Investigating the value of glucodensity analysis of continuous glucose monitoring data in type 1 diabetes: an exploratory analysis

Introduction

Continuous glucose monitoring (CGM) devices capture longitudinal data on interstitial glucose levels and are increasingly used to show the dynamics of diabetes metabolism. Given the complexity of CGM data, it is crucial to extract important patterns hidden in these data through efficient visualization and statistical analysis techniques.

Methods

In this paper, we adopted the concept of glucodensity, and using a subset of data from an ongoing clinical trial in pediatric individuals and young adults with new-onset type 1 diabetes, we performed a cluster analysis of glucodensities. We assessed the differences among the identified clusters using analysis of variance (ANOVA) with respect to residual pancreatic beta-cell function and some standard CGM-derived parameters such as time in range, time above range, and time below range.

Results

Distinct CGM data patterns were identified using cluster analysis based on glucodensities. Statistically significant differences were shown among the clusters with respect to baseline levels of pancreatic beta-cell function surrogate (C-peptide) and with respect to time in range and time above range.

Discussion

Our findings provide supportive evidence for the value of glucodensity in the analysis of CGM data. Some challenges in the modeling of CGM data include unbalanced data structure, missing observations, and many known and unknown confounders, which speaks to the importance of--and provides opportunities for--taking an approach integrating clinical, statistical, and data science expertise in the analysis of these data.

Diabetes Remission in the Alliance of Randomized Trials of Medicine Versus Metabolic Surgery in Type 2 Diabetes (ARMMS-T2D)

OBJECTIVE

The overall aim of the Alliance of Randomized Trials of Medicine versus Metabolic Surgery in Type 2 Diabetes (ARMMS-T2D) consortium is to assess the durability and longer-term effectiveness of metabolic surgery compared with medical/lifestyle management in patients with type 2 diabetes (NCT02328599).

RESEARCH DESIGN AND METHODS

A total of 316 patients with type 2 diabetes previously randomly assigned to surgery (N = 195) or medical/lifestyle therapy (N = 121) in the STAMPEDE, TRIABETES, SLIMM-T2D, and CROSSROADS trials were enrolled into this prospective observational cohort. The primary outcome was the rate of diabetes remission (hemoglobin A1c [HbA1c] ≤6.5% for 3 months without usual glucose-lowering therapy) at 3 years. Secondary outcomes included glycemic control, body weight, biomarkers, and comorbidity reduction.

RESULTS

Three-year data were available for 256 patients with mean 50 ± 8.3 years of age, BMI 36.5 ± 3.6 kg/m2, and duration of diabetes 8.8 ± 5.7 years. Diabetes remission was achieved in more participants following surgery than medical/lifestyle intervention (60 of 160 [37.5%] vs. 2 of 76 [2.6%], respectively; P < 0.001). Reductions in HbA1c (Δ = -1.9 ± 2.0 vs. -0.1 ± 2.0%; P < 0.001), fasting plasma glucose (Δ = -52 [-105, -5] vs. -12 [-48, 26] mg/dL; P < 0.001), and BMI (Δ = -8.0 ± 3.6 vs. -1.8 ± 2.9 kg/m2; P < 0.001) were also greater after surgery. The percentages of patients using medications to control diabetes, hypertension, and dyslipidemia were all lower after surgery (P < 0.001).

CONCLUSIONS

Three-year follow-up of the largest cohort of randomized patients followed to date demonstrates that metabolic/bariatric surgery is more effective and durable than medical/lifestyle intervention in remission of type 2 diabetes, including among individuals with class I obesity, for whom surgery is not widely used.

Insulin regulates arginine-stimulated insulin secretion in humans

AIMS

Insulin potentiates glucose-stimulated insulin secretion. These effects are attenuated in beta cell-specific insulin receptor knockout mice and insulin resistant humans. This investigation examines whether short duration insulin exposure regulates beta cell responsiveness to arginine, a non-glucose secretagogue, in healthy humans.

MATERIALS AND METHODS

Arginine-stimulated insulin secretion was studied in 10 healthy humans. In each subject arginine was administered as a bolus followed by continuous infusion on two occasions one month apart, after sham/saline or hyperinsulinemic-isoglycemic clamp, respectively providing low and high insulin pre-exposure conditions. Arginine-stimulated insulin secretion was measured by C-peptide deconvolution, and by a selective immunogenic (DAKO) assay for direct measurement of endogenous but not exogenous insulin.

RESULTS

Pre-exposure to exogenous insulin augmented arginine-stimulated insulin secretion. The effect was seen acutely following arginine bolus (endogenous DAKO insulin incremental AUC_240-255min 311.6 ± 208.1 (post-insulin exposure) versus 120.6 ± 42.2 μU/ml•min (sham/saline) (t-test P = 0.021)), as well as in response to continuous arginine infusion (DAKO insulin incremental AUC_260-290min 1095.3 ± 592.1 (sham/saline) versus 564.8 ± 207.1 μU/ml•min (high insulin)(P = 0.009)). Findings were similar when beta cell response was assessed using C-peptide, insulin secretion rates by deconvolution, and the C-peptide to glucose ratio.

CONCLUSIONS

We demonstrate a physiologic role of insulin in regulation of the beta cell secretory response to arginine.

LLF580, an FGF21 Analog, Reduces Triglycerides and Hepatic Fat in Obese Adults With Modest Hypertriglyceridemia

PURPOSE

To evaluate the safety and potential efficacy of LLF580, a genetically engineered variant of human fibroblast growth factor-21, for triglyceride lowering, weight loss, and hepatic fat reduction.

METHODS

A multicenter, double-blind, parallel design trial in obese, mildly hypertriglyceridemic adults randomized (1:1) to LLF580 300 mg or placebo subcutaneously every 4 weeks for 3 doses.

RESULTS

Of 64 randomized study participants, 61 (mean ± SD: age 45 ± 11 years, 49% male, 80/15/5% Caucasian/African American/other, body mass index 36.1 ± 3.8 kg/m2) received LLF580 (n = 30) or placebo (n = 31) at 7 research sites in the United States. LLF580 lowered serum triglycerides by 54% (least square mean placebo adjusted change from baseline), total cholesterol 7%, low-density lipoprotein cholesterol 12%, and increased high-density lipoprotein cholesterol 36% compared with placebo (all P < 0.001) over 12 weeks. Substantial reduction of liver fat of 52% over placebo (P < 0.001) was also demonstrated in the setting of improved liver function tests including alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase, the composite enhanced liver fibrosis score, and N-terminal type III collagen propeptide (all P < 0.05). Insulin and C-peptide levels and insulin resistance by homeostatic model assessment for insulin resistance were all lower, and adiponectin higher with LLF580 treatment compared with placebo, whereas fasting glucose and glycated hemoglobin were unchanged. Reductions in biomarkers of bone formation without differences in markers of bone resorption were observed. LLF580 was generally safe and well tolerated, except for higher incidence of generally mild to moderate gastrointestinal adverse effects.

CONCLUSIONS

In obese, mildly hypertriglyceridemic adults, LLF580 was generally safe and demonstrated beneficial effects on serum lipids, liver fat, and biomarkers of liver injury, suggesting it may be effective for treatment of select metabolic disorders including hypertriglyceridemia and nonalcoholic fatty liver disease. Assessments of longer term safety and efficacy are warranted.

CLINICALTRIALS.GOV IDENTIFIER

NCT03466203.

Risk of Cardiovascular Outcomes in Patients With Type 2 Diabetes After Addition of SGLT2 Inhibitors Versus Sulfonylureas to Baseline GLP-1RA Therapy

BACKGROUND

Several glucagon-like peptide receptor agonists (GLP-1RA) and sodium-glucose cotransporter-2 inhibitors (SGLT2i) have demonstrated cardiovascular benefit in type 2 diabetes in large randomized controlled trials in patients with established cardiovascular disease or multiple risk factors. However, few trial participants were on both agents, and it remains unknown whether the addition of SGLT2i to GLP-1RA therapy has further cardiovascular benefits.

METHODS

Patients adding either SGLT2i or sulfonylureas to baseline GLP-1RA were identified within 3 US claims datasets (2013-2018) and were 1:1 propensity score-matched, adjusting for >95 baseline covariates. The primary outcomes were a composite cardiovascular end point (comprising myocardial infarction, stroke, and all-cause mortality) and heart failure hospitalization. Adjusted hazard ratios (HRs) and 95% CIs were estimated in each dataset and pooled through fixed-effects meta-analysis.

RESULTS

Among 12 584 propensity score-matched pairs (mean [SD] age, 58.3 [10.9] years; 48.2% male) across the 3 datasets, there were 107 composite cardiovascular end point events (incidence rate per 1000 person-years, 9.9 [95% CI, 8.1-11.9]) among SGLT2i initiators compared with 129 events (incidence rate, 13.0 [95% CI, 10.9-15.3]) among sulfonylurea initiators, corresponding to an adjusted pooled HR of 0.76 (95% CI, 0.59-0.98); this decrease in composite cardiovascular end point was driven by numeric decreases in the risk of myocardial infarction (HR, 0.71 [95% CI, 0.51-1.003]) and all-cause mortality (HR, 0.68 [95% CI, 0.40-1.14]) but not stroke (HR, 1.05 [95% CI, 0.62-1.79]). For the outcome of heart failure hospitalization, there were 141 events (incidence rate, 13.0 [95% CI, 11.0-15.2]) among SGLT2i initiators versus 206 events (incidence rate, 20.8 [95% CI, 18.1-23.8]) among sulfonylurea initiators, corresponding to an adjusted pooled HR of 0.65 (95% CI, 0.50-0.82).

CONCLUSIONS

Risk of residual confounding cannot be fully excluded. Individual therapeutic agents within each class may have different magnitudes of effect. In this large real-world cohort of patients with diabetes already on GLP-1RA, addition of SGLT2i conferred greater cardiovascular benefit compared with addition of sulfonylurea. The magnitude of the cardiovascular risk reduction was comparable with the benefit seen in cardiovascular outcome trials of SGLT2i versus placebo, where baseline GLP-1RA use was minimal.

The presence of two reduced function variants in CYP2C9 influences the acute response to glipizide

AIMS

To examine whether the presence of two common missense variants in the CYP2C9 gene (rs1799853, encoding Arg144Cys and denoted as *2, and rs1057910, encoding Ile359Leu and denoted as *3) influences the acute physiological response to a single glipizide dose in individuals naïve to diabetes medications.

METHODS

In the Study to Understand the Genetics of the Acute Response to Metformin and Glipizide in Humans (SUGAR-MGH), 786 individuals genotyped for rs1799853/rs41291560 (*2) and rs1057910/rs9332214 (*3) were treated with 5 mg glipizide in the fasting state. Glucose and insulin levels were measured at baseline, 30, 60, 90, 120, 180 and 240 min for calculation of phenotypic endpoints of glipizide response. The challenge was aborted as a result of hypoglycaemia, defined as glucose <2.8 mmol/l or hypoglycaemia-related symptoms.

RESULTS

Carriers with two reduced function alleles had a 50% larger insulin area under the curve than carriers with zero or one copy (P=0.037), although this finding was primarily driven by an individual with a robust insulin response. In adjusted analyses, the risk of aborting the glipizide challenge was doubled in two-copy carriers (P=0.034). No significant findings were observed in glucose-based endpoints.

CONCLUSIONS

Carriers of two reduced function alleles in CYP2C9 may experience an increased insulin response to glipizide and be predisposed to a higher risk of hypoglycaemia, although no effect of genotype was seen in glucose-based measurements. Further studies are needed to clarify the utility of CYP2C9 genotyping to guide sulfonylurea treatment.

Serum Urate Lowering with Allopurinol and Kidney Function in Type 1 Diabetes

BACKGROUND

Higher serum urate levels are associated with an increased risk of diabetic kidney disease. Lowering of the serum urate level with allopurinol may slow the decrease in the glomerular filtration rate (GFR) in persons with type 1 diabetes and early-to-moderate diabetic kidney disease.

METHODS

In a double-blind trial, we randomly assigned participants with type 1 diabetes, a serum urate level of at least 4.5 mg per deciliter, an estimated GFR of 40.0 to 99.9 ml per minute per 1.73 m² of body-surface area, and evidence of diabetic kidney disease to receive allopurinol or placebo. The primary outcome was the baseline-adjusted GFR, as measured with iohexol, after 3 years plus a 2-month washout period. Secondary outcomes included the decrease in the iohexol-based GFR per year and the urinary albumin excretion rate after washout. Safety was also assessed.

RESULTS

A total of 267 patients were assigned to receive allopurinol and 263 to receive placebo. The mean age was 51.1 years, the mean duration of diabetes 34.6 years, and the mean glycated hemoglobin level 8.2%. The mean baseline iohexol-based GFR was 68.7 ml per minute per 1.73 m² in the allopurinol group and 67.3 ml per minute per 1.73 m² in the placebo group. During the intervention period, the mean serum urate level decreased from 6.1 to 3.9 mg per deciliter with allopurinol and remained at 6.1 mg per deciliter with placebo. After washout, the between-group difference in the mean iohexol-based GFR was 0.001 ml per minute per 1.73 m² (95% confidence interval [CI], -1.9 to 1.9; P = 0.99). The mean decrease in the iohexol-based GFR was -3.0 ml per minute per 1.73 m² per year with allopurinol and -2.5 ml per minute per 1.73 m² per year with placebo (between-group difference, -0.6 ml per minute per 1.73 m² per year; 95% CI, -1.5 to 0.4). The mean urinary albumin excretion rate after washout was 40% (95% CI, 0 to 80) higher with allopurinol than with placebo. The frequency of serious adverse events was similar in the two groups.

CONCLUSIONS

We found no evidence of clinically meaningful benefits of serum urate reduction with allopurinol on kidney outcomes among patients with type 1 diabetes and early-to-moderate diabetic kidney disease. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; PERL ClinicalTrials.gov number, NCT02017171.).

Impact of Acipimox Therapy on Free Fatty Acid Efflux and Endothelial Function in the Metabolic Syndrome: A Randomized Trial

OBJECTIVE

Insulin resistance is associated with increased lipolysis and elevated concentrations of free fatty acids (FFA), which in turn contribute to impaired vascular function. It was hypothesized that lowering FFA with acipimox, a nicotinic acid derivative that impairs FFA efflux, would improve endothelial function, measured by flow-mediated dilation (FMD), in individuals with metabolic syndrome.

METHODS

A total of 18 participants with metabolic syndrome and 17 healthy controls were enrolled and treated with acipimox 250 mg orally every 6 hours or placebo for 7 days in a randomized, double-blind, crossover trial.

RESULTS

Acipimox reduced FFA concentrations among individuals with metabolic syndrome to near normal levels (P = 0.01), but there was no change among healthy controls (P = 0.17). Acipimox did not improve endothelial-dependent FMD in either group (metabolic syndrome: P = 0.42; healthy controls: P = 0.16), although endothelial-independent nitroglycerin-mediated dilation among those with metabolic syndrome tended to increase (20.3%, P = 0.06). There were no changes in blood lipids or markers of inflammation following therapy. There was minimal correlation between change in FMD and baseline measures of BMI ( ρ = -0.09) or waist circumference ( ρ = -0.15).

CONCLUSIONS

In groups with normal or elevated baseline FFA, short-term reductions do not improve endothelial function assessed by FMD.

Preventing Early Renal Loss in Diabetes (PERL) Study: A Randomized Double-Blinded Trial of Allopurinol-Rationale, Design, and Baseline Data

OBJECTIVE

Higher serum uric acid (SUA) is associated with diabetic kidney disease (DKD). Preventing Early Renal Loss in Diabetes (PERL) evaluates whether lowering SUA with allopurinol slows glomerular filtration rate (GFR) loss in people with type 1 diabetes (T1D) and mild to moderate DKD. We present the PERL rationale, design, and baseline characteristics.

RESEARCH DESIGN AND METHODS

This double-blind, placebo-controlled, multicenter trial randomized 530 participants with T1D, estimated GFR (eGFR) of 40-99.9 mL/min/1.73 m², SUA ≥4.5 m/dL, and micro- to macroalbuminuric DKD or normoalbuminuria with declining kidney function (NDKF) (defined as historical eGFR decline ≥3 mL/min/1.73 m²/year) to allopurinol or placebo. The primary outcome is baseline-adjusted iohexol GFR (iGFR) after 3 years of treatment plus a 2-month washout period.

RESULTS

Participants are 66% male and 84% white. At baseline, median age was 52 years and diabetes duration was 35 years, 93% of participants had hypertension, and 90% were treated with renin-angiotensin system inhibitors (median blood pressure 127/71 mmHg). Median HbA_1c was 8%, SUA 5.9 mg/dL, iGFR 68 mL/min/1.73 m², and historical eGFR slope -3.5 mL/min/1.73 m²/year. Compared with participants with albuminuria (n = 419), those with NDKF (n = 94) were significantly older (56 vs. 52 years), had lower HbA_1c (7.7 vs. 8.1%) and SUA (5.4 vs. 6.0 mg/dL), and had higher eGFR (82 vs. 74 mL/min/1.73 m²) and historical eGFR loss (-4.7 vs. -2.5 mL/min/1.73 m²/year). These differences persisted when comparing groups with similar rates of historical eGFR loss.

CONCLUSIONS

PERL will determine the effect of allopurinol on mild to moderate DKD in T1D, with or without albuminuria. Participants with normoalbuminuria and rapid GFR loss manifested many DKD risk factors of those with albuminuria, but with less severity.

Plasma FGF-19 Levels are Increased in Patients with Post-Bariatric Hypoglycemia

BACKGROUND

Hypoglycemia is an increasingly recognized complication of bariatric surgery. Mechanisms contributing to glucose lowering remain incompletely understood. We aimed to identify differentially abundant plasma proteins in patients with post-bariatric hypoglycemia (PBH) after Roux-en-Y gastric bypass (RYGB), compared to asymptomatic post-RYGB.

METHODS

Proteomic analysis of blood samples collected after overnight fast and mixed meal challenge in individuals with PBH, asymptomatic RYGB, severe obesity, or overweight recruited from outpatient hypoglycemia or bariatric clinics.

RESULTS

The top-ranking differentially abundant protein at 120 min after mixed meal was fibroblast growth factor 19 (FGF-19), an intestinally derived hormone regulated by bile acid-FXR signaling; levels were 2.4-fold higher in PBH vs. asymptomatic post-RYGB (mean + SEM, 1094 ± 141 vs. 428 ± 45, P < 0.001, FDR < 0.01). FGF-19 ELISA confirmed 3.5-fold higher concentrations in PBH versus asymptomatic (360 ± 70 vs. 103 ± 18, P = 0.025). To explore potential links between increased FGF-19 and GLP-1, residual samples from other human studies in which GLP-1 was modulated were assayed. FGF-19 levels did not change in response to infusion of GLP-1 and PYY in overweight/obese individuals. Infusion of the GLP-1 receptor antagonist exendin 9-39 in recently operated asymptomatic post-RYGB did not alter FGF-19 levels after mixed meal. By contrast, GLP-1 receptor antagonist infusion yielded a significant increase in FGF-19 levels after oral glucose in individuals with PBH. While plasma bile acids did not differ between PBH and asymptomatic post-RYGB, these data suggest unique interrelationships between GLP-1 and FGF-19 in PBH.

CONCLUSIONS

Taken together, these data support FGF-19 as a potential contributor to insulin-independent pathways driving postprandial hypoglycemia in PBH.

Adjustable gastric band surgery or medical management in patients with type 2 diabetes and obesity: three-year results of a randomized trial

BACKGROUND

Few randomized trials have compared surgical versus lifestyle and pharmacologic approaches for type 2 diabetes (T2D) patients with mild to moderate obesity.

OBJECTIVES

This study examined resolution of hyperglycemia (A1C <6.5% and fasting glucose <126 mg/dL) 3 years after randomization to either a laparoscopic adjustable gastric band (LAGB) or 1-year diabetes and weight management (DWM) program.

SETTING

University medical center, United States.

METHODS

Forty T2D patients (mean ± SD: age, 51.3 ±10.0 yr; weight 109.5 ± 15.0 kg; body mass index [BMI] 36.5 ± 3.7 kg/m²; HBA1C 8.2% ± 1.2%) were randomized to LAGB (n = 18) or DWM (n = 22).

RESULTS

At 3 years, 13% of 16 patients in LAGB and 5% of 17 patients in DWM achieved resolution of hyperglycemia (P = .601), with a modestly greater reduction in antidiabetic medications in the surgical group (P = .054). Reductions from baseline in A1C were sustained at 3 years in LAGB (-.82% [95% CI: -1.62 to -.01], P = .046) compared with DWM (+.23% [95% CI: -.57 to 1.03], P = .567). The surgical group had greater weight loss (-12.0 kg [95% CI: -15.9 to -8.1] versus -4.8 [95% CI: -8.6 to -.9], P = .010). HDL-cholesterol increased more after surgery (P = .003), but changes in triglycerides, LDL-cholesterol, and blood pressure did not differ between treatments. Diabetes- and obesity-specific quality of life improved comparably with both therapies.

CONCLUSIONS

Achievement of American Diabetes Association targets for glucose, lipids, and blood pressure was similar with both treatment strategies. LAGB leads to greater sustained weight loss and higher HDL cholesterol compared with a DWM program. These findings may help guide patients with T2D and obesity when exploring options for diabetes and weight management.

PET-CT reveals increased intestinal glucose uptake after gastric surgery

BACKGROUND

Mechanisms of metabolic improvement after bariatric surgery remain incompletely understood. Intestinal glucose uptake is increased after gastric bypass in rodents, potentially contributing to reduced blood glucose and type 2 diabetes remission.

OBJECTIVE

We assessed whether intestinal glucose uptake is increased in humans after gastric surgery.

SETTING

University Hospital, United States.

METHODS

In a retrospective, case-control cohort study, positron emission tomography-computerized tomography scans performed for clinical indications were analyzed to quantify intestinal glucose uptake in patients with or without history of gastric surgery. We identified 19 cases, defined as patients over age 18 with prior gastric surgery (Roux-en-Y gastric bypass [n = 10], sleeve gastrectomy [n = 1], or Billroth I [n = 2] or II gastrectomy [n = 6]), and 43 controls without gastric surgery, matched for age, sex, and indication for positron emission tomography-computerized tomography. Individuals with gastrointestinal malignancy or metformin treatment were excluded. Images were obtained 60 minutes after ¹⁸F-fluorodeoxyglucose injection (4.2 MBq/kg), and corrected by attenuation; noncontrast low-dose computerized tomography was obtained in parallel. Fused and nonfused images were analyzed; standardized uptake values were calculated for each region by volumes of interest at the region of highest activity.

RESULTS

Both standardized uptake values maximum and mean were significantly increased by 41% to 98% in jejunum, ascending, and transverse colon in patients with prior gastric surgery (P < .05 versus controls).

CONCLUSION

Intestinal glucose uptake is increased in patients with prior gastric surgery. Prospective studies are important to dissect the contributions of weight loss, dietary factors, and systemic metabolism, and to determine the relationship with increased insulin-independent glucose uptake and reductions in glycemia.

Effect of Targeting Inflammation With Salsalate: The TINSAL-CVD Randomized Clinical Trial on Progression of Coronary Plaque in Overweight and Obese Patients Using Statins

IMPORTANCE

Inflammation may contribute to pathological associations among obesity, diabetes mellitus, and cardiovascular disease.

OBJECTIVE

To determine whether targeting inflammation using salsalate compared with placebo reduces progression of noncalcified coronary artery plaque.

DESIGN, SETTING, AND PARTICIPANTS

In the Targeting Inflammation Using Salsalate in Cardiovascular Disease (TINSAL-CVD) trial participants were randomly assigned between September 23, 2008, and July 5, 2012, to 30 months of salsalate or placebo in addition to standard, guideline-based therapies. Randomization was computerized and centrally allocated, with patients, health care professionals, and researchers masked to treatment assignment. Participants were overweight and obese statin-using patients with established, stable coronary heart disease.

INTERVENTIONS

Salsalate (3.5 g/d) or placebo orally over 30 months.

MAIN OUTCOMES AND MEASURES

The primary outcome was progression of noncalcified coronary artery plaque assessed by multidetector computed tomographic angiography. Secondary outcomes were other measures of safety and efficacy.

RESULTS

Two hundred fifty-seven participants were randomized to salsalate (n = 129) or placebo (n = 128). Their mean (SD) age was 60.8 (7.0) years, and 94.0% (236 of 251) were male. One hundred ninety participants (89 in the salsalate group and 101 in the placebo group) completed the study. Compared with baseline, there was no increase in noncalcified plaque volume in the placebo-treated patients and no difference in change between the salsalate and placebo groups (mean difference, -1 mm3; 95% CI, -11 to 9 mm3; P = .87). Salsalate treatment decreased total white blood cell, lymphocyte, monocyte, and neutrophil counts and increased adiponectin levels without change in C-reactive protein levels. Fasting glucose, triglycerides, uric acid, and bilirubin levels were decreased in the salsalate group compared with the placebo group, while hemoglobin levels were increased. Urinary albumin levels increased, with tinnitus and atrial arrhythmias more common, in the salsalate group compared with the placebo group.

CONCLUSIONS AND RELEVANCE

Salsalate when added to current therapies that include a statin does not reduce progression of noncalcified coronary plaque volume assessed by multidetector computed tomographic angiography in statin-using patients with established, stable coronary heart disease. The absence of progression of noncalcified plaque volume in the placebo group may limit interpretation of the trial results.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00624923.

Metabolic Effects of Betaine: A Randomized Clinical Trial of Betaine Supplementation in Prediabetes

CONTEXT

Plasma betaine correlates with insulin sensitivity in humans. Betaine supplementation improves metabolic effects in mice fed a high-fat diet.

OBJECTIVE

To assess metabolic effects of oral betaine in obese participants with prediabetes.

DESIGN

A 12-week, parallel arm, randomized, double-masked, placebo-controlled trial.

SETTING

University-affiliated hospital.

PARTICIPANTS AND INTERVENTIONS

Persons with obesity and prediabetes (N = 27) were randomly assigned to receive betaine 3300 mg orally twice daily for 10 days, then 4950 mg twice daily for 12 weeks, or placebo.

MAIN OUTCOME MEASURES

Changes from baseline in insulin sensitivity, glycemia, hepatic fat, and endothelial function.

RESULTS

There was a 16.5-fold increase in plasma dimethylglycine [dimethylglycine (DMG); P < 0.0001] levels, but modest 1.3- and 1.5-fold increases in downstream serine and methionine levels, respectively, in the betaine vs placebo arm. Betaine tended to reduce fasting glucose levels (P = 0.08 vs placebo) but had no other effect on glycemia. Insulin area under curve after oral glucose was reduced for betaine treatment compared with placebo (P = 0.038). Insulin sensitivity, assessed by euglycemic hyperinsulinemic clamp, was not improved. Serum total cholesterol levels increased after betaine treatment compared with placebo (P = 0.032). There were no differences in change in intrahepatic triglyceride or endothelial function between groups.

CONCLUSION

DMG accumulation supports DMG dehydrogenase as rate limiting for betaine metabolism in persons with prediabetes. Betaine had little metabolic effect. Additional studies may elucidate mechanisms contributing to differences between preclinical and human responses to betaine, and whether supplementation of metabolites downstream of DMG improves metabolism.

Clinical and Patient-Centered Outcomes in Obese Patients With Type 2 Diabetes 3 Years After Randomization to Roux-en-Y Gastric Bypass Surgery Versus Intensive Lifestyle Management: The SLIMM-T2D Study

OBJECTIVE

To compare the effect of Roux-en-Y gastric bypass (RYGB) surgery versus intensive medical diabetes and weight management (IMWM) on clinical and patient-reported outcomes in obese patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

We prospectively randomized 38 obese patients with type 2 diabetes (15 male and 23 female, with mean ± SD weight 104 ± 16 kg, BMI 36.3 ± 3.4 kg/m², age 52 ± 6 years, and HbA_1c 8.5 ± 1.3% [69 ± 14 mmol/mol]) to laparoscopic RYGB (n = 19) or IMWM (n = 19). Changes in weight, HbA_1c, cardiovascular risk factors (UKPDS risk engine), and self-reported health status (the 36-Item Short-Form [SF-36] survey, Impact of Weight on Quality of Life [IWQOL] instrument, and Problem Areas in Diabetes Survey [PAID]) were assessed.

RESULTS

After 3 years, the RYGB group had greater weight loss (mean -24.9 kg [95% CI -29.5, -20.4] vs. -5.2 [-10.3, -0.2]; P < 0.001) and lowering of HbA_1c (-1.79% [-2.38, -1.20] vs. -0.39% [-1.06, 0.28] [-19.6 mmol/mol {95% CI -26.0, -13.1} vs. -4.3 {-11.6, 3.1}]; P < 0.001) compared with the IMWM group. Changes in cardiometabolic risk for coronary heart disease and stroke were all more favorable in RYGB versus IMWM (P < 0.05 to P < 0.01). IWQOL improved more after RYGB (P < 0.001), primarily due to subscales of physical function, self-esteem, and work performance. SF-36 and PAID scores improved in both groups, with no difference between treatments. A structural equation model demonstrated that improvement in overall quality of life was more strongly associated with weight loss than with improved HbA_1c and was manifest by greater improvements in IWQOL than with either SF-36 or PAID.

CONCLUSIONS

Three years after randomization to RYGB versus IMWM, surgery produced greater weight loss, lower HbA_1c, reduced cardiovascular risk, and improvements in obesity-related quality of life in obese patients with type 2 diabetes.

Cardiovascular outcomes associated with canagliflozin versus other non-gliflozin antidiabetic drugs: population based cohort study

OBJECTIVE

To evaluate the cardiovascular safety of canagliflozin, a sodium-glucose cotransporter 2 inhibitor for the treatment of type 2 diabetes mellitus, in direct comparisons with DPP-4 inhibitors (DPP-4i), GLP-1 receptor agonists (GLP-1RA), or sulfonylureas, as used in routine practice.

DESIGN

Population based retrospective cohort study.

SETTING

Nationwide sample of patients with type 2 diabetes from a large de-identified US commercial healthcare database (Optum Clinformatics Datamart).

PARTICIPANTS

Three pairwise 1:1 propensity score matched cohorts of patients with type 2 diabetes 18 years and older who initiated canagliflozin or a comparator non-gliflozin antidiabetic agent (ie, a DPP-4i, a GLP-1RA, or a sulfonylurea) between April 2013 and September 2015.

MAIN OUTCOME MEASURES

The primary outcomes were heart failure admission to hospital and a composite cardiovascular endpoint (comprised of being admitted to hospital for acute myocardial infarction, ischemic stroke, or hemorrhagic stroke). Hazard ratios and 95% confidence intervals were estimated in each propensity score matched cohort controlling for more than 100 baseline characteristics.

RESULTS

During a 30 month period, the hazard ratio for heart failure admission to hospital associated with canagliflozin was 0.70 (95% confidence interval 0.54 to 0.92) versus a DPP-4i (n=17 667 pairs), 0.61 (0.47 to 0.78) versus a GLP-1RA (20 539), and 0.51 (0.38 to 0.67) versus a sulfonylurea (17 354 ). The hazard ratio for the composite cardiovascular endpoint associated with canagliflozin was 0.89 (0.68 to 1.17) versus a DPP-4i, 1.03 (0.79 to 1.35) versus a GLP-1RA, and 0.86 (0.65 to 1.13) versus a sulfonylurea. Results were similar in sensitivity analyses further adjusting for baseline hemoglobin A1c levels and in subgroups of patients with and without prior cardiovascular disease or heart failure.

CONCLUSIONS

In this large cohort study, canagliflozin was associated with a lower risk of heart failure admission to hospital and with a similar risk of myocardial infarction or stroke in direct comparisons with three different classes of non-gliflozin diabetes treatment alternatives as used in routine care.

Design and Clinical Evaluation of a Novel Low-Glucose Prediction Algorithm with Mini-Dose Stable Glucagon Delivery in Post-Bariatric Hypoglycemia

BACKGROUND

Postbariatric hypoglycemia (PBH) is a complication of bariatric surgery with limited therapeutic options. We developed an event-based system to predict and detect hypoglycemia based on continuous glucose monitor (CGM) data and recommend delivery of minidose liquid glucagon.

METHODS

We performed an iterative development clinical study employing a novel glucagon delivery system: a Dexcom CGM connected to a Windows tablet running a hypoglycemia prediction algorithm and an Omnipod pump filled with an investigational stable liquid glucagon formulation. Meal tolerance testing was performed in seven participants with PBH and history of neuroglycopenia. Glucagon was administered when hypoglycemia was predicted. Primary outcome measures included the safety and feasibility of this system to predict and prevent severe hypoglycemia. Secondary outcomes included hypoglycemia prediction by the prediction algorithm, minimization of time below hypoglycemia threshold using glucagon, and prevention of rebound hyperglycemia.

RESULTS

The hypoglycemia prediction algorithm alerted for impending hypoglycemia in the postmeal state, prompting delivery of glucagon (150 μg). After observations of initial incomplete efficacy to prevent hypoglycemia in the first two participants, system modifications were implemented: addition of PBH-specific detection algorithm, increased glucagon dose (300 μg), and a second glucagon dose if needed. These modifications, together with rescue carbohydrates provided to some participants, contributed to progressive improvements in glucose time above the hypoglycemia threshold (75 mg/dL).

CONCLUSIONS

Preliminary results indicate that our event-based automatic monitoring algorithm successfully predicted likely hypoglycemia. Minidose glucagon therapy was well tolerated, without prolonged or severe hypoglycemia, and without rebound hyperglycemia.

Salsalate improves glycaemia in overweight persons with diabetes risk factors of stable statin-treated cardiovascular disease: A 30-month randomized placebo-controlled trial

OBJECTIVE

To assess long-term efficacy and safety of salsalate to improve glycemia in persons with diabetes risk, who are overweight with statin-treated, stable coronary heart disease.

METHODS

Glycemic status was assessed in 192 persons without diabetes at baseline in a pre-specified secondary analysis from Targeting INflammation Using SALsalate in CardioVascular Disease (TINSAL-CVD), a multi-center, double-masked, randomized (1:1), placebo-controlled, parallel clinical trial.

RESULTS

Participants were mostly Caucasian males, age 60±7 years, BMI 31.4±3.0 kg/m² , fasting glucose 92.8±11.0 mg/dL, and HbA1c 5.8±0.3%. Reductions in mean fasting glucose -5.70 mg/dL (95%CI: -7.44 to -3.97 mg/dL, P<0.001), HbA1c -0.11% (95%CI: -0.210 to -0.002%, P=0.046) and glycated serum protein -81.8 μg/mL (95%CI: -93.7 to -69.9 μg/mL, P<0.001) were demonstrated in salsalate compared to placebo-assigned groups over 30 months. Reductions in fasting glucose and glycated serum protein were greater with salsalate compared to placebo in participants with prediabetes compared to a normoglycemic sub-group (P_interaction =0.018). Salsalate lowered total white blood cell counts (mean difference -0.7x10³ /μL, 95%CI: -1.0 to -0.4 x10³ /μL, P<0.001) and increased adiponectin (mean difference 1.8 μg/mL, 95%CI: 0.9 to 2.6 μg/mL, P<0.001) and albuminurea (16.7 μg/mg, 95%CI: 6.4 to 27.1 μg/mg, P<0.001) compared to placebo, consistent with previous results for patients with type 2 diabetes taking salsalate for shorter times.

CONCLUSIONS

Salsalate improves glycemia in obese persons at increased risk for diabetes, and hence may decrease risk of incident type 2 diabetes. Salsalate may inform new therapeutic approaches for diabetes prevention, but renal safety may limit clinical utility.

Heterogeneity of proliferative markers in pancreatic β-cells of patients with severe hypoglycemia following Roux-en-Y gastric bypass

AIMS

Severe postprandial hypoglycemia with neuroglycopenia is an increasingly recognized, debilitating complication of Roux-en-Y gastric bypass (RYGB) surgery. Increased secretion of insulin and incretin hormones is implicated in its pathogenesis. Histopathologic examination of pancreas has demonstrated increased islet size and/or nuclear diameter in post-RYGB patients who underwent pancreatectomy for severe refractory hypoglycemia with neuroglycopenia (RYGB + NG). We aimed to determine whether β-cell proliferation or apoptosis is altered in RYGB + NG.

METHODS

We performed an observational study to analyze markers of proliferation, apoptosis, cell cycle, and transcription factor expression in pancreatic tissue from affected RYGB + NG patients (n = 12), normoglycemic patients undergoing pancreatic surgery for benign lesions (controls, n = 6), and individuals with hypoglycemia due to insulinoma (n = 52).

RESULTS

Proliferative cell nuclear antigen (PCNA) expression was increased in insulin-positive cells in RYGB + NG patients (4.5-fold increase, p < 0.001 vs. controls) and correlated with β-cell mass. Ki-67 immunoreactivity was low in both RYGB + NG and controls, but did not differ between groups. Phospho-histone H3 levels did not differ between RYGB + NG and controls. PCNA and Ki-67 were both significantly lower in both controls and RYGB + NG than insulinomas. Markers of apoptosis and cell cycle (M30, p27, and p21) did not differ between groups. PDX1 and menin exhibited similar expression patterns, while FOXO1 appeared to be more cytosolic in RYGB + NG.

CONCLUSIONS

Markers of proliferation are heterogeneous in patients with severe post-RYGB hypoglycemia. Increased β-cell proliferation in some individuals may contribute to increased β-cell mass observed in severely affected patients.

Therapeutic approaches targeting inflammation for diabetes and associated cardiovascular risk

Obesity-related sub-acute chronic inflammation has been associated with incident type 2 diabetes and atherosclerotic cardiovascular disease. Inflammation is increasingly considered to be a pathologic mediator of these commonly co-occurring diseases. A growing number of preclinical and clinical studies support the inflammatory hypothesis, but clinical trials to confirm the therapeutic potential to target inflammation to treat or prevent cardiometabolic conditions are still ongoing. There are multiple inflammatory signaling pathways. Regulation is complex, with substantial crosstalk across these multiple pathways. The activity of select pathways may be differentially regulated in different tissues. Pharmacologic approaches to diabetes management may have direct or indirect antiinflammatory effects, the latter potentially attributable to an improved metabolic state. Conversely, some antiinflammatory approaches may affect glucose metabolism and cardiovascular health. To date, clinical trials suggest that targeting one portion of the inflammatory cascade may differentially affect dysglycemia and atherothrombosis. Understanding the underlying biological processes may contribute to the development of safe and effective therapies, although a single approach may not be sufficient for optimal management of both metabolic and athrothrombotic disease states.

Physical Activity in Obese Type 2 Diabetes After Gastric Bypass or Medical Management

BACKGROUND

The purpose of this study was to compare effects of Roux-en-Y gastric bypass versus a multidisciplinary, group-based medical diabetes and weight management program on physical fitness and behaviors.

METHODS

Physical behavior and fitness were assessed in participants of the study Surgery or Lifestyle With Intensive Medical Management in the Treatment of Type 2 Diabetes (SLIMM-T2D) (NCT01073020), a randomized, parallel-group trial conducted at a US academic hospital and diabetes clinic with 18- to 24-month follow-up. Thirty-eight type 2 diabetes patients with hemoglobin A_1c ≥6.5% and body mass index 30-42 kg/m² were randomized to Roux-en-Y gastric bypass or the medical program. A 6-minute walk test to evaluate fitness, self-reported physical activity, standardized physical surveys, and cardiometabolic risk assessment were performed at baseline and after intervention.

RESULTS

Both groups similarly improved 6-minute walk test distance, with greater improvements in oxygen saturation and reduced heart rate after surgery. Self-reported physical activity improved similarly at 18-24 months after interventions, although exercise increased gradually after surgery, whereas early substantial increases in the medical group were not fully sustained. Self-reported total and physical health were similar by Short Form-36 but improved more in the Impact of Weight on Quality of Life survey after surgery. Improvement in cardiovascular risk scores, HbA_1c, and body mass index were greater after surgery.

CONCLUSION

In this small, randomized study, both interventions led to therapeutic lifestyle changes and improved objective and self-reported physical fitness. Greater improvements in heart rate, oxygen saturation, and perceived impact of weight on health were seen after surgery, which could be attributable to greater weight loss. The clinical importance of these improvements with greater weight loss warrants further investigation.

Ebselen does not improve oxidative stress and vascular function in patients with diabetes: a randomized, crossover trial

Oxidative stress is a key driver of vascular dysfunction in diabetes mellitus. Ebselen is a glutathione peroxidase mimetic. A single-site, randomized, double-masked, placebo-controlled, crossover trial was carried out in 26 patients with type 1 or type 2 diabetes to evaluate effects of high-dose ebselen (150 mg po twice daily) administration on oxidative stress and endothelium-dependent vasodilation. Treatment periods were in random order of 4 wk duration, with a 4-wk washout between treatments. Measures of oxidative stress included nitrotyrosine, plasma 8-isoprostanes, and the ratio of reduced to oxidized glutathione. Vascular ultrasound of the brachial artery and plethysmographic measurement of blood flow were used to assess flow-mediated and methacholine-induced endothelium-dependent vasodilation of conduit and resistance vessels, respectively. Ebselen administration did not affect parameters of oxidative stress or conduit artery or forearm arteriolar vascular function compared with placebo treatment. There was no difference in outcome by diabetes type. Ebselen, at the dose and duration evaluated, does not improve the oxidative stress profile, nor does it affect endothelium-dependent vasodilation in patients with diabetes mellitus.

Defects in muscle branched-chain amino acid oxidation contribute to impaired lipid metabolism

OBJECTIVE

Plasma levels of branched-chain amino acids (BCAA) are consistently elevated in obesity and type 2 diabetes (T2D) and can also prospectively predict T2D. However, the role of BCAA in the pathogenesis of insulin resistance and T2D remains unclear.

METHODS

To identify pathways related to insulin resistance, we performed comprehensive gene expression and metabolomics analyses in skeletal muscle from 41 humans with normal glucose tolerance and 11 with T2D across a range of insulin sensitivity (SI, 0.49 to 14.28). We studied both cultured cells and mice heterozygous for the BCAA enzyme methylmalonyl-CoA mutase (Mut) and assessed the effects of altered BCAA flux on lipid and glucose homeostasis.

RESULTS

Our data demonstrate perturbed BCAA metabolism and fatty acid oxidation in muscle from insulin resistant humans. Experimental alterations in BCAA flux in cultured cells similarly modulate fatty acid oxidation. Mut heterozygosity in mice alters muscle lipid metabolism in vivo, resulting in increased muscle triglyceride accumulation, increased plasma glucose, hyperinsulinemia, and increased body weight after high-fat feeding.

CONCLUSIONS

Our data indicate that impaired muscle BCAA catabolism may contribute to the development of insulin resistance by perturbing both amino acid and fatty acid metabolism and suggest that targeting BCAA metabolism may hold promise for prevention or treatment of T2D.

Comparative cardiovascular safety of glucagon-like peptide-1 receptor agonists versus other antidiabetic drugs in routine care: a cohort study

AIMS

To evaluate the comparative cardiovascular disease (CVD) safety of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) in head-to-head comparisons with dipeptidyl peptidase-4 (DPP-4) inhibitors, sulphonylureas or insulin, when added to metformin, as used in 'real-world' patients with type 2 diabetes mellitus (T2DM).

METHODS

Within a large US commercial health plan database linked to laboratory test results, we identified three pairwise 1 : 1 propensity-score-matched cohorts of patients with T2DM aged ≥18 years treated with metformin who initiated a GLP-1 RA or a comparator, i.e. DPP-4 inhibitor (n = 35 534), second-generation sulphonylureas (n = 28 138) or insulin (n = 47 068), between 2005 and 2013. We examined the association between drug initiation and a composite CVD endpoint, comprising hospitalizations for acute myocardial infarction, unstable angina, stroke or coronary revascularization.

RESULTS

During the course of 1 year, there were 13.9 and 13.7 CVD events per 1000 person-years among propensity-score-matched initiators of GLP-1 RAs versus DPP-4 inhibitors [hazard ratio (HR) 1.02; 95% confidence interval (CI) 0.84-1.24]; and 12.1 versus 14.0 events among initiators of GLP-1 RAs versus sulphonylureas (HR 0.86; 95% CI 0.69-1.08). The effect estimates for GLP-1 RAs versus insulin were sensitive to the adjustment for glycated haemoglobin, after which the HR was 1.01 (95% CI 0.73-1.41). Results were robust across several sensitivity analyses, including an as-treated analysis considering up to 8.7 years of follow-up.

CONCLUSIONS

This large study, performing head-to-head comparisons of GLP-1 RAs with other antidiabetic agents in real-world patients, provides estimates of relative safety precise enough to exclude large differences in CVD risk and adds further understanding to results from recent clinical trials.

Clinical Update: Cardiovascular Disease in Diabetes Mellitus: Atherosclerotic Cardiovascular Disease and Heart Failure in Type 2 Diabetes Mellitus - Mechanisms, Management, and Clinical Considerations

Cardiovascular disease remains the principal cause of death and disability among patients with diabetes mellitus. Diabetes mellitus exacerbates mechanisms underlying atherosclerosis and heart failure. Unfortunately, these mechanisms are not adequately modulated by therapeutic strategies focusing solely on optimal glycemic control with currently available drugs or approaches. In the setting of multifactorial risk reduction with statins and other lipid-lowering agents, antihypertensive therapies, and antihyperglycemic treatment strategies, cardiovascular complication rates are falling, yet remain higher for patients with diabetes mellitus than for those without. This review considers the mechanisms, history, controversies, new pharmacological agents, and recent evidence for current guidelines for cardiovascular management in the patient with diabetes mellitus to support evidence-based care in the patient with diabetes mellitus and heart disease outside of the acute care setting.

Evaluating the Cardiovascular Safety of New Medications for Type 2 Diabetes: Time to Reassess?

The U.S. Food and Drug Administration (FDA) issued a Guidance for Industry in 2008 defining preapproval and postapproval requirements for the demonstration of cardiovascular safety for all new medications developed for glycemic management in type 2 diabetes. Seventeen large, prospective, randomized, controlled clinical trials involving more than 140,000 subjects thus far have been completed or are ongoing in accordance with this guidance. All five of the completed trials, involving three different drug classes, have met their primary objective to exclude an unacceptable level of ischemic cardiovascular risk as defined in the FDA guidance. Additionally, one trial found an increased risk of hospitalization for heart failure, and another demonstrated decreases in cardiovascular mortality and hospitalization for heart failure. Given that a heightened risk of cardiovascular ischemic events has not been demonstrated across several classes of new diabetes drugs, we believe it is time for the scientific community and the FDA to consider a more targeted approach to what is, in effect, a global cardiovascular safety trial requirement for all new type 2 diabetes medications in development.

Dietary Betaine Supplementation Increases Fgf21 Levels to Improve Glucose Homeostasis and Reduce Hepatic Lipid Accumulation in Mice

Identifying markers of human insulin resistance may permit development of new approaches for treatment and prevention of type 2 diabetes. To this end, we analyzed the fasting plasma metabolome in metabolically characterized human volunteers across a spectrum of insulin resistance. We demonstrate that plasma betaine levels are reduced in insulin-resistant humans and correlate closely with insulin sensitivity. Moreover, betaine administration to mice with diet-induced obesity prevents the development of impaired glucose homeostasis, reduces hepatic lipid accumulation, increases white adipose oxidative capacity, and enhances whole-body energy expenditure. In parallel with these beneficial metabolic effects, betaine supplementation robustly increased hepatic and circulating fibroblast growth factor (Fgf)21 levels. Betaine administration failed to improve glucose homeostasis and liver fat content in Fgf21(-/-) mice, demonstrating that Fgf21 is necessary for betaine's beneficial effects. Together, these data indicate that dietary betaine increases Fgf21 levels to improve metabolic health in mice and suggest that betaine supplementation merits further investigation as a supplement for treatment or prevention of type 2 diabetes in humans.

Effects of Gastric Bypass and Gastric Banding on Bone Remodeling in Obese Patients With Type 2 Diabetes

CONTEXT

Roux-en-Y gastric bypass (RYGB) leads to high-turnover bone loss, but little is known about skeletal effects of laparoscopic adjustable gastric banding (LAGB) or mechanisms underlying bone loss after bariatric surgery.

OBJECTIVE

To evaluate effects of RYGB and LAGB on fasting and postprandial indices of bone remodeling.

DESIGN AND SETTING

Ancillary investigation of a prospective study at 2 academic institutions.

PARTICIPANTS

Obese adults aged 21-65 years with type 2 diabetes who underwent RYGB (n = 11) or LAGB (n = 8).

OUTCOMES

Serum C-terminal telopeptide (CTX), procollagen type 1 N-terminal propeptide (P1NP), and PTH were measured during a mixed meal tolerance test at baseline, 10 days and 1 year after surgery. Changes in 25-hydroxyvitamin D, polypeptide YY (PYY), glucagon-like peptide-1, glucose-dependent insulinotropic peptide, and insulin were also assessed.

RESULTS

Fasting CTX increased 10 days after RYGB but not LAGB (+69 ± 23% vs +12±12%, P < .001), despite comparable weight loss at that time. By 1 year, fasting CTX and P1NP increased more after RYGB than LAGB (CTX +221 ± 60% vs +15 ± 6%, P<0.001; P1NP +93 ± 25% vs -9 ± 10%, P < .001) and weight loss was greater with RYGB. Changes in CTX were independent of PTH and 25-hydroxyvitamin D but were associated with increases in fasting PYY. Postprandial suppression of CTX was more pronounced after RYGB than LAGB at 10 days and 1 year postoperatively.

CONCLUSIONS

RYGB is accompanied by early increases in fasting indices of bone remodeling, independent of weight loss or changes in PTH or 25-hydroxyvitamin D. LAGB did not affect bone markers. PYY and other enterohormonal signals may play a role in RYGB-specific skeletal changes.

SerpinB1 Promotes Pancreatic β Cell Proliferation

Although compensatory islet hyperplasia in response to insulin resistance is a recognized feature in diabetes, the factor(s) that promote β cell proliferation have been elusive. We previously reported that the liver is a source for such factors in the liver insulin receptor knockout (LIRKO) mouse, an insulin resistance model that manifests islet hyperplasia. Using proteomics we show that serpinB1, a protease inhibitor, which is abundant in the hepatocyte secretome and sera derived from LIRKO mice, is the liver-derived secretory protein that regulates β cell proliferation in humans, mice, and zebrafish. Small-molecule compounds, that partially mimic serpinB1 effects of inhibiting elastase activity, enhanced proliferation of β cells, and mice lacking serpinB1 exhibit attenuated β cell compensation in response to insulin resistance. Finally, SerpinB1 treatment of islets modulated proteins in growth/survival pathways. Together, these data implicate serpinB1 as an endogenous protein that can potentially be harnessed to enhance functional β cell mass in patients with diabetes.

Risk of Type 2 Diabetes Is Lower in US Adults Taking Chromium-Containing Supplements

BACKGROUND

Dietary supplement use is widespread in the United States. Although it has been suggested in both in vitro and small in vivo human studies that chromium has potentially beneficial effects in type 2 diabetes (T2D), chromium supplementation in diabetes has not been investigated at the population level.

OBJECTIVE

The objective of this study was to examine the use and potential benefits of chromium supplementation in T2D by examining NHANES data.

METHODS

An individual was defined as having diabetes if he or she had a glycated hemoglobin (HbA1c) value of ≥6.5%, or reported having been diagnosed with diabetes. Data on all consumed dietary supplements from the NHANES database were analyzed, with the OR of having diabetes as the main outcome of interest based on chromium supplement use.

RESULTS

The NHANES for the years 1999-2010 included information on 62,160 individuals. After filtering the database for the required covariates (gender, ethnicity, socioeconomic status, body mass index, diabetes diagnosis, supplement usage, and laboratory HbA1c values), and when restricted to adults, the study cohort included 28,539 people. A total of 58.3% of people reported consuming a dietary supplement in the previous 30 d, 28.8% reported consuming a dietary supplement that contained chromium, and 0.7% consumed supplements that had "chromium" in the title. Compared with nonusers, the odds of having T2D (HbA1c ≥6.5%) were lower in persons who consumed chromium-containing supplements within the previous 30 d than in those who did not (OR: 0.73; 95% CI: 0.62, 0.86; P = 0.001). Supplement use alone (without chromium) did not influence the odds of having T2D (OR: 0.89; 95% CI: 0.77, 1.03; P = 0.11).

CONCLUSIONS

Over one-half the adult US population consumes nutritional supplements, and over one-quarter consumes supplemental chromium. The odds of having T2D were lower in those who, in the previous 30 d, had consumed supplements containing chromium. Given the magnitude of exposure, studies on safety and efficacy are warranted.

New lessons from gastric bypass: Impact of glucose-independent islet function

[Image: see text]

Atazanavir improves cardiometabolic measures but not vascular function in patients with long-standing type 1 diabetes mellitus

AIMS

Vascular disease is the leading cause of morbidity and mortality in type 1 diabetes mellitus (T1DM). We previously demonstrated that patients with T1DM have impaired endothelial function, a forme fruste of atherosclerosis, as a result of increased oxidative stress. Bilirubin has emerged as a potent endogenous antioxidant with higher concentrations associated with lower rates of myocardial infarction and stroke.

METHODS

We tested the hypothesis that increasing endogenous bilirubin using atazanavir would improve cardiometabolic risk factors and vascular function in patients with T1DM to determine whether targeting bilirubin may be a novel therapeutic approach to reduce cardiovascular disease risk in this population. In this single-arm, open-label study, we evaluated blood pressure, lipid profile, and conduit artery function in fifteen subjects (mean age 45 ± 9 years) with T1DM following a 4-day treatment with atazanavir.

RESULTS

As anticipated, atazanavir significantly increased both serum total bilirubin levels (p < 0.0001) and plasma total antioxidant capacity (p < 0.0001). Reductions in total cholesterol (p = 0.04), LDL cholesterol (p = 0.04), and mean arterial pressure (p = 0.04) were also observed following atazanavir treatment. No changes were seen in either flow-mediated endothelium-dependent (p = 0.92) or nitroglycerine-mediated endothelium-independent (p = 0.68) vasodilation, measured by high-resolution B-mode ultrasonography at baseline and post-treatment.

CONCLUSION

Increasing serum bilirubin levels with atazanavir in subjects with T1DM over 4 days favorably reduces LDL and blood pressure but is not associated with improvements in endothelial function of conduit arteries.

Adjustable Gastric Band Surgery or Medical Management in Patients With Type 2 Diabetes: A Randomized Clinical Trial

CONTEXT

Recommendations for surgical, compared with lifestyle and pharmacologically based, approaches for type 2 diabetes (T2D) management remain controversial.

OBJECTIVE

The objective was to compare laparoscopic adjustable gastric band (LAGB) to an intensive medical diabetes and weight management (IMWM) program for T2D.

DESIGN

This was designed as a prospective, randomized clinical trial.

SETTING

The setting was two Harvard Medical School-affiliated academic institutions. INTERVENTIONS AND PARTICIPANTS: A 12-month randomized trial comparing LAGB (n = 23) vs IMWM (n = 22) in persons aged 21-65 years with body mass index of 30-45 kg/m(2), T2D diagnosed more than 1 year earlier, and glycated hemoglobin (HbA(1c)) ≥ 6.5% on antihyperglycemic medication(s).

MAIN OUTCOME MEASURE

The proportion meeting the prespecified primary glycemic endpoint, defined as HbA(1c) < 6.5% and fasting glucose < 7.0 mmol/L at 12 months, on or off medication.

RESULTS

After randomization, five participants did not undergo the surgical intervention. Of the 40 initiating intervention (22 males/18 females; age, 51 ± 10 y; body mass index, 36.5 ± 3.7 kg/m(2); diabetes duration, 9 ± 5 y; HbA(1c), 8.2 ± 1.2%; 40% on insulin), the proportion meeting the primary glycemic endpoint was achieved in 33% of the LAGB patients and 23% of the IMWM patients (P = .457). HbA(1c) reduction was similar between groups at both 3 and 12 months (-1.2 ± 0.3 vs -1.0 ± 0.3%; P = .496). Weight loss was similar at 3 months but greater 12 months after LAGB (-13.5 ± 1.7 vs -8.5 ± 1.6 kg; P = .027). Systolic blood pressure reduction was greater after IMWM than LAGB, whereas changes in diastolic blood pressure, lipids, fitness, and cardiovascular risk scores were similar between groups. Patient-reported health status, assessed using the Short Form-36, Impact of Weight on Quality of Life, and Problem Areas in Diabetes, all improved similarly between groups.

CONCLUSIONS

LAGB and a multidisciplinary IMWM program have similar 1-year benefits on diabetes control, cardiometabolic risk, and patient satisfaction, which should be considered in the context of other factors, such as personal preference, when selecting treatment options with obese T2D patients. Longer duration studies are important to understand emergent differences.

Diabetes primes neutrophils to undergo NETosis, which impairs wound healing

Wound healing is impaired in diabetes, resulting in significant morbidity and mortality. Neutrophils are the main leukocytes involved in the early phase of healing. As part of their anti-microbial defense, neutrophils form extracellular traps (NETs) by releasing decondensed chromatin lined with cytotoxic proteins. NETs, however, can also induce tissue damage. Here we show that neutrophils isolated from type 1 and type 2 diabetic humans and mice were primed to produce NETs (a process termed NETosis). Expression of peptidylarginine deiminase 4 (PAD4, encoded by Padi4 in mice), an enzyme important in chromatin decondensation, was elevated in neutrophils from individuals with diabetes. When subjected to excisional skin wounds, wild-type (WT) mice produced large quantities of NETs in wounds, but this was not observed in Padi4(-/-) mice. In diabetic mice, higher levels of citrullinated histone H3 (H3Cit, a NET marker) were found in their wounds than in normoglycemic mice and healing was delayed. Wound healing was accelerated in Padi4(-/-) mice as compared to WT mice, and it was not compromised by diabetes. DNase 1, which disrupts NETs, accelerated wound healing in diabetic and normoglycemic WT mice. Thus, NETs impair wound healing, particularly in diabetes, in which neutrophils are more susceptible to NETosis. Inhibiting NETosis or cleaving NETs may improve wound healing and reduce NET-driven chronic inflammation in diabetes.

Differential Gene Expression in Diabetic Nephropathy in Individuals With Type 1 Diabetes

CONTEXT

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease (ESRD) in the United States.

OBJECTIVE

The aim of this study was to determine whether there were skin fibroblast gene expression differences between subjects with type 1 diabetes (T1D) with or without DN.

SETTING

This was a cross-sectional study conducted in the University of Minnesota.

PATIENTS

Study volunteers were 100 former participants of Genetics of Kidneys in Diabetes: 40 were diabetic nephropathy (DN) Controls, normoalbuminuric after ≥ 15 years of T1D; and 60 were DN Cases, 25 with proteinuria and 35 with ESRD.

INTERVENTION(S)

Skin fibroblasts were grown in high glucose (HG) for five passages (approximately 6 weeks).

MAIN OUTCOME MEASURE(S)

SF gene expression was assessed by transcriptome sequencing using the Illumina HiSeq 2000 platform. Pathway analyses tested directionally consistent group differences within the Kyoto Encyclopedia of Genes and Genomes pathways.

RESULTS

Eight pathways, all related to cell cycle and repair, were up-regulated in the DN Controls vs the DN Cases. These pathways markedly overlapped with the pathways up-regulated by HG in T1D monozygotic twins (MZT), but not in their non-T1D MZT. DN Cases showed statistical trends toward up-regulation of these pathways vs non-T1D MZT, but much less so than the DN Controls.

CONCLUSIONS

Together, these data suggest that SF from T1D patients undergo epigenetic modifications resulting in increased expression of genes in healing and repair pathways. These responses, much more robust in patients protected from DN, suggest that epigenetic factors are important in DN risk.

Insulin response to oral stimuli and glucose effectiveness increased in neuroglycopenia following gastric bypass

OBJECTIVE

Hyperinsulinemic hypoglycemia with neuroglycopenia is a rare complication following Roux-en-Y gastric bypass (RYGB) surgery for weight management. Insulin secretion and action in response to oral and intravenous stimuli in persons with and without neuroglycopenia following RYGB are evaluated in this study.

METHODS

Cross-sectional cohort studies were performed at a single academic institution to assess insulin secretion and action during oral mixed meal tolerance test and intravenous glucose tolerance test (IVGTT).

RESULTS

Insulin secretion was increased more following oral mixed meal than intravenous glucose in individuals with neuroglycopenia compared to the asymptomatic group. Reduced insulin clearance did not contribute to higher insulinemia. Glucose effectiveness at zero insulin, estimated during the IVGTT, was also higher in those with neuroglycopenia. Insulin sensitivity did not differ between groups.

CONCLUSIONS

Increased beta-cell response to oral stimuli and insulin-independent glucose disposal may both contribute to severe hypoglycemia after RYGB.

Effect of paricalcitol on endothelial function and inflammation in type 2 diabetes and chronic kidney disease

AIMS

Patients with type 2 diabetes (T2DM) and chronic kidney disease (CKD) have impaired endothelial function. Vitamin D and its analogs may play a role in regulation of endothelial function and inflammation. We studied effects of paricalcitol compared to placebo on endothelial function and markers of inflammation and oxidative stress in patients with T2DM and CKD.

METHODS

A double blind, randomized, placebo-controlled trial was conducted in 60 patients with T2DM and stage 3 or 4 CKD. Paricalcitol 1 mcg or placebo was administered orally once daily for three months. Brachial artery flow mediated dilatation (FMD), nitroglycerine mediated dilation (NMD), and plasma concentrations of inflammatory cytokines, tumor necrosis factor -α and interleukin-6, highly-sensitive C-reactive protein; endothelial surface proteins, intercellular adhesion molecule -1 and monocyte chemo attractant protein-1, and plasma glucose, insulin, free fatty acids, and urinary isoprostane were measured at baseline and end of three months.

RESULTS

27 patients in the paricalcitol group and 28 patients in the control group completed the study, though analysis of FMD at both time points was possible in 23 patients in each group. There was no significant difference in the change in FMD, NMD or the biomarkers examined after paricalcitol or placebo treatment.

CONCLUSIONS

Treatment with paricalcitol at this dose and duration did not affect brachial artery FMD or biomarkers of inflammation and oxidative stress. The lack of significance may be due to the fact that the study patients had advanced CKD and that effects of paricalcitol are not additive to the effects of glycemic, lipid and anti-hypertensive therapies.

Dipeptidyl peptidase-4 inhibitors do not increase the risk of cardiovascular events in type 2 diabetes: a cohort study

AIMS

Two recent randomized controlled trials of type 2 diabetes mellitus (T2DM) patients with history of, or at high risk of, cardiovascular disease (CVD) showed no risk of ischemic cardiovascular events associated with dipeptidyl peptidase-4 inhibitors (DPP4i), but an increased risk of heart failure (HF) with saxagliptin. We evaluated the risk of CVD including myocardial infarction (MI), stroke, coronary revascularization, and HF associated with DPP4i in T2DM patients with and without baseline CVD as used in the community.

METHODS

Using US commercial insurance claims data (2005-2012), we conducted a cohort study that included initiators of DPP4i and non-DPP4i treatments. Composite CVD endpoints including MI, stroke, coronary revascularization, and HF were defined with a hospital discharge diagnosis or procedure code. Cox proportional hazards models compared the risk of composite and individual CVD endpoints in propensity score (PS)-matched initiators of DPP4 versus non-DPP4i.

RESULTS

We included 79,538 (18 % with baseline CVD) persons in PS-matched pairs of DPP4i and non-DPP4i initiators. The incidence rate per 1,000 person-years for composite CVD was 30.30 (95 % CI 28.24-32.51) in DPP4i and 34.76 (95 % CI 32.34-37.36) in non-DPP4i. The PS-matched hazard ratio (HR) for composite CVD was 0.87 (95 % CI 0.79-0.96) in DPP4i versus non-DPP4i. The PS-matched HR for HF was 0.81 (95 % CI 0.70-0.94) in DPP4i versus non-DPP4i. Among patients with baseline CVD, there was no increased risk of CVD or HF associated with DPP4i use.

CONCLUSIONS

Among T2DM patients, initiating DPP4i was not associated with a greater risk of CVD or HF compared to non-DPP4i initiators.

Visceral adiposity and the risk of metabolic syndrome across body mass index: the MESA Study

OBJECTIVES

This study sought to evaluate differential effects of visceral fat (VF) and subcutaneous fat and their effects on metabolic syndrome (MetS) risk across body mass index (BMI) categories.

BACKGROUND

The regional distribution of adipose tissue is an emerging risk factor for cardiometabolic disease, although serial changes in fat distribution have not been extensively investigated. VF and its alterations over time may be a better marker for risk than BMI in normal weight and overweight or obese individuals.

METHODS

We studied 1,511 individuals in the MESA (Multi-Ethnic Study of Atherosclerosis) with adiposity assessment by computed tomography (CT). A total of 253 participants without MetS at initial scan underwent repeat CT (median interval 3.3 years). We used discrete Cox regression with net reclassification to investigate whether baseline and changes in VF area are associated with MetS.

RESULTS

Higher VF was associated with cardiometabolic risk and coronary artery calcification, regardless of BMI. After adjustment, VF was more strongly associated with incident MetS than subcutaneous fat regardless of weight, with a 28% greater MetS hazard per 100 cm(2)/m VF area and significant net reclassification (net reclassification index: 0.44, 95% confidence interval [CI]: 0.29 to 0.60) over clinical risk. In individuals with serial imaging, initial VF (hazard ratio: 1.24 per 100 cm(2)/m, 95% CI: 1.08 to 1.44 per 100 cm(2)/m, p = 0.003) and change in VF (hazard ratio: 1.05 per 5% change, 95% CI: 1.01 to 1.08 per 5% change, p = 0.02) were associated with MetS after adjustment. Changes in subcutaneous fat were not associated with incident MetS after adjustment for clinical risk and VF area.

CONCLUSIONS

VF is modestly associated with BMI. However, across BMI, a single measure of and longitudinal change in VF predict MetS, even accounting for weight changes. Visceral adiposity is essential to assessing cardiometabolic risk, regardless of age, race, or BMI, and may serve as a marker and target of therapy in cardiometabolic disease.

Roux-en-Y gastric bypass surgery or lifestyle with intensive medical management in patients with type 2 diabetes: feasibility and 1-year results of a randomized clinical trial

IMPORTANCE

Emerging data support bariatric surgery as a therapeutic strategy for management of type 2 diabetes mellitus.

OBJECTIVE

To test the feasibility of methods to conduct a larger multisite trial to determine the long-term effect of Roux-en-Y gastric bypass (RYGB) surgery compared with an intensive diabetes medical and weight management (Weight Achievement and Intensive Treatment [Why WAIT]) program for type 2 diabetes.

DESIGN, SETTING, AND PARTICIPANTS

A 1-year pragmatic randomized clinical trial was conducted in an academic medical institution. Participants included persons aged 21 to 65 years with type 2 diabetes diagnosed more than 1 year before the study; their body mass index was 30 to 42 (calculated as weight in kilograms divided by height in meters squared) and hemoglobin A1c (HbA1c) was greater than or equal to 6.5%. All participants were receiving antihyperglycemic medications.

INTERVENTIONS

RYGB (n = 19) or Why WAIT (n = 19) including 12 weekly multidisciplinary group lifestyle, medical, and educational sessions with monthly follow-up thereafter.

MAIN OUTCOMES AND MEASURES

Proportion of patients with fasting plasma glucose levels less than 126 mg/dL and HbA1c less than 6.5%, measures of cardiometabolic health, and patient-reported outcomes.

RESULTS

At 1 year, the proportion of patients achieving HbA1c below 6.5% and fasting glucose below 126 mg/dL was higher following RYGB than Why WAIT (58% vs 16%, respectively; P = .03). Other outcomes, including HbA1c, weight, waist circumference, fat mass, lean mass, blood pressure, and triglyceride levels, decreased and high-density lipoprotein cholesterol increased more after RYGB compared with Why WAIT. Improvement in cardiovascular risk scores was greater in the surgical group. At baseline the participants exhibited moderately low self-reported quality-of-life scores reflected by Short Form-36 total, physical health, and mental health, as well as high Impact of Weight on Quality of Life-Lite and Problem Areas in Diabetes health status scores. At 1 year, improvements in Short Form-36 physical and mental health scores and Problem Areas in Diabetes scores did not differ significantly between groups. The Impact of Weight on Quality of Life-Lite score improved more with RYGB and correlated with greater weight loss compared with Why WAIT.

CONCLUSIONS AND RELEVANCE

In obese patients with type 2 diabetes, RYGB produces greater weight loss and sustained improvements in HbA1c and cardiometabolic risk factors compared with medical management, with emergent differences over 1 year. Both treatments improve general quality-of-life measures, but RYGB provides greater improvement in the effect of weight on quality of life. These differences may help inform therapeutic decisions for diabetes and weight loss strategies in obese patients with type 2 diabetes until larger randomized trials are performed.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01073020.

Dipeptidyl peptidase-4 inhibitors in type 2 diabetes may reduce the risk of autoimmune diseases: a population-based cohort study

OBJECTIVE

Dipeptidyl peptidase-4 (DPP4), also known as CD26, is a transmembrane glycoprotein that has a costimulatory function in the immune response. DPP4 inhibitors (DPP4i) are oral glucose-lowering drugs for type 2 diabetes mellitus (T2DM). This study evaluated the risk of incident rheumatoid arthritis (RA) and other autoimmune diseases (AD) such as systemic lupus erythematosus, psoriasis, multiple sclerosis and inflammatory bowel disease, associated with DPP4i in patients with T2DM.

METHODS

Using US insurance claims data (2005-2012), we conducted a population-based cohort study that included initiators of combination therapy with DPP4i (DPP4i plus metformin) and non-DPP4i (non-DPP4i plus metformin). RA and other AD were identified with ≥2 diagnoses and ≥1 dispensing for AD-specific immunomodulating drugs or steroids. Composite AD includes RA or other AD. Propensity score (PS)-stratified Cox proportional hazards models compared the risk of AD in DPP4i initiators versus non-DPP4i, controlling for potential confounders.

RESULTS

After asymmetric trimming on the PS, 73 928 patients with T2DM starting DPP4i combination therapy and 163 062 starting non-DPP4i combination therapy were selected. Risks of incident RA and composite AD were lower in the DPP4i group versus non-DPP4i with the PS-stratified HR of 0.66 (95% CI 0.44 to 0.99) for RA, 0.73 (0.51 to 1.03) for other AD and 0.68 (95% CI 0.52 to 0.89) for composite AD.

CONCLUSIONS

In this large cohort of diabetic patients, those initiating DPP4i combination therapy appear to have a decreased risk of incident AD including RA compared with those initiating non-DPP4i combination therapy. These results may suggest possible pharmacological pathways for prevention or treatment of AD.

Coordination chemistry may explain pharmacokinetics and clinical response of vanadyl sulfate in type 2 diabetic patients

Vanadium, abbreviated V, is an early transition metal that readily forms coordination complexes with a variety of biological products such as proteins, metabolites, membranes and other structures. The formation of coordination complexes stabilizes metal ions, which in turn impacts the biodistribution of the metal. To understand the biodistribution of V, V in oxidation state iv in the form of vanadyl sulfate (25, 50, 100 mg V daily) was given orally for 6 weeks to 16 persons with type 2 diabetes. Elemental V was determined using Graphite Furnas Atomic Absorption Spectrometry against known concentrations of V in serum, blood or urine. Peak serum V levels were 15.4 ± 6.5, 81.7 ± 40 and 319 ± 268 ng ml(-1) respectively, and mean peak serum V was positively correlated with dose administered (r = 0.992, p = 0.079), although large inter-individual variability was found. Total serum V concentration distribution fit a one compartment open model with a first order rate constant for excretion with mean half times of 4.7 ± 1.6 days and 4.6 ± 2.5 days for the 50 and 100 mg V dose groups respectively. At steady state, 24 hour urinary V output was 0.18 ± 0.24 and 0.97 ± 0.84 mg in the 50 and 100 mg V groups respectively, consistent with absorption of 1 percent or less of the administered dose. Peak V in blood and serum were positively correlated (r = 0.971, p < 0.0005). The serum to blood V ratio for the patients receiving 100 mg V was 1.7 ± 0.45. Regression analysis showed that glycohemoglobin was a negative predictor of the natural log(ln) peak serum V (R(2) = 0.40, p = 0.009) and a positive predictor of the euglycemic-hyperinsulinemic clamp results at high insulin values (R(2) = 0.39, p = 0.010). Insulin sensitivity measured by euglycemic-hyperinsulinemic clamp was not significantly correlated with ln peak serum V. Globulin and glycohemoglobin levels taken together were negative predictors of fasting blood glucose (R(2) = 0.49, p = 0.013). Although V accumulation in serum was dose-dependent, no correlation between total serum V concentration and the insulin-like response was found in this first attempt to correlate anti-diabetic activity with total serum V. This study suggests that V pools other than total serum V are likely related to the insulin-like effect of this metal. These results, obtained in diabetic patients, document the need for consideration of the coordination chemistry of metabolites and proteins with vanadium in anti-diabetic vanadium complexes.

The impact of salsalate treatment on serum levels of advanced glycation end products in type 2 diabetes

OBJECTIVE Salsalate is a nonacetylated salicylate that lowers glucose levels in people with type 2 diabetes (T2D). Here we examined whether salsalate also lowered serum-protein-bound levels of early and advanced glycation end products (AGEs) that have been implicated in diabetic vascular complications. RESEARCH DESIGN AND METHODS Participants were from the Targeting Inflammation Using Salsalate for Type 2 Diabetes (TINSAL-T2D) study, which examined the impact of salsalate treatment on hemoglobin A1c (HbA1c) and a wide variety of other parameters. One hundred eighteen participants received salsalate, 3.5 g/day for 48 weeks, and 109 received placebo. Early glycation product levels (HbA1c and fructoselysine [measured as furosine]) and AGE levels (glyoxal and methylglyoxal hydroimidazolones [G-(1)H, MG-(1)H], carboxymethyllysine [CML], carboxyethyllysine [CEL], pentosidine) were measured in patient serum samples. RESULTS Forty-eight weeks of salsalate treatment lowered levels of HbA1c and serum furosine (P < 0.001) and CML compared with placebo. The AGEs CEL and G-(1)H and MG-(1)H levels were unchanged, whereas pentosidine levels increased more than twofold (P < 0.001). Among salsalate users, increases in adiponectin levels were associated with lower HbA1c levels during follow-up (P < 0.001). Changes in renal and inflammation factor levels were not associated with changes in levels of early or late glycation factors. Pentosidine level changes were unrelated to changes in levels of renal function, inflammation, or cytokines. CONCLUSIONS Salsalate therapy was associated with a reduction in early but not late glycation end products. There was a paradoxical increase in serum pentosidine levels suggestive of an increase in oxidative stress or decreased clearance of pentosidine precursor.

Fasting serum taurine-conjugated bile acids are elevated in type 2 diabetes and do not change with intensification of insulin

CONTEXT

Bile acids (BAs) are newly recognized signaling molecules in glucose and energy homeostasis. Differences in BA profiles with type 2 diabetes mellitus (T2D) remain incompletely understood.

OBJECTIVE

The objective of the study was to assess serum BA composition in impaired glucose-tolerant, T2D, and normal glucose-tolerant persons and to monitor the effects of improving glycemia on serum BA composition in T2D patients.

DESIGN AND SETTING

This was a cross-sectional cohort study in a general population (cohort 1) and nonrandomized intervention (cohort 2).

PATIENTS AND INTERVENTIONS

Ninety-nine volunteers underwent oral glucose tolerance testing, and 12 persons with T2D and hyperglycemia underwent 8 weeks of intensification of treatment.

MAIN OUTCOME MEASURES

Serum free BA and respective taurine and glycine conjugates were measured by HPLC tandem mass spectrometry.

RESULTS

Oral glucose tolerance testing identified 62 normal-, 25 impaired glucose-tolerant, and 12 T2D persons. Concentrations of total taurine-conjugated BA were higher in T2D and intermediate in impaired- compared with normal glucose-tolerant persons (P = .009). Univariate regression revealed a positive association between total taurine-BA and fasting glucose (R = 0.37, P < .001), postload glucose (R = 0.31, P < .002), hemoglobin A1c (R = 0.26, P < .001), fasting insulin (R = 0.21, P = .03), and homeostatic model assessment-estimated insulin resistance (R = 0.26, P = .01) and an inverse association with oral disposition index (R = -0.36, P < .001). Insulin-mediated glycemic improvement in T2D patients did not change fasting serum total BA or BA composition.

CONCLUSION

Fasting taurine-conjugated BA concentrations are higher in T2D and intermediate in impaired compared with normal glucose-tolerant persons and are associated with fasting and postload glucose. Serum BAs are not altered in T2D in response to improved glycemia. Further study may elucidate whether this pattern of taurine-BA conjugation can be targeted to provide novel therapeutic approaches to treat T2D.