Characterization of the impaired glucose homeostasis produced in C57BL/6 mice by chronic exposure to arsenic and high-fat diet

Background: Type 2 diabetes is characterized by glucose intolerance and insulin resistance. Obesity is the leading cause of type 2 diabetes. Growing evidence suggests that chronic exposure to inorganic arsenic (iAs) also produces symptoms consistent with diabetes. Thus, iAs exposure may further increase the risk of diabetes in obese individuals.Objectives: Our goal was to characterize diabetogenic effects of iAs exposure and high-fat diet (HFD) in weaned C57BL/6 mice.Methods: Mice were fed HFD or low-fat diet (LFD) while exposed to iAs in drinking water (25 or 50 ppm As) for 20 weeks; control HFD and LFD mice drank deionized water. Body mass and adiposity were monitored throughout the study. We measured glucose and insulin levels in fasting blood and in blood collected during oral glucose tolerance tests (OGTT) to evaluate the diabetogenic effects of the treatment.Results: Control mice fed HFD accumulated more fat, had higher fasting blood glucose, and were more insulin resistant than were control LFD mice. However, these diabetes indicators decreased with iAs intake in a dose-dependent manner. OGTT showed impaired glucose tolerance for both control and iAs-treated HFD mice compared with respective LFD mice. Notably, glucose intolerance was more pronounced in HFD mice treated with iAs despite a significant decrease in adiposity, fasting blood glucose, and insulin resistance.Conclusions: Our data suggest that iAs exposure acts synergistically with HFD-induced obesity in producing glucose intolerance. However, mechanisms of the diabetogenic effects of iAs exposure may differ from the mechanisms associated with the obesity-induced type 2 diabetes.     

Long-term intake of rice improves insulin sensitivity in mice fed a high-fat diet

ObjectiveThe aim of this study was to evaluate the effects of rice as a carbohydrate source and its molecular mechanisms on insulin resistance induced by a high-fat diet (HFD).MethodsC57 BL/6 J mice were divided into three groups and were fed a low-fat diet (LFD); a HFD (with 18% fat, 0.5% cholesterol, 51.5% w/w cornstarch and sucrose); or a HFD with rice (HFD-CR, with 18% fat, 0.5% cholesterol and 51.5% w/w rice powder) for 12 wk. In the HFD-CR diet, cooked rice powder was substituted for cornstarch and sucrose in the HFD as a carbohydrate source.ResultsHFD-CR–fed mice had significantly lower body weight, blood glucose, insulin and leptin levels and ameliorated glucose responses with decreased homeostasis model assessment-insulin resistance compared with HFD-fed mice. Hepatic mRNA levels of phosphoenolpyruvate carboxykinase and glucose-6-phosphatase were down-regulated in the HFD-CR group. The hypertrophied islet size and the decreased pancreatic mRNA expression of glucose transporter 2 in the HFD group were normalized with cooked rice consumption. Rice promoted glucose uptake by activating AMP-activated protein kinase and downstream glucose transporter 4 in the skeletal muscle.ConclusionRice consumption as a carbohydrate source might potentiate improvements in glucose uptake via AMP-activated protein kinase activation and glucose transporter 4 expression in the skeletal muscles, thereby improving insulin sensitivity.     

Beneficial effect of dietary geranylgeraniol on glucose homeostasis and bone microstructure in obese mice is associated with suppression of proinflammation and modification of gut microbiome

Geranylgeraniol (GGOH) is found in edible oils such as olive, linseed, and sunflower oils, which have favorable metabolic effects. However, it is unknown whether these physiological benefits are mediated through the gut microbiome. Thus, the purpose of this study was to test the hypothesis that GGOH supplementation would improve glucose homeostasis and benefit the bone microstructure in obese mice through suppression of inflammation and modification of gut microbiota composition. Thirty-six male C57BL/6J mice were divided into 3 groups: a low-fat diet, a high-fat diet (HFD), and an HFD supplemented with 800 mg GGOH/kg diet (GG) for 14 weeks. Glucose and insulin tolerance tests were measured at baseline and end of study. The concentrations of adipokine cytokines (resistin, leptin, monocyte chemoattractant protein-1, interleukin-6) were measured via ELISA. Bone microarchitecture and quality were measured by micro-CT. Microbiome analysis was performed using 16S rRNA amplicon sequencing on cecal content. Relative to the HFD group, the GG group: (1) improved glucose tolerance and insulin sensitivity; (2) reduced production of pro-inflammatory adipokines, (3) increased serum procollagen I intact N-terminal propeptide (bone formation marker) concentrations, while decreasing serum collagen type 1 cross-linked C-telopeptide (bone resorption marker) levels, and (4) increased stiffness at both femur and LV-4 and cortical thickness at femoral midshaft. Compared to the HFD group, the GG group had an increased abundance of Butyricicoccus pullicaecorum and decreased Dorea longicatena in the cecal microbiome. Collectively, GGOH improves glucose homeostasis and bone microstructure in obese mice, probably via suppression of pro-inflammation and modification of microbiome composition.     

Protective Effect of Vanillic Acid against Hyperinsulinemia,Hyperglycemia and Hyperlipidemia via Alleviating Hepatic Insulin Resistance and Inflammation in High-Fat Diet (HFD)-Fed Rats

Excess free fatty acid accumulation from abnormal lipid metabolism results in the insulin resistance in peripheral cells, subsequently causing hyperinsulinemia, hyperglycemia and/or hyperlipidemia in diabetes mellitus (DM) patients. Herein, we investigated the effect of phenolic acids on glucose uptake in an insulin-resistant cell-culture model and on hepatic insulin resistance and inflammation in rats fed a high-fat diet (HFD). The results show that vanillic acid (VA) demonstrated the highest glucose uptake ability among all tested phenolic acids in insulin-resistant FL83B mouse hepatocytes. Furthermore, rats fed HFD for 16 weeks were orally administered with VA daily (30 mg/kg body weight) at weeks 13–16. The results show that levels of serum insulin, glucose, triglyceride, and free fatty acid were significantly decreased in VA-treated HFD rats (p < 0.05), indicating the protective effects of VA against hyperinsulinemia, hyperglycemia and hyperlipidemia in HFD rats. Moreover, VA significantly reduced values of area under the curve for glucose (AUC_glucose) in oral glucose tolerance test and homeostasis model assessment-insulin resistance (HOMA-IR) index, suggesting the improving effect on glucose tolerance and insulin resistance in HFD rats. The Western blot analysis revealed that VA significantly up-regulated expression of hepatic insulin-signaling and lipid metabolism-related protein, including insulin receptor, phosphatidylinositol-3 kinase, glucose transporter 2, and phosphorylated acetyl CoA carboxylase in HFD rats. VA also significantly down-regulated hepatic inflammation-related proteins, including cyclooxygenase-2 and monocyte chemoattractant protein-1 expressions in HFD rats. These results indicate that VA might ameliorate insulin resistance via improving hepatic insulin signaling and alleviating inflammation pathways in HFD rats. These findings also suggest the potential of VA in preventing the progression of DM.     

高脂日粮改变小鼠股骨基因表达谱的聚类分析

目的研究饲喂高脂日粮对小鼠股骨基因表达谱的影响。方法 4w龄C57BL/6雄性小鼠,体重13～14g,饲养正常日粮4d后,根据体重随机分为对照组(基础日粮)和高脂日粮组(19.5%猪油),每组8只小鼠,饲养12w后处死,迅速分离股骨,每组4份50mg股骨,提取RNA后等量合并,应用Affymetrix MOE430A小鼠基因表达芯片获得股骨基因表达谱变化的信息,通过DAVID在线分析工具进行聚类分析。结果长期饲喂高脂日粮导致C57BL/6小鼠股骨基因显著表达差异主要涉及如下功能:阳离子通道、信号转导和转入调控、骨矿化、磷代谢调控和胶原合成。结论长期摄入高脂日粮导致小鼠骨组织众多骨代谢相关基因表达改变,造成骨形成减少。     

西布曲明对肥胖小鼠葡萄糖代谢的影响

目的:探讨西布曲明干预对高脂饮食诱导肥胖ICR小鼠葡萄糖代谢的影响。方法:高脂饲料喂养雄性ICR小鼠8周,建立肥胖小鼠模型。西布曲明(7 mg.kg-1.day-1)灌胃干预8周。然后行腹腔注射葡萄糖耐量试验(IPGTT)、胰岛素耐量试验(ITT)及microPET显像;测量小鼠的体重、脂肪组织重量及血生化指标;实时荧光定量RT-PCR方法检测肌肉组织中糖代谢相关基因的相对表达量。结果:西布曲明干预组小鼠体重显著减轻(P<0.05),皮下脂肪、内脏脂肪重量显著降低(P值均小于0.01),空腹血糖显著降低(P<0.05)。ITT试验中,西布曲明干预组小鼠各时间点血糖均低于对照组,差异在90分钟时有显著性(P<0.05);血糖的曲线下面积也显著低于对照组(P<0.05)。另外,西布曲明干预组小鼠的棕色脂肪摄取葡萄糖增多(P<0.05),但肌肉组织内糖代谢相关基因GLUT4、GYS1、HK2、PGC1、IRS1和MSTN的表达量没有显著改变。结论:西布曲明可以减轻小鼠体重,减少白色脂肪重量,增加棕色脂肪代谢能力并在一定程度上改善肥胖小鼠的胰岛素敏感性;西布曲明改善肥胖小鼠葡萄糖代谢的作用可能与肌肉组织中的GLUT4、GYS1、HK2、PGC1、IRS1和MSTN的表达水平无关。     

Pan-PPAR agonist beneficial effects in overweight mice fed a high-fat high-sucrose diet

ObjectiveWe analyzed the effect of peroxisome proliferator-activated receptor (PPAR) agonists on adipose tissue morphology, adiponectin expression, and its relation to glucose and insulin levels in C57BL/6 mice fed a high-fat high-sucrose (HFHS) diet.MethodsMale C57BL/6 mice received one of five diets: standard chow, HFHS chow, or HFHS plus rosiglitazone (PPAR-γ agonist), fenofibrate (PPAR-α agonist), or bezafibrate (pan-PPAR agonist). Diets were administered for 11 wk and medications from week 6 to week 11. Glucose intolerance (GI) and insulin resistance were evaluated by oral glucose tolerance testing and homeostasis model assessment for insulin resistance, respectively. Adipocyte diameter was analyzed in epididymal, inguinal, and retroperitoneal fat pads and by adiponectin immunostain.ResultsMice fed the HFHS chow had hyperglycemia, GI, insulin resistance, increased fat pad weight, adipocyte hypertrophy, and decreased adiponectin immunostaining. Rosiglitazone improved GI, insulin sensitiveness, and adiponectin immunostaining, but it resulted in body weight gain, hyperphagia, and adipocyte and heart hypertrophy. Fenofibrate improved all parameters except for fasting glucose and GI. Bezafibrate was the most efficient in decreasing body weight and glucose intolerance.ConclusionActivation of PPAR-α, -δ, and -γ together is better than the activation of PPAR-α or -γ alone, because bezafibrate showed a wider range of action on metabolic, morphologic, and biometric alterations due to an HFHS diet in mice.     

CYP1B1在成年肥胖小鼠巨噬细胞浸润及组织炎症中的作用

目的探讨CYP1B1(cytochrome P450,family 1,subfamily B,polypeptide 1)缺失对成年小鼠巨噬细胞募集及组织炎症作用。方法选择6 w周龄SPF级CYP1B1基因敲除(KO)和野生型(WT)雄性小鼠,给予低脂肪(LFD)、高脂肪(HFD)饲料,喂养6 w后分别测定各组全血葡萄糖及血清胰岛素水平。利用葡萄糖耐量实验,判断糖耐量损伤情况。HE染色及免疫荧光检测小鼠附睾脂肪组织的巨噬细胞浸润情况。多重实时定量PCR(qRT-PCR)检测附睾脂肪组织及肝脏中巨噬细胞特异性蛋白(Emr1)及肿瘤坏死因子α(TNF-a)的表达水平。结果 CYP1B1敲除可以改善高脂膳食导致的胰岛素敏感性下降;在附睾脂肪组织中,CYP1B1基因缺失与高脂肪膳食均促进巨噬细胞的募集,但CYP1B1缺失抑制高脂膳食对炎症因子的诱导;在肝脏组织中,高脂膳食诱导巨噬细胞的浸润,但CYP1B1基因缺失抑制小鼠巨噬细胞浸润并下调组织炎症因子的表达。结论 CYP1B1基因缺失对高脂膳食诱导的肥胖及相关的胰岛素敏感性下降的保护作用可能是由其对炎症抑制的组织特异性决定的。     

Lipoic acid increases the expression of genes involved in bone formation in mice fed a high-fat diet

Antioxidant lipoic acid (LA) has been reported to have a potential prophylactic effect on bone loss induced by high-fat diet (HFD). The aim of this work was to examine the hypothesis that LA decreases bone resorption-related gene expression and increases bone formation-related gene expression in HFD-fed mice, preventing a shift in the bone metabolism balance toward resorption. Male C57BL/6 mice were fed a normal diet, HFD, or HFD plus 0.1% LA for 12 weeks. The bone metabolism-related genes differentially expressed between mice fed HFD and those fed HFD supplemented with LA were identified through complementary DNA microarray. The supplemental LA significantly increased bone mineral density and bone antioxidant capacity in mice fed HFD (P < .05). Compared with the HFD-fed mice, LA induced the decreased expression of genes associated with bone resorption, such as Mmp9 (1.9-fold) and Ctsk (2.3-fold), and increased those genes associated with bone formation, such as Col1a1 (1.3-fold) and Alp1 (1.5-fold). Furthermore, LA upregulated many genes involved in the Igf signaling pathway, such as Igf-1 (increased 1.7-fold), and downregulated genes involved in the p53 apoptotic pathway, such as p53 (decreased 2.3-fold), thus attenuating the HFD-induced inhibition of bone formation. Lipoic acid induced upregulation of Il12a (2.1-fold) and downregulation of Tgfbr1 (4.3-fold) and Il17a (11.3-fold), which may reduce bone resorption. In summary, LA supplementation during HFD could affect bone density, altering gene expression.     

Anti-Obesity and Antidiabetic Effects of Nelumbinis Semen Powder in High-Fat Diet-Induced Obese C57BL/6 Mice

Nelumbinis Semen (NS, the seeds of Nelumbo nucifera) extract is a traditional Korean medicine with anti-oxidant activity. The present study examined the anti-obesity and antidiabetic effects of NS powder in high-fat diet (HFD)-induced obese C57BL/6 mice. Mice (n = 8/group) were fed a normal diet (CON), HFD, HFD containing 5% NS powder (HFD-NS5%), or HFD containing 10% NS powder (HFD-NS10%) for 12 weeks. Food intake was relatively higher in groups HFD-NS5% and HFD-NS10%, while the food efficiency ratio was highest in group HFD (p < 0.05). HFD-NS5% reduced the body weight (−39.1%) and fat weight (−26.6%), including epididymal fat and perirenal fat, and lowered the serum triglyceride levels (−20.6%) compared with HFD. Groups HFD-NS5% and HFD-NS10% showed hepatoprotective properties, reducing the serum ALT levels (p < 0.05) and fat globules (size and number) in the liver compared with group HFD. HFD-NS5% and HFD-NS10% regulated the blood glucose, improved the glucose intolerance, and showed a 12.5% and 15.0% reduction in the area under the curve (AUC) of intraperitoneal glucose tolerance test (IPGTT), and a 26.8% and 47.3% improvement in homeostatic model assessment insulin resistance (HOMA-IR), respectively, compared with HFD (p < 0.05). Regarding the expressions of genes related to anti-obesity and antidiabetes, there was a 1.7- and 1.3-fold increase in PPAR-α protein expression, 1.4- and 1.6-fold increase in PPAR-γ protein expression, and 0.7- and 0.6-fold decrease in TNF-α protein expression, respectively, following HFD-NS5% and HFD-NS10% treatments, compared with HFD, and GLUT4 protein expression increased relative to CON (p < 0.05). These results comprehensively provide the fundamental data for NS powder’s functional and health-promoting benefits associated with anti-obesity and antidiabetes.     

Differential Development of Glucose Intolerance and Pancreatic Islet Adaptation in Multiple Diet Induced Obesity Models

Background: The C57BL/6 mouse fed a high fat diet is a common and valuable model in experimental studies of obesity and type 2 diabetes (T2D). Different high fat diets are used and in order to determine which diet produces a model most accurately resembling human T2D, they need to be compared head-to-head. Methods: Four different diets, the 60% high fat diet (HFD) and the 58% high fat-high sucrose Surwit diet (HFHS) and their respective controls, were compared in C57BL/6J mice using glucose tolerance tests (IVGTT) and the euglycemic clamp. Results: Mice fed a HFD gained more weight than HFHS fed mice despite having similar energy intake. Both high fat diet models were glucose intolerant after eight weeks. Mice fed the HFD had elevated basal insulin, which was not seen in the HFHS group. The acute insulin response (AIR) was unchanged in the HFD group, but slightly increased in the HFHS diet group. The HFHS diet group had a threefold greater total insulin secretion during the IVGTT compared to its control, while no differences were seen in the HFD group. Insulin sensitivity was decreased fourfold in the HFD group, but not in the HFHS diet group. Conclusion: The HFD and HFHS diet models show differential effects on the development of insulin resistance and beta cell adaptation. These discrepancies are important to acknowledge in order to select the appropriate diet for specific studies.     

Effects of Combined Exposure to Lead and High-Fat Diet on Bone Quality in Juvenile Male Mice

Background

Lead (Pb) exposure and obesity are co-occurring risk factors for decreased bone mass in the young, particularly in low socioeconomic communities.

Objectives

The goal of this study was to determine whether the comorbidities of Pb exposure and high-fat diet–induced obesity amplify skeletal deficits independently associated with each of these risk factors, and to explore associated mechanisms of the observed deficiencies.

Methods

Five-week-old male C57BL/6J mice were placed on low-fat (10% kcal, LFD) or high-fat (60% kcal, HFD) diets for 12 weeks. Mice were exposed to lifetime Pb (50 ppm) through drinking water.

Results

HFD was associated with increased body mass and glucose intolerance. Both HFD and Pb increased fasting glucose and serum leptin levels. Pb and HFD each reduced trabecular bone quality and together had a further detrimental effect on these bone parameters. Mechanical bone properties of strength were depressed in Pb-exposed bones, but HFD had no significant effect. Both Pb and HFD altered progenitor cell differentiation, promoting osteoclastogenesis and increasing adipogenesis while suppressing osteoblastogenesis. In support of this lineage shift being mediated through altered Wnt signaling, Pb and non-esterified fatty acids in MC3T3 cells increased in vitro PPAR-γ activity and inhibited β-catenin activity. Combining Pb and non-esterified fatty acids enhanced these effects.

Conclusions

Pb and HFD produced selective deficits in bone accrual that were associated with alterations in progenitor cell activity that may involve reduced Wnt signaling. This study emphasizes the need to assess toxicants together with other risk factors relevant to human health and disease.

Citation

Beier EE, Inzana JA, Sheu TJ, Shu L, Puzas JE, Mooney RA. 2015. Effects of combined exposure to lead and high-fat diet on bone quality in juvenile male mice. Environ Health Perspect 123:935–943; http://dx.doi.org/10.1289/ehp.1408581     

High Fructose and High Fat Exert Different Effects on Changes in Trabecular Bone Micro-structure

Objectives

To compare the effects of high-fat diet (HFD) and high-fructose diet (HFrD) on bone metabolism at different time points, dynamically observe the bone histology and femur trabecular micro-architecture, and analyze the underlying mechanisms.

Methods

Sixty–Five male 6- to 7-week-old C57BL/6J mice were given HFD, HFrD, or standard diets (SD) for 8, 16, and 24 weeks. Micro-computed tomography (μCT) and bone histology were used to measure bone mass and trabecular micro-structure. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to determine the expression of genes related to bone and lipid metabolisms.

Results

Compared to SD mice, femoral trabecular bone mass was significantly increased in both HFrD mice and HFD mice at 8 weeks, it continued to be higher in HFrD mice at 16 and 24 weeks with the highest level at 16 weeks, but it was significantly decreased in HFD mice at 16 and 24 weeks. HFD mice showed more epididymal fat accumulation than HFrD mice. mRNA expression of Runx2 was up-regulated at 8 and 16 weeks, but down-regulated at 24 weeks similarly in both HFrD mice and HFD mice. mRNA expression of MMP9 and CTSK was up-regulated at 8 and 16 weeks in HFD mice, but down-regulated at 24 weeks in both HFrD mice and HFD mice.

Conclusions

Our data indicated that the HFrD and HFD had different modulating effects on bone mass. After short-term feeding, both HFrD and HFD showed positive effects on bone mass; however, after long-term feeding, bone mass was decreased in HFD mice. In contrast, the bone mass was first increased and then decreased in the HFrD mice. On the basis of these findings, we speculated that chronic consumption of fat and fructose would exert detrimental effects on bone mass which might a combination action of body mass, fat mass, and bone formation/bone resorption along with proinflammatory factor and bone marrow environment.

     

Norepinephrine- and epinephrine-deficient mice gain weight normally on a high-fat diet

OBJECTIVE: Signaling through adrenergic receptors (ARs) by norepinephrine (NE) and epinephrine (Epi) regulates weight gain when mice are fed a high-fat diet (HFD) by controlling diet-induced thermogenesis. Thus, one would predict that mice unable to make NE/Epi because of inactivation of the dopamine beta-hydroxylase gene (Dbh-null mice) would have a propensity to become obese. We characterized the response of Dbh-null and control mice to a HFD. RESEARCH METHODS AND PROCEDURES: Dbh-null and control mice were fed an HFD or a regular diet (RD) for 2 months. Body weight, adiposity, muscle triglyceride levels, and adipocyte size were measured, as were circulating leptin, adiponectin, triglyceride, glucose, and insulin levels. A glucose tolerance test was also preformed. RESULTS: Dbh-null mice gain weight normally on an HFD and have the same adiposity. Their serum triglyceride and leptin levels are normal, but adipocytes are approximately 30% smaller than controls. Dbh-null mice maintain low blood glucose levels and glucose tolerance when exposed to the HFD in contrast to controls. DISCUSSION: Complete lack of NE/Epi does not predispose to obesity. Because mice lacking all three betaARs become obese on an HFD, an imbalance of signaling through alpha- and betaARs seems to be responsible for obesity. Surprisingly, Dbh-null mice maintain glucose tolerance.     

高脂饮食及罗格列酮对C57BL／6小鼠肝脏AGFmRNA表达的影响

目的探讨小鼠肝脏组织血管生成素相关生长因子（Angiopietin—related growth factor,AGF）mRNA表达水平的变化与胰岛素抵抗的关系。方法将雄性C57BIM6小鼠以高脂饮食喂养10周,建立胰岛素抵抗模型,再以罗格列酮灌胃8周;实验结束时以口服糖耐量试验、HOMA评分评价实验小鼠血糖、胰岛素抵抗水平,用RT-PCR技术检测这三组小鼠肝脏组织AGFmRNA的表达,并进行统计学分析。结果高脂饮食组小鼠肝脏AGFmRNA的表达低于对照组,差异具有统计学意义（P〈0．05）,罗格列酮组灌胃后小鼠肝脏AGFmRNA的表达增加（P〈0．01）;相关分析显示小鼠肝脏AGFmRNA表达与血浆胰岛素水平呈负相关（r=-0．516,P〈0．05）。结论高脂饮食诱导小鼠血浆葡萄糖及胰岛素水平增高,肝脏AGFmRNA表达降低,当胰岛素抵抗程度得到改善时,AGF的表达随之增加。     

Energetic determinants of glucose tolerance status in Jamaican adults

As type 2 diabetes mellitus (DM2), obesity and sedentary lifestyles are increasing in developing countries, this observational study investigated the role of physical activity on DM2 in Jamaica. Anthropometry, body composition (by bioelectrical impedance analysis) and glucose tolerance status was assessed in 722 adults in 1993 and 1997. Energy expenditure was estimated in a subset using measured resting energy expenditure in combination with self-reported activity recalls. The rates of impaired glucose tolerance (IGT) were 23.7 and 27.3%, and DM2 were 16.3 and 23.7% among men and women, respectively. After adjusting for body composition, a one-unit increase in physical activity significantly reduced the odds of having diabetes (OR = 0.05; 95% CI: 0.004, 0.66), but not IGT. Hence, decreased physical activity is a significant independent contributor to the high rates of glucose intolerance in Jamaica. Efforts must be directed at minimizing obesity and increasing physical activity in developing countries.     

Diffuse idiopathic skeletal hyperostosis in diabetes mellitus, impaired glucose tolerance and obesity

BACKGROUND: Diffuse idiopathic skeletal hyperostosis (DISH) is a rheumatic disease characterized by a significant association with metabolic alterations, such as an impaired lipidic profile. METHODS: One-hundred-thirty consecutive patients and 40 normal subjects were studied. The patients were affected by type 1 and type 2 diabetes mellitus, impaired glucose tolerance and obesity. The diagnosis of DISH was performed by clinical examination and X-ray study of the thoracolumbar spine. The determination of total cholesterol, triglycerides, HLD-cholesterol and LDL-cholesterol was realized by routine biochemical methods; an oral glucose tolerance test was performed in order to determine the levels of C-peptide and blood glucose. RESULTS: We demonstrate a high incidence of the disease in a cohort of patients affected by overt and non-overt diabetes mellitus (T1DM and T2DM) as well as in obese subjects and a correlation between this disorder and hypertryglyceridemia (T1DM, obese-T2DM and obese patients), hypo-HDL-cholesterolemia (obese-T2DM, non-obese-T2DM and obese patients) and hyper-LDL-cholesterolemia (obese patients). In obese-T2DM patients, as well as in obese patients, we observed 40% of DISH, in non obese-T2DM patients the presence of DISH was 30%, while in T1DM patients and impaired glucose tolerance 26.6% and 22.2, respectively. However, a correlation between DISH and the relative hyperinsulinemia in obese patients during an oral glucose tolerance test is not documented. CONCLUSIONS: Our study confirms the prevalence of DISH in diabetes mellitus and obesity, the association with an impaired lipidic profile and the low percentage of symptomatic patients.     

Anti-inflammatory and anti-diabetic effects of brown seaweeds in high-fat diet-induced obese mice

BACKGROUND/OBJECTIVESSeaweeds have been reported to have various health beneficial effects. In this study, we investigated the potential anti-obesity and anti-inflammatory effects of four types of domestic brown seaweeds in a high-fat diet-induced obese mouse model and bone marrow-derived macrophages (BMDM).MATERIALS/METHODSMale C57BL/6N mice were fed low-fat diet (LFD), high-fat diet (HFD) or HFD containing Undaria Pinnatifida, HFD containing Laminaria Japonica (LJ), HFD containing Sargassum Fulvellum, or HFD containing Hizikia Fusiforme (HF) for 16 weeks.RESULTSBrown seaweed supplementation did not affect long-term HFD-associated changes in body weight or adiposity, although mice fed HFD + LJ or HFD + HF gained slightly less body weight compared with those fed HFD at the beginning of feeding. Despite being obese, mice fed HFD + LJ appeared to show improved insulin sensitivity compared to mice fed HFD. Consistently, we observed significantly reduced blood glucose concentrations in mice fed HFD + LJ compared with those of mice fed HFD. Although no significant differences in adipocyte size were detected among the HFD-fed groups, consumption of seaweeds decreased formation of HFD-induced crown-like structures in gonadal adipose tissue as well as plasma inflammatory cytokines. BMDM from mice fed HFDs with seaweeds showed differential regulation of pro-inflammatory cytokines such as IL-1β and IL-6 compared with BMDM from mice fed HFD by LPS stimulation.CONCLUSIONAlthough seaweed consumption did not prevent long-term HFD-induced obesity in C57BL/6N mice, it reduced insulin resistance (IR) and circulation of pro-inflammatory cytokines. Therefore, seaweeds may ameliorate systemic inflammation and IR in obesity partially due to inhibition of inflammatory signaling in adipose tissue cells as well as bone marrow-derived immune cells.     

Astaxanthin,a Marine Carotenoid,Maintains the Tolerance and Integrity of Adipose Tissue and Contributes to Its Healthy Functions

Recently, obesity-induced insulin resistance, type 2 diabetes, and cardiovascular disease have become major social problems. We have previously shown that Astaxanthin (AX), which is a natural antioxidant, significantly ameliorates obesity-induced glucose intolerance and insulin resistance. It is well known that AX is a strong lipophilic antioxidant and has been shown to be beneficial for acute inflammation. However, the actual effects of AX on chronic inflammation in adipose tissue (AT) remain unclear. To observe the effects of AX on AT functions in obese mice, we fed six-week-old male C57BL/6J on high-fat-diet (HFD) supplemented with or without 0.02% of AX for 24 weeks. We determined the effect of AX at 10 and 24 weeks of HFD with or without AX on various parameters including insulin sensitivity, glucose tolerance, inflammation, and mitochondrial function in AT. We found that AX significantly reduced oxidative stress and macrophage infiltration into AT, as well as maintaining healthy AT function. Furthermore, AX prevented pathological AT remodeling probably caused by hypoxia in AT. Collectively, AX treatment exerted anti-inflammatory effects via its antioxidant activity in AT, maintained the vascular structure of AT and preserved the stem cells and progenitor’s niche, and enhanced anti-inflammatory hypoxia induction factor-2α-dominant hypoxic response. Through these mechanisms of action, it prevented the pathological remodeling of AT and maintained its integrity.