Empagliflozin versus sitagliptin for ameliorating intrahepatic lipid content and tissue-specific insulin sensitivity in patients with early-stage type 2 diabetes with non-alcoholic fatty liver disease: A prospective randomized study.

AIM: To compare the effects of sodium-glucose co-transporter-2 (SGLT2) inhibitors and dipeptidyl peptidase-4 inhibitors on ectopic fat accumulation and tissue-specific insulin sensitivity. MATERIALS AND METHODS: This randomized controlled trial enrolled 44 patients with type 2 diabetes (T2D) and non-alcoholic fatty liver disease (NAFLD). They were randomly assigned to receive either empagliflozin 10 mg/day or sitagliptin 100 mg/day for 12 weeks. The primary endpoint was the change in intrahepatic lipid content (IHL) measured using proton magnetic resonance spectroscopy (1 H-MRS). The secondary endpoints included intramuscular and extramuscular lipid content seen in 1 H-MRS, body composition seen through dual-energy X-ray absorptiometry and tissue-specific insulin sensitivity shown through hyperinsulinaemic-euglycaemic clamp using stable isotopic glucose. Liver biopsy samples were pathologically evaluated at baseline. RESULTS: At baseline, the mean duration of diabetes, HbA1c level and IHL were 3.7 years, 7.2% and 20.9%, respectively. The median NAFLD activity score was 3.0. IHL was significantly more decreased in the empagliflozin group than that in the sitagliptin group (between-group difference was -5.2% ± 1.1% and -1.9% ± 1.2%, respectively, (95% confidence interval); -3.3 (-6.5, -0.1), P = .044). However, there were no significant between-group differences in the change of insulin sensitivity in the liver, muscle or adipose tissues. Interestingly, hepatic insulin sensitivity was significantly increased only in the empagliflozin group and was significantly negatively associated with the change in IHL. CONCLUSIONS: Empagliflozin significantly improves hepatic steatosis compared with sitagliptin, and this may protect against subsequent hepatic insulin resistance. Early administration of SGLT2 inhibitors is preferable for T2D patients with NAFLD.

Comparison of the effects of sitagliptin and dapagliflozin on time in range in Japanese patients with type 2 diabetes stratified by body mass index: A sub-analysis of the DIVERSITY-CVR study.

AIMS: To compare the effects of baseline background characteristics in patients treated with dapagliflozin and sitagliptin in the DIVERSITY-CVR study and to analyse the time in range (TIR), a metric for glycaemic control. MATERIALS AND METHODS: This prospective, randomized, multicentre study included 340 Japanese patients with early-stage type 2 diabetes. To examine the effects of dapagliflozin and sitagliptin on glycaemic variability, we re-examined the primary endpoint (glycated haemoglobin [HbA1c] < 7.0%, body weight loss ≥ 3.0%, and avoidance of hypoglycaemia) achievement rate in participants stratified by baseline background characteristics. RESULTS: Sitagliptin was significantly superior in achieving HbA1c level <7.0% in the lower body mass index (BMI) group (71.1% vs. 43.6%; P < 0.05), with no significant differences in other subgroups. In the lower BMI group, the rate of achievement of TIR > 70% after 24-week treatment was significantly higher with sitagliptin than with dapagliflozin (91.9% vs. 69.4%; P < 0.05). In contrast, dapagliflozin was superior to sitagliptin in achieving TIR > 70% in the higher BMI group (85.7% vs. 52.9%; P < 0.01). CONCLUSION: In Japanese patients with early-stage type 2 diabetes, sitagliptin was associated with improved TIR in patients with a lower BMI. Dapagliflozin was effective in patients with a higher BMI.

A prospective randomized study comparing effects of empagliflozin to sitagliptin on cardiac fat accumulation, cardiac function, and cardiac metabolism in patients with early-stage type 2 diabetes: the ASSET study.

BACKGROUND: While the cardioprotective benefits of sodium-glucose cotransporter-2 (SGLT2) inhibitors have been established in patients with cardiovascular disease (CVD), their advantages over other anti-diabetic drugs at earlier stages remain unclear. We compared the cardioprotective effects of empagliflozin, an SGLT2 inhibitor, with those of sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, focusing on cardiac fat accumulation, cardiac function, and cardiac metabolism in patients with early-stage type 2 diabetes mellitus (T2DM) without CVD complications. METHODS: This was a prospective, randomized, open-label, blinded-endpoint, parallel-group trial that enrolled 44 Japanese patients with T2DM. The patients were randomized for 12-week administration of empagliflozin or sitagliptin. Pericardial fat accumulation and myocardial triglyceride content were evaluated by magnetic resonance imaging and proton magnetic resonance spectroscopy, respectively. Echocardiography, 123I-ß-methyl-iodophenyl pentadecanoic acid myocardial scintigraphy, and laboratory tests were performed at baseline and after the 12-week treatment period. RESULTS: The patients were middle-aged (50.3 ± 10.7 years, mean ± standard deviation) and overweight (body mass index 29.3 ± 4.9 kg/m2). They had a short diabetes duration (3.5 ± 3.2 years), HbA1c levels of 7.1 ± 0.8%, and preserved cardiac function (ejection fraction 73.8 ± 5.0%) with no vascular complications, except for one baseline case each of diabetic nephropathy and peripheral arterial disease. After the 12-week treatment, no differences from baseline were observed between the two groups regarding changes in pericardial, epicardial, and paracardial fat content; myocardial triglyceride content; cardiac function and mass; and cardiac fatty acid metabolism. However, considering cardiometabolic biomarkers, high-density lipoprotein cholesterol and ketone bodies, including ß-hydroxybutyric acid, were significantly increased, whereas uric acid, plasma glucose, plasma insulin, and homeostasis model assessment of insulin resistance were significantly lower in the empagliflozin group than in the sitagliptin group (p < 0.05). CONCLUSIONS: Although the effects on cardiac fat and function were not statistically different between the two groups, empagliflozin exhibited superior effects on cardiometabolic biomarkers, such as uric acid, high-density lipoprotein cholesterol, ketone bodies, and insulin sensitivity. Therefore, when considering the primary preventive strategies for CVD, early supplementation with SGLT2 inhibitors may be more beneficial than DPP-4 inhibitors, even in patients with early-stage T2DM without current CVD complications. CLINICAL TRIAL REGISTRATION: UMIN000026340; registered on February 28, 2017. https://upload.umin.ac.jp/cgi-open-bin/icdr_e/ctr_view.cgi?recptno=R000030257.

Efficacy of dapagliflozin versus sitagliptin on cardiometabolic risk factors in Japanese patients with type 2 diabetes: a prospective, randomized study (DIVERSITY-CVR).

BACKGROUND: Few prospective studies have compared the cardiovascular benefits of sodium-glucose cotransporter-2 (SGLT2) inhibitors and dipeptidyl peptidase 4 (DPP-4) inhibitors. We aimed to clarify the efficacy of dapagliflozin versus sitagliptin for modulating cardiometabolic risk factors including high glycated hemoglobin (HbA1c) levels, hypoglycemia, and body weight. METHODS: This prospective, randomized, open-label, blinded-endpoint, parallel-group trial enrolled 340 Japanese patients with early-stage type 2 diabetes receiving metformin alone or no glucose-lowering agents, who were randomized to receive dapagliflozin or sitagliptin for 24 weeks. The primary endpoint was the proportion of patients who achieved the composite endpoint of HbA1c level maintenance < 7.0% (53 mmol/mol), avoidance of hypoglycemia (maintenance of sensor glucose ≥ 3.0 mmol/L or ≥ 54 mg/dL), and ≥ 3.0% body weight loss from baseline. Secondary endpoints included components of the primary endpoint, other metabolic indices, and glucose variability indices measured using flash glucose monitoring. RESULTS: Clinical characteristics of patients were age, 58.1 ± 12.2 years; known duration of diabetes, 5.8 ± 6.1 years; body weight, 74.7 ± 14.2 kg; body mass index, 27.9 ± 4.1 kg/m2; and HbA1c level, 7.8 ± 0.8% at baseline. The achievement ratio of primary endpoint was significantly higher in the dapagliflozin group than in the sitagliptin group (24.4% vs. 13.8%, P < 0.05). While the rates of HbA1c level maintenance < 7.0% (53 mmol/mol) and avoidance of hypoglycemia were comparable between the groups (49.4 vs. 50.0% and 88.7 vs. 92.3% for dapagliflozin vs. sitagliptin, respectively), body weight loss of ≥ 3.0% was significantly achieved in the dapagliflozin group (54.4 vs. 19.6%, P < 0.001). Moreover, dapagliflozin was superior to sitagliptin regarding several secondary endpoints that modulate cardiometabolic risk, namely reducing fasting plasma glucose, insulin, uric acid, increasing high-density lipoprotein cholesterol, and suppressing the increase in serum creatinine and the decrease in estimated glomerular filtration rate. On the other hand, sitagliptin was superior to dapagliflozin in suppressing glucose variability. CONCLUSIONS: Compared to sitagliptin, dapagliflozin was significantly more effective at improving cardiometabolic risk factors, suggesting that SGLT2 inhibitors might be more suitable than DPP-4 inhibitors for preventing cardiovascular events in patients with early-stage but inadequately controlled type 2 diabetes. Trial registration Trial number, UMIN000028014; registered on June 30, 2017.

Efficacy of intermittent empagliflozin supplementation on dietary self-management and glycaemic control in patients with poorly controlled type 2 diabetes: A 24-week randomized controlled trial.

AIMS: To explore the effects of intermittent use of empagliflozin, a sodium-glucose co-transporter-2 inhibitor, on dietary self-management and glycaemic control in patients with inadequately controlled type 2 diabetes. MATERIALS AND METHODS: We conducted a prospective, randomized, open-label, blinded-endpoint, parallel-group, comparative clinical trial of 50 patients with type 2 diabetes, treated with no more than three oral antidiabetic drugs (glycated haemoglobin [HbA1c] ≥52 mmol/mol but <86 mmol/mol). The participants were randomized to take 10 mg/d empagliflozin either every day (regular group, n = 25) or on the day on which they considered they had overeaten (intermittent group, n = 25) for 24 weeks. We limited empagliflozin prescription to half of the required period in the intermittent group. The primary endpoint was change in HbA1c at the end of the 24-week treatment period relative to baseline. The secondary outcomes included changes in body weight, daily energy intake and diabetes treatment-related quality of life (QoL). Energy intake was assessed using a diet-specific validated questionnaire rather than actual assessments of food intake. RESULTS: The intake rate of empagliflozin was 96.7 ± 7.2% for the regular group and 45.7 ± 7.0% for the intermittent group. Interestingly, ΔHbA1c was identical in the two groups (-0.64 ± 0.19% and - 0.65 ± 0.17%, respectively). Body weight decreased (-2.72 ± 0.52 and - 1.50 ± 0.45 kg, respectively) and diabetes treatment-related QoL increased significantly from baseline in both groups. Energy intake, however, decreased significantly only in the intermittent group (-221.0 ± 108.3 kcal/d). CONCLUSIONS: Intermittent empagliflozin supplementation is a useful therapeutic option that empowers dietary self-management, improves glycaemic control and is accompanied by body weight loss and an increase in diabetes treatment-related QoL in patients with inadequately controlled type 2 diabetes.

Whole hepatic lipid volume quantification and color mapping by multi-slice and multi-point magnetic resonance imaging.

AIM: Current approaches for hepatic steatosis assess only a small point within the liver and might cause inaccuracy for longitudinal observation. We aimed to establish a reliable non-invasive method for whole hepatic lipid content evaluation. METHODS: A total of 52 patients with hepatic steatosis underwent liver biopsy. Hepatic lipid content was assessed by Dixon in-phase/out-of-phase magnetic resonance imaging and proton magnetic resonance spectroscopy. Using multi-slice and multi-point magnetic resonance imaging, we calculated the lipid intensity of every voxel throughout the liver and showed the color-mapped lipid distributions. This new analysis could also quantify the whole hepatic lipid and whole liver volumes absolutely. The diagnostic performance of hepatic lipid content between the new analysis and proton magnetic resonance spectroscopy methods was compared by receiver operating characteristic curve analysis referring to the steatosis scores of the liver biopsy. RESULTS: Areas under the receiver operating characteristic for the diagnosis of steatosis scores ≥1, ≥2, and ≥3 using magnetic resonance imaging and proton magnetic resonance spectroscopy were 0.86 (95% confidence interval [CI] 0.70-1.00) and 0.98 (95% CI 0.93-1.00), 0.94 (95% CI 0.87-1.00) and 0.93 (95% CI 0.86-1.00), and 0.95 (95% CI 0.89-1.00) and 0.97 (95% CI 0.93-1.00), respectively, showing comparable diagnostic accuracies. However, color mapping showed some inconsistencies between the methods. CONCLUSIONS: We described a non-invasive and repeatable evaluation method of whole hepatic lipid accumulation with absolute quantification and color mapping. Hepatic steatosis was accurately evaluated regardless of heterogeneous lipid accumulation. The whole hepatic lean volume, reflecting the hepatic parenchymal condition, can also be determined by this method.

Mechanisms of sleep deprivation-induced hepatic steatosis and insulin resistance in mice.

Sleep deprivation is associated with increased risk for type 2 diabetes mellitus. However, the underlying mechanisms of sleep deprivation-induced glucose intolerance remain elusive. The aim of this study was to investigate the mechanisms of sleep deprivation-induced glucose intolerance in mice with a special focus on the liver. We established a mouse model of sleep deprivation-induced glucose intolerance using C57BL/6J male mice. A single 6-h sleep deprivation by the gentle handling method under fasting condition induced glucose intolerance. Hepatic glucose production assessed by a pyruvate challenge test was significantly increased, as was hepatic triglyceride content (by 67.9%) in the sleep deprivation group, compared with freely sleeping control mice. Metabolome and microarray analyses were used to evaluate hepatic metabolites and gene expression levels and to determine the molecular mechanisms of sleep deprivation-induced hepatic steatosis. Hepatic metabolites, such as acetyl coenzyme A, 3ß-hydroxybutyric acid, and certain acylcarnitines, were significantly increased in the sleep deprivation group, suggesting increased lipid oxidation in the liver. In contrast, fasted sleep-deprived mice showed that hepatic gene expression levels of elongation of very long chain fatty acids-like 3, lipin 1, perilipin 4, perilipin 5, and acyl-CoA thioesterase 1, which are known to play lipogenic roles, were 2.7, 4.5, 3.7, 2.9, and 2.8 times, respectively, those of the fasted sleeping control group, as assessed by quantitative RT-PCR. Sleep deprivation-induced hepatic steatosis and hepatic insulin resistance seem to be mediated through upregulation of hepatic lipogenic enzymes.

Rationale and design of study of dapagliflozin versus sitagliptin treatment efficacy on prevention of cardiovascular risk factors in type 2 diabetes patients: the DIVERSITY-CVR study.

BACKGROUND: Recent studies reported that sodium glucose cotransporter 2 (SGLT2) inhibitors reduced the cardiovascular morbidity and mortality in patients with type 2 diabetes mellitus (T2DM) compared to placebo in contrast to no reduction with dipeptidyl peptidase 4 (DPP4) inhibitors. However, there are no comparative studies on the effects of SGLT2 inhibitors and DPP4 inhibitors on HbA1c, body weight and hypoglycemia as risk factors of cardiovascular diseases. The aim of the present ongoing study is to compare the effects of dapagliflozin, a SGLT2 inhibitor, with those of sitagliptin, a DPP4 inhibitor, on cardiovascular risk factors in T2DM patients with inadequate glycemic control. METHODS: The study of dapagliflozin versus sitagliptin treatment efficacy on prevention of cardiovascular risk factors in T2DM patients (DIVERSITY-CVR study) is a prospective, randomized, open-label, blinded-endpoint, parallel-group, comparative study. A total of 340 T2DM patients treated with metformin alone or with no glucose-lowering agents (hemoglobin A1c ≥ 7.0 and < 10.0%) will be randomized into the dapagliflozin group (5-10 mg/day, n = 170) and the sitagliptin group (50-100 mg/day, n = 170), and treated for 24 weeks. The primary endpoint is the rate of achieving a composite endpoint of the following three items at 24th week; (1) HbA1c < 7.0%; (2) body weight loss of ≥ 3.0% from baseline; (3) avoidance of hypoglycemia. Hypoglycemia will be monitored using the flash glucose monitoring system. The secondary outcomes include each component of the primary endpoint, plus indices of lipid metabolism, and evaluations related to safety. CONCLUSIONS: There is lack of solid information on differences in the therapeutic effects of SGLT2 inhibitors and DPP4 inhibitors on multiple risk factors for cardiovascular diseases. It is anticipated that the results of the DIVERSITY-CVR study provides useful clinical data on the management of patients with T2DM, including reducing the risk of CVD. The results of this study will become available in 2019. Trial registration University Hospital Medical Information Network Clinical Trial Registry (UMIN000028014). Registered 30 June 2017.

Insulin-independent regulation of hepatic triglyceride synthesis by fatty acids.

A central paradox in type 2 diabetes is the apparent selective nature of hepatic insulin resistance--wherein insulin fails to suppress hepatic glucose production yet continues to stimulate lipogenesis, resulting in hyperglycemia, hyperlipidemia, and hepatic steatosis. Although efforts to explain this have focused on finding a branch point in insulin signaling where hepatic glucose and lipid metabolism diverge, we hypothesized that hepatic triglyceride synthesis could be driven by substrate, independent of changes in hepatic insulin signaling. We tested this hypothesis in rats by infusing [U-(13)C] palmitate to measure rates of fatty acid esterification into hepatic triglyceride while varying plasma fatty acid and insulin concentrations independently. These experiments were performed in normal rats, high fat-fed insulin-resistant rats, and insulin receptor 2'-O-methoxyethyl chimeric antisense oligonucleotide-treated rats. Rates of fatty acid esterification into hepatic triglyceride were found to be dependent on plasma fatty acid infusion rates, independent of changes in plasma insulin concentrations and independent of hepatocellular insulin signaling. Taken together, these results obviate a paradox of selective insulin resistance, because the major source of hepatic lipid synthesis, esterification of preformed fatty acids, is primarily dependent on substrate delivery and largely independent of hepatic insulin action.

Effectiveness of dapagliflozin on vascular endothelial function and glycemic control in patients with early-stage type 2 diabetes mellitus: DEFENCE study.

BACKGROUND: Recent studies reported that sodium glucose cotransporter 2 (SGLT2) inhibitors can potentially reduce the risk of cardiovascular mortality in patients with type 2 diabetes mellitus (T2DM). However, there is little or no information on the therapeutic effects of SGLT2 inhibitors on the progression of atherosclerosis. This dapagliflozin effectiveness on vascular endothelial function and glycemic control (DEFENCE) study was designed to determine the effects of dapagliflozin, a SGLT2 inhibitor, on endothelial function in patients with early-stage T2DM. METHODS: DEFENCE is a prospective, randomized, open-label, blinded-endpoint, parallel-group, comparative clinical trial. Between October 2015 and August 2016, 80 T2DM patients treated with 750 mg of metformin (hemoglobin A1c ≥6.0 and <8.0%, n = 80) were enrolled and randomized to receive either 1500 mg/day metformin (the metformin group, n = 40), or 750 mg/day metformin supplemented with 5 mg/day dapagliflozin (the dapagliflozin group, n = 40), for 16 weeks. The primary endpoint was a change in flow-mediated dilation (FMD) from baseline to the end of the 16-week treatment period. The secondary outcomes include changes in indexes of glycemic control, lipid metabolism, and oxidative stress, body composition, and safety evaluation. RESULTS: Although FMD tended to improve only in the dapagliflozin group, ΔFMD was comparable between the two groups. Analysis of patients with HbA1c >7.0% showed significant improvement of FMD in the dapagliflozin group than metformin group (P < 0.05). HbA1c, fasting plasma glucose, plasma glucagon, and body weight significantly decreased in both groups. Interestingly, urine 8-hydroxy-2'-deoxyguanosin, a biomarker of oxidative stress, was significantly lower in the dapagliflozin group than metformin group at 16 weeks (P < 0.001). CONCLUSIONS: Dapagliflozin add-on therapy to metformin for 16 weeks improved endothelial function, as assessed by FMD, in patients with inadequately controlled early-stage T2DM. Improvement in oxidative stress may contribute to the improvement in FMD. Trial registration University Hospital Medical Information Network Clinical Trial Registry (UMIN000018754).

A case of lean polycystic ovary syndrome with early stage of type 1 diabetes successfully treated with metformin.

Polycystic ovary syndrome (PCOS) is common in obese women with insulin resistant type 2 diabetes for which metformin treatment is getting established in addition to clomiphene. However, lean PCOS patients are sometimes accompanied with type 1 diabetes. It remains unclear whether these patients are insulin resistant and whether metformin is effective for them. A 32-year-old woman, who suffered from acne, hirsutism, and menstrual disorders since age 29, was diagnosed as PCOS by serum high LH levels and polycystic ovary on echography. Interestingly, her body mass index (BMI) had consistently been 21.0 kg/m2 since age 20. She was first treated with clomiphene for one year for infertility but it did not improve her menstrual cycle nor did she get pregnant during that period. She was then assessed with diabetes mellitus and subsequently diagnosed as type 1 diabetes with mild hyperglycemia (HbA1c 6.0%). Since her insulin secretion was still well preserved, to assess insulin sensitivity, hyperinsulinemic-euglycemic clamp test was performed and showed her to be insulin resistant. Low dose insulin and low dose metformin treatment was started without clomiphene. After her ovulation and menstrual cycle were ameliorated only one month later, her treatment was supplemented with clomiphene for the next three months enabling her to at last become pregnant. This report highlights the efficacy of metformin in lean PCOS with type 1 diabetes. Insulin therapy is essential for type 1 diabetes but hyperinsulinemia potentially exacerbates PCOS through hyperandrogenism. Metformin is therefore recommended for treatment of lean PCOS with type 1 diabetes as well as common obese PCOS with type 2 diabetes.

Efficacy and safety of repaglinide added to sitagliptin in Japanese patients with type 2 diabetes: A randomized 24-week open-label clinical trial.

Although sitagliptin and repaglinide monotherapies improve postprandial hyperglycemia, the long-term effects and safety of their combination has not been examined. In this randomized 24-week trial of Japanese patients with poor control (HbA1c 7.0-8.5%) by sitagliptin, we divided 40 patients randomly into two equal groups of the repaglinide add-on to sitagliptin (ADD-ON, n=20), or sitagliptin switched to repaglinide (SWITCH, n=20). The meal tolerance test was carried out at weeks 0 and 24. The primary outcomes were changes in HbA1c and area under the curves (AUC) of glucose from the baseline to week 24. The mean change in HbA1c from baseline to week 24 was larger in the ADD-ON (-0.87±0.63%, mean±SD), compared with the SWITCH (0.03±0.65%, p=0.000). Significant improvements were noted in the mean changes in fasting glucose and AUCs of glucose in the ADD-ON vs. SWITCH (p=0.007 and p=0.000). Insulin secretion relative to glucose elevation (ISG; defined as AUC insulin/AUC glucose) increased significantly in the ADD-ON, although the mean change in fasting insulin level was significantly decreased in the ADD-ON (p=0.015 and p=0.026). The AUC of glucagon was significantly lower at 24-week relative to baseline in the ADD-ON, but was not significant in the two groups (p=0.047 and p=0.056, respectively). The combination therapy produced significant reductions in HbA1c, AUC of glucose and fasting glucose compared with switching to repaglinide without weight gain or severe hypoglycemia. The improved glycemic control with this combination therapy may be at least in part due to augmentation of repaglinide-induced insulin secretion by sitagliptin.

CGI-58 knockdown sequesters diacylglycerols in lipid droplets/ER-preventing diacylglycerol-mediated hepatic insulin resistance.

Comparative gene identification 58 (CGI-58) is a lipid droplet-associated protein that promotes the hydrolysis of triglyceride by activating adipose triglyceride lipase. Loss-of-function mutations in CGI-58 in humans lead to Chanarin-Dorfman syndrome, a condition in which triglyceride accumulates in various tissues, including the skin, liver, muscle, and intestines. Therefore, without adequate CGI-58 expression, lipids are stored rather than used for fuel, signaling intermediates, and membrane biosynthesis. CGI-58 knockdown in mice using antisense oligonucleotide (ASO) treatment also leads to severe hepatic steatosis as well as increased hepatocellular diacylglycerol (DAG) content, a well-documented trigger of insulin resistance. Surprisingly, CGI-58 knockdown mice remain insulin-sensitive, seemingly dissociating DAG from the development of insulin resistance. Therefore, we sought to determine the mechanism responsible for this paradox. Hyperinsulinemic-euglycemic clamp studies reveal that the maintenance of insulin sensitivity with CGI-58 ASO treatment could entirely be attributed to protection from lipid-induced hepatic insulin resistance, despite the apparent lipotoxic conditions. Analysis of the cellular compartmentation of DAG revealed that DAG increased in the membrane fraction of high fat-fed mice, leading to PKCε activation and hepatic insulin resistance. However, DAG increased in lipid droplets or lipid-associated endoplasmic reticulum rather than the membrane of CGI-58 ASO-treated mice, and thus prevented PKCε translocation to the plasma membrane and induction of insulin resistance. Taken together, these results explain the disassociation of hepatic steatosis and DAG accumulation from hepatic insulin resistance in CGI-58 ASO-treated mice, and highlight the importance of intracellular compartmentation of DAG in causing lipotoxicity and hepatic insulin resistance.

Targeting steroid receptor coactivator 1 with antisense oligonucleotides increases insulin-stimulated skeletal muscle glucose uptake in chow-fed and high-fat-fed male rats.

The steroid receptor coactivator 1 (SRC1) regulates key metabolic pathways, including glucose homeostasis. SRC1(-/-) mice have decreased hepatic expression of gluconeogenic enzymes and a reduction in the rate of endogenous glucose production (EGP). We sought to determine whether decreasing hepatic and adipose SRC1 expression in normal adult rats would alter glucose homeostasis and insulin action. Regular chow-fed and high-fat-fed male Sprage-Dawley rats were treated with an antisense oligonucleotide (ASO) against SRC1 or a control ASO for 4 wk, followed by metabolic assessments. SRC1 ASO did not alter basal EGP or expression of gluconeogenic enzymes. Instead, SRC1 ASO increased insulin-stimulated whole body glucose disposal by ~30%, which was attributable largely to an increase in insulin-stimulated muscle glucose uptake. This was associated with an approximately sevenfold increase in adipose expression of lipocalin-type prostaglandin D2 synthase, a previously reported regulator of insulin sensitivity, and an approximately 70% increase in plasma PGD2 concentration. Muscle insulin signaling, AMPK activation, and tissue perfusion were unchanged. Although GLUT4 content was unchanged, SRC1 ASO increased the cleavage of tether-containing UBX domain for GLUT4, a regulator of GLUT4 translocation. These studies point to a novel role of adipose SRC1 as a regulator of insulin-stimulated muscle glucose uptake.

Role of patatin-like phospholipase domain-containing 3 on lipid-induced hepatic steatosis and insulin resistance in rats.

UNLABELLED: Genome-wide array studies have associated the patatin-like phospholipase domain-containing 3 (PNPLA3) gene polymorphisms with hepatic steatosis. However, it is unclear whether PNPLA3 functions as a lipase or a lipogenic enzyme and whether PNPLA3 is involved in the pathogenesis of hepatic insulin resistance. To address these questions we treated high-fat-fed rats with specific antisense oligonucleotides to decrease hepatic and adipose pnpla3 expression. Reducing pnpla3 expression prevented hepatic steatosis, which could be attributed to decreased fatty acid esterification measured by the incorporation of [U-(13) C]-palmitate into hepatic triglyceride. While the precursors for phosphatidic acid (PA) (long-chain fatty acyl-CoAs and lysophosphatidic acid [LPA]) were not decreased, we did observe an ∼20% reduction in the hepatic PA content, ∼35% reduction in the PA/LPA ratio, and ∼60%-70% reduction in transacylation activity at the level of acyl-CoA:1-acylglycerol-sn-3-phosphate acyltransferase. These changes were associated with an ∼50% reduction in hepatic diacylglycerol (DAG) content, an ∼80% reduction in hepatic protein kinase Cε activation, and increased hepatic insulin sensitivity, as reflected by a 2-fold greater suppression of endogenous glucose production during the hyperinsulinemic-euglycemic clamp. Finally, in humans, hepatic PNPLA3 messenger RNA (mRNA) expression was strongly correlated with hepatic triglyceride and DAG content, supporting a potential lipogenic role of PNPLA3 in humans. CONCLUSION: PNPLA3 may function primarily in a lipogenic capacity and inhibition of PNPLA3 may be a novel therapeutic approach for treatment of nonalcoholic fatty liver disease-associated hepatic insulin resistance.

Cellular mechanism of insulin resistance in nonalcoholic fatty liver disease.

Insulin resistance is associated with nonalcoholic fatty liver disease (NAFLD) and is a major factor in the pathogenesis of type 2 diabetes. The development of hepatic insulin resistance has been ascribed to multiple causes, including inflammation, endoplasmic reticulum (ER) stress, and accumulation of hepatocellular lipids in animal models of NAFLD. However, it is unknown whether these same cellular mechanisms link insulin resistance to hepatic steatosis in humans. To examine the cellular mechanisms that link hepatic steatosis to insulin resistance, we comprehensively assessed each of these pathways by using flash-frozen liver biopsies obtained from 37 obese, nondiabetic individuals and correlating key hepatic and plasma markers of inflammation, ER stress, and lipids with the homeostatic model assessment of insulin resistance index. We found that hepatic diacylglycerol (DAG) content in cytoplasmic lipid droplets was the best predictor of insulin resistance (R = 0.80, P < 0.001), and it was responsible for 64% of the variability in insulin sensitivity. Hepatic DAG content was also strongly correlated with activation of hepatic PKCε (R = 0.67, P < 0.001), which impairs insulin signaling. In contrast, there was no significant association between insulin resistance and other putative lipid metabolites or plasma or hepatic markers of inflammation. ER stress markers were only partly correlated with insulin resistance. In conclusion, these data show that hepatic DAG content in lipid droplets is the best predictor of insulin resistance in humans, and they support the hypothesis that NAFLD-associated hepatic insulin resistance is caused by an increase in hepatic DAG content, which results in activation of PKCε.

Thyroid hormone receptor-ß agonists prevent hepatic steatosis in fat-fed rats but impair insulin sensitivity via discrete pathways.

Liver-specific thyroid hormone receptor-ß (TRß)-specific agonists are potent lipid-lowering drugs that also hold promise for treating nonalcoholic fatty liver disease and hepatic insulin resistance. We investigated the effect of two TRß agonists (GC-1 and KB-2115) in high-fat-fed male Sprague-Dawley rats treated for 10 days. GC-1 treatment reduced hepatic triglyceride content by 75%, but the rats developed fasting hyperglycemia and hyperinsulinemia, attributable to increased endogenous glucose production (EGP) and diminished hepatic insulin sensitivity. GC-1 also increased white adipose tissue lipolysis; the resulting increase in glycerol flux may have contributed to the increase in EGP. KB-2115, a more TRß- and liver-specific thyromimetic, also prevented hepatic steatosis but did not induce fasting hyperglycemia, increase basal EGP rate, or diminish hepatic insulin sensitivity. Surprisingly, insulin-stimulated peripheral glucose disposal was diminished because of a decrease in insulin-stimulated skeletal muscle glucose uptake. Skeletal muscle insulin signaling was unaffected. Instead, KB-2115 treatment was associated with a decrease in GLUT4 protein content. Thus, although both GC-1 and KB-2115 potently treat hepatic steatosis in fat-fed rats, they each worsen insulin action via specific and discrete mechanisms. The development of future TRß agonists must consider the potential adverse effects on insulin sensitivity.

Changes in subjective sleep quality in patients with type 2 diabetes who did not use Sleep agents: a cross-sectional study according to age and clinical background.

AIM: Diabetes and aging are both well-established risk factors for insomnia. Therefore, we investigated the changes in subjective sleep quality in relation to clinical backgrounds and age in patients with type 2 diabetes mellitus (T2DM). METHODS: This cross-sectional study included 380 participants with T2DM who were between 18 and 79 years of age from our outpatient clinics. Individuals with any symptoms and medical histories associated with obstructive sleep apnea (OSA) were excluded from the interview and analyses. Data were collected using self-administered questionnaires, namely the Pittsburgh Sleep Quality Index (PSQI) and the Morning-Evening Questionnaire (MEQ), as well as medical records and blood samples. We performed stratified analyses according to age decades. RESULTS: The number of patients in the age groups (in years) was as follows: < 50 (n = 69), 50-60 (n = 52), 60-70 (n = 138), and 70-80 (n = 121). PSQI score was highest in the < 50 group (4.99 ± 2.40), and significantly decreased with age (p < 0.05). Body mass index (BMI) was also highest in the < 50 group (25.5 ± 4.8 kg/m2), and markedly decreased with age (p < 0.01). Interestingly, BMI was significantly correlated with the PSQI score (rs = 0.157, p < 0.05). We also found that younger patients had shorter sleep duration, stronger daytime sleepiness, and a tendency for the evening type. CONCLUSION: Younger T2DM patients had poorer sleep quality and higher BMI. Our findings suggest that insomnia should be accounted for as a potential comorbidity when examining or treating patients with T2DM and obesity even in the younger population.

Simplification of complex insulin regimens using canagliflozin or liraglutide in patients with well-controlled type 2 diabetes: A 24-week randomized controlled trial.

AIMS/INTRODUCTION: We investigated the potential use of canagliflozin, in comparison with liraglutide, as an alternative to bolus insulin in patients with well-controlled type 2 diabetes mellitus receiving multiple daily insulin injection therapy. MATERIALS AND METHODS: In 40 patients, with glycated hemoglobin (HbA1c) levels <7.5% controlled by multiple daily insulin injection therapy, all bolus insulin was randomly switched to canagliflozin (100 mg/day) or liraglutide (0.3-0.9 mg/day) for 24 weeks. Basal insulin was continued with dose adjustment according to a predefined algorithm. The end-points were the change in the HbA1c level, glycemic variability assessed by continuous glucose monitoring, body mass index, insulin dose, quality of life (QOL) and safety assessments. Factors influencing the changes in QOL were also assessed using a simple regression analysis. RESULTS: The change in HbA1c from baseline was comparable between the treatments. Both treatments maintained the HbA1c level to the baseline levels with stable glucose variability and no severe hypoglycemia for 24 weeks, decreased total insulin dose, and significantly increased the QOL score. The change in QOL was significantly associated with injection frequency. CONCLUSIONS: For patients with well-controlled type 2 diabetes mellitus, under the support of basal insulin, complex insulin regimens can be simplified by replacing all bolus insulin with once-daily canagliflozin or liraglutide, which improves patients' QOL.

Chronotherapeutic efficacy of suvorexant on sleep quality and metabolic parameters in patients with type 2 diabetes and insomnia.

AIMS: This study aimed to assess the chronotherapeutic efficacy of suvorexant on subjective sleep parameters and metabolic parameters in patients with type 2 diabetes and insomnia. METHODS: Thirteen patients with type 2 diabetes who met the Pittsburg Sleep Quality index criteria for primary insomnia took suvorexant 20 mg/day (15 mg/day for ≥65 years) for 14 ± 2 weeks. The following parameters were assessed before and after the treatment: sleep diary for sleep duration and quality (i.e., sleep onset latency, waking after sleep onset, and sleep efficiency [sSE]), Insomnia Severity Index, clinical and biochemical data, continuous glucose monitoring (CGM), and validated self-administered questionnaire on food intake. RESULTS: Suvorexant significantly improved sSE, abdominal circumference, and sucrose intake (all p < 0.05), but did not change HbA1c, CGM parameters, or body weight. Correlation analysis revealed that changes in sSE were associated with those in HbA1c and body weight (r = -0.61 and r = -0.66, respectively; both p < 0.05). CONCLUSIONS: Suvorexant significantly improved sleep quality and obesity-associated parameters in patients with type 2 diabetes in 14 weeks. Improvements in sleep quality were associated with improvements in glycemic control. Sleep disorder treatment using suvorexant may provide metabolic benefits for patients with type 2 diabetes.