Gross anatomical study of the subcutaneous structures that create the three-dimensional shape of the buttocks.

The purpose of this study was to clarify the subcutaneous structures involved in the morphology of the gluteal region for clinical application. Thirty-seven formalin-fixed cadavers and one soft-fixed cadaver were used in this study. Gluteal tissue was removed from five formalin-fixed cadavers. A horizontal section and sections parallel to the long axis of the body were made from the excised tissue, and the subcutaneous fat was removed to observe the fibrous structure within the subcutaneous fat. Two formalin-fixed cadavers and one soft-fixed cadaver were used to perform conventional gross anatomical dissection and histological examination. On 30 formalin-fixed cadavers, the thickness of the subcutaneous fat was measured in various areas of the buttocks. The thickness of subcutaneous fat was thicker in the center of the buttocks and thinner on the lateral buttocks. Superficial fascia (SF) was found only in the upper buttock, being indistinct in the lower buttock. In the sacral and coccygeal areas, the dermis was tightly adhered to the bone as a single mass. Fibers arose from around the iliac crest to the SF. On the medial side of the gluteal fold, a strong fiber arose from the sciatic tubercle and inserted into the gluteus maximus and dermis. By identifying the characteristic subcutaneous structures of the gluteal region, we were able to identify the anatomical structures that shape the three-dimensional morphology of the buttocks. These findings may be useful in surgical treatments such as improving the buttock shape.

Three sublayers in the SMAS: Observations of facial soft tissue using the stretched tissue dissection method focusing on the SMAS.

The characteristics of the superficial musculoaponeurotic system (SMAS), including the morphology of each part and the connection between tissues, remain controversial. The purpose of this study is to clarify the anatomy of the SMAS using our new dissection method. In this study, six hemi-sides of heads from formalin-preserved cadavers were used. Three were used for creating a horizontal section and three were used for creating the section along the axial line perpendicular to the surface of the skin, resulting in a gradual change from the coronal section at the lateral to the sagittal section at the median. The resected head was cut into slices with widths of 7 mm. The stretched tissue dissection method was performed by fixing a tissue slice to a board and pulling the skin outward to stretch the soft tissue. Blunt dissection was then performed under a microscope. The SMAS comprises three layers: superficial, intermediate, and deep. The superficial layer is a thin membrane directly connecting to the septa in the subcutaneous fat. The deep layer is the connective tissue in contact with the sub-SMAS structure. The layer surrounded by the superficial and deep layer of the SMAS is the intermediate layer, containing connective tissue, adipose tissue, and facial muscles. The detailed findings of the SMAS obtained using this method resolve theoretical discrepancies and provide important insight for the field of facial surgery.

A comprehensive morphometric study of visceral and subcutaneous adipose tissue depots in mice, hamsters and rats / Un estudio morfométrico completo de los depósitos de tejido adiposo visceral y subcutáneo en ratones, hámsters y ratas

SUMMARY: Adipose tissue morphology of different fat tissue depots can be described using the number of adipocytes and cell surface of adipocytes. This study deals with characteristics and morphometric analysis of white and brown adipose tissue depots in healthy adult laboratory mice, hamsters and rats of both sexes. The number of unilocular adipocytes in white adipose tissue differs from one adipose tissue depot to another, with the largest number of adipocytes in mice and a similar number in hamsters and rats. The smallest surface area and the largest percentage of small unilocular adipocytes were found in mice. White adipose tissue in hamsters and rats was predominantly made out of a larger percentage of medium-sized adipocytes and a smaller percentage of small and medium-sized adipocytes. Uncoupling protein 1 positive multilocular adipocytes were found in classic brown adipose tissue depots with larger percentages in mice (93.20 %) and hamsters (91.30 %), while rats had a smaller percentage (78.10 %). In white and brown adipose tissue, significant differences between species and both sexes within the same species were found, indicating the influence of sexual dimorphism. The presented morphometric results could serve as a basis for further studies concerning experimental animal models of metabolic disorders and obesity.

RESUMEN: La morfología del tejido adiposo de diferentes depósitos de tejido graso se puede describir utilizando el número de adipocitos y la superficie celular de los adipocitos. Este estudio analiza las características y el análisis morfométrico de los depósitos de tejido adiposo blanco y marrón en ratones, hamsters y ratas de laboratorio, adultos sanos de ambos sexos. El número de adipocitos uniloculares en el tejido adiposo blanco difiere de un depósito de tejido adiposo a otro, con el mayor número de adipocitos en ratones y un número similar en hámsteres y ratas. La superficie más pequeña y el mayor porcentaje de adipocitos uniloculares pequeños se encontraron en ratones. El tejido adiposo blanco en hámsteres y ratas estaba compuesto predominantemente por un mayor porcentaje de adipocitos de tamaño mediano y un porcentaje menor de adipocitos de tamaño pequeño y mediano. Los adipocitos multiloculares positivos para la proteína desacopladora 1 se encontraron en depósitos de tejido adiposo marrón clásico con mayores porcentajes en ratones (93,20 %) y hámsters (91,30 %), mientras que las ratas tenían un porcentaje menor (78,10 %). En el tejido adiposo blanco y pardo se encontraron diferencias significativas entre especies y entre ambos sexos dentro de una misma especie, lo que indica la influencia del dimorfismo sexual. Los resultados morfométricos presentados podrían servir como base para futuros estudios sobre modelos animales experimentales de trastornos metabólicos y obesidad.

Association of body-shape phenotypes with imaging measures of body composition in the UK Biobank cohort: relevance to colon cancer risk.

BACKGROUND: Body mass index (BMI), waist and hip circumference are strongly correlated and do not reflect body composition. A Body Shape Index (ABSI) and Hip Index (HI) define waist and hip size among individuals with the same weight and height and would thus reflect body density. We examined differences in body composition between body-shape phenotypes defined with ABSI and HI and used this information to propose explanations for associations between body-shape phenotypes and colon cancer risk. METHODS: We used data from the UK Biobank Resource for 15,520 men, 16,548 women with dual-emission X-ray absorptiometry (DXA) measurements; 3997 men, 4402 women with magnetic resonance imaging (MRI) measurements; 200,289 men, 230,326 women followed-up for colon cancer. We defined body-shape phenotypes as: large-ABSI-small-HI ("apple"), small-ABSI-large-HI ("pear"), small-ABSI-small-HI ("slim"), large-ABSI-large-HI ("wide"). We evaluated differences in body composition in linear models and associations with colon cancer risk in Cox proportional hazards models adjusted for confounders and explored heterogeneity by BMI. RESULTS: Among individuals with the same height and weight, visceral adipose tissue (VAT) was lowest for "pear" and highest for "apple", while abdominal subcutaneous adipose tissue (ASAT) was lowest for "slim" and highest for "wide" phenotype. In the gynoid region, differences between "apple" and "pear" phenotypes were accounted for mainly by fat mass in women but by lean mass in men. In men, lean mass was inversely associated with waist size, while the pattern of gynoid fat resembled ASAT in women. Lean and fat mass were higher for higher BMI, but not hand grip strength. Compared to normal weight "pear", the risk of colon cancer in men (1029 cases) was higher for "apple" phenotype for normal weight (hazard ratio HR = 1.77; 95% confidence interval: 1.16-2.69) and comparably for overweight and obese, higher for "wide" phenotype for overweight (HR = 1.60; 1.14-2.24) and comparably for obese, but higher for "slim" phenotype only for obese (HR = 1.98; 1.35-2.88). Associations with colon cancer risk in women (889 cases) were weaker. CONCLUSIONS: ABSI-by-HI body-shape phenotypes provide information for body composition. Colon cancer risk in men appears related to ASAT quantity for "slim" and "wide" but to factors determining VAT accumulation for "apple" phenotype.

The role of age in the physiological adaptations and psychological responses in bikini-physique competitor contest preparation: a case series.

The increased popularity of the bikini-physique competitions has not translated to greater research identifying the influence of age on adaptations during contest preparation. The purpose of this case series was to observe how age may influence the adaptations normally seen during preparation and the exploration of newer protocols to address adaptations more relative to the judging standards. Over a 16-week pre-contest preparation, a 32-y bikini competitor (BC) and 44-y master's bikini competitor (MBC) visited the laboratory bi-weekly to observe changes in body fat mass (BF), lean body mass (LBM), bone mineral density (BMD), total body water (TBW); exploratory measures of deltoid cross-sectional area (DeltCSA), gluteus maximus muscle thickness (GMMT), and subcutaneous adipose tissue thickness (SAT); reproductive hormones estradiol (E2), luteinizing hormone (LH), and energy balance hormones triiodothyronine (T3), leptin and ghrelin; hydration status during contest preparation and the week of competition; resting metabolic rate (RMR); psychometric data related to perceived anxiety, stress, and body image were assessed. No differences between BC and MBC were observed in BF, LBM, BMD, and TBW. Both competitors showed a small loss in LBM. Both BC and MBC showed a contrasting increase in DeltCSA and a loss in GMMT. MBC showed to be slightly more dehydrated (1.025 vs 1.021 g·mL- 1) than BC. Both competitors maintained a euhydration status the day of the competition. No time differences were found between BC and MBC during RMR. BC showed a higher mean difference RMR compared to MBC (2.66 ± 0.75 kcal·kgLBM- 1·d- 1). MBC showed a higher mean difference in LH concentration (84.6 ± 6.01 IU·L- 1), which may be explained by perimenopausal status. MBC had a higher mean difference concentration of leptin (2.51 ± 0.24 ng·mL- 1·kgFM- 1), which was unperturbed by fat loss may be interrelated LH. BC self-reported a higher mean energy intake (15.07 ± 3.43 kcal·kgLBM- 1·d- 1) and higher aerobic training volume (93.26 ± 40.68 min·d). BC and MBC showed similar composition changes, slightly differing metabolic rates, and differing hormonal LH and leptin responses. This finding is in contrast to previous work showing both LH inhibition and leptin diurnal disturbance in younger, female athletes with low energy availability. The exploratory measures may have some benefit for bikini-physique competitors related to the judging criteria. Age did not seem to play a role in contest preparation adaptations.

Reliability and validity of a standardised ultrasound examination protocol to quantify vastus lateralis muscle.

OBJECTIVE: To evaluate the reliability and validity of a standardized ultrasound examination protocol for measuring vastus lateralis muscle size. DESIGN: Prospective cohort study. SUBJECTS: Sixteen staff members of the university hospital of Heidelberg. METHODS: Muscle thickness, cross-sectional area and subcutaneous adipose tissue thickness were measured at 3 standardized sites on the right and left vastus lateralis muscle. Ultrasound measurements were collected by 2 independent investigators on 2 different days and compared with magnetic resonance imaging measurements. RESULTS: Intraclass correlation coefficients (ICC) for intra- and inter-rater reliability showed very good closeness of agreement for all parameters (ICC = 0.929-0.994, p < 0.001). Muscle thickness and subcutaneous adipose tissue thickness ultrasound and magnetic resonance imaging measurements revealed good to very good closeness of agreement (ICC = 0.835-0.969, p < 0.001), whereas cross-sectional area showed only average closeness of agreement (ICC = 0.727, p < 0.001). A strong predictive positive correlation for ultrasound and magnetic resonance imaging-based measurements of cross-sectional area was found (R² = 0.793, p < 0.001). CONCLUSION: By standardization of an examination protocol, quantitative vastus lateralis muscle ultrasound proved to be a reliable method for assessing vastus lateralis muscle size. Furthermore, this protocol is valid for measuring muscle thickness and subcutaneous adipose tissue thickness, although there seems to be a systematic underestimation of cross-sectional area depending on subcutaneous adipose tissue thickness.

Three-dimensional topography of facial soft tissues for the safer and effective threading procedures.

INTRODUCTION: To reduce complications caused by the procedure, the target layer for thread lifting should be the superficial fat or superficial musculoaponeurotic system of the face. The aim of this study was to establish the thicknesses of the facial skin and superficial fat using a 3D scanning system to provide basic clinical data for thread lifting. MATERIAL AND METHODS: Thirty fixed Korean and Thai cadavers (male: 17, female: 13) were used. The depths of the skin and superficial fat were measured using a three dimensional (3D) structured-light scanner. Facial images of both undissected and removed skin and superficial fat were taken with the 3D scanner. The paths from the temple and the front of the tragus to the infraorbital, perioral, cheek, and mental areas were displayed on the 3D image. The thickness along the path was measured by calculating the difference between the undissected and dissected 3D images. RESULTS: The means and standard deviations of thicknesses of the skin and superficial fat were 2.1 ± 0.4 mm and 5.2 ± 1.9 mm in the 11 pathways. The facial skin became thicker going toward the lower aspect of the face from temple to infraorbtial and perioral regions. The thickness of the superficial fat around the marionette line showed the biggest change. CONCLUSIONS: The present findings indicate that a 3D scanning system can yield crucial anatomical information about the thickness of the facial skin and superficial fat for use in various minimally invasive clinical procedures including thread lifting.

Ultrawide band microwave system as a non-invasive technology to predict beef carcase fat depth.

A portable ultra-wide band microwave system (MiS) coupled with an open-ended coaxial probe (OCP) or Antipodal Vivaldi Antenna (VPA) was tested as a non-invasive objective measurement to predict beef carcase single site fat depth at commercial abattoirs. Experiment one tested the effectiveness of MiS coupled with a VPA. The VPA was used to predict hot carcase P8 (fat depth on the rump) across 4 slaughter groups (n = 241). The VPA was also used to predict cold carcase rib fat (at the quartering site, 75% along the rib eye muscle) across 5 slaughter groups (n = 598). Experiment two tested the ability of MiS coupled with OCP to measure hot carcase P8 across two slaughter groups (n = 435). A machine learning stacking ensemble method was used to create the prediction equations. Datasets were grouped by prediction trait (P8 or ribfat) and probe/antenna then randomly divided into 5 groups based on tissue depth. Precision was greatest using OCP to predict P8 fat depth with a RMSEP of 2.47 mm and R2 of 0.70. The VPA precision was similar for the two tissue depths assessed, hot carcase P8 had an average RMSEP of 2.86 mm and R2 of 0.58 compared to cold carcase rib fat RMSEP of 2.60 mm and R2 of 0.55.

Competitive Performance of Kenyan Runners Compared to their Relative Body Weight and Fat.

Body fat values obtained with various measurement methods deviate substantially in many cases. The standardised brightness-mode ultrasound method was used in 32 Kenyan elite long-distance runners to measure subcutaneous adipose tissue thicknesses at an accuracy and reliability level not reached by any other method. Subcutaneous adipose tissue forms the dominating part of body fat. Additionally, body mass (m), height (h), sitting height (s), leg length, and the mass index MI1 =0.53m/(hs) were determined. MI1 considers leg length, which the body mass index ignores. MI1 values of all participants were higher than their body mass indices. Both indices for relative body weight were within narrow ranges, although thickness sums of subcutaneous adipose tissue deviated strongly (women: 20-82 mm; men: 3-36 mm). Men had 2.1 times more embedded fasciae in the subcutaneous adipose tissue. In the subgroup with personal best times below world record time plus 10%, no correlation between performance and body mass index was found, and there was also no correlation with sums of subcutaneous adipose tissue thicknesses. Within the data ranges found here, extremely low relative body weight or low body fat were no criteria for the level of performance, therefore, pressure towards too low values may be disadvantageous.

Prediction of Facial Aging Using the Facial Fat Compartments.

SUMMARY: Facial aging is a multifactorial process governed by both intrinsic and extrinsic factors that impart a change to each component of the facial anatomy. Our understanding of the science of aging has evolved over the years. A recent and valuable addition to our understanding is the knowledge of both the superficial and deep facial fat compartments. The deep compartments provide structural support to the midface and the superficial fat compartments. Understanding the anatomy and the spectrum of their changes helps to tailor management options for facial rejuvenation. The authors present a review on facial aging as it relates to these fat compartments and provide a management algorithm based on the longitudinal changes seen during aging.

Genetic parameters associated with meat quality of Nellore cattle at different anatomical points of longissimus: Brazilian standards.

The present study estimated genetic parameters and evaluated the genetic and phenotypic correlations between meat quality characteristics of Nellore cattle evaluated at different anatomical points of the longissimus. Data from 1329 Nellore young bulls were used to evaluate, in the 5th and 12th ribs, marbling score (MAR), shear force (SF), cooking weight losses (CWL) and intramuscular fat (IMF). In addition, the subcutaneous fat thickness was measured at the 12th rib (SFT12) and between the last lumbar and the first sacral vertebrae (SFTLR), in the separation of loin and round. Results yielded moderate heritability coefficients for evaluated characteristics, except CWL. High genetic correlations (0.61) were found between measurements of SFT12 and SFTLR. MAR, IMF and SF were evaluated at the 5th and 12th rib. Meat quality and subcutaneous fat thickness measured at different anatomical points of the longissimus are genetically correlated and can be used in genetic selection programs to improve meat quality characteristics in Nellore cattle.

Facial Aging: A Quantitative Analysis of Midface Volume Changes over 11 Years.

BACKGROUND: Anatomical studies have identified separate superficial and deep facial fat compartments, leading some to theorize that volume loss from the deep midface causes overlying superficial fat pseudoptosis. Unfortunately, a paucity of evidence exists regarding whether facial fat volume is truly lost with age and, if so, whether it is lost equally or differentially from the superficial and deep compartments. The aim of this study was to quantify volume changes occurring with age within the superficial, deep, and buccal fat compartments of the midface. METHODS: A retrospective longitudinal study was performed evaluating individuals aged 30 to 65 years who underwent facial computed tomography followed by facial computed tomography greater than or equal to 10 years later. Superficial midface, deep midface, and buccal fat volumes were quantified using Horos radiology software. RESULTS: Nineteen subjects met inclusion criteria. Mean total fat volume decreased significantly from 46.47 cc to 40.81 cc (p < 0.01). The mean superficial and deep fat volumes both decreased significantly from 26.10 cc to 23.15 cc (p < 0.01) and from 11.01 cc to 8.98 cc (p < 0.01), respectively. No significant difference was observed in buccal fat volume over time (9.36 cc to 8.68 cc; p = 0.04). Patients lost an average of 11.3 percent of their initial superficial fat volume and 18.4 percent of their initial deep fat volume. CONCLUSIONS: Significant volume loss was observed from both superficial and deep facial fat compartments over a mean 11.3 years. Patients lost a greater percentage of deep facial fat volume, providing support for the theory of pseudoptosis caused by deep midface fat loss.

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.

Interrater reliability of novice examiners using A-mode ultrasound and skinfolds to measure subcutaneous body fat.

Examiners with minimal training and skill are often called upon to make body composition assessments using field methods. This study compared the interrater reliability of novice examiners for the skinfold (SKF) and A-mode ultrasound (US) methods of body composition assessment. Undergraduate Kinesiology majors (48 males, 32 females) with minimal training took both SKF and US measurements at three sites (males: chest, abdomen, thigh; females: triceps, suprailiac, thigh). Interrater reliability was significantly better for US compared to SKF at the thigh (ICCUS = 0.975, ICCSKF = 0.912) and abdomen (ICCUS = 0.984, ICCSKF = 0.693) for men and suprailiac (ICCUS = 0.978, ICCSKF = 0.883) for women. Additionally, interrater reliability of the US method was superior to the SKF method for the estimate of male body fat percentage (ICCUS = 0.990, ICCSKF = 0.862). The 95% CI was generally narrower for the US method than the SKF method at each site. The interrater reliability of the US method was superior to or equal to the SKF method for measuring subcutaneous body fat when novice examiners took the measurements.

Attitudes Toward Submental Fat Among Adults in the United States.

BACKGROUND: Excess submental fat (SMF) can cause submental fullness resulting in negative perceptions of individuals. However, the impact of SMF on perceptions of social traits has not been well studied. OBJECTIVE: To characterize the impact of SMF on external value judgments in adults in the United States. METHODS: Respondents completed an online survey in which they reacted to statements about individuals with varying grades of SMF. Attributes were rated on a scale from 0 to 100 with higher scores for more positive attributes. RESULTS: Similar proportions of respondents (N = 1996) indicated that women and men with double chins were less attractive than those without (91% and 90%, respectively). A double chin was more likely to be noticed on a woman than on a man (78% of respondents). With increasing SMF, individuals were perceived as significantly less likeable, intelligent, happy, active, and easygoing. Those with greater amounts of SMF were rated as significantly less attractive than those with less SMF. For all attributes, male respondents rated all individuals lower than female respondents did. CONCLUSION: Results from this study provide further evidence of negative perceptions of individuals with SMF. Aesthetics of the submental area, especially SMF, likely impact the overall assessment of attractiveness and social attributes.

Increased fat depth is not associated with increased risk of surgical complications following total hip arthroplasty.

AIMS: Previous research has demonstrated increased early complication rates following total hip arthroplasty (THA) in obese patients, as defined by body mass index (BMI). Subcutaneous fat depth (FD) has been shown to be an independent risk factor for wound infection in cervical and lumbar spine surgery, as well as after abdominal laparotomy. The aim of this study was to investigate whether increased peritrochanteric FD was associated with an increased risk of complications in the first year following THA. METHODS: We analyzed prospectively collected data on a consecutive series of 1,220 primary THAs from June 2013 until May 2018. The vertical soft tissue depth from the most prominent part of the greater trochanter to the skin was measured intraoperatively using a sterile ruler and recorded to the nearest millimetre. BMI was calculated at the patient's preoperative assessment. All surgical complications occuring within the initial 12 months of follow-up were identified. RESULTS: Females had a significantly greater FD at the greater trochanter in comparison to males (median 3.0 cm (interquartile range (IQR) 2.3 to 4.0) vs 2.0 cm (IQR 1.7 to 3.0); p < 0.001) despite equivalent BMI between sexes (male median BMI 30.0 kg/m2 (IQR 27.0 to 33.0); female median 29.0 kg/m2 (IQR 25.0 to 33.0)). FD showed a weak correlation with BMI (R² 0.41 males and R² 0.43 females). Patients with the greatest FD (upper quartile) were at no greater risk of complications compared with patients with the lowest FD (lower quartile); 7/311 (2.3%) vs 9/439 (2.1%); p = 0.820 . Conversely, patients with the highest BMI (≥ 40 kg/m2) had a significantly increased risk of complications compared with patients with lower BMI (< 40 kg/m2); 5/60 (8.3% vs 18/1,160 (1.6%), odds ratio (OR) 5.77 (95% confidence interval (CI) 2.1 to 16.1; p = 0.001)). CONCLUSION: We found no relationship between peritrochanteric FD and the risk of surgical complications following primary THA. Cite this article: Bone Joint J 2020;102-B(9):1146-1150.

Aging Changes of the Superficial Fat Compartments of the Midface Over Time: A Magnetic Resonance Imaging Study.

BACKGROUND: Studies involving superficial facial fat compartments are few in number with conflicting results. Most of them involved small study groups and compared measurements between different populations of young and old subjects either on cadavers or living subjects. OBJECTIVE: To clarify volumetric and dimensional changes in midfacial superficial fat compartment retrospectively in patients who underwent a repeat magnetic resonance imaging (MRI) without gross pathology. MATERIALS AND METHODS: A total of 70 patients with a mean age of 60 years (range: 33-82 years) and a median elapsed time of 44.5 months (range: 32-64 months) between 2 MRIs were included. Magnetic resonance imaging scans were analyzed in the axial and sagittal planes to obtain measurements of the medial part of the superficial cheek fat. Superficial cheek fat was divided into 3 compartments. Thickness, width, and height were measured, and volumes were calculated for each compartment on both hemifaces. RESULTS: Volume and thickness were decreased significantly in all compartments (p < .05). The width was decreased in superior and middle compartments, whereas increased in lower compartment indicating dislocation of the fat tissue (p < .05). Height was also significantly increased (p < .05). A subgroup analysis has shown that there was no significant difference between men and women. CONCLUSION: This study clarifies that aging is associated with a significant decrease in superficial midfacial fat tissue volume and thickness both in women and men. The decrease in width in upper and middle compartments, but increase in lower compartment suggests a volume shift within superficial fat tissue.

Evaluating body composition by combining quantitative spectral detector computed tomography and deep learning-based image segmentation.

PURPOSE: Aim of this study was to develop and evaluate a software toolkit, which allows for a fully automated body composition analysis in contrast enhanced abdominal computed tomography leveraging the strengths of both, quantitative information from dual energy computed tomography and simple detection and segmentation tasks performed by deep convolutional neuronal networks (DCNN). METHODS AND MATERIALS: Both, public and private datasets were used to train and validate DCNN. A combination of two DCNN and quantitative thresholding was used to classify axial CT slices to the abdominal region, classify voxels as fat and muscle and to differentiate between subcutaneous and visceral fat. For validation, patients undergoing repetitive examination (±21 days) and patients who underwent concurrent bioelectrical impedance analysis (BIA) were analyzed. Concordance correlation coefficient (CCC), linear regression and Bland-Altman-Analysis were used as statistical tests. RESULTS: Results provided from the algorithm toolkit were visually validated. The automated classifier was able to extract slices of interest from the full body scans with an accuracy of 98.7 %. DCNN-based segmentation for subcutaneous fat reached a mean dice similarity coefficient of 0.95. CCCs were 0.99 for both muscle and subcutaneous fat and 0.98 for visceral fat in patients undergoing repetitive examinations (n = 48). Further linear regression and Bland-Altman-Analyses suggested good agreement (r2:0.67-0.88) between the software toolkit and patients who underwent concurrent BIA (n = 39). CONCLUSION: We describe a software toolkit allowing for an accurate analysis of body composition utilizing a combination of DCNN- and threshold-based segmentations from spectral detector computed tomography.

Large mid-upper arm circumference is associated with metabolic syndrome in middle-aged and elderly individuals: a community-based study.

BACKGROUND: The mid-upper arm circumference (MUAC) is a proxy for subcutaneous fat in the upper body and is a reliable screening measure for identifying individuals with abnormal regional fat distribution. The purpose of this study was to evaluate the association between MUAC and metabolic syndrome (MetS) in middle-aged and elderly individuals. METHODS: We measured the MUAC in a cross-sectional sample with a total of 9787 subjects aged 40 years and older. The measurement of MUAC is performed on the right arm using a non-elastic tape held midway between the acromion and the olecranon processes in duplicate, with the arm hanging loosely at the side of the body. The MetS was defined according to the Joint Statement of the International Diabetes Federation Task Force on Epidemiology and Prevention. RESULTS: MUAC was positively correlated with waist circumference (r = 0.437, P < 0.001), BMI (r = 0.334, P < 0.001), fasting insulin (r = 0.348, P < 0.001), HOMA-IR (r = 0.134, P < 0.001), triglycerides (r = 0.138, P < 0.001), SBP (r = 0.124, P < 0.001), and DBP (r = 0.123, P < 0.001), and inversely correlated with adiponectin (r = - 0.147, P < 0.001) and HDL-cholesterol (r = - 0.176, P < 0.001) after adjusting for age and gender. Compared with the lowest quartile group, the odds ratios were substantially higher for MetS (OR 1.77; 95% CI 1.51-2.09, P for trend< 0.001) in the highest MUAC quartile group after adjustment for potential cofounder. CONCLUSION: Large mid-upper arm circumference is significantly associated with metabolic syndrome in middle-aged and elderly individuals.