M. Nieuwdorp

Effect of sulodexide on endothelial glycocalyx and vascular permeability in patients with type 2 diabetes mellitus

Aims/hypothesisEndothelial glycocalyx perturbation contributes to increased vascular permeability. In the present study we set out to evaluate whether: (1) glycocalyx is perturbed in individuals with type 2 diabetes mellitus, and (2) oral glycocalyx precursor treatment improves glycocalyx properties.MethodsMale participants with type 2 diabetes (nu2009=u200910) and controls (nu2009=u200910) were evaluated before and after 2xa0months of sulodexide administration (200xa0mg/day). The glycocalyx dimension was estimated in two different vascular beds using sidestream dark field imaging and combined fluorescein/indocyanine green angiography for sublingual and retinal vessels, respectively. Transcapillary escape rate of albumin (TERalb) and hyaluronan catabolism were assessed as measures of vascular permeability.ResultsBoth sublingual dimensions (0.64 [0.57–0.75] μm vs 0.78 [0.71–0.85] μm, pu2009<u20090.05, medians [interquartile range]) and retinal glycocalyx dimensions (5.38 [4.88–6.59] μm vs 8.89 [4.74–11.84] μm, pu2009<u20090.05) were reduced in the type 2 diabetes group compared with the controls whereas TERalb was increased (5.6u2009±u20092.3% vs 3.7u2009±u20091.7% in the controls, pu2009<u20090.05). In line with these findings, markers of hyaluronan catabolism were increased with diabetes (hyaluronan 137u2009±u200929 vs 81u2009±u20098xa0ng/ml and hyaluronidase 78u2009±u20094 vs 67u2009±u20092xa0U/ml, both pu2009<u20090.05). Sulodexide increased both the sublingual and retinal glycocalyx dimensions in participants with diabetes (to 0.93 [0.83–0.99] μm and to 5.88 [5.33–6.26] μm, respectively, pu2009<u20090.05). In line, a trend towards TERalb normalisation (to 4.0u2009±u20092.3%) and decreases in plasma hyaluronidase (to 72u2009±u20092xa0U/ml, pu2009<u20090.05) were observed in the diabetes group.Conclusion/interpretationType 2 diabetes is associated with glycocalyx perturbation and increased vascular permeability, which are partially restored following sulodexide administration. Further studies are warranted to determine whether long-term treatment with sulodexide has a beneficial effect on cardiovascular risk.Trial registrationwww.trialregister.nl NTR780/http://isrctn.org ISRCTN82695186FundingAn unrestricted Novartis Foundation for Cardiovascular Excellence grant (2006) to M. Nieuwdorp/E. S. G. Stroes, Dutch Heart Foundation (grant number 2005T037)

Consensus report: faecal microbiota transfer – clinical applications and procedures

Faecal microbiota transplantation or transfer (FMT) aims at replacing or reinforcing the gut microbiota of a patient with the microbiota from a healthy donor. Not many controlled or randomised studies have been published evaluating the use of FMT for other diseases than Clostridium difficile infection, making it difficult for clinicians to decide on a suitable indication.

High daily insulin exposure in patients with type 2 diabetes is associated with increased risk of cardiovascular events.

AIMSnIntensive glucose control, often involving insulin treatment, failed to improve cardiovascular outcomes in several clinical trials. Observational studies reported an association between insulin use and cardiovascular disease (CVD) risk. It has therefore been suggested that insulin adversely affects CVD risk. To investigate the feasibility of this hypothesis, we studied the association between insulin dose and CVD risk in type 2 diabetes.nnnMETHODSnA case-control study was conducted of new users of oral antidiabetics who were prescribed insulin, using the Dutch Pharmo database. Cases were hospitalized for a cardiovascular event (CVE) and matched 1:2 to patients who were not hospitalized for a CVE, by sex, age, duration of diabetes and type of oral antidiabetic. Patients were divided into tertiles according to mean daily insulin dose. Conditional logistic regression analyses were used to explore the association between insulin exposure and CVE risk.nnnRESULTSnWe included 836 patients (517 (62%) male, mean age 66 years). After adjusting for available potential confounders, including HbA1c and triglycerides, insulin exposure was positively related to CVE risk (odds ratios for high (≥53.0 U/day) and intermediate (24.3-52.9 U/day) vs. low exposure (≤24.2 U/day): 3.00 [95% confidence interval (CI) 1.70 to 5.28] and 2.03 [95% CI 1.17 to 3.52].nnnCONCLUSIONnOur findings are in line with the suggestion that high-dose insulin therapy adversely affects CVD risk, but need to be interpreted with caution due to the observational nature of the study. The role of particularly high-dose insulin in the progression of CVD warrants further investigation.

Methods for quantifying adipose tissue insulin resistance in overweight/obese humans

Background/Objectives:Insulin resistance of adipose tissue is an important feature of obesity-related metabolic disease. However, assessment of lipolysis in humans requires labor-intensive and expensive methods, and there is limited validation of simplified measurement methods. We aimed to validate simplified methods for the quantification of adipose tissue insulin resistance against the assessment of insulin sensitivity of lipolysis suppression during hyperinsulinemic–euglycemic clamp studies.Subjects/Methods:We assessed the insulin-mediated suppression of lipolysis by tracer-dilution of [1,1,2,3,3-2H5]glycerol during hyperinsulinemic–euglycemic clamp studies in 125 overweight or obese adults (85 men, 40 women; age 50±11 years; body mass index 38±7u2009kgu2009m−2). Seven indices of adipose tissue insulin resistance were validated against the reference measurement method.Results:Low-dose insulin infusion resulted in suppression of the glycerol rate of appearance ranging from 4% (most resistant) to 85% (most sensitive), indicating a good range of adipose tissue insulin sensitivity in the study population. The reference method correlated with (1) insulin-mediated suppression of plasma glycerol concentrations (r=0.960, P<0.001), (2) suppression of plasma non-esterified fatty acid (NEFA) concentrations (r=0.899, P<0.001), (3) the Adipose tissue Insulin Resistance (Adipo-IR) index (fasting plasma insulin–NEFA product; r=−0.526, P<0.001), (4) the fasting plasma insulin–glycerol product (r=−0.467, P<0.001), (5) the Adipose Tissue Insulin Resistance Index (fasting plasma insulin–basal lipolysis product; r=0.460, P<0.001), (6) the Quantitative Insulin Sensitivity Check Index (QUICKI)-NEFA index (r=0.621, P<0.001), and (7) the QUICKI-glycerol index (r=0.671, P<0.001). Bland–Altman plots showed no systematic errors for the suppression indices but proportional errors for all fasting indices. Receiver-operator characteristic curves confirmed that all indices were able to detect adipose tissue insulin resistance (area under the curve ⩾0.801, P<0.001).Conclusions:Adipose tissue insulin sensitivity (that is, the antilipolytic action of insulin) can be reliably quantified in overweight and obese humans by simplified index methods. The sensitivity and specificity of the Adipo-IR index and the fasting plasma insulin–glycerol product, combined with their simplicity and acceptable agreement, suggest that these may be most useful in clinical practice.

Loss of function in heparan sulfate elongation genes EXT1 and EXT 2 results in improved nitric oxide bioavailability and endothelial function.

Background Heparanase is the major enzyme involved in degradation of endothelial heparan sulfates, which is associated with impaired endothelial nitric oxide synthesis. However, the effect of heparan sulfate chain length in relation to endothelial function and nitric oxide availability has never been investigated. We studied the effect of heterozygous mutations in heparan sulfate elongation genes EXT1 and EXT2 on endothelial function in vitro as well as in vivo. Methods and Result Flow‐mediated dilation, a marker of nitric oxide bioavailability, was studied in Ext1+/− and Ext2+/− mice versus controls (n=7 per group), as well as in human subjects with heterozygous loss of function mutations in EXT1 and EXT2 (n=13 hereditary multiple exostoses and n=13 controls). Endothelial function was measured in microvascular endothelial cells under laminar flow with or without siRNA targeting EXT1 or EXT2. Endothelial glycocalyx and maximal arteriolar dilatation were significantly altered in Ext1+/− and Ext2+/− mice compared to wild‐type littermates (glycocalyx: wild‐type 0.67±0.1 μm, Ext1+/− 0.28±0.1 μm and Ext2+/− 0.25±0.1 μm, P<0.01, maximal arteriolar dilation during reperfusion: wild‐type 11.3±1.0%), Ext1+/− 15.2±1.4% and Ext2+/− 13.8±1.6% P<0.05). In humans, brachial artery flow‐mediated dilation was significantly increased in hereditary multiple exostoses patients (hereditary multiple exostoses 8.1±0.8% versus control 5.6±0.7%, P<0.05). In line, silencing of microvascular endothelial cell EXT1 and EXT2 under flow led to significant upregulation of endothelial nitric oxide synthesis and phospho‐endothelial nitric oxide synthesis protein expression. Conclusions Our data implicate that heparan sulfate elongation genes EXT1 and EXT2 are involved in maintaining endothelial homeostasis, presumably via increased nitric oxide bioavailability.

PS4 - 5. Administration of Eubacterium hallii improves insulin sensitivity and degree of liversteatosis in male db/db mice

The development of obesity and type 2 diabetes is associated with substantial changes in the composition of (small) intestinal microbiota. Using lean donor fecal transplantations in subjects with metabolic syndrome, we showed that improvement in insulin sensitivity associated with increased levels in small intestinal mucosal biopsies of Eubacterium hallii (an anaerobic butyrate producing bacteria belonging to Clostridium cluster XIVa).

PS3 - 15. Genetic Variation at the SULF2 Locus Affects Hepatic Postprandial Remnant Clearance in Patients with Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is characterized by elevated plasma levels of atherogenic triglyceride-rich lipoproteins (TRL). Recent animal data revealed that heparansulfate proteoglycans (HSPGs) contribute to hepatic clearance of TRL. Hepatic glucosamine-6-O-endosulfatase-2 (SULF2), an enzyme involved in HSPG remodeling, is strongly associated with triglyceride (TG) levels in db/db mice.

PS14 - 68. Differential effects of antibiotics on bile acid metabolism, intestinal microbiota composition and insulin resistance in obese humans; a randomised controlled trial

Recent data in animal models reveal that obesity is associated with substantial changes in composition and metabolic function of gut microbiota.

PS14 - 70. Intestinal microbiota translocation is associated with inflamed visceral adipose tissue

Inflammation of visceral fat is a key regulator in the development of insulin resistance and subsequent type 2 diabetes, yet the pathophysiological trigger for this chronic inflammation remains poorly understood.