differential methylation at 8264 CpG sites associated with at least one of our three response variables. Of the three adiposity proxies we measured, waist circumference had the highest number of associated differentially methylated CpGs, while percent body fat was associated with the lowest. Because both waist circumference and percent body fat relate to physiology, we focused interpretations on these variables. We found a low degree of overlap between these two variables in our gene ontology enrichment and Differentially Methylated Region analyses, supporting that waist circumference and percent body fat measurements represent biologically distinct concepts.

CONCLUSIONS

We interpret these general findings to indicate that highly significant regions of the genome (DMR) and synthesis pathways (GO) in waist circumference analyses are more likely to be associated with the presence of visceral/abdominal fat than more general measures of adiposity. Our findings confirmed numerous CpG sites previously found to be differentially methylated in association with adiposity phenotypes, while we also found new differentially methylated CpG sites and regions not previously identified.