Nutrition, insulin resistance and dysfunctional adipose tissue determine the different components of metabolic syndrome

Muscle-dependent regulation of adipose tissue function in long-lived growth hormone-mutant mice

Altered adipose tissue may contribute to the longevity of Snell dwarf and growth hormone receptor (GHR) knock-out mice. We report here that white (WAT) and brown (BAT) fat have elevated UCP1 in both kinds of mice, and that adipocytes in WAT depots turn beige/brown. These imply increased thermogenesis and are expected to lead to improved glucose control. Both kinds of long-lived mice show lower levels of inflammatory M1 macrophages and higher levels of anti-inflammatory M2 macrophages in BAT and WAT, with correspondingly lower levels of TNFα, IL-6, and MCP1. Experiments with mice with tissue-specific disruption of GHR showed that these adipocyte and macrophage changes were not due to hepatic IGF1 production nor to direct GH effects on adipocytes, but instead reflect GH effects on muscle. Muscles deprived of GH signals, either globally (GKO) or in muscle only (MKO), produce higher levels of circulating irisin and its precursor FNDC5. The data thus suggest that the changes in adipose tissue differentiation and inflammatory status seen in long-lived mutant mice reflect interruption of GH-dependent irisin inhibition, with consequential effects on metabolism and thermogenesis.

Glutathione S-transferase T1 and M1 null genotype distribution among non-alcoholic fatty liver disease patients and its association with cytokine and adipokine profiles

Aim of the study

Among the key genes involved in the development of non-alcoholic fatty liver disease (NAFLD) are genes encoding the synthesis of glutathione S-transferase (GST).

Material and methods

Deletion polymorphism of GSTT1 and GSTM1 genes was investigated in 104 NAFLD patients and 45 healthy individuals. Biochemical blood analysis, tumor necrosis factor-α (TNF-α), interleukin-10, leptin and adiponectin plasma levels were studied.

Results

The distribution of deletion vs. non-deletion genotypes of the GSTT1 gene in NAFLD patients was 18 (17.3%) vs. 86 (82.7%) patients and in healthy people it was 6 (13.3%) vs. 39 (86.7%) individuals. The genotype distribution of the GSTM1 gene was as follows: 52 (50.0%) NAFLD patients had null genotype vs. 52 patients (50.0%) with non-deletion genotype; in the control group - 23 (51.1%) vs. 22 (48.9%) individuals. Deletion of the GSTT1 gene in NAFLD patients was associated with twice as high (p = 0.01) TNF-α level in the blood as compared to patients with normal genotype. Higher concentration of leptin in blood by 37.1% (p = 0.04) was observed in patients with null genotype of the GSTM1 gene, as compared to those with normal genotype.

Conclusions

Deletion polymorphism of GSTT1 and GSTM1 genes distribution among NAFLD patients did not differ as compared to healthy individuals. Null-genotype GSTT1 gene carriers were characterized by higher TNF-α concentration and null-genotype GSTM1 gene carriers were characterized by elevated leptin level as compared to normal genotype carriers.

Fish oil reduces subclinical inflammation, insulin resistance, and atherogenic factors in overweight/obese type 2 diabetes mellitus patients: A pre-post pilot study

OBJECTIVE

Insulin resistance-associated obesity and type 2 diabetes mellitus (T2DM) are commonly accompanied with metabolic lipid abnormalities and are characterized by hypertriglyceridemia and low HDL-c levels (atherogenic index plasma, AIP). The primary molecular mechanism that is known to cause insulin resistance is chronic low-grade inflammation. Considering that omega-3 fatty acid reduces subclinical inflammation, we hypothesized that fish oil could affect insulin resistance and AIP. Therefore, the present study evaluated the effects of fish oil supplementation on the inflammatory, insulin resistance, and atherogenic factors in overweight/obese T2DM patients.

RESEARCH DESIGNS AND METHODS

In this study, we recruited 32 overweight and/or obese patients diagnosed with T2DM for over one year and who exhibited hypertriglyceridemia. These patients received fish oil supplementation (4.0 g/day) for eight weeks. Anthropometric and body composition measurements were obtained. In addition, blood samples were collected before and after omega-3 supplementation for the evaluation of lipid profile, glycemia, insulin, and inflammation.

RESULTS

As expected, patients showed reduction in the TNFα, IL-1β, and Il-6 levels after fish oil supplementation and showed improved insulin sensitivity (HOMA-IR) without observed alterations in anthropometric and body composition. These observations were followed by reduction in the levels of triglycerides and non-esterified fatty acids, increase in HDL cholesterol levels, and a significant reduction in triglycerides/HDL-c ratio, and total cholesterol/HDL-c ratio.

CONCLUSION

Fish oil supplementation is effective in reducing the levels of proinflammatory cytokines, improving insulin resistance, and reducing atherogenic factors in overweight/obese and T2DM patients independent of weight loss.

Oral gallic acid improve liver steatosis and metabolism modulating hepatic lipogenic markers in obese mice

INTRODUCTION

Gallic acid (GA) is a natural endogenous polyphenol found in a variety of fruits, vegetables and wines, with beneficial effects on the energetic homeostasis.

AIM

The present study aimed to investigate oral gallic acid effects on liver steatosis and hepatic lipogenesis markers in obese mice evaluating new possible molecular related mechanisms.

METHODS

Twenty-four Swiss male mice were divided into four groups and fed for 60 days with standard diet (ST), standard diet plus gallic acid (ST + GA), high-fat diet (HFD), and high-fat diet plus gallic acid (HFD + GA). We evaluated the relationship between body weight, food intake and serum levels of total cholesterol, triglycerides, insulin, aspartate and alanine transaminases. Liver histology was analyzed by hematoxylin and eosin staining. These results were accompanied by bioinformatics analyses. The acetyl-CoA carboxylase (ACC), sterol regulatory element binding protein-1 (SREBP-1) and fatty acid synthase (FAS) expression was assessed by quantitative real-time reverse transcriptase PCR (qRT-PCR).

RESULTS

The main findings of the present study showed that GA reduced liver steatosis, body weight and plasma insulin levels. Analyzes of hepatic steatosis related genes expression showed that ACC and FAS mRNA were significantly suppressed in liver of HFD + GA mice. These data was corroborated by bioinformatics analysis.

CONCLUSION

These data suggest an important clinical application of GA in the prevention and treatment of liver diseases.

Circulatory miRNA biomarkers of metabolic syndrome

AIMS

Circulatory microRNAs (c-miRNAs) exert important roles in the molecular dysregulation of cardio-metabolic diseases. However, little is known whether dysregulated miRNA expression occurs when risk factors are elevated, as in the metabolic syndrome (MetS). This study quantified c-miRNA expression in individuals with MetS compared to healthy, further examining the relationship of gene pathways with the underlying pathogenesis.

METHODS

Expression of 26 miRNAs was quantified in plasma from 40 women (20 healthy and 20 MetS) and 39 men (20 healthy and 19 MetS) by qPCR. In silico analysis was performed to investigate biological effects of the dysregulated miRNAs. Dysregulated miRNA expression was further validated in an independent cohort of 20 women (10 healthy and 10 MetS).

RESULTS

Regression model adjusted for age and sex identified miR-15a-5p, miR-17-5p, miR-370-3p and miR-375 as important predictors of MetS presence. Analysis of predictive miRNAs in the validation cohort strengthened the relationship with miR-15a-5p and miR-17-5p expression. These miRNAs share genes involved in the regulation of metabolic pathways including insulin, wnt, fatty acid metabolism and AMPK.

CONCLUSIONS

miR-15a-5p and miR-17-5p were identified as predictive biomarkers of MetS, irrespective of sexes, further demonstrating the relationship of c-miRNAs to known pathways of metabolic disturbances present in cardio-metabolic diseases.

The Dose-Response Associations of Sedentary Time with Chronic Diseases and the Risk for All-Cause Mortality Affected by Different Health Status: A Systematic Review and Meta-Analysis

PURPOSE

To determine the dose-response associations of sedentary behaviour with cardiovascular diseases (CVD), cancer, and all-cause mortality, and to examine whether the sedentary-associated all-cause mortality risk was affected by appearance of diabetes and hypertension, physical activity, and body mass index (BMI).

DESIGN

We carried out a systematic review and meta-analysis to search Medline, SportDiscus, and Web of Science for eligible studies.

SETTINGS

Prospective cohort studies that reported sedentary time and CVD, cancer, and mortality incidents.

MEASUREMENTS

Two authors independently extracted data based on predefined criteria. The effect estimates were evaluated by hazard ratios (HRs) with 95% confidences (CIs).

RESULTS

Twenty-four studies met the inclusion criteria. Sitting time showed dose-response associations with CVD, cancer, and all-cause mortality, with each 1-hour increment of sitting time daily accounting for HRs 1.04 (95% CIs 1.02-1.07), 1.01 (1.00-1.02), and 1.03 (1.02-1.03), respectively. The link between sitting time and CVD and all-cause mortality was non-linear (pnon-linear < 0.0001). The relationship between TV viewing and CVD and all-cause mortality was dose-dependent, with HRs 1.07 (1.06-1.09) and 1.04 (1.01-1.06) for per 1-hour increment of TV time every day, respectively. The regression was curved (pnon-linear < 0.0001). When the analysis was stratified by the percentage of diabetes and hypertension, BMI values, and physical activity levels, we found that higher BMI and a greater percentage of diabetes and hypertension further increased all-cause mortality risk in the most sedentary populations, whereas higher physical activity levels decreased it.

CONCLUSION

Sitting time and TV viewing significantly increased cardiovascular, cancer, and mortality risk; the associations were dose-dependent. More importantly, sedentary behaviour in combination with chronic diseases or high BMI increased all-cause mortality risk whereas physical activity was likely to alleviate the adverse associations.

Inadequacy of Vitamin D Nutritional Status in Individuals with Metabolically Unhealthy Obesity Phenotype: The Relevance of Insulin Resistance

PURPOSE

The aim was to evaluate 25(OH)D serum concentrations in metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUHO) and its relation with biochemical and clinical parameters in both groups according to homeostatic model assessment-insulin resistance (HOMA-IR) definition of the obesity phenotypes.

PATIENTS AND METHODS

Descriptive cross-sectional study was conducted with individuals of both genders. Anthropometric data [waist circumference, body mass index (BMI)] and metabolic parameters: blood glucose, glycated hemoglobin, insulin, lipid profile, calcium, phosphorus, parathyroid hormone (PTH) and high-sensitivity c-reactive protein (hs-CRP) and (25(OH)D) were obtained. The cutoff points for vitamin D deficiency and insufficiency were ≤20 and 21-29 ng/mL, respectively. Individuals were classified as MUHO according to HOMA-IR≥2.5.

RESULTS

This study comprised 232 individuals with obesity (BMI≥35 kg/m²; 42.6±4.7 kg/m²). The MUHO phenotype was observed in 76.7% of the population. The mean values of glucose (P<0.001), insulin (P<0.001), HOMA-IR (P<0.001), and triglycerides (P=0.049) were significantly higher in the MUHO than in the MHO phenotype group. The mean value of 25(OH)D showed a significant difference between the MHO and MUHO phenotype groups (P=0.011). Additionally, and in line, lower mean 25(OH)D values were found in the MUHO vs the MHO phenotype group in the deficiency (14.5±3.6 ng/mL/17.1±2.7 ng/mL, P=0.004) and insufficiency (24.5±2.9 ng/mL/25.7±2.6 ng/mL, P=0.077) 25(OH)D groups. An increase of 1 ng/mL of vitamin D increased in 1.051 (95% CI= 1.011-1.093, P=0.012) the odds of the healthy phenotype.

CONCLUSION

The highest prevalence of inadequacy of serum concentrations of 25(OH)D and greater severity of this deficiency in individuals with MUHO phenotype were observed. Low serum concentrations of this vitamin were associated, mainly, with insulin resistance. Monitoring the nutritional status of vitamin D in individuals with obesity that present with MUHO phenotype may contribute to minimize the occurrence and aggravation of diseases associated with obesity.

Associations Between Homeostasis Model Assessment (HOMA) and Routinely Examined Parameters in Individuals With Metabolic Syndrome

The aim of the study was to investigate whether routine clinical parameters, including visceral adiposity index (VAI) and atherogenic index of plasma (AIP), could become widely applicable predictors of insulin resistance (IR), evaluated using homeostasis model assessment (HOMA-IR, HOMA-β), with regard to presence of metabolic syndrome (MS). The study comprised 188 individuals identified to meet the MS criteria during regular health examinations and an equal number of age, sex-matched controls without MS. The strongest correlations were noted between HOMA-IR and waist circumference (WC) in the MS group (r=0.57) as well as between HOMA-IR and alanine aminotransferase (ALT, r=0.57) or aspartate aminotransferase (r=0.56) in the controls, with a statistical significance of p<0.001. In a multivariate linear regression model, the predictors of HOMA-IR were WC (linear coefficient β=0.1, p<0.001), ALT (β=2.28, p<0.001) and systolic blood pressure (β=0.04, p<0.001). HOMA-β was determined by WC (β=1.97, p=0.032) and ALT (β=99.49, p=0.004) and inversely associated with age (β=-1.31, p=0.004). Neither VAI nor AIP were significant predictors. The presence of MS was significantly associated with both HOMA-IR and HOMA-β. These results indicate that WC and ALT appear to be reliable predictors of IR. Comprehensive assessment of these parameters may serve for estimating the level of IR.

Dietary Patterns, Exercise, and the Metabolic Syndrome Among Young People in Urban Pakistan (Lahore)

Background: Increasing urbanization, mechanization, and rural-to-urban migration has led to deranged sleeping patterns, surplus energy intake, and sedentary lifestyles in South Asian young people. This shift poses an insidious health risk for the development of metabolic syndrome (MetS). Early detection is needed because in the South Asian population, this syndrome carries an increased risk of comorbidities compared to people without the syndrome. This study was designed to elucidate the prevalence of MetS and its risk factors in young people in urban areas of Pakistan. Methods: A cross-sectional study was conducted in four undergraduate institutions in Lahore, Pakistan. Five hundred and nine young people participated, and each provided their informed consent for the collection of data on their demographic, physical, and biochemical characteristics along with information on their dietary, sleep, and physical activity habits. Results: Most participants reported consuming greater-than-recommended amounts of protein and smaller-than-recommended amounts of vegetables and fruits. The International Diabetes Federation criteria for MetS were fulfilled by 6.1% of the students. Hypertension (67.7%) and hypo-HDL-emia (64.5%) were the most common risk factors. More than 50% of the respondents slept fewer hours per day than recommended, and 33% had a sedentary lifestyle. Men, participants with a family history of metabolic illness and those with low physical activity levels had higher odds of a positive result on screening for MetS. Conclusions: The early detection of MetS and early identification of probable risk factors may make beneficial contributions to both public health and clinical interventions directed at high-risk individuals. Establishing and using cutoff values for modified waist circumference and specific body mass index in Asian populations may aid in early detection.

Carbohydrate and sodium intake and physical activity interact with genetic risk scores of four genetic variants mainly related to lipid metabolism to modulate metabolic syndrome risk in Korean middle-aged adults

Metabolic syndrome (MetS) risk is influenced by genetic and environmental factors. The present study explored genetic risk scores (GRS) of genetic variants that influence the MetS and the effect of interactions between GRS and nutrient intake on MetS risk. The genetic variants that influence MetS risk were selected by genome-wide association study after adjusting for age, sex, area of residence and BMI in 8840 middle-aged adults. GRS were calculated by summing the risk alleles of the selected SNP and divided into low (0-1), medium (2-3) and high (4-7) risk groups, and the relationships between the MetS and GRS were determined by logistic regression after adjusting covariates involved in MetS risk. We also analysed the interaction between GRS and lifestyles. Four genetic variants (APOA5_rs651821, EFCAB4B_rs4766165, ZNF259_rs2160669 and APOBEC1_rs10845640) were selected because they increased MetS risk after adjusting for covariates. Individuals with medium-GRS and high-GRS alleles had a higher MetS risk by 1·48- and 2·23-fold, respectively, compared with those with low-GRS after adjusting for covariates. The increase in MetS risk was mainly related to serum TAG and HDL-cholesterol concentrations. The GRS had an interaction with carbohydrate (CHO) and Na intakes and daily physical activities for MetS risk. In conclusion, Asian middle-aged adults with high-GRS alleles were at increased MetS risk mainly due to dyslipidaemia. High daily physical activity (≥1 h moderate activity per d) reduced the MetS risk but a low-CHO diet (<65 % of total energy intake) increased the risk in carriers with high-GRS alleles. Low Na intake (<1·6 g Na intake/4 MJ) did not decrease its risk.

High- and low- selenium diets affect endocrine energy balance during early programming

High- and low- Se diets received by dams during gestation and lactation are related to insulin resistance in their pups. High-Se diet leads to an increase in serum insulin levels, which does not function properly, and an anabolic process. Low-Se diet is related to very low insulin values and an extreme catabolic energy imbalance. Selenoproteins have been implicated directly in the general endocrine regulation of appetite and energy homeostasis. To obtain information concerning how Se intake by dams is involved in regulating endocrine energy balance in progeny, three experimental groups of dam rats were used: control (Se: 0.1 ppm), Se-supplemented (Se: 0.5 ppm) and Se-deficient (Se: 0.01 ppm). At the end of lactation (21d old), the pups' appetite profile, Se levels, peptides from gastrointestinal tract (including pancreas), leptin, thyroid hormones, skeletal growth markers and cytokines in serum were measured. Low-Se diet leads to severe growth retardation, underdeveloped glands, a non-functional pancreas, non-operative high serum leptin levels and low GIT-anorexigenic signals. High-Se diet leads to non-operative high insulin secretion, obesity, inflammation and low leptin levels. These results point to Se as an important marker and a possible dietary supplementation treatment for gestating and lactating mothers in order to avoid metabolic disorders such as gestational diabetes or intrauterine growth retardation which could affect their progeny's future health in adulthood.

Proteomic Analysis of Plasma Reveals Fat Mass Influences Cancer-Related Pathways in Healthy Humans Fed Controlled Diets Differing in Glycemic Load

Increased adiposity and diets high in glycemic load (GL) are associated with increased risk of many chronic diseases including cancer. Using plasma from 80 healthy individuals [40 men/40 women, 29 with DXA-derived low fat mass (FM) and 51 with high FM] in a randomized cross-over-controlled feeding trial and arrays populated with 3,504 antibodies, we measured plasma proteins collected at baseline and end of each of two 28-day controlled diets: a low GL diet high in whole grains, legumes, fruits, and vegetables (WG) and a high GL diet high in refined grains and added sugars (RG). Following univariate testing for proteins differing by diet, we evaluated pathway-level involvement. Among all 80 participants, 172 proteins were identified as differing between diets. Stratifying participants by high and low FM identified 221 and 266 proteins, respectively, as differing between diets (unadjusted P < 0.05). These candidate proteins were tested for overrepresentation in Reactome pathways, corresponding to 142 (of 291) pathways in the high-FM group and 72 (of 274) pathways in the low-FM group. We observed that the cancer-related pathways, DNA Repair, DNA Replication, and Cell Cycle, were overrepresented in the high-FM participants while pathways involved in post-translational protein modification were overrepresented in participants with either FM. Although high-GL diets are associated with increased risk of some cancers, our study further suggests that biology associated with consumption of GL diets is variable depending on an individual's adiposity and dietary recommendations related to cancer prevention be made with the additional consideration of an individual's FM.

Can Visceral Adiposity Index Serve as a Simple Tool for Identifying Individuals with Insulin Resistance in Daily Clinical Practice?

Background and objectives: The visceral adiposity index (VAI), estimating visceral adiposity dysfunction through a simple formula, could serve as a useful tool for identifying individuals at higher cardiometabolic risk. Its relationship with insulin resistance (IR), assessed using the homeostasis model assessment of IR (HOMA-IR), and metabolic syndrome (MetS) components remains unclear. The study aimed to investigate the association of VAI with both HOMA-IR and MetS. Materials and Methods: After undergoing anthropometric and biochemical studies, 783 individuals were divided into three groups according to a number of present MetS components. The VAI cut-offs signaling MetS and HOMA-IR were determined by maximizing the sum of the sensitivity and specificity. Correlation analysis was performed to explore the associations between VAI and other tested parameters. A logistic stepwise regression analysis was applied to identify statistically significant determinants of HOMA-IR. Given the variability of reference values, two thresholds of HOMA-IR were applied, namely 2.0 and 3.8. Results: VAI increased significantly between the groups with a rising number of MetS components. The VAI cut-off for MetS was 2.37, with a sensitivity of 0.86 and a specificity of 0.78. The same cut-off point identified subjects with HOMA-IR = 3.8, with a sensitivity of 0.79 and a specificity of 0.66. The VAI cut-off for HOMA-IR = 2.0 was 1.89, with a sensitivity of 0.74 and a specificity of 0.68. The strongest correlations of VAI were noted with HOMA-IR (r = 0.51) and insulin (r = 0.49), respectively, while the strongest correlation of HOMA-IR was with waist circumference (r = 0.54). Not one of the routine parameters was a significant predictor in the regression analysis. Conclusions: The obtained results show an existing association of VAI with HOMA-IR. The high sensitivity and specificity of the cut-offs may allow the application of VAI in common clinical practice.

Maternal metabolic syndrome and selenium: Endocrine energy balance during early programming

BACKGROUND

Maternal metabolic syndrome during gestation and lactation leads to several Se-status-related metabolic changes in offspring. MS leads to hepatomegaly, liver oxidation, resistance to insulin challenges and selenoptroteins expression upregulation, producing an energy imbalance in hepatocytes. As Se is necessary for correct heart function, Se deposits are depleted and selenoproteins expression downregulated in heart; this depletion being related to cardiovascular damage. Recently, selenoproteins have been directly implicated in the central endocrine regulation of appetite and energy homeostasis.

METHODS

To obtain information about how Se is involved in regulating endocrine peripheral energy balance during MS process, two experimental groups of dam rats were used: control (Se: 0.1 ppm) and MS (Fructose 65% and Se: 0.1 ppm). At the end of lactation (21d old), the pups' appetite profile, tissular Se deposits and peptides from gastrointestinal tract (including pancreas), leptin, skeletal growth markers and cytokines in serum were measured.

RESULTS

MS-exposed pups present changes in Se homeostasis, appetite profile and endocrine energy balance signals related to impaired insulin secretion and high leptin serum values. This profoundly affects the pups' growth profile since muscle and bones are in catabolic process and brown adipose tissue (BAT) mass decreases.

CONCLUSION

These results indicate that the pups are suffering a process similar to diabetes type 1 which appeared when dams received low Se dietary supply and they point to Se as an important marker and key treatment for these disorders during gestation and lactation that affect future adult health.

Six Weeks of Calorie Restriction Improves Body Composition and Lipid Profile in Obese and Overweight Former Athletes

OBJECTIVE

The aim of the study was to compare the impact of 6 weeks of reducing daily caloric intake by 20% of total daily energy expenditure (TDEE)-CRI vs. reducing daily caloric intake by 30% of TDEE-CRII on body mass reduction and insulin metabolism in former athletes.

METHODS

94 males aged 35.7 ± 5.3 years, height 180.5 ± 4.1 cm, and body mass 96.82 ± 6.2 kg were randomly assigned to the CRI (n = 49) or CRII (n = 45) group. Thirty-one participants (18 subjects from CRI and 13 from CRII) resigned from the study. The effects of both diets on the body composition variables (body mass-BM; body fat-BF; fat free mass-FFM; muscle mass-MM; total body water-TBW), lipid profile (total lipids-TL; total cholesterol-TCh; HDL cholesterol-HDL; LDL cholesterol-LDL; triglycerides-TG), and glucose control variables (glucose-GL, insulin-I, HOMA-IR, insulin-like growth factor-1-IGF-1, leptin and adiponectin) were measured.

RESULTS

After adhering to the CR I diet, significant differences were observed in FFM, MM and TG. After adhering to the CR II diet, significant differences were registered in tCh, TL and LDL. Both diets had a significant influence on leptin and adiponectin concentrations. Significant differences in FFM, MM, and tCh were observed between the CR I and CR II groups. At the end of the dietary intervention, significant differences in BF, FFM, MM and TBW were observed between the CR I and CR II groups.

CONCLUSION

The 6 weeks of CR II diet appeared to be more effective in reducing BF and lipid profile and proved to be especially suitable for subjects with high body fat content and an elevated level of lipoproteins and cholesterol. Both reductive diets were effective in improving the levels of leptin and adiponectin in obese former athletes.

Jicama (Pachyrhizus erosus) fiber prevents excessive blood glucose and body weight increase without affecting food intake in mice fed with high-sugar diet

OBJECTIVE

Jicama (Pachyrhizus erosus) fiber has been documented to exert an immunomodulatory effect both in vitro and in vivo. However, its beneficial effect against metabolic syndrome remains unknown. This study aimed to reveal whether the jicama fiber (JF) could prevent the development of diabetes and obesity caused by a high-sugar diet (HSD).

MATERIALS AND METHODS

The JF was isolated from its tuberous part and subsequently used as a supplemental diet for adult male Bagg and Albino (BALB)/c mice fed with a HSD. Four different diet paradigms including normal diet, HSD (30% sucrose), and HSD in combination with 10% and 25% of JF, respectively, were deployed continuously for 8 weeks. Furthermore, the blood glucose level, glucose tolerance, body weight, food and water consumption as well as epididymal white adipose tissue (WAT) and interscapular brown adipose tissue (BAT) mass were determined.

RESULTS

Our results revealed that supplementation of 25% JF could significantly prevent the blood glucose increase, excessive body weight gain, and glucose intolerance in mice fed with HSD. Moreover, 10% and 25% JF blunted the HSD-induced WAT mass gain but failed to counteract the depletion of BAT mass. Furthermore, the fiber supplementation elicited a minimum effect on rhythm and total food and water intake.

CONCLUSION

The JF could effectively sustain blood glucose homeostasis as well as improve body weight and WAT mass profile against the development of diabetes and obesity caused by HSD.

Cocoa Shell Aqueous Phenolic Extract Preserves Mitochondrial Function and Insulin Sensitivity by Attenuating Inflammation between Macrophages and Adipocytes In Vitro

SCOPE

The aim is to assess the action of an aqueous extract from cocoa shell (CAE) and its main phenolic compounds to prevent the loss of obesity-induced mitochondrial function and insulin sensitivity, targeting inflammation between macrophages-adipocytes in vitro.

METHODS AND RESULTS

CAE (31-500 µg mL^-1 ) inhibits 3T3-L1 adipocytes lipid accumulation and induces browning during differentiation. LPS-stimulated RAW264.7 macrophages show reduced inducible nitric oxide synthase and cyclooxygenase-2 expression and lowered pro-inflammatory cytokine production when treated with CAE and pure phenolics. Inflammatory crosstalk created by stimulating adipocytes with macrophage-conditioned media (CM) is arrested; CAE diminishes tumor necrosis factor-α (67%) and promotes adiponectin secretion (12.3-fold). Mitochondrial function, measured by reactive oxygen species production, mitochondrial content, and activity, is preserved in CM-treated adipocytes through up-regulating peroxisome proliferator-activated receptor gamma coactivator 1-α expression. Increases in insulin receptor (9-fold), phosphoinositide 3-kinase (3-fold), protein kinase B (4-fold) phosphorylation, and a decrease in insulin receptor substrate 1 serine phosphorylation induce increased glucose uptake (34%) and glucose transporter 4 translocation (14-fold) in CM-induced adipocytes.

CONCLUSION

CAE phenolics promote a beige phenotype in adipocytes. Macrophages-adipocytes inflammatory interaction is reduced preventing mitochondrial dysfunction and insulin resistance. For the first time, CAE shows a positive effect on adipogenesis and inflammation-related disorders.

Suppressive Role of Boron on Adipogenic Differentiation and Fat Deposition in Human Mesenchymal Stem Cells

Over the past years, adipose tissue has become an invaluable source of mesenchymal stem cells (MSCs) due to development of improved isolation methodologies. In a recent work, our group established a primary culture of human adipose-derived stem cells (hADSCs), which were characterized for their stem cell characteristics in detail and studied their myogenic differentiation potential in presence of boron. In the current study, we focused on the effects of a boron-containing compound, sodium pentaborate pentahydrate (NaB), on the adipogenic differentiation of hADSCs. Incorporation of boron in various chemical derivates has been a novel interest in drug-discovery attempts due to increasing number of reports on their anticancer, antibacterial, antiviral, and antifungal activities. In this report, a striking suppressive activity of boron on adipogenic differentiation of hADSCs is observed in a dose-dependent manner. Higher concentrations of NaB (20, 50, and 100 μg/mL (68, 170 and 340 μM)) resulted in a progressive decrease of lipid deposition, suppressed master regulators of adipogenesis transcriptional programming at the mRNA and protein levels, while having no evident cytotoxicity on the cells. The findings of this study are encouraging to undertake further investigations on potential beneficial effects boron in terms of its impact on normal and dysfunctional adipose biology. In that respect, these results pave the path to evaluate boron-based compounds in prevention and treatment of obesity which is a modern age pandemic that is predominant worldwide and found in strong association with comorbidities, including type 2 diabetes, hypertension, cardiovascular disease, cancers, and others."

Effect of fish oil supplementation and restricted feeding on body fat distribution and blood lipid profile in a rabbit model of castration-induced obesity

This study investigates the effect of fish oil supplementation and restricted feeding on body fat distribution and blood lipid profile in experimentally induced obesity in rabbits. The trial was carried out with 30 male rabbits, divided into 5 groups of 6 animals each (NC - non-castrated, non-treated, full-diet fed; C100 - castrated, non-treated, full-diet fed; FO100 - castrated, treated with fish oil, full-diet fed; C50 - castrated, non-treated, 50% restricted fed; FO50 - castrated, treated with fish oil, 50% restricted fed). At the end of the experiment, plasma lipids measurement and quantification of fat distribution was performed. The results of this study indicate that fish oil supplementation reduces obesity-associated abnormalities in lipid profile (high-density lipoprotein cholesterol to low-density lipoprotein cholesterol ratio and non-esterified fatty acids) and in body fat distribution in full-diet fed rabbits. Restricted feeding (C50) alone and the combination of restricted feeding and fish oil supplementation (FO50) in particular, has a detrimental effect on the lipid profile despite the marked reduction in intra-abdominal fat.

Omega 3 rich diet modulates energy metabolism via GPR120-Nrf2 crosstalk in a novel antioxidant mouse model

With obesity rates reaching epidemic proportions, more studies concentrated on reducing the risk and treating this epidemic are vital. Redox stress is an important metabolic regulator involved in the pathophysiology of cardiovascular disease, Type 2 diabetes, and obesity. Oxygen and nitrogen-derived free radicals alter glucose and lipid homeostasis in key metabolic tissues, leading to increases in risk of developing metabolic syndrome. Oxidants derived from dietary fat differ in their metabolic regulation, with numerous studies showing benefits from a high omega 3 rich diet compared to the frequently consumed "western diet" rich in saturated fat. Omega 3 (OM3) fatty acids improve lipid profile, lower inflammation, and ameliorate insulin resistance, possibly through maintaining redox homeostasis. This study is based on the hypothesis that altering endogenous antioxidant production and/or increasing OM3 rich diet consumption will improve energy metabolism and maintain insulin sensitivity. We tested the comparative metabolic effects of a diet rich in saturated fat (HFD) and an omega 3-enriched diet (OM3) in the newly developed 'stress-less' mice model that overexpresses the endogenous antioxidant catalase. Eight weeks of dietary intervention showed that mice overexpressing endogenous catalase compared to their wild-type controls when fed an OM3 enriched diet, in contrast to HFD, activated GPR120-Nrf2 cross-talk to maintain balanced energy metabolism, normal circadian rhythm, and insulin sensitivity. These findings suggest that redox regulation of GPR120/FFAR4 might be an important target in reducing risk of metabolic syndrome and associated diseases.

Exercise as 'precision medicine' for insulin resistance and its progression to type 2 diabetes: a research review

Type 2 diabetes and obesity epidemics are in effect in the United States and the two pathologies are linked. In accordance with the growing appreciation that ‘exercise is medicine,’ it is intuitive to suggest that exercise can play an important role in the prevention and/or treatment of these conditions. However, if exercise is to truly be considered as a viable alternative to conventional healthcare prevention/treatment strategies involving pharmaceuticals, it must be prescribed with similar scrutiny. Indeed, it seems reasonable to posit that the recent initiative calling for ‘precision medicine’ in the US standard healthcare system should also be applied in the exercise setting. In this narrative review, we consider a number of explanations that have been forwarded regarding the pathological progression to type 2 diabetes both with and without the concurrent influence of overweight/obesity. Our goal is to provide insight regarding exercise strategies that might be useful as ‘precision medicine’ to prevent/treat this disease. Although the etiology of type 2 diabetes is complex and cause/consequence characteristics of associated dysfunctions have been debated, it is well established that impaired insulin action plays a critical early role. Consequently, an exercise strategy to prevent/treat this disease should be geared toward improving insulin sensitivity both from an acute and chronic standpoint. However, research suggests that a chronic improvement in insulin sensitivity only manifests when weight loss accompanies an exercise intervention. This has resonance because ectopic fat accumulation appears to represent a central component of disease progression regardless of whether obesity is also part of the equation. The cause/consequence characteristics of the relationship between insulin resistance, pathological fat deposition and/or mobilsation, elevated and/or poorly-distributed lipid within myocytes and an impaired capacity to use lipid as fuel remains to be clarified as does the role of muscle mitochondria in the metabolic decline. Until these issues are resolved, a multidimensional exercise strategy (e.g., aerobic exercise at a range of intensities and resistance training for muscular hypertrophy) could provide the best alternative for prevention/treatment.

Therapeutic and preventive effects of exercise on cardiometabolic parameters in aging and obese rats

BACKGROUND AND AIMS

Aging, obesity and sedentarism are among the most important predictors of cardiometabolic diseases. Aiming to reduce the impact of the combination of these three factors, we tested the therapeutic and preventive effects of exercise in aging and obese rats on the following cardiometabolic disease risk parameters: body fat, blood pressure, blood lipids, and glycemic homeostasis.

METHODS

Eighteen male Wistar rats (initial age = 4 months, and final age = 14 months) were randomly distributed into three aging and obese groups: sedentary, therapeutic exercise and preventive exercise. Food and caloric intake, body adiposity, muscle mass, cardiovascular parameters, biochemical markers, glycemic homeostasis, and gene expression of insulin-dependent, insulin-independent and insulin resistance pathways in skeletal muscle were evaluated.

RESULTS

Therapeutic and preventive exercises were associated with higher food and caloric intake, and expression of TBC1D1 in the soleus muscle, as well as lower total cholesterol/HDL and LDL/HDL ratios, glucose levels at the end (90 min) of the glucose tolerance test and IKBKB expression in the gastrocnemius and soleus muscles. Only the preventive exercise improved the cardiovascular and body composition parameters, glucose tolerance, insulin resistance and insulin sensitivity, besides reducing total cholesterol, triglycerides, triglycerides/HDL ratio, plasmatic insulin and MAPK8 expression in soleus. The preventive exercise group also presented greater expression of INRS, IRS1, IRS2, PIK3CA, AKT1, and SLC2A4 in gastrocnemius and soleus, TBC1D1 in gastrocnemius, and AKT2 and PRKAA1 in soleus.

CONCLUSIONS

Therapeutic exercise promoted some improvements on cardiometabolic parameters in aging and obese rats, however, the best benefits were achieved through the preventive exercise.

Autophagy as an emerging target in cardiorenal metabolic disease: From pathophysiology to management

Although advances in medical technology and health care have improved the early diagnosis and management for cardiorenal metabolic disorders, the prevalence of obesity, insulin resistance, diabetes, hypertension, dyslipidemia, and kidney disease remains high. Findings from numerous population-based studies, clinical trials, and experimental evidence have consolidated a number of theories for the pathogenesis of cardiorenal metabolic anomalies including resistance to the metabolic action of insulin, abnormal glucose and lipid metabolism, oxidative and nitrosative stress, endoplasmic reticulum (ER) stress, apoptosis, mitochondrial damage, and inflammation. Accumulating evidence has recently suggested a pivotal role for proteotoxicity, the unfavorable effects of poor protein quality control, in the pathophysiology of metabolic dysregulation and related cardiovascular complications. The ubiquitin-proteasome system (UPS) and autophagy-lysosomal pathways, two major although distinct cellular clearance machineries, govern protein quality control by degradation and clearance of long-lived or damaged proteins and organelles. Ample evidence has depicted an important role for protein quality control, particularly autophagy, in the maintenance of metabolic homeostasis. To this end, autophagy offers promising targets for novel strategies to prevent and treat cardiorenal metabolic diseases. Targeting autophagy using pharmacological or natural agents exhibits exciting new strategies for the growing problem of cardiorenal metabolic disorders.

Effect of octreotide on pancreatic fibrosis in rats with high-fat diet-induced obesity

BACKGROUND/AIMS

To explore the effect of octreotide on pancreatic fibrosis induced by high-fat diet (HFD) and its mechanism of action.

METHODS

Sprague-Dawley (SD) rats were assigned to control, HFD, or octreotide treatment groups. Glucose and insulin tolerance tests (GTT and ITT), fasting plasma glucose (FPG), and fasting insulin (FINS), serum and pancreatic lipid levels, were measured, and the Lee's index and the homeostatic model assessment (HOMA) index were calculated. The expression levels of alpha-smooth muscle actin (α-SMA), desmin, connective tissue growth factor (CTGF), transforming growth factor beta1 (TGF-β1), Smad3, and Smad7 in the pancreas were quantified. The LTC-14 cell line, which has features of primary rat pancreatic stellate cells (PSCs), was used for in vitro studies.

RESULTS

The AUC of ipGTT and ipITT, and FPG, FINS, lipid levels, were elevated after HFD feeding; however, they decreased after octreotide administration. The expression of α-SMA, CTGF, TGF-β1, and Smad3 in the HFD group were increased relative to the control group, but Smad7 expression was decreased. After treatment with octreotide, α-SMA, CTGF, TGF-β1, and Smad3 expression decreased, whereas the expression of Smad7 increased. In vitro studies showed that the expression of CTGF, TGF-β1, and Smad3 increased with palmitate treatment (PA), which mimics HFD treatment; and octreotide treatment decreased the expression of these proteins. The α-SMA and Smad7 expression levels remained unchanged among the three groups.

CONCLUSIONS

Octreotide can ameliorate pancreatic fibrosis and improve pancreatic beta-cell function induced in HFD treated rats, possibly by inhibiting PSC activation and by decreasing pancreatic extracellular matrix (ECM) through the TGF-β1/Smad signaling pathway.

High-fat diet-induced hypertension is associated with a proinflammatory T cell profile in male and female Dahl salt-sensitive rats

Evidence supports a sex difference in the impact of a high-fat diet (HFD) on cardiovascular outcomes, with male experimental animals exhibiting greater increases in blood pressure (BP) than female experimental animals. The immune system has been implicated in HFD-induced increases in BP, and there is a sex difference in T-cell activation in hypertension. The goal of this study was to determine the impact of HFD on BP and aortic and renal T cell profiles in male and female Dahl salt-sensitive (DSS) rats. We hypothesized that male DSS rats would have greater increases in BP and T cell infiltration in response to a HFD compared with female DSS rats. BP was measured by tail-cuff plethysmography, and aortic and renal T cells were assessed by flow cytometric analysis in male and female DSS rats on a normal-fat diet (NFD) or HFD from 12 to 16 wk of age. Four weeks of HFD increased BP in male and female DSS rats to a similar degree. Increases in BP were accompanied by increased percentages of CD4⁺ T cells and T helper (Th)17 cells in both sexes, although male rats had more proinflammatory T cells. Percentages of renal CD3⁺ and CD4⁺ T cells as well as Th17 cells were increased in both sexes by the HFD, although the increase in CD3⁺ T cells was greater in male rats. HFD also decreased the percentage of aortic and renal regulatory T cells in both sexes, although female rats maintained more regulatory T cells than male rats regardless of diet. In conclusion, both male and female DSS rats exhibit BP sensitivity to a HFD; however, the mechanisms mediating HFD-induced increases in BP may be distinct as male rats exhibit greater increases in the percentage of proinflammatory T cells than female rats.

NEW & NOTEWORTHY Our study demonstrates that male and female Dahl salt-sensitive rats exhibit similar increases in blood pressure to a high-fat diet and an increase in aortic and renal T cells. These results are in contrast to studies showing that female rats remain normotensive and/or upregulate regulatory T cells in response to hypertensive stimuli compared with male rats. Our data suggest that a 4-wk high-fat diet has sex-specific effects on the T cell profile in Dahl salt-sensitive rats.

Gestational diabetes mellitus: Multi-disciplinary treatment approaches

Gestational diabetes mellitus (GDM) is the most common metabolic disease of pregnancy, associated with several perinatal complications. Adequate glycemic control has been proved to decrease risk of GDM-related complications. Several studies have shown the beneficial effect of exercise and medical nutrition treatment on glycemic and weight control in GDM-affected women. Moreover, pharmacological agents, such as insulin and specific oral anti-diabetic agents can be prescribed safely during pregnancy, decreasing maternal blood glucose and, thus, perinatal adverse outcomes. Multi-disciplinary treatment approaches that include both lifestyle modifications (medical nutritional therapy and daily physical exercise) and pharmacological treatment, in cases of failure of the former, constitute the most effective approach. Insulin is the gold standard pharmacological agent for GDM treatment. Metformin and glyburide are two oral anti-diabetic agents that could serve as alternative, although not equal in terms of effectiveness and safety, treatment for GDM. As studies on short-term safety of metformin are reassuring, in some countries it is considered as first-line treatment for GDM management. More studies are needed to investigate the long-term effects on offspring. As safety issues have been raised on the use of glyburide during pregnancy, it must be used only when benefits surpass possible risks.

Development of Low Glycemic Index Foods and Their Glucose Response in Young Healthy Non-Diabetic Subjects

Development of low glycemic-foods is important in the prevention and management of type 2 diabetes. In this context, we prepared four test foods (TFs) (two mixed mini-meals and two breakfast items) with low glycemic-components and assessed their glycemic index (GI) in young healthy non-diabetic volunteers with mean age of 29 yr, body mass index of 24 kg/m2, and fasting plasma glucose levels less than 4.62 mmol/L. Volunteers were given 50 g of glucose, as a reference food (RF) on the first day, and TFs, i.e. TF1 (mixed mini meal: roti made of wheat flour and chana dal+ curd), TF2 [mixed mini meal made of wheat, pearl barley, and Bengal gram flour (besan) mix with chana whole (unhusked chana+curd)], TF3 (pearl barley rawa upma), and TF4 (wheat rawa upma) were given 2-day intervals in the same order. Glucose levels at fasting conditions and after the consumption of RF and TFs at different time intervals (15, 30, 45, 60, 90, and 120 min) were measured, and the incremental area under curve (IAUC) for glucose and GI of the TFs were calculated. The glucose IAUC values at different time points were highest for TF2 (GI=71.9±7.4), while all other TFs had comparable GI in the range of 53.7~54.9. Among the various TFs, TF1, TF3, and TF4 exerted low to moderate glycemic response, and thus can be classified as low glycemic-foods. Nevertheless, these foods need to be tested for their efficacy in controlling and/or managing hyperglycemia and glucose over-load in diabetic subjects.

Functionalized gold and persistent luminescence nanoparticle-based ratiometric absorption and TR-FRET nanoplatform for high-throughput sequential detection of l-cysteine and insulin

In vitro diagnostic is a crucial component of healthcare systems for early diagnosis of diseases and follow-up therapy, which generally makes clinical diagnosis faster, easier, and painless for patients. Herein, we report a dual-signaling nanoplatform for ratiometric absorption and time-resolved fluorescence resonance energy transfer based on l-cysteine-mediated aggregated gold nanoparticles and long afterglow nature of persistent luminescence nanoparticles. With this nanoplatform, we have achieved high-throughput sequential detection of l-cysteine and insulin in human serum without matrix interference. The proposed nanoplatform shows excellent linearity and precision for the determination of l-cysteine in the range of 10 nM to 5.5 μM with the limit of detection (LOD) of 2.2 nM and for the detection of insulin in the range of 12 pM to 3.44 nM with LOD of 2.06 pM. The developed dual-signaling nanoplatform has been successfully applied for the sequential determination of l-cysteine and insulin in human serum.

Tpcn2 knockout mice have improved insulin sensitivity and are protected against high-fat diet-induced weight gain

Type 2 diabetes is a complex disorder affected by multiple genes and the environment. Our laboratory has shown that in response to a glucose challenge, two-pore channel 2 ( Tpcn2) knockout mice exhibit a decreased insulin response but normal glucose clearance, suggesting they have improved insulin sensitivity compared with wild-type mice. We tested the hypothesis that improved insulin sensitivity in Tpcn2 knockout mice would protect against the negative effects of a high fat diet. Male and female Tpcn2 knockout (KO), heterozygous (Het), and wild-type (WT) mice were fed a low-fat (LF) or high-fat (HF) diet for 24 wk. HF diet significantly increases body weight in WT mice relative to those on the LF diet; this HF diet-induced increase in body weight is blunted in the Het and KO mice. Despite the protection against diet-induced weight gain, however, Tpcn2 KO mice are not protected against HF-diet-induced changes in glucose or insulin area under the curve during glucose tolerance tests in female mice, while HF diet has no significant effect on glucose tolerance in the male mice, regardless of genotype. Glucose disappearance during an insulin tolerance test is augmented in male KO mice, consistent with our previous findings suggesting enhanced insulin sensitivity in these mice. Male KO mice exhibit increased fasting plasma total cholesterol and triglyceride concentrations relative to WT mice on the LF diet, but this difference disappears in HF diet-fed mice where there is increased cholesterol and triglycerides across all genotypes. These data demonstrate that knockout of Tpcn2 may increase insulin action in male, but not female, mice. In addition, both male and female KO mice are protected against diet-induced weight gain, but this protection is likely independent from glucose tolerance, insulin sensitivity, and plasma lipid levels.

Metabolic Flexibility as an Adaptation to Energy Resources and Requirements in Health and Disease

The ability to efficiently adapt metabolism by substrate sensing, trafficking, storage, and utilization, dependent on availability and requirement, is known as metabolic flexibility. In this review, we discuss the breadth and depth of metabolic flexibility and its impact on health and disease. Metabolic flexibility is essential to maintain energy homeostasis in times of either caloric excess or caloric restriction, and in times of either low or high energy demand, such as during exercise. The liver, adipose tissue, and muscle govern systemic metabolic flexibility and manage nutrient sensing, uptake, transport, storage, and expenditure by communication via endocrine cues. At a molecular level, metabolic flexibility relies on the configuration of metabolic pathways, which are regulated by key metabolic enzymes and transcription factors, many of which interact closely with the mitochondria. Disrupted metabolic flexibility, or metabolic inflexibility, however, is associated with many pathological conditions including metabolic syndrome, type 2 diabetes mellitus, and cancer. Multiple factors such as dietary composition and feeding frequency, exercise training, and use of pharmacological compounds, influence metabolic flexibility and will be discussed here. Last, we outline important advances in metabolic flexibility research and discuss medical horizons and translational aspects.

Source and amount of carbohydrate in the diet and inflammation in women with polycystic ovary syndrome

High carbohydrate intake and low-grade inflammation cooperate with insulin resistance and hyperandrogenism to constitute an interactive continuum acting on the pathophysiology of polycystic ovary syndrome (PCOS), the most common endocrine disorder in women of reproductive age characterised by oligo-anovulatory infertility and cardiometabolic disorders. The role of insulin in PCOS is pivotal both in regulating the activity of ovarian and liver enzymes, respectively involved in androgen production and in triggering low-grade inflammation usually reported to be associated with an insulin resistance, dyslipidaemia and cardiometabolic diseases. Although an acute hyperglycaemia induced by oral glucose loading may increase inflammation and oxidative stress by generating reactive oxygen species through different mechanisms, the postprandial glucose increment, commonly associated with the Western diet, represents the major contributor of chronic sustained hyperglycaemia and pro-inflammatory state. Together with hyperinsulinaemia, hyperandrogenism and low-grade inflammation, unhealthy diet should be viewed as a key component of the 'deadly quartet' of metabolic risk factors associated with PCOS pathophysiology. The identification of a tight diet-inflammation-health association makes the adoption of healthy nutritional approaches a primary preventive and therapeutic tool in women with PCOS, weakening insulin resistance and eventually promoting improvements of reproductive life and endocrine outcomes. The intriguing nutritional-endocrine connections operating in PCOS underline the role of expert nutritionists in the management of this syndrome. The aim of the present review is to provide an at-a-glance overview of the possible bi-directional mechanisms linking inflammation, androgen excess and carbohydrate intake in women with PCOS.

Adipocytes spectrum - From homeostasia to obesity and its associated pathology

Firstly identified by anatomists, the fat tissue is nowadays an area of intense research due to increased global prevalence of obesity and its associated diseases. Histologically, there are four types of fat tissue cells which are currently recognized (white, brown, beige, and perivascular adipocytes). Therefore, in this study we are reviewing the most recent data regarding the origin, structure, and molecular mechanisms involved in the development of adipocytes. White adipocytes can store triglycerides as a consequence of lipogenesis, under the regulation of growth hormone or leptin and adiponectin, and release fatty acids resulted from lipolysis, under the regulation of the sympathetic nervous system, glucocorticoids, TNF-α, insulin, and natriuretic peptides. Brown adipocytes possess a mitochondrial transmembrane protein thermogenin or UCP1 which allows heat generation. Recently, thermogenic, UCP positive adipocytes have been identified in the subcutaneous white adipose tissue and have been named beige adipocytes. The nature of these cells is still controversial, as current theories are suggesting their origin either by transdifferentiation of white adipocytes, or by differentiation from an own precursor cell. Perivascular adipocytes surround most of the arteries, exhibiting a supportive role and being involved in the maintenance of intravascular temperature. Thoracic perivascular adipocytes resemble brown adipocytes, while abdominal ones are more similar to white adipocytes and, consequently, are involved in obesity-induced inflammatory reactions. The factors involved in the regulation of adipose stem cells differentiation may represent potential pathways to inhibit or to divert adipogenesis. Several molecules, such as pro-adipogenic factors (FGF21, BMP7, BMP8b, and Cox-2), cell surface proteins or receptors (Asc-1, PAT2, P2RX5), and hypothalamic receptors (MC4R) have been identified as the most promising targets for the development of future therapies. Further investigations are necessary to complete the knowledge about adipose tissue and the development of a new generation of therapeutic tools based on molecular targets.

Irisin Serum Levels in Metabolic Syndrome Patients Treated with Three Different Diets: A Post-Hoc Analysis from a Randomized Controlled Clinical Trial

BACKGROUND

Irisin, a hormone-like myokine, regulates energy homeostasis and mediates the benefits of physical activity on health.

METHODS

To estimate the effect of different diets on irisin concentrations in subjects with the Metabolic Syndrome (MetS).

METHODS

Subjects with MetS were derived from a population survey; 163 subjects were enrolled and randomized to a: Low Glycaemic Index (LGID), Mediterranean (MD) or Low Glycaemic Index Mediterranean (LGIMD) Diet, and the groups were compared, also with 80 controls without MetS. Sociodemographic, medical and nutritional data were collected and fasting blood samples drawn. Subjects underwent LUS and bioimpedentiometry. Generalized Estimating Equations were performed.

RESULTS

At baseline, lower irisin concentrations were observed in MetS subjects. Mean irisin levels increased in all diet groups but only the LGID group reached statistical significance, as well as showing an interaction between LGID and time at the sixth month examination (4.57, 95% CI −1.27, 7.87). There was a positive effect of Vegetable Proteins (0.03, 95% CI −0.01,0.06) and Saturated Fatty Acids (0.04, 95% CI 0.01, 0.07) on irisin concentrations. In the LGIMD, a positive effect on Fat-Free Mass (0.38, 95% CI 0.19, 0.57) and a negative effect on the Body Mass Index (−0.75, 95% CI −1.30, −0.19) were observed.

CONCLUSIONS

There seems to be a link between diet and muscle physiology. We showed that patients following a LGID had higher levels of irisin, a promising biomarker of muscle activity.

Prevalence and risk factors for prehypertension and hypertension among adults in Central China from 2000-2011

BACKGROUND

Hypertension is frequently studied in surveys; however, prehypertension, a new blood pressure status between normotension and hypertension, is rarely reported.

METHODS

All data were derived from the China Health and Nutrition Survey (CHNS) and were analysed by logistic regression for correlation.

RESULTS

The prehypertension prevalence was 27.4%, with a hypertension rate of 36.9%. The awareness, treatment, and uncontrolled rates among all hypertension participates were 19.8%, 83.6%, and 55.0%, respectively. The epidemic rate of hypertension increased with increasing age (p < 0.001), and prehypertension appeared to have an epidemic peak in the age group of 38-57 years (p < 0.001). In general, the incidence of hypertension in urban participants was higher than in rural subjects (p < 0.001), and prehypertension in urban subjects was lower than that in rural subjects (p < 0.001). According to the results of logistic regression, hypertension and prehypertension were associated with age, gender, location, body mass index (BMI), body fat rate (BFR), waist circumference (WC), education, and the intake of energy-yielding nutrients<0.05).

CONCLUSION

The current study reveals a high epidemic rate of hypertension and prehypertension in Central China. These results indicate the urgent need to develop strategies to improve the prevention of hypertension and prehypertension in Central China.

Protective effects of Chinese Fenggang zinc selenium tea on metabolic syndrome in high-sucrose-high-fat diet-induced obese rats

The protective effect of zinc selenium tea against metabolic syndrome (MetS) was tested by using a high-sucrose-high-fat diet (HSHFD)-induced MetS model. Fifty Sprague–Dawley rats were randomly divided into five groups: normal diet (C-group), HSHFD (CH-group), HSHFD + green tea (0.24 g/kg/day) (TH-group), HSHFD + low-dose zinc selenium organic tea (0.24 g/kg/day) (ZTHL-group), and HSHFD + high-dose zinc selenium organic tea (1.20 g/kg/day) (ZTHH-group). After 8 weeks, compared to both the C-group and CH-group, the hepatosomatic index (HI) was significantly reduced in the ZTHL-group (p < 0.05). Fasting blood glucose (FBG) levels were highest in the TH-group, followed by the CH-group, then the ZTHL-group, then the ZTHH-group, and finally the C-group. Compared with the CH-group, the serum total cholesterol (TC) and low density lipid-cholesterol (LDL-C) concentrations were significantly lower in the ZTHH-group (p < 0.05). Significant decreases in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bile acids (TBA), alkaline phosphatase (ALP), and direct bilirubin (DBIL) levels were observed in ZTHL-group versus the CH-group (p < 0.05). Serum alpha-L-fucosidase (AFU) levels in the ZTHH-group were lower than in the CH-group (P < 0.01). Histopathological examination of the liver and fat biopsies illustrates that the liver cells showed a decrease in the extent of necrosis and dropsy in the ZTHL-group and ZTHH-group versus the CH-group. Zinc selenium tea showed a protection effect against hepatic damage.

The impact of parental history of type 2 diabetes on hyperinsulinemia and insulin resistance in subjects from central Mexico

AIMS

Hyperinsulinemia and insulin resistance are both associated with the development of Type 2 Diabetes and other pathologies; however, the influence of parental history of Type 2 diabetes (PH-T2D) has yet to be investigated. Therefore, this study was conducted to determine the effect of PH-T2D has on the risk of developing hyperinsulinemia and IR.

MATERIALS AND METHODS

1092 subjects (703 non-pregnant females and 389 males) were enrolled for a cross-sectional study. Clinical and biochemical parameters were collected. Subjects were allocated according to their PH-T2D: no parents, one parent, or both parents. Insulin resistance was calculated using the HOMA1 equation (HOMA1-IR). Logistic regression was used to determine the association (odds ratio) between PH-T2D and hyperinsulinemia or insulin resistance.

RESULTS

Increasing degrees of PH-T2D were associated with significant increases in fasting plasma glucose, insulin, and HOMA1-IR (p <0.05). Subjects having one or both parents were associated with an increase risk of developing hyperinsulinemia (odds ratio=1.53, 95%CI: 1.12-2.09, and odds ratio=1.92, 95%CI: 1.21-3.06, respectively) and insulin resistance (odds ratio=1.47, 95%CI: 1.08-2.00 and odds ratio=1.77, 95%CI: 1.09-2.87, respectively), when adjusting for age, sex, BMI, fasting plasma glucose, and triglycerides.

CONCLUSION

The presences of PH-T2D significantly increased the risk of developing hyperinsulinemia and insulin resistance.

The interrelation of osteoarthritis and diabetes mellitus: considering the potential role of interleukin-10 and in vitro models for further analysis

INTRODUCTION

Today, not only the existence of an interrelation between obesity/adipositas and osteoarthritis (OA) but also the association of OA and diabetes mellitus (DM) are widely recognized. Nevertheless, shared influence factors facilitating OA development in DM patients still remain speculative up until now. To supplement the analysis of clinical data, appropriate in vitro models could help to identify shared pathogenetic pathways. Informative in vitro studies could later be complemented by in vivo data obtained from suitable animal models.

MATERIALS AND METHODS

Therefore, this detailed review of available literature was undertaken to discuss and compare the results of currently published in vitro studies focusing on the interrelation between OA, the metabolic syndrome and DM and to propose models to further study the molecular pathways.

RESULTS

The survey of literature presented here supports the hypothesis that the pathogenesis of OA in DM is based on imbalanced molecular pathways with a putative crucial role of antiinflammatory cytokines such as IL-10.

CONCLUSION

Future development of versatile micro-scaled in vitro models such as combining DM and OA on chip could allow the identification of common pathogenetic pathways and might help to develop novel therapeutic strategies.

Circulating IL-8 levels are increased in patients with type 2 diabetes and associated with worse inflammatory and cardiometabolic profile

AIMS

Interleukin-8 (IL-8) is a chemokine involved in systemic immunity, macrophages infiltration and activation in adipose tissue and may play a significant role in the pathogenesis of type 2 diabetes (T2D) and atherosclerosis. Aims of this study were to evaluate circulating IL-8 levels in adult patients with T2D in comparison with non-diabetic subjects and to describe clinical and biochemical correlates of IL-8 concentration.

METHODS

For this cross-sectional study, we enrolled 79 consecutive T2D individuals referring to our diabetes outpatient clinics at Sapienza University of Rome, and 37 sex, age and BMI comparable non-diabetic subjects as a control group. Clinical parameters and medical history were recorded; fasting blood sampling was performed for biochemistry and for measuring serum IL-8, IL-6, TNF-α, CRP, adiponectin and 25(OH)vitamin D [25(OH)D] levels.

RESULTS

Patients with T2D exhibited significantly higher serum IL-8 levels than non-diabetic subjects (69.27 ± 112.83 vs. 16.03 ± 24.27 pg/mL, p < 0.001). In diabetic patients, increased IL-8 concentration correlated with higher IL-6 (p < 0.001), TNF-α (p = 0.02), FBG (p = 0.035), HbA1c (p = 0.04) and LDL-C (p = 0.04) and with lower adiponectin (p = 0.02) and 25(OH)D (p = 0.003) concentrations.

CONCLUSIONS

Patients with T2D display a marked elevation of circulating IL-8 levels which identify subjects with worse inflammatory, glycometabolic and lipid profile and lower vitamin D levels. Further studies are warranted for evaluating a possible role of IL-8 as a novel marker for risk stratification in T2D patients.

Metabolic syndrome and inflammation in adipose tissue occur at different times in animals submitted to a high-sugar/fat diet

Obesity is associated with low-grade inflammation, triggered in adipose tissue, which may occur due to an excess of SFA from the diet that can be recognised by Toll-like receptor-4. This condition is involved in the development of components of the metabolic syndrome associated with obesity, especially insulin resistance. The aim of the study was to evaluate the manifestation of the metabolic syndrome and adipose tissue inflammation as a function of the period of time in which rats were submitted to a high-sugar/fat diet (HSF). Male Wistar rats were divided into six groups to receive the control diet (C) or the HSF for 6, 12 or 24 weeks. HSF increased the adiposity index in all HSF groups compared with the C group. HSF was associated with higher plasma TAG, glucose, insulin and leptin levels. Homeostasis model assessment increased in HSF compared with C rats at 24 weeks. Both TNF-α and IL-6 were elevated in the epididymal adipose tissue of HSF rats at 24 weeks compared with HSF at 6 weeks and C at 24 weeks. Only the HSF group at 24 weeks showed increased expression of both Toll-like receptor-4 and NF-κB. More inflammatory cells were found in the HSF group at 24 weeks. We can conclude that the metabolic syndrome occurs independently of the inflammatory response in adipose tissue and that inflammation is associated with hypertrophy of adipocytes, which varies according to duration of exposure to the HSF.

Interpreting lipoproteins in nonalcoholic fatty liver disease

PURPOSE OF REVIEW

The pathophysiologies of nonalcoholic fatty liver disease (NAFLD), metabolic syndrome, and cardiovascular disease are closely interlinked and associated with atherogenic dyslipidemia. Liver and cardiovascular disease may silently progress to advanced stages if alarming signs, such as abdominal obesity, elevated fasting and postprandial triglycerides, and low HDL cholesterol are overlooked. We review the metabolic mechanisms in NAFLD at the cellular level in the context of standard clinical lipid measurements.

RECENT FINDINGS

We discuss the pathogenesis of NAFLD, nonalcoholic steatohepatitis (NASH), and metabolic syndrome, atherogenic dyslipidemia, lipotoxicity, and lipophagy.

SUMMARY

Physicians should infer from biomarkers or clinical findings that their abdominally obese patients are at risk of severe cardiovascular, liver fatty disease, or both. Physicians should carry out laboratory tests of plasma cholesterol, triglycerides, LDL and HDL cholesterol, non-HDL cholesterol, apolipoprotein B and platelets, and for diabetes, but importantly, plasma triglycerides also in the nonfasting state. But note, clinical routine plasma lipid and lipoprotein measurements are not necessarily reliable for interpreting severe metabolic changes. Notably, in advanced stages of NAFLD (i.e., late steatohepatitis and cirrhosis), routine lipid profiles do not necessarily show any more abnormalities.