Subcutaneous fat loss is greater than visceral fat loss with diet and exercise, weight-loss promoting drugs and bariatric surgery: a critical review and meta-analysis

Multi-Functional Polymer Nanoparticles with Enhanced Adipocyte Uptake and Adipocytolytic Efficacy

Multi-functional polymer nanoparticles have been widely utilized to improve cellular uptake and enhance therapeutic efficacy. In this study, it is hypothesized that the cellular uptake of poly(D,L-lactide-co-glycolide) (PLG) nanoparticles loaded with calcium carbonate minerals into adipocytes can be improved by covalent modification with nona-arginine (R9 ) peptide. It is further hypothesized that the internalization mechanism of R9 -modified PLG nanoparticles by adipocytes may be contingent on the concentration of R9 peptide present in the nanoparticles. R9 -modified PLG nanoparticles followed the direct penetration mechanism when the concentration of R9 peptide in the nanoparticles reached 38 µM. Notably, macropinocytosis is the major endocytic mechanism when the R9 peptide concentration is ≤ 26 µM. The endocytic uptake of the nanoparticles effectively generated carbon dioxide gas at an endosomal pH, resulting in significant adipocytolytic effects in vitro, which are further supported by the findings in an obese mouse model induced by high-fat diet. Gas-generating PLG nanoparticles, modified with R9 peptide, demonstrated localized reduction of adipose tissue (reduction of 13.1%) after subcutaneous injection without significant side effects. These findings highlight the potential of multi-functional polymer nanoparticles for the development of effective and targeted fat reduction techniques, addressing both health and cosmetic considerations.

A new approach to quantify visceral fat via bioelectrical impedance analysis and ultrasound compared to MRI

BACKGROUND

Visceral adipose tissue (VAT) has been linked to systemic proinflammatory characteristics, and measuring it accurately usually requires sophisticated instruments. This study aimed to estimate VAT applying a simpler method that uses total subcutaneous fat and total body fat (BF) measurements.

METHOD

As part of our experimental approach, the subcutaneous fat mass (SFT) was measured via US (SFTtotal), and VAT was quantified by assessing MRI data. Both parameters were added to obtain total body fat (BFcalc). Those results were then compared to values obtained from a bioelectrical impedance analysis (BFBIA). Multiple regression analyses were employed to develop a simplified sex-specific equation for SFT, which was subsequently used in conjunction with BFBIA to determine VAT (VATEq).

RESULT

We observed excellent reliability between BFBIA and BFcalc, with no significant difference in body fat values (20.98 ± 8.36 kg vs. 21.08 ± 8.81 kg, p = 0.798, ICC 0.948). VATEq_female/male revealed excellent reliability when compared to VATMRI, and no significant difference appeared (women: 0.03 ± 0.66 kg with a 95% CI ranging from -1.26 kg to 1.32 kg, p = 0.815, ICC: 0.955.; men: -0.01 ± 0.85 kg with a 95% CI ranging from -1.69 kg to 1.66 kg, p = 0.925, ICC: 0.952).

CONCLUSION

Taking an experimental approach, VAT can be determined without MRI.

CT and MR imaging of the properitoneal fat pad: a pictorial essay

The properitoneal fat pad is a distinctive anatomical structure located in the midline of anterior abdominal wall between the transversalis fascia and parietal peritoneum. It has variable size and configuration depending on the gender and nutritional status of individuals, but CT and MR images of the upper abdomen can readily depict its shape and adipose composition. The purpose of this essay is to illustrate the CT and MRI features of normal properitoneal fat pad, and the spectrum of pathological processes that affect it among patients. This information can be relevant to the practicing radiologists and clinicians for the correct diagnosis and management of such conditions because most lesions of this fat pad produce nonspecific symptoms.

Changes in adipose tissue distribution and relation to cardiometabolic risk factors after Roux-en-Y gastric bypass in adolescents

BACKGROUND

Roux-en-Y gastric bypass (RYGB) among adolescents with obesity results in significant weight loss; however, depot-specific changes have been understudied.

OBJECTIVE

We hypothesized that visceral adipose tissue (VAT) reduction in adolescents undergoing RYGB would be greater than other depots and associated with improvement in cardiometabolic risk factors.

SETTING

Three specialized treatment centers in Sweden.

METHODS

Fifty-nine adolescents underwent dual x-ray absorptiometry before surgery and at 1, 2, and 5 years after RYGB. Changes in body composition in multiple depots (total fat, lean body, gynoid fat, android fat, subcutaneous adipose tissue, and VAT) and cardiometabolic risk factors were assessed using multiple linear regression analysis and generalized estimating equations adjusting for age, sex, and baseline risk factor levels. Data are presented as percent change (95% CI) with regression models showing slopes and estimated P values.

RESULTS

At 1 year post-RYGB, a significant reduction was observed across all body composition measures (P < .001) with the greatest reduction observed in VAT (-65.1% [-68.7, -61.8]). From year 1 to 5 years post-RYGB, a regain was observed in all depots except lean body mass (1.2% [.3, 2.7], P = .105). A sex-specific difference in overall trajectories was only observed in lean body mass with males consistently having higher mean levels. Change in VAT at 1 year correlated with change in triglycerides (slope: .21 mg/dL/kg, P = .034) and fasting plasma insulin (slope: 44 pmol/L/kg, P = .027).

CONCLUSIONS

Adiposity measures all decreased after RYGB but poorly predicted change in cardiometabolic risk. Despite significant reductions at 1 year, a steady regain was observed out to 5 years, with values still well below baseline. Further research should consider control group comparison and extended follow-up.

Retrospective analysis of high-intensity focused electromagnetic procedure synchronized with radiofrequency energy for visceral fat reduction

BACKGROUND

Visceral adipose tissue (VAT), present in the abdominal cavity, oftentimes contributes to an unpleasant aesthetic appearance and can be correlated with serious health issues. High-intensity focused electromagnetic field (HIFEM) technology with synchronized radiofrequency (RF) was recently used for abdominal body shaping through subcutaneous fat reduction and muscle growth.

AIM

This study aimed to assess the effect of HIFEM + RF technology on VAT tissue.

METHODS

Data of 16 men and 24 women (22-62 years, 21.2-34.3 kg/cm2 ) from the original study were retrospectively reviewed. All subjects received three 30-min HIFEM + RF abdominal treatments once weekly for three consecutive weeks. The VAT area was measured in the axial plane of MRI scans at two levels: L4-L5 vertebrae and 5 cm above this level. The VAT was identified, segmented, and calculated, yielding total area in square centimeters per scan at both specified levels.

RESULTS

By thoughtful review of the subject's post-treatment MRI scans, no other changes in the abdominal cavity were found except for VAT. The evaluation showed a VAT reduction of 17.8% (p < 0.001) on average at 3-month follow-up, maintaining the results up to 6 months (-17.3%). Averaging the values obtained from both measured levels, the VAT, occupied an area of 100.2 ± 73.3 cm2 at the baseline. At the 3-month follow-up, the subjects achieved an average reduction of 17.9 cm2 , preserving the results at 6 months (-17.6 ± 17.3 cm).

CONCLUSION

This retrospective analysis of MRI images objectively documented the effect of HIFEM + RF abdominal therapy on VAT. The data indicates considerable VAT reduction without serious adverse events following the HIFEM + RF procedure.

The Effects of Ketogenic Diet on Insulin Sensitivity and Weight Loss, Which Came First: The Chicken or the Egg?

The ketogenic diet (KD) is, nowadays, considered an interesting nutritional approach for weight loss and improvement in insulin resistance. Nevertheless, most of the studies available in the literature do not allow a clear distinction between its effects on insulin sensitivity per se, and the effects of weight loss induced by KDs on insulin sensitivity. In this review, we discuss the scientific evidence on the direct and weight loss mediated effects of KDs on glycemic status in humans, describing the KD's biochemical background and the underlying mechanisms.

Exercise Equals the Mobilization of Visceral versus Subcutaneous Adipose Fatty Acid Molecules in Fasted Rats Associated with the Modulation of the AMPK/ATGL/HSL Axis

Combining exercise with fasting is known to boost fat mass-loss, but detailed analysis on the consequential mobilization of visceral and subcutaneous WAT-derived fatty acids has not been performed. In this study, a subset of fasted male rats (66 h) was submitted to daily bouts of mild exercise. Subsequently, by using gas chromatography-flame ionization detection, the content of 22 fatty acids (FA) in visceral (v) versus subcutaneous (sc) white adipose tissue (WAT) depots was compared to those found in response to the separate events. Findings were related to those obtained in serum and liver samples, the latter taking up FA to increase gluconeogenesis and ketogenesis. Each separate intervention reduced scWAT FA content, associated with increased levels of adipose triglyceride lipase (ATGL) protein despite unaltered AMP-activated protein kinase (AMPK) Thr172 phosphorylation, known to induce ATGL expression. The mobility of FAs from vWAT during fasting was absent with the exception of the MUFA 16:1 n-7 and only induced by combining fasting with exercise which was accompanied with reduced hormone sensitive lipase (HSL) Ser563 and increased Ser565 phosphorylation, whereas ATGL protein levels were elevated during fasting in association with the persistently increased phosphorylation of AMPK at Thr172 both during fasting and in response to the combined intervention. As expected, liver FA content increased during fasting, and was not further affected by exercise, despite additional FA release from vWAT in this condition, underlining increased hepatic FA metabolism. Both fasting and its combination with exercise showed preferential hepatic metabolism of the prominent saturated FAs C:16 and C:18 compared to the unsaturated FAs 18:1 n-9 and 18:2 n-6:1. In conclusion, depot-specific differences in WAT fatty acid molecule release during fasting, irrelevant to their degree of saturation or chain length, are mitigated when combined with exercise, to provide fuel to surrounding organs such as the liver which is correlated with increased ATGL/ HSL ratios, involving AMPK only in vWAT.

Hypoxia promotes white adipose tissues browning in rats under simulated environment at altitude of 5000 m

People living in plains tend to decrease in body weight or body fat percentage after entering the plateau. Previous studies have found that plateau animals can burn fat and release calories through white adipose tissues (WATs) browning. However, these studies have focused on the effect of cold stimulation that induced WATs browning while there's hardly study on the effect of hypoxia. In this study, we investigate that whether and how hypoxia contributes to WATs browning in rats from acute to chronic hypoxia. We constructed hypobaric hypoxic rat models by exposing 9-week-old male SD rats to a hypobaric hypoxic chamber for 1, 3, 14 and 28 days (Group H) under simulated environment at altitude of 5000 m. We also established normoxic control groups for each time period (Group C), as well as paired 1-day and 14-day normoxic food-restriction rats that were fed the same amount of food as the hypoxic group ate (Group R). We then observed the growth status of rats and recorded dynamic changes in histologic, cellular and molecular levels of perirenal WATs (PWAT), epididymal WATs (EWAT) and subcutaneous WATs (SWAT) in each group. Results showed that (1) Hypoxic rats had lower food intake, significantly lower body weight than control rats, and showed lower WATs index. (2) In group H14, ASC1 mRNA expressions of PWAT and EWAT in rats were lower than that in group C14, and PAT2 mRNA expression of EWAT was higher than that in both group C14 and R14. In group R14, however, ASC1 mRNA expressions of PWAT and EWAT in rats were higher than both group C14 and H14, and that of SWAT was also significantly higher than group C14. (3) In group H3, both the mRNA and protein levels of uncoupling protein 1 (UCP1) of PWAT in rats were significantly increased than group C3. And in group H14, those of EWAT in rats were significantly increased than group C14. (4) In plasma of rats, norepinephrine (NE) level was significantly increased in group H3 than group C3, and free fatty acids (FFAs) level was significantly increased in group H14 than both group C14 and R14. In group R1, FASN mRNA expressions of PWAT and EWAT in rats were down-regulated than group C1. In group H3, FASN mRNA expressions of PWAT and EWAT in rats were down-regulated while ATGL mRNA expression of EWAT was up-regulated than group C3. Conversely, in group R14, FASN mRNA expressions of PWAT and EWAT in rats were significantly up-regulated than group C14 and H14. These results suggested that hypoxia promoted different WATs browning in rats under simulated environment at altitude of 5000 m and changed the lipid metabolism in WATs. Furthermore, rats in the chronic hypoxic group showed a completely different lipid metabolism of WATs from that in paired food-restriction group.

Obesity, diabetes mellitus, and cardiometabolic risk: An Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) 2023

Background

This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) is intended to provide clinicians an overview of type 2 diabetes mellitus (T2DM), an obesity-related cardiometabolic risk factor.

Methods

The scientific support for this CPS is based upon published citations and clinical perspectives of OMA authors.

Results

Topics include T2DM and obesity as cardiometabolic risk factors, definitions of obesity and adiposopathy, and mechanisms for how obesity causes insulin resistance and beta cell dysfunction. Adipose tissue is an active immune and endocrine organ, whose adiposopathic obesity-mediated dysfunction contributes to metabolic abnormalities often encountered in clinical practice, including hyperglycemia (e.g., pre-diabetes mellitus and T2DM). The determination as to whether adiposopathy ultimately leads to clinical metabolic disease depends on crosstalk interactions and biometabolic responses of non-adipose tissue organs such as liver, muscle, pancreas, kidney, and brain.

Conclusions

This review is intended to assist clinicians in the care of patients with the disease of obesity and T2DM. This CPS provides a simplified overview of how obesity may cause insulin resistance, pre-diabetes, and T2DM. It also provides an algorithmic approach towards treatment of a patient with obesity and T2DM, with "treat obesity first" as a priority. Finally, treatment of obesity and T2DM might best focus upon therapies that not only improve the weight of patients, but also improve the health outcomes of patients (e.g., cardiovascular disease and cancer).

Artificial Neural Network Models for Accurate Predictions of Fat-Free and Fat Masses, Using Easy-to-Measure Anthropometric Parameters

Abdominal fat and fat-free masses report a close association with cardiometabolic risks, therefore this specific body compartment presents more interest than whole-body masses. This research aimed to develop accurate algorithms that predict body masses and specifically trunk fat and fat-free masses from easy to measure parameters in any setting. The study included 104 apparently healthy subjects, but with a higher-than-normal percent of adiposity or waist circumference. Multiple linear regression (MLR) and artificial neural network (ANN) models were built for predicting abdominal fat and fat-free masses in patients with relatively low cardiometabolic risks. The data were divided into training, validation and test sets, and this process was repeated 20 times per each model to reduce the bias of data division on model accuracy. The best performance models used a maximum number of five anthropometric inputs, with higher R² values for ANN models than for MLR models (R² = 0.96-0.98 vs. R² = 0.80-0.94, p = 0.006). The root mean square error (RMSE) for all predicted parameters was significantly lower for ANN models than for MLR models, suggesting a higher accuracy for ANN models. From all body masses predicted, trunk fat mass and fat-free mass registered the best performance with ANN, allowing a possible error of 1.84 kg for predicting the correct trunk fat mass and 1.48 kg for predicting the correct trunk fat-free mass. The developed algorithms represent cost-effective prediction tools for the most relevant adipose and lean tissues involved in the physiopathology of cardiometabolic risks.

Adipocytolytic Polymer Nanoparticles for Localized Fat Reduction

The demand for body fat reduction is increasing. However, conventional lipolytic approaches fail to control adipose tissue reduction and cause severe side effects in adjacent nonadipose tissues. A strategy to specifically reduce subcutaneous fat using adipocytolytic polymer nanoparticles in a minimally invasive manner is reported here. The polymer nanoparticles are designed to generate carbon dioxide gas when selectively absorbed by adipocytes. The carbon dioxide gas generated within late endosomes/lysosomes induces adipocytolysis, thereby reducing the number of cells. Localized injection of the adipocytolytic nanoparticles substantially reduces subcutaneous fat in a high-fat diet-induced obese mouse model, without significant changes in hematological or serum biochemical parameters. The adipocytolytic efficacy of the nanoparticles is also evaluated in a porcine model. This strategy addresses the need to develop safe and effective adipocytolytic agents using functional polymer nanoparticles.

Differences in histomorphology and expression of key lipid regulated genes of four adipose tissues from Tibetan pigs

Tibetan pigs, an indigenous pig breed in China, have high overall fat deposition and flavorful and tasty meat. They are thus good models for studying adipogenesis. Few studies have been conducted focusing on expression of lipid regulated genes in different adipose tissues of Tibetan pigs. Therefore, we compared the difference of histomorphology and expression level of lipid regulated genes through qPCR and western blot in subcutaneous fat, perirenal fat, omental adipose tissue, and inguinal fat of Tibetan pigs. Our results showed that the area of subcutaneous adipocytes in Tibetan pigs was smaller, while the other three adipose tissues (perirenal fat, greater omentum fat, inguinal fat) had cell areas of similar size. The gene expression of FABP4, FASN, FABP3, and ME1 in subcutaneous fat was significantly higher than that in perirenal fat. Furthermore, the protein expression of FABP4 was significantly lower in subcutaneous fat than in perirenal fat (p < 0.05), and the expression of FASN was higher in greater omentum fat than in subcutaneous fat (p = 0.084). The difference in adipocyte cell size and expression of lipid-regulated genes in adipose tissues from the various parts of the pig body is likely due to the different cellular lipid metabolic processes. Specially, FABP4 and FASN may be involved in the regulation of fat deposition in different adipose tissues of Tibetan pigs.

Effect of Weight Regain on Body Composition and Metabolic Biomarkers After Sleeve Gastrectomy: a Cross-Sectional Study from a Hospital Database

INTRODUCTION

Weight regain (WR) is described in approximately 30% of patient's post-bariatric surgery. It is related to the progression or recurrence of associated medical problems and decline in health-related quality of life. This study aimed to test the return of body composition and metabolic biomarkers to pre-operative levels when WR occurs.

METHODS

In this cross-sectional study conducted in 2021, patients were randomly selected from the hospital's electronic databases between 2001 and 2020. Patient demographic data, comorbidities, body compositions, and metabolic biomarkers were collected. Three groups were defined: groups A (WR), B (weight loss), and C (control group; patients with obesity who had not yet undergone bariatric surgery).

RESULTS

A total of 88 patients were enrolled in this study and matched with the control group. The body mass index in group A was 43.8 ± 6.9 kg/m²; group B was 28.6 ± 4.2; group C was 43.9 ± 7.1. Body muscle mass, body fat mass, and visceral fat significantly differed between groups A and B (p < 0.001) but not between groups A and C (p = 0.8). There was a significant difference in leptin, ghrelin, postprandial glucagon-like peptide-1, insulin, and fibroblast growth factor-21 (but not retinol-binding protein-4) between groups A and B. Most metabolic biomarkers in group A returned to the pre-operative values as in group C.

CONCLUSION

WR had a direct negative effect on body composition and metabolic biomarkers, whereby the values returned to pre-operative levels. Early detection of WR and possible additional therapy are necessary to prevent associated medical problems.

The Impact of Exercise Training Intensity on Physiological Adaptations and Insulin Resistance in Women with Abdominal Obesity

Abdominal obesity has emerged globally as a major public health issue due to its high prevalence and morbidity. The benefits of physical exercise among the obese population are well documented. However, the optimal exercise intensity for reducing body fat and preventing insulin resistance and metabolic disorders is still under debate. This study aimed to examine the effects of three different intensities of combined endurance and strength training programs on anthropometric variables, physiological and muscular adaptations, and insulin sensitivity. Forty-three obese young women (age 26.4 ± 4.7 years, BMI 33.1 ± 2.5 kg/m2) were randomly assigned to one of four groups: a control group (G0), a moderate-intensity training group (G50, exercising brisk walking at 50% heart rate reserve HRR), a high-intensity training group (G75, exercise jogging at 75% HRR), and an alternated-intensity training group (G50/75, exercise brisk-walking/jogging at 50−75% HRR) with additional strength training once a week for each group. Body composition, waist circumference (WC), fasting blood glucose, insulin sensitivity and resistance (Homa-IR), resting heart rate (RHR), 6-min walk distance (6MWD), 1-repetition maximum (1-RM), and time to exhaustion (TTE) at 45% and 75% maximal voluntary contraction (MVC) for both the flexor and extensor muscle groups of the knees, were recorded before and after three months of exercise training. All training groups showed significant decreases in body mass, BMI, total body fat, body fat percentage, WC, abdominal and visceral mass (p < 0.001), with a greater reduction of body mass and BMI in G75 (p < 0.05). Lean mass increased significantly only in G50/75 (p < 0.05). The insulin sensitivity and Homa-IR decreased in the three training groups (p < 0.01), with greater enhanced resistance in G50 compared to G75 and G50/75 (p < 0.05). In contrast, there were no pre-post changes in all groups for fasting blood glucose (p > 0.05). 1-RM and TTE of the knee flexor and extensor muscles were improved in the three groups (p < 0.01), with greater improvement in G50/75 for 1RM and G75 in most of the TTE parameters (p < 0.05). RHR decreased and 6MWD increased significantly in the three training groups (p < 0.01), with greater 6MWD improvement in G75 (p < 0.05). In conclusion, the three training intensities seem to generate benefits in terms of body composition, physiological and muscular adaptations, and insulin resistance. High training intensity resulted in greater improvements in body mass, BMI, and endurance and strength, whereas moderate training intensity resulted in greater improvements of insulin resistance and homo-IR. Following alternate-intensity training, greater improvements were observed in lean mass and maximal strength performance.

Effect of host genetics and gut microbiome on fat deposition traits in pigs

Fat deposition affects meat quality, flavor, and production in pigs. Fat deposition is influenced by both genetics and environment. Symbiotic microbe with the host is an important environmental factor to influence fat deposition. In this study, the fat deposition traits were measured in 239 individuals obtained from Tongcheng pigs × Large White pigs resource population. The interactions between genetics and gut microbiome in fat deposition traits were investigated through whole-genome sequencing and cecum microbial 16S ribosomal RNA sequencing. The results showed that the percentage of leaf fat (PL) and intramuscular fat content (IMF) were significantly influenced by host genetics–gut microbiome interaction. The effects of interactions between host genetics and gut microbiome on PL and IMF were 0.13 and 0.29, respectively. The heritability of PL and IMF was estimated as 0.71 and 0.89, respectively. The microbiability of PL and IMF was 0.20 and 0.26, respectively. Microbiome-wide association analysis (MWAS) revealed Anaeroplasma, Paraprevotella, Pasteurella, and Streptococcus were significantly associated with PL, and Sharpea and Helicobacter exhibited significant association with IMF (p &lt; 0.05). Furthermore, Paraprevotella was also identified as a critical microbe affecting PL based on the divergent Wilcoxon rank-sum test. Overall, this study reveals the effect of host genetics and gut microbiome on pig fat deposition traits and provides a new perspective on the genetic improvement of pig fat deposition traits.

Might female patients benefit more from bariatric surgery with respect to inflammation

Background

Bariatric surgery is an effective method for severe obesity and its related comorbidities, in which inflammation plays a crucial role. The aim of this study was to investigate the changes of Neutrophil-to-lymphocyte ratio (NLR) and C-reactive protein (CRP) in patients undergoing laparoscopic sleeve gastrectomy (LSG) and to explore the related factors including gender.

Methods

We retrospectively included 72 patients undergoing LSG in our hospital from 2017 to 2020. Clinical information, laboratory investigations as well as parameters derived from traditional and 2D strain echocardiography were collected. Univariate logistic model was used in myocardial performance index (MPI) and E/E′ analysis. Univariate and Multivariate logistic model were used in NLR analysis.

Results

At baseline, all patients had normal left ventricular ejection fraction (LVEF). The myocardial performance index (MPI) (OR = 1.218 (95%CI 1.040, 1.426); p = 0.0142) and E/E′ (OR = 1.364 (95%CI 1.124, 1.655); p = 0.0017) were independently associated with CRP. LSG led to a significant decrease in inflammatory markers (NLR, 2.4 ± 1.59 vs.1.7 ± 0.86; CRP, 5.6 ± 3.17 vs. 2.1 ± 2.35 mg/L, respectively, both p < 0.001),which was more in NLR among female than male (OR = 3.14 (95%CI 1.112, 8.870); p = 0.031).

Conclusions

The present study indicated a significant correlation between subclinical cardiac dysfunction and CRP among obese patients. Furthermore, female patients might benefit more from bariatric surgery on inflammation.

Effect of aerobic exercise on waist circumference in adults with overweight or obesity: A systematic review and meta-analysis

Excess visceral adiposity contributes to elevated cardiometabolic risk, and waist circumference is commonly used as a surrogate measure of visceral adipose tissue. Although regular aerobic exercise is known to improve abdominal obesity, its effect on waist circumference is unclear. A systematic review and meta-analysis was performed to determine (1) the effect of aerobic exercise on waist circumference in adults with overweight or obesity; (2) the association between any change in waist circumference and change in visceral adipose tissue and/or bodyweight with aerobic exercise interventions; and (3) if reductions in waist circumference with exercise are moderated by clinical characteristics or components of aerobic exercise prescription. Twenty-five randomized controlled trials (1686 participants) were included. Regular aerobic exercise significantly reduced waist circumference by 3.2 cm (95% confidence interval [CI] -3.86, -2.51, p ≤ 0.001) versus control. Change in waist circumference was associated with change in visceral adipose tissue (β = 4.02; 95% CI 1.37, 6.66, p = 0.004), and vigorous intensity produced superior reduction (-4.2 cm, 95% CI -4.99, -3.42, p < 0.0001) in waist circumference compared with moderate intensity (-2.50 cm, 95% CI -3.22, -1.79, p = 0.058). These findings suggest regular aerobic exercise results in modest reductions in waist circumference and associated visceral adipose tissue and that higher intensity exercise may offer superior benefit to moderate intensity.

Utilizing Computed Tomography to Analyze the Morphomic Change between Patients with Localized and Metastatic Renal Cell Carcinoma: Body Composition Varies According to Cancer Stage

Background: This study aimed to elucidate the change of body composition in different clinical stages of renal cell carcinoma (RCC) by analyzing computed tomography (CT) images. Methods: We enrolled patients diagnosed with RCC in a tertiary medical center who did not mention body weight loss or symptoms of cachexia. We grouped patients into those with localized RCC and those with metastatic RCC. Analyses of the volume of skeletal muscles tissue (SMT), subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) calculated based on CT images were performed and included subgroup analyses by sex and age. The correlation between tumor size and body composition in localized RCC was also examined. Results: A total of 188 patients were enrolled in this study. There was significantly lower VAT (p = 0.015) in the metastatic group than in the localized group. SAT, body weight, and body mass index (BMI) were not significantly different between these two groups. In the subgroup analysis, a significant difference in SMT and VAT was noted in the male and younger subgroups but not in the female and older subgroups. Regarding primary tumor size in localized RCC, VAT was significantly higher in patients with larger tumors (p = 0.003). Conclusions: In localized RCC, VAT volume was significantly larger in those with large primary tumor size. However, the VAT was significantly lower in those with metastatic status comparing to those with localized disease. The clinical course of cancers closely correlates with body composition.

Obesity-associated Blunted Subcutaneous Adipose Tissue Blood Flow After Meal Improves After Bariatric Surgery

CONTEXT

Glucose-dependent insulinotropic peptide (GIP) and meal ingestion increase subcutaneous adipose tissue (SAT) perfusion in healthy individuals. The effects of GIP and a meal on visceral adipose tissue (VAT) perfusion are unclear.

OBJECTIVE

Our aim was to investigate the effects of meal and GIP on VAT and SAT perfusion in obese individuals with type 2 diabetes mellitus (T2DM) before and after bariatric surgery.

METHODS

We recruited 10 obese individuals with T2DM scheduled for bariatric surgery and 10 control individuals. Participants were studied under 2 stimulations: meal ingestion and GIP infusion. SAT and VAT perfusion was measured using 15O-H2O positron emission tomography-magnetic resonance imaging at 3 time points: baseline, 20 minutes, and 50 minutes after the start of stimulation. Obese individuals were studied before and after bariatric surgery.

RESULTS

Before bariatric surgery the responses of SAT perfusion to meal (P = .04) and GIP-infusion (P = .002) were blunted in the obese participants compared to controls. VAT perfusion response did not differ between obese and control individuals after a meal or GIP infusion. After bariatric surgery SAT perfusion response to a meal was similar to that of controls. SAT perfusion response to GIP administration remained lower in the operated-on than control participants. There was no change in VAT perfusion response after bariatric surgery.

CONCLUSION

The vasodilating effects of GIP and meal are blunted in SAT but not in VAT in obese individuals with T2DM. Bariatric surgery improves the effects of a meal on SAT perfusion, but not the effects of GIP. Postprandial increase in SAT perfusion after bariatric surgery seems to be regulated in a GIP-independent manner.

The interaction between Alternative Healthy Eating Index and MC4R rs17782313 gene variants on central and general obesity indices in women: a cross-sectional study

BACKGROUND

Previous studies have shown that the C allele of melanocortin 4 receptor (MC4R) rs17782313 and Alternative Healthy Eating Index (AHEI) are separately associated with obesity. However, no study has assessed the aim of this study which is to investigate the interaction between MC4R rs17782313 variants and AHEI and their association with central and general obesity indices.

METHODS

A total of 291 women with BMI ≥25 and aged 18-48 years enrolled in this cross-sectional study. All participants were assessed for body composition, anthropometric measures, dietary intake, and blood parameters. After obtaining data of dietary intake from the 147-item food frequency questionnaire (FFQ) the AHEI was calculated. MC4R rs17782313 SNPs were assessed using the restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

After adjustment for age, energy intake, physical activity, marital and economic status, the interaction between MC4R rs17782313 and AHEI was associated with hip circumference (HC) (β=-0.41, 95%CI: -0.77 to -0.05, P=0.02), body mass index (BMI) (β=-0.15, 95%CI: -0.29 to -0.02, P=0.02), fat mass (kg) (β=-0.28, 95%CI: -0.56 to -0.01, P=0.03), Visceral fat area (VFA) (β=-5.68, 95%CI: -9.55 to -1.80, P=0.004). The other measures that seem to be suggestively related to this interaction (0.05< P <0.07) are waist circumference (WC), waist-to-height ratio (WHtR), trunk fat (TF) (%), TF (kg), fat mass (%), and fat mass index (FMI).

CONCLUSION

Interaction between MC4R rs17782313 and AHEI can be related to some central and general obesity indices in overweight/obese women. This article is protected by copyright. All rights reserved.

Overweight, Obesity, and CVD Risk: a Focus on Visceral/Ectopic Fat

PURPOSE OF REVIEW

Despite its prevalence and well-documented impact on population health, obesity has not emerged as a strong independent risk factor for cardiovascular disease after control for intermediate risk factors. The purpose of this brief narrative review is to highlight results from imaging studies that have not only documented the remarkable heterogeneity of body fat topography but also the importance of visceral adiposity as a key body fat depot associated with cardiovascular disease risk and type 2 diabetes.

RECENT FINDINGS

Simple tools are also discussed in order to refine cardiometabolic risk assessment in persons with overweight/obesity. It is proposed that four lifestyle vital signs should be considered in clinical practice to improve discrimination of health risk in individuals with overweight/obesity: waist circumference as a simple marker of abdominal adiposity, cardiorespiratory fitness, overall diet quality, and level of reported physical activity. Heterogeneity of obesity is proposed as an example of a condition that would benefit from a precision lifestyle medicine approach.

Adipose-tissue plasticity in health and disease

Adipose tissue, colloquially known as "fat," is an extraordinarily flexible and heterogeneous organ. While historically viewed as a passive site for energy storage, we now appreciate that adipose tissue regulates many aspects of whole-body physiology, including food intake, maintenance of energy levels, insulin sensitivity, body temperature, and immune responses. A crucial property of adipose tissue is its high degree of plasticity. Physiologic stimuli induce dramatic alterations in adipose-tissue metabolism, structure, and phenotype to meet the needs of the organism. Limitations to this plasticity cause diminished or aberrant responses to physiologic cues and drive the progression of cardiometabolic disease along with other pathological consequences of obesity.

Comparisons of calorie restriction and structured exercise on reductions in visceral and abdominal subcutaneous adipose tissue: a systematic review

Exercise and low-calorie diets are common approaches taken to produce an energy deficit for weight loss in obesity. Changes in visceral and abdominal subcutaneous fat associated with weight loss are important questions but have not yet been concluded. We investigated the relationship between changes in visceral (VAT) and subcutaneous adipose tissue (SAT) areas obtained by abdominal imaging with the change in total body fat. The relevant databases were searched through January 2021 according to the PRISMA guidelines. Sixty-five studies were included. We found that the change in total body fat was associated with changes in both VAT and abdominal SAT areas, but the relationship between total body fat and the abdominal SAT area appeared stronger. Baseline values of VAT and abdominal SAT area were similar in the three treatment groups (calorie restriction, calorie restriction plus exercise, and exercise alone). The reduction in abdominal SAT area for a loss of 1 kg of total body fat was about 10 cm², which was similar among all the treatments. The change in VAT area (-26.3 cm²) was a similar level as the change in abdominal SAT area (-31.5 cm²) in the exercise, whereas in the calorie restriction with and without exercise, the change in VAT area (-33.6 and -51.6 cm², respectively) was approximately half of the reduction of SAT area (-65.1 and -87.2 cm², respectively). Absolute changes in VAT and abdominal SAT areas might differ between interventions for the exercise and calorie restriction with and without exercise.

Multiprofessional intervention and telenursing in the treatment of obese people in the COVID-19 pandemic: a pragmatic clinical trial

ABSTRACT Objectives: to analyze the effects of a multiprofessional remote intervention and telenursing in the treatment of obesity. Methods: pragmatic clinical trial of intervention, conducted with obese adults. The multiprofessional remote intervention with a nurse occurred for 16 weeks through a messaging application. The application analyzed body composition, hemodynamic and laboratory variables, comparing the results obtained with the group that participated in face-to-face multiprofessional intervention without a nurse. The study investigated the effects of the intervention comparing the intervention groups and the moments through the ANOVA test for repeated measures. Results: Group 1 obtained significance in the variables: percentage of body fat (p = 0.008); blood glucose (p = 0.014); insulin (p = 0.001); abdominal and waist circumference; and HDL cholesterol (p = 0.000). Conclusions: the effects of multiprofessional remote intervention and telenursing significantly decreased the risk variables for metabolic syndrome in the treatment of obesity.

Metabolic Effects on Body Components After a Three-Month Physical Intervention in Overweight Medical Staff

Purpose

This study analyzes the metabolic effects on body components of short-term standard physical training interventions in the staff of a Chinese hospital.

Methods and materials

We analyzed annual medical examinations, including blood sampling, ultrasound examinations, etc., and selected 10 overweight voluntary participants to take part in formal physical training, and a body composition analyzer DBA-550 (Donghuayuan Medical Co., Ltd, Beijing, China) was used to analyze body components' change before physical training interventions and the first month and third month after the physical intervention.

Results

The intervention significantly decreased body mass index (BMI) (p<0.05). Plasma lipids, triglyceride, and waist/hip ratio in females, trunk circumference in males, and limb circumference in females changed significantly (p<0.05). The body composition analysis showed that alterations in lean mass, fat weight, and fat percentage were not significant. Moreover, the segmental skeletal weight stable and segmental edema indices changed significantly but were within the normal range.

Conclusions

Three months of short-term physical intervention effectively lower body weight and fat, but more significant changes in long-term intervention and larger groups can be expected. Besides, the body composition analyzer proved reliable and can modify more individualized treatment plans for overweight and obese individuals.

Body Composition, Basal Metabolic Rate and Leptin in Long-Term Weight Regain After Roux-en-Y Gastric Bypass Are Similar to Pre-surgical Obesity

PURPOSE

The purpose of this study is to evaluate the relationship between body composition, basal metabolic rate (BMR), and serum concentrations of leptin with long-term weight regain after Roux-en-Y gastric bypass (RYGB) and compare it with obesity before surgery.

MATERIALS AND METHODS

Prospective longitudinal analytical study. Three groups were formed: individuals 60 months post RYGB, with weight regain (G1) and without it (G2), and individuals with obesity who had not undergone bariatric surgery (G3). Body fat (BF), body fat mass (BFM), visceral fat (VF), fat-free mass (FFM), skeletal muscle mass (SMM), and BMR were assessed by octapolar and multi-frequency electrical bioimpedance. Fasting serum concentrations of leptin were measured.

RESULTS

Seventy-two individuals were included, 24 in each group. Higher means of BF, BFM, VF, and leptin levels were observed in G1, when compared to G2 (BF: 47.5 ± 5.6 vs. 32.0 ± 8.0, p < 0.05; FBM: 47.8 ± 11.6 vs. 23.9 ± 7.0, p < 0.05; VF: 156.8 ± 30.2 vs. 96.1 ± 23.8, p < 0.05; leptin: 45,251.2 pg/mL ± 20,071.8 vs. 11,525.7 pg/mL ± 9177.5, p < 0.000). G1 and G2 did not differ in FFM, SMM, and BMR. G1 and G3 were similar according to BF, FFM, BMR, and leptin levels. Body composition, but not leptin, was correlated with %weight regain in G1 (FBM: r = 0.666, p < 0.000; BF: r = 0.428, p = 0.037; VF: r = 0.544, p = 0.006).

CONCLUSION

Long-term weight regain after RYGB is similar to pre-surgical obesity in body composition, BMR, and leptin concentrations, indicating relapse of metabolic and hormonal impairments associated with excessive body fat.

Protein supplementation during an energy-restricted diet induces visceral fat loss and gut microbiota amino acid metabolism activation: a randomized trial

Interactions between diet and gut microbiota are critical regulators of energy metabolism. The effects of fibre intake have been deeply studied but little is known about the impact of proteins. Here, we investigated the effects of high protein supplementation (Investigational Product, IP) in a double blind, randomised placebo-controled intervention study (NCT01755104) where 107 participants received the IP or an isocaloric normoproteic comparator (CP) alongside a mild caloric restriction. Gut microbiota profiles were explored in a patient subset (n = 53) using shotgun metagenomic sequencing. Visceral fat decreased in both groups (IP group: − 20.8 ± 23.2 cm²; CP group: − 14.5 ± 24.3 cm²) with a greater reduction (p < 0.05) with the IP supplementation in the Per Protocol population. Microbial diversity increased in individuals with a baseline low gene count (p < 0.05). The decrease in weight, fat mass and visceral fat mass significantly correlated with the increase in microbial diversity (p < 0.05). Protein supplementation had little effects on bacteria composition but major differences were seen at functional level. Protein supplementation stimulated bacterial amino acid metabolism (90% amino-acid synthesis functions enriched with IP versus 13% in CP group (p < 0.01)). Protein supplementation alongside a mild energy restriction induces visceral fat mass loss and an activation of gut microbiota amino-acid metabolism.

Clinical trial registration: NCT01755104 (24/12/2012). https://clinicaltrials.gov/ct2/show/record/NCT01755104?term=NCT01755104&draw=2&rank=1.

Identification of TBX15 as an adipose master trans regulator of abdominal obesity genes

Background

Obesity predisposes individuals to multiple cardiometabolic disorders, including type 2 diabetes (T2D). As body mass index (BMI) cannot reliably differentiate fat from lean mass, the metabolically detrimental abdominal obesity has been estimated using waist-hip ratio (WHR). Waist-hip ratio adjusted for body mass index (WHRadjBMI) in turn is a well-established sex-specific marker for abdominal fat and adiposity, and a predictor of adverse metabolic outcomes, such as T2D. However, the underlying genes and regulatory mechanisms orchestrating the sex differences in obesity and body fat distribution in humans are not well understood.

Methods

We searched for genetic master regulators of WHRadjBMI by employing integrative genomics approaches on human subcutaneous adipose RNA sequencing (RNA-seq) data (n ~ 1400) and WHRadjBMI GWAS data (n ~ 700,000) from the WHRadjBMI GWAS cohorts and the UK Biobank (UKB), using co-expression network, transcriptome-wide association study (TWAS), and polygenic risk score (PRS) approaches. Finally, we functionally verified our genomic results using gene knockdown experiments in a human primary cell type that is critical for adipose tissue function.

Results

Here, we identified an adipose gene co-expression network that contains 35 obesity GWAS genes and explains a significant amount of polygenic risk for abdominal obesity and T2D in the UKB (n = 392,551) in a sex-dependent way. We showed that this network is preserved in the adipose tissue data from the Finnish Kuopio Obesity Study and Mexican Obesity Study. The network is controlled by a novel adipose master transcription factor (TF), TBX15, a WHRadjBMI GWAS gene that regulates the network in trans. Knockdown of TBX15 in human primary preadipocytes resulted in changes in expression of 130 network genes, including the key adipose TFs, PPARG and KLF15, which were significantly impacted (FDR < 0.05), thus functionally verifying the trans regulatory effect of TBX15 on the WHRadjBMI co-expression network.

Conclusions

Our study discovers a novel key function for the TBX15 TF in trans regulating an adipose co-expression network of 347 adipose, mitochondrial, and metabolically important genes, including PPARG, KLF15, PPARA, ADIPOQ, and 35 obesity GWAS genes. Thus, based on our converging genomic, transcriptional, and functional evidence, we interpret the role of TBX15 to be a main transcriptional regulator in the adipose tissue and discover its importance in human abdominal obesity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13073-021-00939-2.

Dose-response effects of aerobic exercise on adiposity markers in postmenopausal women: pooled analyses from two randomized controlled trials

BACKGROUND/OBJECTIVE

Exercise may reduce the risk of breast cancer through adiposity changes, but the dose-response effects of exercise volume on adiposity markers are unknown in postmenopausal women. We aimed to compare the dose-response effects of prescribed aerobic exercise volume on adiposity outcomes.

PARTICIPANTS/METHODS

Data from the Alberta Physical Activity and Breast Cancer Prevention (ALPHA) and Breast Cancer and Exercise Trial in Alberta (BETA) were pooled for this analysis (N = 720). These were 12-month randomized controlled trials, where participants were randomized to 225 min/week (mid-volume) of aerobic exercise versus usual inactive lifestyle (ALPHA), or 150 min/week (low-volume) versus 300 min/week (high-volume) (BETA). Fat mass and fat-free mass were measured using DXA and intra-abdominal and subcutaneous fat area were assessed with computed tomography.

RESULTS

After 12 months of aerobic exercise, increasing exercise volumes from no exercise/control to 300 min/week resulted in statistically significant reductions in BMI, weight, fat mass, fat percentage, intra-abdominal and subcutaneous fat area (P < 0.001). Compared with controls, fat mass loss was -1.13, -1.98 and -2.09 kg in the low-, mid- and high-volume groups, respectively. Similarly, weight loss was -1.47, -1.83, -2.21 kg in the low-, mid- and high-volume groups, respectively, compared to controls, and intra-abdominal fat area loss was -7.44, -15.56 and -8.76 cm² in the low-, mid- and high-volume groups, respectively, compared to controls. No evidence for a dose-response effect on fat-free mass was noted.

CONCLUSION

A dose-response effect of exercise volume on adiposity markers was noted, however, the differences in adiposity markers were smaller when comparing 225 min/week to 300 min/week of exercise. Given the strong positive associations between obesity and postmenopausal breast cancer risk, this study provides evidence on the importance of exercise volume as part of the exercise prescription to reduce adiposity and, ultimately, postmenopausal breast cancer risk.

Roux-en-Y Gastric Bypass for T2D Treatment in Chinese Patients with Low BMI: 5-Year Outcomes

BACKGROUND

RYGB was considered as an effective treatment for obese patients with T2D. However, 5-year outcomes including T2D remission after surgery have not been adequately studied in Chinese patients.

OBJECTIVES

Our aim is to evaluate metabolic outcomes of RYGB in 5-year follow-up.

METHODS

We retrospectively divided 59 Chinese patients into two groups, namely BMI groups (group A: BMI < 28 kg/m²; group B: BMI ≥ 28 kg/m²) and A1C groups (group C: A1C < 7%; group D: A1C ≥ 7%). Their medical records were collected and cardiovascular risk and medications were evaluated in 5 years after RYGB.

RESULTS

Thirty patients were female (30/59, 50.85%). RYGB was performed laparoscopically without mortality or major complications. The mean BMI in 59 patients decreased from 30.89 ± 3.12 to 25.04 ± 3.48 in the fifth year. No one was lost to follow-up in 5 years. There were significant reductions in BMI, A1C, and oral medication or insulin in all groups. Diabetes remission rates in the first, third, and fifth years postoperation were 77.97, 61.02, and 49.15%. T2D relapse and requirement for antihypertensive agents increased in the third and fifth years. Larger quantity of subcutaneous fat area (SFA) and shorter duration of T2D preoperation were more likely to achieve remission of T2D postoperation.

CONCLUSIONS

This study has confirmed that RYGB is an effective treatment for obese Chinese patients with T2D, resulting in diabetes remission, metabolic disorder control, and cardiovascular risk reduction.

The Influence of Laparoscopic Sleeve Gastrectomy on Body Composition and Fat Distribution in Obese Caucasian Men and Women

Background

The aim of the study was to assess changes in body composition in patients subjected to laparoscopic sleeve gastrectomy (LSG).

Methods

Changes in body composition following LSG were determined in a group of 155 patients with obesity (117 women and 38 men), with dual-energy X-ray absorptiometry (DXA). Whole body fat mass (FM) and lean body mass (LBM) were determined, and abdominal fat mass (AbdF) was assessed within the region extending from the top of the pubic bone up to the line between 12th thoracic and 1st lumbar vertebras.

Results

Over the period of 12 months following LSG, body mass index decreased by 28.2 ± 9.0% (p < 0.001). The reduction of body weight by 35.4 ± 12.6 kg (p < 0.001) was the result of a decrease in FM by 23.9 ± 8.9 kg (p < 0.001) and LBM by 10.5 ± 3.8 kg (p < 0.001). AbdF decreased from 13.2 ± 3.1 to 8.2 ± 2.7 kg (p < 0.001), but abdominal fat to total fat mass ratio increased from 24.9 ± 4.7 to 28.0 ± 5.8% (p < 0.001). The loss of AbdF was more pronounced in men than in women. The rate of FM loss was attenuated with patients’ age.

Conclusions

Over the period of 12 months following LSG, the reduction of FM was more than twice as much as decrease of LBM. The loss of AbdF was slower than a loss of peripheral subcutaneous fat.

Population Diversity Challenge the External Validity of the European Randomized Controlled Trials Comparing Laparoscopic Gastric Bypass and Sleeve Gastrectomy

INTRODUCTION

Two randomized controlled trials (RCTs) from Europe recently showed similar weight loss and rates of type 2 diabetes (T2D) remission following laparoscopic gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG). However, results from observational studies in the United States (US) have discordant results. We compared 1-year weight loss and T2D remission between LRYGB and LSG in a heterogeneous patient cohort from the US, albeit with similar inclusion and exclusion criteria to the European RCTs.

METHODS

Logistic regression was used to propensity match LSG and LRYGB patients according to age, gender, race, preoperative BMI, and T2D. Inclusion and exclusion criteria were adopted from the two European RCTs. Demographic, anthropometric, weight outcomes, and comorbidities prevalence were compared at baseline and 1-year follow-up.

RESULTS

We included 278 patients (139 LSG and 139 RYGB; median age 42 years, 89% female, 57% black race, 22% with public health insurance, and 25% with T2D). One year after surgery, mean %EWL was 77.3 ± 19.5% with LRYGB and 63.1 ± 21% with LSG (P < 0.001). Mean %TWL was 34.2 ± 7.3% after LRYGB and 28.1 ± 8.2% after LSG, (P < 0.001). The proportion of patients who achieved T2D remission was comparable between surgeries (LRGYB: 68.6% vs. LSG: 66.7%, P = 0.89). LSG, older age, black race, and higher preoperative BMI were independently associated with lower %EWL. Independent correlates of weight loss were different for LRYGB and LSG.

CONCLUSIONS

Weight loss, but not the likelihood of T2D remission, was greater with LRYGB than LSG in a diverse patient cohort in the US. Further research efforts connecting population diversity to discordant results across studies is needed to better counsel patients with regards to expected postoperative outcomes.

Role of Imaging in Bariatric Surgery: A Review of the Various Surgical Techniques and Their Complications

According to the World Health Organization, obesity has reached epidemic proportions globally, with at least 2.8 million people dying each year as a result of being overweight or obese. Bariatric surgery is being increasingly used as a form of treatment, particularly in those patients where lifestyle modifications are deemed insufficient. With the role of radiologists transitioning from a medical to a surgical evaluation in obesity, it is becoming increasingly important to familiarize oneself with the various imaging techniques used in the preoperative and postsurgical evaluation in such cases. This article aims to review the various surgeries performed, their normal imaging appearance, and the various complications that could be encountered.

The effect of high-intensity focused electromagnetic procedure on visceral adipose tissue: Retrospective assessment of computed tomography scans

BACKGROUND

High levels of visceral adipose tissue (VAT) are associated with abdominal obesity and increased risk of metabolic deterioration. Recent studies showed that intensive physical exercise results in the reduction of subcutaneous and visceral fat.

AIMS

This study investigates the effect of supramaximal muscle contractions induced by a HIFEM procedure for abdominal VAT changes.

METHODS

Computed tomography (CT) scans of 22 subjects (47.3 ± 8.4 years, BMI of 23.5 ± 3.5 kg/m² ) who received 8 HIFEM treatments of the abdomen (2-3 days apart) were retrospectively evaluated for the changes in VAT. The CT scans were obtained at baseline and 1 month after the last treatment. The transverse slices at umbilical, infraumbilical, and supraumbilical levels were used to determine the cross-sectional area (CSA) of VAT through a semi-automated segmentation method.

RESULTS

Analysis of the CSA revealed a significant (P = .004) and uniform reduction of the abdominal VAT area by 14.3% (-16.7 cm² ) from 110.6 ± 69.0 cm² to 93.9 ± 54.6 cm² . In general, a higher relative improvement was seen infraumbilically (17.1%), followed by supraumbilical (15.5%) and umbilical (10.7%) levels. The reduction of VAT was strongly correlated to the reduction of subcutaneous fat (r(17) = 0.66; P = .002). A decrease in VAT volume contributed to the overall aesthetic enhancement visible on digital photographs.

CONCLUSIONS

The outcomes indicate that HIFEM technology has a positive effect on VAT. However, further studies are necessary to validate these outcomes and to clarify the exact mechanism of a VAT reduction. Based on our results, the HIFEM procedure may be a beneficial treatment option for patients with high VAT deposits.

Decrease of dipeptidyl peptidase 4 activity is associated with weight loss after bariatric surgery

Purpose

Dipeptidyl peptidase 4 (DPP4) is expressed and secreted by adipocytes. DPP4 induces insulin resistance independently of its effect on glucagon-like peptide 1, thus it is conceivable that DPP4 directly contributes to metabolic dysfunction in patients with morbid obesity. The aim of this study was to investigate the impact of weight loss induced by bariatric surgery on DPP4 activity, and whether these changes are associated with improvements in markers of metabolic dysfunction and fatty liver disease.

Materials and Methods

We included 68 non-diabetic patients who underwent bariatric surgery. Serum DPP4 activity was measured using a fluorogenic substrate before and after surgery.

Results

Results: After a median follow-up period of 12 (IQR 11-17) months, median serum DPP4 activity decreased from 230 (IQR: 194-273) to 193 (164-252) pmol/min (p=0.012). The decrease in DPP4 activity was significantly correlated with decreases in BMI, improved cholesterol levels, reduced hepatic injury markers as well as improved post-prandial insulin sensitivity. After multivariable adjustment, ΔDPP4 activity remained significantly associated with Δcholesterol (beta=0.341, p=0.025), ΔLDL cholesterol (beta=0.350, p=0.019), Δgamma-glutamyltransferase (beta=0.323, p=0.040) and ΔMatsuda index (beta=-0.386, p=0.045).

Conclusion

We demonstrated that weight loss induced by bariatric surgery results in decreased circulating DPP4 activity beyond the initial phase of weight loss. The associations between decreased DPP4 activity and improved cholesterol levels as well as hepatic injury markers point towards pleiotropic effects of DPP4 beyond glucose metabolism which warrant further investigation.

The effect of the magnitude of weight loss on non-alcoholic fatty liver disease: A systematic review and meta-analysis

BACKGROUND

Trials show that weight loss interventions improve biomarkers of non-alcoholic fatty liver disease (NAFLD), but it is unclear if a dose-response relationship exists.

OBJECTIVE

We aimed to quantify the dose-response relationship between the magnitude of weight loss and improvements in NAFLD.

METHODS

Nine databases and trial registries were searched until October 2020. Single-arm, non-randomized comparative, or randomized trials of weight loss interventions (behavioral weight loss programs [BWLPs], pharmacotherapy, or bariatric surgery) in people with NAFLD were eligible for inclusion if they reported an association between changes in weight and changes in blood, radiological, or histological biomarkers of liver disease. The review followed Cochrane methods and the risk of bias was assessed using the Newcastle-Ottawa scale. Pooled unstandardized b coefficients were calculated using random-effect meta-analyses.

RESULTS

Forty-three studies (BWMPs: 26, pharmacotherapy: 9, surgery: 8) with 2809 participants were included. The median follow-up was 6 (interquartile range: 6) months. The direction of effect was generally consistent but the estimates imprecise. Every 1 kg of weight lost was associated with a 0.83-unit (95% CI: 0.53 to 1.14, p < 0.0001, I² = 92%, n = 18) reduction in alanine aminotransferase (U/L), a 0.56-unit (95% CI: 0.32 to 0.79, p < 0.0001, I² = 68%, n = 11) reduction in aspartate transaminase (U/L), and a 0.77 percentage point (95% CI: 0.51 to 1.03, p < 0.0001, I² = 72%, n = 11) reduction in steatosis assessed by radiology or histology. There was evidence of a dose-response relationship with liver inflammation, ballooning, and resolution of NAFLD or NASH, but limited evidence of a dose-response relationship with fibrosis or NAFLD activity score. On average, the risk of bias for selection and outcome was medium and low, respectively.

CONCLUSION

Clinically significant improvements in NAFLD are achieved even with modest weight loss, but greater weight loss is associated with greater improvements. Embedding support for formal weight loss programs as part of the care pathway for the treatment of NAFLD could reduce the burden of disease.

PROSPERO

CRD42018093676.

Lipophagy: A New Perspective of Natural Products in Type 2 Diabetes Mellitus Treatment

Autophagy has been reported to involve in the pathogenesis of type 2 diabetes mellitus (T2DM), which protects the insulin target tissues and pancreatic β-cells. However, autophagy is inhibited when the cells are lipid overload. That, in turn, increases the accumulation of fat. Lipotoxicity caused by excessive lipid accumulation contributes to pathogenesis of T2DM. Therefore, it is undeniable to break the vicious circles between lipid excess and autophagy deficiency. Lipophagy, a selective form of autophagy, is characterized by selective breakdown of lipid droplets (LDs). The nutritional status of cells contributes to the way of autophagy (selective or non-selective), while selective autophagy helps to accurately remove excess substances. It seems that lipophagy could be an effective means to decrease abnormal lipid accumulation that leads to insulin resistance and β-cell impairment by removing ectopic LDs. Based on this process, many natural compounds have been reported to decrease lipid accumulation in tissues through autophagy-lysosomal pathway, which gradually highlights the significance of lipophagy. In this review, we focus on the mechanisms that lipophagy improves T2DM and natural products that are applied to induce lipophagy. It is also suggested that natural herbs with rich contents of natural products inducing lipophagy would be potential candidates for alleviating T2DM.

Correlation of Telomere Length in Adipose Tissue and Leukocytes and its Association with Postsurgical Weight Loss

OBJECTIVE

The aim of this study was to determine the relationship between telomere length (TL) in subcutaneous adipose tissue (SAT), visceral adipose tissues (VAT), and leukocytes, as well as to examine the associations of TL in these tissues with postsurgical weight loss in Asians with severe obesity.

METHODS

Presurgery TL was measured in leukocytes, SAT, and VAT of 91 patients who underwent weight loss surgery. Correlation between TL in multiple tissues was assessed using Pearson correlation. The association of presurgery TL and postsurgical weight loss at 6 or 12 months, expressed as a percentage of weight loss, was determined using linear regression in 70 patients.

RESULTS

Telomeres were longer in VAT compared with those in leukocytes and SAT (P < 0.001) but were highly correlated between tissues. The strongest correlation was observed between TL in VAT and leukocytes (r = 0.739, P = 6.22 × 10^-17 ). Compared with individuals in the highest tertile, those in the lowest tertile of VAT TL showed greater weight loss (β = 6.23, SE = 3.10, P = 0.044) independent of age, sex, ethnicity, types of surgery, diabetes condition, preoperative BMI, and follow-up period.

CONCLUSIONS

Among patients with severe obesity, TL in leukocytes and adipose tissue was highly correlated. However, there was variability in the association of TL in these tissues with weight loss after surgery.

Change in abdominal, but not femoral subcutaneous fat CT-radiodensity is associated with improved metabolic profile after bariatric surgery

BACKGROUND AND AIMS

Computed tomography (CT)-derived adipose tissue radiodensity represents a potential noninvasive surrogate marker for lipid deposition and obesity-related metabolic disease risk. We studied the effects of bariatric surgery on CT-derived adipose radiodensities in abdominal and femoral areas and their relationships to circulating metabolites in morbidly obese patients.

METHODS AND RESULTS

We examined 23 morbidly obese women who underwent CT imaging before and 6 months after bariatric surgery. Fifteen healthy non-obese women served as controls. Radiodensities of the abdominal subcutaneous (SAT) and visceral adipose tissue (VAT), and the femoral SAT, adipose tissue masses were measured in all participants. Circulating metabolites were measured by NMR. At baseline, radiodensities of abdominal fat depots were lower in the obese patients as compared to the controls. Surprisingly, radiodensity of femoral SAT was higher in the obese as compared to the controls. In the abdominal SAT depot, radiodensity strongly correlated with SAT mass (r = -0.72, p < 0.001). After surgery, the radiodensities of abdominal fat increased significantly (both p < 0.01), while femoral SAT radiodensity remained unchanged. Circulating ApoB/ApoA-I, leucine, valine, and GlycA decreased, while glycine levels significantly increased as compared to pre-surgical values (all p < 0.05). The increase in abdominal fat radiodensity correlated negatively with the decreased levels of ApoB/ApoA-I ratio, leucine and GlycA (all p < 0.05). The increase in abdominal SAT density was significantly correlated with the decrease in the fat depot mass (r = -0.66, p = 0.002).

CONCLUSION

Higher lipid content in abdominal fat depots, and lower content in femoral subcutaneous fat, constitute prominent pathophysiological features in morbid obesity. Further studies are needed to clarify the role of non-abdominal subcutaneous fat in the pathogenesis of obesity.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01373892.

Low-carbohydrate diets: Effects on metabolism and exercise - A comprehensive literature review

BACKGROUND & AIMS

Low-carbohydrate diets (LCD) have gained substantial attention in recent years for their potential in health promotion and treatment of diseases, but they remain controversial in nutrition guidelines and exercise performance. Herein, through a literature review, we discuss the current evidence base by considering management of LCD and potential coupling of these dietary regiments with physical exercise.

METHODS

We performed a comprehensive literature review with no date limits as a means of including seminal to current studies.

RESULTS

Reduction of CHO intake decreases muscle glycogen, yielding greater fat oxidation and associated metabolic benefits. LCD may promote fat mass loss and regulation of biochemical parameters, such as lipid and glycemic biomarkers. The therapeutic potential of LCD towards noncommunicable diseases, particularly obesity and its comorbidities, is therefore reasonable as a dietary candidate in this context. Potential benefits to this approach are linked to enhancement of mitochondrial gene expression and mitochondrial biogenesis. As such, LCD may be a feasible tool in a 'periodized nutrition' for athletes and within clinical scenarios. Long-term observational follow-up studies have demonstrated increased mortality and cardiovascular implications of LCD. However, harmful associations may depend on the food source (e.g., animal-based vs. plant-based foods).

CONCLUSION

LCD may decrease body mass, waist circumference, and improve fat and carbohydrate metabolism. When combined with exercise, LCD seems to be an effective strategy in regulating metabolic factors of cardiovascular diseases. Conversely, LCD may be associated with higher mortality and metabolic dysregulations if it contains large amounts of animal-based foods, particularly saturated fat.

Prevention of Diabetes and Cardiovascular Disease in Obesity

Obesity is one of the major risk factors for the development of both impaired glucose tolerance (IGT, or prediabetes) and type 2 diabetes (T2D), and its prevalence worldwide drives toward an increased rate of cardiovascular morbidity and mortality. Given the estimations of the World Health Organization (WHO) and the recommendation of the Diabetes Prevention Program (DPP), where IGT and diabetes are considered as risk factors for the development of cardiovascular complications and obesity, the development of diabetes should be treated because of its potential reversibility. In this view, several interventions such as diet, lifestyle changes, and pharmacological treatment are effective, including bariatric metabolic surgery (BMS), which is the most incisive way to efficiently lower body weight. In this review, we sought to summarize some of the major aspects linked to diabetes prevention in overweight/obesity, focusing on the use of surgery; we also attempted to elucidate molecular pathways involved in a variety of obesity-induced processes able to favor the progression of chronic diseases, such as diabetes and its complications.

Nutritional profiling of frail and obese, community dwelling older subjects: Results from a national survey

INTRODUCTION

Less attention has been given to the detection and nutritional status and needs of obese frail/sarcopenic older subjects. The aim of this study was to characterize the nutritional composition in older (≥65 years), frail-prone, obese subjects (defined by either waist circumference [WC] or body mass index [BMI]).

METHODS

A cross-sectional study with analysis of the national survey "Mabat Zahav". Random sample of 1751 community dwelling Israeli older adults (≥65 years). Eleven nutritional factors formerly linked to frailty were a-priori selected based on the current literature. Data was extracted from a 24-hour dietary recall. Adherence for each nutritional factor was defined using the Dietary Reference Intakes (DRI), and aggregated into a sum score of the overall adherence (ranging from "0" to "11", where "fair" adherence was defined as ≥6; inadequate adherence otherwise). Frailty likelihood was estimated using a validated non-direct model, and associations of nutritional factors with frailty-likelihood in obese vs non-obese individuals were examined. Additionally, a decision tree procedure based on machine learning was applied in order to capture nutritional factors related to frailty, stratified by gender, as well as by WC and/or BMI.

RESULTS

Overall, the prevalence rates of frailty and pre-frailty were 7.1 and 57.6%, respectively. A "fair nutritional adherence" was less common among frail-prone compared to robust subjects (23.1% vs. 32.1%; p < 0.0001). The intake of most frailty-related nutritional factors did not co-segregate according to the presence of abdominal or BMI-defined obesity. Still, compared to robust normal/overweight subjects, frail-prone obese (by BMI) individuals had a higher rate of inadequate nutritional adherence (odds-ratio 1.842; p < 0.05). Of all 11 nutritional factors, folate in obese women and vitamin A (as retinol) and calcium in non-obese and obese men, respectively, were recognized as the most prominent predictors of frail-prone prevalence by the machine learning process. Although BMI was more closely associated with impaired intake of the 11 selected nutritional components than WC, this association was eliminated when frailty status, low income and education were considered.

CONCLUSIONS

Frail-prone subjects differed from robust subjects in their nutritional intake. Nutritional inadequacies related to frailty-likelihood were mostly seen among obese women and non-obese men. In the prediction of inadequate adherence to the DRI of 11 nutritional components, obesity is a weaker predictor than frailty, lower education and low income in older Israeli adults.

The Effect of Aerobic and Resistance Training and Combined Exercise Modalities on Subcutaneous Abdominal Fat: A Systematic Review and Meta-analysis of Randomized Clinical Trials

Subcutaneous abdominal adipose tissue (SAT), is the largest fat depot and major provider of free fatty acids to the liver. Abdominal fat is indirectly (via increased levels of low-grade inflammation) correlated with many of the adverse health effects of obesity. Although exercise is one of the most prominent components of obesity management, its effects on SAT are still unclear. The aim of this study was to investigate the independent effects of aerobic training (AT) and resistance training (RT) modalities and combined exercise modalities on SAT in adults. PubMed, SCOPUS, and Google Scholar were searched to find relevant publications up to November 2018. The effect sizes were represented as weighted mean difference (WMD) and 95% CIs. Between-study heterogeneity was examined using the I2 test. Overall, 43 identified trials that enrolled 3552 subjects (2684 women) were included. After removal of outliers, combining effect sizes indicated a significant effect of AT (WMD: -13.05 cm2; 95% CI: -18.52, -7.57; P < 0.001), RT (WMD: -5.39 cm2; 95% CI: -9.66, -1.12; P = 0.01), and combined exercise training (CExT; WMD: -28.82 cm2; 95% CI: -30.83, -26.81; P < 0.001) on SAT relative to control groups. Pooled effect sizes demonstrated a significant effect of AT on SAT compared with a CExT group (WMD: 11.07 cm2; 95% CI: 1.81, 20.33; P = 0.01). However, when comparing the AT and RT groups, no significant difference was seen in SAT (WMD: -0.73 cm2; 95% CI: -4.50, 3.04; P = 0.70). Meta-analysis of relevant trials indicated that AT, RT, and CExT lead to SAT reduction. Aerobic exercise was shown to produce greater efficacy in decreasing SAT.

Weight loss normalizes enhanced expression of the oncogene survivin in visceral adipose tissue and blood leukocytes from individuals with obesity

BACKGROUND/OBJECTIVES

Survivin is an oncogene associated with a decrease in apoptosis, an increase in tumor growth, and poor clinical outcome of diverse malignancies. A correlation between obesity, cancer, and survivin is reported in the literature. To date, the impact of weight loss on change in survivin levels is understudied. This study was aimed at: (1) comparing survivin levels in adipose tissue (AT) from lean and obese animal models and evaluating changes after weight loss induced by energy restriction and/or exercise; (2) comparing survivin levels in normal weighted and obese humans and evaluating changes in survivin levels after weight loss induced by a very-low-calorie ketogenic diet (VLCKD) or bariatric surgery in AT and/or blood leukocytes (PBL/PBMCs).

SUBJECTS/METHODS

Survivin expression was evaluated in subcutaneous (SAT) and visceral (VAT) AT derived from animal models of monogenic (Zucker rats) and diet-induced obesity (Sprague Dawley rats and C57BL/6J mice) and after a 4-week weight-loss protocol of energy restriction and/or exercise. Plasma was used to measure the inflammatory status. Survivin expression was also evaluated in PBMCs from patients with obesity and compared with normal weight, in PBLs after VLCKD, and in SAT and/or PBLs after bariatric surgery.

RESULTS

Survivin expression was specifically higher in VAT from obese that lean animals, without differences in SAT. It decreased after weight loss induced by energy restriction and correlated with adiposity and inflammatory markers. In humans, the correlation between being obese and higher levels of survivin was confirmed. In obese subjects, survivin levels were reduced following weight loss after either VLCKD or bariatric surgery. Particularly, a decrease in PBMCs expression (not in SAT one) was found after surgery.

CONCLUSIONS

Weight loss is effective in decreasing survivin levels. Also, PBL/PBMC should be regarded as appropriate mirror of survivin levels in VAT for the identification of an obesity-related protumoral microenvironment.

Limitation of adipose tissue by the number of embryonic progenitor cells

Adipogenesis in adulthood replaces fat cells that turn over and can contribute to the development of obesity. However, the proliferative potential of adipocyte progenitors in vivo is unknown (Faust et al., 1976; Faust et al., 1977; Hirsch and Han, 1969; Johnson and Hirsch, 1972). We addressed this by injecting labeled wild-type embryonic stem cells into blastocysts derived from lipodystrophic A-ZIP transgenic mice, which have a genetic block in adipogenesis. In the resulting chimeric animals, wild-type ES cells are the only source of mature adipocytes. We found that when chimeric animals were fed a high-fat-diet, animals with low levels of chimerism showed a significantly lower adipose tissue mass than animals with high levels of chimerism. The difference in adipose tissue mass was attributed to variability in the amount of subcutaneous adipose tissue as the amount of visceral fat was independent of the level of chimerism. Our findings thus suggest that proliferative potential of adipocyte precursors is limited and can restrain the development of obesity.

The impact of weight change on intra-abdominal and hernia volumes

BACKGROUND

Weight loss is often encouraged or required before open ventral hernia repair. This study evaluates the impact of weight change on total, intra-abdominal, subcutaneous, and hernia volume.

METHODS

Patients who underwent open ventral hernia repair from 2007 to 2018 with two preoperative computed tomography scans were identified. Scans were reviewed using 3D volumetric software. Demographics, operative characteristics, and outcomes were evaluated. The impact of weight change on intra-abdominal, subcutaneous, and hernia volume was assessed using Spearman's correlation coefficients and linear regression models.

RESULTS

A total of 250 patients met the criteria with a mean defect area of 155.6 ± 155.4 cm², subcutaneous volume of 6,800.0 ± 3,868.8 cm³, hernia volume of 915.7 ± 1,234.5 cm³, intra-abdominal volume equaling 4,250.2 ± 2,118.1 cm³, and time between computed tomography scans 13.9 ± 11.0 months. Weight change was associated with change in hernia, intra-abdominal, total, and subcutaneous volume (Spearman's correlation coefficients 0.17, 0.48, 0.51, 0.45, respectively, P ≤ 0.03 all values) and not associated in hernia length, width, or area (P ≥ 0.18 all values). A Δ5 kg was significantly associated with Δintra-abdominal volume (164.1 ± 30.0 cm³/Δ5 kg,P < .0001), Δtotal volume (209.9 ± 33.0 cm³/Δ5 kg, P < .0001), and Δsubcutaneous volume (234.4 ± 50.8 cm³/Δ5 kg, P < .0001). Per Δ5 kg, male patients had more than double the Δintra-abdominal, Δtotal, and Δsubcutaneous volume than did female patients. A weight change of 5 kg to10 kg was associated with approximately double the change in computed tomography parameters/Δ5 kg than any weight change after 10 kg. Regardless of weight change, all measured hernia parameters increased over time, with mean hernia volume of +40.6 ± 94.9 cm³/mo and area of +7.8 ± 13.3 cm²/mo (Spearman's correlation coefficient -0.03 to 0.07, P value 0.37-0.96).

CONCLUSION

Weight change is linearly correlated with intra-abdominal and subcutaneous fat gain or loss. Males show greater abdominal-related response to weight gain or loss. Hernia dimensions increase over time regardless of weight change.

The Relationship of VO2 Peak and the Blood Lactate Transition Threshold with Metabolic Syndrome and Its Component Disorders

Background: Improvements in cardiorespiratory fitness attenuate the risk for metabolic syndrome (MetS). However, the determinants of cardiorespiratory fitness measurements such as oxygen consumption (VO₂) peak and anaerobic threshold (AT) have not been investigated in persons with MetS. Therefore, the main aim of this study was to compare VO₂ peak and AT between subjects with and without MetS and to investigate determinants of cardiorespiratory fitness and its effects on the odds for MetS and its individual components. Methods: Thirty-one males with MetS and 24 healthy male participants each performed a VO₂ peak and a blood lactate transition threshold test. Waist circumference, body mass index (BMI), blood pressure, fasting plasma triglyceride, total cholesterol, high-density lipoprotein cholesterol, glucose, and insulin levels were measured. Separate multivariable linear regression models were developed in which VO₂ peak, AT, and the components of MetS were used as the dependent variables, while a multivariable logistic regression model was used for MetS. Results: The VO₂ peak [median (interquartile range)] was lower in subjects with MetS compared with controls [27.9 (23.0-31.0) vs. 35.0 (32.0-45.0) mL·min^-1·kg^-1; P < 0.0001]. Multivariable regression analysis demonstrated that there was a bidirectional association between MetS and VO₂ peak that was mediated by waist circumference and blood pressure. The VO₂ peak was a strong negative determinant of waist circumference (β = -0.36, P < 0.0001), but not of BMI (β = -0.13, P = 0.21). Conclusions: A higher VO₂ peak is associated with a lower odds ratio for MetS, which is related to greater cardiorespiratory fitness in a cyclical relationship that is mediated by blood pressure and waist circumference. A higher VO₂ peak is specifically associated with lower waist circumference, and vice versa, possibly by effects on visceral fat.