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Background: Hyperglycaemia is frequent in acute ischemic stroke and denotes a bad prognosis, even in the absence of pre-existing diabetes. However, in clinical trials treatment of elevated glucose levels with insulin did not improve stroke outcome, suggesting that collateral effects rather than hyperglycaemia itself aggravate ischemic brain damage. As reactive glucose metabolites, glyoxal and methylglyoxal are candidates for mediating the deleterious effects of hyperglycaemia in acute stroke., Methods: In 135 patients with acute stroke, we used liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) to measure glyoxal, methylglyoxal and several of their glycated amino acid derivatives in serum. Results were verified in a second cohort of 61 stroke patients. The association of serum concentrations with standard stroke outcome scales (NIHSS, mRS) was tested., Results: Glucose, glyoxal, methylglyoxal, and the glyoxal-derived glycated amino acid N δ -(5-hydro-4-imidazolon-2-yl)ornithine (G-H1) were positively correlated with a bad stroke outcome at 3 months as measured by mRS90, at least in one of the two cohorts. However, the glycated amino acids N ε -carboxyethyllysine (CEL) and in one cohort pyrraline showed an inverse correlation with stroke outcome probably reflecting lower food intake in severe stroke. Patients with a poor outcome had higher serum concentrations of glyoxal and methylglyoxal., Conclusions: The glucose-derived α-dicarbonyl glyoxal and glycated amino acids arising from a reaction with glyoxal are associated with a poor outcome in ischemic stroke. Thus, lowering α-dicarbonyls or counteracting their action could be a therapeutic strategy for hyperglycaemic stroke., (© 2023. The Author(s).)

Background: Higher dietary intake of fibers and coffee, but lower red meat intake is associated with reduced risk for type 2 diabetes in epidemiological studies. We hypothesized that a calorie-restricted diet, which is high in fiber and coffee, but free of red meat, improves beta-cell function in patients with T2D., Methods: In a randomized parallel-group pilot trial, obese type 2 diabetes patients were randomly allocated to consume either a diet high in cereal fiber and coffee, but free of red meat ( n  = 17) (L-RISK) or a diet low in fiber, free of coffee but high in red meat ( n  = 20) (H-RISK) for 8 weeks. Insulin secretion was assessed from glucagon stimulation tests (GST) and mixed-meal tolerance tests (MMTT) before and after dietary intervention., Results: Both diets resulted in comparable reduction of fasting concentrations of insulin (H-RISK -28% vs. L-RISK -32%, both p  < 0.01), C-peptide (H-RISK -26% vs. L-RISK -30%, both p  < 0.01) and blood glucose (H-RISK -6.8%, p  < 0.05 vs. L-RISK -10%, p  < 0.01). Gastric inhibitory peptide (GIP) secretion increased by 24% after 8 weeks in the L-RISK only ( p  < 0.01). However, GST and MMTT showed no differences in insulin secretion after intervention., Conclusions: Calorie restriction independent of the intake of fiber, coffee or meat failed to improve beta-cell function, but improved GIP secretion in obese patients with type 2 diabetes., Trial Registration: Registration at Clinicaltrials.gov, Identifier number: NCT01409330, Registered 4 August 2011 - Retrospectively registered., Competing Interests: The study was performed according to the Declaration of Helsinki, approved by the ethics committee of the Medical Faculty of Heinrich Heine University Düsseldorf. All participants gave written informed consent before inclusion in the study.All authors have seen and approved the manuscript being submitted.The authors declare that they have no competing interests.Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Background: The aim of this study was to investigate the effect of a lifestyle intervention in obesity on the soluble form of the activated leukocyte cell adhesion molecule (sALCAM) and its association with metabolic parameters., Methods: Twenty-nine obese subjects selected from the OPTIFAST®52 program. This program consisted into 2 crucial phases: an initial 12-week active weight reduction phase, followed by a 40-week weight maintenance phase. At baseline, after 12 weeks and at the end of the program, fasting glucose and insulin, total cholesterol, LDL-C, HDL-C, triglycerides, adiponectin, leptin, high sensitivity CRP, sALCAM, homeostasis model assessment-estimated insulin resistance (HOMA-IR) and leptin-to-adiponectin-ratio were determined. Oral glucose tolerance test (OGTT) was performed when indicated., Results: At baseline, the serum concentration of sALCAM was increased and correlated positively with HOMA-IR and negatively with age. At the end of the program, sALCAM concentrations decreased significantly. Multivariate analysis showed that sALCAM significantly correlated with age, glucose concentration after 2 h OGTT and the HOMA-IR. A higher decrease of HOMA-IR during the study was observed in subjects with higher concentration of sALCAM at baseline., Conclusions: sALCAM might be a novel biomarker in obesity that correlates and predicts insulin sensitivity improvement and that can be affected by lifestyle intervention.

Background: Endothelial progenitor cells (EPC) are bone marrow-derived cells which can undergo differentiation into endothelial cells and participate in endothelial repair and angiogenesis. Insulin facilitates this in vitro mediated by the IGF-1 receptor. Clinical trials showed that the number of circulating EPCs is influenced by glucose control and EPC are a predictor of cardiovascular death. To study direct effects of insulin treatment on EPCs in type 2 diabetes patients, add-on basal insulin treatment was compared to an escalation of oral medication aiming at similar glucose control between the groups., Methods: 55 patients with type 2 diabetes (61.6±5.9 years) on oral diabetes medication were randomized in a 2:2:1 ratio in 3 groups. Patients were treated additionally with insulin glargine (n=20), NPH insulin (n=22) or escalated with oral medication (n=13). Number of circulating EPC, EPC-outgrowth, intima media thickness, skin microvascular function and HbA1c were documented at baseline and/or after 4 weeks and 4 months., Results: HbA1c at baseline was, 7.3+/-0.7% in the oral group, 7.3+/-0.9% and 7.5+/-0.7% in the glargine and NPH insulin respectively (p=0.713). HbA1c after 4 months decreased to 6.8+/-0.8%, 6.6+/-0.7% and 6.7+/-0.6%, in the oral, glargine and NPH insulin group respectively (p=0.61). FACS analysis showed no difference in number of circulating EPC between the groups after 4 weeks and 4 months. However, the outgrowth of EPCs as detected by colony forming assay was increased in the NPH insulin and glargine groups (29.2+/-6.4 and 29.4+/- 6.7 units respectively) compared to the group on oral medication (23.2+/-6.3, p=0.013) after 4 months of treatment. A significant decrease of IMT from 0.80mm (+/-0.14) at baseline to 0.76mm (+/-0.12) after 4 months could be observed in all patients only (p=0.03) with a trend towards a reduction of IMT after 4 months when all patients on insulin treatment were compared to the oral treatment group (p=0.06). Skin microvascular function revealed no differences between the groups (p=0.74)., Conclusion: The study shows that a 4-month treatment with add-on insulin significantly increases the outgrowth of EPC in patients with type 2 diabetes mellitus., Trial Registration: (Clinical Trials Identifier: NCT00523393).

The serotonergic pathway plays a major role in the development of obesity. Its activity can be modulated by the 5-HT transporter-linked polymorphic region in the SLC6A4 gene and the upstream variable number of tandem repeats polymorphism in the MAOA gene. We studied whether these genetic modulations have an influence on weight reduction and weight maintenance in a one-year weight reduction program (OPTIFAST ® 52). The polymorphisms were genotyped by PCR in a sample of 135 female and 67 male subjects with severe obesity (44 ± 13 years, 122.3 ± 22.2 kg, BMI: 41.7 ± 6.7 kg/m 2 ). The program leads to a total weight loss of 19.9 ± 9.8 kg (16.9 ± 8.3 %) in women and 27.4 ± 13.6 kg (20.4 ± 9.9 %) in men. Anthropometric measurements and blood levels were determined at the start of the program (T0), after the weight reduction phase (T1) and after the subsequent weight maintenance phase at the end of the program (T2). Each polymorphism alone did not significantly influence weight loss or weight maintenance neither in men nor in women. However, women carrying both risk genotypes (SS and 3/3) displayed a lower total weight loss during the program (p = 0.05). This effect derived mainly from difficulties in the weight maintenance phase (p = 0.11), while the weight reduction phase was not affected (p = 0.61). No influence was found in men (p = 0.93). Modulation of the serotonergic pathway by carrying both risk alleles seems to influence success of weight loss programs in women with severe obesity due to problems in stabilizing body weight after weight reduction.

Background: Type 2 diabetes mellitus (T2DM) is a disease with high prevalence, associated with severe co-morbidities as well as being a huge burden on public health. It is known that glycemic control decreases long-term morbidity and mortality. The current standard therapy for T2DM is medical treatment. Several randomized controlled trials (RCTs) performed in obese patients showed remission of T2DM after bariatric surgery. Recent RCTs have shown bariatric procedures to produce a similar effect in non-morbidly and non-severely obese, insulin-dependent T2DM patients suggesting procedures currently used in bariatric surgery as new therapeutical approach in patients with T2DM. This study aims at investigating whether Roux-en-Y gastric bypass (RYGB) is an efficient treatment for non-severely obese T2DM patients in terms of preventing long-term complications and mortality., Methods: The DiaSurg 2 trial is a multicenter, open randomized controlled trial comparing RYGB including standardized medical treatment if needed to exclusive standardized medical treatment of T2DM (control group). The primary endpoint is a composite time-to-event endpoint (cardiovascular death, myocardial infarction, coronary bypass, percutaneous coronary intervention, non-fatal stroke, amputation, surgery for peripheral atherosclerotic artery disease), with a follow-up period of 8 years. Insulin-dependent T2DM patients aged between 30 and 65 years will be included and randomly assigned to one of the two groups. The experimental group will receive RYGB and, if needed, standardized medical care, whereas the control group will receive exclusive standardized medical care, both according to the national treatment guidelines for T2DM. Statistical analysis is based on Cox proportional hazards regression for the intention-to-treat population. Assuming a loss to follow-up rate of 20%, 200 patients will be randomly allocated to the comparison groups. A total sample size of n=400 is sufficient to ensure 80% power in a two-tailed significance test at alpha=5%., Discussion: The DiaSurg2 trial will yield long-term data (8 years) on diabetes-associated morbidity and mortality in patients with insulin-dependent T2DM receiving either RYGB or standardized medical care., Trial Registration: The trial protocol has been registered in the German Clinical Trials Register DRKS00004550.

Background: Calcium phosphate cements are used frequently in orthopedic and dental surgeries. Strontium-containing drugs serve as systemic osteoblast-activating medication in various clinical settings promoting mechanical stability of the osteoporotic bone., Methods: Strontium-containing calcium phosphate cement (SPC) and calcium phosphate cement (CPC) were compared regarding their local and systemic effects on bone tissue in a standard animal model for osteoporotic bone. A bone defect was created in the distal femoral metaphysis of 60 ovariectomized Sprague-Dawley rats. CPC and SPC were used to fill the defects in 30 rats in each group. Local effects were assessed by histomorphometry at the implant site. Systemic effects were assessed by bone mineral density (BMD) measurements at the contralateral femur and the spine., Results: Faster osseointegration and more new bone formation were found for SPC as compared to CPC implant sites. SPC implants exhibited more cracks than CPC implants, allowing more bone formation within the implant. Contralateral femur BMD and spine BMD did not differ significantly between the groups., Conclusions: The addition of strontium to calcium phosphate stimulates bone formation in and around the implant. Systemic release of strontium from the SPC implants did not lead to sufficiently high serum strontium levels to induce significant systemic effects on bone mass in this rat model.

Psychosocial stress has been shown to be a contributing factor in the development of atherosclerosis. Although the underlying mechanisms have not been elucidated entirely, it has been shown previously that the transcription factor nuclear factor-κB (NF-κB) is an important component of stress-activated signaling pathway. In this study, we aimed to decipher the mechanisms of stress-induced NF-κB-mediated gene expression, using an in vitro and in vivo model of psychosocial stress. Induction of stress led to NF-κB-dependent expression of proinflammatory (tissue factor, intracellular adhesive molecule 1 [ICAM-1]) and protective genes (manganese superoxide dismutase [MnSOD]) via p50, p65 or cRel. Selective inhibition of the different subunits and the respective kinases showed that inhibition of cRel leads to the reduction of atherosclerotic lesions in apolipoprotein(-/-) (ApoE(-/-)) mice via suppression of proinflammatory gene expression. This observation may therefore provide a possible explanation for ineffectiveness of antioxidant therapies and suggests that selective targeting of cRel activation may provide a novel approach for the treatment of stress-related inflammatory vascular disease.

Background: The receptor for advanced glycation endproducts, RAGE, is involved in the pathogenesis of many inflammatory conditions, which is mostly related to its strong activation of NF-κB but also due to its function as ligand for the β2-integrin Mac-1. To further dissect the stimulus-dependent role of RAGE on leukocyte recruitment during inflammation, we investigated β2-integrin-dependent leukocyte adhesion in RAGE-/- and Icam1-/- mice in different cremaster muscle models of inflammation using intravital microscopy., Results: We demonstrate that RAGE, but not ICAM-1 substantially contributes to N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced leukocyte adhesion in TNF-α-pretreated cremaster muscle venules in a Mac-1-dependent manner. In contrast, fMLP-stimulated leukocyte adhesion in unstimulated cremaster muscle venules is independent of RAGE, but dependent on ICAM-1 and its interaction with LFA-1. Furthermore, chemokine CXCL1-stimulated leukocyte adhesion in surgically prepared cremaster muscle venules was independent of RAGE but strongly dependent on ICAM-1 and LFA-1 suggesting a differential and stimulus-dependent regulation of leukocyte adhesion during inflammation in vivo., Conclusion: Our results demonstrate that RAGE and ICAM-1 differentially regulate leukocyte adhesion in vivo in a stimulus-dependent manner.

Background: Postoperative hyperthyroidism occurs in approximately one third of patients following parathyroidectomy due to primary hyperparathyroidism (PHP), but has only rarely been described in secondary hyperparathyroidism (SHP). The frequency, course, and laboratory markers of postoperative hyperthyroidism in SHP remain unknown. Our purpose was to evaluate the frequency and the clinical course of postoperative hyperthyroidism following surgery of SHP and to determine the diagnostic value of thyroglobulin in this setting., Material and Methods: A total of 40 patients undergoing parathyroidectomy because of SHP were included in this study. Thyroid stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4), and thyroglobulin (Tg) were determined one day before and on day 1, 3, 5, 10, and 40 after surgery. At each of these visits patients were clinically evaluated for signs or symptoms of hyperthyroidism., Results: Biochemical evidence of hyperthyroidism was evident in 77% of patients postoperatively despite of preoperatively normal serum levels. TSH dropped from 1.18 ± 0.06mU/L to 0.15 ± 0.07mU/L (p = 0.0015). Free triiodothyronine (fT3) and fT4 levels increased from 2.86 ± 0.02ng/L and 10.32 ± 0.13ng/L, respectively, to their maximum of 4.83 ± 0.17ng/L and 19.35 ± 0.58ng/L, respectively. Thyroglobulin levels rose from 3.8 ± 0.8ng/mL to 111.8 ± 45.3ng/mL (p<0.001). At day 40 all thyroid related laboratory values were within normal range. Correlation analysis of postoperative values revealed significant correlations for lowest TSH (r = -0.32; p = 0.038), and highest fT3 (r = 0.55; p<0.001) and fT4 levels (r = 0.67; p<0.001) with Tg., Conclusion: Transient hyperthyroidism is frequent after parathyroidectomy for SHP with Tg being a suitable marker. Awareness of this self-limiting disorder is important to avoid inappropriate and potentially harmful treatment.

Background: Ambigous results exist on fetuin-A as marker for vascular disease in type 2 diabetes. This study aims to define the role of fetuin-A as marker for micro- and macrovascular disease in a high risk population of patients with type 2 diabetes mellitus and early diabetic nephropathy., Methods: Fetuin-A serum levels were assessed by ELISA in a cross-sectional setting in 153 patients with type 2 diabetes. Associations of fetuin-A with metabolic, inflammatory and vascular markers were studied. Atherosclerotic burden was assessed by ankle-brachial-index (ABI) as well as detection of common carotid artery intima-media thickness (IMT)., Results: Levels of fetuin-A were lower in male than in female patients (0.49 ± 0.15 vs. 0.56 ± 0.20 g/L, p = 0.02). In addition, there was an inverse correlation with age (r = -0.20, P = 0.01). Bivariate correlations adjusted for age and gender revealed no significant correlations with metabolic parameters, except for a weak inverse correlation with serum adiponectin (r = -0.19, p = 0.02). Regarding parameters of micro- and macrovascular disease, fetuin-A was significantly associated with ABI (r = 0.18, p = 0.04), while there was no association with IMT (r = -0.07, p = n.s). Patients with an ABI < 0.9 had lower fetuin A levels than patients with an ABI 0.9-1.3 or > 1.3 (0.43 ± 0.10 vs. 0.52 ± 0.17 vs. 0.54 ± 0.18 g/L p = 0.05). Neither GFR nor albuminuria were associated with fetuin-A serum levels. Patients with prevalent neuropathy did not have altered fetuin-A levels compared to diabetic controls. In step-wise logistic regression analysis including age, gender, HbA1c, total cholesterol, glomerular filtration rate and fetuin-A, only total cholesterol (β = 0.01, p = 0.02) and fetuin-A (β = -5.99, p = 0.03) proved to be independent predictors of an ABI < 0.9., Conclusions: The results of this cross-sectional study suggest that lower fetuin-A levels are associated with macrovascular late complications in high-risk type 2 diabetes patients while there are no associations of fetuin-A with metabolic status or microvascular complications.

Endothelial progenitor cells (EPCs) have been shown to be involved in vascular regeneration and angiogenesis in experimental diabetes. Because insulin therapy mobilizes circulating progenitor cells, we studied the effects of insulin on outgrowth of EPCs from peripheral blood mononuclear cells of healthy volunteers and patients with type 2 diabetes. Insulin increased the formation of EPC colony-forming units in a dose-dependent manner, half-maximal at 1.5 nM and peaking at 15 nM. Inhibiting the insulin receptor with neutralizing antibodies or antisense oligonucleotides had no effect on EPC outgrowth.(1) In contrast, targeting the human insulin-like growth factor 1 (IGF-1) receptor with neutralizing antibodies significantly suppressed insulin-induced outgrowth of EPCs from both healthy controls and patients with type 2 diabetes. This IGF-1 receptor-mediated insulin effect on EPC growth was at least in part dependent on MAP kinases(2) and was abrogated when extracellular signal-regulated kinase 1/2 (Erk1/2) and protein kinase 38 (p38) activity was inhibited. To study the functional relevance of the observed insulin effects, we studied EPC-induced tube formation of bovine endothelial cells in vitro. Insulin-stimulated EPCs incorporated into the endothelial tubes and markedly enhanced tube formation. In conclusion, this is the first study showing an insulin-mediated activation of the IGF-1 receptor leading to an increased clonogenic and angiogenic potential of EPCs in vitro.

Background: Total circulating soluble receptor for advanced glycation endproducts (sRAGE) and a more defined endogenous secretory splice variant of the receptor (esRAGE) were shown to be associated with different markers of cardiovascular risk in patients with diabetes. Since previous data were partly divergent, the aim of this study was to compare sRAGE and esRAGE in a head-to-head analysis in patients with type 2 diabetes (T2DM) with albuminuria., Methods: sRAGE and esRAGE were studied in plasma of 110 T2DM patients using enzyme-linked immunosorbant assays (ELISA) detecting either sRAGE or esRAGE only. Both sRAGE and esRAGE were compared with regard to applicability as markers for vascular disease and glucose control in T2DM., Results: In bivariate analysis, sRAGE correlated with age (R = 0.22, p = 0.02) and the 24 hour albumin excretion rate (R = 0.18, p = 0.05), while esRAGE correlated positively with age only (R = 0.23, p = 0.02). In contrast to previous reports, neither sRAGE nor esRAGE correlated with glucose control or intima-media-thickness (IMT) as a predictor of macrovascular disease. In multivariate regression models, the associations between sRAGE and albuminuria as well as esRAGE and age were shown to be independent of glucose control, diabetes duration, body-mass index, glomerular filtration rate, blood pressure and gender., Conclusion: This is the first study comparing sRAGE and esRAGE as markers of vascular complications in patients with T2DM. sRAGE but not esRAGE is independently associated with albuminuria in these patients while neither sRAGE nor esRAGE are associated with markers of glucose control or macrovascular disease.

Background: Atherosclerosis is an inflammatory disease in which a perpetuated activation of NFkappaB via the RAGE (receptor for advanced glycation end products)-MAPK signalling pathway may play an important pathogenetic role. As recently S100 proteins have been identified as ligands of RAGE, we sought to determine the effects of the proinflammatory heterodimer of S100A8/S100A9 on the RAGE-NFkappaB mediated induction of proinflammatory gene expression., Methods: Human umbilical vein endothelial cells (HUVEC) were preincubated for 72 h with AGE-albumin or unmodified albumin for control, whereas AGE-albumin induction resulted in an upregulation of RAGE. Following this preactivation, cells were stimulated for 48 h with heterodimeric human recombinant S100A8/S100A9., Results: Heterodimeric S100A8/S100A9 enhanced secretion of IL-6, ICAM-1, VCAM-1 and MCP1 in AGE-albumin pretreated HUVEC in a dose dependent manner. These effects could not be detected after stimulation with the homodimeric proteins S100A8, S100A9, S100A1 and S100B. The effects of heterodimeric S100A8/S100A9 were reduced by inhibition of the MAP-kinase pathways ERK1/2 and p38 by PD 98059 and SB 203580, respectively., Conclusion: The heterodimeric S100A8/S100A9 might therefore play a hitherto unknown role in triggering atherosclerosis in diabetes and renal failure, pathophysiological entities associated with a high AGE burden. Thus, blocking heterodimeric S100A8/S100A9 might represent a novel therapeutic modality in treating atherosclerosis.

Leptin, the adipocyte-specific product of the ob gene, is implicated in body weight regulation and energy balance. We investigated the influence of hormone replacement therapy (HRT) on the body mass index (BMI) and serum leptin levels in 20 postmenopausal, nonobese women treated with transdermal HRT (delivery rate 50 microg 17beta-estradiol/24 h, 1 patch per week) for 6 months. Serum leptin levels were measured by ELISA and results were compared by means of the Student's paired t-test or Pearson's correlation. The mean patient age was 55+/-6.04 years. The mean body weight prior to the start of the study was 69.39+/-9.37 kg, and the BMI before HRT was 26.92+/-4.47 kg/m2. Both parameters remained unchanged under therapy. No significant change in absolute serum leptin values (18.8+/-8.4 ng/ml; 20.47+/-9.7 ng/ml; 17.92+/-8.7 ng/ml at 0, 4 and 6 months respectively) or in adiposity-corrected values (serum leptin/BMI) (0.68+/-0.24; 0.75+/-0.29; 0.67+/-0.26 at 0, 4 and 6 months respectively) were found. Serum leptin levels correlated well with BMI (r = 0.7193, p<0.0001). There was no significant correlation of estradiol with serum leptin levels before or during therapy. In summary, low dose, transdermal HRT exhibited no influence on serum leptin levels or BMI in postmenopausal women. These data suggest that low dose HRT does not influence body weight regulation in postmenopausal women.