Blocking Thromboxane-Prostanoid Receptor Signaling Attenuates Lipopolysaccharide- and Stearic Acid-Induced Inflammatory Response in Human PBMCs.

Inflammation is implicated in the etiology of obesity-related diseases. Thromboxane-prostanoid receptor (TPR) is known to play a role in mediating an inflammatory response in a variety of cells. Gut-derived lipopolysaccharide (LPS), a TLR4 agonist, is elevated in obesity. Moreover, free fatty acids (FFAs) are important mediators of obesity-related inflammation. However, the role and mechanisms by which TPR regulates the inflammatory response in human immune cells remain unclear. We sought to determine the link between TPR and obesity and the role/mechanisms by which TPR alters LPS- or stearic acid (SA)-induced inflammatory responses in PBMCs. Cells were pre-treated with agents blocking TPR signaling, followed by treatment with LPS or stearic acid (SA). Our findings showed that TPR mRNA levels are higher in PBMCs from individuals with obesity. Blockade of TPR as well as ROCK, which acts downstream of TPR, attenuated LPS- and/or SA-induced pro-inflammatory responses. On the other hand, TPR activation using its agonist enhanced the pro-inflammatory effects of LPS and/or SA. Of note, the TPR agonist by itself elicits an inflammatory response, which was attenuated by blocking TPR or ROCK. Our data suggest that TPR plays a key role in promoting an inflammatory response in human PBMCs, and this effect is mediated via TLR4 and/or ROCK signaling.

A Pilot Study on the Proteomics Profile of Serum Exosome-Enriched Extracellular Vesicles from Normal versus Individuals with Obesity-Related Insulin Resistance.

OBJECTIVE: Circulating exosome-enriched extracellular vesicles (EVs) have drawn considerable importance in obesity-related insulin-resistance (IR). We sought to compare the proteomics profile of serum exosomes from normal individuals and those with obesity and IR. METHODS: We isolated serum exosomes from male subjects with obesity and insulin resistance (Ob-IR, HOMA-IR > 2.0) and lean/overweight insulin-sensitive (Normal (N), HOMA-IR < 2.0) individuals. The differential protein expression between the two groups was detected by a label-free quantitative mass spectrometry analysis followed by GO annotation and ingenuity pathway analysis (IPA). RESULTS: We identified 23 upregulated and 46 downregulated proteins between Ob-IR and N groups. Some of these proteins are involved in altering insulin signaling (VPS13C, TBC1D32, TTR, and ADIPOQ), inflammation (NFκB and CRP), and B-cell proliferation/activation (IGLV4-69, IGKV1D-13, and IGHV4-28). GO analysis revealed that the differentially expressed proteins (DEPs) are mainly involved in regulating immune cell activation and are located in extracellular space. IPA analysis showed that top molecules mediating IR, inflammation and B-cell activation were upregulated in Ob-IR subjects compared to N subjects. CONCLUSIONS: Serum exosomal proteins can be used as biomarkers to identify the future risk of diabetes and a therapeutic target to prevent or slow down the progression of diabetes in high-risk individuals.

Cardiovascular Outcomes in GRADE (Glycemia Reduction Approaches in Type 2 Diabetes: A Comparative Effectiveness Study).

BACKGROUND: Cardiovascular disease is a major cause of morbidity and mortality in patients with type 2 diabetes. The effects of glucose-lowering medications on cardiovascular outcomes in individuals with type 2 diabetes and low cardiovascular risk are unclear. We investigated cardiovascular outcomes by treatment group in participants randomly assigned to insulin glargine, glimepiride, liraglutide, or sitagliptin, added to baseline metformin, in GRADE (Glycemia Reduction Approaches in Type 2 Diabetes: A Comparative Effectiveness Study). METHODS: A total of 5047 participants with a mean±SD age of 57.2±10.0 years, type 2 diabetes duration of 4.0±2.7 years, and low baseline prevalence of cardiovascular disease (myocardial infarction, 5.1%; cerebrovascular accident, 2.0%) were followed for a median of 5 years. Prespecified outcomes included between-group time-to-first event analyses of MACE-3 (composite of major adverse cardiovascular events: cardiovascular death, myocardial infarction, and stroke), MACE-4 (MACE-3+unstable angina requiring hospitalization or revascularization), MACE-5 (MACE-4+coronary revascularization), MACE-6 (MACE-5+hospitalization for heart failure), and the individual components. MACE outcomes and hospitalization for heart failure in the liraglutide-treated group were compared with the other groups combined using Cox proportional hazards models. MACE-6 was also analyzed as recurrent events using a proportional rate model to compare all treatment groups. RESULTS: We observed no statistically significant differences in the cumulative incidence of first MACE-3, MACE-4, MACE-5, or MACE-6, or their individual components, by randomized treatment group. However, when compared with the other treatment groups combined, the liraglutide-treated group had a significantly lower risk of MACE-5 (adjusted hazard ratio, 0.70 [95% CI, 0.54-0.91]; P=0.021), MACE-6 (adjusted hazard ratio, 0.70 [95% CI, 0.55-0.90]; P=0.021), and hospitalization for heart failure (adjusted hazard ratio, 0.49 [95% CI, 0.28-0.86]; P=0.022). Compared with the liraglutide group, significantly higher rates of recurrent MACE-6 events occurred in the groups treated with glimepiride (rate ratio, 1.61 [95% CI, 1.13-2.29]) or sitagliptin (rate ratio 1.75; [95% CI, 1.24-2.48]). CONCLUSIONS: This comparative effectiveness study of a contemporary cohort of adults with type 2 diabetes, largely without established cardiovascular disease, suggests that liraglutide treatment may reduce the risk of cardiovascular events in patients at relatively low risk compared with other commonly used glucose-lowering medications. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01794143.

Racial differences in measures of glycemia in the Vitamin D and Type 2 Diabetes (D2d) Study: a secondary analysis of a randomized trial.

INTRODUCTION: Understanding how race may influence the association between A1c and glycemia can improve diabetes screening. We sought to determine whether, for a given A1c level, glucose levels during an oral glucose tolerance test (OGTT) differed by race. RESEARCH DESIGN AND METHODS: From data collected at 22 US clinical sites, we conducted a cross-sectional study of concurrently measured A1c and OGTT and observational longitudinal follow-up of the subset with high-risk pre-diabetes. Numerical integration methods were used to calculate area under the glycemic curve (AUCglu) during OGTT and least squares regression model to estimate A1c for a given AUCglu by race, controlling for potential confounders. RESULTS: 1016 black, 2658 white, and 193 Asian persons at risk of diabetes were included in cross-sectional analysis. Of these, 2154 with high-risk pre-diabetes were followed for 2.5 years. For a given A1c level, AUCglu was lower in black versus white participants. After adjustment for potential confounders, A1c levels for a given AUCglu quintile were 0.15-0.20 and 0.02-0.19 percentage points higher in black and Asian compared with white participants, respectively (p<0.05). In longitudinal analyses, black participants were more likely to be diagnosed with diabetes by A1c than white participants (28% vs 10%, respectively; p<0.01). Black and Asian participants were less likely to be diagnosed by fasting glucose than white participants (16% vs 15% vs 37%, respectively; p<0.05). Black participants with A1c levels in the lower-level quintiles had greater increase in A1c over time compared with white participants. CONCLUSIONS: Use of additional testing beyond A1c to screen for diabetes may better stratify diabetes risk in the diverse US population.

GAD65Abs Are Not Associated With Beta-Cell Dysfunction in Patients With T2D in the GRADE Study.

Context: Autoantibodies directed against the 65-kilodalton isoform of glutamic acid decarboxylase (GAD65Abs) are markers of autoimmune type 1 diabetes (T1D) but are also present in patients with Latent Autoimmune Diabetes of Adults and autoimmune neuromuscular diseases, and also in healthy individuals. Phenotypic differences between these conditions are reflected in epitope-specific GAD65Abs and anti-idiotypic antibodies (anti-Id) against GAD65Abs. We previously reported that 7.8% of T2D patients in the GRADE study have GAD65Abs but found that GAD65Ab positivity was not correlated with beta-cell function, glycated hemoglobin (HbA1c), or fasting glucose levels. Context: In this study, we aimed to better characterize islet autoantibodies in this T2D cohort. This is an ancillary study to NCT01794143. Methods: We stringently defined GAD65Ab positivity with a competition assay, analyzed GAD65Ab-specific epitopes, and measured GAD65Ab-specific anti-Id in serum. Results: Competition assays confirmed that 5.9% of the patients were GAD65Ab positive, but beta-cell function was not associated with GAD65Ab positivity, GAD65Ab epitope specificity or GAD65Ab-specific anti-Id. GAD65-related autoantibody responses in GRADE T2D patients resemble profiles in healthy individuals (low GAD65Ab titers, presence of a single autoantibody, lack of a distinct epitope pattern, and presence of anti-Id to diabetes-associated GAD65Ab). In this T2D cohort, GAD65Ab positivity is likely unrelated to the pathogenesis of beta-cell dysfunction. Conclusion: Evidence for islet autoimmunity in the pathophysiology of T2D beta-cell dysfunction is growing, but T1D-associated autoantibodies may not accurately reflect the nature of their autoimmune process.

Impact of Insulin Sensitivity and ß-Cell Function Over Time on Glycemic Outcomes in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE): Differential Treatment Effects of Dual Therapy.

OBJECTIVE: To compare the effects of insulin sensitivity and ß-cell function over time on HbA1c and durability of glycemic control in response to dual therapy. RESEARCH DESIGN AND METHODS: GRADE participants were randomized to glimepiride (n = 1,254), liraglutide (n = 1,262), or sitagliptin (n = 1,268) added to baseline metformin and followed for mean ± SD 5.0 ± 1.3 years, with HbA1c assessed quarterly and oral glucose tolerance tests at baseline, 1, 3, and 5 years. We related time-varying insulin sensitivity (HOMA 2 of insulin sensitivity [HOMA2-%S]) and early (0-30 min) and total (0-120 min) C-peptide (CP) responses to changes in HbA1c and glycemic failure (primary outcome HbA1c ≥7% [53 mmol/mol] and secondary outcome HbA1c >7.5% [58 mmol/mol]) and examined differential treatment responses. RESULTS: Higher HOMA2-%S was associated with greater initial HbA1c lowering (3 months) but not subsequent HbA1c rise. Greater CP responses were associated with a greater initial treatment response and slower subsequent HbA1c rise. Higher HOMA2-%S and CP responses were each associated with lower risk of primary and secondary outcomes. These associations differed by treatment. In the sitagliptin group, HOMA2-%S and CP responses had greater impact on initial HbA1c reduction (test of heterogeneity, P = 0.009 HOMA2-%S, P = 0.018 early CP, P = 0.001 total CP) and risk of primary outcome (P = 0.005 HOMA2-%S, P = 0.11 early CP, P = 0.025 total CP) but lesser impact on HbA1c rise (P = 0.175 HOMA2-%S, P = 0.006 early CP, P < 0.001 total CP) in comparisons with the glimepiride and liraglutide groups. There were no differential treatment effects on secondary outcome. CONCLUSIONS: Insulin sensitivity and ß-cell function affected treatment outcomes irrespective of drug assignment, with greater impact in the sitagliptin group on initial (short-term) HbA1c response in comparison with the glimepiride and liraglutide groups.

Glycemic and metabolic sub-classification of prediabetes and risk factors for cardiovascular disease in the D2d cohort.

Objectives: Prediabetes represents a spectrum of metabolic abnormalities, including insulin resistance and secretory impairment, that carries increased cardiovascular disease (CVD) risk. It is unclear whether specific glycemic and metabolic sub-classifications are associated with CVD risk. This cross-sectional analysis of 3946 participants from the Vitamin D and Type 2 Diabetes (D2d) study cohort aimed to determine the associations between various baseline CVD risk factors, glycemic sub-classifications of prediabetes (FPG, 2hPG, and HbA1c), and measures of insulin sensitivity and secretion from an OGTT. Methods: The metabolic syndrome and atherosclerotic cardiovascular disease (ASCVD) risk scores were determined for tertiles of insulin sensitivity (HOMA2S) and insulinogenic index (IGI). Unadjusted analyses showed elevated CVD risk factors in the lowest tertile for both IGI and HOMA2S. Results: After adjustment for age, gender, race, obesity, and smoking status, the association remained between HOMA2S and ASCVD score (r = -0.11, p< 0.001) but not for IGI. Those who met at least 2 diagnosic criteria for prediabetes had the largest proportion (> 40%) of participants with high ASCVD risk score >20. A higher percentage of individuals that met all 3 criteria for prediabetes had metabolic syndrome and ASCVD risk score >20 (87.2% and 15.3%, respectively) than those who only met 1 prediabetes criterion (51.6% and 7.1%, respectively). Conclusions: In conclusion, multiple metabolic (HOMA2S, IGI) and glycemic criteria of prediabetes (FPG, 2hPG, & HbA1c) are needed to fully recognize the elevated CVD risk profile that can manifest in prediabetes.

BMI, insulin sensitivity, and cognition in early type 2 diabetes: The Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study.

OBJECTIVE: This study explored the association of BMI and insulin sensitivity with cognitive performance in type 2 diabetes. METHODS: A cross-sectional analysis of data from the baseline assessment of the Glycemia Reduction Approaches in Diabetes: a Comparative Effectiveness Study (GRADE) was conducted. BMI was used as a surrogate of adiposity and the Matsuda index as the measure of insulin sensitivity. Cognitive tests included the Spanish English Verbal Learning Test, the Digit Symbol Substitution Test, and the letter and animal fluency tests. RESULTS: Cognitive assessments were completed by 5018 (99.4%) of 5047 participants aged 56.7 ± 10.0 years, of whom 36.4% were female. Higher BMI and lower insulin sensitivity were related to better performance on memory and verbal fluency tests. In models including BMI and insulin sensitivity simultaneously, only higher BMI was related to better cognitive performance. CONCLUSIONS: In this study, higher BMI and lower insulin sensitivity in type 2 diabetes were cross-sectionally associated with better cognitive performance. However, only higher BMI was related to cognitive performance when both BMI and insulin sensitivity were considered simultaneously. The causality and mechanisms for this association need to be determined in future studies.

Once-Weekly Insulin Icodec vs Once-Daily Insulin Degludec in Adults With Insulin-Naive Type 2 Diabetes: The ONWARDS 3 Randomized Clinical Trial.

Importance: Once-weekly insulin icodec could provide a simpler dosing alternative to daily basal insulin in people with type 2 diabetes. Objective: To evaluate the efficacy and safety of once-weekly icodec vs once-daily insulin degludec in people with insulin-naive type 2 diabetes. Design, Setting, and Participants: Randomized, double-masked, noninferiority, treat-to-target, phase 3a trial conducted from March 2021 to June 2022 at 92 sites in 11 countries in adults with type 2 diabetes treated with any noninsulin glucose-lowering agents with hemoglobin A1c (HbA1c) of 7%-11% (53-97 mmol/mol). Interventions: Participants were randomly assigned in a 1:1 ratio to receive either once-weekly icodec and once-daily placebo (icodec group; n = 294) or once-daily degludec and once-weekly placebo (degludec group; n = 294). Main Outcomes and Measures: The primary end point was change in HbA1c from baseline to week 26 (noninferiority margin, 0.3% percentage points). Secondary end points included change in fasting plasma glucose from baseline to week 26, mean weekly insulin dose during the last 2 weeks of treatment, body weight change from baseline to week 26, and number of level 2 (clinically significant; glucose level <54 mg/dL) and level 3 (severe; requiring external assistance for recovery) hypoglycemic episodes. Results: Among 588 randomized participants (mean [SD] age, 58 [10] years; 219 [37%] women), 564 (96%) completed the trial. Mean HbA1c level decreased from 8.6% (observed) to 7.0% (estimated) at 26 weeks in the icodec group and from 8.5% (observed) to 7.2% (estimated) in the degludec group (estimated treatment difference [ETD], -0.2 [95% CI, -0.3 to -0.1] percentage points), confirming noninferiority (P < .001) and superiority (P = .002). There were no significant differences between the icodec and degludec groups for fasting plasma glucose change from baseline to week 26 (ETD, 0 [95% CI, -6 to 5] mg/dL; P = .90), mean weekly insulin dose during the last 2 weeks of treatment, or body weight change from baseline to week 26 (2.8 kg vs 2.3 kg; ETD, 0.46 [95% CI, -0.19 to 1.10] kg; P = .17). Combined level 2 or 3 hypoglycemia rates were numerically higher in the icodec group than the degludec group from week 0 to 31 (0.31 vs 0.15 events per patient-year exposure; P = .11) and statistically higher in the icodec group from week 0 to 26 (0.35 vs 0.12 events per patient-year exposure; P = .01). Conclusions and Relevance: Among people with insulin-naive type 2 diabetes, once-weekly icodec demonstrated superior HbA1c reduction to once-daily degludec after 26 weeks of treatment, with no difference in weight change and a higher rate of combined level 2 or 3 hypoglycemic events in the context of less than 1 event per patient-year exposure in both groups. Trial Registration: ClinicalTrials.gov Identifier: NCT04795531.

Glycated Albumin Correlates With Time-in-Range Better Than HbA1c or Fructosamine.

CONTEXT: Intermediate-term glycemic control metrics may represent a viable alternative to continuous glucose monitoring (CGM) in patients without access to CGM. OBJECTIVE: This work aimed to compare the relationship between CGM parameters and glycated albumin (GA), glycated hemoglobin A1c (HbA1c), and fructosamine for 24 weeks. METHODS: We conducted exploratory comparative analyses of CGM subgroup data from a previously published 24-week prospective study of assay performance in 8 US clinics. Participants included 34 individuals with type 1 (n = 18) and type 2 diabetes (n = 16) undergoing changes to improve glycemic control (n = 22; group 1) or with stable diabetes therapy (n = 12; group 2). Main outcome measures included Pearson correlations between CGM and glycemic indices and receiver operating characteristic (ROC) analysis of glycemic index values predictive of time in range (TIR) greater than 70%. RESULTS: At weeks 4 and 8, GA correlations with TIR were higher than HbA1c correlations in group 1. In group 2, GA correlations with TIR were statistically significant, whereas HbA1c correlations were not. In both groups over the first 12 weeks, GA correlations with TIR were higher than fructosamine-TIR correlations. In the ROC analysis, GA predicted a TIR greater than 70% during weeks 2 to 24 (area under the curve >0.80); HbA1c was predictive during weeks 12 to 24. Cutoff values for TIR greater than 70% were 17.5% (sensitivity and specificity, 0.88) for GA and 7.3% (0.86) for HbA1c. CONCLUSION: GA is the most accurate predictor of TIR over 8 weeks compared with other glycemic indices, which may assist in clinical evaluation of changes in treatment where CGM is not possible and it is too early to use HbA1c (NCT02489773).

Glycemic control level alters working memory neural dynamics in adults with type 2 diabetes.

Poor glycemic control in type 2 diabetes has been associated with accentuated age-related cognitive decline, although the underlying neural mechanisms are not well understood. The current study sought to identify the impact of glycemic control on the neural dynamics serving working memory in adults with type 2 diabetes. Participants (n = 34, ages = 55-73) performed a working memory task while undergoing MEG. Significant neural responses were examined relative to poorer (A1c > 7.0%) or tighter glycemic control (A1c < 7.0%). Those with poorer glycemic control showed diminished responses within left temporal and prefrontal regions during encoding and showed diminished responses within right occipital cortex during maintenance but showed an enhanced activity in the left temporal, occipital, and cerebellar regions during maintenance. Notably, left temporal activity in encoding and left lateral occipital activity in maintenance significantly predicted performance on the task such that diminished temporal activity led to longer reaction times, which were driven by the poorer glycemic control group. Greater lateral occipital activity during maintenance was associated with both lower accuracy and longer reaction times across all participants. These findings suggest that glycemic control has a robust impact on the neural dynamics serving working memory, with distinct effects by subprocess (e.g. encoding vs. maintenance) and direct effects on behavior.

Indices of hepatic steatosis and fibrosis in prediabetes and association with diabetes development in the vitamin D and type 2 diabetes study.

AIMS: Non-alcoholic fatty liver disease (NAFLD) is a common comorbidity that leads to poor outcomes in people at high risk for development of type 2 diabetes (T2D). Vitamin D is a possible mediator. In the vitamin D and type 2 diabetes study (D2d), we investigated the relationship of baseline indices of NAFLD with incident T2D and whether the effect of vitamin D on diabetes was modified by NAFLD. METHODS: Cross-sectional associations of indices of NAFLD with glycemia and vitamin D status were assessed in 3972 individuals screened for the D2d study. In those with prediabetes randomized to vitamin D or placebo (n = 2423), we examined longitudinal associations of NAFLD indices with incident T2D. We used validated non-invasive scores to assess steatosis [(hepatic steatosis index (HSI); NAFLD-liver fat score (NAFLD-LFS)] and advanced fibrosis [fibrosis-4 (FIB-4) index; AST to Platelet Ratio Index (APRI)]. RESULTS: Eighty-five percent of screened participants had likely steatosis by HSI and 71 % by NAFLD-LFS; 3 % were likely to have advanced fibrosis by FIB-4 and 1.2 % by APRI. FIB-4 indicated that 20.4 % of individuals require further follow up to assess liver health. Steatosis and fibrosis scores were higher among participants with worse glycemia. The NAFLD-LFS and APRI predicted development of diabetes (hazard ratios [95%CI] 1.35 [1.07, 1.70]; P = 0.012) and 2.36 (1.23, 4.54; P = 0.010), respectively). The effect of vitamin D on diabetes risk was not modified by baseline NAFLD indices. Individuals with likely steatosis had a smaller increase in serum 25-hydroxyvitamin D level in response to vitamin D than those without steatosis. CONCLUSIONS: The predicted high prevalence of steatosis, the need for further fibrosis workup, and the relationship between liver health and incident T2D suggest that routine screening with clinically accessible scores may be an important strategy to reduce disease burden.

Higher burden of cardiometabolic and socioeconomic risk factors in women with type 2 diabetes: an analysis of the Glycemic Reduction Approaches in Diabetes (GRADE) baseline cohort.

INTRODUCTION: Type 2 diabetes mellitus (T2DM) is a powerful risk factor for cardiovascular disease (CVD), conferring a greater relative risk in women than men. We sought to examine sex differences in cardiometabolic risk factors and management in the contemporary cohort represented by the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE). RESEARCH DESIGN AND METHODS: GRADE enrolled 5047 participants (1837 women, 3210 men) with T2DM on metformin monotherapy at baseline. The current report is a cross-sectional analysis of baseline data collected July 2013 to August 2017. RESULTS: Compared with men, women had a higher mean body mass index (BMI), greater prevalence of severe obesity (BMI≥40 kg/m2), higher mean LDL cholesterol, greater prevalence of low HDL cholesterol, and were less likely to receive statin treatment and achieve target LDL, with a generally greater prevalence of these risk factors in younger women. Women with hypertension were equally likely to achieve blood pressure targets as men; however, women were less likely to receive ACE inhibitors or angiotensin receptor blockers. Women were more likely to be divorced, separated or widowed, and had fewer years of education and lower incomes. CONCLUSIONS: This contemporary cohort demonstrates that women with T2DM continue to have a greater burden of cardiometabolic and socioeconomic risk factors than men, particularly younger women. Attention to these persisting disparities is needed to reduce the burden of CVD in women. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov (NCT01794143).

Myristic Acid Supplementation Aggravates High Fat Diet-Induced Adipose Inflammation and Systemic Insulin Resistance in Mice.

Saturated fatty acids (SFAs) are considered to be detrimental to human health. One of the SFAs, myristic acid (MA), is known to exert a hypercholesterolemic effect in mice as well as humans. However, its effects on altering adipose tissue (AT) inflammation and systemic insulin resistance (IR) in obesity are still unclear. Here, we sought to determine the effects of a high fat (HF) diet supplemented with MA on obesity-associated metabolic disorders in mice. Wild-type C57BL/6 mice were fed a HF diet in the presence or absence of 3% MA for 12 weeks. Plasma lipids, plasma adipokines, AT inflammation, systemic IR, glucose homeostasis, and hepatic steatosis were assessed. The body weight and visceral adipose tissue (VAT) mass were significantly higher in mice receiving the HF+MA diet compared to HF diet-fed controls. Plasma total cholesterol levels were marginally increased in HF+MA-fed mice compared to controls. Fasting blood glucose was comparable between HF and HF+MA-fed mice. Interestingly, the plasma insulin and HOMA-IR index, a measure of insulin resistance, were significantly higher in HF+MA-fed mice compared to HF controls. Macrophage and inflammatory markers were significantly elevated in the AT and AT-derived stromal vascular cells upon MA feeding. Moreover, the level of circulating resistin, an adipokine promoting insulin resistance, was significantly higher in HF+MA-fed mice compared with HF controls. The insulin tolerance test revealed that the IR was higher in mice receiving the MA supplementation compared to HF controls. Moreover, the glucose tolerance test showed impairment in systemic glucose homeostasis in MA-fed mice. Analyses of liver samples showed a trend towards an increase in liver TG upon MA feeding. However, markers of oxidative stress and inflammation were reduced in the liver of mice fed an MA diet compared to controls. Taken together, our data suggest that chronic administration of MA in diet exacerbates obesity-associated insulin resistance and this effect is mediated in part, via increased AT inflammation and increased secretion of resistin.

The effect of vitamin D supplementation on cardiovascular risk in patients with prediabetes: A secondary analysis of the D2d study.

AIMS: Low blood 25(OH)D level is associated with increased cardiovascular disease (CVD) risk. Additionally, individuals with prediabetes are at higher risk for CVD than individuals with normoglycemia. We investigated the effects of vitamin D supplementation on CVD outcomes in the vitamin D and type 2 diabetes (D2d) study, a large trial among adults with prediabetes. METHODS: 2423 participants were randomized to 4000 IU/day of vitamin D3 or placebo and followed for median 3.0 years for new-onset diabetes. In pre-specified secondary analyses, we examined the effect of vitamin D supplementation on composite Major Adverse Cardiovascular Events (MACE); expanded MACE (MACE + revascularization); atherosclerotic CVD (ASCVD) risk score; and individual CVD risk factors (blood pressure, lipids, high-sensitivity C-reactive protein). Cox models compared hazard ratios (HR) between the two groups on MACE and expanded MACE. RESULTS: Mean age was 60 years, 45 % were women, 13 % had history of CVD. Twenty-one participants assigned to vitamin D and 12 participants assigned to placebo met the MACE outcome (HR 1.81, 95%CI 0.89 to 3.69). There were 27 expanded MACE outcomes in each group (HR 1.02, 95%CI, 0.59 to 1.76). There were no significant differences between vitamin D and placebo in individual CVD risk factors, but change in ASCVD risk score favored the vitamin D group (-0.45 %, 95%CI -0.75 to -0.15). CONCLUSIONS: In people with prediabetes not selected for vitamin D insufficiency and with intermediate CVD risk, vitamin D supplementation did not decrease MACE but had a small favorable effect on ASCVD risk score. TRIAL REGISTRATION: D2d ClinicalTrials.gov number, NCT01942694, prospectively registered September 16, 2013.

Differential impact of glycemic control and comorbid conditions on the neurophysiology underlying task switching in older adults with type 2 diabetes.

Type 2 diabetes is known to negatively affect higher order cognition and the brain, but the underlying mechanisms are not fully understood. In particular, glycemic control and common comorbidities are both thought to contribute to alterations in cortical neurophysiology in type 2 diabetes, but their specific impact remains unknown. The current study probed the dynamics underlying cognitive control in older participants with type 2 diabetes, with and without additional comorbid conditions (i.e., cardiovascular disease, nephropathy, peripheral neuropathy, retinopathy), using a task switching paradigm and a dynamic functional brain mapping method based on magnetoencephalography (MEG). We hypothesized that neural dynamics would be differentially impacted by the level of glycemic control (i.e., diabetes itself) and the burden of additional comorbid conditions. Supporting this hypothesis, our findings indicated separable, but widespread alterations across frontal, parietal, temporal and cerebellum regions in neural task-switch costs in type 2 diabetes that were differentially attributable to glycemic control and the presence of comorbid conditions. These effects were spatially non-overlapping and the effects were not statistically related to one another. Further, several of the effects that were related to the presence of comorbidities were associated with behavioral performance, indicating progressive deficits in brain function with extended disease. These findings provide insight on the underlying neuropathology and may inform future treatment plans to curtail the neural impact of type 2 diabetes.

The effect of nonpharmaceutical weight-loss interventions in rural patients with diabetes: RE-POWER Diabetes.

OBJECTIVE: In this secondary analysis of the Rural Engagement in Primary Care for Optimizing Weight Reduction (RE-POWER) randomized trial, the authors determined the effectiveness of weight-loss interventions in people with diabetes compared with those without diabetes living in rural areas. METHODS: The RE-POWER study was a randomized trial designed to determine the effectiveness of nonpharmacological behavioral weight-loss interventions in rural participants with obesity, comparing the individual in-clinic visit model to in-person group sessions and phone group sessions over 24 months. In this secondary analysis, weight loss was compared in participants with and without diabetes. The effects of factors such as medications, insulin, and behavioral factors were compared. RESULTS: Participants with diabetes were less likely to lose weight during the study compared with those without diabetes up to 18 months (4.12% vs. 5.31%; net difference = 1.46%; 95% CI: 0.63%-2.28%). Participants with diabetes on insulin lost less weight than patients with diabetes not on insulin at 6 months (4.52% vs. 6.88%; net difference = 2.35%; 95% CI: 0.55%-4.16%). The group with diabetes had significantly lower changes in blood pressure and lipid parameters versus the group without diabetes. CONCLUSIONS: Patients with diabetes in rural areas were less likely to lose weight, and metabolic parameters were less responsive to weight loss, compared with patients without diabetes.

Islet Autoimmunity is Highly Prevalent and Associated With Diminished ß-Cell Function in Patients With Type 2 Diabetes in the Grade Study.

Islet autoimmunity may contribute to ß-cell dysfunction in type 2 diabetes (T2D). Its prevalence and clinical significance have not been rigorously determined. In this ancillary study to the Glycemia Reduction Approaches in Diabetes-A Comparative Effectiveness (GRADE) Study, we investigated the prevalence of cellular and humoral islet autoimmunity in patients with T2D duration 4·0±3·0 y, HbA1c 7·5±0·5% on metformin alone. We measured T cell autoreactivity against islet proteins, islet autoantibodies against GAD65, IA2, ZnT8, and ß-cell function. Cellular islet autoimmunity was present in 41·3%, humoral islet autoimmunity in 13·5%, and both in 5·3%. ß-cell function calculated as iAUC-CG and ΔC-peptide(0- 30)/Δglucose(0-30) from an oral glucose tolerance test was lower among T cell-positives (T+) than T cell-negatives (T-) using two different adjustments for insulin sensitivity (iAUC-CG: 13·2% [95% CI 0·3, 24·4%] or 11·4% [95% CI 0·4, 21·2%] lower; ΔC-peptide(0-30)/Δglucose(0-30)) 19% [95% CI 3·1, 32·3%] or 17·7% [95% CI 2·6, 30·5%] lower). T+ patients had 17% higher HbA1c (95% CI 0·07, 0·28) and 7·7 mg/dL higher fasting plasma glucose levels (95% CI 0·2,15·3) than T- patients. We conclude that islet autoimmunity is much more prevalent in T2D patients than previously reported. T cell-mediated autoimmunity is associated with diminished ß-cell function and worse glycemic control.

Testing the Psychometric Characteristics of the Revised Mastery of Stress Instrument in Adults With Type 2 Diabetes.

Background and Purpose: A promising, yet lengthy measure to identify mastery of patient-identified stress is Younger's (1991, 1993) Mastery of Stress Instrument (MSI). With a goal for a parsimonious and valid measure, this study determined the psychometric properties of a reduced item instrument with adults diagnosed with type 2 diabetes. Methods: First, an expert content analysis was completed. Second, item and confirmatory factor analysis were completed with a sample of 200 adults with a diagnosis of type 2 diabetes. Results: Eight items were removed through content validity and seven items were removed with Item analysis. Factor analysis supported Younger's four sub-concepts. Conclusions: Future research with this revised MSI scale is advocated to identify those who may need strategies to increase their mastery of stress.