Synergies of THESEUS with the large facilities of the 2030s and guest observer opportunities

The proposed THESEUS mission will vastly expand the capabilities to monitor the high-energy sky. It will specifically exploit large samples of gamma-ray bursts to probe the early universe back to the first generation of stars, and to advance multi-messenger astrophysics by detecting and localizing the counterparts of gravitational waves and cosmic neutrino sources. The combination and coordination of these activities with multi-wavelength, multi-messenger facilities expected to be operating in the 2030s will open new avenues of exploration in many areas of astrophysics, cosmology and fundamental physics, thus adding considerable strength to the overall scientific impact of THESEUS and these facilities. We discuss here a number of these powerful synergies and guest observer opportunities.

Compact radio emission indicates a structured jet was produced by a binary neutron star merger

The binary neutron star merger event GW170817 was detected through both electromagnetic radiation and gravitational waves. Its afterglow emission may have been produced by either a narrow relativistic jet or an isotropic outflow. High-spatial-resolution measurements of the source size and displacement can discriminate between these scenarios. We present very-long-baseline interferometry observations, performed 207.4 days after the merger by using a global network of 32 radio telescopes. The apparent source size is constrained to be smaller than 2.5 milli-arc seconds at the 90% confidence level. This excludes the isotropic outflow scenario, which would have produced a larger apparent size, indicating that GW170817 produced a structured relativistic jet. Our rate calculations show that at least 10% of neutron star mergers produce such a jet.

Charcot Neuroarthropathy: From the Laboratory to the Bedside

BACKGROUND

The diabetic Charcot foot syndrome is a serious and potentially limbthreatening lower-extremity complication of diabetes.

INTRODUCTION

The present review provides a concise account of the advances made over the last twentyfive years in understanding the pathogenesis and management of Charcot neuroarthropathy (CN).

METHODS

In this study, the widely known pathogenetic mechanisms underpinning CN are brought into focus, particularly the role of RANKL/RANK/OPG system and advanced glycation end production in the pathogenesis of CN. Furthermore, other potential triggering factors, namely nitric oxide, endothelial dysfunction, macro calcifications and body weight that influence CN have also been discussed.

RESULTS

The wide range of diagnostic tools available to clinicians for accurate staging of this pathology has been examined, particularly radiological and nuclear medicine imaging. Additionally, the difficult differential diagnosis between osteomyelitis and CN is also elucidated.

CONCLUSION

The review concludes with the comprehensive summary of the major promising therapeutic strategies, including conservative treatment involving orthopedic devices, pharmacological approach, and the most common surgical techniques currently employed in the diagnosis and treatment of this acute disease.

Platelet indices and glucose control in type 1 and type 2 diabetes mellitus: A case-control study

BACKGROUND AND AIMS

The relationship between platelet indices and glucose control may differ in type 1 (T1DM) and type 2 (T2DM) diabetes. We aimed to investigate differences in mean platelet volume (MPV), platelet count, and platelet mass between patients with T1DM, T2DM, and healthy controls and to explore associations between these platelet indices and glucose control.

METHODS AND RESULTS

A total of 691 T1DM and 459 T2DM patients and 943 control subjects (blood donors) were included. HbA1c was measured in all subjects with diabetes and 36 T1DM patients further underwent 24 h-continuous glucose monitoring to estimate short-term glucose control (glucose mean and standard deviation). Adjusting for age and sex, platelet count was higher and MPV lower in both T1DM and T2DM patients vs control subjects, while platelet mass (MPV × platelet count) resulted higher only in T2DM. Upon further adjustment for HbA1c, differences in platelet count and mass were respectively 19.5 × 10⁹/L (95%CI: 9.8-29.3; p < 0.001) and 101 fL/nL (12-191; p = 0.027) comparing T2DM vs T1DM patients. MPV and platelet count were significantly and differently related in T2DM patients vs both T1DM and control subjects; this difference was maintained also accounting for HbA1c, age, and sex. Platelet mass and the volume-count relationship were significantly related to HbA1c only in T1DM patients. No associations were found between platelet indices and short-term glucose control.

CONCLUSION

By accounting for confounders and glucose control, our data evidenced higher platelet mass and different volume-count kinetics in subjects with T2DM vs T1DM. Long-term glucose control seemed to influence platelet mass and the volume-count relationship only in T1DM subjects. These findings suggest different mechanisms behind platelet formation in T1DM and T2DM patients with long-term glycaemic control being more relevant in T1DM than T2DM.

Autoantibodies to post-translationally modified type I and II collagen in Charcot neuroarthropathy in subjects with type 2 diabetes mellitus

AIMS

Charcot neuroarthropathy (CN) is a disabling complication, culminating in bone destruction and involving joints and articular cartilage with high inflammatory environment. Its real pathogenesis is as yet unknown. In autoinflammatory diseases, such as rheumatoid arthritis, characterized by inflammation and joint involvement, autoantibodies against oxidative post-translationally modified (oxPTM) collagen type I (CI) and type II (CII) were detected. Therefore, the aim of our study was to assess the potential involvement of autoimmunity in charcot neuroarthropathy, investigating the presence of autoantibodies oxPTM-CI and oxPTM-CII, in participants with charcot neuroarthropathy.

METHODS

In this case-control study, we enrolled 124 participants with type 2 diabetes mellitus (47 with charcot neuroarthropathy, 37 with diabetic peripheral neuropathy without charcot neuroarthropathy, and 40 with uncomplicated diabetes), and 32 healthy controls. The CI and CII were modified with ribose and other oxidant species, and the modifications were evaluated with sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Binding of sera from the participants was analyzed with enzyme-linked immunosorbent assay.

RESULTS

Age, body mass index, waist and hip circumferences, and lipid profile were similar across the 4 groups, as well as glycated hemoglobin and duration of diabetes among people with diabetes. An increased binding to both native and all oxidation-modified forms of CII was found in participants with CN and diabetic neuropathy. Conversely, for CI, an aspecific increased reactivity was noted.

CONCLUSIONS

Our results detected the presence of autoantibodies against oxidative post-translational modified collagen, particularly type 2 collagen, in participants with charcot neuroarthropathy and diabetic neuropathy, suggesting the possible involvement of autoimmunity. Further studies are required to understand the role of autoimmunity in the pathogenesis of charcot neuroarthropathy.

Design Strategies for Redox Active Metalloenzymes: Applications in Hydrogen Production

The last decades have seen an increased interest in finding alternative means to produce renewable fuels in order to satisfy the growing energy demands and to minimize environmental impact. Nature can serve as an inspiration for development of these methodologies, as enzymes are able to carry out a wide variety of redox processes at high efficiency, employing a wide array of earth-abundant transition metals to do so. While it is well recognized that the protein environment plays an important role in tuning the properties of the different metal centers, the structure/function relationships between amino acids and catalytic centers are not well resolved. One specific approach to study the role of proteins in both electron and proton transfer is the biomimetic design of redox active peptides, binding organometallic clusters in well-understood protein environments. Here we discuss different strategies for the design of peptides incorporating redox active FeS clusters, [FeFe]-hydrogenase organometallic mimics, and porphyrin centers into different peptide and protein environments in order to understand natural redox enzymes.

Possible Radio Interference Between Video Capsule Endoscopy and Second-Generation OmniPod Patch Pump

Video capsule endoscopy (VCE) is a noninvasive diagnostic tool used to observe the small intestinal mucosa. We report a case of a 57-year-old woman with T2DM, treated with continuous subcutaneous insulin infusion using second-generation OmniPod patch pump, undergoing VCE (Given M2A; VCE Ltd, Yoqneam, Israel) for melena and anemia. During VCE, an abnormal interruption of communication between video capsule and its receiver occurred. Two hours after capsule ingestion, the patient activated the insulin pump infusion through the Personal Diabetes Manager (PDM) because she drank a sugary beverage for the first time after ingestion. Due to this, we decided to repeat VCE after the removal of the insulin pump and PDM: at this time, the capsule recorded for more than 10 h without any interruption. The video capsule and second-generation OmniPod patch pump use the same radio frequency and this may cause interference between these two devices. In patients using second-generation OmniPod patch pump undergoing VCE, we suggest to switch to intravenous insulin infusion or multiple daily injection or to use a different model of VCE, as MiRoCam (Intromedic, Seoul, Korea).

Platelet mean volume, distribution width, and count in type 2 diabetes, impaired fasting glucose, and metabolic syndrome: a meta-analysis

BACKGROUND

Platelet activation contributes to cardiovascular disease (CVD), the main complication of type 2 diabetes mellitus (T2DM) and pre-diabetic conditions. Mean platelet volume is an easy-to-measure platelet parameter that has been associated with CVD. We sought to assess mean platelet volume, platelet distribution width, and platelet count in T2DM, impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and metabolic syndrome.

METHODS

Web-based literature search (PubMed, EMBASE, and Web of Science) of studies published in English through June 2014 was performed to select case-control and cross-sectional studies that reported data on mean platelet volume, platelet distribution width, or platelet count in cases (subjects with T2DM, IFG, IGT, or metabolic syndrome) and noncases. Descriptive and quantitative information was extracted, and within-study standardized mean difference was estimated from means and standard deviations. Standardized mean differences across studies were synthesized using a random random-effects model, and subgroup analyses were performed on pre-specified study-level characteristics.

RESULTS

Thirty-nine studies were included. Compared with controls, mean platelet volume was significantly higher in T2DM (standardized mean difference, 95% confidence interval: 0.70, 0.50-0.91; N = 24,245), IFG (0.14, 0.02-0.26; N = 17,389) but not in metabolic syndrome (0.15, -0.24 to 0.55; N = 14,990). Platelet distribution width was wider in T2DM (0.93, 0.09-1.76; N = 471). Platelet count resulted higher in IFG (0.18, 0.12-0.24; N = 3960) and metabolic syndrome (0.39, 0.01-0.78; N = 4070). Only two studies included IGT.

CONCLUSIONS

Available data suggest that T2DM subjects tend to have higher mean platelet volume and platelet distribution width values, but nondifferent platelet count as compared with subjects without T2DM. Whether and how these morphometric changes contribute to CVD of T2DM or can be used as CVD biomarker awaits further investigation.

Atherosclerotic coronary plaque in subjects with diabetic neuropathy: the prognostic cardiovascular role of Charcot neuroarthropathy--a case-control study

The aim of this study was to investigate the severity of coronary artery disease (CAD) and the plaque composition in neuropathic type 2 diabetic subjects with and without Charcot neuroarthropathy (CN) undergoing multidetector computed tomography coronary angiography (MDCT-CA). The study was a single-center, observational, with unmatched case-control design. We selected 17 CN patients and 18 patients with diabetic neuropathy (DN) without CN. In all the patients, multidetector computed tomography was performed to assess the coronary artery calcium score (CACS) and degree of coronary artery stenosis. Patients were classified as positive in the presence of significant CAD if there was at least one stenosis >50 % on MDCT-CA. The invasive coronary angiography was performed in case of significant stenosis detected with MDCT-CA, both as reference to standard and eventually as treatment. Groups were matched for age, sex, and traditional CAD risk factors. As compared to DN individuals, CN exhibited higher rates of significant coronary stenoses (p = 0.027; OR 7.7 [1.3-43.5]). However, no significant differences were observed in the CACS, which reflects plaque burden, in the two groups (p = 0.759). No significant differences were observed comparing CACS distribution in all subjects for stenosis higher/equal or lower than 50 % (p = 0.320). Finally, no significant differences were observed comparing CACS distribution in CN and DN subjects for coronary stenoses higher/equal or lower than 50 %. Our results suggest that CN patients have a higher prevalence of severe coronary plaques compared to DN patients. Nevertheless, coronary plaques in CN patients did not exhibit an increased degree of calcification.

A case of esomeprazole-induced transient diabetes and hepatitis: the role of liver inflammation in the pathogenesis of insulin resistance

We describe a case report of a patient who developed transient type 2 diabetes after a drug-induced (esomeprazole) sub-acute hepatitis. This case evidences the pathophysiological relevance, also in humans, of liver inflammation in the pathogenesis of type 2 diabetes.

Cilostazol improves the response to ischemia in diabetic mice by a mechanism dependent on PPARγ

Cilostazol is effective for the treatment of peripheral ischemia. This compound has several beneficial effects on platelet aggregation, serum lipids and endothelial cells, and we recently found that it enhances collateral blood flow in the ischemic hind limbs of mice. Peroxisome proliferator-activated receptor (PPAR)γ, a receptor for thiazolidinediones, plays a role in angiogenesis. The aim of this work was to investigate the underlying molecular mechanisms and effects of cilostazol in a model of peripheral ischemia in diabetic mice. We induced diabetes in mice by streptozotocin (STZ) administration and studied ischemia-induced angiogenesis in the ischemic hind limbs of cilostazol-treated and untreated control mice. We found that perfusion recovery was significantly improved in treated compared with control diabetic mice. Interestingly, we found that the expression of PPARγ is reduced in ischemic tissues of diabetic mice. Furthermore, we discovered that local inhibition of the activity of this nuclear receptor decreased the angiogenic response to cilostazol treatment. Finally, we noted that this phenomenon is dependent on VEGF and modulated by PPARγ. Cilostazol administration enhances collateral blood flow in the ischemic hind limbs of STZ-induced diabetic mice through a PPARγ-dependent mechanism.

Oxidative stress in diabetes: implications for vascular and other complications

In recent decades, oxidative stress has become a focus of interest in most biomedical disciplines and many types of clinical research. Increasing evidence shows that oxidative stress is associated with the pathogenesis of diabetes, obesity, cancer, ageing, inflammation, neurodegenerative disorders, hypertension, apoptosis, cardiovascular diseases, and heart failure. Based on these studies, an emerging concept is that oxidative stress is the “final common pathway” through which the risk factors for several diseases exert their deleterious effects. Oxidative stress causes a complex dysregulation of cell metabolism and cell–cell homeostasis; in particular, oxidative stress plays a key role in the pathogenesis of insulin resistance and β-cell dysfunction. These are the two most relevant mechanisms in the pathophysiology of type 2 diabetes and its vascular complications, the leading cause of death in diabetic patients.

Effect of proinflammatory gene polymorphisms on the risk of Alzheimer's disease

BACKGROUND

A number of studies associate Alzheimer's disease (AD) with APOE polymorphism and alleles which favor the increased expression of immunological mediators such as cytokines or acute-phase proteins.

OBJECTIVE

In this study we evaluated the distribution of a set of functionally important polymorphisms of genes encoding prototypical inflammatory molecules in individuals with AD. We also investigated whether a synergistic effect of these proinflammatory gene polymorphisms on the risk of AD could be hypothesized.

METHODS

In a genetic association study that included 533 AD patients and 713 controls, the following gene polymorphisms were analyzed: C-reactive protein (CRP) 1059 G/C, interleukin 6 (IL6) -174 G/C, interleukin 1β (IL1B) -31 T/C, tumor necrosis factor α (TNF-α) -308 G/A, macrophage migration inhibitory factor (MIF) -173 G/C, monocyte chemoattractant protein 1 (CCL2) -2518 A/G, intercellular adhesion molecule 1 (ICAM1) 469 E/K, E-selectin (SELE) Ser128Arg, macrophage inflammatory protein 1α (CCL3) -906 T/A, matrix metalloproteinase 3 (MMP3) -1171 5A/6A and matrix metalloproteinase 9 (MMP9) -1562 C/T.

RESULTS

We found that IL6, IL1B, CCL2, CCL3, SELE, ICAM1, MMP3, and MMP9 gene polymorphisms were significantly and independently associated with AD. The association remained significant even after the Bonferroni correction. We also found that these proinflammatory polymorphisms were associated with different levels of risk for AD, depending on the number of high-risk genotypes concomitantly carried by a given individual.

CONCLUSION

Proinflammatory genotypes might influence the development and progression of AD exerting a potential synergistic effect.

Fields of application of continuous subcutaneous insulin infusion in the treatment of diabetes and implications in the use of rapid-acting insulin analogues

In western countries, diabetes mellitus, because of macrovascular and microvascular complications related to it, is still an important cause of death. Patients with type 1 diabetes mellitus (T1DM) have a six-time higher risk of mortality than healthy patients. Since the Diabetes Control and Complications Trial (DCCT) established how an intensive therapy is necessary to prevent diabetes mellitus complications, many studies have been conducted to understand which method is able to reach an optimal metabolic control. In the past 30 years continuous subcutaneous insulin infusion established/introduced as a validate alternative to multiple daily injections. Several trials demonstrated that, when compared to MDI, CSII brings to a better metabolic control, in terms of a reduction of glycated hemoglobin and blood glucose variability, hypoglycemic episodes and improvement in quality of life. Because of their pharmacokinetic and pharmacodynamic characteristics, rapid-action insulin analogues are imposed as best insulin to be used in CSII. The rapid onset and the fast reached peak make them better mimic the way how pancreas secretes insulin. CSII by pump is not free from issues. Catheter occlusions, blockages, clogs can arrest insulin administration. The consequent higher levels of glycemic values, can easily bring to the onset of ketoacidosis, with an high risk for patients' life. Aspart is a rapid analogue obtained by aminoacidic substitution. It is as effective as lispro and glulisine in gaining a good metabolic control and even better in reducing glucose variability. Some studies tried to compare rapid analogues in terms of stability. Obtained data are controversial. An in vivo study evidenced higher stability or glulisine, while studies in vitro highlighted a higher safety of aspart. Nowadays it is not possible to assess which analogues is safer. When the infusion set is changed every 48 hours equivalent rates of occlusions have been observed.

Nutrient infusion bypassing duodenum-jejunum improves insulin sensitivity in glucose-tolerant and diabetic obese subjects

The mechanisms of type 2 diabetes remission after bariatric surgery is still not fully elucidated. In the present study, we tried to simulate the Roux-en-Y gastric bypass with a canonical or longer biliary limb by infusing a liquid formula diet into different intestinal sections. Nutrients (Nutrison Energy) were infused into mid- or proximal jejunum and duodenum during three successive days in 10 diabetic and 10 normal glucose-tolerant subjects. Plasma glucose, insulin, C-peptide, glucagon, incretins, and nonesterified fatty acids (NEFA) were measured before and up to 360 min following. Glucose rate of appearance (Ra) and insulin sensitivity (SI), secretion rate (ISR), and clearance were assessed by mathematical models. SI increased when nutrients were delivered in mid-jejunum vs. duodenum (SI × 10⁴ min⁻¹·pM⁻¹: 1.11 ± 0.44 vs. 0.62 ± 0.22, P < 0.015, in controls and 0.79 ± 0.34 vs. 0.40 ± 0.20, P < 0.05, in diabetic subjects), whereas glucose Ra was not affected. In controls, Sensitivity of NEFA production was doubled in mid-jejunum vs. duodenum (2.80 ± 1.36 vs. 1.13 ± 0.78 × 10⁶, P < 0.005) and insulin clearance increased in mid-jejunum vs. duodenum (2.05 ± 1.05 vs. 1.09 ± 0.38 l/min, P < 0.03). Bypass of duodenum and proximal jejunum by nutrients enhances insulin sensitivity, inhibits lipolysis, and increases insulin clearance. These results may further our knowledge of the effects of bariatric surgery on both insulin resistance and diabetes.

Metformin improves endothelial function in type 1 diabetic subjects: a pilot, placebo-controlled randomized study

AIMS

Several studies have investigated the effects of metformin treatment in patients with type 1 diabetes mellitus (T1DM). No study has hitherto examined its effects on endothelial function in these patients. In this study we sought to evaluate the effect of metformin on endothelial function in type 1 diabetic patients.

METHODS

Forty-two uncomplicated T1DM patients were randomized in a placebo-controlled, double-blind, 6-month trial to treatment with either metformin or placebo. Glycometabolic and clinical parameters as well as flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD) of the right brachial artery were measured at baseline and at the end of the study. Glycaemic variability (GV, calculated from continuous glucose monitoring data) and a biomarker of oxidative stress [urinary 8-iso-prostaglandin F2α (PGF2α)] were also assessed.

RESULTS

Baseline data were similar in the two groups. Compared with placebo, metformin significantly reduced body weight [-2.27 kg (95% confidence interval: -3.99; -0.54); p = 0.012] whilst improved FMD [1.32% (0.30; 2.43); p = 0.013] and increased PGF2α [149 pg/mg creatinine (50; 248); p = 0.004]. Notably, the improvement of FMD did not correlate with the decrease of body weight (r(2)  < 1%). NMD, haemoglobin A1c, GV, daily insulin dose and other parameters did not significantly change after the treatment comparing the two groups.

CONCLUSIONS

Our pilot trial showed that, in uncomplicated type 1 diabetic subjects, metformin improved FMD and increased PGF2α, a marker of oxidative stress, irrespective of its effects on glycaemic control and body weight. Randomized, blinded clinical trials are needed to evaluate the benefits and risks of metformin added to insulin in type 1 diabetes.

Effects of GLP-1 on forearm vasodilator function and glucose disposal during hyperinsulinemia in the metabolic syndrome

OBJECTIVE

Patients with the metabolic syndrome (MetS) have impaired insulin-induced enhancement of vasodilator responses. The incretin hormone glucagon-like peptide 1 (GLP-1), beyond its effects on blood glucose, has beneficial actions on vascular function. This study, therefore, aimed to assess whether GLP-1 affects insulin-stimulated vasodilator reactivity in patients with the MetS.

RESEARCH DESIGN AND METHODS

Forearm blood flow responses to acetylcholine (ACh) and sodium nitroprusside (SNP) were assessed in MetS patients before and after the addition of GLP-1 to an intra-arterial infusion of saline (n = 5) or insulin (n = 5). The possible involvement of oxidative stress in the vascular effects of GLP-1 in this setting was investigated by infusion of vitamin C (n = 5). The receptor specificity of GLP-1 effect during hyperinsulinemia was assessed by infusing its metabolite GLP-1(9-36) (n = 5). The metabolic actions of GLP-1 were also tested by analyzing forearm glucose disposal during hyperinsulinemia (n = 5).

RESULTS

In MetS patients, GLP-1 enhanced endothelium-dependent and -independent responses to ACh and SNP, respectively, during hyperinsulinemia (P < 0.001 for both), but not during saline (P > 0.05 for both). No changes in vasodilator reactivity to ACh and SNP were seen after GLP-1 was added to insulin and vitamin C (P > 0.05 for both) and after GLP-1(9-36) was given during hyperinsulinemia (P > 0.05 for both). Also, GLP-1 did not affect forearm glucose extraction and uptake during hyperinsulinemia (P > 0.05 for both).

CONCLUSIONS

In patients with the MetS, GLP-1 improves insulin-mediated enhancement of endothelium-dependent and -independent vascular reactivity. This effect may be influenced by vascular oxidative stress and is possibly exerted through a receptor-mediated mechanism.

The oxidative modification of von Willebrand factor is associated with thrombotic angiopathies in diabetes mellitus

The thrombogenic activity of Von Willebrand factor (VWF) is proportional to its molecular size and inversely related to its proteolysis by ADAMTS-13. Oxidation of VWF severely impairs its proteolysis by the metalloprotease. This study was aimed at assessing in patients with type 1 and type 2 diabetes whether protein carbonyls, marker of oxidative stress, are associated with both the level and oxidation status of VWF as well as with micro- and macroangiopathic complications. Eighty-three diabetic patients (41 type 1 and 42 type 2 diabetic subjects) and their respective eighty-three healthy controls were studied after verifying the availability, through institutional databases, of clinical biochemistry records spanning at least 3 years. VWF and protein carbonyls were measured by immunoassays, whereas VWF multimers were studied by SDS-agarose gel electrophoresis. Type 2 diabetic subjects had higher levels of VWF antigen (VWF:ag), VWF activity (VWF:act) and plasma proteins’ carbonyls compared to both their controls and type 1 diabetic subjects. Moreover, high molecular weight VWF multimers and specific VWF-bound carbonyls were significantly increased in subjects with micro- and macro-angiopathic complications. In both type 1 and type 2 diabetic subjects, ADAMTS-13 activity was in the normal range. In a multivariable analysis, only VWF-bound carbonyls were significantly associated with any form of thrombotic angiopathy in the entire group of T1- and T2 diabetic patients. These data provide first evidence that not only high VWF levels but also its oxidation status and the presence of high molecular weight VWF multimers that are not observed in SDS-agarose gel electrophoresis of normal subjects are associated with thrombotic angiopathies in diabetes mellitus. These findings may help identify diabetic patients particularly at risk for these complications and elucidate a new pathophysiological mechanism of thrombotic angiopathies in this clinical setting.

Adaptive immunity, inflammation, and cardiovascular complications in type 1 and type 2 diabetes mellitus

Diabetes mellitus (DM) is a pandemics that affects more than 170 million people worldwide, associated with increased mortality and morbidity due to coronary artery disease (CAD). In type 1 (T1) DM, the main pathogenic mechanism seems to be the destruction of pancreatic β -cells mediated by autoreactive T-cells resulting in chronic insulitis, while in type 2 (T2) DM primary insulin resistance, rather than defective insulin production due to β -cell destruction, seems to be the triggering alteration. In our study, we investigated the role of systemic inflammation and T-cell subsets in T1- and T2DM and the possible mechanisms underlying the increased cardiovascular risk associated with these diseases.

Severity of coronary atherosclerosis in patients with a first acute coronary event: a diabetes paradox

AIMS

We aimed to compare coronary artery disease (CAD) at the time of a first acute coronary syndrome (ACS) in type II diabetic and non-diabetic patients by coronary angiography and by optical coherence tomography (OCT).

METHODS AND RESULTS

Two different patient populations with a first ACS were enrolled for the angiographic (167 patients) and the OCT (72 patients) substudy. Angiographic CAD severity was assessed by Bogaty, Gensini, and Sullivan scores, whereas collateral development towards the culprit vessel was assessed by the Rentrop score. Optical coherence tomography plaque features were evaluated at the site of the minimum lumen area (MLA) and of culprit segment. In the angiographic substudy, at multivariate analysis, diabetes was associated with both the stenosis score and the extent index (P = 0.001). Furthermore, well-developed collateral circulation (Rentrop 2-3) towards the culprit vessel was more frequent in diabetic than in non-diabetic patients (73% vs. 16%, P = 0.001). In the OCT substudy, at MLA site lipid quadrants were less and the lipid arc was smaller in diabetic than in non-diabetic patients (2.3 ± 1.3 vs. 3.0 ± 1.2; P = 0.03 and 198° ± 121° vs. 260° ± 118°; P = 0.03). Furthermore, the most calcified cross-section along the culprit segment had a greater number of calcified quadrants and a wider calcified arc in diabetic than in non-diabetic patients (1.7 ± 1.0 vs. 1.2 ± 0.9; P = 0.03 and 126° ± 95° vs. 81° ± 80°; P = 0.03). Superficial calcified nodules were more frequently found in diabetic than in non-diabetic patients (79 vs. 54%, P = 0.04).

CONCLUSIONS

In spite of potent pro-inflammatory, pro-oxidant and pro-thrombotic stimuli operating in type II diabetes, diabetic patients exhibit substantially more severe coronary atherosclerosis than non-diabetic patients at the time of a first acute coronary event. Better collateral development towards the culprit vessel, a predominantly calcific plaque phenotype and, probably, yet unknown protective factors operating in diabetic patients may explain these intriguing paradoxical findings.

Effect of ranolazine on arterial endothelial function in patients with type 2 diabetes mellitus

OBJECTIVE

To assess the effect of ranolazine on systemic vascular function in patients with type II diabetes mellitus (T2DM).

METHODS

We randomized 30 consecutive T2DM patients with no evidence of cardiovascular disease and no insulin therapy to receive one of the following 3 forms of treatment in a blinded fashion: ranolazine, 375 mg bid for 3 weeks (group 1); ranolazine, 375 mg bid for 2 weeks, followed by placebo bid for 1 week (group 2); placebo bid for 3 weeks (group 3). Flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD) of the right brachial artery were assessed at baseline and after 48 h, and 2 and 3 weeks.

RESULTS

FMD and NMD were similar among groups at baseline. Compared to the basal value, FMD significantly improved after 2 weeks in group 1 and in group 2 (p < 0.01 for both), but not in group 3. At 3 weeks, FMD remained improved, compared to baseline, in group 1 (p < 0.05), whereas returned to basal values in group 2 (p = 0.89 vs. baseline). No changes in NMD were observed in any group.

CONCLUSIONS

In this controlled study, ranolazine was able to improve endothelial function in T2DM patients.

Differential effects of heart rate reduction by atenolol or ivabradine on peripheral endothelial function in type 2 diabetic patients

OBJECTIVE

To assess whether reduction of heart rate (HR) has beneficial effects on endothelial function in patients with type 2 diabetes mellitus (T2DM).

DESIGN

Randomised, double-blind, placebo-controlled study.

SETTING

University hospital.

PATIENTS

66 T2DM patients without overt cardiovascular disease.

INTERVENTIONS

Patients were randomised to receive for 4 weeks, in addition to their standard therapy, one of the following treatments: atenolol (25 mg twice daily), ivabradine (5 mg twice daily) or placebo (1 tablet twice daily).

MAIN OUTCOME MEASURES

Systemic endothelial function, assessed by flow-mediated dilation (FMD); endothelium-independent vasodilation, assessed by nitrate-mediated dilation (NMD); cardiac autonomic function, assessed by HR variability (HRV).

RESULTS

61 patients completed the study (19, 22 and 20 patients in atenolol, ivabradine and placebo groups, respectively). Compared with baseline, HR was similarly reduced by atenolol (87±13 vs 69±9 bpm) and ivabradine (86±12 to 71±9 bpm), but not by placebo (82±10 vs 81±9 bpm) (p<0.001). FMD improved at follow-up in the atenolol group (4.8±1.7 vs 6.4±1.9%), but not in the ivabradine group (5.2±2.5 vs 4.9±2.2%) and in the placebo group (4.8±1.5 vs 4.7±1.7%) (p<0.01). NMD did not change significantly in any group. HRV parameters did not change in the placebo group; they, instead, consistently increased in the atenolol, whereas a mild increase in SDNNi was only observed in the ivabradine group. A significant correlation was found in the atenolol group between HR and FMD changes (r=-0.48; p=0.04).

CONCLUSIONS

Despite a comparable reduction in HR, atenolol, but not ivabradine, improved FMD in T2DM patients suggesting that changes in HR are by themselves unlikely to significantly improve endothelial function.

The recovery of platelet cyclooxygenase activity explains interindividual variability in responsiveness to low-dose aspirin in patients with and without diabetes

BACKGROUND

Interindividual variability in response to aspirin has been popularized as 'resistance'. We hypothesized that faster recovery of platelet cyclooxygenase-1 activity may explain incomplete thromboxane (TX) inhibition during the 24-h dosing interval.

OBJECTIVE

To characterize the kinetics and determinants of platelet cyclooxygenase-1 recovery in aspirin-treated diabetic and non-diabetic patients.

PATIENTS/METHODS

One hundred type 2 diabetic and 73 non-diabetic patients on chronic aspirin 100 mg daily were studied. Serum TXB(2) was measured every 3 h, between 12 and 24 h after a witnessed aspirin intake, to characterize the kinetics of platelet cyclooxygenase-1 recovery. Patients with the fastest TXB(2) recovery were randomized to aspirin 100 mg once daily, 200 mg once daily or 100 mg twice daily, for 28 days and TXB(2) recovery was reassessed.

RESULTS AND CONCLUSIONS

Platelet TXB(2) production was profoundly suppressed at 12 h in both groups. Serum TXB(2) recovered linearly, with a large interindividual variability in slope. Diabetic patients in the third tertile of recovery slopes (≥ 0.10 ng mL(-1) h(-1) ) showed significantly higher mean platelet volume and body mass index, and younger age. Higher body weight was the only independent predictor of a faster recovery in non-diabetics. Aspirin 100 mg twice daily completely reversed the abnormal TXB(2) recovery in both groups. Interindividual variability in the recovery of platelet cyclooxygenase activity during the dosing interval may limit the duration of the antiplatelet effect of low-dose aspirin in patients with and without diabetes. Inadequate thromboxane inhibition can be easily measured and corrected by a twice daily regimen.

The diabetic lung--a new target organ?

Several abnormalities of the respiratory function have been reported in patients with type 1 and type 2 diabetes. These abnormalities concern lung volume, pulmonary diffusing capacity, control of ventilation, bronchomotor tone, and neuroadrenergic bronchial innervation. Many hypotheses have emerged, and characteristic histological changes have been described in the "diabetic lung", which could explain this abnormal respiratory function. Given the specific abnormalities in diabetic patients, the lung could thus be considered as a target organ in diabetes. Although the practical implications of these functional changes are mild, the presence of an associated acute or chronic pulmonary and/or cardiac disease could determine severe respiratory derangements in diabetic patients. Another clinical consequence of the pulmonary involvement in diabetes is the accelerated decline in respiratory function. The rate of decline in respiratory function in diabetics has been found to be two-to-three times faster than in normal non-smoking subjects, as reported in longitudinal studies. This finding, together with the presence of anatomical and biological changes similar to those described in the aging lung, indicates that the "diabetic lung" could even be considered a model of accelerated aging. This review describes and analyses the current insight into the relationship of diabetes and lung disease, and suggests intensifying research into the lung as a possible target organ in diabetes.

Reduced respiratory muscle strength and endurance in type 2 diabetes mellitus

BACKGROUND

A restrictive lung function pattern is frequently observed in patients with diabetes mellitus (DM) and has been related to respiratory muscle dysfunction in type 1 DM or in mixed population. We aimed to verify whether such a relationship applies also to type 2 DM patients.

METHODS

The respiratory muscle function was explored in 75 non-smoking patients with type 2 DM without pulmonary or cardiac diseases and compared with that of 40 healthy non-smoking control subjects matched by age and sex. Maximal inspiratory and expiratory pressures (MIP, MEP) and maximum voluntary ventilation (MVV), which reflect respiratory muscle strength and endurance, respectively, were measured, and a complete respiratory function assessment was recorded.

RESULTS

Patients were in stable metabolic conditions and had, on average, normal total lung capacity and diffusing lung capacity for carbon monoxide. However, MIP and MVV were significantly reduced in comparison with those of control subjects. Both MIP/MEP and MVV significantly correlated with lung volumes and diffusing lung capacity for carbon monoxide. The multiple regression analysis identified age (beta coefficient = -0.238, p = 0.046), glycated haemoglobin (beta coefficient = -0.245, p = 0.047) and total lung capacity (beta coefficient = 0.430, p = 0.016) as independent correlates of MIP, whereas male sex (beta coefficient = 0.423, p = 0.004) and diabetic complications (beta coefficient = -0.248, p = 0.044) were independent correlates of MVV.

CONCLUSIONS

In type 2 DM, respiratory muscle strength was reduced and significantly related to lung volumes and quality of metabolic control, whereas impaired endurance of respiratory muscles prevailed in patients with microvascular complications.

Bariatric surgery versus conventional medical therapy for type 2 diabetes

BACKGROUND

Roux-en-Y gastric bypass and biliopancreatic diversion can markedly ameliorate diabetes in morbidly obese patients, often resulting in disease remission. Prospective, randomized trials comparing these procedures with medical therapy for the treatment of diabetes are needed.

METHODS

In this single-center, nonblinded, randomized, controlled trial, 60 patients between the ages of 30 and 60 years with a body-mass index (BMI, the weight in kilograms divided by the square of the height in meters) of 35 or more, a history of at least 5 years of diabetes, and a glycated hemoglobin level of 7.0% or more were randomly assigned to receive conventional medical therapy or undergo either gastric bypass or biliopancreatic diversion. The primary end point was the rate of diabetes remission at 2 years (defined as a fasting glucose level of <100 mg per deciliter [5.6 mmol per liter] and a glycated hemoglobin level of <6.5% in the absence of pharmacologic therapy).

RESULTS

At 2 years, diabetes remission had occurred in no patients in the medical-therapy group versus 75% in the gastric-bypass group and 95% in the biliopancreatic-diversion group (P<0.001 for both comparisons). Age, sex, baseline BMI, duration of diabetes, and weight changes were not significant predictors of diabetes remission at 2 years or of improvement in glycemia at 1 and 3 months. At 2 years, the average baseline glycated hemoglobin level (8.65±1.45%) had decreased in all groups, but patients in the two surgical groups had the greatest degree of improvement (average glycated hemoglobin levels, 7.69±0.57% in the medical-therapy group, 6.35±1.42% in the gastric-bypass group, and 4.95±0.49% in the biliopancreatic-diversion group).

CONCLUSIONS

In severely obese patients with type 2 diabetes, bariatric surgery resulted in better glucose control than did medical therapy. Preoperative BMI and weight loss did not predict the improvement in hyperglycemia after these procedures. (Funded by Catholic University of Rome; ClinicalTrials.gov number, NCT00888836.).

Therapeutic potential of high mobility group box-1 in ischemic injury and tissue regeneration

High-mobility group box-1 (HMGB1) is a nuclear protein that acts as a cytokine when released into the extracellular milieu by necrotic and inflammatory cells, and is involved in inflammatory responses and tissue repair. This protein is released passively during cellular necrosis by almost all cells that have a nucleus, but is also actively secreted by immune cells such as macrophages and monocytes. This cytokine plays a key role in mediating the local and systemic responses to several stimuli and might have therapeutic relevance. Indeed, vessel-associated stem cells, injected into the general circulation of dystrophic mice, migrate to sites of tissue damage in response to the HMGB1 signal, by a nuclear factor-κB dependent mechanism. Moreover, endogenous HMGB1 enhances angiogenesis and restores cardiac function in a murine model of myocardial infarction, and the exogenous administration of HMGB1 after myocardial infarction leads to the recovery of left ventricular function through the regeneration of cardiomyocytes. Finally, recent findings show that endogenous HMGB1 is crucial for ischemia-induced angiogenesis in diabetic mice and that HMGB1 protein administration enhances collateral blood flow in the ischemic hind limbs of diabetic mice through a VEGF-dependent manner. The mechanisms of action of this protein are complex and are not well known or defined. The objective of this review is to evaluate the data regarding the tissue regeneration effects of HMGB1, with the aim of providing practical considerations about this topic for the management of subjects affected by ischemic and degenerative diseases.

Effect of α-lipoic acid on platelet reactivity in type 1 diabetic patients

OBJECTIVE

Type 1 diabetes is associated with increased platelet reactivity. We investigated whether α-lipoic acid (ALA) has any effect on platelet reactivity in these patients.

RESEARCH DESIGN AND METHODS

We randomly assigned 51 type 1 diabetic patients to ALA (600 mg once daily) or placebo for 5 weeks. Platelet reactivity was evaluated by the PFA-100 method and by measuring CD41 and CD62 platelet expression. C-reactive protein (CRP) and 8-iso-prostaglandin F2α serum levels also were measured.

RESULTS

Baseline variables were similar in the two groups. After treatment, closure time was longer (P = 0.006) and CD62P platelet expression was lower, both before (P = 0.002) and after (P = 0.009) ADP stimulation in the ALA group compared with the placebo group. CRP and 8-iso-prostaglandin F2α levels showed no differences between the two groups.

CONCLUSIONS

Our data show that ALA reduces measures of platelet reactivity ex vivo in type 1 diabetic patients, independently of antioxidant or anti-inflammatory effects.

Pulmonary diffusing capacity for carbon monoxide: a marker of depressed hypercapnic drive in type 1 diabetes mellitus?

AIMS

Decreased chemosensitivity to hypercapnia, a common finding in Type 1 diabetes mellitus, seems related to autonomic neuropathy. We proposed to verify whether simple neuroautonomic cardiovascular tests or indexes of severity of diabetes and respiratory impairment can identify patients with such a dysfunction, but no clinical evidence of autonomic neuropathy.

METHODS

Forty patients with Type 1 diabetes, 20 with autonomic neuropathy according to the results of a standardized test battery, were studied and compared with 40 normal subjects matched by age and sex. Spirometry and pulmonary diffusing capacity for carbon monoxide were performed. The chemosensitivity to hypercapnia was tested by the rebreathing method.

RESULTS

There was no significant difference between patients with and without autonomic neuropathy in chemosensitivity to hypercapnia, as expressed by the ventilation response to increasing end-tidal pressure of carbon dioxide; however, it was lower in the whole group of patients with diabetes than in control subjects (1.71 ± 0.80 vs. 2.45 ± 1.11 l⁻¹ min⁻¹ mmHg, respectively, P=0.002). No significant correlation was found between ventilation response to increasing end-tidal pressure of carbon dioxide and the results of autonomic tests. In patients with diabetes mellitus, the ventilatory response to hypercapnia significantly correlated with pulmonary diffusing capacity for carbon monoxide (Spearman's rho=0.387, P=0.013) and this was the only variable significantly associated with ventilation response to increasing end-tidal pressure of carbon dioxide in a multiple regression model.

CONCLUSIONS

Chemosensitivity to hypercapnia was depressed in patients with diabetes mellitus, irrespective of autonomic neuropathy, in comparison with control subjects. The correlation with pulmonary diffusing capacity for carbon monoxide suggests that microcirculatory damage might contribute to depress the central chemosensitivity.

Assessment of the genetic effects of polymorphisms in the osteoprotegerin gene, TNFRSF11B, on serum osteoprotegerin levels and carotid plaque vulnerability

BACKGROUND AND PURPOSE

Osteoprotegerin (OPG) is a secretory glycoprotein which belongs to the tumor necrosis factor receptor family. Various mechanisms have been suggested by which calcification might alter atherosclerotic plaque stability, but the significance of this intimal calcification is controversial. High concentrations of OPG have been associated with the presence of vascular and cardiovascular diseases. This study was designed to assess the association between gene polymorphisms of the OPG gene (TNFRSF11B), the serum OPG level, and plaque stability in patients with carotid atherosclerosis.

METHODS

We studied 177 patients with internal carotid artery stenosis who underwent carotid endarterectomy and also 303 controls. Carotid endarterectomy samples removed from patients were assessed by immunohistochemistry. Concentrations of OPG were measured and gene polymorphisms were examined by polymerase chain reaction and restriction enzyme analysis and were compared, initially between patients with carotid atherosclerosis and controls, and subsequently between stable and unstable carotid plaques.

RESULTS

We found that the GG genotype of the T245G polymorphism, the CC genotype of the T950C polymorphism, and the CC genotype of the G1181C polymorphism were significantly higher in patients with carotid plaque than in controls (21.5% versus 10.9% , P<0.01; 15.8% versus 7.6%, P<0.01; and 20.3% versus 10.9%, P<0.01, respectively) and that these polymorphisms were associated with high serum OPG levels (4.02 [3.07] versus 2.94 [1.81] pmol/L; P<0.01), which were significantly higher in patients with unstable atherosclerotic plaques (5.86 [4.02] versus 3.53 [1.87] pmol/L; P<0.01).

CONCLUSIONS

The TNFRSF11B gene polymorphisms studied are associated with high serum OPG levels and might be potential markers for plaque instability.

Two-Step Autologous Grafting Using HYAFF Scaffolds in Treating Difficult Diabetic Foot Ulcers: Results of A Multicenter, Randomized Controlled Clinical Trial With Long-Term Follow-up

This study evaluated the efficacy and tolerability of an autologous tissue-engineered graft—a 2-step HYAFF autograft—in the treatment of diabetic foot ulcers compared with standard care. In all, 180 patients with dorsal or plantar diabetic foot ulcers (unhealed for ≥1 month) were randomized to receive Hyalograft-3D autograft first and then Laserskin autograft after 2 weeks (n = 90; treatment group) or nonadherent paraffin gauze (n = 90; control group). Efficacy and adverse events were assessed weekly for 12 weeks, at 20 weeks, and at 18 months. The primary efficacy outcome was complete ulcer healing at 12 weeks. Wound debridement, adequate pressure relief, and infection control were provided to both groups. At 12 weeks, complete ulcer healing was similar in both groups (24% of treated vs 21% controls). A 50% reduction in ulcer area was achieved significantly faster in the treatment group (mean 40 vs 50 days; P = .018). Weekly percentage ulcer reduction was consistently higher in the treatment group. At 20 weeks, ulcer healing was achieved in 50% of the treated group as compared with 43% of controls. Dorsal ulcers had a 2.17-fold better chance of wound healing per unit time following autograft treatment ( P = .047). In a subgroup with hard-to-heal ulcers, there was a 3.65-fold better chance of wound healing following autograft treatment of dorsal ulcers ( P = .035). Adverse events were similar in both groups. The study results demonstrated the potential of this bioengineered substitutes to manage hard-to-heal dorsal foot ulcers.

Combined atherogenic effects of celiac disease and type 1 diabetes mellitus

OBJECTIVE

Previous studies have shown a high cardiovascular risk in patients with autoimmune diseases, such as type 1 diabetes mellitus (T1DM). Conversely, few data are available about patients with celiac disease (CD). The aim of our study was to assess carotid intima-media thickness (c-IMT), in patients with T1DM, CD or both (T1DM+CD) as compared with age- and sex-matched healthy individuals (H).

METHODS

We enrolled 120 patients, 30 with T1DM, 30 with CD, 30 with T1DM+CD and 30 H. Clinical, metabolic and anthropometric data were collected. All T1DM patients were on insulin while all CD patients were on a gluten-free diet. c-IMT was evaluated by high frequency linear digital ultrasound.

RESULTS

c-IMT was significantly greater in patients with T1DM+CD than in patients with T1DM or CD (P<0.001 for both), while no difference was found between T1DM and CD. Moreover, c-IMT was greater in CD than in H (P<0.001). Glycemic control and disease duration were similar between T1DM+CD and T1DM. Lipid and anthropometric parameters were similar among groups. Furthermore, in a pooled multivariate analysis, only age and disease type were significantly correlated with c-IMT (P<0.001 for both).

CONCLUSION

Our study demonstrates that celiac patients have greater c-IMT as compared with healthy individuals. Thus, non-invasive monitoring of c-IMT in CD might be useful in preventing cardiovascular disease. Moreover, patients with T1DM+CD show more severe subclinical atherosclerosis as compared with those presenting T1DM or CD only, suggesting that the association of these autoimmune diseases might accelerate the atherosclerotic process.

Effects of bilio-pancreatic diversion on diabetic complications: a 10-year follow-up

OBJECTIVE

The surgical option could represent a valid alternative to medical therapy in some diabetic patients. However, no data are available on long-term effects of metabolic surgery on diabetic complications. We aimed to determine whether patients with newly diagnosed type 2 diabetes who underwent bilio-pancreatic diversion (BPD) had less micro- and macrovascular complications than those who received conventional therapy.

RESEARCH DESIGN AND METHODS

This was an unblinded, case-controlled trial with 10-years' follow-up, conducted from July 1998 through October 2009 at the Day Hospital of Metabolic Diseases, Catholic University, Rome, Italy. A consecutive sample of 110 obese patients (BMI >35 kg/m(2)) with newly diagnosed type 2 diabetes was enrolled. The study was completed by 50 subjects. The main outcome measure was long-term effects (10 years) of BPD versus those associated with conventional therapy on microvascular outcome, micro- and macroalbuminuria, and glomerular filtration rate (GFR). Secondary measures included macrovascular outcomes, type 2 diabetes remission, glycated hemoglobin, and hyperlipidemia.

RESULTS

Ten-year GFR variation was -45.7 ± 18.8% in the medical arm and 13.6 ± 24.5% in the surgical arm (P < 0.001). Ten-year hypercreatininemia prevalence was 39.3% in control subjects and 9% in BPD subjects (P = 0.001). After 10 years, all BPD subjects recovered from microalbuminuria, whereas microalbuminuria appeared or progressed to macroalbuminuria in control subjects. Three myocardial infarctions, determined by electrocardiogram, and one stroke occurred in control subjects. After the 10-year follow-up, coronary heart disease (CHD) probability was 0.22 ± 0.10 and 0.05 ± 0.04 in the medical and surgical groups, respectively (P < 0.001). Remission from type 2 diabetes was observed in all patients within 1 year of surgery. Surgical and medical subjects had lost 34.60 ± 10.25 and 0.38 ± 6.10% of initial weight at the 10-year follow-up (P < 0.001).

CONCLUSIONS

Renal and cardiovascular complications were dramatically reduced in the surgical arm, indicating long-term benefits of BPD on diabetic complications, at least in the case of morbid obesity with decompensated type 2 diabetes.

Severe leucopenia associated with Sitagliptin use

We report the case of a type 2 diabetes subject who developed severe leucopenia associated with treatment with the dipeptidil-peptidase 4 enzyme inhibitor Sitagliptin and highlights DPP4 inhibitors as a possible cause of unexplained hematolgical abnormalities in patients receiving DPP4-inhibitor treatment.

Inflammation-related effects of adjuvant influenza A vaccination on platelet activation and cardiac autonomic function

BACKGROUND

Inflammation, platelet reactivity and cardiac autonomic dysfunction increase the risk of cardiovascular events, but the relationships between these prognostic markers are poorly defined. In this study, we investigated the effect of an inflammatory stimulus (influenza A vaccine) on platelet activation and cardiac autonomic function.

METHODS

We measured serum C-reactive protein (CRP) and interleukin-6 levels, monocyte-platelet aggregates (MPAs) and monocyte/platelet receptor expression before and after adjuvant influenza A vaccination in 28 patients with type II diabetes (mean age 62.1 ± 8 years, 18 men). Twenty-four-hour Holter electrocardiogram was recorded 24 h before and after vaccination; heart rate variability (HRV) was assessed as a measure of cardiac autonomic function.

RESULTS

Inflammatory cytokines, MPA formation and monocyte/platelet receptor expression increased after vaccination. CRP was 2.6 ± 2.8 and 7.1 ± 5.7 mg L⁻¹ 48 h before and after vaccination, respectively (P < 0.0001). HRV parameters decreased after vaccination compared to baseline, with very low-frequency amplitude showing the most significant change (34.6 ± 11.8 and 31.0 ± 10.2 ms 48 h before and after vaccination, respectively; P = 0.002). A significant correlation was found between percentage changes in CRP levels and in most HRV variables, with the most significant correlations between changes in CRP levels and changes in standard deviation of all normal RR intervals (r = 0.43; P = 0.02).

CONCLUSIONS

Together with an inflammatory reaction, influenza A vaccine induced platelet activation and sympathovagal imbalance towards adrenergic predominance. Significant correlations were found between CRP levels and HRV parameters, suggesting a pathophysiological link between inflammation and cardiac autonomic regulation. The vaccine-related platelet activation and cardiac autonomic dysfunction may transiently increase the risk of cardiovascular events.

Effect of pioglitazone on systemic inflammation is independent of metabolic control and cardiac autonomic function in patients with type 2 diabetes

The aim of this article is to investigate the relation of the anti-inflammatory effect of pioglitazone with cardiac autonomic function and metabolic control in diabetic patients. In this prospective open label trial, 36 type 2 diabetic patients (age 60 ± 10, 20 M) without overt cardiovascular disease were randomized to add pioglitazone (30 mg) to their therapy or to continue standard therapy. C-reactive protein (CRP) serum levels, metabolic parameters and cardiac autonomic function (assessed by heart rate variability [HRV] on 24-h ECG Holter monitoring) were measured at baseline and after 3 months. Clinical and laboratory variables were similar in the two groups. No significant changes were observed after 3 months for metabolic and anthropometric parameters, except for a mild increase in HDL levels in the pioglitazone group only (P = 0.04 vs. controls). CRP levels decreased significantly at follow-up in the pioglitazone group (3.2 ± 1.97 vs. 2.37 ± 1.56 mg/l) but not in the control group (3.0 ± 1.92 vs. 3.93 ± 2.14 mg/l; P = 0.003). No differences were found in basal and follow-up HRV variables between the two groups. In type 2 diabetic patients pioglitazone exerts favourable effects on inflammation even after short-term therapy. This effect precedes those on metabolic and anthropometric parameters and is not associated with changes in cardiac autonomic function.

High-fat feeding stimulates endocrine, glucose-dependent insulinotropic polypeptide (GIP)-expressing cell hyperplasia in the duodenum of Wistar rats

AIMS/HYPOTHESIS

Incretins are hormones released by enteroendocrine cells in response to meals, depending upon absorption of nutrients. The present study aimed to elucidate the mechanisms through which a high-fat diet (HFD) induces insulin resistance and insulin hypersecretion by focusing on the effects on enteroendocrine cells, especially those secreting glucose-dependent insulinotropic polypeptide (GIP).

METHODS

Forty male Wistar rats, 4 months old, were randomised into two groups; one group received a chow diet and the other one received a purified tripalmitin-based HFD ad libitum. An OGTT was performed every 10 days and histological and immunofluorescence evaluations of the duodenum were obtained at 60 days from the beginning of the diets. Plasma glucose, insulin, GIP and glucagon-like peptide-1 (GLP-1) levels were measured. Immunofluorescence analysis of duodenal sections for pancreatic duodenal homeobox-1 (PDX-1), KI67, GLP-1, GIP and insulin were performed.

RESULTS

Compared with chow diet, HFD induced a progressive significant increase of the glucose, insulin and GIP responses to OGTT, whereas GLP-1 circulating levels were reduced over time. After 60 days of HFD, cellular agglomerates of KI67 and PDX-1 positive cells, negative for insulin and GLP-1 but positive for GIP staining, were found inside the duodenal mucosa, and apoptosis was significantly increased.

CONCLUSIONS/INTERPRETATION

With the limitation that we could not establish a causal relationship between events, our study shows that HFD stimulates duodenal proliferation of endocrine cells differentiating towards K cells and oversecreting GIP. The progressive increment of GIP levels might represent the stimulus for insulin hypersecretion and insulin resistance.

No protective effect of calcitriol on beta-cell function in recent-onset type 1 diabetes: the IMDIAB XIII trial

OBJECTIVE

We investigated whether supplementation of the active form of vitamin D (calcitriol) in recent-onset type 1 diabetes can protect beta-cell function evaluated by C-peptide and improve glycemic control assessed by A1C and insulin requirement.

RESEARCH DESIGN AND METHODS

Thirty-four subjects (aged 11-35 years, median 18 years) with recent-onset type 1 diabetes and high basal C-peptide >0.25 nmol/l were randomized in a double-blind trial to 0.25 microg/day calcitriol or placebo and followed-up for 2 years.

RESULTS

At 6, 12, and 24 months follow-up, A1C and insulin requirement in the calcitriol group did not differ from the placebo group. C-peptide dropped significantly (P < 0.001) but similarly in both groups, with no significant differences at each time point.

CONCLUSIONS

At the doses used, calcitriol is ineffective in protecting beta-cell function in subjects (including children) with recent-onset type 1 diabetes and high C-peptide at diagnosis.