Metabolic Syndrome and its Correlates among Hypertensive Patients in Abuja, North Central Nigeria

BACKGROUND

Metabolic syndrome is a constellation of abnormalities which includes central obesity, dyslipidaemia, elevated blood pressure and hyperglycemia. Hypertension, (which is a very common component of metabolic syndrome), and diabetes mellitus, are independently associated. Also, studies examining metabolic syndrome inAbuja, a city with affluence-driven lifestyle, are not available. This study aimed to investigate the prevalence of metabolic syndrome among hypertensive patients in Abuja, Nigeria, as well as to examine the associations between metabolic syndrome and certain factors in that cohort of hypertensive patients.

METHODS

This was a retrospective study that used data from hypertensive patients who attended clinic over a period of five years. Eight hundred and fifty-eight, (858-combined), case files of pre-treated, (previously known hypertensive patients) and newly diagnosed hypertensive participants were used for the study. The student t-tests were used to compare continuous variables, while Chi-square (χ2) tests were used for relationship between qualitative variables. The likelihood ratio test was employed to further confirm the statistical significance of certain independent variables relating with metabolic syndrome. A P-value of < 0.05 was considered statistically significant.

RESULTS

The mean ages were 48.70±12.18, 49.19±11.06 and 48.2±13.3 years for combined group, the pre-treated and the newly-diagnosed groups respectively. The pre-treated, group consists of those previously known hypertensive patients, while the new group consists of those who were newly diagnosed hypertensive patients and were treatment naïve. The prevalence of metabolic syndrome in this study was 45.5% in the combined group, 47.23% in the pre-treated group and 37.3% in the newly diagnosed group. The commonest component of metabolic syndrome was reduced high density lipoprotein cholesterol, HDL-C.

CONCLUSION

Metabolic syndrome is prevalent among hypertensive patients in Abuja, Nigeria. Some correlates of metabolic syndrome include; elevated BMI, truncal obesity, elevated total cholesterol, the use of thiazide diuretics and beta blockers as antihypertensives.

Precision Medicine Approach for Cardiometabolic Risk Factors in Therapeutic Apheresis

Lipoprotein apheresis (LA) is currently the most powerful intervention possible to reach a maximal reduction of lipids in patients with familial hypercholesterolemia and lipoprotein(a) hyperlipidemia. Although LA is an invasive method, it has few side effects and the best results in preventing further major cardiovascular events. It has been suggested that the highly significant reduction of cardiovascular complications in patients with severe lipid disorders achieved by LA is mediated not only by the potent reduction of lipid levels but also by the removal of other proinflammatory and proatherogenic factors. Here we performed a comprehensive proteomic analysis of patients on LA treatment using intra-individually a set of differently sized apheresis filters with the INUSpheresis system. This study revealed that proteomic analysis correlates well with routine clinical chemistry in these patients. The method is eminently suited to discover new biomarkers and risk factors for cardiovascular disease in these patients. Different filters achieve reduction and removal of proatherogenic proteins in different quantities. This includes not only apolipoproteins, C-reactive protein, fibrinogen, and plasminogen but also proteins like complement factor B (CFAB), protein AMBP, afamin, and the low affinity immunoglobulin gamma Fc region receptor III-A (FcγRIIIa) among others that have been described as atherosclerosis and metabolic vascular diseases promoting factors. We therefore conclude that future trials should be designed to develop an individualized therapy approach for patients on LA based on their metabolic and vascular risk profile. Furthermore, the power of such cascade filter treatment protocols may improve the prevention of cardiometabolic disease and its complications.

The transCampus Metabolic Training Programme Explores the Link of SARS-CoV-2 Virus to Metabolic Disease

Currently, we are experiencing a true pandemic of a communicable disease by the virus SARS-CoV-2 holding the whole world firmly in its grasp. Amazingly and unfortunately, this virus uses a metabolic and endocrine pathway via ACE2 to enter our cells causing damage and disease. Our international research training programme funded by the German Research Foundation has a clear mission to train the best students wherever they may come from to learn to tackle the enormous challenges of diabetes and its complications for our society. A modern training programme in diabetes and metabolism does not only involve a thorough understanding of classical physiology, biology and clinical diabetology but has to bring together an interdisciplinary team. With the arrival of the coronavirus pandemic, this prestigious and unique metabolic training programme is facing new challenges but also new opportunities. The consortium of the training programme has recognized early on the need for a guidance and for practical recommendations to cope with the COVID-19 pandemic for the community of patients with metabolic disease, obesity and diabetes. This involves the optimal management from surgical obesity programmes to medications and insulin replacement. We also established a global registry analyzing the dimension and role of metabolic disease including new onset diabetes potentially triggered by the virus. We have involved experts of infectious disease and virology to our faculty with this metabolic training programme to offer the full breadth and scope of expertise needed to meet these scientific challenges. We have all learned that this pandemic does not respect or heed any national borders and that we have to work together as a global community. We believe that this transCampus metabolic training programme provides a prime example how an international team of established experts in the field of metabolism can work together with students from all over the world to address a new pandemic.

Lipoprotein(a) and proprotein convertase subtilisin/kexin type 9 inhibitors

Lipoprotein(a) (Lp(a)) is an internationally accepted independent atherogenic risk factor. Details about its synthesis, many aspects of composition and clearance from the bloodstream are still unknown. LDL receptor (LDLR) (and probably other receptors) play a role in the elimination of Lp(a) particles. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors increase the number of available LDLRs and in this way very effectively reduce the LDL cholesterol (LDL-C) concentrations. As shown in controlled studies using PCSK9 inhibitors, Lp(a) levels are decreased by 20 to 30%, though in some patients no effect was observed. So far, it has not been clarified whether this decrease is associated with an effect on the incidence of cardiovascular events (CVEs). In two recently published well-performed secondary prevention studies (FOURIER with evolocumab, ODYSSEY OUTCOMES with alirocumab) baseline Lp(a) levels were shown to have an impact on CVEs independently of baseline LDL-C concentrations. The rather modest PCSK9 inhibitor-induced decrease of Lp(a) was associated with a reduction of CVEs in both studies, even after adjusting (ODYSSEY OUTCOMES) for demographic variables (age, sex, race, region), baseline Lp(a), baseline LDL-C, change in LDL-C, and clinical variables (time from acute coronary syndrome, body mass index, diabetes, smoking history). The largest decrease of CVEs was seen in patients with relatively low concentrations of both LDL-C and Lp(a) (FOURIER). These findings will probably have an influence on the use of PCSK9 inhibitors in patients with high Lp(a) concentrations.

P6285Protective effects of exercise on vascular function are mediated by NADPH oxidase 4

Background/Introduction

Physical activity is one of the most potent strategies to prevent endothelial dysfunction. Recent evidence indicates vaso-protective properties of H2O2 produced by main endothelial NADPH oxidase isoform 4 (Nox4) in the vasculature.

Purpose

Therefore, we hypothesized that Nox4 connects physical activity with vaso-protective effects.

Methods and results

Analysis of endothelial function by Mulvany myograph showed endothelial dysfunction in wild-type as well as in Nox4−/− mice after 20 weeks on high-fat diet. Access to voluntary running wheels during high-fat diet prevented endothelial dysfunction in wild-type but not in Nox4−/− mice. Mechanistically, exercise led to increased H2O2 release in the aorta of wild-type mice with increased phosphorylation of eNOS pathway member AKT serine/threonine kinase 1 (Akt1), subsequently. Both effects were diminished in aortas of Nox4−/− mice. Deletion of Nox4 also led to decreased capacity for intracellular calcium release and reduced phenylephrine-mediated contraction, whereas potassium-induced contraction was unaffected. H2O2 scavenger catalase reduced phenylephrine-contraction in wild-type mice. Supplementation of H2O2 increased phenylephrine-induced contraction in Nox4−/− mice. Exercise induced key regulator of mitochondria biogenesis peroxisome proliferative activated receptor gamma, coactivator 1 alpha (Ppargc1a) in wild-type but not Nox4−/− mice. Furthermore, exercise induced citrate synthase activity and reduced mitochondria mass in the absence of Nox4. Thus, Nox4−/− mice became less active and ran less compared with wild-type mice.

Conclusions

Nox4 derived H2O2 plays a key role in exercise-induced adaptations of eNOS and Ppargc1a pathway and intracellular calcium release. Hence, loss of Nox4 diminished physical activity performance and vascular protective effects of exercise.

Acknowledgement/Funding

This work was supported by a research grant of the German Cardiac Society (DGK) (to H.L.) and DFG (Grant MO 1695/4-1 to H.M.).

Plasma Steroid Profiles in Subclinical Compared With Overt Adrenal Cushing Syndrome

CONTEXT

Diagnosis of subclinical adrenal hypercortisolism is based on several tests of the hypothalamic-pituitary-adrenal axis to establish mild alterations of cortisol secretion and dysregulated cortisol physiology.

OBJECTIVE

We assessed whether plasma steroid profiles might assist diagnosis of subclinical Cushing syndrome (SC).

DESIGN

Retrospective cross-sectional study.

SETTING

Two tertiary medical centers.

PATIENTS

Of 208 patients tested for hypercortisolism, disease was excluded in 152 and confirmed in 21 with overt adrenal Cushing syndrome (AC) compared to 35 with SC. Another 277 age- and sex-matched hypertensive and normotensive volunteers were included for reference.

MAIN OUTCOME MEASURES

A panel of 15 plasma steroids was measured by mass spectrometry, with classification by discriminant analysis.

RESULTS

Patients with SC had lower plasma concentrations of dehydroepiandrosterone and dehydroepiandrosterone-sulfate than subjects without SC (P < 0.05). The largest increases (P < 0.001) in plasma steroids among patients with SC were observed for 11-deoxycortisol and 11-deoxycorticosterone. Nevertheless, concentrations of 11-deoxycorticosterone, 11-deoxycortisol, and pregnenolone in patients with AC were higher (P < 0.05) than in those with SC. Patients with SC or AC could be distinguished from subjects without disease using this combination of steroids as precisely as with use of measurements of serum cortisol after administration of dexamethasone. The steroid combination provided superior diagnostic performance compared with each of the other routine biochemical tests.

CONCLUSION

Distinct plasma steroid profiles in patients with SC may provide a simple and reliable screening method for establishing the diagnosis.

Lipoprotein(a): the underutilized risk factor for cardiovascular disease

Raised lipoprotein(a) [Lp(a)] is an important independent cardiovascular risk factor and predictor of adverse outcomes. Challenges remain with regards to the screening, diagnosis and management of this condition. Although further prospective randomised controlled data is required, there is growing evidence suggesting that lowering Lp(a) may reduce the risk of cardiovascular events and ameliorate symptoms.

Lipoprotein(a)-an interdisciplinary challenge

Lipoprotein(a) (Lp(a)) is an internationally recognized atherogenic risk factor which is inherited and not changed by nutrition or physical activity. At present, only proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors may modestly decrease its concentration (but not in all patients)-leading to a certain decrease in cardiovascular events (CVE) in controlled studies. However, at present an elevation of Lp(a) is not a generally accepted indication for their use. More effective is lipoprotein apheresis (LA) therapy with respect to both lowering Lp(a) levels and reduction of CVE. In the future, an antisense oligonucleotide against apolipoprotein(a) will probably be available. Atherosclerosis in patients with an elevation of Lp(a) may affect several vessel regions (carotids, aorta, coronaries, leg arteries). Thus, Lp(a) should be measured in high-risk patients. These patients are usually cared for by their family doctors and by other specialists who should closely cooperate. Lipidologists should decide whether costly therapies like PCSK9 inhibitors or LA should be started. The main aim of current therapy is to optimize all other risk factors (LDL cholesterol, hypertension, diabetes mellitus, body weight, renal insufficiency). Patients should be regularly monitored (lab data, heart, arteries). This paper describes the duties of physicians of different specialties when caring for patients with high Lp(a) concentrations.

Inherited anxiety-related parent-infant dyads alter LHPA activity

The pathogenesis of post-traumatic stress disorder (PTSD) is incompletely understood. We hypothesize that disruptions in mother-child relations may be a key contributor to development of PTSD. A normal and healthy separation-individuation process requires adaptations of self- and interactive contingency in both the mother and her child, especially in early childhood development. Anxious mothers are prone to overprotection, which may hinder the individuation process in their children. We examined long-term stress hormones and other stress markers in subjects three generations removed from the Holocaust, to assess the long-term consequences of inherited behavioral and physiological responses to prior stress and trauma. Jewish subjects who recalled overprotective parental behavior had higher hairsteroid-concentrations and dampened limbic-hypothalamic-pituitary-adrenal (LHPA) axis reactivity compared to German and Russian-German subjects with overprotective parents. We suggest that altered LHPA axis activity in maternally overprotected Jewish subjects may indicate a transmitted pathomechanism of "frustrated individuation" resulting from cross-generational anti-Semitic experiences. Thus measurements of hairsteroid-concentrations and parenting practices may have clinical value for diagnosis of PTSD. We propose that this apparent inherited adaptivity of LHPA axis activity could promote higher individual stress resistance, albeit with risk of an allostatic overload.

Intensive lifestyle modifications with or without liraglutide 3mg vs. sleeve gastrectomy: A three-arm non-randomised, controlled, pilot study

BACKGROUND/OBJECTIVES

As only 1% of clinically eligible subjects choose to undergo surgical treatment for obesity, other options should be investigated. This study aimed to assess the effects of intensive lifestyle modification (ILM) with or without 3-mg liraglutide daily vs. sleeve gastrectomy (SG) on BMI after 1 year.

SUBJECTS/METHODS

In this study performed at an Italian university hospital, non-diabetic patients eligible for bariatric surgery were recruited from a weight-loss clinic and had the option to choose from three possible weight-loss programmes up to an allocation of 25 subjects in each arm matched by BMI and age. ILM consisted in 813kcal of a very low-calorie diet (VLCD) for 1 month, followed by a diet of 12kcal/kg body weight of high protein and high fat for 11 months plus 30min of brisk walking daily and at least 3h of aerobic exercise weekly. SG patients followed a VLCD for 1 month and a free diet thereafter. Patients were evaluated at baseline and at 1, 3, 6, 9 and 12 months.

RESULTS

A total of 75 patients were enrolled; retention was 100% in the SG and 85% in the two medical arms. SG reduced BMI by 32% (P<0.001 vs. medical arm), while ILM+liraglutide and ILM led to BMI reductions of 24% and 14%, respectively (P<0.001). More women allocated themselves to the ILM+liraglutide group. Weight loss was 43kg with SG, 26kg with ILM+liraglutide and 15kg with ILM alone. Lean body mass reductions were -11.6kg with SG, -6.3kg with ILM and -8.3kg with ILM+liraglutide. Prevalence of prediabetes was significantly lower with ILM+liraglutide, and insulin resistance was reduced by about 70% by both ILM+liraglutide and SG vs. 39% by ILM alone. Cardiometabolic risk factors were greatly reduced in all three groups.

DISCUSSION

At least in the short-term, liraglutide 3.0mg once daily associated with drastic calorie-intake restriction and intensive physical activity promoted a 24% weight loss, which was almost two times greater than ILM alone and only about 25% less than with SG, while preserving lean body mass. Although this study was non-randomised, it was designed to explore the efficacy of medical treatments for obesity in everyday clinical practice.

Lipoprotein apheresis influences monocyte subpopulations

BACKGROUND

Monocytes can be differentiated into subpopulations depending on their expression profile of CD14 and CD16. CD16-positive monocytes are associated with coronary artery disease. Up to now, no data exist about the effect of lipoprotein apheresis (LA) on the distribution of monocyte subpopulations.

METHODS

80 patients who underwent LA at the University Hospital Dresden were included in the study. 8 out of the 80 LA patients received LA for the first time at the time point of blood analysis. Six different methods of LA were used (H.E.L.P. n = 8; Liposorber D n = 10; LF n = 14; DALI n = 17; MONET n = 11; Therasorb^® LDL n = 12). Blood samples were taken immediately before and after LA and analyzed for CD14 and CD16 expression on monocytes. A total of 42 patients with cardiovascular risk factors but no indication for LA served as control group.

RESULTS

The composition of monocyte-population was analyzed in regard to the 3 subpopulations. After LA, an increase in classical monocytes (CD14⁺⁺CD16^-) (93.3% vs. 93.9%, p < 0.01) and a decrease in non-classical monocytes (CD14⁺CD16⁺) (1.5% vs 1.0%; p < 0.001) were observed. LA did not change the amount of intermediate monocytes (CD14⁺⁺CD16⁺) (5.3% vs. 5.1%). Two methods (MONET and Therasorb^® LDL) did not influence the distribution of monocyte subpopulations. Interestingly, patients with LDL-C above 2.5 mmol/l prior LA showed increased amounts of intermediate monocytes.

CONCLUSION

The distribution of monocyte populations is influenced by LA but depends on the distinct method of LA. Influences of LA were mainly observed in the content of classical and non-classical monocytes, whereas the intermediate monocyte population remained unaltered by LA.

Dysregulation of the CD4+ T cells lineage differentiation in dyslipidemic patients and impact of lipoprotein-apheresis treatment: A case study

BACKGROUND AND AIM

Lipoprotein-apheresis (LA) is a therapeutic approach used against severe forms of dyslipidemia in patients who are non-responders or intolerant to pharmacological treatments. However, little is known about the potential pleiotropic effects of LA, particularly regarding the immune system and its regulation. Thus, in an attempt to analyse the potential effects of dyslipidemia and LA on the regulation of CD4+ T cells activation and lineage differentiation, we compared the CD4+ T cells cytokines secretion profiles of dyslipidemic patients before and after LA with the profiles observed in healthy donors.

METHODS

CD4+ T cells were isolated from 5 LA patients and 5 healthy donors and activated with anti-CD3 or anti-CD3 + anti-CD46 antibodies. The supernatants were collected after 36 h incubation and levels of secreted cytokines analysed by flow cytometry.

RESULTS

Our results revealed a deep remodelling of CD4+ T cells cytokines secretion patterns in dyslipidemic patients compared to healthy donors, as reflected by a 15 times higher IFN-γ secretion rate after CD3 + CD46 co-activation in dyslipidemic patients after LA compared to healthy subjects and 8 times higher after CD3 activation alone (p = 0.0187 and p = 0.0118 respectively). Moreover, we demonstrated that LA itself also modifies the phenotype and activation pattern of CD4+ T-cells in dyslipidemic patients.

CONCLUSION

These observations could be of fundamental importance in the improvement of LA columns/systems engineering and in developing new therapeutic approaches regarding dyslipidemia and associated pathologies such as atherosclerosis and type 2 diabetes.

The PHF21B gene is associated with major depression and modulates the stress response

Major depressive disorder (MDD) affects around 350 million people worldwide; however, the underlying genetic basis remains largely unknown. In this study, we took into account that MDD is a gene-environment disorder, in which stress is a critical component, and used whole-genome screening of functional variants to investigate the 'missing heritability' in MDD. Genome-wide association studies (GWAS) using single- and multi-locus linear mixed-effect models were performed in a Los Angeles Mexican-American cohort (196 controls, 203 MDD) and in a replication European-ancestry cohort (499 controls, 473 MDD). Our analyses took into consideration the stress levels in the control populations. The Mexican-American controls, comprised primarily of recent immigrants, had high levels of stress due to acculturation issues and the European-ancestry controls with high stress levels were given higher weights in our analysis. We identified 44 common and rare functional variants associated with mild to moderate MDD in the Mexican-American cohort (genome-wide false discovery rate, FDR, <0.05), and their pathway analysis revealed that the three top overrepresented Gene Ontology (GO) processes were innate immune response, glutamate receptor signaling and detection of chemical stimulus in smell sensory perception. Rare variant analysis replicated the association of the PHF21B gene in the ethnically unrelated European-ancestry cohort. The TRPM2 gene, previously implicated in mood disorders, may also be considered replicated by our analyses. Whole-genome sequencing analyses of a subset of the cohorts revealed that European-ancestry individuals have a significantly reduced (50%) number of single nucleotide variants compared with Mexican-American individuals, and for this reason the role of rare variants may vary across populations. PHF21b variants contribute significantly to differences in the levels of expression of this gene in several brain areas, including the hippocampus. Furthermore, using an animal model of stress, we found that Phf21b hippocampal gene expression is significantly decreased in animals resilient to chronic restraint stress when compared with non-chronically stressed animals. Together, our results reveal that including stress level data enables the identification of novel rare functional variants associated with MDD.

Persistent LHPA Activation in German Individuals Raised in an Overprotective Parental Behavior

Parental upbringing may affect their offspring’s mental state across the entire lifespan. Overprotective parental child-rearing style may increase the disease burden in the offspring. Furthermore, this child-rearing style may also play a pathogenetic role by transmitting trauma- and stressor-related disorders (TSRD) across generations. Studies with animals have demonstrated that the mother’s immediate and expansive protection of the newborn decreases the limbic-hypothalamic-pituitary-adrenal (LHPA) axis activity in the offspring. However, few studies have investigated how stress impact humans raised in an overprotective manner. In a cross-sectional study with 40 healthy students recalling their overprotective upbringing, we show an increase in the dehydroepiandrostendione (DHEA) concentration and a reduction in the cortisol/DHEA-ratio in hair. Additionally, this child rearing style was associated with heightened indications of mental burden, depressiveness, and sense of coherence. Our results provide insight into the roots and consequences of psychological trauma across several generations. Further investigations focusing particularly on multigenerational transmission in extremely burdened families will augment our results.

Serum and Plasma Levels of Vascular Endothelial Growth Factors in Relation to Quality of Glucose Control, Biomarkers of Inflammation, and Diabetic Nephropathy

Levels of vascular endothelial growth factors (VEGF) are regulated in a complex network of adipokines, glucose control, and low grade inflammation together with activated platelets, leucocytes, and endothelial dysfunction. Increased levels of VEGF are associated with enhanced angiogenesis and impaired repair mechanisms of vascular lesions in endorgans. Little is known about the interaction of systemic VEGF levels with quality of diabetes control, biomarkers of inflammation, and diabetic nephropathy. Moreover, it is unclear, whether serum and plasma VEGF levels are similarly suited to reflect risk associated with VEGF.In this case control study, we analyzed these parameters in serum and plasma of age and sex matched controls without diabetes (n=99) and type 2 diabetes (n=302). Serum VEGF-A was significantly increased in patients with T2DM while plasma levels were in the same range as for controls. Individual levels varied in a wide range. Serum levels were 4.9 times higher in controls and 7.3 times higher in T2DM as compared to plasma levels. T2DM was associated with significantly higher levels of hsCRP, ALAT, and albumin/creatinine ratio. When calculated for tertiles of HbA1c, we observed a highly significant increase from tertile one to the upper tertile for serum VEGF-A but not for plasma VEGF-A. Correlation analysis revealed a significant relationship between VEGF-A, HbA1c, inflammation, and diabetic nephropathy. Our results indicate that increased VEGF-A levels in T2DM significantly depend on quality of HbA1c control. Serum levels of VEGF-A, with a strong contribution of platelet derived VEGF, better reflect the glycemic burden than plasma levels of VEGF-A. Mechanistic studies are needed to explore links to inflammation and diabetic nephropathy.

STAT3-Ser/Hes3 Signaling: A New Molecular Component of the Neuroendocrine System?

The endocrine system involves communication among different tissues in distinct organs, including the pancreas and components of the Hypothalamic-Pituitary-Adrenal Axis. The molecular mechanisms underlying these complex interactions are a subject of intense study as they may hold clues for the progression and treatment of a variety of metabolic and degenerative diseases. A plethora of signaling pathways, activated by hormones and other endocrine factors have been implicated in this communication. Recent advances in the stem cell field introduce a new level of complexity: adult progenitor cells appear to utilize distinct signaling pathways than the more mature cells in the tissue they co-reside. It is therefore important to elucidate the signal transduction requirements of adult progenitor cells in addition to those of mature cells. Recent evidence suggests that a common non-canonical signaling pathway regulates adult progenitors in several different tissues, rendering it as a potentially valuable starting point to explore their biology. The STAT3-Ser/Hes3 Signaling Axis was first identified as a major regulator of neural stem cells and, subsequently, cancer stem cells. In the endocrine/neuroendocrine system, this pathway operates on several levels, regulating other types of plastic cells: (a) it regulates pancreatic islet cell function and insulin release; (b) insulin in turn activates the pathway in broadly distributed neural progenitors and possibly also hypothalamic tanycytes, cells with important roles in the control of the adrenal gland; (c) adrenal progenitors themselves operate this pathway. The STAT3-Ser/Hes3 Signaling Axis therefore deserves additional research in the context of endocrinology.

Crosstalk Between Glycoxidative Modification of Low-Density Lipoprotein, Angiotensin II-Sensitization, and Adrenocortical Aldosterone Release

Low-density lipoprotein (LDL) is considered to be a risk factor for atherosclerosis. In the presence of hyperglycemia, LDL undergoes glycoxidative modification and this glycoxidized (glycox) LDL promotes atherosclerosis in type 2 diabetic (T2D) individuals. Moreover, because of its cholesterol content, LDL contributes to aldosterone biosynthesis, which is modulated by angiotensin II (AngII) and has been implicated in cardiovascular complications of T2D. However, the molecular mechanism of the crosstalk between glycoxLDL, AngII, and aldosterone has not been explained clearly. Therefore, this study has been aimed to investigate the impact of in vitro modified glycoxLDL on aldosterone release in an AngII-sensitized adrenocortical carcinoma cell line (NCI H295R). Native LDL (natLDL), isolated from healthy volunteers by sequential density gradient ultracentrifugation, was subjected to d-glucose (200 mmol/l), for glycoxidative modification, at 37 °C for 6 days. The AngII-sensitized H295R cells were treated with natLDL and glycoxLDL for 24 h and the supernatant was used for aldosterone measurement. The treated cells were utilized for protein isolation and mRNA quantification. Compared to natLDL, glycoxLDL produced a significantly greater effect on aldosterone release from AngII-sensitized cells. The treatment with specific pharmacological inhibitors suggests that modified LDL recruits ERK1/2 and janus kinase-2 for transcriptional regulation of aldosterone synthase. Moreover, glycoxLDL modulates aldosterone release via cAMP-dependent protein kinase A (PKA) pathway. However, glycoxLDL induces ERK phosphorylation independent of PKA activation and this novel mechanism could be targeted for therapeutic trials. In conclusion, this in vitro study emphasizes a possible causal relationship between LDL glycoxidative modification, AngII-sensitization, and adrenocortical steroid hormone release.

Anti-inflammatory properties of bone morphogenetic protein 4 in human adipocytes

BACKGROUND

Obesity is characterized by increased adipocyte number and size as well as white adipose tissue (WAT) inflammation, which is fundamental for the development of insulin resistance and type-2 diabetes. These processes, regulated by various endocrine, paracrine and autocrine factors, are extensively studied with the hope to interfere and to inhibit weight gain and related complications in obese patients. Recent data suggest an important role of bone morphogenic protein 4 (BMP4) in the regulation of adipogenesis and development of obesity. BMP4 is a growth factor of the transforming growth factor-β superfamily. Initially, BMPs were identified as inducers of ectopic bone formation. It is now apparent, however, that these proteins have different pleiotropic developmental actions and including playing a role in white adipogenesis.

METHODS AND RESULTS

Here, we demonstrate that the expression of BMP4 in human WAT is negatively correlated to body mass index and to the expression of pro-inflammatory cytokines. In vitro, BMP4 expression in cultured human adipocytes is upregulated after induction of differentiation. Cells treated with exogenous BMP4 increased peroxisome proliferator-activated receptor γ (PPARγ) expression and significantly reduced the expression of pro-inflammatory cytokines including tumor necrosis factor α (TNF-α) and monocyte chemoattractant protein 1. TNF-α treatment of fully differentiated adipocytes resulted in downregulation of the expression of adipogenic genes and elevated expression of pro-inflammatory cytokines. Exogenous BMP4 addition significantly reduced the negative effect of TNF-α on the expression profile of adipocytes. Finally, treatment of human adipocytes with exogenous BMP4 reduced the adipocytes' chemoattractant potential and the migration of monocytes toward adipocyte-conditioned medium.

CONCLUSIONS

These results indicate that BMP4 is an important anti-inflammatory molecule, which may act through PPARγ and reduces TNF-α-mediated pro-inflammatory cytokine production in human adipocytes. Through its anti-inflammatory potential, BMP4 may serve as a protective factor for inflammation-related diseases such as insulin-tolerance or type-2 diabetes.

Lipidomic profiling at the interface of metabolic surgery and cardiovascular disease

Bariatric surgery has helped patients attain not only significant and sustained weight loss but has also proved to be an effective means of mitigating or reversing various obesity-related comorbidities. The impressive rates of remission or resolution of type 2 diabetes mellitus (T2D) following bariatric surgery are well documented and have rightly received great attention. Less understood are the effects of bariatric surgery on cardiovascular disease (CVD) and its underlying risk factors. Thanks to the availability of increasingly sensitive laboratory tools, the emerging science of lipidomics and metagenomics is poised to offer significant contributions to our understanding of metabolically induced vascular diseases. They are set to identify novel mechanisms explaining how the varied approaches of bariatric surgery produce the remarkable improvements in multiple organs observed during patient follow-up. This article reviews recent and novel findings in patients through the lens of lipidomics with an emphasis on CVD.

Increased gene expression of the cardiac endothelin system in obese mice

Obesity is a well-known risk factor of atherosclerosis and heart failure. In the human heart, a local endothelin system containing prepro-endothelin-1, endothelin-converting enzyme-1, and endothelin receptors A and B has been described. The endothelin system is activated in heart failure; however, the impact of obesity on the cardiac endothelin system is unknown. In this study, 18-week-old male C57BL/6 mice fed either a control diet or a high-fat diet for 10 weeks were analyzed. High-fat diet significantly increased the body weight of the animals and augmented low-density lipoprotein, high-density lipoprotein, and cholesterol plasma levels, compared to control. The animal groups showed no significant differences in left ventricular size or function (heart rate, ejection fraction, fractional shortening, left ventricular posterior wall thickness, cardiac output) after control or high-fat diet. We did not observe signs of cardiac hypertrophy or changes in markers of cardiac fibrosis in these heart samples. The cardiac expression of prepro-endothelin-1 mRNA, endothelin-converting enzyme-1 mRNA, and protein and endothelin receptors A and B mRNA was increased in 18-week-old obese C57BL/6 mice compared to animals with normal weight (p<0.05 vs. control). Furthermore, endothelin-1 plasma levels showed an increasing trend. In conclusion, an increased expression of genes of the endothelin system was observed in the hearts of 18-week-old mice after high-fat diet, possibly contributing to later cardiovascular complications of obesity.

Modification of human islet preparation: an effective approach to improve graft outcome after islet transplantation?

Revascularisation of transplanted islets is an essential prerequisite for graft survival and function. However, current islet isolation procedures deprive the islets of endothelial tubulets. This may have a detrimental effect on the revascularisation process of islets following transplantation. We hypothesise that modification of the isolation procedure that preserves islet endothelial vessels may improve the islet revascularisation process following transplantation. Here, we present a modified islet isolation method by which a substantial amount of endothelial cells still attached to the islets could be preserved. The islets with preserved endothelial cells isolated by this method were revascularised within 3 days, not observed in islets isolated by standard methods. Further, we observed that grafts of islets isolated by standard methods had more patches of dead tissue than islet grafts obtained by the modified method, indicating that attached endothelial cells may play an important role in the islet revascularisation process and potentially help to improve the transplantation outcome.

Humanized mouse models for type 1 diabetes including pancreatic islet transplantation

We comment here on the suitability of available mouse models for type 1 diabetes research including research on therapeutic pancreatic islet transplantation. The major emphasis will be laid on models that require minimal invasive procedures. Most biological processes are too complex for a complete recapitulation in a test tube. The study of innate or even adaptive immune responses involves a number of different cell types and organs making in vitro studies unreliable but also providing extreme challenges for the use of surrogate model organisms. Studying these processes directly in humans is impossible due to ethical and technical constraints. To resolve this problem small animal models such as mice or rats are frequently used to study mechanisms of complex diseases. This has brought much insight into hematopoiesis and immune cell function including type 1 diabetes (T1D); however, 65 million years of evolution introduced striking differences between mice and humans 1. In fact, none of the many suggested therapies arising from studies using mice 2 3 that have promised prevention or even reversion of T1D made it into the clinic yet 4 5 6. The reason for this are major species-specific differences between rodents and humans regarding the immune system and beta cells.

Incretins or anti-incretins? A new model for the "entero-pancreatic axis"

The role of incretins in glucose homeostasis is well known. Yet, in recent years, the sustained weight loss and rapid glycemic control following bariatric surgery has challenged our understanding of the intestinal-pancreatic interaction. This in turn led to the introduction of metabolic surgery, an innovative medical discipline in which a surgical manipulation of the gastrointestinal tract (e. g., through a Roux-en-Y gastric bypass, RYGB, or Bilio-Pancreatic-Diversion, BPD) yields a sustained remission of diabetes mellitus. The pathophysiological background of this metabolic effect is, amongst other things, based on the anti-incretin theory. This theory postulates that in addition to the well-known incretin effect, nutrient passage through the GI-tract could also activate negative feedback mechanisms (anti-incretins) to balance the effects of incretins and other postprandial glucose-lowering mechanisms (i. e., suppression of ghrelin, glucagon, and hepatic glucose production via activation of nutrient sensing). This in turn prevents postprandial hyperinsulinemic hypoglycemia. The bypass of the duodenum, the entire jejunum and the first portion of the ileum by BPD induce normalization of peripheral insulin sensitivity, while the bypass of a shorter intestinal tract by RYGB mainly improves the hepatic insulin sensitivity. In addition, RYGB greatly increases insulin secretion. Therefore, metabolic surgery highlights the important role of the small intestine in glucose homeostasis, while until few years ago, it was only the pancreas and the liver that were thought to represent the regulatory organs for glucose disposal.

Islet transplantation at the Dresden diabetes center: five years' experience

For the majority of patients with type 1 diabetes intensive insulin therapy is effective and safe for maintaining glycemia and minimizing diabetes-associated complications. However, a rare number of patients show highly labile metabolic control and experience repeated and unpredictable hypoglycemic episodes. Such condition is often caused by defective counterregulatory mechanisms and autonomous neuropathy. Patients are at high risk for severe acute and chronic complications, and quality of life is considerably impaired. For this small subset of patients, restoration of endogenous insulin secretion can substantially improve metabolic control and quality of life. In our experience, this is irrespective of insulin independency. Here, we report on our 5 years' experience with implementing islet transplantation as a potential treatment option for type 1 diabetes. All patients were treated by long-term insulin pump therapy prior to enrolment. The main indication was severely unstable diabetes and repeated hypoglycemia. From 2008 to 2013, 10 patients have been transplanted with single islet infusion; mean follow-up time was 35 months. All patients show persistent graft function, stable glycemic control with a reduction in HbA1c in the absence of hypoglycemia. All patients are kept on minimal exogenous insulin. In conclusion, islet transplantation can be an excellent therapy for selected patients. Key prerequisite for success is a strict indication. The primary goal for islet transplantation should be stabile glycemia and prevention of hypoglycemia rather than insulin independence. In fact, maintaining minimal exogenous insulin may protect the islet graft from metabolic stress and even prolong islet graft function.

Oxygen supply by photosynthesis to an implantable islet cell device

Transplantation of islet cells is an effective treatment for type 1 diabetes with critically labile metabolic control. However, during islet isolation, blood supply is disrupted, and the transport of nutrients/metabolites to and from the islet cells occurs entirely by diffusion. Adequate oxygen supply is essential for function/survival of islet cells and is the limiting factor for graft integrity. Recently, we developed an immunoisolated chamber system for transplantation of human islets without immunosuppression. This system depended on daily oxygen supply. To provide independence from this external source, we incorporated a novel approach based on photosynthetically-generated oxygen. The chamber system was packed sandwich-like with a slab of immobilized photosynthetically active microorganisms (Synechococcus lividus) on top of a flat light source (LEDs, red light at 660 nm, intensity of 8 μE/m(2)/s). Islet cells immobilized in an alginate slab (500-1,000 islet equivalents/cm(2)) were mounted on the photosynthetic slab separated by a gas permeable silicone rubber-Teflon membrane, and the complete module was sealed with a microporous polytetrafluorethylene (Teflon) membrane (pore size: 0.4 μm) to protect the contents from the host immune cells. Upon illumination, oxygen produced by photosynthesis diffused via the silicone Teflon membrane into the islet compartment. Oxygen production from implanted encapsulated microorganisms was stable for 1 month. After implantation of the device into diabetic rats, normoglycemia was achieved for 1 week. Upon retrieval of the device, blood glucose levels returned to the diabetic state. Our results demonstrate that an implanted photosynthetic bioreactor can supply oxygen to transplanted islets and thus maintain islet viability/functionality.

Xenotransplantation of porcine islet cells as a potential option for the treatment of type 1 diabetes in the future

Solid organ and cell transplantation, including pancreatic islets constitute the treatment of choice for chronic terminal diseases. However, the clinical use of allogeneic transplantation is limited by the growing shortage of human organs. This has prompted us to initiate a unique multi-center and multi-team effort to promote translational research in xenotransplantation to bring xenotransplantation to the clinical setting. Supported by the German Research Foundation, an interdisciplinary group of surgeons, internal medicine doctors, diabetologists, material sciences experts, immunologists, cell biologists, virologists, veterinarians, and geneticists have established a collaborative research center (CRC) focusing on the biology of xenogeneic cell, tissue, and organ transplantation. A major strength of this consortium is the inclusion of members of the regulatory bodies, including the Paul-Ehrlich Institute (PEI), infection specialists from the Robert Koch Institute and PEI, veterinarians from the German Primate Center, and representatives of influential ethical and religious institutions. A major goal of this consortium is to promote islet xenotransplantation, based on the extensive expertise and experience of the existing clinical islet transplantation program. Besides comprehensive approaches to understand and prevent inflammation-mediated islet xenotransplant dysfunction [immediate blood-mediated inflammatory reaction (IBMIR)], we also take advantage of the availability of and experience with islet macroencapsulation, with the goal to improve graft survival and function. This consortium harbors a unique group of scientists with complementary expertise under a cohesive program aiming at developing new therapeutic approaches for islet replacement and solid organ xenotransplantation.

Genetics and the clinical approach to paragangliomas

This study analyses new information on gene mutations in paragangliomas and puts them into a clinical context. A suspicion of malignancy is critical to determine the workup and surgical approach in adrenal (A-PGL) and extra-adrenal (E-PGL) paragangliomas (PGLs). Malignancy rates vary with location, family history, and gene tests results. Currently there is no algorithm incorporating the above information for clinical use. A sum of 1,821 articles were retrieved from PubMed using the search terms "paraganglioma genetics". Thirty-seven articles were selected of which 9 were analyzed. It was found that 599/2,487 (24%) patients affected with paragangliomas had a germline mutation. Of these 30.2% were mutations in SDHB, 25% VHL, 19.4% RET, 18.4% SDHD, 5.0% NF1, and 2.0% SDHC genes. A family history was positive in 18.1-64.3% of patients. Adrenal PGLs accounted for 55.1% in mutation (+) and 81.0% in mutation (-) patients (RR 1.2, p < 0.0001). Bilateral A-PGLs accounted for 56.4% in mutation (+) and 3.2% in mutation (-) patients (RR 8.7, p < 0.0001). E-PGL were found in 33.6% of mut+ and 17.3% of mut- (RR 1.7, p < 0.0001). In mutation (+) patients PGLs malignancy varied with location, adrenal (6.4%) thoraco-abdominal E-PGL (38%), H & N E-PGL (10%). Malignancy rates were 8.2% in mutation (-) and lower in mutation (+) PGLs except for SDHB 36.5% and SDHC 8.3%. Exclusion of a mutation lowered the probability of malignancy significantly in E-PGL (RR 0.03 (95% CI 0.1-0.6); p < 0.001). Mutation analysis provides valuable preoperative information to assess the risk of malignancy in A-PG and E-PGLs and should be considered in the work up of all E-PGL lesions.

Oncologic resection achieving r0 margins improves disease-free survival in parathyroid cancer

BACKGROUND

Parathyroid cancer has a poor mid-term prognosis, often because of local recurrence, observed in half of all patients. Modern diagnostic workup increasingly enables a preoperative diagnosis of parathyroid cancer. There is limited evidence that more comprehensive oncologic surgery can reduce the risk of local recurrence. This study aims to identify the best specific surgical approach in parathyroid cancer.

METHODS

This observational cohort study comprises 19 consecutive patients who had undergone oncologic or nononcologic resection for parathyroid cancer. Baseline parameters were compared by using univariate analysis; outcomes were assessed by χ (2) testing and Kaplan-Meier statistics.

RESULTS

Fifteen of 19 patients were primarily operated on in our tertiary center between 1996 and 2013, and four were referred for follow-up because of their cancer diagnosis. Patient cohorts defined by histologic R-status were comparable for established risk factors: sex, calcium levels, low-risk/high-risk status, and presence of vascular invasion. Oncologic resections were performed in 13 of 15 patients primarily treated in the center and 0 of 4 treated elsewhere (χ (2) = 5.6; p < 0.01). R0 margins were achieved in 11 of 13 (85 %) undergoing oncologic resection and 1 of 6 (17 %) undergoing local excision (χ (2) = 8.1; p < 0.01). R0 margins and primary oncologic resection were associated with higher disease-free survival rates (χ (2) = 7.9; p = 0.005 and χ (2) = 4.7; p = 0.03, respectively). Revision surgery achieved R0 margins in only 2 of 4 (50 %) of patients.

CONCLUSIONS

In parathyroid cancer, a more comprehensive surgery (primary oncologic resection) provides significantly better outcomes than local excision as a result of reduction of R1 margins and locoregional recurrence.

Calcium-dependent release of adipocyte fatty acid binding protein from human adipocytes

BACKGROUND

Fatty acid binding protein 4 (FABP4) is a predominantly cytosolic protein of the adipocytes, but also abundantly present in human plasma; its plasma concentrations were linked to obesity and metabolic syndrome. Recent studies have suggested a direct extracellular effect of FABP4 in the regulation of glucose metabolism and heart function independently of its effect as a carrier protein. Interestingly, FABP4 has no secretory signal sequence; hence, the mechanisms how FABP4 is released from adipocytes are unclear.

METHODS AND RESULTS

In this study we investigated the mechanisms for FABP4 secretion from human adipocytes by using isolated primary pre-adipocytes (PAs) and the human adipocyte cell strain Simpson-Golabi-Behmel syndrome. In undifferentiated PAs, FABP4 expression was barely detectable and increased continuously during differentiation. The increase in FABP4 mRNA expression was accompanied by high levels of FABP4 secretion. In differentiated human adipocytes, FABP4 secretion was not abolished by blocking the Golgi-dependent secretory pathway in vitro, supporting a non-classical secretion mechanism for FABP4. However, raising intracellular Ca(2+) levels enhanced FABP4 secretion in a concentration-dependent manner.

CONCLUSION

This study shows that FABP4 is actively released from human adipocytes in vitro via a non-classical, calcium-dependent mechanism.

Assessment of small fiber neuropathy to predict future risk of type 2 diabetes

OBJECTIVE

Sudomotor dysfunction due to small fiber neuropathy can be observed very early in pre-diabetes. The aim of this study was to assess the predictive power of EZSCAN, a non invasive, quick and simple measurement of sudomotor function to identify glucose impairment.

RESEARCH DESIGN AND METHODS

The study was performed in 76 German subjects at risk of diabetes. Glucose metabolism was assessed by using, oral glucose tolerance test (OGTT) at baseline and after 2 year follow-up. Sudomotor function was evaluated by measuring hand and foot electrochemical sweat conductances to calculate a risk score.

RESULTS

At baseline, 38 patients had normal glucose tolerance (NGT), 34 had pre-diabetes (impaired fasting glucose, IFG and/or impaired glucose tolerance, IGT) and 4 had newly diagnosed type 2 diabetes. The AUC values for FPG, 2h-OGTT glucose, 1h-OGTT glucose, HbA1C and EZSCAN score to predict pre-diabetes were 0.50, 0.65, 0.64, 0.72 and 0.76, respectively. Subjects having a moderate or high EZSCAN score (>50) at baseline had a substantially increased risk for having IFG and/or IGT at follow-up visit presented by an odds ratio of 12.0 [1.4-100.5], the OR for having 1h-OGTT ≥ 8.6mmol/L at follow-up was 9.8 [1.0-92.8] and for having HbA1C ≥ 5.7% was 15.7 [1.9-131.5] compared to subjects with low EZSCAN risk.

CONCLUSIONS

This preliminary study, which must be confirmed in a larger population, shows that EZSCAN risk score is associated with diabetes progression which have implications for prevention and disease management.

Current situation of lipoprotein apheresis in Saxony

This paper summarizes the situation pertinent to treatment via lipoprotein apheresis in the federal state of Saxony, Germany in 2010. In total, 119 predominately male patients were treated in 10 centers; the majority of the patients was older than the mean age of the general population. Several risk factors were present, particularly a familial predisposition and hypertension. All patients had experienced cardiovascular events and the majority was taking statins. Patient data from the University Hospital Carl Gustav Carus in Dresden concurred with data derived from patients treated at nephrological practices. In the mean, patients attended the centers for about 6 years, the majority weekly. LDL cholesterol concentrations prior to apheresis were clearly higher than target levels; apheresis sessions decreased LDL cholesterol by 69%. Lipoprotein(a) levels could be measured in 75 patients and were effectively reduced by lipoprotein apheresis. In Saxony, 29 patients per 1 million inhabitants received lipoprotein apheresis, which is higher than the proportion of patients treated in Germany as a whole. The need for this extracorporeal treatment seems to be much greater than its current utilization. Among the patients only one homozygous patient with familial hypercholesterolemia was observed. Physicians should be actively informed about this therapeutic possibility to reduce the cardiovascular risk efficiently. The introduction of new drugs may alter the position of lipoprotein apheresis within the therapeutic spectrum.