Endoscopic visceral fat removal as therapy for obesity and metabolic syndrome: a sham-controlled pilot study (with video)

Selective reduction of visceral adipose tissue with injectable ice slurry

Reduction in visceral adipose tissue (VAT) mass reduces body weight and metabolic disease risk in obese patients. However surgical removal of VAT is highly invasive and thus not clinically feasible. We developed an injectable ice slurry for selective reduction of adipose tissue through cryolipolysis. The aim of this study was to investigate safety, feasibility and mechanism of ice slurry-induced cryolipolysis of VAT. Perigonadal VAT in diet-induced obese mice and rats was subjected to slurry or sham treatment. Body weight and blood chemistry were monitored for 56 days post-treatment. Histological analysis and molecular studies were performed to elucidate mechanisms of fat reduction. Treatment of VAT was well tolerated in all animals. Slurry induced adipocyte cell death via selective cryolipolysis; significant weight loss was noted at day 21 post-treatment. RNA sequencing from treated VAT samples showed increased expression of genes involved in inflammation, immune response, collagen biosynthesis and wound healing, and decreased expression of adipokines. This study demonstrates that slurry treatment is safe and effective in inducing cryolipolysis of VAT and subsequent weight loss in mice. Ice slurry is promising as a minimally-invasive treatment to reduce visceral adipose tissue.

Sex-Specific Changes in Body Composition Following Metabolic and Bariatric Surgery Are Associated with the Remission of Metabolic Syndrome

PURPOSE

Metabolic and bariatric surgery (MBS) is the most effective treatment for metabolic syndrome (MetS). However, the mechanism of MetS remission after MBS remains unclear. We aimed to explore the relationship between sex differences, body composition, and the remission of MetS after MBS.

MATERIALS AND METHODS

Cross-sectional study of 80 patients with obesity and MetS who underwent MBS with case-control design. The International Diabetes Federation criteria were used to define MetS. Body composition was measured using dual-energy X-ray absorptiometry before and 1 year after the operation. In addition to calculating changes in MetS and its prevalence, we performed a multiple logistic regression to determine predictors of MetS remission.

RESULTS

There were significant differences in body composition between males and females after MBS. Both males and females had significant improvements in the overall prevalence of MetS, decreasing from 100 to 21.74% (P <0.001) and from 100 to 35.29% (P <0.001), respectively. A higher percentage of visceral adipose tissue (VAT) reduction tends to be associated with a higher chance of MetS remission in men. In females, the MetS nonremission subgroup had a higher %Trunk lean body mass (LBM), and %Android LBM reduction than the remission subgroup, but the multiple logistic regression analysis result was not statistically significant.

CONCLUSION

After MBS, reduced VAT might be related to MetS reversibility in males, while reduced LBM may result in MetS nonremission in females.

Preliminary adipose removal did not prevent diet-induced metabolic disorders in mice

Background:

Obesity is a fundamental factor in metabolic disorders such as hyperlipidemia, insulin resistance, fatty liver, and atherosclerosis. However, effective preventive measures are still lacking. This study aimed to investigate different surgical protocols for removing partial adipose tissue before the onset of obesity and determine whether, and by which protocol, preliminary adipose removal could exert potent preventive effects against diet-induced metabolic disorders.

Methods:

Male low-density lipoprotein receptor (LDL-R) knockout (KO) mice were randomly divided into four groups and subjected to epididymal fat removal (Epi-FR) surgery, subcutaneous fat removal (suQ-FR) surgery, both subcutaneous and epididymal fat removal (Epi + suQ-FR) surgery, or sham-operation. After 1 week of recovery, all mice were given a high-fat diet (HFD) for 10 weeks to induce metabolic disorders.

Results:

In the Epi-FR group and the sham-operated group, the mean numbers of the residual subcutaneous fat were 28.59 mg/g and 18.56 mg/g, respectively. The expression of relative genes such as Pparg, Cebpa, Dgat2, Fabp4 and Cd36 in the residual subcutaneous fat increased 2.62, 3.90, 3.11, 2.06, 1.78 times in the Epi-FR group compared with that in the sham-operated group. Whereas in the other fat-removal groups, the residual fat depots had no significant change in either size or gene expression, as compared with those of the sham-operated group. Plasma lipid and glucose levels and insulin sensitivity, as detected by the glucose tolerance test, were not significantly alleviated in the three fat removal groups. Liver mass or lipid content was not attenuated in any of the three fat removal groups. The atherosclerosis burdens in the entire inner aorta and aortic root did not decrease in any of the three fat removal groups.

Conclusions:

Our data suggest that removal of epididymal adipose or subcutaneous adipose alone or in combination before the onset of obesity did not protect against hyperlipidemia, insulin resistance, fatty liver, or atherosclerosis in LDL-R KO mice fed with a HFD. Hence, adipose removal possibly does not represent a potential approach in preventing obesity-related metabolic disorders in the obesity-susceptible population.

Omental Adipose Removal Decreases High Blood Pressure in Hypertensive Patients Independent of Body Mass Index

AIM

Several studies have demonstrated that increased omental adipose is a risk factor for obesity and metabolic syndrome. It remains unclear whether it is responsible for hypertension as an independent risk. This study was designed to assess the impact of omental adipose removal by surgery on blood pressure in cancer patients with or without hypertension.

METHODS AND RESULTS

In this prospective observational study, 133 patients with gastric or gynecological cancer were divided into 3 groups: non-hypertensive and omentum removed (NH&OR), hypertensive and omentum removed (H&OR), and hypertensive and omentum present (H&OP). Patients were followed up with systolic and diastolic blood pressure (SBP and DBP), changes in related body mass index and metabolic indices. The time points of the 2 follow-up visits were 1 month ± 7 days after the operation before the start of chemotherapy and the endpoint of 8 ± 1 month. Omental adipose tissues from both non-hypertensive and hypertensive patients in surgery were collected. We included 133 patients (84.2% female, 20.3% malignant gastric cancer and 79.7% malignant gynecological cancer, 78.2% omentum removal, 48.9% hypertensive), and all completed follow-up. H&OR group showed significant reductions in systolic and diastolic blood pressure compared with the baseline at 1-m (-16.94/-10.50 mmHg, both P < 0.001) and 8-m end point (-16.00/-5.50 mmHg, P < 0.001 and P = 0.004). Little reductions were observed with the body mass index of patients in 3 groups till the endpoint of study (H&OR group: 24.60 kg/m² to 23.57 kg/m², NH&OR group: 23.45 kg/m² to 23.25 kg/m², H&OP group: 25.74 kg/m² to 25.24 kg/m², all P > 0.05). No correlation was found between the baseline body mass index and 8-m change of systolic and diastolic blood pressure in omentum removed groups. In both groups, triglyceride levels were significantly increased at 4 ± 1 week after surgery (NH&OR 0.32 mmol/L, P = 0.006; H&OR 0.40 mmol/L, P = 0.010).

CONCLUSION

Resection of omental adipose tissue represents an effective strategy for reducing systolic and diastolic blood pressure at 8 months in hypertensive patients, even in the non-obese hypertensive population.

Omentectomy Prevents Metabolic Syndrome By Reducing Appetite and Body Weight In A Diet-Induced Obesity Rat Model

Visceral fat deposition is associated with impairment of glucose and lipid metabolism while leptin levels are frequently related to subcutaneous fat area. At present, there is considerable controversy regarding the role of visceral adipose tissue accumulation in the development of metabolic syndrome (MS). Here we show the effects of omentectomy on the liver and MS in a diet induced obesity rat model. Our results reveal that undergoing omentectomy previously the establishment of the diet-induced-obesity reduced significantly body weight gain and avoid the development of MS, including non-alcoholic fatty liver disease. Intriguingly, the significantly lower body weight gain was due to decreased food intake. Omentum drives obesity progression through leptin resistance mediated by C-reactive protein, Interleucin (IL)-6 and high lipolysis activity. Omentum removal reversed immediately the increased plasma levels of CRP and IL-6 and gradually food intake, weight gain, and features of MS in diet-induced-obesity. Omentectomy caused no changes in normal-weigh-rats. This report displays causal mechanism by which omentum promotes obesity and propose omentectomy as a promising procedure in MS prevention.

Imbalanced insulin action in chronic over nutrition: Clinical harm, molecular mechanisms, and a way forward

The growing worldwide prevalence of overnutrition and underexertion threatens the gains that we have made against atherosclerotic cardiovascular disease and other maladies. Chronic overnutrition causes the atherometabolic syndrome, which is a cluster of seemingly unrelated health problems characterized by increased abdominal girth and body-mass index, high fasting and postprandial concentrations of cholesterol- and triglyceride-rich apoB-lipoproteins (C-TRLs), low plasma HDL levels, impaired regulation of plasma glucose concentrations, hypertension, and a significant risk of developing overt type 2 diabetes mellitus (T2DM). In addition, individuals with this syndrome exhibit fatty liver, hypercoagulability, sympathetic overactivity, a gradually rising set-point for body adiposity, a substantially increased risk of atherosclerotic cardiovascular morbidity and mortality, and--crucially--hyperinsulinemia. Many lines of evidence indicate that each component of the atherometabolic syndrome arises, or is worsened by, pathway-selective insulin resistance and responsiveness (SEIRR). Individuals with SEIRR require compensatory hyperinsulinemia to control plasma glucose levels. The result is overdrive of those pathways that remain insulin-responsive, particularly ERK activation and hepatic de-novo lipogenesis (DNL), while carbohydrate regulation deteriorates. The effects are easily summarized: if hyperinsulinemia does something bad in a tissue or organ, that effect remains responsive in the atherometabolic syndrome and T2DM; and if hyperinsulinemia might do something good, that effect becomes resistant. It is a deadly imbalance in insulin action. From the standpoint of human health, it is the worst possible combination of effects. In this review, we discuss the origins of the atherometabolic syndrome in our historically unprecedented environment that only recently has become full of poorly satiating calories and incessant enticements to sit. Data are examined that indicate the magnitude of daily caloric imbalance that causes obesity. We also cover key aspects of healthy, balanced insulin action in liver, endothelium, brain, and elsewhere. Recent insights into the molecular basis and pathophysiologic harm from SEIRR in these organs are discussed. Importantly, a newly discovered oxide transport chain functions as the master regulator of the balance amongst different limbs of the insulin signaling cascade. This oxide transport chain--abbreviated 'NSAPP' after its five major proteins--fails to function properly during chronic overnutrition, resulting in this harmful pattern of SEIRR. We also review the origins of widespread, chronic overnutrition. Despite its apparent complexity, one factor stands out. A sophisticated junk food industry, aided by subsidies from willing governments, has devoted years of careful effort to promote overeating through the creation of a new class of food and drink that is low- or no-cost to the consumer, convenient, savory, calorically dense, yet weakly satiating. It is past time for the rest of us to overcome these foes of good health and solve this man-made epidemic.

Effects of omentectomy in addition to sleeve gastrectomy on the metabolic and inflammatory profiles of obese rats

BACKGROUND

Visceral obesity has been considered a risk factor for metabolic and cardiovascular complications. In an attempt to reduce the visceral adipose tissue, omentectomy has been proposed to be performed along with bariatric surgery.

OBJECTIVE

The goal of this study was to evaluate whether omentectomy associated with sleeve gastrectomy (SG) is beneficial to the inflammatory and metabolic profile of rats fed a standard diet (STD) or high-fat diet (HFD).

SETTING

University hospital, Brazil.

METHODS

For this experiment, male Wistar rats were randomly divided into 6 groups as follows: sham surgery (STD+L or HFD+L), SG alone (STD+SG or HFD+SG), or SG with omentectomy (STD+SGO or HFD+SGO). Anthropometric data and metabolic profiles were evaluated, and the tissue expression of inflammatory markers in the visceral adipose tissue was measured.

RESULTS

In rats with diet-induced obesity treated with SG with or without omentectomy, there was a reduction in weight (HFD+SG: P<.01 and HFD+SGO: P<.05), adiposity (HFD+SG: P<.001 and HFD+SGO: P<.05), plasma levels of glucose (HFD+SG: P<.01 and HFD+SGO: P<.01), plasma levels of C-peptide (HFD+SG: P<.01 and HFD+SGO: P<.001), plasma levels of insulin (HFD+SG: P<.05 and HFD+SGO: P<.001), plasma levels of total cholesterol (HFD+SG: P<.01 and HFD+SGO: P<.01), and tissue expression of TNF-α (HFD+SG: P<.001 and HFD+SGO: P<.01), but there was no statistically significant difference between the groups in which omentectomy was performed or was not.

CONCLUSION

In this study, we did not observe additional beneficial effects due to omentectomy associated with SG in the metabolic profile and tissue expression of inflammatory markers.

Adipose tissues as endocrine target organs

In the context of obesity, white adipocyte hypertrophy and adipose tissue macrophage infiltration result in the production of pro-inflammatory adipocytokines inducing insulin resistance locally but also in distant organs and contributing to low grade inflammatory status associated with the metabolic syndrome. Visceral adipose tissue is believed to play a prominent role. Brown and beige adipose tissues are capable of energy dissipation, but also of cytokine production and their role in dysmetabolic syndrome is emerging. This review focuses on metabolic and inflammatory changes in these adipose depots and contribution to metabolic syndrome. Also we will review surgical and pharmacological procedures to target adiposity as therapeutic interventions to treat obesity-associated disorders.