Obesity and the Metabolic Syndrome

Activation of CXCR7 exerts an inhibitory effect on adipogenesis through regulation of β-arrestin2/Wnt and AKT signalling

CXCR7, an alternative receptor for the inflammatory chemokine SDF-1, is involved in cell proliferation and migration. Recent studies have reported that CXCR7 also plays a role in adipose tissue. However, evidence regarding the role of CXCR7 and its ligands in adipocyte differentiation is limited. In this study, we aimed to elucidate changes in CXCR7 expression during adipocyte differentiation and the role of the SDF-1/CXCR7/CXCR4 axis in adipogenesis using recombinant SDF-1, the CXCR7 ligand CCX771, and small interfering RNAs. The results indicated that the levels of SDF-1 and its receptors, CXCR7 and CXCR4, decreased during the early stages of adipogenesis. Treatment with recombinant SDF-1 and CCX771 inhibited adipogenesis and lipid accumulation by inducing β-arrestin2, Wnt expression, and AKT phosphorylation and downregulating C/EBPα, PPARγ, and FABP4 expression. In contrast, knockdown of SDF-1 and CXCR7 in preadipocytes downregulated the β-arrestin2/Wnt and AKT pathway, leading to the induction of adipogenesis. Meanwhile, knockdown of CXCR4 had no significant effect. In mice, basal gene expression levels of SDF-1 and CXCR7 were higher in the stromal vascular fraction compared to mature adipocytes and were significantly upregulated by a high-fat diet. Our results provide new insights into the local role of the SDF-1-CXCR7 axis in adipocytes and offer additional benefits for the prevention of obesity-related metabolic disorders.

Efficacy of orlistat in obese patients with nonalcoholic fatty liver disease: a systematic review and meta-analysis of randomized controlled trials

Objective: Nonalcoholic fatty liver disease (NAFLD) or metabolic dysfunction-associated steatotic liver disease (MASLD) is a significant contributor to chronic liver disease worldwide. Orlistat blocks intestinal fat absorption, leading to decreased liver fat content. Therefore, it is a viable option for NAFLD management. Methods: We performed a systematic review and metaanalysis using randomized controlled trials (RCTs). We used mean difference (MD) to pool continuous outcomes presented with the corresponding confidence interval (CI). Results: We included four RCTs with a total of 379 patients. Orlistat was effective in reducing liver fat content (MD: -5.02, 95% CI [-7.23, -2.82], P = 0.00001), alanine transferase (MD: -10.03, 95% CI [-17.80, -2.26], P = 0.01), aspartate transferase (MD: -4.29, 95% CI [-7.59, -0.99], P = 0.01), waist circumference (MD: -3.18, 95% CI [-4.25, -2.10], P = 0.00001), body mass index (MD: -1.03, 95% CI [-1.34, -0.73], P = 0.00001), total cholesterol (MD: -3.75, 95% CI [-4.02, -3.49], P = 0.00001), and low-density lipoprotein (MD: -3.83, 95% CI [-4.05, -3.61], P = 0.00001). However, orlistat was associated with increased serum triglycerides (MD: 7.46, 95% CI [6.48, 8.44], P = 0. 00001). Conclusion: Orlistat is a viable option for NAFLD management; however, it increases triglyceride levels. Larger RCTs are required.

Prevalence of metabolically healthy obesity and healthy overweight and the associated factors in southern Iran: A population-based cross-sectional study

Background and Aims

Obesity is considered a major growing threat to public health which could negatively affect the quality of life. The current cross-sectional study was conducted to investigate the population-based prevalence of metabolically healthy obesity (MHO) and healthy overweight (MHOW) and associated factors in southern Iran.

Methods

Baseline data from the Pars Cohort Study was analyzed. Metabolically healthy participants were identified based on the definition of the American Heart Association for the metabolic syndrome. The prevalence of MHOW and MHO and their 95% confidence intervals were estimated. Poisson regression was applied for the calculation of prevalence ratios (PRs).

Results

Gender- and age-standardized prevalences of MHOW and MHO were 6.3% (6.0%-6.6%) and 2.3% (2.1%-2.5%), respectively. The following factors were associated with being MHOW compared with those with normal weight: Being younger, female gender (1.31, 1.20-1.43), higher socioeconomic status, being noncurrent cigarette smoker (1.27, 1.11-1.45), low level of physical activity (1.14, 1.03-1.25), having normal overweight during adolescence, and overweight (1.35, 1.24-1.48) or obesity (1.68, 1.53-1.86) during young adulthood. We also found strong associations between MHO and younger age groups, female gender (2.87, 2.40-3.42), being married (1.57, 1.08-2.27), Fars ethnicity (1.25, 1.10-1.43), higher socioeconomic status, ever use of tobacco (1.14, 1.00-1.30), never use of opium (1.85, 1.19-2.86), lower physical activity (1.45, 1.20-1.72), being normal weight in 15-year body pictogram and being overweight (1.87, 1.59-2.20) or obese (3.20, 2.74-3.72) in 30-year body pictogram when considering those with normal weight or MHO.

Conclusion

Potentially modifiable factors including physical activity should be more emphasized. Furthermore, our study issued that it would be more reasonable that the prevention of unhealthy obesity be initiated before the development of MHO, where there are more protective factors and they could be more effective.

Nuciferine Protects against Obesity-Induced Nephrotoxicity through Its Hypolipidemic, Anti-Inflammatory, and Antioxidant Effects

High-fat diets (HFD) could cause obesity, trigger lipid accumulation, and induce oxidative stress and inflammation, leading to kidney damage. This study aimed to elucidate the protective effects of nuciferine on HFD-caused nephrotoxicity and explore the underlying mechanisms in Kunming mice and palmitic acid-exposed HK-2 cells. In obese mice, nuciferine notably alleviated HFD-induced chronic renal dysfunction and delayed renal fibrosis progression and podocyte apoptosis, as evidenced by the increased expressions of renal function factors BUN, CRE, and UA and the decreased expressions of key protein factors TGF-β1, p-Samd3, Wnt-1, and β-catenin. Nuciferine also effectively attenuated HFD-induced renal lipid accumulation via the AMPK-mediated regulation of FAS and HSL expressions and suppressed inflammation and oxidative stress via the AMPK-mediated Nrf-2/HO-1 and TLR4/MyD88/NF-κB pathways. In addition, consistent with the results of animal experiments, nuciferine remarkably reversed cell damage and attenuated lipid accumulation, inflammation, and oxidative stress in palmitic acid-exposed HK-2 cells through the AMPK-mediated signaling pathway. Therefore, nuciferine could be a new food-derived protective agent to offset obesity and correlative kidney damage.

Relationships between body fat distribution and metabolic syndrome traits and outcomes: A mendelian randomization study

BACKGROUND

Obesity is a complex, multifactorial disease associated with substantial morbidity and mortality worldwide. Although it is frequently assessed using BMI, many epidemiological studies have shown links between body fat distribution and obesity-related outcomes. This study examined the relationships between body fat distribution and metabolic syndrome traits using Mendelian Randomization (MR).

METHODS/FINDINGS

Genetic variants associated with visceral adipose tissue (VAT), abdominal subcutaneous adipose tissue (ASAT), and gluteofemoral adipose tissue (GFAT), as well as their relative ratios, were identified from a genome wide association study (GWAS) performed with the United Kingdom BioBank. GWAS summary statistics for traits and outcomes related to metabolic syndrome were obtained from the IEU Open GWAS Project. Two-sample MR and BMI-controlled multivariable MR (MVMR) were performed to examine relationships between each body fat measure and ratio with the outcomes. Increases in absolute GFAT were associated with a protective cardiometabolic profile, including lower low density lipoprotein cholesterol (β: -0.19, [95% CI: -0.28, -0.10], p < 0.001), higher high density lipoprotein cholesterol (β: 0.23, [95% CI: 0.03, 0.43], p = 0.025), lower triglycerides (β: -0.28, [95% CI: -0.45, -0.10], p = 0.0021), and decreased systolic (β: -1.65, [95% CI: -2.69, -0.61], p = 0.0019) and diastolic blood pressures (β: -0.95, [95% CI: -1.65, -0.25], p = 0.0075). These relationships were largely maintained in BMI-controlled MVMR analyses. Decreases in relative GFAT were linked with a worse cardiometabolic profile, with higher levels of detrimental lipids and increases in systolic and diastolic blood pressures.

CONCLUSION

A MR analysis of ASAT, GFAT, and VAT depots and their relative ratios with metabolic syndrome related traits and outcomes revealed that increased absolute and relative GFAT were associated with a favorable cardiometabolic profile independently of BMI. These associations highlight the importance of body fat distribution in obesity and more precise means to categorize obesity beyond BMI.

The impact of a maternal and offspring obesogenic diet on daughter's oocyte mitochondrial ultrastructure and bioenergetic responses. Insights from an outbred mouse model

Obesity affects oocyte mitochondrial functions and reduces oocyte quality and fertility. Obesity may also increase the risk of metabolic disorders in the offspring. Children are likely to follow their parents lifestyle and diet, which also contributes to the increased prevelance of obesity across generations. We hypothesise that the impact of obesogenic (OB) diet and obesity on oocyte mitochondrial functions is different in offspring born to obese mothers compared to those born to healthy mothers. To test this hypothesis, we fed a control (C, 10% fat, 7% sugar) or an OB diet (60% fat, 20% sugar) to female mice (for 7 weeks (w)) and then to their female offspring (for 7w after weaning) in a 2 × 2 factorial design (C » C, n = 35, C » OB, n = 35, OB » C n = 49 and OB » OB, n = 50). Unlike many other studies, we used an outbred Swiss mouse model to increase the human pathophysiological relevance. Offspring were sacrificed at 10w and their oocytes were collected. Offspring OB diet increased oocyte lipid droplet content, mitochondrial activity and reactive oxygen species (ROS) levels, altered mitochondrial ultrastructure and reduced oocyte pyruvate consumption. Mitochondrial DNA copy numbers and lactate production remained unaffected. Mitochondrial ultrastructure was the only factor where a significant interaction between maternal and offspring diet effect was detected. The maternal OB background resulted in a small but significant increase in offspring's oocyte mitochondrial ultrastructural abnormalities without altering mitochondrial inner membrane potential, active mitochondrial distribution, mitochondrial DNA copy numbers, or ROS production. This was associated with reduced mitochondrial complex III and V expression and reduced pyruvate consumption which may be compensatory mechanisms to control mitochondrial inner membrane potential and ROS levels. Therefore, in this Swiss outbred model, while offspring OB diet had the largest functional impact on oocyte mitochondrial features, the mitochondrial changes due to the maternal background appear to be adaptive and compensatory rather than dysfunctional.

The effect of smoking on latent hazard classes of metabolic syndrome using latent class causal analysis method in the Iranian population

BACKGROUND

The prevalence of metabolic syndrome is increasing worldwide. Clinical guidelines consider metabolic syndrome as an all or none medical condition. One proposed method for classifying metabolic syndrome is latent class analysis (LCA). One approach to causal inference in LCA is using propensity score (PS) methods. The aim of this study was to investigate the causal effect of smoking on latent hazard classes of metabolic syndrome using the method of latent class causal analysis.

METHODS

In this study, we used data from the Tehran Lipid and Glucose Cohort Study (TLGS). 4857 participants aged over 20 years with complete information on exposure (smoking) and confounders in the third phase (2005-2008) were included. Metabolic syndrome was evaluated as outcome and latent variable in LCA in the data of the fifth phase (2014-2015). The step-by-step procedure for conducting causal inference in LCA included: (1) PS estimation and evaluation of overlap, (2) calculation of inverse probability-of-treatment weighting (IPTW), (3) PS matching, (4) evaluating balance of confounding variables between exposure groups, and (5) conducting LCA using the weighted or matched data set.

RESULTS

Based on the results of IPTW which compared the low, medium and high risk classes of metabolic syndrome (compared to a class without metabolic syndrome), no association was found between smoking and the metabolic syndrome latent classes. PS matching which compared low and moderate risk classes compared to class without metabolic syndrome, showed that smoking increases the probability of being in the low-risk class of metabolic syndrome (OR: 2.19; 95% CI: 1.32, 3.63). In the unadjusted analysis, smoking increased the chances of being in the low-risk (OR: 1.45; 95% CI: 1.01, 2.08) and moderate-risk (OR: 1.68; 95% CI: 1.18, 2.40) classes of metabolic syndrome compared to the class without metabolic syndrome.

CONCLUSIONS

Based on the results, the causal effect of smoking on latent hazard classes of metabolic syndrome can be different based on the type of PS method. In adjusted analysis, no relationship was observed between smoking and moderate-risk and high-risk classes of metabolic syndrome.

Prevalence of metabolic syndrome and components in rural, semi-urban and urban areas in the littoral region in Cameroon: impact of physical activity

BACKGROUND

Living areas in developing countries impact seriously lifestyle by modifying energy consumption and energy expenditure. Thus, urbanization is associated with less practice of physical activity (PA), a leading cause of metabolic syndrome (MetS) which prevalence vary in African countries. The present study aimed to assess the effect of PA on MetS according to urbanization level in the littoral region, Cameroon.

METHODS

A cross-sectional study was conducted in three geographical settings (urban, semi-urban, and rural) in the littoral region in Cameroon. A total of 879 participants were included (urban: 372, semi-urban: 195 and rural: 312). MetS was defined according to the International Federation of Diabetes 2009. The level of PA was assessed using the Global Physical Activity questionnaire.

RESULTS

Low level of PA was (P < 0.0001) reported in urban (54.5%), semi-urban (28.7%) and rural (16.9%) and high level in rural area (77.9%). The prevalence of MetS was higher in urban areas (37.2%), then rural (36.8%) and finally semi-urban (25.9%). Hyperglycemia (p = 0.0110), low HDL-c (p < 0.0001) and high triglyceridemia (p = 0.0068) were most prevalent in urban residents. Participants with low level of PA were at risk of MetS (OR: 1.751, 95% CI 1.335-2.731, p = 0.001), hyperglycemia (OR: 1.909, 95% CI 1.335-2.731, p = 0.0004) abdominal obesity(OR: 2.007, 95% CI 1.389-2.900, p = 0.0002), low HDL-c (OR: 1.539, 95% CI 1.088-2.179, p = 0.014) and those with moderate level of PA were protected against high blood pressure(OR: 0.452, 95% CI 0.298-0.686, p = 0.0002) and compared to those with high level of PA. Urban dwellers were at the risk of MetS compared to rural residents (OR: 1.708, 95% CI. 1.277-2.285, p = 0.003) and protected against high blood pressure (OR:0.314, 95% CI 0.212-0.466, p < 0.0001), abdominal obesity (OR: 0.570, 95% CI 0.409-0.794, p = 0.0009), and low HDL-c (OR: 0.725, 95% CI 0.534-0.983, p = 0.038) compared to rural residents.

CONCLUSIONS

MetS was more prevalent in urban dwellers and was associated with a low level of PA.

Sex Difference in the Associations among Obesity-Related Indices with Hyperuricemia in a Large Taiwanese Population Study

Hyperuricemia has been linked with the development of diabetes, gout, kidney, and cardiovascular diseases. Although obesity is associated with hyperuricemia, data on sex differences in this association are scarce. Therefore, this study was conducted to explore sex differences in the correlations among various indices of obesity with hyperuricemia in Taiwan. Data were obtained from the Taiwan Biobank and included 122,067 participants. After excluding 179 participants with missing data, the remaining 121,888 participants (men: 43,790; women: 78,098) were enrolled. The prevalence rates of hyperuricemia (defined as serum uric acid >7.0/6.0 mg/dL in men/women) were 29.8% and 13.6%, respectively (p < 0.001). Multivariable analysis revealed high values of body shape index (ABSI), waist-to-height ratio (WHtR), waist-hip ratio (WHR), lipid accumulation product (LAP), conicity index (CI), visceral adiposity index (VAI), body adiposity index (BAI), abdominal volume index (AVI), body mass index (BMI), and body roundness index (BRI) were significantly associated with hyperuricemia in both the male and female participants (all p < 0.001). The interactions between sex and all 10 of these indices were significant (all p < 0.001) for hyperuricemia. In men, LAP had the highest area under the curve (0.669), followed by BMI (0.655), VAI (0.645), AVI (0.642), BRI (0.640), WHtR (0.633), BAI (0.605), WHR (0.599), CI (0.574), and ABSI (0.510). In women, LAP also had the highest area under the curve (0.754), followed by BMI (0.728), VAI (0.724), WHtR (0.721), BRI (0.720), AVI (0.713), WHR (0.676), BAI (0.673), CI (0.626), and ABSI (0.544). In conclusion, obesity-related indices were associated with hyperuricemia in this large Taiwanese study, and sex differences were found in these associations, with stronger associations in women than in men.

Anti-obesity effects of Lactiplantibacillus plantarum SKO-001 in high-fat diet-induced obese mice

PURPOSE

Previous reports showed that some probiotics provide beneficial effects on various diseases including metabolic disorders. This study aimed to investigate the anti-obesity effects of Lactiplantibacillus (L.) plantarum SKO-001 (SKO-001), a probiotic strain newly isolated from Angelica gigas.

METHODS

C57BL/6J mice were fed with high-fat diet (HFD, 60% fat) for four weeks, and then different doses of SKO-001 (n = 10 each group) were orally given for 12 weeks. Following treatment, body weight, fat weight, serum parameters and adipose and liver tissues were analyzed.

RESULTS

SKO-001 (2 × 10¹⁰ CFU/day, per os) reduced body weight gain after 10th week of administration, accompanied by a reduction in body fat mass of mice. In the SKO-001-fed group, increased serum adiponectin, decreased leptin, insulin, total cholesterol, low-density lipoprotein cholesterol, free fatty acids, and triglyceride levels were observed. Hematoxylin and eosin staining of various fat depots showed that increased adipocyte size caused by HFD intake was markedly reduced and correlated with reduced mRNA levels of lipogenesis genes, including sterol regulatory element-binding protein-1c, peroxisome proliferator-activated receptor gamma, and CCAAT/enhancer binding protein alpha, and increased uncoupling protein 1 levels. Similarly, SKO-001 reduced lipid accumulation, decreased the mRNA levels of lipogenic genes, and reduced α-smooth muscle actin and collagen type 1 alpha 1 levels in the liver.

CONCLUSIONS

SKO-001 ameliorates obesity and related metabolic abnormalities in adipose and liver tissues, possibly via the regulation of lipid metabolism. Based on the results of the present study, SKO-001 may be applicable as an anti-obesity therapeutic or functional food.

Adapalene induces adipose browning through the RARβ-p38 MAPK-ATF2 pathway

Adipose browning has recently been reported to be a novel therapeutic strategy for obesity. Because the retinoic acid receptor (RAR) is a potential target involved in browning, adapalene (AD), an anti-acne agent with RAR agonism, was examined in detail for its effects on adipose browning and the underlying mechanisms in vitro and in vivo. AD upregulated the expression of adipose browning-related markers in a concentration-dependent manner, promoted mitochondrial biogenesis, increased oxygen consumption rates, and lowered lipid droplet sizes in differentiated 3T3/L1 white adipocytes. Among the three retinoic acid receptors (RARα, RARβ, and RARγ), knockdown of the gene encoding RARβ mitigated AD-induced adipose browning. Similarly, LE135 (a selective RARβ antagonist) attenuated AD action, suggesting that AD promotes adipose browning through RARβ. Sequential phosphorylation of p38 mitogen-activated protein kinase (MAPK) and activating transcription factor 2 (ATF2) was critical for AD-induced adipose browning, based on the observations that either SB203580 (a p38 MAPK inhibitor) or ATF2 siRNA reduced the effects of AD. In vivo browning effects of AD were confirmed in C57BL/6J mice and high-fat diet-induced obese (DIO) mice after oral administration of AD either acutely or chronically. This study identifies new actions of AD as an adipose browning agent and demonstrates that RARβ activation followed by increased phosphorylation of p38 MAPK and ATF2 appears to be a key mechanism of AD action.

Amelioration of Obesity in Mice Fed a High-Fat Diet with Uronic Acid–Rich Polysaccharides Derived from Tremella fuciformis

Obesity is rapidly becoming an emerging disease in developing countries due to the Westernization of societies and lifestyle changes. This study evaluated the ameliorative effect of acidic heteropolysaccharides derived from Tremella fuciformis (TFPS) on high-fat diet (HFD; 34.9% fat)-induced obesity in mice. The TFPS exhibited high uronic acid content and high viscosity in water. The structural characteristics of TFPS showed that average molecular weight was 679 kDa, and the monosaccharide composition was galactose, glucose, fructose, xylose, fucose, and mannose at a ratio of 1.0:6.5:10.0:18.5:30.5:67.5. In an in vivo study, HFD-induced obese C57BL/6 mice were orally given a TFPS treatment at 1 and 2 g/kg of body weight for 8 weeks. The TFPS treatment significantly reduced features of obesity in the mice, namely weight gain, feed efficiency, body fat percentage, and serum cholesterol level and increased fecal lipid content, compared with mice fed an HFD with water. In addition, TFPS exhibited the inhibition of cholesterol micelles in vitro in a concentration-dependent manner. In conclusion, the TFPS treatment ameliorated the diet-induced obesity in the mice, presumably reducing fat absorption in the intestine by interfering with viscous TFPS.

Updated Understanding of the Causes of Cancer, and a New Theoretical Perspective of Combinational Cancer Therapies, a Hypothesis

We present an integrative understanding of cancer as a metabolic multifactorial, multistage disease. We focus on underlying genetics-environmental interactions, evidenced by telomere changes. A range of genetic and epigenetic factors, including physical agents and predisposing factors such as diet and lifestyle are included. We present a structured model of the causes of cancer, methods of investigations, approaches to cancer prevention, and polypharmaceutical multidisciplinary complex treatment within a framework of personalized medicine. We searched PubMed, National Cancer Institute online, and other databases for publications regarding causes of cancer, reports of novel mitochondrial reprogramming, epigenetic, and telomerase therapies and state-of-the-art investigations. We focused on multistep treatment protocols to enhance early detection of cancer, and elimination or neutralization of the causes and factors associated with cancer formation and progression.Our aim is to suggest a model therapeutic protocol that incorporates the patient's genome, metabolism, and immune system status; stage of tumor development; and comorbidity(ies), if any. Investigation and treatment of cancer is a challenge that requires further holistic studies that improve the quality of life and survival rates, but are most likely to aid prevention.

Effect of Propionic Acid on Diabetes-Induced Impairment of Unfolded Protein Response Signaling and Astrocyte/Microglia Crosstalk in Rat Ventromedial Nucleus of the Hypothalamus

Background

The aim was to investigate the influence of propionic acid (PA) on the endoplasmic reticulum (ER), unfolded protein response (UPR) state, and astrocyte/microglia markers in rat ventromedial hypothalamus (VMH) after type 2 diabetes mellitus (T2DM).

Methods

Male Wistar rats were divided: (1) control, (2) T2DM, and groups that received the following (14 days, orally): (3) metformin (60 mg/kg), (4) PA (60 mg/kg), and (5) PA+metformin. Western blotting, RT-PCR, transmission electron microscopy, and immunohistochemical staining were performed.

Results

We found T2DM-associated enlargement of ER cisterns, while drug administration slightly improved VMH ultrastructural signs of damage. GRP78 level was 2.1-fold lower in T2DM vs. control. Metformin restored GRP78 to control, while PA increased it by 2.56-fold and metformin+PA—by 3.28-fold vs. T2DM. PERK was elevated by 3.61-fold in T2DM, after metformin—by 4.98-fold, PA—5.64-fold, and metformin+PA—3.01-fold vs. control. A 2.45-fold increase in ATF6 was observed in T2DM. Metformin decreased ATF6 content vs. T2DM. Interestingly, PA exerted a more pronounced lowering effect on ATF6, while combined treatment restored ATF6 to control. IRE1 increased in T2DM (2.4-fold), metformin (1.99-fold), and PA (1.45-fold) groups vs. control, while metformin+PA fully normalized its content. The Iba1 level was upregulated in T2DM (5.44-fold) and metformin groups (6.88-fold). Despite PA treatment leading to a further 8.9-fold Iba1 elevation, PA+metformin caused the Iba1 decline vs. metformin and PA treatment. GFAP level did not change in T2DM but rose in metformin and PA groups vs. control. PA+metformin administration diminished GFAP vs. PA. T2DM-induced changes were associated with dramatically decreased ZO-1 levels, while PA treatment increased it almost to control values.

Conclusions

T2DM-induced UPR imbalance, activation of microglia, and impairments in cell integrity may trigger VMH dysfunction. Drug administration slightly improved ultrastructural changes in VMH, normalized UPR, and caused an astrocyte activation. PA and metformin exerted beneficial effects for counteracting diabetes-induced ER stress in VMH.

Evidence that C/EBP-β LAP Increases Fat Metabolism and Protects Against Diet-Induced Obesity in Response to mTOR Inhibition

Aging and obesity are common risk factors for numerous chronic pathologies, and the compounding effects of old age and increased adiposity pose a serious threat to public health. Starting from the assumption that aging and obesity may have shared underpinnings, we investigated the antiobesogenic potential of a successful longevity intervention, the mTORC1 inhibitor rapamycin. We find that rapamycin prevents diet-induced obesity in mice and increases the activity of C/EBP-β LAP, a transcription factor that regulates the metabolic shift to lipid catabolism observed in response to calorie restriction. Independent activation of C/EBP-β LAP with the antiretroviral drug adefovir dipivoxil recapitulates the anti-obesogenic effects of rapamycin without reducing signaling through mTORC1 and increases markers of fat catabolism in the liver. Our findings support a model that C/EBP-β LAP acts downstream of mTORC1 signaling to regulate fat metabolism and identifies a novel drug that may be exploited to treat obesity and decrease the incidence of age-related disease.

High-fat diet increases gliosis and immediate early gene expression in APOE3 mice, but not APOE4 mice

Background

APOE4 is the strongest genetic risk factor for Alzheimer’s disease (AD), and obesity is a strong environmental risk factor for AD. These factors result in multiple central nervous system (CNS) disturbances and significantly increase chances of AD. Since over 20% of the US population carry the APOE4 allele and over 40% are obese, it is important to understand how these risk factors interact to affect neurons and glia in the CNS.

Methods

We fed male and female APOE3 and APOE4 knock-in mice a high-fat diet (HFD-45% kcal fat) or a "control" diet (CD-10% kcal fat) for 12 weeks beginning at 6 months of age. At the end of the 12 weeks, brains were collected and analyzed for gliosis, neuroinflammatory genes, and neuronal integrity.

Results

APOE3 mice on HFD, but not APOE4 mice, experienced increases in gliosis as measured by GFAP and Iba1 immunostaining. APOE4 mice on HFD showed a stronger increase in the expression of Adora2a than APOE3 mice. Finally, APOE3 mice on HFD, but not APOE4 mice, also showed increased neuronal expression of immediate early genes cFos and Arc.

Conclusions

These findings demonstrate that APOE genotype and obesity interact in their effects on important processes particularly related to inflammation and neuronal plasticity in the CNS. During the early stages of obesity, the APOE3 genotype modulates a response to HFD while the APOE4 genotype does not. This supports a model where early dysregulation of inflammation in APOE4 brains could predispose to CNS damages from various insults and later result in the increased CNS damage normally associated with the APOE4 genotype.

Regulation of cold-induced thermogenesis by the RNA binding protein FAM195A

Homeothermic vertebrates produce heat in cold environments through thermogenesis, in which brown adipose tissue (BAT) increases mitochondrial oxidation along with uncoupling of the electron transport chain and activation of uncoupling protein 1 (UCP1). Although the transcription factors regulating the expression of UCP1 and nutrient oxidation genes have been extensively studied, only a few other proteins essential for BAT function have been identified. We describe the discovery of FAM195A, a BAT-enriched RNA binding protein, which is required for cold-dependent thermogenesis in mice. FAM195A knockout (KO) mice display whitening of BAT and an inability to thermoregulate. In BAT of FAM195A KO mice, enzymes involved in branched-chain amino acid (BCAA) metabolism are down-regulated, impairing their response to cold. Knockdown of FAM195A in brown adipocytes in vitro also impairs expression of leucine oxidation enzymes, revealing FAM195A to be a regulator of BCAA metabolism and a potential target for metabolic disorders.

Deletion of Rptor in Preosteoblasts Reveals a Role for the Mammalian Target of Rapamycin Complex 1 (mTORC1) Complex in Dietary-Induced Changes to Bone Mass and Glucose Homeostasis in Female Mice

The mammalian target of rapamycin complex 1 (mTORC1) complex is the major nutrient sensor in mammalian cells that responds to amino acids, energy levels, growth factors, and hormones, such as insulin, to control anabolic and catabolic processes. We have recently shown that suppression of the mTORC1 complex in bone‐forming osteoblasts (OBs) improved glucose handling in male mice fed a normal or obesogenic diet. Mechanistically, this occurs, at least in part, by increasing OB insulin sensitivity leading to upregulation of glucose uptake and glycolysis. Given previously reported sex‐dependent differences observed upon antagonism of mTORC1 signaling, we investigated the metabolic and skeletal effects of genetic inactivation of preosteoblastic‐mTORC1 in female mice. Eight‐week‐old control diet (CD)‐fed Rptor_ob^−/− mice had a low bone mass with a significant reduction in trabecular bone volume and trabecular number, reduced cortical bone thickness, and increased marrow adiposity. Despite no changes in body composition, CD‐fed Rptor_ob^−/− mice exhibited significant lower fasting insulin and glucose levels and increased insulin sensitivity. Upon high‐fat diet (HFD) feeding, Rptor_ob^−/− mice were resistant to a diet‐induced increase in whole‐body and total fat mass and protected from the development of diet‐induced insulin resistance. Notably, although 12 weeks of HFD increased marrow adiposity, with minimal changes in both trabecular and cortical bone in the female control mice, marrow adiposity was significantly reduced in HFD‐fed Rptor_ob^−/− compared to both HFD‐fed control and CD‐fed Rptor_ob^−/− mice. Collectively, our results demonstrate that mTORC1 function in preosteoblasts is crucial for skeletal development and skeletal regulation of glucose homeostasis in both male and female mice. Importantly, loss of mTORC1 function in OBs results in metabolic and physiological adaptations that mirror a caloric restriction phenotype (under CD) and protects against HFD‐induced obesity, associated insulin resistance, and marrow adiposity expansion. These results highlight the critical contribution of the skeleton in the regulation of whole‐body energy homeostasis. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Cardiovascular Benefits and Lipid Profile Changes 5 Years After Bariatric Surgery: A Comparative Study Between Sleeve Gastrectomy and Roux-en-Y Gastric Bypass

INTRODUCTION

Visceral adipose tissue has been linked with cardiovascular events. Visceral adiposity index (VAI) is a routinely applicable tool for evaluation of visceral adipose dysfunction and linked to 10 year-cardiovascular risk. No previous studies have evaluated the changes over time of the VAI in patients who underwent different types of bariatric surgery.

MATERIALS AND METHODS

We reviewed data of 42 patients who underwent laparoscopic sleeve gastrectomy (LSG) and 61 patients who underwent laparoscopic Roux-en-Y gastric bypass (LRYGB). VAI, lipid profile, and several anthropometric variables were measured before and after 5 years following surgery.

RESULTS

During the studied time period, the BMI was similar between LSG and LRYGB patients (34.1 vs 31.6; p = 0.191), but the percentage of total weight loss (%TWL) for LRYGB was significantly higher than LSG (31.3% vs 23.0%; p < 0.001). LRYGB patients had a significant improvement of all lipid parameters evaluated over time, while LSG patients experienced only a reduction in triglycerides (TG) levels and an increase in HDL cholesterol (HDL-C). VAI values were similar in the two groups at baseline as well at the last follow-up point (5-year VAI, LSG: 0.93, RYGB: 0.93; p = 0.951). At multivariate regression analysis, 5-year-%TWL was the only independent predictor of a greater amount of VAI reduction over time.

CONCLUSION

Bariatric surgery, independent of the type of surgical procedure, decreases the cardiovascular disease (CVD) risks due to weight loss and improvement of lipid parameters. VAI could be a useful tool to better identify eligible patients for bariatric surgery and to determine the success of surgery.

Metabolic Stress Alters Antioxidant Systems, Suppresses the Adiponectin Receptor 1 and Induces Alzheimer's Like Pathology in Mice Brain

Oxidative stress and insulin resistance play major roles in numerous neurodegenerative diseases, including Alzheimer’s disease (AD). A high-fat diet induces obesity-associated oxidative stress, neuronal insulin resistance, microglial activation, and neuroinflammation, which are considered important risk factors for neurodegeneration. Obesity-related metabolic dysfunction is a risk factor for cognitive decline. The present study aimed to elucidate whether chronic consumption of a high-fat diet (HFD; 24 weeks) can induce insulin resistance, neuroinflammation, and amyloid beta (Aβ) deposition in mouse brains. Male C57BL/6N mice were used for a high-fat diet (HFD)-induced pre-clinical model of obesity. The protein expression levels were examined via Western blot, immunofluorescence, and the behavior analysis was performed using the Morris water maze test. To obtain metabolic parameters, insulin sensitivity and glucose tolerance tests were performed. We found that metabolic perturbations from the chronic consumption of HFD elevated neuronal oxidative stress and insulin resistance through adiponectin receptor (AdipoR1) suppression in HFD-fed mice. Similarly, our in vitro results also indicated that knockdown of AdipoR1 in the embryonic mouse hippocampal cell line mHippoE-14 leads to increased oxidative stress in neurons. In addition, HFD markedly increased neuroinflammatory markers’ glial activation in the cortex and hippocampus regions of HFD mouse brains. More importantly, we observed that AdipoR1 suppression increased the amyloidogenic pathway both in vivo and in vitro. Furthermore, deregulated synaptic proteins and behavioral deficits were observed in the HFD mouse brains. Taken together, our findings suggest that excessive consumption of an HFD has a profound impact on brain function, which involves the acceleration of cognitive impairment due to increased obesity-associated oxidative stress, insulin resistance, and neuroinflammation, which ultimately may cause early onset of Alzheimer’s pathology via the suppression of AdipoR1 signaling in the brain.

The prevalence of metabolic syndrome among Iranian bakers

BACKGROUND

Metabolic syndrome (MetS) is a group of risk factors that are associated with increased risk for atherosclerotic cardiovascular disease.

OBJECTIVE

The objective of this study was to determine the prevalence of metabolic syndrome and its individual components among Iranian bakery workers.

METHODS

A cross-sectional study enrolling 163 randomly selected bakery workers from Semnan province (Northeast Iran), was conducted in 2017. A standard questionnaire was used for data collection. Analyses were performed using t-test, one-way ANOVA and Latent Class Analysis (LCA) in R software.

RESULTS

The prevalence of MetS was 19.8% among bakery workers. More bakery workers with MetS had no regular exercise (p = 0.001) and worked more than eight hours a day (p = 0.001). In this study, the International Diabetes Federation (IDF) diagnostic criteria had more agreement with the American Heart Association (AHA) (49.1%) than the World Health Organization (WHO) and Adult Treatment Panel (ATP) criteria. Also, the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATPIII) had the highest sensitivity for diagnosing MetS. The sensitivity of the four diagnostic methods, WHO, IDF, ATP and AHA, were 45.2%, 61.7%, 67.9% and 64.8%; and their specificity were 98.2%, 100%, 100% and 100%, respectively.

CONCLUSION

The prevalence of MetS is high among bakery workers in Iran. Increased physical activity and intake of fruit and vegetables are recommended for the prevention of MetS.

A 2-Min Transient Ischemia Confers Cerebral Ischemic Tolerance in Non-Obese Gerbils, but Results in Neuronal Death in Obese Gerbils by Increasing Abnormal mTOR Activation-Mediated Oxidative Stress and Neuroinflammation

A brief episode of transient ischemia (TI) can confer cerebral ischemic tolerance against a subsequent severer TI under standard condition. The brain under obesity’s conditions is more sensitive to ischemic injury. However, the impact of a brief episode of TI under obesity’s conditions has not been fully addressed yet. Thus, the objective of this study was to determine the effect of a brief TI in the hippocampus of high-fat diet (HFD)-induced obese gerbils and related mechanisms. Gerbils were maintained on HFD or normal diet (ND) for 12 weeks and subjected to 2 min TI. HFD gerbils were heavier, with higher blood glucose, serum total cholesterol, triglycerides, and leptin levels. Massive loss of pyramidal neurons occurred in the hippocampal cornu ammonis 1 (CA1) field of HFD animals at 5 days after 2 min of TI, but 2 min of TI did not elicit death of pyramidal neurons in ND gerbils. The HFD group showed significantly increased levels of oxidative stress indicators (dihydroethidium and 4-hydroxynonenal) and proinflammatory cytokines (tumor necrosis factor-α and interleukin-1β) and microglial activation in pre- and/or post-ischemic phases compared to the ND group. Levels of mammalian target of rapamycin (mTOR) and phosphorylated-mTOR in the CA1 field of the HFD group were also significantly higher than the ND group. On the other hand, inhibition of mTOR activation by rapamycin (an allosteric mTOR inhibitor) significantly attenuated neuronal death induced by HFD, showing reduction of HFD-induced increases of oxidative stress indicators and proinflammatory cytokines, and microglia activation. Taken together, a brief episode of TI can evoke neuronal death under obesity’s conditions. It might be closely associated with an abnormal increase of mTOR activation-mediated, severe oxidative stress and neuroinflammation in pre- and/or post-ischemic phases.

Irisin Exerts Inhibitory Effect on Adipogenesis Through Regulation of Wnt Signaling

Irisin is an exercise-induced myokine known to induce adipocyte browning through induction of uncoupling protein 1. Recent studies have reported that irisin is also an adipokine. However, there is limiting evidence on the role of endogenous irisin from adipocytes. In this study we aim to elucidate the expression and secretion pattern of irisin during adipocyte differentiation and the role of endogenous and exogenous irisin on the adipogenic process. As such, recombinant irisin, plasmid expressing FNDC5 and small interfering RNA were utilized. Our results show that the gene expression of irisin precursor FNDC5 and irisin secretion increases at the early stage of adipogenesis. Both recombinant irisin treated cells and FNDC5-overexpressed cells resulted in inhibition of adipogenesis evidenced by downregulated C/EBPα, PPARγ, and FABP4 expression and reduced lipid accumulation. Further data showed that the inhibitory effect of irisin on adipogenesis is mediated though potentiation of Wnt expression, which is known to determine the fate of mesenchymal stem cells and regulate adipogenesis. Conversely, FNDC5 knockdown cells showed downregulated Wnt expression, but failed to further induce adipogenesis. This study suggests that both exogenous and endogenous irisin is able to inhibit adipogenesis and that activation of Wnt and subsequent repression of transcription factors is partly involved in this process. This provides a novel insight on the local effect of irisin on adipocytes and additional benefit to protect against obesity-related metabolic disorders.

Anti-obesity Activity of Ethanol Extract from Bitter Melon in Mice Fed High-Fat Diet

In many cases, obesity is associated with metabolic disorders. Recently, natural compounds that may be beneficial for improving obesity have received increasing attention. Bitter melon has received attention as a diabetes treatment. NAD⁺-dependent deacetylase (Sirtuin 1, SIRT1) has emerged as a novel therapeutic target for metabolic diseases. In this study, ethanol extract of bitter melon (BME) suppressed adipocyte differentiation and significantly increased the expression of SIRT1 in fully differentiated 3T3-L1 cells. Moreover, it enhanced the activation of AMP-activated protein kinase (AMPK). In high-fat diet (HFD)-fed induced-obesity mice, BME suppressed HFD-induced increases in body weight and white adipose tissue (WAT) weight. BME also increased the expression of SIRT1 and suppressed peroxisome proliferator-activated receptor and sterol regulatory element binding protein 1 expressions of WAT from HFD-fed mice. These findings suggest that BME prevents obesity by activating the SIRT1 and AMPK pathway and that it may be a useful dietary supplement for preventing obesity.

Disparities and drivers of early age at diagnosis of congestive heart failure in the USA

AIM

Heart failure (HF) constitutes a major public health problem in the USA due to its high morbidity and mortality. Age at diagnosis of HF would refine burden quantification, budgeting, disease surveillance and assessment of interventions. We set out to determine the median age at diagnosis of HF and drivers of young age at diagnosis among patients 20 years or older in the USA.

METHODS AND RESULTS

We utilized NHANES data collected across five survey cycles (2007-2016). Included were individuals aged 20 to 80 years diagnosed of HF with valid entries for age at diagnosis. Differences in age at diagnosis between groups and major drivers for younger age at diagnosis were assessed using linear regression models with p-values <0.05 considered statistically significant. The prevalence of HF in the USA was 2.44% with a median age at diagnosis of 59 years (IQR 47-70). Non-Hispanic (NH) Blacks -4.94 years (95% CI -7.95 to -1.93), individuals living below the poverty line -5.79 years (95% CI -10.36 to -1.01), obese persons -5.63 years (95% CI -8.35 to -2.92), individuals without health insurance -4.31 years (95% CI -7.87 to -0.75) and those without hypertension -3.99 years (95% CI -7.19 to -0.78) were diagnosed at significantly younger ages than their respective counterparts.

CONCLUSION

The median age at diagnosis of HF in the USA is 59 years. NH Blacks, living in poverty, lack of health insurance and obesity are the main drivers of early age at diagnosis of HF in the USA.

Potential role of E4orf1 protein in aging-associated impairment in glycemic control

Aging constitutes a major risk factor for the development of type-2 diabetes (T2D) where glucose tolerance declines with age, resulting in a high prevalence of T2D and impaired glucose tolerance in the elderly population. Currently more than half of the 20 million U.S. adults with T2D are above the age of 60, and the largest increase in T2D prevalence is expected in the elderly. Obesity is a causative factor for T2D associated insulin resistance and hyperglycemia. Furthermore, the aging process is accelerated by hyperglycemia and effective treatment options are limited for the vulnerable aging population. One of the mechanisms contributing to aging associated hyperglycemia is resistance to insulin-mediated glucose disposal. Chronic hyperglycemia also accelerates aging by increasing pro-inflammatory milieu leading to impaired immune function. Although currently available anti-diabetic agents improve glycemic control, they have potential serious side effects in some cases. Therefore, additional and better drugs are urgently needed for treatment of insulin resistance and aging associated health risk factors. This review presents the novel use of a microbial protein, E4orf1 as a potential anti-diabetic agent, which functions independent of insulin and obesity, highlighting the role of unique sources for future drug development.

The antioxidant activity of steamed ginger and its protective effects on obesity induced by high-fat diet in C57BL/6J mice

BACKGROUND/OBJECTIVES

Ginger, a root vegetable, is known to have antioxidant and antiobesity effects. Preparation, such as by steaming, can affect the chemical composition of prepared root vegetables or herbs and can change their functional activities. In the present study, we investigated the protective effects of steamed ginger against oxidative stress and steatosis in C57BL/6J mice fed a high-fat diet.

MATERIALS/METHODS

The levels of polyphenols and flavonoids in two different extracts of steamed ginger, i.e., water extract (SGW) and ethanolic extract (SGE); as well, their antioxidant activities were examined. Forty male C57BL/6J mice were fed a normal diet (ND, n = 10), high-fat diet (HFD, 60% fat, w/w, n = 10), HFD supplemented with 200 mg/kg of SGE or garcinia (GAR) by weight (SGED or GARD, respectively, n = 10) for 12 weeks. Serum chemistry was examined, and the expressions of genes involved in lipid metabolism were determined in the liver. Histological analysis was performed to identify lipid accumulations in epididymal fat pads and liver.

RESULTS

The SGE had higher contents of polyphenols and flavonoids and higher DPPH and ABTS⁺ free radical scavenging activities compared to those of SGW. Treatment with SGE or GAR significantly decreased the HFD-induced weight gain. Both SGE and GAR significantly reduced the high serum total cholesterol (TC), triglyceride (TG) and low-density lipoprotein levels induced by HFD. Compared to ND, HFD significantly increased hepatic TC and TG levels. SGE or GAR supplementation significantly decreased the increase of hepatic lipids by HFD. Interestingly, SGE had a more significant effect in reducing hepatic TC and TG levels than GAR. Furthermore, hepatic genes involved in lipogenesis and lipolysis were altered in both the SGED and GARD groups.

CONCLUSIONS

The present study indicates that steamed ginger supplementation can decrease plasma TC and TG and can inhibit liver steatosis by regulating the expressions of hepatic genes.

Testing the association of serum uric acid levels with behavioral and clinical characteristics in subjects with major affective disorders: A cross-sectional study

Previous research has hypothesized a role for serum uric acid as a marker of mental disorders and related behaviors, possibly due to its link with purinergic transmission and antioxidant activity. We tested the association of serum uric acid levels with specific behavioral and clinical characteristics in 99 individuals suffering from major affective disorders. Subjects were assessed and interviewed using the Kessler Psychological Distress Scale, the Columbia-Suicide Severity Rating Scale, the Modified Overt Aggression Scale, and the Barratt Impulsiveness Scale. We found that psychological distress and suicidal ideation severity were associated with lower uric acid serum levels. On the other hand, verbal aggression and history of violence were associated with higher levels of serum uric acid. However, according to linear regression analyses, there were no behavioral and clinical characteristics independently associated with serum uric acid. Serum uric acid levels were influenced by creatinine and BMI, as well as, possibly, by white blood cells count and gender. Despite some limitations, these results suggest that no behavioral / clinical features are associated with variations of serum uric acid, which rather seem attributable to specific biochemical and metabolic parameters. Nevertheless, the role of purinergic system in different mental disorders and behavioral abnormalities, deserves further research.

G-Protein-Coupled Estrogen Receptor (GPER) and Sex-Specific Metabolic Homeostasis

Obesity and metabolic syndrome display disparate prevalence and regulation between males and females. Human, as well as rodent, females with regular menstrual/estrous cycles exhibit protection from weight gain and associated chronic diseases. These beneficial effects are predominantly attributed to the female hormone estrogen, specifically 17β-estradiol (E2). E2 exerts its actions via multiple receptors, nuclear and extranuclear estrogen receptor (ER) α and ERβ, and the G-protein-coupled estrogen receptor (GPER, previously termed GPR30). The roles of GPER in metabolic homeostasis are beginning to emerge but are complex and remain unclear. The discovery of GPER-selective pharmacological agents (agonists and antagonists) and the availability of GPER knockout mice have significantly enhanced our understanding of the functions of GPER in normal physiology and disease. GPER action manifests pleiotropic effects in metabolically active tissues such as the pancreas, adipose, liver, and skeletal muscle. Cellular and animal studies have established that GPER is involved in the regulation of body weight, feeding behavior, inflammation, as well as glucose and lipid homeostasis. GPER deficiency leads to increased adiposity, insulin resistance, and metabolic dysfunction in mice. In contrast, pharmacologic stimulation of GPER in vivo limits weight gain and improves metabolic output, revealing a promising novel therapeutic potential for the treatment of obesity and diabetes.

Familial aggregation and linkage analysis with covariates for metabolic syndrome risk factors

BACKGROUND

Mechanisms of metabolic syndrome (MetS) causation are complex, genetic and environmental factors are important factors for the pathogenesis of MetS In this study, we aimed to evaluate familial and genetic influences on metabolic syndrome risk factor and also assess association between FTO (rs1558902 and rs7202116) and CETP(rs1864163) genes' single nucleotide polymorphisms (SNP) with low HDL_C in the Tehran Lipid and Glucose Study (TLGS).

MATERIALS AND METHODS

The design was a cross-sectional study of 1776 members of 227 randomly-ascertained families. Selected families contained at least one affected metabolic syndrome and at least two members of the family had suffered a loss of HDL_C according to ATP III criteria. In this study, after confirming the familial aggregation with intra-trait correlation coefficients (ICC) of Metabolic syndrome (MetS) and the quantitative lipid traits, the genetic linkage analysis of HDL_C was performed using conditional logistic method with adjusted sex and age.

RESULTS

The results of the aggregation analysis revealed a higher correlation between siblings than between parent-offspring pairs representing the role of genetic factors in MetS. In addition, the conditional logistic model with covariates showed that the linkage results between HDL_C and three marker, rs1558902, rs7202116 and rs1864163 were significant.

CONCLUSIONS

In summary, a high risk of MetS was found in siblings confirming the genetic influences of metabolic syndrome risk factor. Moreover, the power to detect linkage increases in the one parameter conditional logistic model regarding the use of age and sex as covariates.

White matter microstructure and cognitive decline in metabolic syndrome: a review of diffusion tensor imaging

Metabolic syndrome is a cluster of cardiovascular risk factors defined by the presence of abdominal obesity, glucose intolerance, hypertension and/or dyslipidemia. It is a major public health epidemic worldwide, and a known risk factor for the development of cognitive dysfunction and dementia. Several studies have demonstrated a positive association between the presence of metabolic syndrome and worse cognitive outcomes, however, evidence of brain structure pathology is limited. Diffusion tensor imaging has offered new opportunities to detect microstructural white matter changes in metabolic syndrome, and a possibility to detect associations between functional and structural abnormalities. This review analyzes the impact of metabolic syndrome on white matter microstructural integrity, brain structure abnormalities and their relationship to cognitive function. Each of the metabolic syndrome components exerts a specific signature of white matter microstructural abnormalities. Metabolic syndrome and its components exert both additive/synergistic, as well as, independent effects on brain microstructure thus accelerating brain aging and cognitive decline.

Transforming Growth Factor β/Activin signaling in neurons increases susceptibility to starvation

Animals rely on complex signaling network to mobilize its energy stores during starvation. We have previously shown that the sugar-responsive TGFβ/Activin pathway, activated through the TGFβ ligand Dawdle, plays a central role in shaping the post-prandial digestive competence in the Drosophila midgut. Nevertheless, little is known about the TGFβ/Activin signaling in sugar metabolism beyond the midgut. Here, we address the importance of Dawdle (Daw) after carbohydrate ingestion. We found that Daw expression is coupled to dietary glucose through the evolutionarily conserved Mio-Mlx transcriptional complex. In addition, Daw activates the TGFβ/Activin signaling in neuronal populations to regulate triglyceride and glycogen catabolism and energy homeostasis. Loss of those neurons depleted metabolic reserves and rendered flies susceptible to starvation.

Obesity and metabolic dysfunction severely influence prostate cell function: role of insulin and IGF1

Obesity is a major health problem that courses with severe comorbidities and a drastic impairment of homeostasis and function of several organs, including the prostate gland (PG). The endocrine–metabolic regulatory axis comprising growth hormone (GH), insulin and IGF1, which is drastically altered under extreme metabolic conditions such as obesity, also plays relevant roles in the development, modulation and homeostasis of the PG. However, its implication in the pathophysiological interplay between obesity and prostate function is still to be elucidated. To explore this association, we used a high fat–diet obese mouse model, as well as in vitro primary cultures of normal‐mouse PG cells and human prostate cancer cell lines. This approach revealed that most of the components of the GH/insulin/IGF1 regulatory axis are present in PGs, where their expression pattern is altered under obesity conditions and after an acute insulin treatment (e.g. Igfbp3), which might have some pathophysiological implications. Moreover, our results demonstrate, for the first time, that the PG becomes severely insulin resistant under diet‐induced obesity in mice. Finally, use of in vitro approaches served to confirm and expand the conception that insulin and IGF1 play a direct, relevant role in the control of normal and pathological PG cell function. Altogether, these results uncover a fine, germane crosstalk between the endocrine–metabolic status and the development and homeostasis of the PG, wherein key components of the GH, insulin and IGF1 axes could play a relevant pathophysiological role.

Resistin mediates tomato and broccoli extract effects on glucose homeostasis in high fat diet-induced obesity in rats

Background

Resistin is an adipocyte hormone that regulates glucose metabolism. Elevated levels of resistin may cause insulin resistance. This may link obesity, and increased fat mass to type II diabetes and insulin resistance. We hypothesized that treatment with tomato and broccoli extracts regulates glucose homeostasis via modulation of resistin levels in high fat diet-induced obesity rats (HFD).

Methods

Forty-eight male albino rats were divided into 8 groups as follows: control, HFD, stop fat diet (SD), Tomato 200 mg/kg (T200), Tomato 400 mg/kg (T400), Broccoli 200 mg/kg (B200), Broccoli 400 mg/kg (B400), and Chromax (CX). Treatment continued for 1 month. Serum levels of resistin, leptin, adiponectin, glucose and insulin were measured using ELISA and spectrophotometry.

Results

Serum levels of resistin were significantly reduced in the T 200, T 400, B 200, B 400 and CX groups to: 4.13 ± 0.22 ng/ml, 1.51 ± 0.04 ng/ml, 4.13 ± 0.22 ng/ml, 2.32 ± 0.15 ng/ml and 1.37 ± 0.03 ng/ml, respectively, compared to HFD group and SD group (P value < 0.0001). Non-significant differences were found between T 400, B 400 and CX groups. Serum levels of leptin were significantly reduced in the T 400 (22.7 ± 0.84 pg/ml) group compared to the B 400 (41 ± 2.45 Pg/ml) and CX groups (45.7 ± 2.91 Pg/ml), P value < 0.001. Serum levels of adiponectin were significantly increased in the T 400 group (131 ± 3.84 pg/ml) compared to the CX group (112 ± 4.77 pg/ml), P value < 0.01.

Conclusions

Our results demonstrate that tomato and broccoli extract treatment regulates glucose homeostasis via reduction of serum resistin and may be a useful non-pharmacological therapy for obesity.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-016-1203-0) contains supplementary material, which is available to authorized users.

Impact of increased intramuscular perfusion heterogeneity on skeletal muscle microvascular hematocrit in the metabolic syndrome

OBJECTIVE

To determine HMV and PS in skeletal muscle of OZR and evaluate the impact of increased microvascular perfusion heterogeneity on mass transport/exchange.

METHODS

The in situ gastrocnemius muscle from OZR and LZR was examined under control conditions and following pretreatment with TEMPOL (antioxidant)/SQ-29548 (PGH2 /TxA2 receptor antagonist), phentolamine (adrenergic antagonist), or all agents combined. A spike input of a labeled blood tracer cocktail was injected into the perfusing artery. Tracer washout was analyzed using models for HMV and PS. HT was determined in in situ cremaster muscle of OZR and LZR using videomicroscopy.

RESULTS

HMV was decreased in OZR versus LZR. While TEMPOL/SQ-29548 or phentolamine had minor effects, treatment with all three agents improved HMV in OZR. HT was not different between strains, although variability was increased in OZR, and normalized following treatment with all three agents. PS was reduced in OZR and was not impacted by intervention.

CONCLUSIONS

Increased microvascular perfusion heterogeneity in OZR reduces HMV in muscle vascular networks and increases its variability, potentially contributing to premature muscle fatigue. While targeted interventions can ameliorate this, the reduced microvascular surface area is not acutely reversible.

Stair descending exercise using a novel automatic escalator: effects on muscle performance and health-related parameters

A novel automatic escalator was designed, constructed and used in the present investigation. The aim of the present investigation was to compare the effect of two repeated sessions of stair descending versus stair ascending exercise on muscle performance and health-related parameters in young healthy men. Twenty males participated and were randomly divided into two equal-sized groups: a stair descending group (muscle-damaging group) and a stair ascending group (non-muscle-damaging group). Each group performed two sessions of stair descending or stair ascending exercise on the automatic escalator while a three week period was elapsed between the two exercise sessions. Indices of muscle function, insulin sensitivity, blood lipid profile and redox status were assessed before and immediately after, as well as at day 2 and day 4 after both exercise sessions. It was found that the first bout of stair descending exercise caused muscle damage, induced insulin resistance and oxidative stress as well as affected positively blood lipid profile. However, after the second bout of stair descending exercise the alterations in all parameters were diminished or abolished. On the other hand, the stair ascending exercise induced only minor effects on muscle function and health-related parameters after both exercise bouts. The results of the present investigation indicate that stair descending exercise seems to be a promising way of exercise that can provoke positive effects on blood lipid profile and antioxidant status.

Metabolic Syndrome and its Associated Risk Factors in Healthy Adults: APopulation-Based Study in Iran

BACKGROUND

Metabolic syndrome includes obesity, hypertriglyceridemia, glucose intolerance, hypertension, and lipid profile abnormalities. The risk of cardiovascular diseases with this syndrome is higher than with each of its components alone. Currently, cardiovascular disorders have a great burden and a high mortality rate in Iran. This study was performed to determine prevalence of the metabolic syndrome and its underlying components in an urban population of Tehran.

METHODS

The 25-64-year-old individuals in the Population Laboratory of Tehran University of Medical Sciences were studied through a single-stage cluster sampling; 1573 participants were studied. The response rate was 94.08%. The study was designed according to the World Health Organization (WHO) MONICA (Multinational Monitoring of Trends and Determinants in Cardiovascular Disease) project using the Adult Treatment Panel III (ATPIII) criteria. The parameters used for the risk analysis were waist circumference, fasting serum triglycerides, high density lipoprotein (HDL)-cholesterol, blood pressure, and fasting plasma glucose.

RESULTS

The crude prevalence rate of the metabolic syndrome was 29.9% (age-adjusted: 27.5%). The prevalence was significantly higher in women than in men (35.9% vs. 20.3%). The prevalence increased with age in both genders. In the whole population, 88% met at least one of the metabolic syndrome criteria. The most prevalent metabolic abnormalities were hypertriglyceridemia and hypertension that were present in more than half of the population. Also, means of HDL was significantly higher in metabolic syndrome positive group. By further adjustment for age and sex in multivariate analysis, the difference disappeared and even HDL-C level was slightly lower in people with metabolic syndrome.

CONCLUSIONS

RESULTS demonstrate high metabolic syndrome rate among target population especially in women. In view of correlation between metabolic syndrome and cardiovascular disease, it must be the priority for interventional preventive measures.

Influence of obesity and metabolic dysfunction on the endothelial control in the coronary circulation

Diseases of the coronary circulation remain the leading cause of death in Western society despite impressive advances in diagnosis, pharmacotherapy and post-event management. Part of this statistic likely stems from a parallel increase in the prevalence of obesity and metabolic dysfunction, both significant risk factors for coronary disease. Obesity and diabetes pose unique challenges for the heart and their impact on the coronary vasculature remains incompletely understood. The vascular endothelium is a major interface between arterial function and the physical and chemical components of blood flow. Proper function of the endothelium is necessary to preserve hemostasis, maintain vascular tone and limit the extent of vascular diseases such as atherosclerosis. Given its central role in vascular health, endothelial dysfunction has been the source of considerable research interest in diabetes and obesity. In the current review, we will examine the pathologic impact of obesity and diabetes on coronary function and the extent to which these two factors impact endothelial function. This article is part of a Special Issue entitled "Coronary Blood Flow".

Waist-to-height ratio, an optimal predictor for obesity and metabolic syndrome in Chinese adults

OBJECTIVE

Anthropometric indices to obesity were evaluated as predictors of metabolic syndrome risk factors. Our purpose was to explore an optimal or more reliable anthropometric indicator and optimal cut-off points for obesity on metabolic syndrome in Chinese adults.

PARTICIPANTS AND METHODS

The survey was conducted involving 2947 participants, aged 20 or above with cross-sectional study of population. The predictive validity and optimal cut-off values were analyzed by receiver operating characteristic (ROC) curves, area under curve (AUC) and the largest Youden's index (sensitivity + specificity - 1) by gender group, respectively. Kappa value showed diagnostic consistency.

RESULTS

According to the criteria of CDS 2004, IDF 2005 and AHA/NHLBI 2005, the prevalence of metabolic syndrome was 10.32%, 9.64% and 16.12% respectively, which indicated that the prevalence was higher in men than in women and increased with age (P < 0.05). The BMI, WC, WHR and WHtR in metabolic syndrome patients were greater than those in healthy volunteers and the indices in men were higher than those in women. With adjusted age and gender, the partial correlation coefficient for BMI-WC, BMI-WHR and BMI-WHtR was 0.7991, 0.5278 and 0.8196, respectively (P < 0.05). The area under curves (AUCs) of receiver operating characteristic (ROC) curves for WHtR was larger (P < 0.05) than that for WC and WHR. The cut-point of WHtR was approximately 0.5 in both genders with a satisfactory balance between sensitivity and specificity, where the Kappa (k) value for WHtR-BMI was higher than that for WHtR-WHR, and WHtR-WC.

CONCLUSIONS

The results indicated that WHtR might be an optimal anthropometric predictor of metabolic syndrome risk factors and the cut-point of WHtR was approximately 0.50 in both genders of Chinese adults.

Physical therapy in the 21st century (Part I): toward practice informed by epidemiology and the crisis of lifestyle conditions

Part I of this two-part introduction to this Special Issue on the practice of physical therapy in the 21st century outlines the epidemiological basis and rationale for evidence-informed physical therapy practice for addressing contemporary health priorities. This evidence emanates from the definition of health by the World Health Organization (WHO) and the International Classification of Functioning (ICF), and WHO and other international databases on the prevalence of lifestyle conditions. Lifestyle conditions include ischemic heart disease, smoking-related conditions, hypertension and stroke, obesity, diabetes, and cancer. Epidemiological data combined with evidence supporting the effectiveness of noninvasive interventions related to physical therapy to address these priorities (e.g., health education and exercise) are highly consistent with the promotion of health and wellness and the ICF. Given their commitment to exploiting effective noninvasive interventions, physical therapists are in a preeminent position to focus on prevention of these disabling and lethal conditions in every client or patient, their cure in some cases, as well as their management. Thus, a compelling argument can be made that clinical competencies in 21st century physical therapy need to include assessment of smoking and smoking cessation (or at least its initiation), basic nutritional assessment and counseling, recommendations for physical activity and exercise, stress assessment and basic stress reduction recommendations, and sleep assessment and basic sleep hygiene recommendations. The physical therapist can then make an informed clinical judgment regarding whether a client or patient needs to be referred to another professional related to one or more of these specialty areas. The prominence of physical therapy as an established health care profession and its unique pattern of practice (prolonged visits over prolonged periods of time) attest further to the fact that physical therapists are uniquely qualified to lead in the assault on lifestyle conditions. Evidence-based physical therapy practiced within the context of epidemiological indicators (i.e., evidence-informed practice) maximally empowers clinicians to promote lifelong health in every person and in turn, the health of communities. This vision of physical therapy's leading role in health promotion and health care in the 21st century holds the promise of reducing the need for invasive health interventions (drugs and surgery). Part II of this introduction describes evidence-based physical therapy practice within this context of evidence-informed practice.

Westernized-like-diet-fed rats: effect on glucose homeostasis, lipid profile, and adipocyte hormones and their modulation by rosiglitazone and glimepiride

Wersternized diet, containing high fat diet intake combined with high consumption of softdrinks, is accused with the emerge of modern epidemic obesity and diabesity. Therefore, we aimed to study the effect of this diet combination on the homeostasis of glucose, lipids, and some adipohormones in rats and to simulate the metabolic perturbations induced by the unhealthy Westernized diet intake, leading to the development of type 2 diabetes. To achieve this, we divided male Wistar rats (80-120 g) into two main groups: the first was fed commercial normal fat diet and the second received an in-house-prepared high-fat diet (HFD), combined with fructose in drinking water for a period of 6 weeks, followed by a subdiabetogenic dose of streptozotocin (STZ) (35 mg/kg) to produce frank hyperglycemia. The effect of this diet alone or after 2 weeks of treatment with rosiglitazone or glimepiride on glucose homeostasis, lipid profile, and levels of resistin and leptin was studied. The HFD/fructose/STZ diet elevated fasting plasma glucose, fructosamine, insulin, and homeostasis model assessment (HOMA) index, as well as serum triglycerides (TGs), total cholesterol (TC), and low-density lipoprotein cholesterol, with a decrease in high-density lipoprotein cholesterol. Hepatic TG and TC levels, as well as serum activities of aspartate transaminase (AST), alanine transaminase (ALT), and lactate dehydrogenase (LDH), were increased, suggesting a diet-induced hepatic steatosis, beside the increased levels of serum resistin and leptin. Rosiglitazone corrected the altered parameters measured, except for liver TGs; similarly, glimepiride reinstated the inverted parameters but raised insulin level and, consequently, the HOMA index. These results show that this diet could be used to induce an effect that mimics human type 2 diabetes with its metabolic disturbances and is suitable for screening the antidiabetic agents used for management of this disease.

Inulin-enriched pasta affects lipid profile and Lp(a) concentrations in Italian young healthy male volunteers

BACKGROUND

Inulin has been suggested to have beneficial effects on lipids, especially on triglyceridemia. Few data are available about the effects of inulin on Lipoprotein(a), a low-density lipoprotein-like particle considered as an independent risk factor for atherosclerosis. Adding inulin to pasta could be a preventive strategy for delaying the onset of atherosclerosis.

AIM OF THE STUDY

was to evaluate the effects of inulin-enriched pasta on lipid profile and on Lipoprotein(a) in young healthy subjects.

METHODS

Twenty-two young healthy male volunteers entered a randomized double blind cross-over study consisting of a 2-weeks run-in period, a baseline assessment, two 5-weeks study periods (11% inulin-enriched or control pasta), and an 8-weeks wash-out period in between. Serum lipid concentrations were evaluated by routine biochemical analyses and plasma Lipoprotein(a) concentrations by ELISA. The size of apolipoprotein(a) isoforms was determined by Western blot and immunodetection.

RESULTS

Significant differences at baseline and in the treatment groups were found for HDL-cholesterol (P = 0.004), total cholesterol/HDL-cholesterol ratio (P = 0.006), triglycerides (P = 0.04), and Lipoprotein(a) (P = 0.02) concentrations (data analyzed by Friedman test). Dunn's multiple comparison test was used to assess the significance of differences between inulin-enriched pasta diet vs. baseline. HDL-cholesterol concentrations increased by 35.9%; total cholesterol/HDL-cholesterol ratio, triglycerides, and Lipoprotein(a) concentrations decreased by 22.2, 23.4, and 16.5% respectively.

CONCLUSIONS

Inulin-enriched pasta administration induced significant effects on lipid pattern parameters in young healthy volunteers, including a significant reduction in Lipoprotein(a) concentrations.

Hispanic and Asian pubertal girls have higher android/gynoid fat ratio than whites

OBJECTIVE

To examine differences in body size, composition, and distribution of body fat among Hispanic, white, and Asian adolescents.

RESEARCH METHODS AND PROCEDURES

This included cross-sectional data from the baseline sample of the Adequate Calcium Today trial. Participants included 180 Asian, 234 Hispanic, and 325 white girls 11.8 +/- 0.05 years of age from Arizona, California, Hawaii, Indiana, Ohio, and Nevada. Anthropometric and DXA measurements (Lunar Prodigy) were standardized across sites. Tanner pubertal stage was self-selected from line drawings. Physical activity was assessed by a validated questionnaire. Comparisons between ethnic groups were examined using contrasts in the context of a general linear model.

RESULTS

Controlling for pubertal stage and study site only, Asians weighed less than Hispanics and were shorter than Hispanics and whites. Controlling for pubertal stage, height, weight, and study site, Asians had shorter leg lengths, smaller waist circumference, longer trunk lengths, more lean mass, less total fat mass, and less gynoid fat mass than Hispanics and whites; Asians had larger bitrochanteric width than whites; Asians had smaller DXA-derived android fat mass than Hispanics; and whites had smaller mean android/gynoid fat ratio than Hispanics. However, whites had a smaller android/gynoid fat ratio than both Asians and Hispanics in a model that adjusted for ethnicity, pubertal stage, bitrochanteric width, waist circumference, trunk length, log of physical activity, and study site, which explained 77% of the variation.

DISCUSSION

Ethnic differences in fat distribution are partially explained by differences in skeletal dimensions.