The effect of radiofrequency electromagnetic fields (RF-EMF) on biomarkers of oxidative stress in vivo and in vitro: A protocol for a systematic review.

BACKGROUND: Oxidative stress is conjectured to be related to many diseases. Furthermore, it is hypothesized that radiofrequency fields may induce oxidative stress in various cell types and thereby compromise human and animal health. This systematic review (SR) aims to summarize and evaluate the literature related to this hypothesis. OBJECTIVES: The main objective of this SR is to evaluate the associations between the exposure to radiofrequency electromagnetic fields and oxidative stress in experimental models (in vivo and in vitro). METHODS: The SR framework has been developed following the guidelines established in the WHO Handbook for Guideline Development and the Handbook for Conducting a Literature-Based Health Assessment). We will include controlled in vivo and in vitro laboratory studies that assess the effects of an exposure to RF-EMF on valid markers for oxidative stress compared to no or sham exposure. The protocol is registered in PROSPERO. We will search the following databases: PubMed, Embase, Web of Science Core Collection, Scopus, and the EMF-Portal. The reference lists of included studies and retrieved review articles will also be manually searched. STUDY APPRAISAL AND SYNTHESIS METHOD: Data will be extracted according to a pre-defined set of forms developed in the DistillerSR online software and synthesized in a meta-analysis when studies are judged sufficiently similar to be combined. If a meta-analysis is not possible, we will describe the effects of the exposure in a narrative way. RISK OF BIAS: The risk of bias will be assessed with the NTP/OHAT risk of bias rating tool for human and animal studies. We will use GRADE to assess the certainty of the conclusions (high, moderate, low, or inadequate) regarding the association between radiofrequency electromagnetic fields and oxidative stress. FUNDING: This work was funded by the World Health Organization (WHO). REGISTRATION: The protocol was registered on the PROSPERO webpage on July 8, 2021.

Protein markers and risk of type 2 diabetes and prediabetes: a targeted proteomics approach in the KORA F4/FF4 study.

The objective of the present study was to identify proteins that contribute to pathophysiology and allow prediction of incident type 2 diabetes or incident prediabetes. We quantified 14 candidate proteins using targeted mass spectrometry in plasma samples of the prospective, population-based German KORA F4/FF4 study (6.5-year follow-up). 892 participants aged 42-81 years were selected using a case-cohort design, including 123 persons with incident type 2 diabetes and 255 persons with incident WHO-defined prediabetes. Prospective associations between protein levels and diabetes, prediabetes as well as continuous fasting and 2 h glucose, fasting insulin and insulin resistance were investigated using regression models adjusted for established risk factors. The best predictive panel of proteins on top of a non-invasive risk factor model or on top of HbA1c, age, and sex was selected. Mannan-binding lectin serine peptidase (MASP) levels were positively associated with both incident type 2 diabetes and prediabetes. Adiponectin was inversely associated with incident type 2 diabetes. MASP, adiponectin, apolipoprotein A-IV, apolipoprotein C-II, C-reactive protein, and glycosylphosphatidylinositol specific phospholipase D1 were associated with individual continuous outcomes. The combination of MASP, apolipoprotein E (apoE) and adiponectin improved diabetes prediction on top of both reference models, while prediabetes prediction was improved by MASP plus CRP on top of the HbA1c model. In conclusion, our mass spectrometric approach revealed a novel association of MASP with incident type 2 diabetes and incident prediabetes. In combination, MASP, adiponectin and apoE improved type 2 diabetes prediction beyond non-invasive risk factors or HbA1c, age and sex.

Temporal trends in cardiovascular risk factors and performance of the Framingham Risk Score and the Pooled Cohort Equations.

BACKGROUND: The Framingham Risk Score (FRS) and the Pooled Cohort Equations (PCE) are established tools for the prediction of cardiovascular disease (CVD) risk. In the Western world, decreases in incidence rates of CVD were observed over the last 30 years. Thus, we hypothesise that there are also temporal trends in the risk prediction performance of the FRS and PCE from 1990 to 2000. METHODS: We used data from n=7789 men and women aged 40-74 years from three prospective population-based cohort studies enrolled in Southern Germany in 1989/1990, 1994/1995 and 1999/2000. 10-year CVD risk was calculated by recalibrated equations of the FRS or PCE. Calibration was evaluated by percentage of overestimation and Hosmer-Lemeshow tests. Discrimination performance was assessed by receiver operating characteristic (ROC) curves and corresponding area under the curve (AUC). RESULTS: Across the three studies, we found significant temporal trends in risk factor distributions and predicted risks by both risk scores (men: 18.0%, 15.4%, 14.9%; women: 8.7%, 11.2%, 10.8%). Furthermore, also the discrimination performance evolved differently for men (AUC PCE: 76.4, 76.1, 72.8) and women (AUC PCE: 75.9, 79.5, 80.5). Both risk scores overestimated actual CVD risk. CONCLUSION: There are temporal trends in the performance of the FRS and PCE. Although the overall performance remains adequate, sex-specific trends have to be taken into account for further refinement of risk prediction models.

Association of changes in inflammation with variation in glycaemia, insulin resistance and secretion based on the KORA study.

AIMS: Subclinical systemic inflammation may contribute to the development of type 2 diabetes, but its association with early progression of glycaemic deterioration in persons without diabetes has not been fully investigated. Our primary aim was to assess longitudinal associations of changes in pro-inflammatory (leukocytes, high-sensitivity C-reactive protein (hsCRP)) and anti-inflammatory (adiponectin) markers with changes in markers that assessed glycaemia, insulin resistance, and secretion (HbA1c , HOMA-IR, and HOMA-ß). Furthermore, we aimed to directly compare longitudinal with cross-sectional associations. MATERIALS AND METHODS: This study includes 819 initially nondiabetic individuals with repeated measurements from the Cooperative Health Research in the Region of Augsburg (KORA) S4/F4 cohort study (median follow-up: 7.1 years). Longitudinal and cross-sectional associations were simultaneously examined using linear mixed growth models. Changes in markers of inflammation were used as independent and changes in markers of glycaemia/insulin resistance/insulin secretion as dependent variables. Models were adjusted for age, sex, major lifestyle and metabolic risk factors for diabetes using time-varying variables in the final model. RESULTS: Changes of leukocyte count were positively associated with changes in HbA1c and HOMA-ß while changes in adiponectin were inversely associated with changes in HbA1c . All examined cross-sectional associations were statistically significant; they were generally stronger and mostly directionally consistent to the longitudinal association estimates. CONCLUSIONS: Adverse changes in low-grade systemic inflammation go along with glycaemic deterioration and increased insulin secretion independently of changes in other risk factors, suggesting that low-grade inflammation may contribute to the development of hyperglycaemia and a compensatory increase in insulin secretion.

Ultra-sensitive troponin I is an independent predictor of incident coronary heart disease in the general population.

Troponins are sensitive markers of myocardial injury and predictive of cardiovascular events, but conventional assays fail to detect slightly elevated troponins in a considerable proportion of the general population. Using a novel ultrasensitive assay, we explored the relationship of troponin levels with the incidence of coronary heart disease (CHD) in a case-cohort sample (mean age 52.5 ± 0.2 years, 51.5% women) comprising 803 CHD cases and 1942 non-cases. Ultrasensitive troponin I was detectable in 99.9% of available case-cohort samples. In an age- and sex-adjusted model, individuals in the highest quartile of the troponin distribution had a more than threefold increased risk for CHD events compared to those in the bottom quartile [hazard ratio, HR, 3.11; 95% confidence interval (CI) 2.15-4.49]. In a model adjusting for cardiovascular risk factors including C-reactive protein, cystatin C and N-terminal pro brain natriuretic peptide, individuals in the highest troponin I quartile still showed a hazard ratio of 2.58 (95% CI 1.66-4.00) for incident CHD as compared to those in the lowest quartile. Ultrasensitive troponin I was detectable in almost all individuals of a study sample reflecting middle-aged to elderly European general population. Ultrasensitive troponin concentrations exhibit an independent, graded, positive relation with incident CHD.

Circulating Levels of Interleukin 1-Receptor Antagonist and Risk of Cardiovascular Disease: Meta-Analysis of Six Population-Based Cohorts.

OBJECTIVE: Interleukin (IL)-1ß represents a key cytokine in the development of cardiovascular disease (CVD). IL-1ß is counter-regulated by IL-1 receptor antagonist (IL-1RA), an endogenous inhibitor. This study aimed to identify population-based studies on circulating IL-1RA and incident CVD in a systematic review, estimate the association between IL-1RA and incident CVD in a meta-analysis, and to test whether the association between IL-1RA and incident CVD is explained by other inflammation-related biomarkers in the MONICA/KORA Augsburg case-cohort study (Multinational Monitoring of Trends and Determinants in Cardiovascular Disease/Cooperative Health Research in the Region of Augsburg). APPROACH AND RESULTS: We performed a systematic literature search and identified 5 cohort studies on IL-1RA and incident CVD in addition to the MONICA/KORA Augsburg case-cohort study for a meta-analysis based on a total of 1855 CVD cases and 18 745 noncases with follow-up times between 5 and 16 years. The pooled standardized hazard ratio (95% confidence interval) for incident CVD was 1.11 (1.06-1.17) after adjustment for age, sex, anthropometric, metabolic, and lifestyle factors (P<0.0001). There was no heterogeneity in effect sizes (I2=0%; P=0.88). More detailed analyses in the MONICA/KORA study showed that the excess risk for CVD was attenuated by ≥10% after additional separate adjustment for serum levels of high-sensitivity C-reactive protein, IL-6, myeloperoxidase, soluble E-selectin, or soluble intercellular adhesion molecule-1. CONCLUSIONS: Serum IL-1RA levels were positively associated with risk of CVD after adjustment for multiple confounders in a meta-analysis of 6 population-based cohorts. This association may at least partially reflect a response to triggers inducing subclinical inflammation, oxidative stress, and endothelial activation.

Symmetric dimethylarginine, high-density lipoproteins and cardiovascular disease.

AIMS: The vascular effects of high-density lipoproteins (HDL) differ under certain clinical conditions. The composition of HDL is modified in patients with chronic kidney disease (CKD). As a consequence, uremic HDL induces endothelial dysfunction. We have previously shown that accumulation of symmetric dimethylarginine (SDMA) in HDL causes these adverse effects of HDL in CKD. The aim of the study is to determine the impact of the accumulation of SDMA on the association between HDL and mortality. METHODS AND RESULTS: Mortality, renal function, serum SDMA and HDL-cholesterol (HDL-C) were assessed in the LURIC study including 3310 subjects undergoing coronary angiography. All-cause mortality was 30.0% during median follow-up of 9.9 years. Serum SDMA levels significantly predicted all-cause and cardiovascular mortality, and were significantly correlated with SDMA accumulation in HDL. Notably, higher serum SDMA was independently associated with lower cholesterol efflux (P = 0.004) as a measure of HDL functionality. In subjects with low SDMA levels, higher HDL-C was associated with significantly lower mortality. In contrast, in subjects with high SDMA, HDL-C was associated with higher mortality. These findings were confirmed in 1424 participants of the MONICA/KORA S3 cohort. Of note, we derived an algorithm allowing for calculation of biologically effective HDL-C' based on measured HDL-C and SDMA. We corroborated these clinical findings with invitro evidence showing that SDMA accumulation abolishes the anti-inflammatory and regenerative properties of HDL. CONCLUSION: The data identify SDMA as a marker of HDL dysfunction. These findings highlight on the pivotal role of SDMA accumulation in HDL as a mediator of pre-mature cardiovascular disease in patients with CKD.

ANGPTL8 (Betatrophin) is Expressed in Visceral Adipose Tissue and Relates to Human Hepatic Steatosis in Two Independent Clinical Collectives.

Angiopoietin-like protein 8 (ANGPTL8)/betatrophin expression in visceral adipose tissue and associations with circulating fatty acid profile have not yet been investigated.Forty subjects were included in a cross-sectional study, 57 in a dietary weight reduction intervention. Circulating Angiopoietin-like protein 8/betatrophin was measured in all subjects. Liver and adipose tissue were sampled and plasma fatty acids and tissue Angiopoietin-like protein 8/betatrophin expression were evaluated in the cross-sectional study. In the intervention study oral glucose testing and liver magnetic resonance scanning at baseline and after 6 months were performed. Angiopoietin-like protein 8/betatrophin mRNA was increased in visceral compared to subcutaneous adipose tissue (p<0.001). Circulating ANGPTL8/betatrophin correlated with liver steatosis (r=0.42, p=0.047), triacylglycerols (r=0.34, p=0.046), saturated (r=0.43, p=0.022), monounsaturated (r=0.51, p=0.007), and polyunsaturated fatty acids (r=-0.53, p=0.004). In the intervention study, baseline Angiopoietin-like protein 8/betatrophin correlated with age (r=0.32, p=0.010) and triacylglycerols (r=0.30, p=0.02) and was increased with hepatic steatosis (p=0.033). Weight loss reduced liver fat by 45% and circulating Angiopoietin-like protein 8/betatrophin by 11% (288±17 vs. 258±17 pg/ml; p=0.015). Angiopoietin-like protein 8/betatrophin is related to liver steatosis, while visceral adipose tissue represents an additional site of expression in humans.

Predicting glycated hemoglobin levels in the non-diabetic general population: Development and validation of the DIRECT-DETECT prediction model - a DIRECT study.

AIMS/HYPOTHESIS: To develop a prediction model that can predict HbA1c levels after six years in the non-diabetic general population, including previously used readily available predictors. METHODS: Data from 5,762 initially non-diabetic subjects from three population-based cohorts (Hoorn Study, Inter99, KORA S4/F4) were combined to predict HbA1c levels at six year follow-up. Using backward selection, age, BMI, waist circumference, use of anti-hypertensive medication, current smoking and parental history of diabetes remained in sex-specific linear regression models. To minimize overfitting of coefficients, we performed internal validation using bootstrapping techniques. Explained variance, discrimination and calibration were assessed using R2, classification tables (comparing highest/lowest 50% HbA1c levels) and calibration graphs. The model was externally validated in 2,765 non-diabetic subjects of the population-based cohort METSIM. RESULTS: At baseline, mean HbA1c level was 5.6% (38 mmol/mol). After a mean follow-up of six years, mean HbA1c level was 5.7% (39 mmol/mol). Calibration graphs showed that predicted HbA1c levels were somewhat underestimated in the Inter99 cohort and overestimated in the Hoorn and KORA cohorts, indicating that the model's intercept should be adjusted for each cohort to improve predictions. Sensitivity and specificity (95% CI) were 55.7% (53.9, 57.5) and 56.9% (55.1, 58.7) respectively, for women, and 54.6% (52.7, 56.5) and 54.3% (52.4, 56.2) for men. External validation showed similar performance in the METSIM cohort. CONCLUSIONS/INTERPRETATION: In the non-diabetic population, our DIRECT-DETECT prediction model, including readily available predictors, has a relatively low explained variance and moderate discriminative performance, but can help to distinguish between future highest and lowest HbA1c levels. Absolute HbA1c values are cohort-dependent.

Peptide serum markers in islet autoantibody-positive children.

AIMS/HYPOTHESIS: We sought to identify minimal sets of serum peptide signatures as markers for islet autoimmunity and predictors of progression rates to clinical type 1 diabetes in a case-control study. METHODS: A double cross-validation approach was applied to first prioritise peptides from a shotgun proteomic approach in 45 islet autoantibody-positive and -negative children from the BABYDIAB/BABYDIET birth cohorts. Targeted proteomics for 82 discriminating peptides were then applied to samples from another 140 children from these cohorts. RESULTS: A total of 41 peptides (26 proteins) enriched for the functional category lipid metabolism were significantly different between islet autoantibody-positive and autoantibody-negative children. Two peptides (from apolipoprotein M and apolipoprotein C-IV) were sufficient to discriminate autoantibody-positive from autoantibody-negative children. Hepatocyte growth factor activator, complement factor H, ceruloplasmin and age predicted progression time to type 1 diabetes with a significant improvement compared with age alone. CONCLUSION/INTERPRETATION: Distinct peptide signatures indicate islet autoimmunity prior to the clinical manifestation of type 1 diabetes and enable refined staging of the presymptomatic disease period.

Increased lipogenesis in spite of upregulated hepatic 5'AMP-activated protein kinase in human non-alcoholic fatty liver.

AIMS: Molecular adaptations in human non-alcoholic fatty liver disease (NAFLD) are incompletely understood. This study investigated the main gene categories related to hepatic de novo lipogenesis and lipid oxidation capacity. METHODS: Liver specimens of 48 subjects were histologically classified according to steatosis severity. In-depth analyses were undertaken using real-time polymerase chain reaction, immunoblotting, and immunohistochemistry. Lipid profiles were analyzed by gas chromatography/flame ionization detection, and effects of key fatty acids were studied in primary human hepatocytes. RESULTS: Real-time polymerase chain reaction, immunoblotting, and immunohistochemistry indicated 5'AMP-activated protein kinase (AMPK) to be increased with steatosis score ≥ 2 (all P < 0.05), including various markers of de novo lipogenesis and lipid degradation (all P < 0.05). Regarding endoplasmic reticulum stress, X-Box binding protein-1 (XBP1) was upregulated in steatosis score ≥ 2 (P = 0.029) and correlated with plasma palmitate (r = 0.34; P = 0.035). Palmitate incubation of primary human hepatocytes increased XBP1 and downstream stearoyl CoA desaturase-1 mRNA expression (both P < 0.05). Moreover, plasma and liver tissue exposed a NAFLD-related lipid profile with reduced polyunsaturated/saturated fatty acid ratio, increased palmitate and palmitoleate, and elevated lipogenesis and desaturation indices with steatosis score ≥ 2 (all P < 0.05). CONCLUSION: In humans with advanced fatty liver disease, hepatic AMPK protein is upregulated, potentially in a compensatory manner. Moreover, pathways of lipid synthesis and degradation are co-activated in subjects with advanced steatosis. Palmitate may drive lipogenesis by activating XBP1-mediated endoplasmic reticulum stress and represent a target for future dietary or pharmacological intervention.

Recalibration of the ACC/AHA Risk Score in Two Population-Based German Cohorts.

BACKGROUND: The 2013 ACC/AHA guidelines introduced an algorithm for risk assessment of atherosclerotic cardiovascular disease (ASCVD) within 10 years. In Germany, risk assessment with the ESC SCORE is limited to cardiovascular mortality. Applicability of the novel ACC/AHA risk score to the German population has not yet been assessed. We therefore sought to recalibrate and evaluate the ACC/AHA risk score in two German cohorts and to compare it to the ESC SCORE. METHODS: We studied 5,238 participants from the KORA surveys S3 (1994-1995) and S4 (1999-2001) and 4,208 subjects from the Heinz Nixdorf Recall (HNR) Study (2000-2003). There were 383 (7.3%) and 271 (6.4%) first non-fatal or fatal ASCVD events within 10 years in KORA and in HNR, respectively. Risk scores were evaluated in terms of calibration and discrimination performance. RESULTS: The original ACC/AHA risk score overestimated 10-year ASCVD rates by 37% in KORA and 66% in HNR. After recalibration, miscalibration diminished to 8% underestimation in KORA and 12% overestimation in HNR. Discrimination performance of the ACC/AHA risk score was not affected by the recalibration (KORA: C = 0.78, HNR: C = 0.74). The ESC SCORE overestimated by 5% in KORA and by 85% in HNR. The corresponding C-statistic was 0.82 in KORA and 0.76 in HNR. CONCLUSIONS: The recalibrated ACC/AHA risk score showed strongly improved calibration compared to the original ACC/AHA risk score. Predicting only cardiovascular mortality, discrimination performance of the commonly used ESC SCORE remained somewhat superior to the ACC/AHA risk score. Nevertheless, the recalibrated ACC/AHA risk score may provide a meaningful tool for estimating 10-year risk of fatal and non-fatal cardiovascular disease in Germany.

The cardiovascular markers copeptin and high-sensitive C-reactive protein decrease following specific therapy for primary aldosteronism.

CONTEXT: Copeptin and high-sensitive C-reactive protein (hsCRP) are biomarkers associated with increased mortality in patients with cardiovascular and cerebrovascular disease as well as in the general population. No data exist regarding these markers in patients with primary aldosteronism. OBJECTIVE: To evaluate copeptin and hsCRP levels as cardiovascular risk markers in primary aldosteronism patients. METHODS: A total of 113 primary aldosteronism patients (64% male) from two centers of the prospective German Conn's Registry were identified, for whom a full data set and blood samples at baseline and follow-up (14 ±â€Š3.4 months) after initiation of specific primary aldosteronism treatment were available. These cases were matched 1 : 3 (n = 339) for sex, renal function, BMI, age and SBP with participants from the Cooperative Health Research in the Region of Augsburg F4 survey. Copeptin and hsCRP were determined by sandwich fluoroimmunoassay. RESULTS: HsCRP was significantly higher in primary aldosteronism patients at baseline compared with matched controls. Following specific therapy, hsCRP and copeptin decreased significantly in primary aldosteronism patients [median (25th and 75th percentile): 1.6 (0.8, 3.4) to 1.2 (0.6, 2.1) mg/l, P < 0.001; 7.8 (4.6, 13.5) to 5.0 (3.1, 8.9) pmol/l, P < 0.001, respectively]. Men had higher hsCRP and copeptin levels at baseline and follow-up compared with women. The combination of sex, hypokalemia, lateralization index and blood pressure were the best predictors of outcome. However, copeptin and hsCRP had no predictive value despite the association of lower copeptin levels with better outcome regarding cure of primary aldosteronism. CONCLUSION: Copeptin and hsCRP levels decrease following specific primary aldosteronism therapy reflecting successful cardiovascular risk reduction. However, they are no independent predictors regarding cure of primary aldosteronism.

Comparison of different measures of obesity in their association with health-related quality of life in older adults - results from the KORA-Age study.

OBJECTIVE: As ageing is associated with changes in body composition, BMI may not be the appropriate obesity measure for older adults. To date, little is known about associations between obesity measures and health-related quality of life (HRQoL). Thus, we aimed to compare different obesity measures in their association with HRQoL and self-rated physical constitution (SRPC) in older adults. DESIGN: Seven obesity measures (BMI, waist circumference (WC), waist-to-hip ratio, waist-to-height ratio, fat mass percentage based on bioelectrical impedance analysis, hypertriglyceridaemic waist (HTGW) and sarcopenic obesity) were assessed at baseline in 2009. HRQoL, using the EQ-5D questionnaire, and SRPC, using one single question, were collected at baseline and at the 3-year follow-up in 2012. Linear and logistic regression analyses were used to examine the associations between the obesity measures and both outcomes. Model comparisons were conducted by area under the receiver-operating characteristic curve, R 2, Akaike and Schwarz Bayesian information criteria. SETTING: KORA-Age study in Southern Germany (2009-2012). SUBJECTS: Older adults (n 883; aged ≥65 years). RESULTS: Nearly all obesity measures were significantly inversely associated with both outcomes in cross-sectional analyses. Concerning HRQoL, the WC model explained most of the variance and had the best model adaption, followed by the BMI model. Regarding SRPC, the HTGW and BMI models were best as rated by model quality criteria, followed closely by the WC model. Longitudinal analyses showed no significant associations. CONCLUSIONS: These results suggest that, with regard to HRQoL/SRPC, simple anthropometric measures are sufficient to determine obesity in older adults in medical practice.

MASP1, THBS1, GPLD1 and ApoA-IV are novel biomarkers associated with prediabetes: the KORA F4 study.

AIMS/HYPOTHESIS: Individuals at a high risk of type 2 diabetes demonstrate moderate impairments in glucose metabolism years before the clinical manifestation of type 2 diabetes, a state called 'prediabetes'. In order to elucidate the pathophysiological processes leading to type 2 diabetes, we aimed to identify protein biomarkers associated with prediabetes. METHODS: In a proteomics study, we used targeted selected reaction monitoring (SRM)-MS to quantify 23 candidate proteins in the plasma of 439 randomly selected men and women aged 47-76 years from the population-based German KORA F4 study. Cross-sectional associations of protein levels with prediabetes (impaired fasting glucose and/or impaired glucose tolerance), type 2 diabetes, glucose levels in both the fasting state and 2 h after an OGTT, fasting insulin and insulin resistance were investigated using regression models adjusted for technical covariables, age, sex, BMI, smoking, alcohol intake, physical inactivity, actual hypertension, triacylglycerol levels, total cholesterol/HDL-cholesterol ratio, and high-sensitivity C-reactive protein levels. RESULTS: Mannan-binding lectin serine peptidase 1 (MASP1; OR per SD 1.77 [95% CI 1.26, 2.47]), thrombospondin 1 (THBS1; OR per SD 1.55 [95% CI 1.16, 2.07]) and glycosylphosphatidylinositol-specific phospholipase D1 (GPLD1; OR per SD 1.40 [95% CI 1.01, 1.94]) were positively associated with prediabetes, and apolipoprotein A-IV (ApoA-IV; OR per SD 0.75 [95% CI 0.56, 1.00]) was inversely associated with prediabetes. MASP1 was positively associated with fasting and 2 h glucose levels. ApoA-IV was inversely and THBS1 was positively associated with 2 h glucose levels. MASP1 associations with prediabetes and fasting glucose resisted Bonferroni correction. Type 2 diabetes associations were partly influenced by glucose-lowering medication. CONCLUSIONS/INTERPRETATION: We discovered novel and independent associations of prediabetes and related traits with MASP1, and some evidence for associations with THBS1, GPLD1 and ApoA-IV, suggesting a role for these proteins in the pathophysiology of type 2 diabetes.

High-Fat Diet During Mouse Pregnancy and Lactation Targets GIP-Regulated Metabolic Pathways in Adult Male Offspring.

Maternal obesity is a worldwide problem associated with increased risk of metabolic diseases in the offspring. Genetic deletion of the gastric inhibitory polypeptide (GIP) receptor (GIPR) prevents high-fat diet (HFD)-induced obesity in mice due to specific changes in energy and fat cell metabolism. We investigated whether GIP-associated pathways may be targeted by fetal programming and mimicked the situation by exposing pregnant mice to control or HFD during pregnancy (intrauterine [IU]) and lactation (L). Male wild-type (WT) and Gipr(-/-) offspring received control chow until 25 weeks of age followed by 20 weeks of HFD. Gipr(-/-) offspring of mice exposed to HFD during IU/L became insulin resistant and obese and exhibited increased adipose tissue inflammation and decreased peripheral tissue substrate utilization after being reintroduced to HFD, similar to WT mice on regular chow during IU/L. They showed decreased hypothalamic insulin sensitivity compared with Gipr(-/-) mice on control diet during IU/L. DNA methylation analysis revealed increased methylation of CpG dinucleotides and differential transcription factor binding of promoter regions of genes involved in lipid oxidation in the muscle of Gipr(-/-) offspring on HFD during IU/L, which were inversely correlated with gene expression levels. Our data identify GIP-regulated metabolic pathways that are targeted by fetal programming.

Serum amyloid A: high-density lipoproteins interaction and cardiovascular risk.

AIMS: High-density lipoproteins (HDLs) are considered as anti-atherogenic. Recent experimental findings suggest that their biological properties can be modified in certain clinical conditions by accumulation of serum amyloid A (SAA). The effect of SAA on the association between HDL-cholesterol (HDL-C) and cardiovascular outcome remains unknown. METHODS AND RESULTS: We examined the association of SAA and HDL-C with mortality in the Ludwigshafen Risk and Cardiovascular Health (LURIC) study, which included 3310 patients undergoing coronary angiography. To validate our findings, we analysed 1255 participants of the German Diabetes and Dialysis study (4D) and 4027 participants of the Cooperative Health Research in the Region of Augsburg (KORA) S4 study. In LURIC, SAA concentrations predicted all-cause and cardiovascular mortality. In patients with low SAA, higher HDL-C was associated with lower all-cause and cardiovascular mortality. In contrast, in patients with high SAA, higher HDL-C was associated with increased all-cause and cardiovascular mortality, indicating that SAA indeed modifies the beneficial properties of HDL. We complemented these clinical observations by in vitro experiments, in which SAA impaired vascular functions of HDL. We further derived a formula for the simple calculation of the amount of biologically 'effective' HDL-C based on measured HDL-C and SAA from the LURIC study. In 4D and KORA S4 studies, we found that measured HDL-C was not associated with clinical outcomes, whereas calculated 'effective' HDL-C significantly predicted better outcome. CONCLUSION: The acute-phase protein SAA modifies the biological effects of HDL-C in several clinical conditions. The concomitant measurement of SAA is a simple, useful, and clinically applicable surrogate for the vascular functionality of HDL.

Association of subclinical inflammation with deterioration of glycaemia before the diagnosis of type 2 diabetes: the KORA S4/F4 study.

AIMS/HYPOTHESIS: The role of biomarkers of subclinical inflammation in the early deterioration of glycaemia before type 2 diabetes is largely unknown. We hypothesised that increased levels of circulating proinflammatory biomarkers and decreased circulating adiponectin would be associated with 7 year increases of HbA(1c) in non-diabetic individuals. METHODS: This study was based on individuals who participated in the prospective Cooperative Health Research in the Region of Augsburg (KORA) S4 survey (1999-2001) and the 7 year follow-up KORA F4 (2006-2008) survey. Individuals with type 2 diabetes at baseline or with a diagnosis of diabetes in the period between both surveys were excluded, which left a sample of 850 men and women. Multivariable linear regression analyses were performed to assess associations among baseline values of leucocyte count and levels of acute-phase proteins (high-sensitivity C-reactive protein [hsCRP], serum amyloid A [SAA] and fibrinogen), IL-6 and adiponectin with changes in HbA1c between baseline and follow-up. RESULTS: A high leucocyte count and high hsCRP, SAA and IL-6 levels were positively associated with changes in HbA(1c) after adjusting for age, sex, lifestyle factors and baseline HbA(1c). In contrast, the adiponectin level was inversely associated with changes in HbA(1c) (p value between <0.0001 and 0.020). The associations of leucocyte count and levels of hsCRP and SAA with HbA(1c) changes remained significant after additional adjustment for waist circumference and circulating lipids at baseline and for the 7 year change in waist circumference (p value between 0.004 and 0.045). CONCLUSIONS/INTERPRETATION: An elevated leucocyte count and elevated hsCRP and SAA were associated with early deterioration of glycaemia before the diagnosis of type 2 diabetes. These associations were largely independent of baseline abdominal adiposity and increases in waist circumference.

Modulation of insulin degrading enzyme activity and liver cell proliferation.

Diabetes mellitus type 2 (T2DM), insulin therapy, and hyperinsulinemia are independent risk factors of liver cancer. Recently, the use of a novel inhibitor of insulin degrading enzyme (IDE) was proposed as a new therapeutic strategy in T2DM. However, IDE inhibition might stimulate liver cell proliferation via increased intracellular insulin concentration. The aim of this study was to characterize effects of inhibition of IDE activity in HepG2 hepatoma cells and to analyze liver specific expression of IDE in subjects with T2DM. HepG2 cells were treated with 10 nM insulin for 24 h with or without inhibition of IDE activity using IDE RNAi, and cell transcriptome and proliferation rate were analyzed. Human liver samples (n = 22) were used for the gene expression profiling by microarrays. In HepG2 cells, IDE knockdown changed expression of genes involved in cell cycle and apoptosis pathways. Proliferation rate was lower in IDE knockdown cells than in controls. Microarray analysis revealed the decrease of hepatic IDE expression in subjects with T2DM accompanied by the downregulation of the p53-dependent genes FAS and CCNG2, but not by the upregulation of proliferation markers MKI67, MCM2 and PCNA. Similar results were found in the liver microarray dataset from GEO Profiles database. In conclusion, IDE expression is decreased in liver of subjects with T2DM which is accompanied by the dysregulation of p53 pathway. Prolonged use of IDE inhibitors for T2DM treatment should be carefully tested in animal studies regarding its potential effect on hepatic tumorigenesis.

Prospective association of vitamin D with frailty status and all-cause mortality in older adults: Results from the KORA-Age Study.

OBJECTIVE: To assess the prospective association of serum 25-hydroxyvitamin D [25(OH)D] levels with frailty status and all-cause mortality in a cohort of community-dwelling participants of the population-based KORA [Cooperative Health Research in the Region of Augsburg]-Age Study. METHODS: 727 non-frail participants, aged ≥65years, with 25(OH)D measurement at baseline in 2009, were followed for 2.9±0.1years. Participants were classified as pre-frail or frail if they met 1-2 or ≥3, respectively, of the following five criteria: weight loss, exhaustion, physical inactivity, low walking speed, weakness. The association between 25(OH)D and mortality was assessed in 954 participants. Multivariable adjusted logistic regression models were calculated for each outcome. RESULTS: The incidence of pre-frailty and frailty was 21.2% and 3.9% respectively. After multivariable adjustment, participants with very low 25(OH)D levels (<15ng/ml vs. ≥30ng/ml) had a significantly higher odds for pre-frailty (OR=2.43 [95% CI: 1.17-5.03]) and pre-frailty/frailty combined (OR=2.53 [95% CI: 1.23-5.22]), but not for frailty alone (OR=2.63 [95% CI: 0.39-17.67]). The association between 25(OH)D and mortality (OR=3.39 [95% CI: 1.08-10.65]) was partly mediated by frailty status. CONCLUSION: Very low 25(OH)D levels were independently associated with incident pre-frailty, pre-frailty/frailty combined and all-cause mortality.