The Effect of Isoleucine Supplementation on Body Weight Gain and Blood Glucose Response in Lean and Obese Mice.

Chronic isoleucine supplementation prevents diet-induced weight gain in rodents. Acute-isoleucine administration improves glucose tolerance in rodents and reduces postprandial glucose levels in humans. However, the effect of chronic-isoleucine supplementation on body weight and glucose tolerance in obesity is unknown. This study aimed to investigate the impact of chronic isoleucine on body weight gain and glucose tolerance in lean and high-fat-diet (HFD) induced-obese mice. Male C57BL/6-mice, fed a standard-laboratory-diet (SLD) or HFD for 12 weeks, were randomly allocated to: (1) Control: Drinking water; (2) Acute: Drinking water with a gavage of isoleucine (300 mg/kg) prior to the oral-glucose-tolerance-test (OGTT) or gastric-emptying-breath-test (GEBT); (3) Chronic: Drinking water with 1.5% isoleucine, for a further six weeks. At 16 weeks, an OGTT and GEBT was performed and at 17 weeks metabolic monitoring. In SLD- and HFD-mice, there was no difference in body weight, fat mass, and plasma lipid profiles between isoleucine treatment groups. Acute-isoleucine did not improve glucose tolerance in SLD- or HFD-mice. Chronic-isoleucine impaired glucose tolerance in SLD-mice. There was no difference in gastric emptying between any groups. Chronic-isoleucine did not alter energy intake, energy expenditure, or respiratory quotient in SLD- or HFD-mice. In conclusion, chronic isoleucine supplementation may not be an effective treatment for obesity or glucose intolerance.

An oral supplementation based on myo-inositol, folic acid and liposomal magnesium may act synergistically with antibiotic therapy and can improve metabolic profile in patients affected by Hidradenitis suppurativa: our experience.

BACKGROUND: Over recent years, the link between obesity, metabolic syndrome and Hidradenitis suppurativa (HS) has been explored. It has been demonstrated that HS patients have a high prevalence of the metabolic syndrome and an increased frequency of insulin resistance. The objective of our study is to estimate the effectiveness of an oral supplementation based on myo-inositol (MI), folic acid and liposomal magnesium (Levigon®, Sanitpharma; Milan, Italy) on the clinical and metabolic profile of patients affected by HS. METHODS: Twenty subjects with HS and an impaired glucose metabolism were enrolled. Group A: 10 subjects received for 6 months MI 2000 mg, liposomal magnesium and folic acid associated to topical antibiotic therapy (clindamycin gel 1%), systemic antibiotic therapy (clindamycin 300 mg b.i.d. and rifampicin 600 mg daily for 6 weeks) and a normocaloric diet group B: 10 subjects received topical and systemic antibiotic therapy associated to a normocaloric diet for 6 months. RESULTS: After 6 months group A patients showed an average reduction of Sartorius Score from 38.3±7.75 to 27.3±13.53 (P value <0.04) while in the control group there was a reduction of the Sartorius from 38.4±7.88 to 31.1±8.02 (P value =0.55). Moreover in group A Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) was significantly reduced from 2.43±0.35 to 2.1±0.31 (P<0.01) whereas in group B HOMA-IR did not significantly decrease (2.51±0.65 at T0 at 2.40±0.67 at T1). CONCLUSIONS: Our study underlines the importance of the evaluation of metabolic profile in patients with HS. Moreover, it suggests that the supplementation of MI, folic acid and liposomal magnesium in HS can improve the efficacy of concomitant therapies and the metabolic profile.

Effect of annatto-extracted tocotrienols and green tea polyphenols on glucose homeostasis and skeletal muscle metabolism in obese male mice.

Skeletal muscle is the major site for glucose uptake and thus plays an important role in initiating insulin resistance in type 2 diabetes mellitus. This study evaluated the effects of tocotrienols (TT) and green tea polyphenols (GTP) individually or in combination on glucose homeostasis and skeletal muscle metabolism in obese mice with insulin resistance and elevation of blood glucose. Forty-eight male mice were fed a high-fat diet and assigned to 4 groups in a 2 (no TT vs. 400 mg TT/kg diet) × 2 (no GTP vs. 0.5% vol/wt GTP in water) for 14 weeks. Both GTP and TT improved area under curve of insulin intolerance; while GTP increased serum insulin levels in obese mice, probably due to the addition of sweetener in drinking water. An interaction (TT×GTP) was observed in glucose tolerance test, total pancreas insulin concentration, and citrate synthase activity of soleus in mice. Neither TT nor GTP affected insulin and glucagon protein expression in pancreas based on immunohistochemistry. Both TT and GTP individually increased soleus muscle weight of mice; while only GTP increased gastrocnemius muscle weight of mice. The TT+GTP group had the greatest gastrocnemius muscle cross sectional area than other groups. GTP, not TT, induced cytochrome c oxidase activity and reduced thiobarbituric acid reactive substances levels in soleus muscle. Our results suggest that TT and GTP, individually or synergistically have the potential to improve skeletal muscle metabolism in obese mice by improving glucose homeostasis, reducing lipid peroxidation, and increasing rate limiting enzymes of oxidative phosphorylation.

Fish Oil Protects Wild Type and Uncoupling Protein 1-Deficient Mice from Obesity and Glucose Intolerance by Increasing Energy Expenditure.

SCOPE: The mechanisms and involvement of uncoupling protein 1 (UCP1) in the protection from obesity and insulin resistance induced by intake of a high-fat diet rich in omega-3 (n-3) fatty acids are investigated. METHODS AND RESULTS: C57BL/6J mice are fed either a low-fat (control group) or one of two isocaloric high-fat diets containing either lard (HFD) or fish oil (HFN3) as fat source and evaluated for body weight, adiposity, energy expenditure, glucose homeostasis, and inguinal white and interscapular brown adipose tissue (iWAT and iBAT, respectively) gene expression, lipidome, and mitochondrial bioenergetics. HFN3 intake protected from obesity, glucose and insulin intolerances, and hyperinsulinemia. This is associated with increased energy expenditure, iWAT UCP1 expression, and incorporation of n-3 eicosapentaenoic and docosahexaenoic fatty acids in iWAT and iBAT triacylglycerol. Importantly, HFN3 is equally effective in reducing body weight gain, adiposity, and glucose intolerance and increasing energy expenditure in wild-type and UCP1-deficient mice without recruiting other thermogenic processes in iWAT and iBAT, such as mitochondrial uncoupling and SERCA-mediated calcium and creatine-driven substrate cyclings. CONCLUSION: Intake of a high-fat diet rich in omega-3 fatty acids protects both wild-type and UCP1-deficient mice from obesity and insulin resistance by increasing energy expenditure through unknown mechanisms.

Does L-leucine supplementation cause any effect on glucose homeostasis in rodent models of glucose intolerance? A systematic review.

L-Leucine has been used to improve metabolic outcomes in glucose-intolerant rodent models. However, because studies have used different experimental models and conditions it is difficult to establish the best approach for new clinical trials evaluating the potential effects of L-leucine on glucose homeostasis. We performed a systematic review to report the effect of L-leucine supplementation on glucose homeostasis in rodents with glucose intolerance. The search engines MEDLINE and ScienceDirect were applied using MeSH terms. Thirty-four studies were included in this systematic review. Based on the current data, ingestion of 90-140 mg day-1 of isolated L-leucine in diet-induced obesity (DIO) models shows improvement in metabolic markers if offered during the development of the metabolic disorder in almost all the studies, but not after. Branched-chain amino acid supplementation was effective in streptozotocin-induced ß-cells death but not in DIO models. L-Leucine supplementation seems to have an optimal dose and timing for supplementation to improve glucose homeostasis in DIO.

Maternal metabolic response to dietary treatment for impaired glucose tolerance and gestational diabetes mellitus.

BACKGROUND: Dietary advice is a standard component of treatment for pregnant women with impaired glucose tolerance (IGT) and gestational diabetes (GDM), yet few studies report glycemic profiles in response to dietary therapies and the optimal dietary approach remains uncertain. AIM: To assess changes in maternal glycemic profile and pregnancy outcomes among women with diet-controlled IGT and GDM. METHODS: Pregnant women who had one or more elevated values on a 3-h oral glucose tolerance test were enrolled. All participants received dietary advice and glucose monitoring as part of routine clinical care. Fasting and 1-h post-prandial blood samples, collected prior to initiation of clinical treatment and repeated 4-6 weeks later, were analyzed for glucose, insulin, and C-peptide. Homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. Women who required pharmacological therapy for glucose control were excluded from analyses. RESULTS: Participants (N = 93) were of moderately older age (mean 33 years), with a high rate of overweight/obesity (mean body mass index (BMI) = 28.65 kg/m2), and were diagnosed late in gestation (mean 29 weeks). Fasting (mean ± SD 4.82 ± 0.53 to 4.60 ± 0.42 mmol/l; p < 0.001) and post-prandial glucose (7.01 ± 1.19 to 6.47 ± 1.10; p = 0.004) decreased significantly following the intervention. Baseline HOMA-IR was elevated (3.12 ± 1.03) but did not significantly decrease (2.78 ± 1.52; p = 0.066). There were high rates of macrosomia (24.7%) and cesarean delivery (32.3%). CONCLUSIONS: Although improvements in blood glucose levels were observed among women with diet-controlled IGT and GDM, this was insufficient to significantly affect insulin resistance or perinatal outcome. Late diagnosis and treatment of IGT/GDM may have contributed to such outcomes.

Comparison between pre-exercise casein peptide and intact casein supplementation on glucose tolerance in mice fed a high-fat diet.

We hypothesized that along with exercise, casein peptide supplementation would have a higher impact on improving glucose tolerance than intact casein. Male 6-week-old ICR mice were provided a high-fat diet to induce obesity and glucose intolerance. The mice were randomly divided into 4 treatment groups: control (Con), endurance training (Tr), endurance training with intact casein supplementation (Cas+Tr), and endurance training with casein peptide supplementation (CP+Tr). The mice in each group were orally administrated water, intact casein, or casein peptide (1.0 mg/g body weight, every day), and then subjected to endurance training (15-25 m/min, 60 min, 5 times/week for 4 weeks) on a motor-driven treadmill 30 min after ingestion. Our results revealed that total intra-abdominal fat was significantly lower in CP+Tr than in Con (p < 0.05). Following an oral glucose tolerance test, the blood glucose area under the curve (AUC) was found to be significantly smaller for CP+Tr than for Con (p < 0.05). Moreover, in the soleus muscle, glucose transporter 4 (GLUT4) protein levels were significantly higher in CP+Tr than in Con (p < 0.01). However, intra-abdominal fat, blood glucose AUC, and GLUT4 protein content in the soleus muscle did not alter in Tr and Cas+Tr when compared with Con. These observations suggest that pre-exercise casein peptide supplementation has a higher effect on improving glucose tolerance than intact casein does in mice fed a high-fat diet.

Dietary Pea Fiber Supplementation Improves Glycemia and Induces Changes in the Composition of Gut Microbiota, Serum Short Chain Fatty Acid Profile and Expression of Mucins in Glucose Intolerant Rats.

Several studies have demonstrated the beneficial impact of dried peas and their components on glucose tolerance; however, the role of gut microbiota as a potential mediator is not fully examined. In this study, we investigated the effect of dietary supplementation with raw and cooked pea seed coats (PSC) on glucose tolerance, microbial composition of the gut, select markers of intestinal barrier function, and short chain fatty acid profile in glucose intolerant rats. Male Sprague Dawley rats were fed high fat diet (HFD) for six weeks to induce glucose intolerance, followed by four weeks of feeding PSC-supplemented diets. Cooked PSC improved glucose tolerance by approximately 30% (p < 0.05), and raw and cooked PSC diets reduced insulin response by 53% and 56% respectively (p < 0.05 and p < 0.01), compared to HFD (containing cellulose as the source of dietary fiber). 16S rRNA gene sequencing on fecal samples showed a significant shift in the overall microbial composition of PSC groups when compared to HFD and low fat diet (LFD) controls. At the family level, PSC increased the abundance of Lachnospiraceae and Prevotellaceae (p < 0.001), and decreased Porphyromonadaceae (p < 0.01) compared with HFD. This was accompanied by increased mRNA expression of mucin genes Muc1, Muc2, and Muc4 in ileal epithelium (p < 0.05). Serum levels of acetate and propionate increased with raw PSC diet (p < 0.01). These results indicate that supplementation of HFD with PSC fractions can improve glycemia and may have a protective role against HFD-induced alterations in gut microbiota and mucus layer.

Effects of a whey protein supplementation on oxidative stress, body composition and glucose metabolism among overweight people affected by diabetes mellitus or impaired fasting glucose: A pilot study.

Obesity and diabetes mellitus type 2 (DM2) are characterized by chronic inflammation and oxidative stress [Donath et al. 2013] and this leads to cardiovascular diseases [Hulsmans & Holvoet 2010]. Whey proteins (WP) have antioxidant [Chitapanarux et al. 2009], anti-inflammatory [Sugawara et al. 2012] and hypoglycemic activities [Mignone et al. 2015], while data on weight, body composition [Frestedt et al. 2008; Aldrich et al. 2011] and blood pressure are conflicting [Kawase et al. 2000; Lee et al. 2007]. WP have unpleasant taste and smell [Patel 2015], but a new WP isolate (ProLYOtin®) seems to be more palatable. 40 g/die of ProLYOtin® were supplemented to overweight people (n=31) with impaired fasting glucose/DM2 for 12 weeks. Markers of antioxidant status (total antioxidant status, glutathione peroxidase, glutathione reductase, uric acid), oxidative damage (thiobarbituric acid reactive substances, advanced oxidation protein products, 8-hydroxydeoxyguanosine), inflammation (interleukin-6, high sensitive reactive protein C) and glicemic status (fasting glucose, insulin, glycated hemoglobin), anthropometric data (weight, height, waist circumference), body composition (body cell mass, fat mass), blood pressure, hand grip strength and skin autofluorescence were measured before and at the end of supplementation. Isolate palatability was evaluated. An increase in glutathione peroxidase, a decrease in uric acid and no change in glutathione reductase, total antioxidant status, oxidative damage, inflammation and glucose markers were found. Significant improvements in anthropometric parameters and fat mass were detected. There wasn't any change in blood pressure, skin autofluorescence and physical performance. Two-thirds of subjects judged the supplement positively. ProLYOtin® seems suitable for treatment of OS and overweight.

Supplementation of Syzygium cumini seed powder prevented obesity, glucose intolerance, hyperlipidemia and oxidative stress in high carbohydrate high fat diet induced obese rats.

BACKGROUND: Obesity and related complications have now became epidemic both in developed and developing countries. Cafeteria type diet mainly composed of high fat high carbohydrate components which plays a significant role in the development of obesity and metabolic syndrome. This study investigated the effect of Syzygium cumini seed powder on fat accumulation and dyslipidemia in high carbohydrate high fat diet (HCHF) induced obese rats. METHOD: Male Wistar rats were fed with HCHF diet ad libitum, and the rats on HCHF diet were supplemented with Syzygium cumini seed powder for 56 days (2.5% w/w of diet). Oral glucose tolerance test, lipid parameters, liver marker enzymes (AST, ALT and ALP) and lipid peroxidation products were analyzed at the end of 56 days. Moreover, antioxidant enzyme activities were also measured in all groups of rats. RESULTS: Supplementation with Syzygium cumini seed powder significantly reduced body weight gain, white adipose tissue (WAT) weights, blood glucose, serum insulin, and plasma lipids such as total cholesterol, triglyceride, LDL and HDL concentration. Syzygium cumini seed powder supplementation in HCHF rats improved serum aspartate amino transferase (AST), alanine amino transferase (ALT), and alkaline phosphatase (ALP) activities. Syzygium cumini seed powder supplementation also reduced the hepatic thiobarbituric acid reactive substances (TBARS) and elevated the antioxidant enzyme superoxide dismutase (SOD) and catalase (CAT) activities as well as increased glutathione (GSH) concentration. In addition, histological assessment showed that Syzygium cumini seed powder supplementation prevented inflammatory cell infiltration; fatty droplet deposition and fibrosis in liver of HCHFD fed rats. CONCLUSION: Our investigation suggests that Syzygium cumini seed powder supplementation prevents oxidative stress and showed anti-inflammatory and antifibrotic activity in liver of HCHF diet fed rats. In addition, Syzygium cumini seed powder may be beneficial in ameliorating insulin resistance and dyslipidemia probably by increasing lipid metabolism in liver of HCHF diet fed rats.

Effect of dry tomato peel supplementation on glucose tolerance, insulin resistance, and hepatic markers in mice fed high-saturated-fat/high-cholesterol diets.

Many studies have investigated the effect of crude tomato peel in vivo, but no studies have determined the dose-effect of dry tomato peel (DTP) on glucose intolerance, insulin resistance, and atherogenic dyslipidemia induced by a high-saturated-fat (HSF) diet in vivo. The aim of this study was to investigate the effects of different doses of DTP on the levels of oxidative stress in mice fed an HSF and cholesterol-rich diet for 12 weeks. The main outcomes are glucose and insulin tolerance, plasma lipids, and hepatic steatosis and inflammation. BALB/c male mice (n=40) (8 weeks old, weighing 22.2±1.0 g) were divided into four treatment groups (10 mice/group): (a) high-fat control diet (HF Ctrl), which contains sunflower oil as a sole source of fat; (b) HSF/high-cholesterol (HC) diet; (c) HSF/HC diet supplemented with 9% DTP and (d) HSF/HC diet supplemented with 17% DTP. The HSF/HC diet significantly increased body weight gain, adipose tissue weight, fasting plasma glucose, fasting plasma insulin and lipid peroxidation and caused the development of liver steatosis and inflammation. Supplementation with DTP increased plasma lycopene concentration and reduced the development of indicators of metabolic syndrome, with no consistent effect of the DTP dose. Hepatic steatosis and inflammation were not reversed with DTP supplementation. Among mice fed the HSF/HC diet, DTP supplementation appears to have a beneficial effect on insulin resistance, which confirms the antiatherogenic effect of DTP.

Mechanisms by which cocoa flavanols improve metabolic syndrome and related disorders.

Dietary administration of cocoa flavanols may be an effective complementary strategy for alleviation or prevention of metabolic syndrome, particularly glucose intolerance. The complex flavanol composition of cocoa provides the ability to interact with a variety of molecules, thus allowing numerous opportunities to ameliorate metabolic diseases. These interactions likely occur primarily in the gastrointestinal tract, where native cocoa flavanol concentration is high. Flavanols may antagonize digestive enzymes and glucose transporters, causing a reduction in glucose excursion, which helps patients with metabolic disorders maintain glucose homeostasis. Unabsorbed flavanols, and ones that undergo enterohepatic recycling, will proceed to the colon where they can exert prebiotic effects on the gut microbiota. Interactions with the gut microbiota may improve gut barrier function, resulting in attenuated endotoxin absorption. Cocoa may also positively influence insulin signaling, possibly by relieving insulin-signaling pathways from oxidative stress and inflammation and/or via a heightened incretin response. The purpose of this review is to explore the mechanisms that underlie these outcomes, critically review the current body of literature related to those mechanisms, explore the implications of these mechanisms for therapeutic utility, and identify emerging or needed areas of research that could advance our understanding of the mechanisms of action and therapeutic potential of cocoa flavanols.

Dietary supplementation with Lactobacillus plantarum dy-1 fermented barley suppresses body weight gain in high-fat diet-induced obese rats.

BACKGROUND: Cereal fermentations have shown significant potential in improvement and design of the nutritional quality and health effects of foods and ingredients. In the present study, the effect of supplementary Lactobacillus plantarum dy-1 fermented barley (LFB) on obesity in high-fat diet (HFD)-induced obese rats was investigated. RESULTS: LFB treatment showed a lower rate of increase in body weight and percentage of body fat and a reversal of HFD-induced glucose intolerance, with ameliorated hyperinsulinemia, decreased levels of triglycerides and total cholesterol, and inhibited concentration of interleukin (IL)-1ß, IL-6 and tumor necrosis factor-α. Moreover, LFB treatment also showed the strongest inhibition of nuclear factor (NF)-kB activation and exhibited the greatest effects in blocking the degradation of the inhibitor of NF-kB and inhibiting p38 and JNK1 phosphorylation compared with HFD and raw barley treatment. CONCLUSIONS: It was clear that Lactobacillus plantarum dy-1 fermentation significantly improves the anti-obesity properties of barley. The results establish the foundation for ameliorating diet-induced obesity of product with LFB as nutritional supplements. © 2016 Society of Chemical Industry.

Effects of n-3 pufas on fasting plasma glucose and insulin resistance in patients with impaired fasting glucose or impaired glucose tolerance.

AIM: to evaluate if a supplementation with n-3 PUFAs at high doses could give a regression of the condition of impaired glycemia. METHODS: we enrolled 281 overweight/obese patients with impaired fasting glucose (IFG) or impaired glucose tolerance (IGT); 138 subjects were randomized to n-3 PUFAs group, 1 g three times a day, and 143 to placebo for 18 months. We assessed at baseline, and after 9, and 18 months: circumferences, body mass index (BMI), fasting plasma glucose (FPG), fasting plasma insulin (FPI), HOMA-index, lipid profile. At baseline and at the end of the study, all patients underwent an oral glucose tolerance test (OGTT). RESULTS: we observed a decrease of glycemia and HOMA-IR with n-3 PUFAs, compared to baseline, and to placebo. Fasting plasma insulin decreased with n-3 PUFAs and increased with placebo. HDL-cholesterol increased after 18 months of n-3 PUFAs, while triglycerides decreased compared to baseline and to placebo. After OGTT performed at the end of the study, more patients returned to a condition of euglycemia with n-3 PUFAs compared to placebo. CONCLUSIONS: n-3 PUFAs were effective in reducing glycemia in patients affected by IFG or IGT and seem to be helpful to slow the development of type 2 diabetes mellitus. © 2016 BioFactors, 42(3):316-322, 2016.

Influence of medical nutrition therapy on borderline glucose intolerance in pregnant Taiwanese women.

OBJECTIVE: To investigate the influence of medical nutrition therapy (MNT) on borderline glucose intolerance (BGI) in pregnant Taiwanese women. METHODS: A total of 5194 singleton pregnant women were enrolled in this prospective, non-randomized study. The participants were subjected to the 50 g 1-h glucose challenge test (GCT) and 100 g 3-h oral glucose tolerance test (OGTT) to screening gestational diabetes mellitus (GDM). BGI was defined as a positive GCT and normal OGTT results. GDM was defined as a positive GCT and abnormal OGTT results. The women were categorized into the following groups: (1) GCT-negative, n = 3881; (2) BGI with MNT, n = 273; (3) BGI without MNT, n = 712; and (4) GDM, n = 328. Multiple logistic analyses were used to estimate the risks of pregnancy outcomes. RESULTS: The odds ratios (95% confidence interval) for total cesareans, third- or fourth-degree perineal lacerations, gestational hypertension or preeclampsia and macrosomia were 1.24 (1.04-1.49), 1.55 (1.06-1.28), 1.78 (1.21-2.61) and 2.50 (1.28-4.91) in the BGI without MNT group compared to the GCT-negative group. There was no difference between BGI with MNT and GCT-negative groups. CONCLUSIONS: Women with BGI who did not receive MNT had increased risks of adverse pregnancy outcomes, whereas who received MNT had no different risk with GCT-negative women.

The efficacy and safety of probiotics intervention in preventing conversion of impaired glucose tolerance to diabetes: study protocol for a randomized, double-blinded, placebo controlled trial of the Probiotics Prevention Diabetes Programme (PPDP).

BACKGROUND: Alterations in intestinal microbiota correlate with risk of development of obesity and type 2 diabetes. Probiotics have been suggested to play an important role in the management of dysglycemia, although the evidence is limited. In this study, we aim to explore the efficacy and safety of probiotics intervention in preventing type 2 diabetes in Chinese patients with impaired glucose tolerance. METHODS/DESIGN: A 24-month randomized intervention is conducted from January 2014 to December 2016. The target sample size for intervention is 200 middle-aged men and women aged 30-65 year-old with impaired glucose tolerance. Participants with persistent impaired glucose tolerance were assigned to group A (tablet A) and B (tablet B) in sequential order. The participants and investigators were blinded to the assignment. The primary outcome is development of diabetes. The secondary outcome measures include body composition, biochemical variables and the safety of the probiotics. DISCUSSION: The results from this trial will provide the evidence on the efficacy and safety of probiotics administration in preventing conversion of impaired glucose tolerance to diabetes in a Chinese context. TRIAL REGISTRATION: ChiCTRTRC13004024.

Dietary ribonucleic acid suppresses inflammation of adipose tissue and improves glucose intolerance that is mediated by immune cells in C57BL/6 mice fed a high-fat diet.

Recent evidence suggests that immune cells play an important role in differentiation of inflammatory macrophages in adipose tissue, which contributes to systemic chronic inflammation. Dietary ribonucleic acid (RNA) has been shown to modulate immune function. We hypothesized that RNA affects immune cell function in adipose tissue and then improves inflammatory response in adipose tissue. C57/BL6 mice and recombination activating gene-1 (RAG-1) knockout mice on a C57BL/6 mice background were fed a high-fat diet containing 1% RNA for 12 wk. An oral glucose tolerance test was performed. Supplementation of dietary RNA in C57BL/6 mice fed a high-fat diet resulted in a smaller area under the curve (AUC) after oral glucose administration than that for control mice. The mRNA expression levels of inflammation-related cytokines in adipose tissue and serum interleukin-6 levels were reduced by dietary RNA supplementation. Interestingly, reduction of the AUC value by RNA supplementation was abolished in T and B cell-deficient RAG-1 knockout mice. These results indicate that RNA improves inflammation in adipose tissue and reduces the AUC value following oral glucose administration in a T and B cell-dependent manner.

Blueberries improve glucose tolerance without altering body composition in obese postmenopausal mice.

OBJECTIVE: Metabolic syndrome (MetS) risk increases significantly during menopause and remains elevated postmenopause. Several botanicals, including blueberries (BB), have been shown to delay MetS progression, but few studies have been conducted in postmenopausal animal models. Here, the effects of BB supplementation on obese postmenopausal mice using a chemically induced menopause model were examined. METHODS: After induction of menopause, mice were fed a high-fat diet or the same diet supplemented with 4% BB powder for 12 weeks. Body weight and body composition were measured, and mice were subjected to glucose and insulin tolerance tests. Serum triglycerides and adiponectin were measured, and liver histology and hepatic gene expression were assessed. RESULTS: Menopausal and BB-supplemented mice had significantly higher body weights and fat mass than control mice, while menopausal mice had impaired glucose tolerance and higher serum triglycerides when compared with control and BB-supplemented mice. Menopausal mice also had hepatic steatosis that was prevented by BB supplementation and correlated with expression of genes involved in hepatic fatty acid oxidation. CONCLUSIONS: BB supplementation prevents the glucose intolerance and hepatic steatosis that occur in obese postmenopausal mice, and these effects are independent of body weight.

Dietary α-lactalbumin supplementation alleviates normocaloric western diet-induced glucose intolerance in Göttingen minipigs.

OBJECTIVE: The pandemic of obesity in Western countries is mainly due to the high-fat, high-energy diet prevailing there. Obesity-associated metabolic disorders are the consequence of fat mass increase leading to altered adipokine secretion, hyperlipemia, oxidant stress, low-grade inflammation, and eventually glucose intolerance. Yet not all people consuming a Western diet become obese, and the question is raised whether these people are also at risk of developing metabolic disorders. METHODS: Glucose tolerance, lipid profile, and oxidant and inflammation status were investigated longitudinally in lean Göttingen minipigs receiving for 16 weeks either a normal diet (ND), a Western diet (WD), or a Western diet supplemented with a whey protein isolate (WPI) rich in α-lactalbumin known to improve glucose tolerance. ND and WD were supplied isoenergetically. RESULTS: Lean minipigs fed WD displayed glucose intolerance and altered lipid profile after 6 weeks of diet but no inflammation or oxidative stress. Supplementation with WPI alleviated glucose intolerance by improving insulin secretion, but not lipid profile. CONCLUSIONS: Western diet consumption is deleterious for glucose tolerance even in the absence of fat mass accretion, and dyslipemia is a major determinant for this metabolic dysfunction. Stimulating insulin secretion with a WPI is an effective strategy to improve glucose tolerance.

Efficacy of nutrition therapy for glucose intolerance in Japanese women diagnosed with gestational diabetes based on IADPSG criteria during early gestation.

AIMS: Among women with gestational diabetes mellitus (GDM), the aggravation of glucose intolerance during gestation differs substantially. We retrospectively investigated whether the glucose intolerance of women diagnosed with GDM during early gestation (i.e., early-onset GDM) improved in the mid-gestation under appropriate nutrition therapy. METHODS: We conducted a longitudinal analysis of glucose tolerance derived from 75-g oral glucose tolerance test (OGTT) in 41 Japanese women with early-onset GDM defined by International Association of Diabetes and Pregnancy Study Group criteria during early gestation (<20 weeks). Glucose tolerance was also evaluated in mid-gestation (24-32 weeks) and postpartum. Insulin sensitivity, insulin secretion, and ß-cell function were assessed at each period. RESULTS: The glucose tolerance in 18 of the 41 early-onset GDM patients normalized during mid-gestation with appropriate nutrition therapy, defined as GDM→NGT. These women did not require insulin therapy during their pregnancies, whereas 39.1% of women who retained GDM in mid-gestation (defined as GDM→GDM) required insulin therapy. The frequency of the postpartum development of type 2 diabetes or impaired glucose tolerance was significantly lower (5.6% vs. 39.1% in GDM→NGT vs. GDM→GDM, p=0.03). Primiparity was determined as a predictive factor whether or not glucose intolerance was improved by nutrition therapy, but results of plasma glucose levels from OGTT at early gestation were not, in a multivariate logistic regression analysis. CONCLUSIONS: Appropriate nutrition therapy for women with early-onset GDM seemed effective to improve glucose tolerance during pregnancy. OGTT retesting during their mid-gestation seemed effective for predicting the appropriate treatment after the second trimester.