Incidence of Type 2 diabetes in the elderly German population and the effect of clinical and lifestyle risk factors: KORA S4/F4 cohort study

Dose-response association between OGTT and adverse perinatal outcomes after IVF treatment: A cohort study based on a twin population

BACKGROUND

Investigate the association between Oral Glucose Tolerance Test (OGTT) after in vitro fertilization (IVF) treatment and adverse maternal and neonatal outcomes in twin pregnancies.

METHODS

This retrospective study encompassed 2,541 twin pregnancies conceived through IVF treatment. Adverse maternal and neonatal outcomes were compared across different subgroups based on individual and combined OGTT classifications. A Spearman correlation regression model examined associations between OGTT levels at different time points and parameters such as gestational age, birth weight, and length. Subsequently, a Logistic regression model with restricted cubic splines (RCS) explored the relationships between OGTT levels at different time points and adverse pregnancy outcomes. Ultimately, nine types of machine learning models were developed using OGTT glucose values at different times to predict the risk of adverse pregnancy outcomes.

RESULTS

In subgroup analysis based on individual OGTT diagnosis, three time points were examined: fasting glucose (OGTT0), 1-hour post-glucose (OGTT1), and 2-hour post-glucose (OGTT2). OGTT0 ≥ 5.1 mmol/L was significantly associated with increased risks of ICP and neonatal hypoglycemia (p = 0.031; p = 0.022). OGTT1 ≥ 10 mmol/L correlated with higher risks of ICP and neonatal hyperbilirubinemia (p = 0.001; p = 0.002). OGTT2 ≥ 8.5 mmol/L was also linked to neonatal hyperbilirubinemia (p < 0.001). In combined impaired OGTT subgroups, the impaired fasting glucose (IFG) group had a higher incidence of neonatal hypoglycemia than the impaired glucose tolerance (IGT) group and IFG & IGT group, but a lower risk of neonatal hyperbilirubinemia. OGTT2 was negatively correlated with gestational age at delivery (β = - 0.08, p = 0.018), and both OGTT1 and OGTT2 were negatively correlated with neonatal birth weight (β = - 10.54, p = 0.008; β = - 15.04, p < 0.001), as well as OGTT2 with birth length (β = - 0.16, p = 0.009). The RCS logistic regression model indicated that the increase OGTT values was associated with the ICP risk, and the relationship between OGTT2 and neonatal hyperbilirubinemia was U-shaped. Among the various machine learning models predicting adverse outcomes, RandomForest exhibited superior performance.

CONCLUSION

OGTT values in twin pregnancies under IVF treatment are closely linked to adverse maternal and neonatal outcomes, with post-load glucose levels potentially serving as an early biomarker for identifying poorer outcomes. The inflection points in the RCS suggest a new indication point for the association between OGTT and adverse pregnancy outcomes in twin pregnancies conceived through IVF.

Phenotype-based clusters, inflammation and cardiometabolic complications in older people before the diagnosis of type 2 diabetes: KORA F4/FF4 cohort study

BACKGROUND

Using a data-driven approach, six clusters with different risk profiles and burden of complications were recently identified in middle-aged people before the diagnosis of type 2 diabetes (T2D). We aimed to investigate whether these clusters could be generalised to older people and if subclinical inflammation was related to their cardiometabolic risk profiles.

METHODS

We assigned 843 participants of the KORA F4 study aged 61-82 years without T2D to the six previously defined phenotype-based clusters. Based on 73 biomarkers of subclinical inflammation, we derived an inflammation-related score ("inflammatory load") using principal component analysis to assess subclinical inflammation. Risk factors, inflammatory load as well as prevalence and incidence of (pre)diabetes-related complications were compared between the clusters using pairwise comparisons and regression analyses.

RESULTS

Clusters 1 and 2 had the lowest cardiometabolic risk, whereas clusters 5 and 6 the highest. T2D risk was highest in clusters 3, 4, 5, and 6 compared with the low-risk cluster 2 (age- and sex-adjusted ORs between 3.6 and 34.0). In cross-sectional analyses, there were significant between-cluster differences in chronic kidney disease (CKD), distal sensorimotor polyneuropathy (DSPN) and cardiovascular disease (all p < 0.045). In prospective analyses (mean follow-up time 6.5-8.3 years), clusters differed significantly in CKD and DSPN incidence, but not in incident CVD or all-cause mortality. The inflammatory load was highest in the high-risk cluster 5 and lowest in cluster 2. Adjustment for the inflammatory load had only a minor impact on the aforementioned differences in outcomes between clusters.

CONCLUSIONS

Our findings extend the knowledge about the previously identified six phenotype-based clusters in older people without T2D. Differences between clusters were more pronounced for T2D risk than for prevalent or incident (pre)diabetes-related complications and absent for mortality. The high cardiometabolic risk corresponded to the high inflammatory load in cluster 5 but not to the lower inflammatory load of high-risk clusters 3 and 6.

Interpretable multimodal machine learning (IMML) framework reveals pathological signatures of distal sensorimotor polyneuropathy

BACKGROUND

Distal sensorimotor polyneuropathy (DSPN) is a common neurological disorder in elderly adults and people with obesity, prediabetes and diabetes and is associated with high morbidity and premature mortality. DSPN is a multifactorial disease and not fully understood yet.

METHODS

Here, we developed the Interpretable Multimodal Machine Learning (IMML) framework for predicting DSPN prevalence and incidence based on sparse multimodal data. Exploiting IMMLs interpretability further empowered biomarker identification. We leveraged the population-based KORA F4/FF4 cohort including 1091 participants and their deep multimodal characterisation, i.e. clinical data, genomics, methylomics, transcriptomics, proteomics, inflammatory proteins and metabolomics.

RESULTS

Clinical data alone is sufficient to stratify individuals with and without DSPN (AUROC = 0.752), whilst predicting DSPN incidence 6.5 ± 0.2 years later strongly benefits from clinical data complemented with two or more molecular modalities (improved ΔAUROC > 0.1, achieved AUROC of 0.714). Important and interpretable features of incident DSPN prediction include up-regulation of proinflammatory cytokines, down-regulation of SUMOylation pathway and essential fatty acids, thus yielding novel insights in the disease pathophysiology.

CONCLUSIONS

These may become biomarkers for incident DSPN, guide prevention strategies and serve as proof of concept for the utility of IMML in studying complex diseases.

Loss of atrial natriuretic peptide signaling causes insulin resistance, mitochondrial dysfunction, and low endurance capacity

Type 2 diabetes (T2D) and obesity are strongly associated with low natriuretic peptide (NP) plasma levels and a down-regulation of NP guanylyl cyclase receptor-A (GCA) in skeletal muscle and adipose tissue. However, no study has so far provided evidence for a causal link between atrial NP (ANP)/GCA deficiency and T2D pathogenesis. Here, we show that both systemic and skeletal muscle ANP/GCA deficiencies in mice promote metabolic disturbances and prediabetes. Skeletal muscle insulin resistance is further associated with altered mitochondrial function and impaired endurance running capacity. ANP/GCA-deficient mice exhibit increased proton leak and reduced content of mitochondrial oxidative phosphorylation proteins. We further show that GCA is related to several metabolic traits in T2D and positively correlates with markers of oxidative capacity in human skeletal muscle. Together, these results indicate that ANP/GCA signaling controls muscle mitochondrial integrity and oxidative capacity in vivo and plays a causal role in the development of prediabetes.

Differential associations between selenoprotein P and distal sensorimotor polyneuropathy in people with and without diabetes: KORA F4/FF4 study

BACKGROUND

Oxidative stress is a risk factor for distal sensorimotor polyneuropathy (DSPN). Selenoprotein P is a protein with antioxidant properties but has not been investigated in the context of DSPN. This study aimed to assess the associations between selenoprotein P and DSPN in people without and with type 2 diabetes (T2D).

METHODS

Cross-sectional and prospective analyses were based on 1053 (including 217 with T2D) and 513 participants (including 79 with T2D), respectively, aged 61-82 years from the population-based KORA F4 survey. DSPN at baseline (KORA F4) and in the follow-up survey KORA FF4 was defined based on the Michigan Neuropathy Screening Instrument. Serum levels of full-length selenoprotein P were quantified by ELISA. Associations between selenoprotein P and prevalent or incident DSPN were estimated using logistic regression analysis adjusting for multiple confounders.

RESULTS

Selenoprotein P levels were not associated with prevalent DSPN in the total sample. However, there was a significant interaction by diabetes status. Higher levels of selenoprotein P were associated with lower odds of prevalent DSPN in individuals without T2D (fully adjusted model: OR 0.825 [95 % CI 0.682, 0.998], p = 0.0476), but not in those with T2D (OR [95 % CI] 1.098 [0.829, 1.454], p = 0.5132; pinteraction = 0.0488). Selenoprotein P levels were not associated with incident DSPN over a follow-up of 6.5 years.

CONCLUSION

In individuals without T2D from the older general population, lower selenoprotein P levels were associated with a higher prevalence of DSPN. Whether the antioxidant properties of selenoprotein P are responsible for the observed associations remains to be elucidated in future research.

Knowledge and attitude on the role of lifestyle modifications in the management of diabetes in Jeddah, Saudi Arabia

BACKGROUND

Public knowledge about the role of lifestyle in managing type two diabetes (T2D) is an essential preventive strategy. Despite efforts in public awareness, the prevalence continues to rise, with the majority relying on the availability of effective therapeutics, underestimating the role of healthy lifestyle changes. This study aims to assess public awareness of the impact of lifestyle modification in managing T2D in a major metropolitan city in Saudi Arabia, which will help inform the health management authority in the country on the level of public awareness and advise on the development of educational programs.

METHODS

An observational cross-sectional survey study comprising 16 knowledge and 6 attitude questions was conducted among the population over 18 years old using online survey. After validation, the online self-developed questionnaire was distributed through social media.

RESULTS

The knowledge and attitude scores were similar between males and females. Participants with a family member or friend with T2D demonstrated higher knowledge scores. However, the attitude scores did not differ significantly based on family or friend relationships.

CONCLUSION

The knowledge and attitude on the role of lifestyle modifications in preventing and managing T2D is moderate, implying an opportunity for innovative strategies to raise public knowledge and attitude.

Prediction of Myocardial Infarction Using a Combined Generative Adversarial Network Model and Feature-Enhanced Loss Function

Accurate risk prediction for myocardial infarction (MI) is crucial for preventive strategies, given its significant impact on global mortality and morbidity. Here, we propose a novel deep-learning approach to enhance the prediction of incident MI cases by incorporating metabolomics alongside clinical risk factors. We utilized data from the KORA cohort, including the baseline S4 and follow-up F4 studies, consisting of 1454 participants without prior history of MI. The dataset comprised 19 clinical variables and 363 metabolites. Due to the imbalanced nature of the dataset (78 observed MI cases and 1376 non-MI individuals), we employed a generative adversarial network (GAN) model to generate new incident cases, augmenting the dataset and improving feature representation. To predict MI, we further utilized multi-layer perceptron (MLP) models in conjunction with the synthetic minority oversampling technique (SMOTE) and edited nearest neighbor (ENN) methods to address overfitting and underfitting issues, particularly when dealing with imbalanced datasets. To enhance prediction accuracy, we propose a novel GAN for feature-enhanced (GFE) loss function. The GFE loss function resulted in an approximate 2% improvement in prediction accuracy, yielding a final accuracy of 70%. Furthermore, we evaluated the contribution of each clinical variable and metabolite to the predictive model and identified the 10 most significant variables, including glucose tolerance, sex, and physical activity. This is the first study to construct a deep-learning approach for producing 7-year MI predictions using the newly proposed loss function. Our findings demonstrate the promising potential of our technique in identifying novel biomarkers for MI prediction.

Omentin associates with serum metabolite profiles indicating lower diabetes risk: KORA F4 Study

INTRODUCTION

Circulating omentin levels have been positively associated with insulin sensitivity. Although a role for adiponectin in this relationship has been suggested, underlying mechanisms remain elusive. In order to reveal the relationship between omentin and systemic metabolism, this study aimed to investigate associations of serum concentrations of omentin and metabolites.

RESEARCH DESIGN AND METHODS

This study is based on 1124 participants aged 61-82 years from the population-based KORA (Cooperative Health Research in the Region of Augsburg) F4 Study, for whom both serum omentin levels and metabolite concentration profiles were available. Associations were assessed with five multivariable regression models, which were stepwise adjusted for multiple potential confounders, including age, sex, body mass index, waist-to-hip ratio, lifestyle markers (physical activity, smoking behavior and alcohol consumption), serum adiponectin levels, high-density lipoprotein cholesterol, use of lipid-lowering or anti-inflammatory medication, history of myocardial infarction and stroke, homeostasis model assessment 2 of insulin resistance, diabetes status, and use of oral glucose-lowering medication and insulin.

RESULTS

Omentin levels significantly associated with multiple metabolites including amino acids, acylcarnitines, and lipids (eg, sphingomyelins and phosphatidylcholines (PCs)). Positive associations for several PCs, such as diacyl (PC aa C32:1) and alkyl-alkyl (PC ae C32:2), were significant in models 1-4, whereas those with hydroxytetradecenoylcarnitine (C14:1-OH) were significant in all five models. Omentin concentrations were negatively associated with several metabolite ratios, such as the valine-to-PC ae C32:2 and the serine-to-PC ae C32:2 ratios in most models.

CONCLUSIONS

Our results suggest that omentin may influence insulin sensitivity and diabetes risk by changing systemic lipid metabolism, but further mechanistic studies investigating effects of omentin on metabolism of insulin-sensitive tissues are needed.

Association between plant-based or animal-based dietary pattern and plasma glucose during oral glucose tolerance test among Chinese women with gestational diabetes mellitus: a prospective cohort study

OBJECTIVE

This study explored whether plant-based and animal-based dietary patterns are associated with plasma glucose levels during oral glucose tolerance test in women with gestational diabetes mellitus (GDM).

DESIGN

A prospective cohort study was conducted using a Food Frequency Questionnaire to collect dietary data. Dietary patterns were derived using principal component analysis. Multivariate logistic regression analysis was performed to explore the association between dietary patterns and plasma glucose levels. Stratified analyses were conducted according to maternal age, prepregnancy body mass index (BMI) and other confounders.

SETTING AND PARTICIPANTS

The study, conducted in January 2022 in two hospitals in Fujian, China, involved 424 women diagnosed with GDM using a 75 g 2-hour oral glucose tolerance test at 24-28 gestational weeks.

RESULTS

Six maternal dietary patterns (plant based and animal based) were identified. Participants with plant-based pattern had lower 2-hour plasma glucose levels than those with animal-based pattern (β=-0.314; 95% CI (-0.596 to -0.032)). After adjusting the regression model covariates, this significant association remained (β=-0.288; 95% CI (-0.568 to -0.008)) and appeared more pronounced in women aged 30 years or above and those with prepregnancy BMI<24 kg/m2.

CONCLUSIONS

Plant-based pattern is associated with lower plasma glucose levels in women with GDM, which is valuable information for dietary counselling and intervention.

Association of sex hormones and sex hormone-binding globulin with liver fat in men and women: an observational and Mendelian randomization study

Background

Sex hormones and sex hormone-binding globulin (SHBG) may play a role in fatty liver development. We sought to examine the association of various endogenous sex hormones, including testosterone (T), and SHBG with liver fat using complementary observational and Mendelian randomization (MR) analyses.

Methods

The observational analysis included a total of 2,239 participants (mean age 60 years; 35% postmenopausal women) from the population-based KORA study (average follow-up time: 6.5 years). We conducted linear regression analysis to investigate the sex-specific associations of sex hormones and SHBG with liver fat, estimated by fatty liver index (FLI). For MR analyses, we selected genetic variants associated with sex hormones and SHBG and extracted their associations with magnetic resonance imaging measured liver fat from the largest up to date European genome-wide associations studies.

Results

In the observational analysis, T, dihydrotestosterone (DHT), progesterone and 17α-hydroxyprogesterone (17-OHP) were inversely associated with FLI in men, with beta estimates ranging from -4.23 to -2.30 [p-value <0.001 to 0.003]. Whereas in women, a positive association of free T with FLI (β = 4.17, 95%CI: 1.35, 6.98) was observed. SHBG was inversely associated with FLI across sexes [men: -3.45 (-5.13, -1.78); women: -9.23 (-12.19, -6.28)]. No causal association was found between genetically determined sex hormones and liver fat, but higher genetically determined SHBG was associated with lower liver fat in women (β = -0.36, 95% CI: -0.61, -0.12).

Conclusion

Our results provide suggestive evidence for a causal association between SHBG and liver fat in women, implicating the protective role of SHBG against liver fat accumulation.

Effects of Short- And Medium-Term Exposures to Lower Air Temperature on 71 Novel Biomarkers of Subclinical Inflammation: Results from the KORA F4 Study

Increasing evidence has revealed that exposure to low temperatures is linked to a higher risk of chronic diseases and death; however, the mechanisms underlying the observed associations are still poorly understood. We performed a cross-sectional analysis with 1115 participants from the population-based KORA F4 study, which was conducted in Augsburg, Germany, from 2006 to 2008. Seventy-one inflammation-related protein biomarkers were analyzed in serum using proximity extension assay technology. We employed generalized additive models to explore short- and medium-term effects of air temperature on biomarkers of subclinical inflammation at cumulative lags of 0-1 days, 2-6 days, 0-13 days, 0-27 days, and 0-55 days. We found that short- and medium-term exposures to lower air temperature were associated with higher levels in 64 biomarkers of subclinical inflammation, such as Protein S100-A12 (EN-RAGE), Interleukin-6 (IL-6), Interleukin-10 (IL-10), C-C motif chemokine 28 (CCL28), and Neurotrophin-3 (NT-3). More pronounced associations between lower air temperature and higher biomarker of subclinical inflammation were observed among older participants, people with cardiovascular disease or prediabetes/diabetes, and people exposed to higher levels of air pollution (PM2.5, NO2, and O3). Our findings provide intriguing insight into how low air temperature may cause adverse health effects by activating inflammatory pathways.

Associations between medium- and long-term exposure to air temperature and epigenetic age acceleration

Climate change poses a serious threat to human health worldwide, while aging populations increase. However, no study has ever investigated the effects of air temperature on epigenetic age acceleration. This study involved 1,725 and 1,877 participants from the population-based KORA F4 (2006-2008) and follow-up FF4 (2013-2014) studies, respectively, conducted in Augsburg, Germany. The difference between epigenetic age and chronological age was referred to as epigenetic age acceleration and reflected by Horvath's epigenetic age acceleration (HorvathAA), Hannum's epigenetic age acceleration (HannumAA), PhenoAge acceleration (PhenoAA), GrimAge acceleration (GrimAA), and Epigenetic Skin and Blood Age acceleration (SkinBloodAA). Daily air temperature was estimated using hybrid spatiotemporal regression-based models. To explore the medium- and long-term effects of air temperature modeled in time and space on epigenetic age acceleration, we applied generalized estimating equations (GEE) with distributed lag non-linear models, and GEE, respectively. We found that high temperature exposure based on the 8-week moving average air temperature (97.5th percentile of temperature compared to median temperature) was associated with increased HorvathAA, HannumAA, GrimAA, and SkinBloodAA: 1.83 (95% CI: 0.29-3.37), 11.71 (95% CI: 8.91-14.50), 2.26 (95% CI: 1.03-3.50), and 5.02 (95% CI: 3.42-6.63) years, respectively. Additionally, we found consistent results with high temperature exposure based on the 4-week moving average air temperature was associated with increased HannumAA, GrimAA, and SkinBloodAA: 9.18 (95% CI: 6.60-11.76), 1.78 (95% CI: 0.66-2.90), and 4.07 (95% CI: 2.56-5.57) years, respectively. For the spatial variation in annual average temperature, a 1 °C increase was associated with an increase in all five measures of epigenetic age acceleration (HorvathAA: 0.41 [95% CI: 0.24-0.57], HannumAA: 2.24 [95% CI: 1.95-2.53], PhenoAA: 0.32 [95% CI: 0.05-0.60], GrimAA: 0.24 [95%: 0.11-0.37], and SkinBloodAA: 1.17 [95% CI: 1.00-1.35] years). In conclusion, our results provide first evidence that medium- and long-term exposures to high air temperature affect increases in epigenetic age acceleration.

Secondary prevention in diabetic and nondiabetic coronary heart disease patients: Insights from the German subset of the hospital arm of the EUROASPIRE IV and V surveys

BACKGROUND

Patients with coronary heart disease (CHD) with and without diabetes mellitus have an increased risk of recurrent events requiring multifactorial secondary prevention of cardiovascular risk factors. We compared prevalences of cardiovascular risk factors and its determinants including lifestyle, pharmacotherapy and diabetes mellitus among patients with chronic CHD examined within the fourth and fifth EUROASPIRE surveys (EA-IV, 2012-13; and EA-V, 2016-17) in Germany.

METHODS

The EA initiative iteratively conducts European-wide multicenter surveys investigating the quality of secondary prevention in chronic CHD patients aged 18 to 79 years. The data collection in Germany was performed during a comprehensive baseline visit at study centers in Würzburg (EA-IV, EA-V), Halle (EA-V), and Tübingen (EA-V).

RESULTS

384 EA-V participants (median age 69.0 years, 81.3% male) and 536 EA-IV participants (median age 68.7 years, 82.3% male) were examined. Comparing EA-IV and EA-V, no relevant differences in risk factor prevalence and lifestyle changes were observed with the exception of lower LDL cholesterol levels in EA-V. Prevalence of unrecognized diabetes was significantly lower in EA-V as compared to EA-IV (11.8% vs. 19.6%) while the proportion of prediabetes was similarly high in the remaining population (62.1% vs. 61.0%).

CONCLUSION

Between 2012 and 2017, a modest decrease in LDL cholesterol levels was observed, while no differences in blood pressure control and body weight were apparent in chronic CHD patients in Germany. Although the prevalence of unrecognized diabetes decreased in the later study period, the proportion of normoglycemic patients was low. As pharmacotherapy appeared fairly well implemented, stronger efforts towards lifestyle interventions, mental health programs and cardiac rehabilitation might help to improve risk factor profiles in chronic CHD patients.

Environmental risk factors of incident distal sensorimotor polyneuropathy: Results from the prospective population-based KORA F4/FF4 study

Distal sensorimotor polyneuropathy (DSPN) is a common condition in older populations with high prevalence of obesity and type 2 diabetes. We hypothesised that the risk of DSPN is increased by multiple ubiquitous environmental risk factors, particularly in people with obesity. This study was based on 423 individuals aged 62-81 years without DSPN who participated in the population-based Cooperative Health Research in the Region of Augsburg (KORA) F4 survey (2006-2008) in Southern Germany. During 6.5 years of follow-up, 188 participants developed clinical DSPN as assessed by the Michigan Neuropathy Screening Instrument. Environmental exposures, including air temperature, surrounding greenness (assessed with the normalized difference vegetation index [NDVI]), long-term road traffic noise and air pollution, were assessed at participants' residences. The cumulative risk index (CRI) evaluated the joint effects of co-occurring exposures on DSPN risk based on effect estimates from multi-exposure Poisson regression models. The models were adjusted for age, sex, height, waist circumference, smoking, alcohol consumption, physical activity, education and neighbourhood socioeconomic status. In the entire cohort, the co-occurrence of an interquartile range (IQR) decrease in temperature of the warm season and NDVI in a 100-m buffer and of an IQR increase in night-time average traffic noise and in annual average particle number concentration (PNC) was positively associated with incident DSPN (CRI [95 % CI] 1.39 [1.02, 1.91]). Effect estimates for exposure combinations were generally higher in individuals with obesity (CRI 1.34-2.01) than in those without obesity (CRI 0.90-1.33). The four-exposure model showed a twofold increased risk of DSPN among obese (CRI [95 % CI] 2.01 [1.10, 3.67]), but not among non-obese individuals (CRI [95 % CI] 1.18 [0.83, 1.67]). Thus, ubiquitous environmental exposures jointly augment the risk of DSPN in the older population. Lower air temperature in the warm season, less greenness, and higher noise levels and ultrafine particle concentrations identified people with obesity as a particularly vulnerable subgroup.

Fatty liver mediates the association of hyperuricemia with prediabetes and diabetes: a weighting-based mediation analysis

Background

Fatty liver, obesity, and dyslipidemia are associated with prediabetes or diabetes risk, and hyperuricemia co-exists. The present study evaluated the role of multiple mediators, namely, fatty liver, body mass index (BMI), and dyslipidemia, in the association between hyperuricemia and diabetes status.

Methods

Baseline data from the ongoing Fuqing cohort (5,336 participants) were analyzed to investigate the association of hyperuricemia with diabetes status using a multinomial logistic regression model. Furthermore, causal mediation analysis with the weighting-based approach was performed to estimate hyperuricemia's total natural direct effect (tnde), total natural indirect effect (tnie), and total effect (te) on prediabetes and diabetes risk, mediating jointly via fatty liver, BMI, and dyslipidemia.

Results

In multinomial analysis without considering mediators' effects, hyperuricemia was associated with a higher risk of prediabetes only (odds ratio: 1.25; 95% CI: 1.09-1.43; p < 0.001). When fatty liver, BMI, and dyslipidemia were considered as multiple mediators in the association, hyperuricemia was linked to both prediabetes [tnde: 1.11, 95% CI: 1.04-1.11; tnie: 1.07, 95% CI: 1.05-1.09; and overall proportion mediated (pm): 42%, 95% CI: 27%-73%] and diabetes risk (tnde: 0.96, 95% CI: 0.82-1.14; tnie: 1.25, 95% CI: 1.18-1.33; and pm: 100%, 95% CI: 57%-361%). Hyperuricemia showed significant tnde, te, and tnie, mediated by fatty liver jointly with dyslipidemia (pm = 17%) or BMI (pm = 35%), on prediabetes risk.

Conclusion

Hyperuricemia could increase prediabetes or diabetes risk, partially mediated by fatty liver, BMI, and dyslipidemia. Fatty liver is the crucial mediator in the association between hyperuricemia and prediabetes.

Higher Daily Air Temperature Is Associated with Shorter Leukocyte Telomere Length: KORA F3 and KORA F4

Higher air temperature is associated with increased age-related morbidity and mortality. To date, short-term effects of air temperature on leukocyte telomere length have not been investigated in an adult population. We aimed to examine the short-term associations between air temperature and leukocyte telomere length in an adult population-based setting, including two independent cohorts. This population-based study involved 5864 participants from the KORA F3 (2004-2005) and F4 (2006-2008) cohort studies conducted in Augsburg, Germany. Leukocyte telomere length was assessed by a quantitative PCR-based method. We estimated air temperature at each participant's residential address through a highly resolved spatiotemporal model. We conducted cohort-specific generalized additive models to explore the short-term effects of air temperature on leukocyte telomere length at lags 0-1, 2-6, 0-6, and 0-13 days separately and pooled the estimates by fixed-effects meta-analysis. Our study found that between individuals, an interquartile range (IQR) increase in daily air temperature was associated with shorter leukocyte telomere length at lags 0-1, 2-6, 0-6, and 0-13 days (%change: -2.96 [-4.46; -1.43], -2.79 [-4.49; -1.07], -4.18 [-6.08; -2.25], and -6.69 [-9.04; -4.27], respectively). This meta-analysis of two cohort studies showed that between individuals, higher daily air temperature was associated with shorter leukocyte telomere length.

Network reconstruction for trans acting genetic loci using multi-omics data and prior information

BACKGROUND

Molecular measurements of the genome, the transcriptome, and the epigenome, often termed multi-omics data, provide an in-depth view on biological systems and their integration is crucial for gaining insights in complex regulatory processes. These data can be used to explain disease related genetic variants by linking them to intermediate molecular traits (quantitative trait loci, QTL). Molecular networks regulating cellular processes leave footprints in QTL results as so-called trans-QTL hotspots. Reconstructing these networks is a complex endeavor and use of biological prior information can improve network inference. However, previous efforts were limited in the types of priors used or have only been applied to model systems. In this study, we reconstruct the regulatory networks underlying trans-QTL hotspots using human cohort data and data-driven prior information.

METHODS

We devised a new strategy to integrate QTL with human population scale multi-omics data. State-of-the art network inference methods including BDgraph and glasso were applied to these data. Comprehensive prior information to guide network inference was manually curated from large-scale biological databases. The inference approach was extensively benchmarked using simulated data and cross-cohort replication analyses. Best performing methods were subsequently applied to real-world human cohort data.

RESULTS

Our benchmarks showed that prior-based strategies outperform methods without prior information in simulated data and show better replication across datasets. Application of our approach to human cohort data highlighted two novel regulatory networks related to schizophrenia and lean body mass for which we generated novel functional hypotheses.

CONCLUSIONS

We demonstrate that existing biological knowledge can improve the integrative analysis of networks underlying trans associations and generate novel hypotheses about regulatory mechanisms.

Association between the fatty liver index and chronic kidney disease: the population-based KORA study

BACKGROUND

We aimed to evaluate the relationship of fatty liver, estimated by fatty liver index (FLI), with kidney function and chronic kidney disease (CKD) in a German cohort study, given the lack of prospective evidence in Europeans.

METHODS

We included 2920 participants (51.6% women, mean age 56.1 years) from the KORA study, of which 1991 were followed up for an average of 6.4 (± 0.3) years. Kidney function was assessed using the glomerular filtration rate estimated by creatinine (eGFR-cr) or cystatin C (eGFR-cc). We used multiple logistic or linear regressions to evaluate the associations between FLI, kidney function and CKD (eGFR < 60 ml/min per 1.73 m2), and mediation analysis to explore the mediation effects of metabolic factors.

RESULTS

The prevalence of FLI ≥ 60 and CKD were 40.4% and 5.6% at baseline, and 182 participants developed CKD during the follow-up. Cross-sectionally, FLI was significantly inversely associated with eGFR-cc [β, 95%CI: -1.14 (-1.81, -0.47)] and prevalent CKD based on eGFR-cc [OR, 95%CI: 1.28 (1.01, 1.61)], but not with other markers. After adjusting for lifestyle factors, we found a positive association between FLI and incident CKD defined by eGFR-cc or/eGFR-cr, which was attenuated after controlling for metabolic risk factors. Mediation analysis showed that the association was completely mediated by inflammation, diabetes and hypertension jointly.

CONCLUSIONS

The positive association between FLI and CKD incidence was fully mediated by the joint effect of metabolic risk factors. Future longitudinal studies need to explore the chronological interplay between fatty liver, cardiometabolic risk factors and kidney function with repeated measurements.

Association of C-Terminal Pro-Endothelin-1 with Mortality in the Population-Based KORA F4 Study

Introduction

Endothelin-1 and its prohormone C-terminal pro-endothelin-1 (CT-proET-1) have been linked to metabolic alterations, inflammatory responses and cardiovascular events in selected study populations. We analyzed the association of CT-proET-1 with cardiovascular events and mortality, carotid intima-media-thickness as surrogate for early atherosclerotic lesions, biomarkers of subclinical inflammation and adipokines in a population-based study.

Methods

The cross-sectional and prospective analyses used data from the KORA F4 study with a median follow-up time of 9.1 (8.8–9.4) years. Data on CT-proET-1 and mortality were available for 1554 participants, data on the other outcomes in subgroups (n = 596–1554). The associations were estimated using multivariable linear regression and Cox proportional hazard models adjusted for sex, age, body mass index, estimated glomerular filtration rate, arterial hypertension, diabetes, low-density and high-density lipoprotein cholesterol, current and former smoking and physical activity. The Bonferroni method was used to correct for multiple testing.

Results

In the fully adjusted model, CT-proET-1 was associated with cardiovascular (hazard ratio (HR) per standard deviation increase: 1.66; 95% confidence interval (CI): 1.10–2.51; p = 0.017) and all-cause mortality (HR: 2.03; 95% CI 1.55–2.67; p < 0.001), but not with cardiovascular events, and was inversely associated with the intima-media thickness (β: −0.09 ± 0.03; p = 0.001). CT-proET-1 was positively associated with five out of ten biomarkers of subclinical inflammation and with two out of five adipokines after correction for multiple testing. After inclusion of biomarkers of subclinical inflammation in the Cox proportional hazard model, the association of CT-proET-1 with all-cause mortality persisted (p < 0.001).

Conclusion

These results emphasize the complexity of endothelin-1 actions and/or indicator functions of CT-proET-1. CT-proET-1 is a risk marker for all-cause mortality, which is likely independent of vascular endothelin-1 actions, cardiovascular disease and inflammation.

Association of circulating MR-proADM with all-cause and cardiovascular mortality in the general population: Results from the KORA F4 cohort study

Background and aim

Despite its vasodilatory effect, adrenomedullin and its surrogate mid-regional pro-adrenomedullin (MR-proADM) have been found to be positively associated with all-cause and cardiovascular mortality. However, the underlying mechanisms thereof remain unclear and the associations were mostly shown in geriatric cohorts or in patients with chronic diseases. Therefore, we aimed to investigate the possible involvement of abdominal obesity, selected adipokines, and biomarkers of subclinical inflammation in the association of MR-proADM with mortality in a population based study cohort.

Methods

Prospective analysis of the KORA F4 study; median follow-up 9.1 (8.8–9.4) years. Complete data on MR-proADM and mortality was available for 1551 participants, aged 56.9±12.9 years (mean±SD). Correlation and regression analyses of MR-proADM with overall (BMI) and abdominal obesity (waist circumference), selected adipokines and biomarkers of subclinical inflammation. Cox proportional hazard models on the association of MR-proADM with all-cause and cardiovascular mortality with adjustment for cardiovascular risk factors and selected biomarkers in study subgroups (n = 603–1551).

Results

MR-proADM associated with all-cause (HR (95%CI): 2.37 (1.72–3.26) and 2.31 (1.67–3.20)) and cardiovascular mortality (4.28 (2.19–8.39) and 4.44 (2.25–8.76)) after adjustment for traditional cardiovascular risk factors including BMI or waist circumference, respectively. MR-proADM was further associated with four out of seven examined adipokines (leptin, retinol-binding protein-4, chemerin, and adiponectin) and with five out of eleven examined biomarkers of subclinical inflammation (high-sensitivity C-reactive protein, interleukin-6, myeloperoxidase, interleukin-22, and interleukin-1 receptor antagonist) after multivariable adjustment and correction for multiple testing. However, only IL-6 substantially attenuated the association of MR-proADM with all-cause mortality.

Conclusions

We found an association of MR-proADM with (abdominal) obesity, selected adipokines, and biomarkers of subclinical inflammation. However, the association of MR-proADM with mortality was independent of these parameters. Future studies should investigate the role of IL-6 and further characteristics of subclinical inflammation in the association between MR-proADM and all-cause mortality.

Association of renin and aldosterone with glucose metabolism in a Western European population: the KORA F4/FF4 study

INTRODUCTION

Primary aldosteronism is associated with impaired glucose tolerance. Whether plasma aldosterone and/or renin concentrations are associated with type 2 diabetes and continuous measures of glucose metabolism in the general population is still under debate.

RESEARCH DESIGN AND METHODS

The analyses included 2931 participants of the KORA F4 study at baseline and 2010 participants of the KORA FF4 study after a median follow-up of 6.5 years. The associations of active plasma renin and aldosterone concentrations with type 2 diabetes and continuous measures of glucose metabolism were assessed using logistic and linear regression models. Results were adjusted for sex, age, body mass index (BMI), estimated glomerular filtration rate, potassium, use of ACE inhibitors, angiotensin receptor blockers, beta blockers, diuretics and calcium channel blockers.

RESULTS

Cross-sectionally, renin was associated with type 2 diabetes (OR per SD: 1.25, 95% CI 1.10 to 1.43, p<0.001), fasting glucose, 2-hour glucose, insulin, proinsulin, HOMA-B (homeostasis model assessment of beta cell function) and HOMA-IR (homeostasis model assessment of insulin resistance) (all p values <0.001). Aldosterone was not associated with type 2 diabetes (OR: 1.04, 95% CI 0.91 to 1.19; p=0.547) but with insulin, proinsulin and HOMA-IR (all p values <0.001). The aldosterone-renin ratio was inversely associated with type 2 diabetes and several measures of glucose metabolism. Longitudinally, neither renin (OR: 1.12, 95% CI 0.92 to 1.36) nor aldosterone (OR: 0.91, 95% CI 0.74 to 1.11) were associated with incident type 2 diabetes. Renin was inversely associated with changes of insulin concentrations.

CONCLUSIONS

In the KORA F4/FF4 study, renin and aldosterone were not associated with incident type 2 diabetes and largely unrelated to changes of measures of glucose metabolism. Cross-sectionally, aldosterone was associated with surrogate parameters of insulin resistance. However, these associations were not independent of renin.

Novel biomarkers of inflammation, kidney function and chronic kidney disease in the general population

BACKGROUND

Inflammatory processes have been implicated in the development of chronic kidney disease (CKD). We investigated the association of a large panel of inflammatory biomarkers reflecting aspects of immunity with kidney function and CKD incidence.

METHODS

We used data from two independent population-based studies, KORA F4 (discovery, n = 1,110, mean age 70.3 years, 48.7% male) and ESTHER (replication, n = 1,672, mean age 61.9 years, 43.6% male). Serum levels of biomarkers were measured using proximity extension assay technology. The association of biomarkers with estimated glomerular filtration rate (eGFR) at baseline and with incident CKD was investigated using linear and logistic regression models adjusted for cardiorenal risk factors. Independent results from prospective analyses of both studies were pooled. The significance level was corrected for multiple testing by false-discovery rate (PFDR < 0.05.).

RESULTS

In the KORA F4 discovery study, 52 out of 71 inflammatory biomarkers were inversely associated with eGFR estimated based on serum creatinine. Top biomarkers included CD40, TNFRSF9 and IL10RB. Forty-two of these 52 biomarkers were replicated in the ESTHER study. Nine of the 42 biomarkers were associated with incident CKD independently of cardiorenal risk factors in the meta-analysis of the KORA (n = 142, mean follow-up of 6.5 years) and ESTHER (n = 103, mean follow-up of 8 years) studies. Pathway analysis revealed the involvement of inflammatory and immunomodulatory processes reflecting cross-communication of innate and adaptive immune cells.

CONCLUSIONS

Novel and known biomarkers of inflammation were reproducibly associated with kidney function. Future studies should investigate their clinical utility and underlying molecular mechanisms in independent cohorts.

Linking the FTO obesity rs1421085 variant circuitry to cellular, metabolic, and organismal phenotypes in vivo

Variants in FTO have the strongest association with obesity; however, it is still unclear how those noncoding variants mechanistically affect whole-body physiology. We engineered a deletion of the rs1421085 conserved cis-regulatory module (CRM) in mice and confirmed in vivo that the CRM modulates Irx3 and Irx5 gene expression and mitochondrial function in adipocytes. The CRM affects molecular and cellular phenotypes in an adipose depot-dependent manner and affects organismal phenotypes that are relevant for obesity, including decreased high-fat diet-induced weight gain, decreased whole-body fat mass, and decreased skin fat thickness. Last, we connected the CRM to a genetically determined effect on steroid patterns in males that was dependent on nutritional challenge and conserved across mice and humans. Together, our data establish cross-species conservation of the rs1421085 regulatory circuitry at the molecular, cellular, metabolic, and organismal level, revealing previously unknown contextual dependence of the variant's action.

Association of persistent organic pollutants with sensorimotor neuropathy in participants with and without diabetes or prediabetes: Results from the population-based KORA FF4 study

BACKGROUND

Concentrations of persistent organic pollutants (POPs) have been associated with an increased type 2 diabetes (T2D) risk. It remains unclear whether POPs are also associated with the risk of diabetes complications including neuropathy and evidence on this topic is scarce. We aimed to investigate the hypothesis that low-dose background concentrations of POPs were positively associated with distal sensorimotor polyneuropathy (DSPN).

METHODS

This cross-sectional study was based on data from the second follow-up (FF4, 2013-2014, N = 2279) of the population-based KORA S4 study (Augsburg, Germany). The study sample consisted of 200 participants, including four groups of 50 persons each with known T2D, prediabetes, newly diagnosed diabetes, and normal glucose tolerance (NGT) based on an oral glucose tolerance test. We analyzed the association of six most abundant serum concentrations of POPs, including polychlorinated biphenyls (PCBs) as well as organochlorine (OC) pesticides, with DSPN by multivariable logistic regression adjusted for age, sex, glycaemic status, body mass index, physical activity, smoking and alcohol consumption. We assessed effect modification by age, sex, glycaemic status and obesity and conducted two-pollutant models to check the robustness of the estimates.

RESULTS

For all pollutants, the main models indicated no significant association of having DSPN but pointed to rather decreased odds for DSPN. Two-pollutant models supported these findings, though only the association between the combination of PCB-138 and beta-hexachlorocyclohexane (β-HCH) (OR: 0.59; 95% CI: 0.35-0.99) with DSPN became significant. No effect modification was found by age, sex, glycaemic status and obesity.

CONCLUSION

Low-dose concentrations of POPs were not associated with increased odds of having DSPN in T2D, prediabetes and NGT.

Association of Long-Term Air Pollution with Prevalence and Incidence of Distal Sensorimotor Polyneuropathy: KORA F4/FF4 Study

BACKGROUND

Air pollution contributes to type 2 diabetes and cardiovascular diseases, but its relevance for other complications of diabetes, in particular distal sensorimotor polyneuropathy (DSPN), is unclear. Recent studies have indicated that DSPN is also increasingly prevalent in obesity.

OBJECTIVES

We aimed to assess associations of air pollutants with prevalent and incident DSPN in a population-based study of older individuals with high rates of type 2 diabetes and obesity.

METHODS

Cross-sectional analyses on prevalent DSPN were based on 1,075 individuals 62-81 years of age from the German Cooperative Health Research in the Region of Augsburg (KORA) F4 survey (2006-2008). Analyses on incident DSPN included 424 individuals without DSPN at baseline (KORA F4), of whom 188 had developed DSPN by the KORA FF4 survey (2013-2014). Associations of annual average air pollutant concentrations at participants' residences with prevalent and incident DSPN were estimated using Poisson regression models with a robust error variance adjusting for multiple confounders.

RESULTS

Higher particle number concentrations (PNCs) were associated with higher prevalence [risk ratio (RR) per interquartile range (IQR) increase=1.10 (95% CI: 1.01, 1.20)] and incidence [1.11 (95% CI: 0.99, 1.24)] of DSPN. In subgroup analyses, particulate (PNC, PM10, PMcoarse, PM2.5, and PM2.5abs) and gaseous (NOx, NO2) pollutants were positively associated with prevalent DSPN in obese participants, whereas corresponding estimates for nonobese participants were close to the null [e.g., for an IQR increase in PNC, RR=1.17 (95% CI: 1.05, 1.31) vs. 1.06 (95% CI: 0.95, 1.19); pinteraction=0.22]. With the exception of PM2.5abs, corresponding associations with incident DSPN were positive in obese participants but null or inverse for nonobese participants, with pinteraction≤0.13 [e.g., for PNC, RR=1.28 (95% CI: 1.08, 1.51) vs. 1.03 (95% CI: 0.90, 1.18); pinteraction=0.03].

DISCUSSION

Both particulate and gaseous air pollutants were positively associated with prevalent and incident DSPN in obese individuals. Obesity and air pollution may have synergistic effects on the development of DSPN. https://doi.org/10.1289/EHP7311.

Positive association of serum uric acid with new-onset diabetes in Chinese women with hypertension in a retrospective analysis of the China Stroke Primary Prevention Trial

AIMS

To investigate the association of baseline serum uric acid (UA) with new-onset diabetes, and to explore the possible effect modifiers in Chinese adults with hypertension.

MATERIALS AND METHODS

A total of 14 943 hypertensive patients with available UA measurements and without diabetes at baseline were included from the China Stroke Primary Prevention Trial (CSPPT). Participants were randomly assigned to a double-blind daily treatment with 10 mg enalapril and 0.8 mg folic acid or 10 mg enalapril alone. The primary outcome was new-onset diabetes, defined as physician-diagnosed diabetes or use of glucose-lowering drugs during follow-up, or fasting glucose ≥7.0 mmol/L at the exit visit.

RESULTS

Over a median follow-up of 4.5 years, 1623 participants (10.9%) developed diabetes. Overall, there was a positive association between baseline UA and new-onset diabetes in women (per SD increment; adjusted odds ratio [OR] 1.14, 95% confidence interval [CI] 1.07, 1.23), but not in men (adjusted OR 1.01, 95% CI 0.92, 1.10). Moreover, a stronger positive association between baseline UA and new-onset diabetes was found among women with lower time-averaged on-treatment systolic blood pressure during the treatment period (<140 vs. ≥140 mmHg; P-interaction = 0.024), higher baseline body mass index (<24 vs. ≥24 kg/m² ; P-interaction = 0.012), or higher baseline waist circumference (<80 vs. ≥80 cm; P-interaction = 0.032).

CONCLUSIONS

Our study suggested that higher baseline UA was significantly associated with increased risk of new-onset diabetes in hypertensive Chinese women, but not in men. Further prospective studies are required to validate the differential association by sex.

Serum uromodulin is inversely associated with arterial hypertension and the vasoconstrictive prohormone CT-proET-1 in the population-based KORA F4 study

Objectives

Uromodulin has been associated with arterial hypertension in genome-wide association studies, but data from clinical and preclinical studies are inconsistent. We here analyzed the association of serum uromodulin (sUmod) with arterial hypertension and vasoactive hormones in a population-based study.

Methods

In 1108 participants of the KORA F4 study aged 62–81 years, sUmod was measured and the association of sUmod with arterial hypertension was assessed using logistic regression models. The associations of sUmod with renin and aldosterone and with the vasoconstrictive prohormone C-terminal pro-endothelin-1 (CT-proET-1) were analyzed in 1079 participants and in 618 participants, respectively, using linear regression models.

Results

After multivariable adjustment including sex, age, eGFR, BMI, fasting glucose, current smoking, previous stroke and myocardial infarction, sUmod was inversely associated with arterial hypertension (OR 0.78; 95% CI 0.68–0.91; p = 0.001). SUmod was not significantly associated with renin and aldosterone after adjustment for sex, age and eGFR. However, sUmod was inversely associated with CT-proET-1 (β -0.19 ± 0.04; p < 0.001) after adjustment for sex, age, eGFR, BMI, arterial hypertension, fasting glucose, current smoking, previous stroke and myocardial infarction. The association with CT-proET-1 was stronger in participants with hypertension (β -0.22 ± 0.04) than in normotensive participants (β -0.13 ± 0.06; p for interaction hypertension = 0.003 in the model adjusted for hypertension).

Conclusions

SUmod was inversely associated with arterial hypertension and the vasoconstrictive prohormone CT-proET-1, suggesting direct or indirect effects of sUmod on blood pressure regulation.

Proinsulin to insulin ratio is associated with incident type 2 diabetes but not with vascular complications in the KORA F4/FF4 study

INTRODUCTION

We investigated the association of the proinsulin to insulin ratio (PIR) with prevalent and incident type 2 diabetes (T2D), components of the metabolic syndrome, and renal and cardiovascular outcomes in the population-based Cooperative Health Research in the Region of Augsburg (KORA) F4 study (2006-2008)/FF4 study (2013-2014).

RESEARCH DESIGN AND METHODS

The analyses included 1514 participants of the KORA F4 study at baseline and 1132 participants of the KORA FF4 study after a median follow-up time of 6.6 years. All-cause and cardiovascular mortality as well as cardiovascular events were analyzed after a median time of 9.1 and 8.6 years, respectively. The association of PIR with T2D, renal and cardiovascular characteristics and mortality were assessed using logistic regression models. Linear regression analyses were used to assess the association of PIR with components of the metabolic syndrome.

RESULTS

After adjustment for sex, age, body mass index (BMI), and physical activity, PIR was associated with prevalent (OR: 2.24; 95% CI 1.81 to 2.77; p<0.001) and incident T2D (OR: 1.66; 95% CI 1.26 to 2.17; p<0.001). PIR was associated with fasting glucose (β per SD: 0.11±0.02; p<0.001) and HbA1c (β: 0.21±0.02; p<0.001). However, PIR was not positively associated with other components of the metabolic syndrome and was even inversely associated with waist circumference (β: -0.22±0.03; p<0.001), BMI (β: -0.11±0.03; p<0.001) and homeostatic model assessment of insulin resistance (β: -0.22±0.02; p<0.001). PIR was not significantly associated with the intima-media thickness (IMT), decline of kidney function, incident albuminuria, myocardial infarction, stroke, cardiovascular or all-cause mortality.

CONCLUSIONS

In the KORA F4/FF4 cohort, PIR was positively associated with prevalent and incident T2D, but inversely associated with waist circumference, BMI and insulin resistance, suggesting that PIR might serve as a biomarker for T2D risk independently of the metabolic syndrome, but not for microvascular or macrovascular complications.

Serum uromodulin and decline of kidney function in older participants of the population-based KORA F4/FF4 study

Background

Uromodulin, a tissue-specific tubular glycoprotein, has recently emerged as a promising biomarker for kidney function and tubular integrity. However, the association of serum uromodulin (sUmod) with renal function decline is still unknown in an older general population.

Methods

We analysed the association of sUmod with the estimated glomerular filtration rate (eGFR) and albuminuria in 1075 participants of the population-based Cooperative Health Research in the Region of Augsburg (KORA) F4 study, ages 62-81 years, at baseline and prospectively after a mean follow-up time of 6.5 years (n = 605) using logistic and linear regression models as well as receiver operating characteristics (ROC) analyses.

Results

Cross-sectionally, sUmod was positively associated with eGFR (β = 0.31 ± 0.02 per higher standard deviation sUmod; P < 0.001) and inversely associated with the urinary albumin:creatinine ratio (β = -0.19 ± 0.04; P < 0.001) after adjustment for sex, age, body mass index, arterial hypertension, prediabetes and diabetes. After multivariable adjustment including baseline eGFR, sUmod was not associated with incident chronic kidney disease (CKD), defined as a decrease in eGFR <60 mL/min/1.73 m² after 6.5 years of follow-up {odds ratio [OR] 1.02 [95% confidence interval (CI) 0.77-1.36] per higher SD sUmod} but was inversely associated with advanced CKD, defined as incident eGFR <45 mL/min/1.73 m² [OR 0.64 (95% CI 0.42-0.98)]. The ROC showed no added predictive value of sUmod for kidney function decline in the fully adjusted model.

Conclusions

Higher sUmod was inversely associated with progression to advanced kidney disease but does not provide additional predictive value for the development of CKD in elderly participants of the population-based KORA study.

Marked differences in prediabetes- and diabetes-associated comorbidities between men and women-Epidemiological results from a general population-based cohort aged 6-80 years-The LEAD (Lung, hEart, sociAl, boDy) study

BACKGROUND

Based on biological and behavioural diversity sex and gender may affect comorbidities associated with prediabetes and diabetes. Besides evaluating the prevalence of prediabetes and diabetes (using fasting plasma glucose and HbA1_c levels), the primary aim of the study is to investigate sex and gender differences in the prevalence of comorbidities in subjects with prediabetes and diabetes and to identify possible risk factors associated with prediabetes and diabetes.

DESIGN

This observational, population-based cohort study included 11.014 subjects aged 6-80 years. Examinations included blood samples, ankle-brachial index, ECG, dual-energy X-ray absorptiometry scan and an interviewer-administered questionnaire.

RESULTS

Across all ages, prevalence of prediabetes was 20.2% (male 23.6%; female 17.1%), and 5.4% for diabetes (male 7.3%; female 3.7%). The prevalence of prediabetes ranged from 4.4% (6-<10 years) up to 40.4% (70+ years) in men and from 4.8% up to 42.3% in women. Comorbidity profile was markedly different between male and female, particularly in those with prediabetes: women more often suffered from arrhythmia, noncoronary artery disease, osteoporosis, increased systemic inflammatory biomarkers and depression, while men with prediabetes more often showed angina pectoris, myocardial infarction and media sclerosis.

CONCLUSIONS

The unexpected 4.6% prevalence of prediabetes in children aged 6-10 underscores the need for population-based studies across all ages and the onset of prevention of diabetes at a young age. Marked differences have been found in comorbidities as men with prediabetes and diabetes more often suffer from cardiovascular disease, while women more often show arrhythmia, noncoronary artery disease, increased systemic inflammatory biomarkers and depression.

Serum uromodulin and risk for cardiovascular morbidity and mortality in the community-based KORA F4 study

BACKGROUND AND AIMS

Serum uromodulin, a novel biomarker of kidney function and tubular integrity, has been linked to cardiovascular events and total mortality in patients at high cardiovascular risk. Here, we analyze the association of serum uromodulin with cardiovascular morbidity and cardiovascular as well as total mortality in the population-based KORA F4 study stratified by sex.

METHODS

Baseline serum uromodulin was measured in 1079 participants of the KORA F4 study (age 62-81 years). Using multivariable adjusted Cox proportional hazards models, the associations of serum uromodulin with total mortality and cardiovascular mortality were analyzed after a median follow-up period of 8.6 years, and with non-fatal and fatal stroke and myocardial infarction/coronary death after a median follow-up time of 8.4 years.

RESULTS

Serum uromodulin was significantly inversely associated with total mortality (HR 0.65; 95% CI 0.53-0.79 per standard deviation of logarithmized serum uromodulin; p < 0.001) and cardiovascular mortality (HR 0.70; 95% CI 0.52-0.93) in men, but not in women (HR for all-cause mortality in women 0.98; 95% CI 0.77-1.25, HR for cardiovascular mortality 0.78; 95% CI 0.56-1.11) after adjustment for age, BMI, diabetes and eGFR. In addition, serum uromodulin was significantly inversely associated with incident stroke in men (HR 0.68; 95% CI 0.50-0.92), but not in women (HR 0.96; 95% CI 0.68-1.38) after multivariable adjustment. The association of serum uromodulin with incident myocardial infarction was attenuated and lost significance after multivariable adjustment in both sexes.

CONCLUSIONS

Serum uromodulin is an independent biomarker for total and cardiovascular mortality in men from the general community aged 62 years or older.

Risk for cardiovascular events responds nonlinearly to carotid intima-media thickness in the KORA F4 study

BACKGROUND AND AIMS

Risk assessment studies on the impact of carotid intima-media thickness (CIMT) on cardiovascular events (CVEs) often apply a linear relationship in Cox models of proportional hazards. However, CVEs are mostly induced through rupture of plaques driven by nonlinear mechanical properties of the arterial wall. Hence, the risk response might be nonlinear as well and should be detectable in CVE incidence data when associated with CIMT as surrogate variable for atherosclerotic wall degeneration.

METHODS

To test this hypothesis, we investigate the KORA F4 study comprising 2580 participants with CIMT measurements and 153 first CVEs (86 strokes and 67 myocardial infarctions). CIMT is only a moderate predictor of CVE risk due to confounding by attained age. Biological evidence suggests that age-related CIMT growth is not entirely connected with atherosclerosis. To explore the complex relations between age, CIMT and CVE risk, we apply linear and nonlinear models of both CIMT and dnCIMT, defined as deviation from a sex and age-adjusted normal value.

RESULTS

Based on goodness-of-fit and biological plausibility, threshold and logistic step models clearly reveal nonlinear risk response relations for vascular covariables CIMT and dnCIMT. The effect is more pronounced for models involving dnCIMT as novel risk factor, which is not correlated with age.

CONCLUSIONS

Compared to the standard approach of risk assessment with linear models involving CIMT, the application of excess dnCIMT with nonlinear risk responses leads to a more precise identification of asymptomatic high risk patients, especially at younger age.

Sex-Specific Association of Serum Uric Acid Level and Change in Hyperuricemia Status with Risk of Type 2 Diabetes Mellitus: A Large Cohort Study in China

BACKGROUND

Conflicting findings have been reported regarding the sex-specific association between serum uric acid (SUA) level and type 2 diabetes mellitus (T2DM) risk, and no study has explored the association between the change in hyperuricemia status and T2DM risk. The study was aimed at exploring the sex-specific association of baseline SUA and changes in hyperuricemia status with T2DM risk.

METHODS

We included 37,296 eligible adults without T2DM at the first examination who attended the baseline examination and at least one follow-up annual examination. Cox and logistic regression models were used to calculate hazard ratios (HRs) and odds ratios (ORs) with their 95% confidence intervals (CIs) for T2DM risk associated with baseline SUA and the change in hyperuricemia status, respectively.

RESULTS

During a median follow-up of 3.09 years, of 37,296 eligible adults, 2,263 developed T2DM. Compared with the first SUA quartile, higher quartiles were associated with an increased risk of T2DM in women (HR 1.78, 95% CI 1.17-2.71 for Q3 and 1.93, 1.27-2.93 for Q4; P _trend < 0.001) but not in men. Compared with women with a persistent normal SUA level at baseline and the last follow-up, T2DM risk increased significantly among those whose SUA status changed from normal at baseline to hyperuricemia at the last follow-up (OR 1.71, 95% CI 1.12-2.55) and those with persistent hyperuricemia at baseline and the last follow-up (OR 2.37, 95% CI 1.60-3.46). However, for men, a nonsignificant association was found between the change in hyperuricemia status and T2DM risk.

CONCLUSIONS

Baseline SUA and the change in hyperuricemia status were associated with T2DM risk only among women. The findings suggest the importance of monitoring SUA levels and maintaining them within a normal range for preventing or reducing incident T2DM in Chinese women.

Size and Shape of Associations of OGTT as Well as Mediating Effects on Adverse Pregnancy Outcomes Among Women With Gestational Diabetes Mellitus: Population-Based Study From Southern Han Chinese

Objective: To explore the size and shape association of OGTT values with adverse pregnancy complications among women with gestational diabetes mellitus (GDM) in Southern Han Chinese population and further analyze their mediating effects with maternal age in outcomes. Methods: 6,861 women with GDM were included in the study. Logistic regression was used to identify the correlations between OGTT values and adverse pregnancy outcomes of GDM. Restricted cubic spline nested logistic regression was conducted to investigate potential non-linear and linear associations. Mediating effect among maternal age, OGTT and adverse outcomes were explored. Results: Women with GDM had a mean age of 31.83, and 24.49% had advanced maternal age (≥35 years). In logistic regression with adjustment, compared with lower OGTT0 (<5.1 mmol/L), GDM patients with higher OGTT0 (≥5.1 mmol/L) exhibited 1.891 (95% CI: 1.441-2.298, P < 0.001), 1.284 (1.078-1.529, P = 0.005), 1.285 (1.065-1.550, P = 0.009), and 1.302 (1.067-1.590, P = 0.010) times increased risk of hypertensive disorders of pregnancy (HDP), preterm, neonatal hyperbilirubinemia, and macrosomia, respectively. GDM patients with higher OGTT1 (≥10 mmol/L) had only found to exhibited 1.473-fold (1.162-1.867, P = 0.001) increasing risk of HDP than those with lower OGTT1 (<10 mmol/L). No adverse outcome was identified to associate with higher OGTT2 (≥8.5 mmol/L). Linear relationships (non-linear P > 0.05) were observed between OGTT0 and HDP, preterm, neonatal hyperbilirubinemia, and macrosomia in both maternal age groups (<35 and ≥35 years). Non-linear associations of OGTT1 with incidence of HDP, preterm, and neonatal hyperbilirubinemia were detected in GDM patients younger than 35 years (non-linear P = 0.037, P = 0.049, P = 0.039, respectively), rising more steeply at higher values. Similar non-linearity was noted for OGTT2 with HDP in older patients. All OGTT values had significant mediating effects on some special complications caused by higher age. Conclusion: Higher fasting plasma glucose was more strongly linked to adverse pregnancy outcomes among GDM patients. Both linearity and Non-linearity of associations between glucose and complications should be taken into account. A careful reconsideration of GDM with hierarchical and individualized management according to OGTT is needed.

Serum Adiponectin Levels Are Positively Associated With Diabetic Peripheral Neuropathy in Chinese Patients With Type 2 Diabetes

OBJECTIVE

To investigate the association between serum adiponectin levels and diabetic peripheral neuropathy (DPN) in Chinese type 2 diabetes (T2D) patients.

DESIGN AND METHODS

Two hundred nineteen T2D patients aged 40-79 years were divided into two groups according to whether they had DPN. The systemic levels of five biomarkers were measured using a human adipokine multiplexed bead-based immunoassay. Diabetic peripheral neuropathy diagnostic criteria included both common DPN symptoms and neurological screening tests.

RESULTS

Most features of DPN (n=98) and non-DPN patients (n=121) are similar, but the DPN patients were slightly older, had longer diabetes duration, higher hemoglobin (Hb) A1c, lower estimated glomerular filtration rates (eGFR), less exercise, and used lipid-lowering drugs more often. Serum adiponectin levels of DPN patients were higher than that of non-DPN patients (8.13 vs. 9.63 mg/ml, P = 0.004). Serum adiponectin levels were positively associated with DPN after adjusting for age, gender, body mass index, hypertension, HbA1c, alcohol intake, smoking status, physical activity, log-transformed low density lipoprotein cholesterol, lipid-lowering drug usage, eGFR, and diabetes duration {odds ratio (OR) 1.72 [95% confidence interval (CI) 1.02-2.89], P = 0.041}. The OR refers to a doubling in biomarkers.

CONCLUSIONS

Serum adiponectin levels were higher in DPN patients compared to non‑DPN patients in this Chinese T2D population. Serum adiponectin levels were positively associated with DPN presence, independent of multiple confounders.

Serum uromodulin is inversely associated with the metabolic syndrome in the KORA F4 study

OBJECTIVE

Metabolic syndrome and obesity are risk factors for chronic kidney disease. However, early kidney alterations may escape diagnosis in these conditions due to glomerular hyperfiltration. Uromodulin, a glycoprotein exclusively synthesized in tubular cells of the thick ascending limb of Henle's loop, is a novel tissue-specific biomarker for kidney function. In contrast to the commonly used markers creatinine and cystatin C, serum uromodulin does not primarily depend on glomerular filtration. We hypothesized that serum uromodulin is a marker for metabolic syndrome and related components.

DESIGN

The analyses included 1088 participants of the population-based KORA F4 study aged 62-81 years. Metabolic syndrome was present in 554 participants. After a mean follow-up time of 6.5 years, 621 participants were reevaluated, of which 92 had developed incident metabolic syndrome.

METHODS

The association of serum uromodulin with metabolic syndrome and its components were assessed using multivariable logistic regression models.

RESULTS

Serum uromodulin was inversely associated with metabolic syndrome after adjustment for sex, age, estimated glomerular filtration rate, physical activity, smoking, alcohol consumption and high-sensitivity C-reactive protein (OR 0.65; 95% CI 0.56-0.76 per standard deviation uromodulin; P < 0.001). Serum uromodulin was inversely associated with all single components of metabolic syndrome. However, serum uromodulin was not associated with new-onset metabolic syndrome after the follow-up period of 6.5 ± 0.3 years (OR 1.18; 95% CI 0.86-1.60).

CONCLUSIONS

Serum uromodulin is independently associated with prevalent, but not with incident metabolic syndrome. Low serum uromodulin may indicate a decreased renal reserve in the metabolic syndrome.

Discovery of biomarkers for glycaemic deterioration before and after the onset of type 2 diabetes: descriptive characteristics of the epidemiological studies within the IMI DIRECT Consortium

AIMS/HYPOTHESIS

Here, we describe the characteristics of the Innovative Medicines Initiative (IMI) Diabetes Research on Patient Stratification (DIRECT) epidemiological cohorts at baseline and follow-up examinations (18, 36 and 48 months of follow-up).

METHODS

From a sampling frame of 24,682 adults of European ancestry enrolled in population-based cohorts across Europe, participants at varying risk of glycaemic deterioration were identified using a risk prediction algorithm (based on age, BMI, waist circumference, use of antihypertensive medication, smoking status and parental history of type 2 diabetes) and enrolled into a prospective cohort study (n = 2127) (cohort 1, prediabetes risk). We also recruited people from clinical registries with type 2 diabetes diagnosed 6-24 months previously (n = 789) into a second cohort study (cohort 2, diabetes). Follow-up examinations took place at ~18 months (both cohorts) and at ~48 months (cohort 1) or ~36 months (cohort 2) after baseline examinations. The cohorts were studied in parallel using matched protocols across seven clinical centres in northern Europe.

RESULTS

Using ADA 2011 glycaemic categories, 33% (n = 693) of cohort 1 (prediabetes risk) had normal glucose regulation and 67% (n = 1419) had impaired glucose regulation. Seventy-six per cent of participants in cohort 1 was male. Cohort 1 participants had the following characteristics (mean ± SD) at baseline: age 62 (6.2) years; BMI 27.9 (4.0) kg/m²; fasting glucose 5.7 (0.6) mmol/l; 2 h glucose 5.9 (1.6) mmol/l. At the final follow-up examination the participants' clinical characteristics were as follows: fasting glucose 6.0 (0.6) mmol/l; 2 h OGTT glucose 6.5 (2.0) mmol/l. In cohort 2 (diabetes), 66% (n = 517) were treated by lifestyle modification and 34% (n = 272) were treated with metformin plus lifestyle modification at enrolment. Fifty-eight per cent of participants in cohort 2 was male. Cohort 2 participants had the following characteristics at baseline: age 62 (8.1) years; BMI 30.5 (5.0) kg/m²; fasting glucose 7.2 (1.4) mmol/l; 2 h glucose 8.6 (2.8) mmol/l. At the final follow-up examination, the participants' clinical characteristics were as follows: fasting glucose 7.9 (2.0) mmol/l; 2 h mixed-meal tolerance test glucose 9.9 (3.4) mmol/l.

CONCLUSIONS/INTERPRETATION

The IMI DIRECT cohorts are intensely characterised, with a wide-variety of metabolically relevant measures assessed prospectively. We anticipate that the cohorts, made available through managed access, will provide a powerful resource for biomarker discovery, multivariate aetiological analyses and reclassification of patients for the prevention and treatment of type 2 diabetes.

Impaired Glucose Metabolism in Primary Aldosteronism Is Associated With Cortisol Cosecretion

CONTEXT

Primary aldosteronism (PA) is associated with higher cardiovascular morbidity and metabolic risks. Recent studies report glucocorticoid cosecretion as a relevant phenotype of PA, which could contribute to associated risks, including type 2 diabetes mellitus (T2DM). The relationship between autonomous cortisol secretion (ACS) and glucose metabolism in PA has not been investigated.

OBJECTIVE

To evaluate the prevalence of impaired glucose homeostasis in patients with PA according to cortisol cosecretion.

DESIGN

We performed oral glucose tolerance tests (OGTTs) and complete testing for hypercortisolism [1-mg dexamethasone suppression test (DST), late-night salivary cortisol, 24-hour urinary free cortisol] in 161 newly diagnosed patients with PA of the German Conn Registry. Seventy-six of 161 patients were reevaluated at follow-up. We compared our results to a population-based sample from the Cooperative Health Research in the Region of Augsburg (KORA)-F4 study matched to the participants with PA (3:1) by sex, age, and body mass index.

RESULTS

At the time of diagnosis, 125 patients (77.6%) had a pathological response in at least one of the Cushing screening tests; T2DM was diagnosed in 6.4% of these 125 cases. Patients with a pathological DST exhibited significantly higher 2-hour plasma glucose in OGTTs and were significantly more often diagnosed with T2DM than were patients with a normal DST (20% vs 0.8%, P < 0.0001) and matched controls from the KORA study (20.6% vs 5.9%, P = 0.022). Patients with PA without ACS tended to have higher homeostatic model assessment of insulin resistance levels than did KORA control subjects (P = 0.05).

CONCLUSION

ACS appears frequently in patients with PA and is associated with impaired glucose metabolism, which could increase the risk of T2DM. PA itself seems to enhance insulin resistance.

Comparison of metabolite networks from four German population-based studies

Background

Metabolite networks are suggested to reflect biological pathways in health and disease. However, it is unknown whether such metabolite networks are reproducible across different populations. Therefore, the current study aimed to investigate similarity of metabolite networks in four German population-based studies.

Methods

One hundred serum metabolites were quantified in European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam (n = 2458), EPIC-Heidelberg (n = 812), KORA (Cooperative Health Research in the Augsburg Region) (n = 3029) and CARLA (Cardiovascular Disease, Living and Ageing in Halle) (n = 1427) with targeted metabolomics. In a cross-sectional analysis, Gaussian graphical models were used to construct similar networks of 100 edges each, based on partial correlations of these metabolites. The four metabolite networks of the top 100 edges were compared based on (i) common features, i.e. number of common edges, Pearson correlation (r) and hamming distance (h); and (ii) meta-analysis of the four networks.

Results

Among the four networks, 57 common edges and 66 common nodes (metabolites) were identified. Pairwise network comparisons showed moderate to high similarity (r = 63–0.96, h = 7–72), among the networks. Meta-analysis of the networks showed that, among the 100 edges and 89 nodes of the meta-analytic network, 57 edges and 66 metabolites were present in all the four networks, 58–76 edges and 75–89 nodes were present in at least three networks, and 63–84 edges and 76–87 edges were present in at least two networks. The meta-analytic network showed clear grouping of 10 sphingolipids, 8 lyso-phosphatidylcholines, 31 acyl-alkyl-phosphatidylcholines, 30 diacyl-phosphatidylcholines, 8 amino acids and 2 acylcarnitines.

Conclusions

We found structural similarity in metabolite networks from four large studies. Using a meta-analytic network, as a new approach for combining metabolite data from different studies, closely related metabolites could be identified, for some of which the biological relationships in metabolic pathways have been previously described. They are candidates for further investigation to explore their potential role in biological processes.

Serum uromodulin is associated with but does not predict type 2 diabetes in elderly KORA F4/FF4 study participants

AIMS

Serum uromodulin has recently emerged as promising biomarker for kidney function and was suggested to be associated with type 2 diabetes (T2D) in coronary patients. Here, we analyzed the association of serum uromodulin with T2D in the population-based KORA F4/FF4 study.

METHODS

In 1119 participants of the KORA F4 study aged 62 - 81 years, serum uromodulin was measured and the association of serum uromodulin with T2D was assessed using logistic and linear regression models stratified for sex. After a mean follow-up time of 6.5 years, 635 participants where reevaluated. Glucose tolerance status was determined by oral glucose tolerance test at baseline and at the follow-up examination except in cases of known T2D.

RESULTS

Serum uromodulin was inversely associated with T2D in the crude analysis and after adjustment for age and BMI in men (p < 0.001) and in women (p < 0.05). After further adjustment for estimated glomerular filtration rate, serum uromodulin was significantly inversely associated with T2D in men (p < 0.001), but not in women. Serum uromodulin was not associated with prediabetes after multivariate adjustment and did not predict T2D in men or in women after the follow-up time of 6.5 ± 0.3 years.

CONCLUSIONS

In participants of the KORA F4 study, serum uromodulin is independently associated with T2D in men, but is no predictor of future development of T2D.

General and Abdominal Obesity and Incident Distal Sensorimotor Polyneuropathy: Insights Into Inflammatory Biomarkers as Potential Mediators in the KORA F4/FF4 Cohort

OBJECTIVE

To investigate the associations between different anthropometric measurements and development of distal sensorimotor polyneuropathy (DSPN) considering interaction effects with prediabetes/diabetes and to evaluate subclinical inflammation as a potential mediator.

RESEARCH DESIGN AND METHODS

This study was conducted among 513 participants from the Cooperative Health Research in the Region of Augsburg (KORA) F4/FF4 cohort (aged 62-81 years). Anthropometry was measured at baseline. Incident DSPN was defined by neuropathic impairments using the Michigan Neuropathy Screening Instrument at baseline and follow-up. Associations between anthropometric measurements and DSPN were estimated by multivariable logistic regression. Potential differences by diabetes status were assessed using interaction terms. Mediation analysis was conducted to determine the mediation effect of subclinical inflammation in these associations.

RESULTS

After a mean follow-up of 6.5 years, 127 cases with incident DSPN were detected. Both general and abdominal obesity were associated with development of DSPN. The odds ratios (95% CI) of DSPN were 3.06 (1.57; 5.97) for overweight, 3.47 (1.72; 7.00) for obesity (reference: normal BMI), and 1.22 (1.07; 1.38) for 5-cm differences in waist circumference, respectively. Interaction analyses did not indicate any differences by diabetes status. Two chemokines (C-C motif chemokine ligand 7 [CCL7] and C-X-C motif chemokine ligand 10 [CXCL10]) and one neuron-specific marker (Delta/Notch-like epidermal growth factor-related receptor [DNER]) were identified as potential mediators, which explained a proportion of the total effect up to 11% per biomarker.

CONCLUSIONS

General and abdominal obesity were associated with incident DSPN among individuals with and without diabetes, and this association was partly mediated by inflammatory markers. However, further mechanisms and biomarkers should be investigated as additional mediators to explain the remainder of this association.

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 (HbA_1c , 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 HbA_1c and HOMA-ß while changes in adiponectin were inversely associated with changes in HbA_1c . 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.

A Systemic Inflammatory Signature Reflecting Cross Talk Between Innate and Adaptive Immunity Is Associated With Incident Polyneuropathy: KORA F4/FF4 Study

Prospective analyses of biomarkers of inflammation and distal sensorimotor polyneuropathy (DSPN) are scarce and limited to innate immunity. We therefore aimed to assess associations between biomarkers reflecting multiple aspects of immune activation and DSPN. The study was based on 127 case subjects with incident DSPN and 386 noncase subjects from the population-based Cooperative Health Research in the Region of Augsburg (KORA) F4/FF4 cohort (follow-up 6.5 years). Proximity extension assay technology was used to measure serum levels of biomarkers of inflammation. Of 71 biomarkers assessed, 26 were associated with incident DSPN. After adjustment for multiple testing, higher levels of six biomarkers remained related to incident DSPN. Three of these proteins (MCP-3/CCL7, MIG/CXCL9, IP-10/CXCL10) were chemokines, and the other three (DNER, CD40, TNFRSF9) were soluble forms of transmembrane receptors. The chemokines had neurotoxic effects on neuroblastoma cells in vitro. Addition of all six biomarkers improved the C statistic of a clinical risk model from 0.748 to 0.783 (P = 0.011). Pathway analyses indicated that multiple cell types from innate and adaptive immunity are involved in the development of DSPN. We thus identified novel associations between biomarkers of inflammation and incident DSPN pointing to a complex cross talk between innate and adaptive immunity in the pathogenesis of the disease.

Development of type 2 diabetes mellitus in people with intermediate hyperglycaemia

BACKGROUND

Intermediate hyperglycaemia (IH) is characterised by one or more measurements of elevated blood glucose concentrations, such as impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and elevated glycosylated haemoglobin A1c (HbA1c). These levels are higher than normal but below the diagnostic threshold for type 2 diabetes mellitus (T2DM). The reduced threshold of 5.6 mmol/L (100 mg/dL) fasting plasma glucose (FPG) for defining IFG, introduced by the American Diabetes Association (ADA) in 2003, substantially increased the prevalence of IFG. Likewise, the lowering of the HbA1c threshold from 6.0% to 5.7% by the ADA in 2010 could potentially have significant medical, public health and socioeconomic impacts.

OBJECTIVES

To assess the overall prognosis of people with IH for developing T2DM, regression from IH to normoglycaemia and the difference in T2DM incidence in people with IH versus people with normoglycaemia.

SEARCH METHODS

We searched MEDLINE, Embase, ClincialTrials.gov and the International Clinical Trials Registry Platform (ICTRP) Search Portal up to December 2016 and updated the MEDLINE search in February 2018. We used several complementary search methods in addition to a Boolean search based on analytical text mining.

SELECTION CRITERIA

We included prospective cohort studies investigating the development of T2DM in people with IH. We used standard definitions of IH as described by the ADA or World Health Organization (WHO). We excluded intervention trials and studies on cohorts with additional comorbidities at baseline, studies with missing data on the transition from IH to T2DM, and studies where T2DM incidence was evaluated by documents or self-report only.

DATA COLLECTION AND ANALYSIS

One review author extracted study characteristics, and a second author checked the extracted data. We used a tailored version of the Quality In Prognosis Studies (QUIPS) tool for assessing risk of bias. We pooled incidence and incidence rate ratios (IRR) using a random-effects model to account for between-study heterogeneity. To meta-analyse incidence data, we used a method for pooling proportions. For hazard ratios (HR) and odds ratios (OR) of IH versus normoglycaemia, reported with 95% confidence intervals (CI), we obtained standard errors from these CIs and performed random-effects meta-analyses using the generic inverse-variance method. We used multivariable HRs and the model with the greatest number of covariates. We evaluated the certainty of the evidence with an adapted version of the GRADE framework.

MAIN RESULTS

We included 103 prospective cohort studies. The studies mainly defined IH by IFG5.6 (FPG mmol/L 5.6 to 6.9 mmol/L or 100 mg/dL to 125 mg/dL), IFG6.1 (FPG 6.1 mmol/L to 6.9 mmol/L or 110 mg/dL to 125 mg/dL), IGT (plasma glucose 7.8 mmol/L to 11.1 mmol/L or 140 mg/dL to 199 mg/dL two hours after a 75 g glucose load on the oral glucose tolerance test, combined IFG and IGT (IFG/IGT), and elevated HbA1c (HbA1c5.7: HbA1c 5.7% to 6.4% or 39 mmol/mol to 46 mmol/mol; HbA1c6.0: HbA1c 6.0% to 6.4% or 42 mmol/mol to 46 mmol/mol). The follow-up period ranged from 1 to 24 years. Ninety-three studies evaluated the overall prognosis of people with IH measured by cumulative T2DM incidence, and 52 studies evaluated glycaemic status as a prognostic factor for T2DM by comparing a cohort with IH to a cohort with normoglycaemia. Participants were of Australian, European or North American origin in 41 studies; Latin American in 7; Asian or Middle Eastern in 50; and Islanders or American Indians in 5. Six studies included children and/or adolescents.Cumulative incidence of T2DM associated with IFG5.6, IFG6.1, IGT and the combination of IFG/IGT increased with length of follow-up. Cumulative incidence was highest with IFG/IGT, followed by IGT, IFG6.1 and IFG5.6. Limited data showed a higher T2DM incidence associated with HbA1c6.0 compared to HbA1c5.7. We rated the evidence for overall prognosis as of moderate certainty because of imprecision (wide CIs in most studies). In the 47 studies reporting restitution of normoglycaemia, regression ranged from 33% to 59% within one to five years follow-up, and from 17% to 42% for 6 to 11 years of follow-up (moderate-certainty evidence).Studies evaluating the prognostic effect of IH versus normoglycaemia reported different effect measures (HRs, IRRs and ORs). Overall, the effect measures all indicated an elevated risk of T2DM at 1 to 24 years of follow-up. Taking into account the long-term follow-up of cohort studies, estimation of HRs for time-dependent events like T2DM incidence appeared most reliable. The pooled HR and the number of studies and participants for different IH definitions as compared to normoglycaemia were: IFG5.6: HR 4.32 (95% CI 2.61 to 7.12), 8 studies, 9017 participants; IFG6.1: HR 5.47 (95% CI 3.50 to 8.54), 9 studies, 2818 participants; IGT: HR 3.61 (95% CI 2.31 to 5.64), 5 studies, 4010 participants; IFG and IGT: HR 6.90 (95% CI 4.15 to 11.45), 5 studies, 1038 participants; HbA1c5.7: HR 5.55 (95% CI 2.77 to 11.12), 4 studies, 5223 participants; HbA1c6.0: HR 10.10 (95% CI 3.59 to 28.43), 6 studies, 4532 participants. In subgroup analyses, there was no clear pattern of differences between geographic regions. We downgraded the evidence for the prognostic effect of IH versus normoglycaemia to low-certainty evidence due to study limitations because many studies did not adequately adjust for confounders. Imprecision and inconsistency required further downgrading due to wide 95% CIs and wide 95% prediction intervals (sometimes ranging from negative to positive prognostic factor to outcome associations), respectively.This evidence is up to date as of 26 February 2018.

AUTHORS' CONCLUSIONS

Overall prognosis of people with IH worsened over time. T2DM cumulative incidence generally increased over the course of follow-up but varied with IH definition. Regression from IH to normoglycaemia decreased over time but was observed even after 11 years of follow-up. The risk of developing T2DM when comparing IH with normoglycaemia at baseline varied by IH definition. Taking into consideration the uncertainty of the available evidence, as well as the fluctuating stages of normoglycaemia, IH and T2DM, which may transition from one stage to another in both directions even after years of follow-up, practitioners should be careful about the potential implications of any active intervention for people 'diagnosed' with IH.

Myeloperoxidase, superoxide dismutase-3, cardiometabolic risk factors, and distal sensorimotor polyneuropathy: The KORA F4/FF4 study

BACKGROUND

Oxidative stress has been proposed as important pathomechanism of cardiometabolic diseases and distal sensorimotor polyneuropathy (DSPN). However, the relevance of biomarkers of oxidative stress has not been investigated in this context. Therefore, this study aimed to assess the association of the prooxidant myeloperoxidase (MPO) and the antioxidant extracellular superoxide dismutase (SOD3) with cardiometabolic risk factors and with prevalence and incidence of DSPN.

METHODS

Cross-sectional analyses comprised 1069 participants (40.3% with prediabetes and 20.5% with type 2 diabetes) of the population-based Cooperative Health Research in the Region of Augsburg (KORA) F4 study (2006-2008), 181 of whom had DSPN at baseline. Prospective analyses included 524 individuals without DSPN at baseline who also participated in the KORA FF4 study (2013-2014), 132 of whom developed DSPN during the 6.5-year follow-up. Serum MPO and SOD3 were measured by ELISA, and their association with cardiometabolic risk factors and DSPN were estimated by using linear and logistic regression analyses.

RESULTS

Higher MPO and SOD levels showed multiple positive associations with cardiometabolic risk factors including age, indices of obesity, insulin resistance, serum lipids, renal dysfunction, and biomarkers of inflammation. Higher MPO levels were associated with prevalent DSPN (fully adjusted OR 1.38 [95% CI 1.10; 1.72] per doubling of MPO). Higher baseline SOD3 levels were related to incident DSPN (age and sex-adjusted OR 2.14 [1.02; 4.48] per doubling of SOD3), which was partially explained by cardiometabolic risk factors.

CONCLUSIONS

Systemic levels of both pro- and antioxidant enzymes appear involved in cardiometabolic risk and development of DSPN.

Cigarette smoking as a risk factor for type 2 diabetes in women compared with men: a systematic review and meta-analysis of prospective cohort studies

Background

Few studies have investigated the effect of smoking on type 2 diabetes in women compared with men, even though several epidemiological studies provided a clear picture of the risk among the entire population.

Methods

We systematically searched PubMed and Embase up to August 2017 for prospective studies that were stratified by sex with measures of the relative risk (RR) for type 2 diabetes and current smoking compared with non-smoking. The sex-specific RRs and their ratios (RRRs), comparing women with man, were pooled using random-effects models.

Results

Seventeen articles were identified including 20 prospective cohorts with 5 077 289 participants and 223 084 incident cases of type 2 diabetes. The pooled RRR suggested a similar risk of type 2 diabetes associated with smoking in women compared with men (RRR: 0.98, 95% confidence interval [CI]: 0.96–1.01). Furthermore, no significant sex difference in the RR was found between former smokers and those who had never smoked (RRR: 0.98, 95% CI: 0.92–1.04).

Conclusions

The findings of this meta-analysis indicate that female smokers had similar risk of type 2 diabetes with male smokers.

Neuropathic pain is not adequately treated in the older general population: Results from the KORA F4 survey

PURPOSE

We evaluated the pharmacological treatment of distal sensorimotor polyneuropathy (DSPN) among older subjects from the general population.

METHODS

The study included subjects aged 61 to 82 years from the KORA F4 survey (2006-2008). DSPN was defined as the presence of bilaterally impaired foot-vibration perception and/or bilaterally impaired foot-pressure sensation. Pain intensity was assessed with the painDETECT questionnaire.

RESULTS

From the included 1076 older persons, 172 (16%) persons reported pain in the lower extremities and DSPN was present in 150 (14%) subjects. Forty-eight people with pain in the lower extremities reported DSPN. Only 38% of the subjects with DSPN reporting an average pain level of ≥4 during the past 4 weeks received medical treatment, predominantly nonsteroidal anti-inflammatory drugs (NSAIDs 20% and opioids 12%). The medication of choice for neuropathic pain, antidepressants, anticonvulsants, and opioids was relatively being underused. However, opioids and neuropathy preparations were prescribed preferably for subjects with painful DSPN.

CONCLUSIONS

In the older general population, only a small proportion of subjects with painful DSPN receive analgesic pharmacotherapy. Although not recommended by guidelines for the treatment of neuropathic pain, NSAIDs were the most frequently used class of analgesic drugs.

Regional differences in antihyperglycemic medication are not explained by individual socioeconomic status, regional deprivation, and regional health care services. Observational results from the German DIAB-CORE consortium

AIMS

This population-based study sought to extend knowledge on factors explaining regional differences in type 2 diabetes mellitus medication patterns in Germany.

METHODS

Individual baseline and follow-up data from four regional population-based German cohort studies (SHIP [northeast], CARLA [east], HNR [west], KORA [south]) conducted between 1997 and 2010 were pooled and merged with both data on regional deprivation and regional health care services. To analyze regional differences in any or newer anti-hyperglycemic medication, medication prevalence ratios (PRs) were estimated using multivariable Poisson regression models with a robust error variance adjusted gradually for individual and regional variables.

RESULTS

The study population consisted of 1,437 people aged 45 to 74 years at baseline, (corresponding to 49 to 83 years at follow-up) with self-reported type 2 diabetes. The prevalence of receiving any anti-hyperglycemic medication was 16% higher in KORA (PR 1.16 [1.08-1.25]), 10% higher in CARLA (1.10 [1.01-1.18]), and 7% higher in SHIP (PR 1.07 [1.00-1.15]) than in HNR. The prevalence of receiving newer anti-hyperglycemic medication was 49% higher in KORA (1.49 [1.09-2.05]), 41% higher in CARLA (1.41 [1.02-1.96]) and 1% higher in SHIP (1.01 [0.72-1.41]) than in HNR, respectively. After gradual adjustment for individual variables, regional deprivation and health care services, the effects only changed slightly.

CONCLUSIONS

Neither comprehensive individual factors including socioeconomic status nor regional deprivation or indicators of regional health care services were able to sufficiently explain regional differences in anti-hyperglycemic treatment in Germany. To understand the underlying causes, further research is needed.

Size and shape of the associations of glucose, HbA1c, insulin and HOMA-IR with incident type 2 diabetes: the Hoorn Study

AIMS/HYPOTHESIS

Glycaemic markers and fasting insulin are frequently measured outcomes of intervention studies. To extrapolate accurately the impact of interventions on the risk of diabetes incidence, we investigated the size and shape of the associations of fasting plasma glucose (FPG), 2 h post-load glucose (2hPG), HbA_1c, fasting insulin and HOMA-IR with incident type 2 diabetes mellitus.

METHODS

The study population included 1349 participants aged 50-75 years without diabetes at baseline (1989) from a population-based cohort in Hoorn, the Netherlands. Incident type 2 diabetes was defined by the WHO 2011 criteria or known diabetes at follow-up. Logistic regression models were used to determine the associations of the glycaemic markers, fasting insulin and HOMA-IR with incident type 2 diabetes. Restricted cubic spline logistic regressions were conducted to investigate the shape of the associations.

RESULTS

After a mean follow-up duration of 6.4 (SD 0.5) years, 152 participants developed diabetes (11.3%); the majority were screen detected by high FPG. In multivariate adjusted models, ORs (95% CI) for incident type 2 diabetes for the highest quintile in comparison with the lowest quintile were 9.0 (4.4, 18.5) for FPG, 6.1 (2.9, 12.7) for 2hPG, 3.8 (2.0, 7.2) for HbA_1c, 1.9 (0.9, 3.6) for fasting insulin and 2.8 (1.4, 5.6) for HOMA-IR. The associations of FPG and HbA_1c with incident diabetes were non-linear, rising more steeply at higher values.

CONCLUSIONS/INTERPRETATION

FPG was most strongly associated with incident diabetes, followed by 2hPG, HbA_1c, HOMA-IR and fasting insulin. The strong association with FPG is probably because FPG is the most frequent marker for diabetes diagnosis. Non-linearity of associations between glycaemic markers and incident type 2 diabetes should be taken into account when estimating future risk of type 2 diabetes based on glycaemic markers.