The oral disposition index calculated from a meal tolerance test is a crucial indicator for evaluating differential normalization of postprandial glucose and triglyceride excursions in morbidly obese patients after laparoscopic sleeve gastrectomy.

To determine the normalization of postprandial blood glucose (PG) and triglyceride (TG) excursions in 30 morbidly obese patients with or without diabetes mellitus (DM) 1-year after they underwent a laparoscopic sleeve gastrectomy (LSG) vs. their pre-surgery data, we administered the 75-g oral glucose tolerance test (OGTT) and a meal tolerance test (MTT) using a 75-g glucose-equivalent carbohydrate- and fat-containing meal. The results were as follows; (i) Postoperative body-weight reduction was associated with DM remission and reduced multiple cardiometabolic risks. (ii) OGTT data showing postprandial hyper-insulinemic hypoglycemia in many post-surgery patients were associated with overdiagnosis of improved glucose tolerance. However, postoperative MTT data without hypoglycemia showed no improvement in the glucose tolerance vs. pre-surgery data. (iii) The disposition index (DI) i.e., [Matsuda index] × (Glucose-induced insulin secretion) was progressively worsened from normal glucose tolerance to DM patients after LSG. These post-surgery DI values measured by the MTT were correlated with 2h-plasma glucose levels and were not normalized in DM patients. (iv) The baseline, 2h-TG, and an increase in 2h-TG values above baseline were correlated with the insulin resistance index, DI, or HbA1c; These TG values were normalized post-LSG. In conclusion, the glucose tolerance curve measured by the MTT was not normalized in T2DM patients, which was associated with impaired normalization of the DI values in those patients 1-year after the LSG. However, the baseline TG and a fat-induced 2h-TG values were normalized postoperatively. The MTT can be used to assess normalization in postprandial glucose and TG excursions after LSG.

Effects of a new 75 g glucose- and high fat-containing cookie meal test on postprandial glucose and triglyceride excursions in morbidly obese patients.

A new meal tolerance test (MTT) using a 75 g glucose- and high fat-containing meal was applied to classify glucose intolerance in morbidly obese patients. According to the MTT data, the concordance rate of diagnosis was 82.5% compared to the 75 g oral glucose tolerance test (OGTT) in patients with normal glucose tolerance (NGT, n = 40). In the NGT patients, the insulinogenic index (r = 0.833), Matsuda index (r = 0.752), and disposition index (r = 0.845) calculated from the MTT data were each significantly (p < 0.001) correlated with those derived from the OGTT data. However, in patients with impaired glucose tolerance (IGT, n = 23) or diabetes mellitus (DM, n = 17), the postprandial glucose levels post-MTT were significantly lower than those post-OGTT, without increases in the postprandial insulin levels post-MTT. Thus, the severity of glucose intolerance measured by the MTT was milder than that indicated by the OGTT. Plasma levels of both glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) were increased at the postprandial state, but only the GIP levels post-MTT were significantly higher than those post-OGTT. The enhancement of glucose disposal rates in patients with NGT or IGT after the MTT was associated with increased GIP levels. The postprandial hypertriglyceridemia induced by the MTT was associated with insulin resistance, but it was not associated with the impaired insulinogenic index or the disposition index. These results indicate that the new MTT is clinically useful to evaluate both abnormal glucose and triglyceride excursions caused by abnormal insulin sensitivity and secretions of insulin and gut hormones in morbidly obese patients.

Preserving ß-cell function is the major determinant of diabetes remission following laparoscopic sleeve gastrectomy in Japanese obese diabetic patients.

Laparoscopic sleeve gastrectomy has been proven effective in treating obesity-associated type 2 diabetes mellitus (T2DM). However, reports of the effect of laparoscopic sleeve gastrectomy on glucose metabolism in Japanese obese patients with T2DM are rare. The aim of this study was to evaluate the effects of laparoscopic sleeve gastrectomy on glucose tolerance in Japanese obese patients with T2DM, and to analyze factors influencing diabetes remission after surgery. This was a retrospective analysis of data for 24 consecutive patients with T2DM who underwent laparoscopic sleeve gastrectomy. We investigated weight loss and its impact on T2DM 1 year postoperatively. We also compared baseline characteristics and postoperative factors between patients who achieved diabetes remission and patients without remission. Mean body weight loss and percent total weight loss were 23.9 kg and 23.3%, respectively. Mean hemoglobin A1c levels dropped from 7.3 ± 0.3% to 6.1 ± 0.2%, and 18 patients (75%) achieved diabetes remission 1 year postoperatively. Patients achieving remission had significantly lower hemoglobin A1c levels (p = 0.026), higher fasting C-peptide values (p < 0.001), shorter diabetes duration (p < 0.001), lower insulin requirement (p = 0.002), and higher area under the insulin response curve (p < 0.001) and insulinogenic index (p < 0.001) during oral glucose tolerance testing. In conclusion, laparoscopic sleeve gastrectomy is an effective treatment for Japanese obese patients with T2DM. Preserving insulin secretion is the major determinant of diabetes remission.

Lack of O-GlcNAcylation enhances exercise-dependent glucose utilization potentially through AMP-activated protein kinase activation in skeletal muscle.

O-GlcNAcylation is a post-translational modification that is characterized by the addition of N-acetylglucosamine (GlcNAc) to proteins by O-GlcNAc transferase (Ogt). The degree of O-GlcNAcylation is thought to be associated with glucotoxicity and diabetic complications, because GlcNAc is produced by a branch of the glycolytic pathway. However, its role in skeletal muscle has not been fully elucidated. In this study, we created skeletal muscle-specific Ogt knockout (Ogt-MKO) mice and analyzed their glucose metabolism. During an intraperitoneal glucose tolerance test, blood glucose was slightly lower in Ogt-MKO mice than in control Ogt-flox mice. High fat diet-induced obesity and insulin resistance were reversed in Ogt-MKO mice. In addition, 12-month-old Ogt-MKO mice had lower adipose and body mass. A single bout of exercise significantly reduced blood glucose in Ogt-MKO mice, probably because of higher AMP-activated protein kinase α (AMPKα) protein expression. Furthermore, intraperitoneal injection of 5-aminoimidazole-4-carboxamide ribonucleotide, an AMPK activator, resulted in a more marked decrease in blood glucose levels in Ogt-MKO mice than in controls. Finally, Ogt knockdown by siRNA in C2C12 myotubes significantly increased protein expression of AMPKα, glucose uptake and oxidation. In conclusion, loss of O-GlcNAcylation facilitates glucose utilization in skeletal muscle, potentially through AMPK activation. The inhibition of O-GlcNAcylation in skeletal muscle may have an anti-diabetic effect, through an enhancement of glucose utilization during exercise.

Diverse metabolic effects of O-GlcNAcylation in the pancreas but limited effects in insulin-sensitive organs in mice.

AIMS/HYPOTHESIS: O-GlcNAcylation is characterised by the addition of N-acetylglucosamine to various proteins by O-GlcNAc transferase (OGT) and serves in sensing intracellular nutrients by modulating various cellular processes. Although it has been speculated that O-GlcNAcylation is associated with glucose metabolism, its exact role in whole body glucose metabolism has not been fully elucidated. Here, we investigated whether loss of O-GlcNAcylation globally and in specific organs affected glucose metabolism in mammals under physiological conditions. METHODS: Tamoxifen-inducible global Ogt-knockout (Ogt-KO) mice were generated by crossbreeding Ogt-flox mice with R26-Cre-ERT2 mice. Liver, skeletal muscle, adipose tissue and pancreatic beta cell-specific Ogt-KO mice were generated by crossbreeding Ogt-flox mice with Alb-Cre, Mlc1f-Cre, Adipoq-Cre and Pdx1 PB-CreER™ mice, respectively. Glucose metabolism was evaluated by i.p. glucose and insulin tolerance tests. RESULTS: Tamoxifen-inducible global Ogt-KO mice exhibited a lethal phenotype from 4 weeks post injection, suggesting that O-GlcNAcylation is essential for survival in adult mice. Tissue-specific Ogt deletion from insulin-sensitive organs, including liver, skeletal muscle and adipose tissue, had little impact on glucose metabolism under physiological conditions. However, pancreatic beta cell-specific Ogt-KO mice displayed transient hypoglycaemia (Ogt-flox 5.46 ± 0.41 vs Ogt-ßKO 3.88 ± 0.26 mmol/l) associated with about twofold higher insulin secretion and accelerated adiposity, followed by subsequent hyperglycaemia (Ogt-flox 6.34 ± 0.32 vs Ogt-ßKO 26.4 ± 2.37 mmol/l) with insulin depletion accompanied by beta cell apoptosis. CONCLUSIONS/INTERPRETATION: These findings suggest that O-GlcNAcylation has little effect on glucose metabolism in insulin-sensitive tissues but plays a crucial role in pancreatic beta cell function and survival under physiological conditions. Our results provide novel insight into O-GlcNAc biology and physiology in glucose metabolism.

O-linked ß-N-acetylglucosamine modification of proteins is essential for foot process maturation and survival in podocytes.

BACKGROUND: O-linked ß- N -acetylglucosamine modification O-GlcNAcylation) is a post-translational modification of intracellular proteins, serving as a nutrient sensor. Growing evidence has demonstrated its physiological and pathological importance in various mammalian tissues. This study examined the physiological role of O-GlcNAcylation in podocyte function and development. METHODS: O-GlcNAc transferase (Ogt) is a critical enzyme for O-GlcNAcylation and resides on the X chromosome. To abrogate O-GlcNAcylation in podocytes, we generated congenital and tamoxifen (TM)-inducible podocyte-specific Ogt knockout mice (Podo-Ogt y/- and TM-Podo-Ogt y/- , respectively) and analyzed their renal phenotypes. RESULTS: Podo-Ogt y/- mice showed normal podocyte morphology at birth. However, they developed albuminuria at 8 weeks of age, increasing progressively until age 32 weeks. Glomerular sclerosis, proteinuria-related tubulointerstitial lesions and markedly altered podocyte foot processes, with decreased podocin expression, were observed histologically in 32-week-old Podo-Ogt y/- mice. Next, we induced adult-onset deletion of the Ogt gene in podocytes by TM injection in 8-week-old TM-Podo-Ogt y/- mice. In contrast to Podo-Ogt y/- mice, the induced TM-Podo-Ogt y/- mice did not develop albuminuria or podocyte damage, suggesting a need for O-GlcNAcylation to form mature foot processes after birth. To test this possibility, 3-week-old Podo-Ogt y/- mice were treated with Bis-T-23, which stimulates actin-dependent dynamin oligomerization, actin polymerization and subsequent foot process elongation in podocytes. Albuminuria and podocyte damage in 16-week-old Podo-Ogt y/- mice were prevented by Bis-T-23 treatment. CONCLUSIONS: O-GlcNAcylation is necessary for maturation of podocyte foot processes, particularly after birth. Our study provided new insights into podocyte biology and O-GlcNAcylation.

Acute Effect of Metformin on Postprandial Hypertriglyceridemia through Delayed Gastric Emptying.

Postprandial hypertriglyceridemia is a potential target for cardiovascular disease prevention in patients with diabetic dyslipidemia. Metformin has been reported to reduce plasma triglyceride concentrations in the postprandial states. However, little is known about the mechanisms underlying the triglyceride-lowering effect of metformin. Here, we examined the effects of metformin on lipid metabolism after olive oil-loading in 129S mice fed a high fat diet for three weeks. Metformin administration (250 mg/kg) for one week decreased postprandial plasma triglycerides. Pre-administration (250 mg/kg) of metformin resulted in a stronger triglyceride-lowering effect (approximately 45% lower area under the curve) than post-administration. A single administration (250 mg/kg) of metformin lowered plasma postprandial triglycerides comparably to administration for one week, suggesting an acute effect of metformin on postprandial hypertriglyceridemia. To explore whole body lipid metabolism after fat-loading, stomach size, fat absorption in the intestine, and fat oxidation (13C/12C ratio in expired CO2 after administration of glyceryl-1-13C tripalmitate) were measured with and without metformin (250 mg/kg) pre-treatment. In metformin-treated mice, larger stomach size, lower fat oxidation, and no change in lipid absorption were observed. In conclusion, metformin administration before fat loading reduced postprandial hypertriglyceridemia, most likely by delaying gastric emptying.

4-Hydroxy hexenal derived from dietary n-3 polyunsaturated fatty acids induces anti-oxidative enzyme heme oxygenase-1 in multiple organs.

It has recently been reported that expression of heme oxygenase-1 (HO-1) plays a protective role against many diseases. Furthermore, n-3 polyunsaturated fatty acids (PUFAs) were shown to induce HO-1 expression in several cells in vitro, and in a few cases also in vivo. However, very few reports have demonstrated that n-3 PUFAs induce HO-1 in vivo. In this study, we examined the effect of fish-oil dietary supplementation on the distribution of fatty acids and their peroxidative metabolites and on the expression of HO-1 in multiple tissues (liver, kidney, heart, lung, spleen, intestine, skeletal muscle, white adipose, brown adipose, brain, aorta, and plasma) of C57BL/6 mice. Mice were divided into 4 groups, and fed a control, safflower-oil, and fish-oil diet for 3 weeks. One group was fed a fish-oil diet for just 1 week. The concentration of fatty acids, 4-hydroxy hexenal (4-HHE), and 4-hydroxy nonenal (4-HNE), and the expression of HO-1 mRNA were measured in the same tissues. We found that the concentration of 4-HHE (a product of n-3 PUFAs peroxidation) and expression of HO-1 mRNA were significantly increased after fish-oil treatment in most tissues. In addition, these increases were paralleled by an increase in the level of docosahexaenoic acid (DHA) but not eicosapentaenoic acid (EPA) in each tissue. These results are consistent with our previous results showing that DHA induces HO-1 expression through 4-HHE in vascular endothelial cells. In conclusion, we hypothesize that the HO-1-mediated protective effect of the fish oil diet may be through production of 4-HHE from DHA but not EPA in various tissues.

Ezetimibe prevents hepatic steatosis induced by a high-fat but not a high-fructose diet.

Nonalcoholic fatty liver disease is the most frequent liver disease. Ezetimibe, an inhibitor of intestinal cholesterol absorption, has been reported to ameliorate hepatic steatosis in human and animal models. To explore how ezetimibe reduces hepatic steatosis, we investigated the effects of ezetimibe on the expression of lipogenic enzymes and intestinal lipid metabolism in mice fed a high-fat or a high-fructose diet. CBA/JN mice were fed a high-fat diet or a high-fructose diet for 8 wk with or without ezetimibe. High-fat diet induced hepatic steatosis accompanied by hyperinsulinemia. Treatment with ezetimibe reduced hepatic steatosis, insulin levels, and glucose production from pyruvate in mice fed the high-fat diet, suggesting a reduction of insulin resistance in the liver. In the intestinal analysis, ezetimibe reduced the expression of fatty acid transfer protein-4 and apoB-48 in mice fed the high-fat diet. However, treatment with ezetimibe did not prevent hepatic steatosis, hyperinsulinemia, and intestinal apoB-48 expression in mice fed the high-fructose diet. Ezetimibe decreased liver X receptor-α binding to the sterol regulatory element-binding protein-1c promoter but not expression of carbohydrate response element-binding protein and fatty acid synthase in mice fed the high-fructose diet, suggesting that ezetimibe did not reduce hepatic lipogenesis induced by the high-fructose diet. Elevation of hepatic and intestinal lipogenesis in mice fed a high-fructose diet may partly explain the differences in the effect of ezetimibe.

Omega-3 polyunsaturated fatty acid has an anti-oxidant effect via the Nrf-2/HO-1 pathway in 3T3-L1 adipocytes.

Oxidative stress is produced in adipose tissue of obese subjects and has been associated with obesity-related disorders. Recent studies have shown that omega-3 polyunsaturated fatty acid (ω3-PUFA) has beneficial effects in preventing atherosclerotic diseases and insulin resistance in adipose tissue. However, the role of ω3-PUFA on adipocytes has not been elucidated. In this study, 3T3-L1 adipocytes were treated with ω3-PUFA and its metabolites, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), or 4-hydroxy hexenal (4-HHE). ω3-PUFA and its metabolites dose-dependently increased mRNA and protein levels of the anti-oxidative enzyme, heme oxygenase-1 (HO-1); whereas no changes in the well-known anti-oxidant molecules, superoxide dismutase, catalase, and glutathione peroxidase, were observed. Knockdown of nuclear factor erythroid 2-related factor 2 (Nrf-2) significantly reduced EPA, DHA or 4-HHE-induced HO-1 mRNA and protein expression. Also, pretreatment with ω3-PUFA prevented H(2)O(2)-induced cytotoxicity in a HO-1 dependent manner. In conclusion, treatment with EPA and DHA induced HO-1 through the activation of Nrf-2 and prevented oxidative stress in 3T3-L1 adipocytes. This anti-oxidant defense may be of high therapeutic value for clinical conditions associated with systemic oxidative stress.

Autophagy regulates inflammation in adipocytes.

Autophagy is an essential process for both the maintenance and the survival of cells, with homeostatic low levels of autophagy being critical for intracellular organelles and proteins. In insulin resistant adipocytes, various dysfunctional/damaged molecules, organelles, proteins, and end-products accumulate. However, the role of autophagy (in particular, whether autophagy is activated or not) is poorly understood. In this study we found that in adipose tissue of insulin resistant mice and hypertrophic 3T3-L1 adipocytes autophagy was suppressed. Also in hypertrophic adipocytes, autophagy-related gene expression, such as LAMP1, LAMP2, and Atg5 was reduced, whereas gene expression in the inflammatory-related genes, such as MCP-1, IL-6, and IL-1ß was increased. To find out whether suppressed autophagy was linked to inflammation we used the autophagy inhibitor, 3-methyladenine, to inhibit autophagy. Our results suggest that such inhibition leads to an increase in inflammatory gene expression and causes endoplasmic reticulum (ER) stress (which can be attenuated by treatment with the ER stress inhibitor, Tauroursodeoxycholic Acid). Conversely, the levels of inflammatory gene expression were reduced by the activation of autophagy or by the inhibition of ER stress. The results indicate that the suppression of autophagy increases inflammatory responses via ER stress, and also defines a novel role of autophagy as an important regulator of adipocyte inflammation in systemic insulin resistance.

Blocking O-linked GlcNAc cycling in Drosophila insulin-producing cells perturbs glucose-insulin homeostasis.

A dynamic cycle of O-linked GlcNAc (O-GlcNAc) addition and removal is catalyzed by O-GlcNAc transferase and O-GlcNAcase, respectively, in a process that serves as the final step in a nutrient-driven "hexosamine-signaling pathway." Evidence points to a role for O-GlcNAc cycling in diabetes and insulin resistance. We have used Drosophila melanogaster to determine whether O-GlcNAc metabolism plays a role in modulating Drosophila insulin-like peptide (dilp) production and insulin signaling. We employed transgenesis to either overexpress or knock down Drosophila Ogt(sxc) and Oga in insulin-producing cells (IPCs) or fat bodies using the GAL4-UAS system. Knockdown of Ogt decreased Dilp2, Dilp3, and Dilp5 production, with reduced body size and decreased phosphorylation of Akt in vivo. In contrast, knockdown of Oga increased Dilp2, Dilp3, and Dilp5 production, increased body size, and enhanced phosphorylation of Akt in vivo. However, knockdown of either Ogt(sxc) or Oga in the IPCs increased the hemolymph carbohydrate concentration. Furthermore, phosphorylation of Akt stimulated by extraneous insulin in an ex vivo cultured fat body of third instar larvae was diminished in strains subjected to IPC knockdown of Ogt or Oga. Knockdown of O-GlcNAc cycling enzymes in the fat body dramatically reduced neutral lipid stores. These results demonstrate that altered O-GlcNAc cycling in Drosophila IPCs modulates insulin production and influences the insulin responsiveness of peripheral tissues. The observed phenotypes in O-GlcNAc cycling mimic pancreatic ß-cell dysfunction and glucose toxicity related to sustained hyperglycemia in mammals.

A Prospective, Open-Label Short-Term Pilot Study on Modification of the Skin Hydration Status During Treatment With a Sodium-Glucose Cotransporter-2 Inhibitor.

INTRODUCTION: Various types of skin lesions with pruritus have been reported in participants of Asian clinical trials on sodium-glucose cotransporter-2 (SGLT2) inhibitors. The aim of this study was to determine whether the diuretic effect of a SGLT2 inhibitor could modify skin hydration status in patients with type 2 diabetes mellitus. METHODS: A prospective, short-term, open-label, two-parallel-arm, pilot study was conducted. Eligible patients were assigned to either a SGLT2 inhibitor (50 mg ipragliflozin once daily) group or to a dipeptidyl peptidase-4 inhibitor (50 mg sitagliptin once daily) group (control). The biophysical characteristics of the skin were measured and blood chemistry tests were run in all participants 1 day prior to medication initiation (pre-treatment values) and 14 days thereafter (post-treatment values). RESULTS: Fourteen patients were enrolled in the study, of whom eight were in the ipragliflozin group and six in the sitagliptin group. Compared to the pre-treatment values, the glycated hemoglobin (HbA1c) levels were slightly but significantly reduced in the ipragliflozin group (p = 0.02), but the changes in HbA1c from the pre-treatment to post-treatment time points did not significantly differ between the two treatment groups. Serum 3-hydroxy butyrate levels were significantly higher in the ipragliflozin group than in the sitagliptin group (p < 0.02). Neither electrical capacitance nor electrical conductance of the stratum corneum (SC), parameters that reflect skin water content, was reduced by 14 days of ipragliflozin treatment; similarly, no changes in these parameters were found in the sitagliptin control group. There was also no difference in the changes in water barrier function of the SC between the two treatment groups. There was a significant linear correlation (p < 0.01) in skin water content at pre-treatment and that 14 days after treatment with each drug, respectively. CONCLUSION: Ipragliflozin treatment for 14 days did not significantly affect the skin hydration status in patients with well-controlled type 2 diabetes mellitus.

[Musculoskeletal rehabilitation and bone. Development of Simulator (Jouba) for horse riding therapy and utility for the aged].

Horseback riding therapy is popularly used as one of the physiotherapy in Europe. Dr. Kimura hit upon Horseback Riding Robot, which can precisely simulate horseback motion ; as a result, he has developed and completed the Horseback Riding Robot, which can be worked by six motors. The Horseback Riding Robot, however, is very expensive. For that reason we have decided to turn over a new leaf and have developed a home machine by realizing one motor type. We proved the muscle strength trainings by use of Horse Riding Robot and a home machine, unlike a existing monotonous and boring muscle training, to be worthwhile and effective.

Efficacy of metformin on postprandial plasma triglyceride concentration by administration timing in patients with type 2 diabetes mellitus: A randomized cross-over pilot study.

AIMS/INTRODUCTION: Preprandial metformin administration significantly reduces postprandial plasma triglyceride levels in animal studies by reducing intestinal absorption through delayed gastric emptying. However, this effect has not been shown in a clinical study. Therefore, we planned to investigate the efficacy of preprandial metformin administration on postprandial hypertriglyceridemia and the related gastrointestinal effects in patients with type 2 diabetes mellitus. MATERIALS AND METHODS: A total of 11 patients taking single-dose metformin at 500-1,000 mg, with non-fasting plasma triglyceride levels of 150-1,000 mg/dL, were recruited at a single university hospital. The difference between preprandial and postprandial metformin administration on postprandial hypertriglyceridemia was examined by a meal test. The gastrointestinal effects of metformin, including stomach heaviness, heartburn and satiety, were also assessed using a visual analog scale. RESULTS: The mean bodyweight of patients was 80.6 kg (body mass index 27.9 kg/m2 ), and the mean non-fasting plasma triglyceride level was 275.9 ± 57.0 mg/dL. The area under the curve of triglyceride during the meal test was significantly lower in the preprandial protocol than in the postprandial protocol (P < 0.05). Compared with postprandial administration, preprandial administration of metformin increased satiety (P = 0.036) without stomach heaviness or heartburn. CONCLUSIONS: Preprandial metformin administration significantly reduced plasma triglyceride level during meal testing without marked exacerbation of gastrointestinal adverse effects. The present results suggest that a simple change in the timing of metformin administration represents a novel approach for enhancing triglyceride-lowering strategies in patients with type 2 diabetes mellitus and postprandial hypertriglyceridemia.

Ipragliflozin, a sodium-glucose cotransporter 2 inhibitor, reduces bodyweight and fat mass, but not muscle mass, in Japanese type 2 diabetes patients treated with insulin: A randomized clinical trial.

AIMS/INTRODUCTION: Sodium-glucose cotransporter 2 inhibitors reduce bodyweight (BW) by creating a negative energy balance. Previous reports have suggested that this BW reduction is mainly loss of body fat and that ~20% of the reduction is lean mass. However, the effects of sodium-glucose cotransporter 2 inhibitors on BW and body composition remain unclear. We examined these effects in Japanese patients with type 2 diabetes mellitus treated with insulin. MATERIALS AND METHODS: In this open-label, randomized controlled trial, 49 overweight patients (body mass index ≥23 kg/m2 ) with inadequate glycemic control (hemoglobin A1c >7.0%) receiving insulin treatment were randomly assigned to receive add-on ipragliflozin or no additional treatment (control group). Patients were followed for 24 weeks. The goal for all patients was to achieve glycated hemoglobin <7.0% without hypoglycemia. The primary end-point was a change in BW from baseline to week 24. Body composition was assessed with dual-energy X-ray absorptiometry and bioelectrical impedance analysis. RESULTS: BW change was significantly larger in the ipragliflozin group than in the control group (-2.78 vs -0.22 kg, P < 0.0001). Total fat mass was reduced evenly in the arms, lower limbs and trunk in the ipragliflozin group. Total muscle mass and bone mineral content were maintained, but muscle mass in the arms might have been affected by ipragliflozin treatment. CONCLUSIONS: Ipragliflozin treatment for 24 weeks resulted in reduced BW, mainly from fat mass loss. Muscle mass and bone mineral content were maintained. Further study is necessary to elucidate the long-term effects of ipragliflozin.

MiR-494-3p regulates mitochondrial biogenesis and thermogenesis through PGC1-α signalling in beige adipocytes.

Mitochondria are critical in heat generation in brown and beige adipocytes. Mitochondrial number and function are regulated in response to external stimuli, such as cold exposure and ß3 adrenergic receptor agonist. However, the molecular mechanisms regulating mitochondrial biogenesis during browning, especially by microRNAs, remain unknown. We investigated the role of miR-494-3p in mitochondrial biogenesis during adipogenesis and browning. Intermittent mild cold exposure of mice induced PPARγ coactivator1-α (PGC1-α) and mitochondrial TFAM, PDH, and ANT1/2 expression along with uncoupling protein-1 (Ucp1) in inguinal white adipose tissue (iWAT). miR-494-3p levels were significantly downregulated in iWAT upon cold exposure (p < 0.05). miR-494-3p overexpression substantially reduced PGC1-α expression and its downstream targets TFAM, PDH and MTCO1 in 3T3-L1 white and beige adipocytes (p < 0.05). miR-494-3p inhibition in 3T3-L1 white adipocytes resulted in increased PDH (p < 0.05). PGC1-α, TFAM and Ucp1 mRNA levels were robustly downregulated by miR-494-3p overexpression in 3T3-L1 beige adipocytes, along with strongly decreased oxygen consumption rate. PGC1-α and Ucp1 proteins were downregulated by miR-494-3p in primary beige cells (p < 0.05). Luciferase assays confirmed PGC1-α as a direct gene target of miR-494-3p. Our findings demonstrate that decreased miR-494-3p expression during browning regulates mitochondrial biogenesis and thermogenesis through PGC1-α.

Improved glucose metabolism by Eragrostis tef potentially through beige adipocyte formation and attenuating adipose tissue inflammation.

BACKGROUND: Teff is a staple food in Ethiopia that is rich in dietary fiber. Although gaining popularity in Western countries because it is gluten-free, the effects of teff on glucose metabolism remain unknown. AIM: To evaluate the effects of teff on body weight and glucose metabolism compared with an isocaloric diet containing wheat. RESULTS: Mice fed teff weighed approximately 13% less than mice fed wheat (p < 0.05). The teff-based diet improved glucose tolerance compared with the wheat group with normal chow but not with a high-fat diet. Reduced adipose inflammation characterized by lower expression of TNFα, Mcp1, and CD11c, together with higher levels of cecal short chain fatty acids such as acetate, compared with the control diet containing wheat after 14 weeks of dietary treatment. In addition, beige adipocyte formation, characterized by increased expression of Ucp-1 (~7-fold) and Cidea (~3-fold), was observed in the teff groups compared with the wheat group. Moreover, a body-weight matched experiment revealed that teff improved glucose tolerance in a manner independent of body weight reduction after 6 weeks of dietary treatment. Enhanced beige adipocyte formation without improved adipose inflammation in a body-weight matched experiment suggests that the improved glucose metabolism was a consequence of beige adipocyte formation, but not solely through adipose inflammation. However, these differences between teff- and wheat-containing diets were not observed in the high-fat diet group. CONCLUSIONS: Teff improved glucose tolerance likely by promoting beige adipocyte formation and improved adipose inflammation.

Impact of obesity on annual medical expenditures and diabetes care in Japanese patients with type 2 diabetes mellitus.

AIMS/INTRODUCTION: Diabetes and obesity are important health and economic concerns. We investigated the influence of obesity on diabetes control, the annual medical expenditures and medications in Japanese patients with type 2 diabetes who were relatively lean in comparison with those in Western countries. MATERIALS AND METHODS: A total of 402 Japanese patients with type 2 diabetes were enrolled and their annual medical expenditures investigated. Obesity was defined as body mass index ≥25 kg/m2 , according to the obesity classifications from the Japan Society for the Study of Obesity. RESULTS: A total of 165 patients (41.0%) were classified as obese. The obese group was younger, had poor glycemic control and higher frequency of hypertension than the non-obese group. The median total annual medical expenditures for all participants was ¥269,333 (interquartile range ¥169,664-437,437), which was equivalent to approximately $US2,450. The annual medical expenditure was significantly higher in patients with obesity than in non-obese patients (P < 0.001). This difference was mainly attributed to the annual expenditures for medication and hospitalization. In particular, the medication expenditures and the average number of drug classes for hyperglycemia and hypertension were significantly higher in the obese group. CONCLUSIONS: Japanese patients with type 2 diabetes and obesity had higher annual medical expenditures and a larger number of medications, but their diabetes control care was insufficient in comparison with those without obesity. Further studies are required to assess the effect of reducing bodyweight on diabetes control and costs.

RBMX is a novel hepatic transcriptional regulator of SREBP-1c gene response to high-fructose diet.

In rodents a high-fructose diet induces metabolic derangements similar to those in metabolic syndrome. Previously we suggested that in mouse liver an unidentified nuclear protein binding to the sterol regulatory element (SRE)-binding protein-1c (SREBP-1c) promoter region plays a key role for the response to high-fructose diet. Here, using MALDI-TOF MASS technique, we identified an X-chromosome-linked RNA binding motif protein (RBMX) as a new candidate molecule. In electrophoretic mobility shift assay, anti-RBMX antibody displaced the bands induced by fructose-feeding. Overexpression or suppression of RBMX on rat hepatoma cells regulated the SREBP-1c promoter activity. RBMX may control SREBP-1c expression in mouse liver in response to high-fructose diet.