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Background. Heat shock proteins (Hsp) act as intracellular chaperones and in addition are used as adjuvant in vaccines of peptides complexed with recombinant Hsp. By interacting with autologous peptides, Hsp may promote the induction of autoimmune reactivity. Objective. Here, we analysed whether the effect of Hsp on macrophages is modulated by insulin peptides known to interact with Hsp. Results. Combinations of the 70 kDa Hsp DnaK with peptide B11-23 from the core region of the proinsulin B-chain induced the release of the inflammatory mediators interleukin-6, tumor necrosis factor α, and interleukin-1β from cells of human and murine macrophage lines. In parallel, there was high-affinity binding of B11-23 to DnaK. DnaK mixed with peptides from other regions of the insulin molecule did not stimulate cytokine secretion. DnaK alone induced little cytokine production, and peptides alone induced none. Conclusion. The macrophage-stimulating potential of Hsp70 family proteins when combined with the proinsulin B-chain peptide B11-23 may contribute to the immunodominance of this peptide in the development of beta cell-directed autoimmunity in type 1 diabetes.

Background Insulin shares a limited physiological concentration range with other endocrine hormones. Not only too low, but also too high systemic insulin levels are detrimental for body functions. Main body The physiological function and clinical relevance of insulin are usually seen in association with its role in maintaining glucose homeostasis. However, insulin is an anabolic hormone which stimulates a large number of cellular responses. Not only too low, but also excess insulin concentrations are detrimental to the physiological balance. Although the glucoregulatory activity of insulin is mitigated during hyperinsulinemia by dampening the efficiency of insulin signaling (“insulin resistance”), this is not the case for most other hormonal actions of insulin, including the promotion of protein synthesis, de novo lipogenesis, and cell proliferation; the inhibition of lipolysis, of autophagy-dependent cellular turnover, and of nuclear factor E2-related factor-2 (Nrf2)-dependent antioxidative; and other defense mechanisms. Hence, there is no general insulin resistance but selective impairment of insulin signaling which causes less glucose uptake from the blood and reduced activation of endothelial NO synthase (eNOS). Because of the largely unrestricted insulin signaling, hyperinsulinemia increases the risk of obesity, type 2 diabetes, and cardiovascular disease and decreases health span and life expectancy. In epidemiological studies, high-dose insulin therapy is associated with an increased risk of cardiovascular disease. Randomized controlled trials of insulin treatment did not observe any effect on disease risk, but these trials only studied low insulin doses up to 40 IU/day. Proof for a causal link between elevated insulin levels and cardiovascular disease risk comes from Mendelian randomization studies comparing individuals with genetically controlled low or high insulin production. Conclusions The detrimental actions of prolonged high insulin concentrations, seen also in cell culture, argue in favor of a lifestyle that limits circadian insulin levels. The health risks associated with hyperinsulinemia may have implications for treatment regimens used in type 2 diabetes.

The association of habitual coffee consumption with a lower risk of diseases, like type 2 diabetes mellitus, chronic liver disease, certain cancer types, or with reduced all-cause mortality, has been confirmed in prospective cohort studies in many regions of the world. The molecular mechanism is still unresolved. The radical-scavenging and anti-inflammatory activity of coffee constituents is too weak to account for such effects. We argue here that coffee as a plant food has similar beneficial properties to many vegetables and fruits. Recent studies have identified a health promoting mechanism common to coffee, vegetables and fruits, i.e., the activation of an adaptive cellular response characterized by the upregulation of proteins involved in cell protection, notably antioxidant, detoxifying and repair enzymes. Key to this response is the activation of the Nrf2 (Nuclear factor erythroid 2-related factor-2) system by phenolic phytochemicals, which induces the expression of cell defense genes. Coffee plays a dominant role in that regard because it is the major dietary source of phenolic acids and polyphenols in the developed world. A possible supportive action may be the modulation of the gut microbiota by non-digested prebiotic constituents of coffee, but the available data are still scarce. We conclude that coffee employs similar pathways of promoting health as assumed for other vegetables and fruits. Coffee beans may be viewed as healthy vegetable food and a main supplier of dietary phenolic phytochemicals.

It is still an enigma why T cell autoreactivity in type 1 diabetes targets few beta cell antigens only. Among these, one primary autoantigen is pro(insulin). Autoimmune T cells preferentially recognise three epitopes on the proinsulin molecule, of which the peptide region B:11-23 is the dominant one. Interestingly, the three regions superimpose with binding sites of the chaperone hsp70, the region B:11-23 being the strongest binding one. Absence of an intact core region B:15-17 prevents autoimmune diabetes in NOD as well as binding of hsp70. A role of hsp70 in selecting autoimmune epitopes is supported by the ability of this and other chaperones to deliver bound peptides to MHC class I and II molecules for efficient antigen presentation. Binding of hsp70 to receptors on antigen presenting cells such as TLR4 results in costimulatory signals for T cell activation. Strongest effects are seen for the mixture of hsp70 with the peptide B:11-23. Thus, hsp70 may assist in proinsulin epitope selection and efficient presentation to autoreactive T cells. The concept of chaperone guided immune reactivity may also apply to other autoimmune diseases.

T cell-directed immunosuppression only transiently delays the loss of β cell function in recent-onset type 1 diabetes. We argue here that the underlying disease process is carried by innate immune reactivity. Inducing a non-polarized functional state of local innate immunity will support regulatory T cell development and β cell proliferation.

OBJECTIVE We related organ-specific autoantibodies, including diabetes-associated autoantibodies (DAAs) and non-DAAs to systemic cytokines/chemokines in type 1 and type 2 diabetes. RESEARCH DESIGN AND METHODS From the European Action LADA (latent autoimmune diabetes in adults) cohort, patients with adult-onset type 1 diabetes (n = 80, of whom 50 had LADA and 30 had classic type 1 diabetes) and type 2 diabetes (n = 626) were analyzed for DAAs (GAD antibody [GADA], IA-2 antigen, islet cell antibody, and zinc transporter T8), non-DAAs (transglutaminase, thyroid peroxide autoantibodies, parietal cell antibodies), and 10 immune mediator concentrations (measured by LUMINEX). RESULTS Type 1 diabetes patients (whether having classic type 1 diabetes or LADA), apart from their clinical phenotype, could not be distinguished by either autoantibodies (both DAAs and non-DAAs) or immune mediators. In type 1 diabetes, most immune mediators (9 of 10) were negatively correlated with DAA titers. Type 2 diabetes patients, who by definition were without DAAs, had fewer non-DAAs (P < 0.0005), but had higher levels of proinflammatory immune mediators, especially compared with patients with type 1 diabetes who had high GADA titers (interleukin [IL]-6 [P < 0.001], soluble E-selectin [P < 0.01], and IL-1 receptor antagonist [P = 0.052], for trend). CONCLUSIONS Patients with type 1 diabetes had more DAAs and non-DAAs than did those with type 2 diabetes, whereas the frequency and nature of these autoantibodies was broadly similar in classic type 1 diabetes and LADA. Systemic immune mediator levels, in the main, were negatively correlated with DAA titers, and, for some, were higher in patients with type 2 diabetes, especially when compared with patients who had high GADA titers. Differences in the clinical classification of diabetes are associated with graded differences in adaptive and innate immune reactivity.

OBJECTIVE Inflammatory processes contribute to both diabetes and cardiovascular risk. We wanted to investigate whether circulating concentrations of proinflammatory immune mediators and adiponectin in diabetic patients are associated with incident cardiovascular events. RESEARCH DESIGN AND METHODS In 1,038 participants with diabetes of the population-based ESTHER study, of whom 326 showed signs of renal dysfunction, Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% CIs for the association of increasing concentrations of C-reactive protein (CRP), interleukin-6 (IL-6), IL-18, macrophage migration inhibitory factor (MIF), adiponectin, and leptin with cardiovascular events (myocardial infarction, stroke, or fatal cardiovascular event) during a follow-up period of 8 years. RESULTS During follow-up, 161 subjects with diabetes experienced a primary cardiovascular event. Proinflammatory markers were not associated with a higher risk for primary cardiovascular events in the total study population after adjustment for multiple confounders. However, IL-6 and MIF were associated with cardiovascular events in subjects with renal dysfunction (HR for the comparison of top vs. bottom tertile 1.98 [95% CI 1.12–3.52], P [trend] = 0.10 for IL-6; 1.48 [0.87–2.51], P [trend] = 0.04 for MIF). Adiponectin levels were associated with cardiovascular events in the total population (1.48 [1.01–2.21], P [trend] = 0.03), and the association was even more pronounced in the subgroup with renal dysfunction (1.97 [1.08–3.57], P [trend] = 0.02). CONCLUSIONS In particular, the absence of an association between CRP and a U-shaped association of adiponectin levels with incident cardiovascular events show that associations between circulating immune mediators and cardiovascular risk differ between diabetic patients and subjects of the general population.

OBJECTIVE Specific autoantibodies characterize type 1 diabetes in childhood but are also found in adult-onset diabetes, even when initially non–insulin requiring, e.g., with latent autoimmune diabetes (LADA). We aimed to characterize adult-onset autoimmune diabetes. RESEARCH DESIGN AND METHODS We consecutively studied 6,156 European diabetic patients attending clinics within 5 years of diagnosis (age range, 30–70 years) examined cross-sectionally clinically and for GAD antibodies (GADA) and antibodies to insulinoma-associated antigen-2 (IA-2A) and zinc-transporter 8 (ZnT8A). RESULTS Of 6,156 patients, 541 (8.8%) had GADA and only 57 (0.9%) IA-2A or ZnT8A alone. More autoantibody-positive than autoantibody-negative patients were younger, leaner, on insulin (49.5 vs. 13.2%), and female (P < 0.0001 for each), though LADA patients (9.7% of total) did not show categorically distinct clinical features from autoantibody-negative type 2 diabetes. Similarly, more GADA patients with high (>200 World Health Organization IU) (n = 403) compared with low (n = 138) titer were female, lean, and insulin treated (54.6 vs. 39.7%) (P < 0.02 for each). Autoantibody-positive patients usually had GADA (541 of 598; 90.5%) and had LADA more often than type 1 autoimmune diabetes (odds ratio 3.3). CONCLUSIONS Adult-onset autoimmune diabetes emerges as a prevalent form of autoimmune diabetes. Our results indicate that adult-onset autoimmune diabetes in Europe encompasses type 1 diabetes and LADA in the same broad clinical and autoantibody-positive spectrum. At diagnosis, patients with adult-onset autoimmune diabetes are usually non–insulin requiring and clinically indistinguishable from patients with type 2 diabetes, though they tend to be younger and leaner. Only with screening for autoantibodies, especially GADA, can they be identified with certainty.

Background We investigated the adipokines adiponectin, leptin and resistin as serum biomarkers of beta-cell function in patients with type 1 diabetes. Methods One hundred and eighteen patients with ...

Type 1 diabetes and latent autoimmune diabetes in adults (LADA) are thought to result from immune-mediated β-cell destruction. It remains unclear why LADA is clinically less severe compared to type 1 diabetes. This study aimed to compare the pro-inflammatory (interferon-γ, IFN-γ) and anti-inflammatory (interleukin-13, IL-13) T-cell responses in humans with LADA and type 1 diabetes.IFN-γ and IL-13 T-cell responses to a panel of 16 (auto)-antigens were tested using an enzyme linked immune-spot technique and peripheral T-cells from 35 patients with type 1 diabetes, 59 patients with type 2 diabetes, 23 LADA patients, and 42 control subjects.LADA and type 1 diabetes patients did not display any statistically significant differences in the frequency of IFN-γ or IL-13 responses to auto-antigenic stimuli, positive control or mitogen. Overall very low T cell reactivity to autoantigens was detected in all groups. IL-13 responses but not IFN-γ responses to recall antigen tetanus toxoid were higher in healthy control subjects compared to patients with type 1 or type 2 diabetes or LADA (P0.05). Diabetes, independent of type, was associated with weaker response to recall antigen tetanus toxoid.LADA patients are indistinguishable from type 1 diabetes patients for cellular IFN-γ and IL-13 responses upon mitogen and recall antigen stimulation. These results extend previous findings showing that systemic cytokine/chemokine and humoral responses in type 1 diabetes and LADA are similar.

Diabet. Med. 29, 470–478 (2012) Abstract Aims Systemic concentrations of adhesion molecules and chemokines are associated with increased risk of cardiovascular complications. We compared these factors between patients with Type 2 diabetes vs. Type 1 diabetes or latent autoimmune diabetes in adults. Methods Serum concentrations of adhesion molecules sE-selectin, sICAM-1 and sVCAM-1, and chemokines CCL2, CCL3 and CCL4 were measured in 61 patients with latent autoimmune diabetes in adults, 90 with Type 1 diabetes, 465 with Type 2 diabetes and in 41 control subjects, using multiple regression models to adjust for possible confounders. Results Patients with Type 2 diabetes exhibited greater concentrations of adhesion molecules (P

Hintergrund und Fragestellung: Durch gesunde Ernahrung und Bewegung kann bei Typ-2-Diabetes die Stoffwechseleinstellung verbessert werden. Ohne externe Hilfe sind Lebensstilanderungen fur Betroffene meist schwer umzusetzen, da fur nachhaltigen Erfolg eine Anderung der inneren Einstellung notwendig ist. Daher wurde das computerbasierte medizinisch-mentale Motivationstraining Da Vinci zur Anderung von mentalen Einstellungen und Uberzeugungen entwickelt. Patienten und Methodik: Typ-2-Diabetes-Patienten wurden in 4 Trainingseinheiten in 10 Zentren von Mentaltrainern betreut. Mittels eines interaktiven Computerprogramms wurden Motivationshemmnisse identifiziert und uberwunden. Glukometabolische Parameter wurden zu Beginn, nach 3 Monaten Training sowie 3 und 6 Monate nach Trainingsende erfasst. Ergebnisse: Alle Teilnehmer (n = 61) entwickelten eine positive Einstellung zu ihren Handlungsmoglichkeiten und anderten eigenstandig ihren Lebensstil. Nach 3 Monaten Training kam es zu einer mittleren Reduktion von Gewicht (-4,6 kg; p Folgerung: Im Rahmen des medizinisch-mentalen Motivationstrainings, das keine diabetologischen Schulungsinhalte, sondern nur eine Anderung mentaler Einstellungen und Uberzeugungen vermittelt, gelang es den Teilnehmern, ihr vaskulares Risikoprofil signifikant zu verbessern. Dies weist auf eine nachhaltige Lebensstilanderung hin, da die erzielten Erfolge auch langerfristig aufrechterhalten werden konnen.

The ROSSO study is a retrospective, longitudinal cohort study performed to obtain epidemiological data on self-monitoring of blood glucose (SMBG) in patients with type 2 diabetes and to investigate the impact of SMBG on disease-related morbidity and mortality. 3,268 patients from 192 doctor's practices in Germany were included and their data from diabetes diagnosis (between 1995 and end of 1999) till drop-out (120 died, 17 drop-outs) or end of 2003 were collected from the medical records. The mean observational time was 6.5 years; total patient years of follow-up were 21.266 years. Based on these population data, questions about the motivation of patients with type 2 diabetes to start with SMBG, the changes in diabetes therapy and blood glucose associated with SMBG and the relationship of SMBG with non-fatal or fatal events during follow-up were evaluated. Use of SMBG is significantly associated with personal and baseline conditions. Patients using SMBG are more frequently treated by an internist, more often male, have more frequently a private health insurance, exhibit less frequently arterial hypertension, are younger, have lower systolic blood pressure and higher values of fasting blood glucose (FBG), HbA1c and triglycerides at diagnosis. The start of SMBG is preceded by a steady increase in blood glucose levels. It is accompanied by an intensification of diabetes therapy and followed by a significant reduction of blood glucose in the year after start of SMBG. 67% of the patients treated with diet only before SMBG began with antidiabetic medication concomitantly with SMBG (48% with oral antidiabetic agents (OAD), 9% with insulin and 10% with OAD and insulin) and 30% of the patients treated with OAD started on additional insulin treatment in parallel with SMBG. Switching from no antidiabetic medication to OAD reduced the mean FBG levels significantly from 9.31 to 8.70 mmol/l, from no medication to insulin from 10.05 to 6.93 mmol/l and from no medication to OAD and insulin from 10.85 to 8.92 mmol/l. Similar reductions of mean FBG levels were observed for switching from OAD to insulin therapy. Patients who stayed on OAD therapy also showed a significant reduction of FBG concentrations after the start of SMBG. The hazard for non-fatal events (particularly myocardial infarction and stroke) or overall mortality was significantly reduced for patients who performed SMBG during follow-up (p

This study was done to determine the effects of the angioprotective agent dobesilate on expression and activity on the constitutive nitric oxide synthase (ecNOS) in resident endothelial cells, as well as of the inducible nitric oxide synthase (iNOS) in cytokine-activated endothelial cells, by recording, in culture supernatants, the concentrations of citrulline as a reaction product of both enzymes. In capillary, microvascular, and macrovascular endothelial cells, Mg dobesilate incubation (0.25-1 mM) for 24 hours led to a highly significant concentration-correlating increase in ecNOS activities. These increases were not due to iNOS expression, and with cytokine-activated endothelial cell cultures that do express iNOS only moderate effects with little or no concentration dependency were seen. Addition of the NOS inhibitor NG-monomethyl-L-arginine (NMA) significantly suppresses citrulline formation in all cultures as evidence for the enzyme specificity.

One of the main challenges in caffeine research is a real understanding of the mechanism of action behind the psychostimulant effects of caffeine. Caffeine is a non-selective adenosine receptor antagonist, and for about three decades, it has been established that, in the brain, caffeine targets mainly adenosine A1 and A2A receptors. The same as classical psychostimulants, caffeine produces motor-activating, reinforcing, and arousing effects. The psychostimulant effects of caffeine seem to depend on its ability to counteract multiple effects of adenosine in the central ascending neurotransmitter systems.Motor and reinforcing effects seem to depend mostly on the ability of caffeine to release preand postsynaptic brakes that adenosine imposes on the ascending dopaminergic system. Arousing effects of caffeine seem to depend on the blockade of multiple inhibitory mechanisms that adenosine, as an endogenous sleep-promoting substance, exerts on the multiply interconnected ascending arousal systems. Those mechanisms include a direct A1 receptor-mediated modulation of the corticopetal basal forebrain system and an indirect A2A receptor-mediated modulation of the hypothalamic histaminergic and orexinergic systems. We are therefore starting to understand the mechanisms responsible for at least the acute psychostimulant effects of caffeine. However, we know very little about some intriguing temporal properties of the psycostimulant effects of caffeine, such as the well-known fast development of tolerance upon repeated exposure. We also understand very little about the mechanisms behind the use of caffeine combined with other psychostimulants and the recent growing consumption of combined alcoholand caffeine-containing drinks. In addition to pharmacokinetic mechanisms, we need to establish which pharmacodynamic changes, such as modifications in the expression and function of adenosine receptors, develop after combined or chronic caffeine consumption. The study of the mechanisms behind the motor-activating properties of caffeine led to the discovery of adenosine receptor heteromers. Although initially considered as just a provider of tight receptor interactions, receptor heteromer has been recently defined as ‘‘a macromolecular complex composed of at least two (functional) receptor units with biochemical properties that are demonstrably different from those of its individual components.’’ This conceptual switch implies that adenosine receptor heteromers should be considered as the real targets of caffeine. So far, those include adenosine-dopamine, adenosine-cannabinoid, and adenosineglutamate receptor heteromers. Very likely, the study of the biochemical characteristics of the adenosine receptor heteromers and their specific neuronal expression during caffeine exposure will advance our understanding about the intriguing pharmacological properties of caffeine.

Objective The aim of the current study was to investigate whether autoantigen directed T-cell reactivity relates to β-cell function during the first 78 weeks after diagnosis of type 1 diabetes. Research design and methods 50 adults and 49 children (mean age 27.3 and 10.9 years respectively) with recent onset type 1 diabetes who participated in a placebo-controlled trial of immune intervention with DiaPep277 were analyzed. Secretion of interferon (IFN)-γ, interleukin (IL)-5, IL-13 and IL-10 by single peripheral mononuclear cells (PBMC) upon stimulation with islet antigens GAD65, heat shock protein 60 (Hsp60) protein-tyrosine-phosphatase-like-antigen (pIA2) or tetanus toxoid (TT) was determined applying ELISPOT; β-cell function was evaluated by glucagon stimulated C-peptide. Multivariate regression analysis was applied. Results In general, number of islet antigen-reactive cells decreased over 78 weeks in both adults and children, whereas reactivity to TT was not reduced. In addition, there was an association between the quality of immune cell responses and β-cell function. Overall, increased responses by IFN-γ secreting cells were associated with lower β-cell function whereas IL-5, IL-13 and IL-10 cytokine responses were positively associated with β-cell function in adults and children. Essentially, the same results were obtained with three different models of regression analysis. Conclusions The number of detectable islet-reactive immune cells decreases within 1–2 years after diagnosis of type 1 diabetes. Cytokine production by antigen-specific PBMC reactivity is related to β-cell function as measured by stimulated C-peptide. Cellular immunity appears to regress soon after disease diagnosis and begin of insulin therapy.

Background: In the German multicenter, retrospective cohort study (ROSSO), those patients with type 2 diabetes who performed self-monitoring of blood glucose (SMBG) had a better long-term clinical outcome. We analyzed whether confounders accounted for the lower rate of clinical events in the SMBG cohort. Methods: ROSSO followed 3268 persons from diagnosis of type 2 diabetes for a mean of 6.5 years. Data were retrieved from patient files of randomly contacted primary care practices. Results: In total, more than 60 potential confounders were documented, including nondisease-associated parameters such as patient's health insurance, marital status, habitation, and characteristics of diabetes centers. There were only modest differences for these parameters between groups with versus without SMBG, and multiple adjustments did not weaken the association of SMBG use with better outcome (odds ratio 0.65, 95% confidence interval 0.53–0.81, p < .001). This was also true for subgroups of patients defined by type of antidiabetes treatment. Propensity score analysis confirmed the association of SMBG use with outcome. Using key baseline parameters, 813 matching pairs of patients were identified. The analysis again showed a better long-term outcome in the SMBG group (hazard ratio 0.67 p = .004). Conclusion: An influence of nonrecognized confounders on better outcome in the SMBG group is rendered improbable by similar results obtained with adjustments for disease-associated or disease-independent parameters, by the analysis of patient subgroups, by propensity score analysis and by performing a matched-pair analysis. The higher flexibility in pharmacological antidiabetes treatment regimens in the SMBG cohort suggests a different attitude of treating physicians and patients in association with SMBG.

Subtotal pancreatectomy (90%) in Lewis rats induces chronic islet inflammation and tissue damage in the remaining pancreas 4 months after surgery. Concomitantly, significant enlargement of the islets of Langerhans was observed (90% pancreatectomy: islet/pancreas area: 25.6 +/- 9.6 x 10(-3), beta-cell/pancreas area: 12.4 +/- 4.4 x 10(-3); n = 4; controls without pancreatectomy: islet/pancreas area: 5.5 +/- 1.7 x 10(-3), beta-cell/pancreas area: 4.6 +/- 1.5 x 10(-3); n = 4; p < 0.05, respectively). Islet growth is mainly due to an increase in beta-cell mass. Beta-cell regeneration was not caused by the surgical manipulations or by metabolic stress. The former was ruled out by performing 10% pancreatectomy which did not cause islet enlargement after 4 months (islet/pancreas area: 13.6 +/- 11.3 x 10(-3), beta-cell/pancreas area: 7.1 +/- 2.0 x 10(-3); n = 3). An influence of metabolic stress was excluded by continuous substitution of syngenic islet antigens, which inhibits insulitis. In the absence of islet inflammation, despite persistent metabolic stress, beta-cell regeneration did not occur (islet/pancreas area: 7.0 +/- 5.5 x 10(-3), beta-cell/pancreas area: 5.5 +/- 4.1 x 10(-3); n = 4). Continuous treatment of animals after 90% pancreatectomy by insulin implants (1.5 U/day) avoided insulitis and beta-cell growth (islet/pancreas area: 9.2 +/- 1.1 x 10(-3), beta-cell/pancreas area: 6.8 +/- 1.0 x 10(-3), n = 3): All enlarged islets observed 4 months after 90% pancreatectomy without further treatment were infiltrated. Thus, beta-cell growth appears to be a response to insulitis. The stimulus for beta-cell growth could result from tissue damage caused by infiltrating cells or from cytokines secreted by the infiltrating cells, or both.

Experiments with animal models have proven that intervention protocols avoiding immunosuppressants can effectively prevent immune-mediated diabetes. These new approaches aim at either supporting the defence of islet cells against inflammatory attack or at modulating the type of the immune response to beta cells towards a more benign quality. Another approach is to reduce the exposure to putative diabetogenic dietary factors during infancy. All of the three strategies are presently tried in clinical studies.

A key characteristic of human autoimmune disease is the focus on a few target autoantigens. This phylogenetically conserved antigenic restriction is consistent with the concept that the non adaptive innate immune system is critical to disease development. Indeed, defects of macrophages, dendritic cells or NK T cells have been reported for type I diabetes or its animal models. Products of the innate immune system, such as IL-12, IL-15 and IL-18 have been shown to drive destructive insulitis. Besides the modulatory impact of infections a key environmental factor appears to be the diet. Wheat, soy and cow milk may contain diabetogenic proteins, as judged from animal experiments. These findings indicate a key role of the gut immune system which probably exhibits deficient oral tolerance mechanisms and therefore would mount a proinflammatory response when challenged with putative diabetogenic compounds in the diet. Dietary intervention studies to modulate the natural coursc of type I diabetes are underway.

The natural course of macrovascular events in patients with type 2 diabetes was analyzed: what are the risk factors, and what is the relationship to the use of self-monitoring of blood glucose (SMBG)?Data were retrieved from ROSSO-a German retrospective observational study-which followed 3,268 patients from diagnosis of type 2 diabetes for 6.5 +/- 1.6 years. We compared patients with or without a nonfatal macrovascular event (myocardial infarction or stroke) and patients using or not using SMBG.At baseline, worse glycemic control and higher body mass index were not risk factors for macrovascular events. Moreover, there was no association with classic risk factors like blood pressure or total cholesterol. Overall, there was a higher incidence of stroke than of myocardial infarction (0.78% vs. 0.51%). Myocardial infarction was positively associated with male sex, and stroke with age (P0.001 for each). Patients using SMBG compared to patients not using SMBG had fewer myocardial infarctions (2.0% vs. 4.0%, P = 0.002) and strokes (3.6% vs. 5.7%, P = 0.005), experienced a stroke later after diagnosis of type 2 diabetes (5.1 +/- 1.9 vs. 3.8 +/- 2.1 years, P0.001), and had a higher mean hemoglobin A1c in the years before a myocardial infarction (7.8 +/- 1.8% vs. 6.8 +/- 1.1%, P = 0.003) or a stroke (8.0 +/- 1.8% vs. 7.1 +/- 1.2%, P = 0.003). However, classic cardiovascular risk factors did not differ between patients using or not using SMBG.In patients with type 2 diabetes SMBG was associated with a lower event rate of myocardial infarction (-50%) and stroke (-37%), although at baseline the classic risk factors for macrovascular events were not different in both groups.

Obesity and related disorders represent states of systemic low-grade inflammation. Chemokine secretion by adipocytes may initiate leukocyte infiltration in obese adipose tissue and thus mediate an important step in the establishment of chronic immune activation. The chemokine RANTES (regulated upon activation normal T cell expressed and secreted)/CCL5 is a chemoattractant for various leukocyte subsets. This study was designed to examine whether RANTES is expressed and released by human adipocytes and how its expression is regulated. RANTES expression under basal conditions was studied in mature adipocytes. Cells were therefore challenged with lipopolysaccharide (LPS), interferon (IFN)-gamma, interleukin (IL)-4, monocyte chemoattractant protein (MCP)-1 or exposed to low oxygen pressure. RANTES was expressed and secreted constitutively in most samples of mature adipocytes from the omental and the subcutaneous depot. RANTES release was dependent on adipocyte size and also seemed to be higher from cells of obese donors. Hypoxia (4% O (2)) caused an approximately 36% increase of RANTES release. Human adipocytes express the chemokine RANTES and are thus identified as a novel cellular source of this immune mediator. LPS and IFNgamma do not seem to play a significant role for the expression of RANTES in contrast to moderate hypoxia, which points to a distinct role in the innate immune system.

BACKGROUND AND OBJECTIVE Worldwide the quality of care of patients with type 2 diabetes has been investigated only by analysing within cross-sectional studies. But the quality of care in relation to statutory or private health plans in not known. It was the aim of this study to ascertain retrospectively, how in the course of time from first diagnosis the quality of medical care of patients with type 2 diabetes differed depending on the type of health insurance of the individual patient. METHODS AND PATIENTS As part of the ROSSO study (a German retrospective epidemiological cohort study), data on all patients diagnosed with type 2 diabetes between 1.1.1995 and 31.12.1999 had been recorded. They had been collected from 192 randomly selected general practitioner or internal medicine specialist practices. RESULTS The data of 3268 patients diagnosed with type 2 diabetes were recorded. The mean observation period was 6.5 years. The mean age of this patients at the time of diagnosis of diabetes was 62.4 +/- 9.6 years, 49 % being male. The portion of patients visiting their chosen practice at least 3 - 4 times in a given year was about 70 - 80 %. Documentation of HbA (1c) or blood pressure as requested in the guideline was presented in 20 - 50 % of patient files with no differences between enrolled in a statutory or private health plans. Even when cholesterol or blood pressure levels were greatly elevated 20 - 50 % of patients had been prescribed no adequate drug treatment. Only 20 % of the patients had been described platelet aggregation inhibitors during the first years after myocardial infarction or stroke. CONCLUSION The quality of care in general practitioner of specialist internal medicine practices failed to meet the guidelines for patients with type 2 diabetes. There were no differences that depended on whether the patients had been enrolled in a statutory or private health plan.

The effect of passive insulin antibody transfer into recipient mice was reevaluated. Mice of inbred strains BALB/c, C57Bl/6 and DBA/2 received 10 injections of hyperimmune guinea pig insulin antiserum within 2 weeks. Ten days later the animals were sacrificed. It was found that up to 40% of animals had developed chronic lymphocytic infiltrations of pancreatic islets (insulitis) without showing diabetic symptoms. It is concluded that repeated damaging of islet tissue by passive insulin antibody transfer may result in chronic, possibly autoimmune insulitis. Our observation supports the concept that partial damage of pancreatic islets by environmental factors may trigger an organ-specific progressive islet cell destruction process mediated by immune cells.

OBJECTIVE—β-Cell function in type 1 diabetes clinical trials is commonly measured by C-peptide response to a secretagogue in either a mixed-meal tolerance test (MMTT) or a glucagon stimulation test (GST). The Type 1 Diabetes TrialNet Research Group and the European C-peptide Trial (ECPT) Study Group conducted parallel randomized studies to compare the sensitivity, reproducibility, and tolerability of these procedures. RESEARCH DESIGN AND METHODS—In randomized sequences, 148 TrialNet subjects completed 549 tests with up to 2 MMTT and 2 GST tests on separate days, and 118 ECPT subjects completed 348 tests (up to 3 each) with either two MMTTs or two GSTs. RESULTS—Among individuals with up to 4 years’ duration of type 1 diabetes, >85% had measurable stimulated C-peptide values. The MMTT stimulus produced significantly higher concentrations of C-peptide than the GST. Whereas both tests were highly reproducible, the MMTT was significantly more so (R2 = 0.96 for peak C-peptide response). Overall, the majority of subjects preferred the MMTT, and there were few adverse events. Some older subjects preferred the shorter duration of the GST. Nausea was reported in the majority of GST studies, particularly in the young age-group. CONCLUSIONS—The MMTT is preferred for the assessment of β-cell function in therapeutic trials in type 1 diabetes.

OBJECTIVE—Although sex differences have been reported for associations between obesity and inflammation, the question of whether there is an effect modification by sex in the association between inflammation and type 2 diabetes has not been investigated in detail. Therefore, the aim of this study was to compare associations of markers of inflammation with type 2 diabetes risk between men and women. RESEARCH DESIGN AND METHODS—Following a case-cohort design, cases of incident type 2 diabetes were identified from 7,936 subjects aged 35–74 years at baseline who participated in the population-based Monitoring of Trends and Determinants in Cardiovascular Disease (MONICA)/Cooperative Research in the Region of Augsburg (KORA) studies conducted between 1984 and 2002. Concentrations of C-reactive protein (CRP) and interleukin (IL)-6 were measured in 527 cases of incident type 2 diabetes (305 men and 222 women) and 1,698 noncases (889 men and 809 women). RESULTS—After adjustment for age and survey and lifestyle factors including smoking, alcohol intake, and physical activity, elevated concentrations of CRP showed a considerably stronger association with risk of type 2 diabetes in women (hazard ratio comparing tertile extremes 7.60 [95% CI 4.43–13.04]) than in men (1.84 [1.27–2.67]). The P value for the sex interaction was CONCLUSIONS—Our data suggest that inflammatory processes may be of particular importance in the pathogenesis of type 2 diabetes in women.

Definitions of the metabolic syndrome (MetS) include obesity, dyslipidemia, elevated levels of fasting blood glucose, and blood pressure as criteria, but it is also known that the MetS is associated with chronic, subclinical inflammation. Hyperglycemia (fasting and postprandial) may be important in exacerbating this proinflammatory state. We aimed to assess the impact of oral glucose challenge and in vitro glucose-stimulation on gene expression and secretion of inflammatory parameters in peripheral blood leukocytes and to investigate whether presence of the MetS could "prime" leukocytes to up-regulate proinflammatory markers in response to glucose. Using quantitative real-time PCR, we could show that the expression of intercellular adhesion molecule 1 (ICAM-1), tumor necrosis factor alpha (TNF-alpha), and interleukin 6 (IL-6) significantly increased in peripheral blood leukocytes from "MetS" subjects (n=39) compared to "no MetS" subjects (n=35) 2 h after an oral glucose tolerance test (ICAM-1 +52%, TNF-alpha +107%, and IL-6 +38%) and also in vitro after 72 h cultivation in high-glucose medium (ICAM-1 +74%, TNF-alpha +71%, and IL-6 +44%). Using ELISA and Luminex technique, we further observed a trend towards increased immune mediator concentrations in the corresponding cell culture supernatants from MetS patients (ICAM-1 +21%, TNF-alpha +31%, and IL-6 +175%). Thus, the MetS may support peripheral inflammation by sensitizing leukocytes to up-regulate proinflammatory markers in response to glucose, which in turn increases the risk for type-2 diabetes mellitus and cardiovascular disease.