Predictive value of diabetes mellitus for freedom from arrhythmia recurrence after cryoballoon-guided pulmonary vein isolation

Funding Acknowledgements

Type of funding sources: None.

Background

Diabetes mellitus (DM) has been identified to play an important role in the regulation of atrial fibrillation (AF). Data concerning the impact of DM on the development of individual arrhythmia substrates are still lacking.

Purpose

Therefore, the primary aim of this study was to examine the outcome of cryoballoon-guided pulmonary vein isolation (PVI) in patients (pts) suffering from DM and coexisting AF.

Methods

523 consecutive pts undergoing initial PVI using the 2nd generation cryoballoon were analysed. 273 pts (52%) suffered from paroxysmal AF (PAF) (51 ± 23.2 years old, 26% female), 250 pts (48%) from persistent AF (PERS) (63.9 ± 10.0 years old, 30% female) and 69 pts (13%) were diagnosed with DM (68 ± 19.6 years old, 30% female). Follow-up (FU) visits were performed at 3, 6 and 12 months including 7-day Holter ECGs. Primary endpoint was the first documented recurrence of any atrial arrhythmia after a 3 months blanking period (> 30 sec.).

Results

Within the observation period of 12 months AF recurrence occurred in 29% (n = 151 pts). Regardless of the coincidence of DM, PAF pts were significantly younger than those with PERS (p = 0.001). PAF pts additionally suffering from DM presented with a significantly higher risk for arrhythmia recurrence (p = 0.047). Multivariate analyses verified DM as a strong independent predictor for arrhythmia recurrence associated with a > 4 fold higher risk for recurrence after ablation (p = 0.009, hazard ratio (HR) 4.363, confidence interval (CI) 1.46-13.07). PERS pts showed a slightly increased rate of arrhythmia recurrence when additional DM was diagnosed. In these patients multivariate analyses revealed that DM was associated with a 43% higher risk for arrhythmia recurrence (p = 0.321, HR 1.143, CI 0.59-2.22). Beyond that, severe gender disparities were observed with female gender as independent predictor for arrhythmia recurrence (p = 0.027*, HR 1.927, CI 1.079-3.440).

Conclusions

DM has relevant implication for arrhythmia recurrence after PVI. More distinct effects were observed in PAF patients following AF ablation. This could be related to more severe arrhythmia substrates in PAF pts suffering from DM compared to PAF pts without additional DM and even more substantial structural changes in PERS. Thus, individual paths in ablation management are required in these pts with AF and coexisting DM.

Heart failure among people with Type 2 diabetes mellitus: real-world data of 289 954 people from a diabetes database

AIM

Comparing people with Type 2 diabetes mellitus with and without heart failure in terms of metabolic control, therapeutic regimen and comorbidities.

METHODS

The Prospective Diabetes Registry (DPV) is a longitudinal documentation system for demographics, medical care and outcome in people with diabetes mellitus. It consists of follow-up data from people with diabetes mellitus who have agreed to be recorded in the registry. Clinical data are submitted by general practitioners, specialists and clinics throughout Germany and Austria. Some 289 954 people with Type 2 diabetes mellitus (years 2000 to 2015) were analysed using demographic statistics and adjustment for confounders based on linear and logistic regression analysis.

RESULTS

People with Type 2 diabetes mellitus (ICD code: E11) and heart failure (ICD code: I50) (N = 14 723) were older, more often women and presented with longer diabetes duration compared with those without heart failure. After adjustment for age, gender and diabetes duration, people with heart failure showed lower HbA_1c , higher BMI and more intense insulin therapy. Analysis revealed that people with heart failure were more often treated with insulin, and more frequently received anti-hypertensives and lipid-lowering medication. They presented with lower systolic and diastolic BP. People with heart failure more frequently showed a history of comorbidities.

CONCLUSION

Heart failure is common in diabetes mellitus, but the prevalence in the DPV is lower frequent than expected. The reason for improved metabolic control in heart failure may be intensified therapy with insulin, lipid-lowering medication and anti-hypertensives in this cohort.

Beneficial Metabolic Effects of Duodenal Jejunal Bypass Liner for the Treatment of Adipose Patients with Type 2 Diabetes Mellitus: Analysis of Responders and Non-Responders

Implantation of a duodenal-jejunal endoluminal bypass liner (DJBL) has shown to induce weight loss and to improve metabolic parameters. DJBL is a reversible endoduodenal sleeve mimicking duodenal bypass while lacking risks and limitations of bariatric surgery.Effects on metabolic control, body mass parameters, appetite regulation, glucose tolerance, organ health, and lipid profile were determined in 16 morbidly overweight patients with type 2 diabetes mellitus. In addition, relevant hormones (leptin, ghrelin, gastric inhibitory peptide, glucagon-like peptide, and insulin) were measured by enzyme-linked immunosorbent assay (ELISA) and chemiluminescent microparticle immunoassay (CMIA) at 0, 1, 32, and 52 weeks post-implant following a mixed meal tolerance test. Lipoprotein subclasses were analysed by proton nuclear magnetic resonance (¹H NMR) spectrometry. DJBL provoked weight loss, a decrease in fat mass, and an improvement in insulin resistance and hepatic function in most but not all of the patients, but in the long term did not increase gut hormone fasting levels pointing to a combined effect of more than gut parameters alone. Lipidome analysis was done in 10 patients, allowing classification to responders and non-responders by reduction of sLDL-p subfraction; and to further analyse the atherogenic profile. Responders showed an overall more pronounced effect regarding improvement of HbA1c, BMI, and HOMA index.Implantation of a DJBL in obese type 2 diabetes patients does not per se lead to an improvement of the metabolic situation. Further analyses including larger cohorts have to be performed to identify responding patients, to better treat non-responders and to analyse the key effectors.

Beneficial Metabolic Effects of Duodenal Jejunal Bypass Liner for the Treatment of Adipose Patients with Type 2 Diabetes Mellitus: Analysis of Responders and Non-Responders

Implantation of a duodenal-jejunal endoluminal bypass liner (DJBL) has shown to induce weight loss and to improve metabolic parameters. DJBL is a reversible endoduodenal sleeve mimicking duodenal bypass while lacking risks and limitations of bariatric surgery.Effects on metabolic control, body mass parameters, appetite regulation, glucose tolerance, organ health, and lipid profile were determined in 16 morbidly overweight patients with type 2 diabetes mellitus. In addition, relevant hormones (leptin, ghrelin, gastric inhibitory peptide, glucagon-like peptide, and insulin) were measured by enzyme-linked immunosorbent assay (ELISA) and chemiluminescent microparticle immunoassay (CMIA) at 0, 1, 32, and 52 weeks post-implant following a mixed meal tolerance test. Lipoprotein subclasses were analysed by proton nuclear magnetic resonance (¹H NMR) spectrometry. DJBL provoked weight loss, a decrease in fat mass, and an improvement in insulin resistance and hepatic function in most but not all of the patients, but in the long term did not increase gut hormone fasting levels pointing to a combined effect of more than gut parameters alone. Lipidome analysis was done in 10 patients, allowing classification to responders and non-responders by reduction of sLDL-p subfraction; and to further analyse the atherogenic profile. Responders showed an overall more pronounced effect regarding improvement of HbA1c, BMI, and HOMA index.Implantation of a DJBL in obese type 2 diabetes patients does not per se lead to an improvement of the metabolic situation. Further analyses including larger cohorts have to be performed to identify responding patients, to better treat non-responders and to analyse the key effectors.

Effects of n-3 polyunsaturated fatty acids (PUFAs) on circulating adiponectin and leptin in subjects with type 2 diabetes mellitus

Recent evidence suggests that omega-3 polyunsaturated fatty acids [n-3 PUFAs: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)], improve insulin sensitivity in humans. In a double-blind, placebo-controlled, randomized, crossover study, we investigated the effects of EPA/DHA on paraoxonase-1 activity as well as fasting and postprandial levels of circulating adiponectin and leptin in 34 subjects with type 2 diabetes mellitus who received daily for 6 weeks either 2 g purified EPA/DHA or olive oil (placebo), separated by a 6 weeks washout. At the end of each treatment, measurements were performed in fasting state and 2, 4, and 6 h following a standardized high-fat meal (600 kcal). No significant differences in fasting and postprandial circulating adiponectin, leptin, and paraoxonase-1 activity were seen between n-3 PUFAs and placebo. Our data do not support an insulin sensitizing effect of n-3 PUFAs by means of influencing circulating adipocytokines in this population. Clinical Trial Register Number: NCT00328536.

Methylglyoxal impairs GLUT4 trafficking and leads to increased glucose uptake in L6 myoblasts

Methylglyoxal (MG) is a highly reactive dicarbonyl compound derived mainly from glucose degradation pathways, but also from protein and fatty acid metabolism. MG modifies structure and function of different biomolecules and thus plays an important role in the pathogenesis of diabetic complications. Hyperglycemia-associated accumulation of MG might be associated with generation of oxidative stress and subsequently insulin resistance. Therefore, the effects of MG on insulin signaling and on translocation of glucose transporter 4 (GLUT4) were investigated in the rat skeletal muscle cell line L6-GLUT4myc stably expressing myc-tagged GLUT4. Twenty four-hour MG treatment resulted in elevated GLUT4 presentation on the surface of L6 myoblasts and in an increased uptake of glucose even without insulin stimulation. Exogenously added MG neither effected IRS-1 expression nor IRS-1 phosphorylation. A decreased expression of Akt1 but not Akt2 and concomitantly increased apoptosis were detected following MG treatment. To exclude that oxidative stress caused by MG treatment leads to increased GLUT4 translocation, effects of pretreatment with 2 antioxidants were investigated. The antioxidant and MG scavenger NAC prevented the MG-induced GLUT4 translocation. In contrast, tiron, a well-known antioxidant that does not exert MG-scavenger function, had no impact on MG-induced GLUT4 translocation supporting the hypothesis of a direct effect of MG on GLUT4 trafficking. In conclusion, prolonged treatment with MG augments GLUT4 level on the surface of L6 myoblasts, at least in part through a higher translocation of GLUT4 from the intracellular compartment as well as a reduction of GLUT4 internalization, resulting in increased glucose uptake.

A randomized, double-blind, crossover, placebo-controlled trial of 6 weeks benfotiamine treatment on postprandial vascular function and variables of autonomic nerve function in Type 2 diabetes

AIMS

In a pilot study we suggested that benfotiamine, a thiamine prodrug, prevents postprandial endothelial dysfunction in people with Type 2 diabetes mellitus. The aim of this study was to test these effects in a larger population.

METHODS

In a double-blind, placebo-controlled, randomized, crossover study, 31 people with Type 2 diabetes received 900 mg/day benfotiamine or a placebo for 6 weeks (with a washout period of 6 weeks between). At the end of each treatment period, macrovascular and microvascular function were assessed, together with variables of autonomic nervous function in a fasting state, as well as 2, 4 and 6 h following a heated, mixed test meal.

RESULTS

Participants had an impaired baseline flow-mediated dilatation (2.63 ± 2.49%). Compared with the fasting state, neither variable changed postprandially following the placebo treatment. The 6 weeks' treatment with high doses of benfotiamine did not alter this pattern, either in the fasting state or postprandially. Among a subgroup of patients with the highest flow-mediated dilatation, following placebo treatment there was a significant postprandial flow-mediated dilatation decrease, while this effect was attenuated by benfotiamine pretreatment.

CONCLUSIONS

In people with Type 2 diabetes and markedly impaired fasting flow-mediated dilatation, a mixed test meal does not further deteriorate flow-mediated dilatation or variables of microvascular or autonomic nervous function. Because no significant deterioration of postprandial flow-mediated dilatation, microvascular or autonomic nervous function tests occurred after placebo treatment, a prevention of the postprandial deterioration of these variables with benfotiamine was not feasible.

Medical management for adults with Prader-Willi syndrome

BACKGROUND

Prader-Willi syndrome (PWS) is a genetic disorder characterized by morbid obesity resulting from insatiable appetite. Complications like diabetes mellitus or other cardiovascular diseases typically occur during lifetime. Lifestyle advice and education as well as limited caloric intake are the major concepts in assistance of PWS patients.

METHODS

A 12.9-month follow-up study, which included 8 formerly genetically diagnosed PWS patients, was conducted. Physical and laboratory examinations were done at the beginning and at the end of the follow-up. Improved medical care and lifestyle advice were given. The participants lived in an assisted living environment with a fixed daily schedule and limited caloric intake.

RESULTS

The group of patients consisted of manifest diabetics (n=6) as well as nondiabetics (n=2). Therapeutic concepts were simplified in 2 patients by switching from insulin to oral antidiabetics. The reduction in body weight was moderate, but attributable to a loss of fat mass. A significant reduction in blood cholesterol and triglyceride content was achieved along the observational period as well as a significant reduction of glycosylated hemoglobin (HbA1c) in the group of diabetic PWS patients. Systolic blood pressure improved during the study.

CONCLUSION

A combination of an assisted living environment following conservative treatments as well as consistent patient care improved the daily and medical situation of PWS patients. Weight loss and, as a consequence, improvements in terms of metabolic condition and blood pressure were observed. A combination of medical and daily routine management should be established in PWS patients to improve their quality of life.

Autologous stem cell therapy in the treatment of limb ischaemia induced chronic tissue ulcers of diabetic foot patients

BACKGROUND AND AIM

Despite improvements in surgical revascularisation, limitations like anatomical factors or atherosclerosis limit the success of revascularisation in diabetic patients with critical limb ischaemia. Stem cells were shown to improve microcirculation in published studies. The aim of this study was to evaluate safety, feasibility and efficacy of transplantation of bone marrow derived cellular products regarding improvement in microcirculation and lowering of amputation rate.

METHODS

Bone marrow mononuclear cells (BMCs) in comparison with expanded bone marrow cells enriched in CD90+ cells ('tissue repair cells', TRCs) were used in the treatment of diabetic ulcers to induce revascularisation. Diabetic foot patients with critical limb ischaemia without option for surgical or interventional revascularisation were eligible. Parameters examined were ABI, TcPO(2) , reactive hyperaemia and angiographic imaging before and after therapy.

RESULTS

Of 30 patients included in this trial, 24 were randomised to receive either BMCs or TRCs. The high number of drop-outs in the control group (4 of 6) led to exclusion from evaluation. A total of 22 patients entered treatment; one patient in the TRC group and two in the BMC group did not show wound healing during follow up, one patient in each treatment group died before reaching the end of the study; one after having achieved wound healing (BMC group), the other one without having achieved wound healing (TRC group). Thus, 18 patients showed wound healing after 45 weeks. The total number of applicated cells was 3.8 times lower in the TRC group, but TRC patients received significantly higher amounts of CD90+ cells. Improvement in microvascularisation was detected in some, but not all patients by angiography, TcPO(2) improved significantly compared with baseline in both therapy groups.

CONCLUSION

The transplantation of BMCs as well as TRCs proved to be safe and feasible. Improvements of microcirculation and complete wound healing were observed in the transplant groups.

[Diabetes and heart failure: a practically oriented critical appraisal]

Patients with type 2 diabetes have an increased risk for developing symptoms of heart failure. These can be accompanied by a reduction of left ventricular ejection fraction (HFREF, systolic heart failure) or by a preserved function (HFPEF, diastolic heart failure). The pathophysiology of both entities is distinct and involves impairment of myocardial metabolism and coronary circulation alike. Although diabetes and heart failure often coincide, the management of these patients particularly with respect to the specific benefits or possible hazards of antidiabetic treatment is vague. Therefore, from a pathophysiological as well as clinical viewpoint, 1) diabetic patients with symptoms of heart failure have to be differentiated regarding systolic as well as diastolic left ventricular function by echocardiography and tissue doppler imaging. 2) Heart failure in diabetic patients needs similar attention due to a prognosis and interactions. 3) Optimized blood glucose lowering in combination with improvement of other cardiovascular risk factors is evident for HFREF and is assumed to be beneficial for HFPEF. 4) Antidiabetic medication has to be specifically adapted for both entities. As prospective, controlled studies are scarce, future interventional studies should specifically focus on clinical outcome in diabetic patients with different entities of heart failure.

Oral glucose tolerance test and HbA₁c for diagnosis of diabetes in patients undergoing coronary angiography: [corrected] the Silent Diabetes Study

AIMS/HYPOTHESIS

The primary aim of this study was to compare the results of HbA(1c) measurements with those of an OGTT for early diagnosis of 'silent diabetes' in patients with coronary artery disease (CAD) undergoing angiography without prediagnosed diabetes. A secondary aim was to investigate the correlation between the extent of CAD and the glycaemic status of the patient.

METHODS

Data from 1,015 patients admitted for acute (n = 149) or elective (n = 866) coronary angiography were analysed. Patients with known diabetes were excluded from the study. Using the OGTT results, patients were classified as having normal glucose tolerance (NGT), impaired fasting glucose (IFG), impaired glucose tolerance (IGT) or diabetes. According to the results of the HbA(1c) measurements, patients were classified into three groups: normal (HbA(1c) <5.7% [<39 mmol/mol]), borderline (HbA(1c) 5.7-6.4% [39-47 mmol/mol]) and diabetes (HbA(1c) ≥6.5% [≥48 mmol/mol]).

RESULTS

Based on the OGTT, 513 patients (51%) were classified with NGT, 10 (1%) with IFG, 349 (34%) with IGT and 149 (14%) were diagnosed with diabetes. According to HbA(1c) measurements, 588 patients (58%) were classified as normal, 385 (38%) as borderline and 42 (4%) were diagnosed with diabetes. The proportion of patients with IGT and diabetes increased with the extent of CAD (IGT ρ = 0.14, p < 0.001, diabetes ρ = 0.09, p = 0.01). No differences in HbA(1c) were seen among the groups with different extents of CAD (p = 0.652).

CONCLUSIONS/INTERPRETATION

An OGTT should be performed routinely for diagnosis of diabetes in patients with CAD undergoing coronary angiography, since HbA(1c) measurement alone appears to miss a substantial proportion of patients with silent diabetes. A limitation of the study is that the OGTT was not performed before the angiography.

Heat shock protein 27 modification is increased in the human diabetic failing heart

Chronic conditions like diabetes mellitus (DM) leading to altered metabolism might cause cardiac dysfunction. Hyperglycemia plays an important role in the pathogenesis of diabetic complications including accumulation of methylglyoxal (MG), a highly reactive alpha-dicarbonyl metabolite of glucose degradation pathways and increased generation of advanced glycation endproducts (AGEs). The aim of this investigation was to study the extent of the MG-modification argpyrimidine in human diabetic heart and in rat cardiomyoblasts grown under hyperglycemic conditions. Left ventricular myocardial samples from explanted hearts of patients with cardiomyopathy with (n=8) or without DM (n=8) as well as nonfailing donor organs (n=6), and rat cardiac myoblasts H9c2 treated with glucose were screened for the MG-modification argpyrimidine. The small heat shock protein 27 (Hsp27) revealed to be the major argpyrimidine containing protein in cardiac tissue. Additionally, the modification of arginine leading to argpyrimidine and the phosphorylation of Hsp27 are increased in the myocardium of patients with DM. In H9c2 cells hyperglycemia leads to a decrease of the Hsp27-expression and an increase in argpyrimidine content and phosphorylation of Hsp27, which was accompanied by the induction of oxidative stress and apoptosis. This study shows an association between diabetes and increased argpyrimidine-modification of myocardial Hsp27, a protein which is involved in apoptosis, oxidative stress, and cytoskeleton stabilization.

Leptin decreases postprandially in people with type 2 diabetes, an effect reduced by the cooking method

Leptin modulates satiety and increases in obesity and type 2 diabetes mellitus in parallel with leptin resistance. Postprandial leptin regulation has been previously postulated to depend on meal composition, but data are controversial. The hypothesis of our study was that in people with type 2 diabetes mellitus, a postprandial leptin regulation exists that can be regulated not only by meal composition but also by the cooking method. In 20 inpatients with type 2 diabetes (mean age: 55.9 years), the acute effects of 2 meals, a high-heat-processed meal HHPM or a low-heat-processed meal LHPM, on leptin levels were studied on 2 different days in a randomized, crossover design. Both test meals had similar ingredients and differed only in the cooking method used. Parameters were measured after an overnight fast and at 2, 4, and 6 h postprandially. The HHPM induced a marked decrease in leptin levels, from 8 717+/-2 079 pg/ml at baseline to 6 788+/-1 598 pg/ml at 2 h postprandially (-1 929 pg/ml, -22%*), an effect significantly reduced by the LHPM, where values were 8 563+/-1 900 pg/ml at baseline and 7 425+/-1 591 pg/ml at 2 h postprandially (-1 138 pg/ml, -13%* (double dagger)) (*p<0.05 vs. baseline, (double dagger)p<0.05 vs. HHPM). Parameters of oxidative stress and blood AGEs increased only following the HHPM, while postprandial glucose, triglycerides, and insulin excursions were similar between meals. Postprandial leptin decreases following a HHPM meal in people with T2DM, an effect reduced by the cooking method.

High molecular weight adiponectin correlates positively with myeloperoxidase in patients with type 2 diabetes mellitus

Adiponectin (APN) is present in human plasma as a low molecular weight (LMW), a middle molecular weight (MMW) and a high molecular weight form (HMW). As a support to determine properties such as anti-atherogenic or atherogenic effects, recent clinical studies suppose to determine the ratio of each APN multimer to total APN but not the absolute plasma concentration of APN. In the present study, the correlation of APN and its multimers with myeloperoxidase (MPO), an enzyme with pro-inflammatory properties, was examined in patients with type 2 diabetes mellitus. MPO and APN serum levels were assessed in 49 patients with type 2 diabetes mellitus at the beginning and at the end of an anti-diabetic treatment. After treatment a significant increase in the ratio of HMW to total APN (from 0.43+/-0.16 to 0.59+/-0.14, p<0.05) was found. Before treatment, HMW-APN was correlated positively with MPO (r=0.314, p<0.05). Moreover, a positive correlation was observed between the increased HMW ratio and MPO during treatment (r=0.304, p<0.05). HMW-APN correlates positively with MPO in patients with type 2 diabetes. Therefore, HMW-APN may exert possible pro-inflammatory effects in type 2 diabetes.

[Diabetic cardiomyopathy--a type of coronary artery disease?]

Diabetic cardiomyopathy is a myocardial disease caused by diabetes mellitus unrelated to vascular and valvular pathology or systemic arterial hypertension. Clinical and experimental studies have shown that diabetes mellitus causes myocardial hypertrophy, apoptosis and necrosis, and increases interstitial tissue. The pathophysiology of diabetic cardiomyopathy is incompletely understood and several mechanistical approaches are under debate. Metabolic impairments like hyperglycemia, hyperlipidemia, hyperinsulinemia, and alterations in the cardiac metabolism lead to structural and functional changes which show cellular effects leading to increased oxidative stress, interstitial fibrosis, myocyte death, and disturbances in ion transport and homeostasis. Diastolic dysfunction which consecutively results in systolic dysfunction with increased left ventricular volume and reduced ejection fraction is an early diagnostic parameter. Treatment of diabetic cardiomyopathy does not differ from myocardiopathies of other etiologies and therefore has to follow the appropriate guidelines. Early intervention to reverse metabolic toxicity is the most effective method of prevention.

Platelet activation in diabetic microangiopathy

Platelet activation and hyperreactivity are known to be associated with a rapid development and progression of diabetic angiopathy. The present study attempts to clarify whether IDDM patients without diabetic complications have an increased platelet activation and whether in vivo platelet activation is altered in the presence of diabetic microangiopathy. Platelet activation was assessed by flow cytometry analysis in 50 healthy controls (c) and in 41 patients with insulin-dependent diabetes mellitus (IDDM type 1) who were screened for diabetic complications. Sixteen of these patients (0) showed no evidence of microangiopathic organ lesions as assessed by an established standard battery of clinical tests, whereas the other 25 patients had diabetes derived microvascular complications (dmc). Patients with macroangiopathy were ruled out. Platelet activation was evaluated by flow cytometric detection of four activation-dependent platelet surface markers (lysosomal GP53, thrombospondin, P-selectin and ligand-induced binding site-1 of GPIIb-IIIa). A higher percentage of thrombospondin-positive platelets was detected in the IDDM patients without complications: 8.6 +/- 0.9% (0) vs 6.1 +/- 0.4% (c) vs 5.4 +/- 0.4% (dmc), P < 0.05, respectively. A decrease in GP53-, P-selectin-, and LIBS-1-positive platelets was observed in the IDDM group with dmc: for GP53 17.4 +/- 1.0% (dmc) vs 23.4 +/- 1.0% (c), P < 0.05; for P-selectin 5.5 +/- 0.6% (dmc) vs 8.0+/-0.7% (c), P < 0.01 and for LIBS-1 8.3 +/- 0.9% (dmc) vs 15.8 +/- 1.3% (c), P < 0.01. No differences in these markers were found in controls and IDDM patients without complications. In addition, no correlations were found between the glucose metabolism and platelet activation. These findings indicate (i) that the platelet system is pre-activated in IDDM , and (ii) that an increased consumption of activated platelet may occur in the vessels of IDDM patients with diabetic microangiopathy.

Wound therapy with autologous bone marrow stem cells in diabetic patients with ischaemia-induced tissue ulcers affecting the lower limbs

Previous studies suggest that autologous transplantation of bone marrow mononuclear cells is safe and effective in inducing therapeutic angiogenesis in patients with peripheral arterial occlusive disease (PAOD). Here we discuss a multidisciplinary approach to treating PAOD with a focus on the use of angiological diagnostic tools. We conclude that our autologous stem cell therapy is working in this patient and it is a potential new therapeutic option for diabetic patients with chronic foot ulcers induced by critical limb ischaemia.

Angina intensity is not different in diabetic and non-diabetic patients with acute myocardial infarction

BACKGROUND

Diabetic patients with acute myocardial infarction (AMI) may have diminished pain or a higher frequency of asymptomatic infarctions. This appears to be a common clinical perception.

METHODS

Data from two registries of AMI patients presenting in hospital (MITRA PLUS with 18786 patients; North German Registry, NGR, 1042 patients with detailed symptom interviews) were analyzed concerning symptoms of acute myocardial infarction in patients with diabetes mellitus (DM) and without diabetes (non-DM).

RESULTS

DM patients were significantly older and more often female than non-DM. There were no differences in the frequency of pre-infarction angina between DM and non-DM (Mitra Plus). In NGR, severe angina during AMI occurred in 49.8% of DM and 46.3% of non-DM (n. s.). No chest pain was reported in 16.9% of DM and 15.0% of non-DM (n. s.). Extra-thoracic pain, dizziness, nausea, sweating, palpitations, radiation of angina and localization of radiating pain was not different between DM and non-DM patients. Severe dyspnea occurred in 29.5% of DM and 19.5% of non-DM patients (p = 0.003).

CONCLUSIONS

Apart from a higher frequency of severe dyspnea in diabetics, there appears to be no difference in the clinical symptoms of AMI patients with and without diabetes mellitus. AMI with little or no angina was also frequently found in non-diabetics. In the hospital, diabetics with suspected AMI do not appear to need a special judgement of symptoms. This could accelerate access of diabetics to standard therapeutic procedures.

Genetic variation of the platelet- surface integrin GPIIb-IIIa (PIA1/A2-SNP) shows a high association with Type 2 diabetes mellitus

AIMS/HYPOTHESIS

The gene encoding the beta(3)-subunit (GPIIIa) of the platelet alpha(2)beta(3)-integrin (fibrinogen receptor) shows a polymorphism PlA1/A2 with the A2 allele putatively associated with an increased risk of acute ischaemic events. This study investigated whether Type 2 diabetes as a particular macrovascular risk factor associates with the thrombogenic PIA2 genotype.

METHODS

The PlA genotype was determined in 112 consecutive Type 2 diabetic patients additionally classified according to the presence of macrovascular disease. Forty-four non-diabetic patients with angiografically documented cardiovascular disease (CAD/ AMI) and a further 59 non-diabetic subjects with no angiografical signs of CAD were investigated as genomic background control (n=103). PIA-genotyping was carried out by standard restriction fragment length analysis (RFLA) of PCR amplified lymphocyte template DNA.

RESULTS

The overall allelic PlA2- prevalence accounted to 34.8% (39/112) in diabetic patients as compared to 14.6% (15/103) in non-diabetic patients [OR 3.1 (1.6-6.1), p<0.01]. This odds ratio increased to 7.0 (2.5-19.7), (p<0.01) in subjects free of criteria of macrovascular disease. In non-diabetic control subjects without CAD there was an allelic PIA2 frequency of 10.2% (6/59) as compared to 20.5% (9/44) in patients with CAD and a history of AMI being less than either diabetes subgroup. The PIA2 prevalence in the subgroup of diabetes patients with macrovascular complications did not differ from the respective value in patients without macrovascular disease. [29.0% (20/69) vs. 44.2% (19/43)].

CONCLUSION/INTERPRETATION

This study confirms a trendwise association of PlA2 with severe coronary artery disease, but rather suggests an even stronger, highly significant association with the metabolic condition of Type 2 diabetes mellitus. This justifies the speculation that pathways dependent on the platelet alpha(2)beta(3) integrin physiology could be implicated in the pathogenesis of Type 2 diabetes which lends further support to the "common soil" hypothesis of diabetes and vascular disease.

Leukocyte apoptosis in whole blood involves platelet-dependent coaggregation

BACKGROUND

Activated leukocytes and platelet-leukocyte interaction are involved in the pathogenesis of thrombotic and inflammatory events. Because apoptosis is a prerequisite for the successful resolution of an inflammatory response, we investigated the amount of apoptotic peripheral blood leukocytes (PBLs) in whole blood and their possible functional relation with the platelet-leukocyte interaction by a flow cytometric assay using APO 2.7 antibody for the detection of apoptosis

METHODS

Thirty healthy subjects volunteered for the study. PBL apoptosis in seven volunteers was induced by phorbol 12-myristate 13-acetate or while standing at rest.

RESULTS

Apoptosis was observed in all types of leukocytes (0.7% neutrophils, 1.5% monocytes, and 0.3% lymphocytes). Apoptosis was found predominantly in platelet and leukocyte coaggregates (<1% of nonaggregated leukocytes vs. 9% of platelet and leukocyte coaggregates). This phenomenon was even more pronounced after induction of leukocyte apoptosis in vitro (66% of platelet and leukocyte coaggregates).

CONCLUSIONS

Apoptosis and platelet-leukocyte interaction seemed to be closely related phenomena, and apoptotic leukocytes seemed to trigger adhesion and, hence, activation of platelets. Because platelet-leukocyte interaction is involved in the pathogenesis of thrombotic events, apoptotic leukocytes may constitute an additional prothrombotic trigger.

Macrovascular disease in diabetes: current status

Clearly, macrovascular complications are the prognosis limiting problem of diabetes patients which consecutively account for the majority of socio-economic burden of the disease. The overall morbidity and mortality development does not indicate improvement hallmarking better or at least adequate care for these patients. Possible explanations address the late detection problem of a clinically silent disease onset as well as unrecognised multiple comorbid conditions all of which end-up with endothelial dysfunction as representation of the so called "functional atherosclerosis" and blood hyperresponsiveness. Here, we describe new experimental aspects of the early atherosclerosis development focussing inflammation as one driving pathogenetic force for the evolution of the complicated lesion type in diabetes. However, emphasis is put on the view that inflammation, atherogenesis and thrombogenesis are severely crosslinked by soluble and cellular adhesion molecules. From a diagnostic point of view genomic detection of risk associated genes opens both the vision of early identification of high risk individuals and the targeting of drug intervention based on conditioned responsiveness. By using available drugs and evidence based risk factor intervention strategies a plea is made for a multimodal therapeutic approach fitted to the individual patient's needs aiming at endpoint reduction. This corresponds to the recent releases of guidelines from nearly all vascular medicine related scientific societies. Diabetes is a vascular disease!

Evaluation of an antibody-based genotype classification of the platelet fibrinogen receptor (GPIIb/IIIa)

Platelet membrane glycoprotein (GP) IIb/IIIa is the central molecule in platelet adhesion and aggregation by high-affinity binding of fibrinogen. Polymorphism of the beta chain of the receptor, especially the GPIIIa-proline33 allele [HPA-1b, Zwb, PI(A2)], has been suggested to be associated with a variety of vascular diseases, such as coronary stenosis, myocardial infarction, cerebral ischemia, or venous thrombosis. Using clinical chemistry standards, we evaluate a flow cytometric whole-blood, antibody-based method to determine the genotype [PI(A1A1), PI(A1A2), PI(A2A)] versus polymerase chain reaction (PCR)-based DNA restriction fragment length analysis in 220 individuals. Both homozygous and heterozygous genotypes differ in the expression of binding sites for the monoclonal antibody, SZ21. Agreement between the two methods was achieved in 187 cases, which reflects a test validity of 85%, a sensitivity of 83.6%, and a specificity of 85.4%. We conclude that flow cytometry is reliable for classifying the PI(AX) genotype. The performance characteristics are easy, fast, and cheap (genomics by proteomics). These features make it suitable for screening patients and broad populations for the future risk of cardiovascular ischemic events.

Response of human monocyte-derived dendritic cells to immunostimulatory DNA

Activated dendritic cells (DC) are of key importance for the initiation of primary immune responses and represent promising tools for immunotherapies in humans. Since DNA containing CpG motifs have been described as potent immunostimulatory (IS) adjuvants for murine DC, we here studied maturation and stimulation of functional activity in human monocyte-derived DC (MODC) in response to several immunostimulatory oligodeoxynucleotides (IS-ODN) and plasmid DNA (IS-PL). We show that exposure of MODC to IS-PL, but not IS-ODN, induced a dose-dependent strong up-regulation of HLA class II and co-stimulatory molecules (CD80, CD86), similar to that observed after treatment with TNF-alpha. Functional activity was assessed by the detection of increased secretions of IL-6 and IL-12(p75) following treatment with IS-PL. In addition, IS-PL-stimulated MODC acquired a high T cell-stimulatory capacity. T cells stimulated by tetanus toxoid-pulsed, IS-PL-matured MODC were significantly more frequently IFN-gamma positive (25.2+/-2.7%) as compared to TNF-alpha-treated MODC (15.4+/-1.4%), indicating a strong activation of Th1 lymphocytes. In conclusion, we demonstrate that human MODC are activated by IS-PL but not IS-ODN previously used as adjuvants in animal models. The Th1-like immune response observed after stimulation with IS-PL-treated DC suggests that preincubation of human MODC with IS-PL or coimmunization with IS-PL may represent an useful approach to generate strongly activated human MODC for several therapeutic applications such as DC-based tumor immunotherapy.

Platelet activation in diabetic cardiovascular autonomic neuropathy

AIMS

Platelet activation is known to be associated with arrhythmic effects in myocardial ischaemia. The present study attempts to clarify whether diabetic cardiovascular autonomic neuropathy (CAN) is associated with intravascular platelet activation.

METHODS

Platelet activation was assessed by flow cytometry analysis in 30 patients with Type 1 diabetes mellitus screened for diabetic complications. Fifteen patients showed evidence of CAN as assessed by a battery of standard cardiovascular autonomic reflex tests. Fifteen patients without CAN were then selected as a matched control group. Platelet activation was assessed by flow cytometric detection of activation-dependent platelet membrane antigens (P-selectin (CD62), thrombospondin, lysosomal GP53 (CD63) and ligand-induced binding site-1 of GPIIb/IIIa (LIBS-1)).

RESULTS

Significantly more activated platelets were detected in the patients with CAN showing 20.9% (coefficient of variation (CV) 44%) CD63+ (vs. 17.2% (CV 19%) in controls, P < or = 0.05), 6.4% (CV 87%) CD62+ (vs. 4.1% (CV 37%), P < or = 0.05), and 6.7% (CV 55%) thrombospondin+ (vs. 4.6% (CV 39%), P < or = 0.01) platelets, respectively. LIBS-1 on platelets was not significantly different between patients with and without CAN. No correlation was found between glucose metabolism and platelet activation.

CONCLUSIONS

Cardiovascular autonomic neuropathy is associated with platelet activation in Type 1 diabetes mellitus. The high platelet activation may reflect an increased prothrombotic state in diabetic cardiovascular autonomic dysfunction.

Circulating platelets show increased activation in patients with acute cerebral ischemia

Platelet activation plays a central role in acute arterial stenosis as has been shown in coronary heart disease. Likewise it can be assumed to be of importance in the evolution of acute cerebral ischemia (ACI), particularly in patients with large vessel disease. Flow cytometric detection of platelet adhesion molecules as a marker of platelet activation in a group of patients with ACI and different etiologies has not been evaluated. In 72 patients with ACI and 72 controls, the exposure of activation-dependent adhesion molecules was determined using flow cytometry after immunostaining with monoclonal antibodies against CD 62, CD 63 and thrombospondin. The extent of platelet activation differed as a function of the etiology of ACI: platelets from patients with atherosclerosis of brain-supplying arteries expressed significantly more activation markers than did controls, whereas patients with cardioembolic stroke did not. By analyzing platelet adhesion molecules it is possible to describe platelet activation profiles in patients with acute cerebral ischemia. This diagnostic procedure will be useful for monitoring individualized anti-platelet therapy and may enable distinguishing different subgroups of stroke patients.

[The heart and metabolic syndrome]

Most people with the Metabolic Syndrome die from thrombotic complications superimposed to degenerative arterial vascular lesions, mostly myocardial infarction. Type-2-Diabetes is a risk factor per se for such complications, but often clusters with dyslipoproteinemia, hypertension and obesity. This is referred to as "Metabolic Syndrome" and often operates on a genetically programmed susceptibility which accelerates the pathogenesis of coronary artery disease in front of a much wider diabetes specific cardiopathy. From a pathophysiological point of view none of these associated risk factors explains the pathogenetic series of events leading to the precipitation of an occlusive thrombus at sites of complicated coronary plaques. In patients with the Metabolic Syndrome the coagulation system is switched towards a prethrombotic state, involving increased plasmatic coagulation, diminished fibrinolysis, decreased endothelial thromboresistance and predominantly platelet hyperreactivity ("diabetic thrombocytopathy"). Some of these factors are associated with an increased coronary risk (e.g. fibrinogen, PAI-1, platelets), but are also directly linked to the pathogenesis of "atherothrombosis". Altered cardiac remodelling together with adhesion and coagulation mechanisms appears suitable to explain decreased functional performance of infarcted organs, decreased success of acute (reduced fibrinolytic response, no reflow phenomenon) and longterm intervention strategies for vessel patency (PTCA, CABG) in Diabetes. Glucose adjustment alone will not adequately neutralize these complex mechanisms, but in the situation of myocardial infarction eumetabolization with parenteral glucose-insulin-potassium infusion appears mandatory similar to non-diabetics. On the longterm a multidimensional interventional repertoire is required particularly in patients with the Metabolic Syndrome including antihypertensive, antidyslipoproteinemic and antithrombotic drugs, customized according to the individual patients needs as assessed by early diagnostic measures ("early secondary prevention").