Analysis of volume and topography of adipose tissue in the trunk: Results of MRI of 11,141 participants in the German National Cohort.

This research addresses the assessment of adipose tissue (AT) and spatial distribution of visceral (VAT) and subcutaneous fat (SAT) in the trunk from standardized magnetic resonance imaging at 3 T, thereby demonstrating the feasibility of deep learning (DL)-based image segmentation in a large population-based cohort in Germany (five sites). Volume and distribution of AT play an essential role in the pathogenesis of insulin resistance, a risk factor of developing metabolic/cardiovascular diseases. Cross-validated training of the DL-segmentation model led to a mean Dice similarity coefficient of >0.94, corresponding to a mean absolute volume deviation of about 22 ml. SAT is significantly increased in women compared to men, whereas VAT is increased in males. Spatial distribution shows age- and body mass index-related displacements. DL-based image segmentation provides robust and fast quantification of AT (≈15 s per dataset versus 3 to 4 hours for manual processing) and assessment of its spatial distribution from magnetic resonance images in large cohort studies.

Effects of plant and animal high protein diets on immune-inflammatory biomarkers: A 6-week intervention trial.

BACKGROUND & AIMS: Pro-inflammatory biomarkers are well-established contributors to insulin resistance and represent valid targets for diabetes management and prevention. Yet, little is known whether nutrition could play a role in modulating various aspects of immune-inflammatory responses. Our aim is to assess the effect of isocaloric animal and plant protein dietary interventions on selected biomarkers representing various immune-inflammatory pathways. METHODS: We enrolled 37 participants with type 2 diabetes (age 64 ± 6 years, body mass index 30.2 ± 3.6 kg/m2, glycated hemoglobin 7.0 ± 0.6%) who underwent an either high-animal protein (AP) or high-plant protein (PP) diet (30 E% protein, 40 E% carbohydrates, 30 E% fat) for 6-weeks. Clinical examinations were performed at beginning and end of the study. Levels of pro-inflammatory adipokines [chemerin, progranulin], cytokines [tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), soluble urokinase-type plasminogen activator receptor (suPAR), transforming growth factor beta 1 (TGF-ß1)], and proteins [calprotectin, lactoferrin and growth differentiation factor 15 (GDF-15)] were determined in blood serum using enzyme-linked immunosorbent assay. RESULTS: Chemerin and progranulin concentrations decreased following AP and PP diets. TGF-ß1 increased in AP and decreased in PP, whereas calprotectin increased in PP and decreased in AP. No statistically significant differences in the concentrations of IL-6, TNF-α, suPAR, lactoferrin and GDF-15 could be seen in either of the protein diet arms. CONCLUSIONS: These results suggest that both AP and PP diets may effectively reduce the levels of the pro-inflammatory adipokines chemerin and progranulin. The effects on the additional immune-inflammatory biomarkers seem to be more complex. CLINICAL TRIAL REGISTRY NUMBER: NCT02402985 (ww.clinicaltrials.gov).

Association between Thigh Muscle Volume and Leg Muscle Power in Older Women.

The construct of sarcopenia is still discussed with regard to best appropriate measures of muscle volume and muscle function. The aim of this post-hoc analysis of a cross-sectional experimental study was to investigate and describe the hierarchy of the association between thigh muscle volume and measurements of functional performance in older women. Thigh muscle volume of 68 independently living older women (mean age 77.6 years) was measured via magnetic resonance imaging. Isometric strength was assessed for leg extension in a movement laboratory in sitting position with the knee flexed at 90° and for hand grip. Maximum and habitual gait speed was measured on an electronic walk way. Leg muscle power was measured during single leg push and during sit-to-stand performance. Thigh muscle volume was associated with sit-to-stand performance power (r = 0.628), leg push power (r = 0.550), isometric quadriceps strength (r = 0.442), hand grip strength (r = 0.367), fast gait speed (r = 0.291), habitual gait speed (r = 0.256), body mass index (r = 0.411) and age (r = -0.392). Muscle power showed the highest association with thigh muscle volume in healthy older women. Sit-to-stand performance power showed an even higher association with thigh muscle volume compared to single leg push power.

Magnetic resonance imaging based determination of body compartments with the versatile, interactive sparse sampling (VISS) method.

PURPOSE: To investigate the inhomogeneity of radiofrequency fields at higher field strengths that can interfere with established volumetric methods, in particular for the determination of visceral (VAT) and subcutaneous adipose tissue (SCAT). A versatile, interactive sparse sampling (VISS) method is proposed to determine VAT, SCAT, and also total body volume (TBV). MATERIALS AND METHODS: VISS is based on a separation of major components by contour lines, followed by a sparse sampling algorithm, and eventually a quick manual correction. T1-weighted whole body scans of 24 subjects were evaluated (12 at 1.5T, 12 at 3.0T). RESULTS: (a) Coefficients of variance (CV) and intra class correlation coefficients (ICC) determined within 3 raters (24 subjects) showed high consistency for SCAT (CV 2.2%, ICC 0.993) and VAT (CV 4.9%, ICC 0.987), (b) comparison with an established volumetric method revealed good agreement (Bland-Altman, VAT -0.68L to 1.07L, SCAT -2.18L to 8.39L), and (c) comparison of weights calculated from TBV with values measured on a scale resulted in an even better accuracy for VISS (Bland-Altman -1.98 kg to 4.09 kg) than for the reference method (-5.60 kg to 1.60 kg). CONCLUSION: VISS is reproducible in particular within the same rater, accurate as compared with established methods, and robust against low contrast and inhomogeneity artifacts.

Cholesterol synthesis is associated with hepatic lipid content and dependent on fructose/glucose intake in healthy humans.

Visceral obesity and fatty liver have been related to high synthesis and low absorption of cholesterol. This study aimed to investigate the associations of cholesterol metabolism with liver and visceral fat content in healthy humans. Another objective was to explore the effects of very-high-fructose and very-high-glucose diets on cholesterol homeostasis. We report on a cohort of 20 people (12 males, 8 females; age 30.5 ± 2.0 years; body mass index 25.9 ± 0.5 kg/m(2)) who completed a four-week dietary intervention study. Between the baseline and the followup examination the study participants in addition to a balanced weight-maintaining diet received 150 g of either fructose or glucose per day. Visceral and liver fat were measured with magnetic resonance (MR) imaging and (1)H-MR spectroscopy, respectively. Cholesterol absorption and synthesis were estimated from the serum noncholesterol sterol concentrations. Performing cross-sectional analyses the lanosterol and desmosterol to cholesterol ratios were positively correlated with visceral and liver fat content (all P < .03). The lathosterol to cholesterol ratio decreased in response to high-fructose diet (P = .006) but not in response to high-glucose diet. To conclude, visceral and liver fat content are associated with cholesterol synthesis in healthy humans. Furthermore, cholesterol synthesis appears to be dependent on fructose/glucose intake.

Active depression is associated with regional adiposity in the upper abdomen and the neck.

OBJECTIVE: In major depression, the incidence of overweight, the risk of type 2 diabetes, as well as cardiovascular disease is increased. Aim was to determine body fat distribution in depressive and healthy females using whole body Magnetic Resonance Imaging (MRI). Measurements of total adipose tissue (TAT), visceral (VAT), and subcutaneous adipose tissue (SCAT) at the trunk and the whole body fat distribution along the body axis were performed and compared. Differences in body fat distribution between depressive and healthy females and their location were evaluated. METHODS: In total, 11 women with a depressive syndrome (major depression, MD) and 45 healthy female volunteers (HC) matched for age and body mass index were compared. Total tissue (TT), TAT, VAT, and SCAT were quantified using T1-weighted whole body MRI. Adipose tissue distribution was compared along the body axis. RESULTS: MD patients showed higher adipose tissue volumes than the HC group. Especially in the upper abdomen, at the upper extremities and the neck, MD patients are characterized by a significantly higher adipose tissue mass compared to the HC group. CONCLUSIONS: The results of this study confirm the hypothesis of a high stress level with a disturbed hypothalamic-pituitary-adrenal (HPA) axis leading to a Cushing-like habitus and high visceral fat levels. The increased fat levels at the arms, as well as the whole body fat may be well-founded by a lack of activity in depression. These effects should be evaluated in further longitudinal studies investigating patients with a depressive syndrome and after remission.

Subcutaneous adipose tissue thickness in adults - correlation with BMI and recommendations for pen needle lengths for subcutaneous self-injection.

OBJECTIVE: One of the aims of a subcutaneous (SC) injection is to avoid intradermal or intramuscular injections. Pen systems are an alternative solution to single-use syringes and have become standard for example diabetes therapy. Shorter and smaller needles minimize pain and the risk of intramuscular injections. The thickness of subcutaneous adipose tissue (SCAT) varies with position and with body mass index (BMI). The aim of this study was the creation of a map of SCAT thickness at typical spots for SC self-injection. MATERIALS AND METHODS: MRI scans of 116 prospectively enroled volunteers (56 men and 60 women) were analysed. SCAT thickness was determined at 17 spots over the abdominal wall, left thigh, buttocks and upper arm, typical sites for subcutaneous self-injection. SCAT thicknesses were correlated with BMI and waist-to-hip ratio (WHR), and a linear curve fit was performed. The best fitting linear functions for the prediction of the SCAT thickness dependent on BMI and WHR were derived. RESULTS: Correlations between SCAT and BMI were higher (0·67-0·21) than with WHR (-0·67 to 0·09). In women, correlation coefficients between SCAT data at the abdomen and BMI/WHR were higher than in men. On the other hand, data showed better correlations at the extremities in men. CONCLUSIONS: The data, with correlation between BMI and fat thickness at different injection sites in relation to gender, provide guidance in selecting an adequate pen needle length for deep and safe subcutaneous self-injection. WHR was a much weaker predictor when compared to BMI.

Effects of 4-week very-high-fructose/glucose diets on insulin sensitivity, visceral fat and intrahepatic lipids: an exploratory trial.

An increasing amount of fructose in the diet is suggested to play a causal role in the pathogenesis of the metabolic syndrome, type 2 diabetes and fatty liver. Our aim was to investigate and compare the effects of very high fructose and very high glucose in hyperenergetic diets on glucose and lipid metabolism and on fat depots in healthy humans. We conducted an exploratory, prospective, randomised, single-blinded, intervention trial. Participants in addition to a balanced weight-maintaining diet received 150 g of fructose or glucose/d for 4 weeks. Insulin sensitivity was estimated from oral glucose tolerance tests. Visceral and subcutaneous abdominal fat was determined with MRI. Liver fat and intramyocellular lipids of the tibialis anterior muscle were measured with (1)H magnetic resonance spectroscopy. A total of twenty healthy subjects (fructose group n 10 and glucose group n 10; twelve males and eight females) completed the study. They had a mean age of 30·5 (SEM 2·0) years and a mean BMI of 25·9 (SEM 0·5) kg/m(2). Insulin sensitivity appeared to decrease both in the fructose and glucose groups. TAG markedly increased in the fructose group. No strong alterations or treatment effects were found for liver fat, visceral fat, subcutaneous abdominal fat and intramyocellular lipids of the tibialis anterior muscle. In conclusion, the effects of very high fructose and very high glucose in hyperenergetic diets on glucose metabolism and body fat composition were not different in the healthy participants of the present study. However, elevation of plasma TAG seemed to be fructose-specific.

Changes in muscular lipids in unilateral isolated hypertrophy of gastrocnemius muscle can be revealed by 1H MR spectroscopy.

OBJECTIVE: To test whether proton magnetic resonance spectroscopy ((1)H-MRS) reveals changes in the lipid content of the gastrocnemius muscle (GM) and soleus muscle (SOL) of a patient with unilateral isolated hypertrophy of the right GM. MATERIALS AND METHODS: (1)H-MRS was performed on a 1.5 Tesla (T) whole-body unit. Muscular lipids inside SOL and GM were assessed in both calves of the patient by a STEAM (stimulated echo acquisition mode) localization sequence. Results were compared to a control group of four healthy volunteers. RESULTS: Total amount of muscular lipids in the hypertrophic GM of the patient was clearly increased compared to the controls (38.7 versus 21.8+/-3.5 a.u.) while intramyocellular lipids of the adjacent SOL were lower compared to the contralateral healthy leg. CONCLUSION: Muscular lipids are substrates for metabolism and can be assessed non-invasively by (1)H-MRS. (1)H-MRS is considered to be a helpful tool in clinical assessment of muscle metabolism in cases with muscular hypo- or hypertrophy.

Correlation of fat distribution in whole body MRI with generally used anthropometric data.

OBJECTIVES: : Obesity is a commonly known risk for many diseases such as metabolic syndrome and cardiovascular disease. Especially important is the discrimination of the adipose tissue inside the abdomen and the subcutaneous adipose tissue. Aim of this study was to compare the whole body fat distribution, and the volume of different adipose tissue compartments respectively, with anthropometric data. MATERIALS AND METHODS: : Sixty-eight volunteers (20 males, 48 females, 42.3 +/- 15.4 years) were investigated in the context of 2 whole body magnetic resonance imaging (MRI) studies which compared the body fat distribution of depressive and bulimic patients with healthy controls. Unpublished data acquired in these studies were analyzed retrospectively.The sample consisted of 38 healthy volunteers, 17 patients with a depressive syndrome and 13 women suffering from bulimia nervosa. Individual body volume, total adipose tissue (TAT) volume, subcutaneous adipose tissue (SCAT) volume at the trunk, and visceral adipose tissue (VAT) volume were determined, using whole body MRI. Additionally, body fat profiles were standardized and a mean body distribution was calculated. Other modalities to acquire body fat content were: skin fold caliper, body impedance (3 different devices) and simple anthropometric data (Waist to Hip Ratio [WHR], Body Mass Index [BMI], distance of the aponeurosis of the rectus abdominis muscle to the ventral rim of the abdominal aorta (measured in MRI images on umbilical level) (AD) and subcutaneous adipose tissue thickness at the same level). The different modalities were correlated with the MRI data. RESULTS: : There were highly significant correlations between the skin fold data and TAT (Spearman coefficient 0.668, P >/= 0.0004) and SCAT (0.662, P >/= 0.0004). But there was no correlation with VAT. Impedance data revealed significant correlations of TAT and SCAT (Spearman 0.7, P >/= 0.0004).Simple anthropometric data like waist and hip circumference, WHR, and BMI revealed significant correlations (Spearman coefficient around 0.7-0.4, P < 0.05) with the fat compartments TAT, VAT, and SCAT.The standardized body fat slices and the VAT slices were correlated with the anthropometric data and impedance data to explore specific areas along the body axis where the correlations were higher or weaker. Skinfold data, BMI, and body impedance data yielded significant correlations with TAT along the whole body axis, as well as with VAT in almost the whole analyzed area. However, there was no special body region with locally higher correlations. WHR depicted high correlations with whole VAT, and regional TAT at the abdomen (and not with the other body regions) especially in women. Therefore, it seems to be the best marker for abdominal fat and VAT in this study. CONCLUSIONS: : We compared different body measures and body fat devices with the whole body fat distribution acquired by MRI. Generally, there were significant correlations of all modalities with body fat content (TAT) and mainly with SCAT. Correlations with VAT compartment were much weaker and an adequate estimation of VAT is, therefore, not possible. Only WHR revealed significant correlations with the fat in the body center, but only in women. If it is important to investigate especially the VAT which is responsible for a higher cardiovascular risk, risk for a metabolic syndrome and that is correlated with the course of different psychiatric diseases, cross sectional techniques such as MRI can not be substituted by simpler methods.

Changes of body composition in bulimia nervosa: increased visceral fat and adrenal gland size.

OBJECTIVE: To study the hypothesis that young women suffering from active bulimia nervosa (BN) have more visceral fat and increased adrenal gland volumes (AGV) than healthy controls (HC). METHODS: Thirteen patients with BN of purging type and 11 healthy age and weight matched women (HC), aged between 19 and 36 years (mean 24 +/- 3 years), with a BMI of 19 to 29 (mean 24 +/- SD 3) were examined. BN was diagnosed by DSM-IV criteria and the severity of illness by the Eating Disorder Inventory (EDI-2). Whole body fat distribution and AGV were determined using a whole body magnetic resonance (MR) scan (T1w) and a 3D-sequence (T1w) at 1.5 Tesla. Salivary cortisol was determined at 9 AM and 4 PM. RESULTS: BN patients had significantly more visceral adipose tissue (VAT) (HC, 1589.3 +/- 967.6 ml versus 927.2 +/- 428.4 ml, p < .05) and an increased relative AGV (0.068% of body volume versus 0.048% of body volume, p < .05) compared with HC, although waist circumference and BMI did not differ. Although the VAT part in the upper abdomen was increased, especially the VAT of lower abdomen along with the pelvis or any subcutaneous fat compartment was not increased. CONCLUSIONS: The increase of the VAT volume and the increased AGV in BN women with purging point to chronic high stress levels associated with a hyperactivity of the hypothalamic-pituitary-adrenal axis in these patients. This is the first MR study showing morphological changes in stress associated endocrine organs of young BN patients.

Increase of visceral fat and adrenal gland volume in women with depression: preliminary results of a morphometric MRI study.

OBJECTIVE: Depression is often accompanied by increased visceral adipose tissue (VAT), stress, enlarged adrenal glands, and an increased risk of cardiovascular disease. VAT turn-over is regulated by adrenal stress hormones such as cortisol. Aim of this study was to investigate the relationship between the adrenal volume as a marker for long-term stress and the volume fractions of several body fat compartments in healthy and depressive women. METHODS: Ten depressive and 12 healthy women were investigated. Fat compartments (VAT, VAT in the upper abdomen, subcutaneous adipose tissue (SCAT), and adrenal volume) were measured by MRI. RESULTS: Depressive women revealed more VAT in the upper abdomen than the healthy. There was a significant correlation of age and Body Mass Index (BMI) with the visceral adipose tissue volume and adrenal gland size. In a partial correlation, Beck Depression Inventory (BDI) was correlated with VAT in the upper abdomen (r = 0.45, p < 0.05). CONCLUSIONS: The increase of adrenal volume and VAT and the correlation of BDI with VAT in the upper abdomen support the hypothesis of long-term production of stress hormones in depression. This study is a further step toward describing morphologic substrates of depression in endocrine organs.

Magnetic field distribution in the presence of paramagnetic plates in magnetic resonance imaging: a combined numerical and experimental study.

The amount and geometric distribution of paramagnetic components in tissue is considered as the basis of T2*-weighted magnetic resonance imaging (MRI). Such techniques are routinely applied for assessment of iron in parenchymal organs such as the liver (hemosiderosis). Furthermore, susceptibility sensitive MRI is discussed as an alternative method to x-ray techniques for quantitative assessment of paramagnetic spongy bone components in patients with osteoporosis. The presented work is dedicated to systematically examining the possible influences of macroscopic arrangements of paramagnetic plates on the magnetic field. In a theoretical approach magnetic field distribution was simulated applying decomposition of the plates in single dipoles. Plate size and distances between parallel plates, as well as plate orientation with respect to the static field, were varied for these numerical simulations. Experiments on corresponding plate arrangements were carried out on a 3 T whole body MR scanner using the field-sensitive MR sequence technique for B0 field mapping. Further examinations were carried out on a bone preparation of the femur, where T2* maps were measured and analyzed on a pixel-by-pixel basis at two orientations with respect to the static field. A series of experiments were performed using isotropic and anisotropic volume elements in three-dimensional gradient echo sequences. Resulting magnetic field distributions in the experimentally recorded B0 field maps were in good agreement with the numerical simulations. Field distortions dominated in areas close to the plates and especially near the edges. Those areas showed strong local field gradients, leading to pronounced signal dephasing effects. The examination of the bone preparations revealed different T2* values for identical regions in the bone when the orientation of the bone or the pixel geometry was changed with respect to the magnetic field. Those effects amounted to nearly 70% (22.9 ms versus 13.6 ms in a region of interest in the femur) for 90 degrees rotation of the femur in the magnetic fields. The orientation of anisotropic picture elements with constant size also showed a strong influence on the derived T2* value (up to 80%, increasing with anisotropy of picture elements).

High visceral fat mass and high liver fat are associated with resistance to lifestyle intervention.

OBJECTIVE: High visceral adipose tissue (VAT) and high liver fat (LF) are associated with the metabolic syndrome and diabetes. We studied changes in these two fat depots during weight loss and analyzed whether VAT and LF at baseline predict the response to lifestyle intervention. RESEARCH METHODS AND PROCEDURES: One hundred twelve subjects (48 men and 64 women; age, 46 +/- 11 years; BMI, 29.2 +/- 4.4 kg/m(2)) were studied after a follow up-time of 264 +/- 60 (SD) days. Insulin sensitivity was estimated from the oral glucose tolerance test. Body fat depots were quantified using magnetic resonance imaging and spectroscopy. RESULTS: Cross-sectionally high VAT (r = -0.22, p = 0.02) and high LF (r = -0.36, p < 0.0001) were independently associated with low insulin sensitivity. With intervention, BMI (-3.0%), VAT (-12.0%), and LF (-33.0%) were reduced (all p < 0.001). Insulin sensitivity was improved (+17%, p < 0.01). The changes in BMI (r = -0.41), VAT (r = -0.28), and LF (r = -0.39) were associated with the increase in insulin sensitivity (all p < 0.01). High VAT (r = -0.28, p = 0.01) and high LF (r = -0.38, p < 0.01) at baseline were associated with a lesser increase in insulin sensitivity. DISCUSSION: Baseline values and changes in BMI, VAT, and LF are related to changes in insulin sensitivity during lifestyle intervention. Subjects with high VAT and LF have a lower chance of profiting from lifestyle intervention and may require intensified lifestyle prevention strategies or even pharmacological approaches to improve insulin sensitivity.

Role of proton MR for the study of muscle lipid metabolism.

1H-MR spectroscopy (MRS) of intramyocellular lipids (IMCL) became particularly important when it was recognized that IMCL levels are related to insulin sensitivity. While this relation is rather complex and depends on the training status of the subjects, various other influences such as exercise and diet also influence IMCL concentrations. This may open insight into many metabolic interactions; however, it also requires careful planning of studies in order to control all these confounding influences. This review summarizes various historical, methodological, and practical aspects of 1H-MR spectroscopy (MRS) of muscular lipids. That includes a differentiation of bulk magnetic susceptibility effects and residual dipolar coupling that can both be observed in MRS of skeletal muscle, yet affecting different metabolites in a specific way. Fitting of the intra- (IMCL) and extramyocellular (EMCL) signals with complex line shapes and the transformation into absolute concentrations is discussed. Since the determination of IMCL in muscle groups with oblique fiber orientation or in obese subjects is still difficult, potential improvement with high-resolution spectroscopic imaging or at higher field strength is considered. Fat selective imaging is presented as a possible alternative to MRS and the potential of multinuclear MRS is discussed. 1H-MRS of muscle lipids allows non-invasive and repeated studies of muscle metabolism that lead to highly relevant findings in clinics and patho-physiology.