Publications

190 Publications visible to you, out of a total of 190

Abstract (Expand)

The genetic basis of sleep is still poorly understood. Despite the moderate to high heritability of sleep-related phenotypes, known genetic variants explain only a small proportion of the phenotypical variance. However, most previous studies were based solely upon self-report measures. The present study aimed to conduct the first genome-wide association (GWA) of actigraphic sleep phenotypes. The analyses included 956 middle- to older-aged subjects (40-79 years) from the LIFE Adult Study. The SenseWear Pro 3 Armband was used to collect 11 actigraphic parameters of night- and daytime sleep and three parameters of rest (lying down). The parameters comprised measures of sleep timing, quantity and quality. A total of 7 141 204 single nucleotide polymorphisms (SNPs) were analysed after imputation and quality control. We identified several variants below the significance threshold of P </= 5x 10(-8) (not corrected for analysis of multiple traits). The most significant was a hit near UFL1 associated with sleep efficiency on weekdays (P = 1.39 x 10(-8) ). Further SNPs were close to significance, including an association between sleep latency and a variant in CSNK2A1 (P = 8.20 x 10(-8) ), a gene known to be involved in the regulation of circadian rhythm. In summary, our GWAS identified novel candidate genes with biological plausibility being promising candidates for replication and further follow-up studies.

Authors: J. Spada, M. Scholz, H. Kirsten, T. Hensch, K. Horn, P. Jawinski, C. Ulke, R. Burkhardt, K. Wirkner, M. Loeffler, U. Hegerl, C. Sander

Date Published: 30th Apr 2016

Publication Type: Journal article

Abstract (Expand)

BACKGROUND: Histologically, follicular lymphoma (FL) grades 1, 2 and 3A are composed of two distinct cell types, centroblasts and centrocytes. FL grade 3B is composed only of centroblasts and has been shown to differ in immunophenotype and genetics from FL that contain centrocytes. We aimed to understand the pathogenetic and clinical relation between FL grade 3A to FL grade 1/2 on the one hand and FL grade 3B on the other hand. PATIENTS AND METHODS: Trial patients with long-term follow-up and diagnosis of FL grade 3 were selected and samples underwent a second central pathological review using a multiple-observer approach to assess grading. RESULTS: Interobserver variability for diagnosing FL grade 3 was high. FL grade 3A frequently harbored areas of FL grade 1/2 within the same tissue specimen. FL grade 3B rarely coexisted with grade 1/2 or 3A, suggesting divergent pathogenesis. There was no statistically significant difference in outcome between 47 cases of FL grade 3A and 14 cases of grade 3B. Compared with grade 1/2 FL, both groups showed longer progression-free survival without late events, especially after immunochemotherapy; this outcome difference was retained after adjustment for clinical prognostic factors. The subgroup of FL grade 3A with an additional FL grade 1/2 component or a translocation t(14;18) showed a poorer outcome. In contrast, the FL grade 3A lacking t(14;18) and of localized stage resembled the pediatric type of FL and showed a very good outcome. FL3 with MYC breaks showed a poor outcome. CONCLUSIONS: The results suggest that first-line immunochemotherapy might allow long-lasting remissions in a subgroup of FL grade 3A similar to diffuse large B-cell lymphoma. Within FL3A, prognostic subgroups can be identified by analyzing for coexisting FL1/2 and MYC breaks.

Authors: K. Koch, E. Hoster, M. Ziepert, M. Unterhalt, G. Ott, A. Rosenwald, M. L. Hansmann, W. Bernd, H. Stein, V. Poschel, M. Dreyling, L. Trumper, M. Loffler, N. Schmitz, W. Hiddemann, M. Pfreundschuh, W. Klapper

Date Published: 28th Apr 2016

Publication Type: Not specified

Human Diseases: follicular lymphoma

Abstract (Expand)

Pulse wave velocity (PWV) and augmentation index (AI) are independent predictors of cardiovascular health. However, the comparability of multiple oscillometric modalities currently available for their assessment was not studied in detail. In the present study, we aimed to evaluate the relationship between indices of arterial stiffness assessed by diastolic and suprasystolic oscillometry.In total, 56 volunteers from the general population (23 males; median age 70 years [interquartile range: 65-72 years]) were recruited into observational feasibility study to evaluate the carotid-femoral/aortic PWV (cf/aoPWV), brachial-ankle PWV (baPWV), and AI assessed by 2 devices: Vicorder (VI) applying diastolic, right-sided oscillometry for the determination of all 3 indices, and Vascular explorer (VE) implementing single-point, suprasystolic brachial oscillometry (SSBO) pulse wave analysis for the assessment of cfPWV and AI. Within- and between-device correlations of measured parameters were analyzed. Furthermore, agreement of repeated measurements, intra- and inter-observer concordances were determined and compared for both devices.In VI, both baPWV and cfPWV inter-correlated well and showed good level of agreement with bilateral baPWV measured by VE (baPWV[VI]-baPWV[VE]R: overall concordance correlation coefficient [OCCC] = 0.484, mean difference = 1.94 m/s; cfPWV[VI]-baPWV[VE]R: OCCC = 0.493, mean difference = 1.0 m/s). In contrast, SSBO-derived aortic PWA (cf/aoPWA[VE]) displayed only weak correlation with cfPWV(VI) (r = 0.196; P = 0.04) and ipsilateral baPWV (cf/aoPWV[VE]R-baPWV[VE]R: r = 0.166; P = 0.08). cf/aoPWA(VE) correlated strongly with AI(VE) (right-sided: r = 0.725, P < 0.001). AI exhibited marginal between-device agreement (right-sided: OCCC = 0.298, mean difference: 6.12%). All considered parameters showed good-to-excellent repeatability giving OCCC > 0.9 for 2-point-PWV modes and right-sided AI(VE). Intra- and inter-observer concordances were similarly high except for AI yielding a trend toward better reproducibility in VE (interobserver-OCCC[VI] vs [VE] = 0.774 vs 0.844; intraobserver-OCCC[VI] vs [VE] = 0.613 vs 0.769).Both diastolic oscillometry-derived PWV modes, and AI measured either with VI or VE, are comparable and reliable alternatives for the assessment of arterial stiffness. Aortic PWV assessed by SSBO in VE is not related to the corresponding indices determined by traditional diastolic oscillometry.

Authors: A. Teren, F. Beutner, K. Wirkner, M. Loffler, M. Scholz

Date Published: 11th Mar 2016

Publication Type: Journal article

Abstract (Expand)

Stratification of head and neck squamous cell carcinomas (HNSCC) based on HPV16 DNA and RNA status, gene expression patterns, and mutated candidate genes may facilitate patient treatment decision. We characterize head and neck squamous cell carcinomas (HNSCC) with different HPV16 DNA and RNA (E6*I) status from 290 consecutively recruited patients by gene expression profiling and targeted sequencing of 50 genes. We show that tumors with transcriptionally inactive HPV16 (DNA+ RNA-) are similar to HPV-negative (DNA-) tumors regarding gene expression and frequency of TP53 mutations (47%, 8/17 and 43%, 72/167, respectively). We also find that an immune response-related gene expression cluster is associated with lymph node metastasis, independent of HPV16 status and that disruptive TP53 mutations are associated with lymph node metastasis in HPV16 DNA- tumors. We validate each of these associations in another large data set. Four gene expression clusters which we identify differ moderately but significantly in overall survival. Our findings underscore the importance of measuring the HPV16 RNA (E6*I) and TP53-mutation status for patient stratification and identify associations of an immune response-related gene expression cluster and TP53 mutations with lymph node metastasis in HNSCC.

Authors: G. Wichmann, M. Rosolowski, K. Krohn, M. Kreuz, A. Boehm, A. Reiche, U. Scharrer, D. Halama, J. Bertolini, U. Bauer, D. Holzinger, M. Pawlita, J. Hess, C. Engel, D. Hasenclever, M. Scholz, P. Ahnert, H. Kirsten, A. Hemprich, C. Wittekind, O. Herbarth, F. Horn, A. Dietz, M. Loeffler

Date Published: 15th Dec 2015

Publication Type: Not specified

Human Diseases: head and neck cancer

Abstract (Expand)

BACKGROUND: Cardiorespiratory fitness is a well-established independent predictor of cardiovascular health. However, the relevance of alternative exercise and non-exercise tests for cardiorespiratory fitness assessment in large cohorts has not been studied in detail. We aimed to evaluate the YMCA-step test and the Veterans Specific Activity Questionnaire (VSAQ) for the estimation of cardiorespiratory fitness in the general population. METHODS: One hundred and five subjects answered the VSAQ, performed the YMCA-step test and a maximal cardiopulmonary exercise test (CPX) and gave BORG ratings for both exercise tests (BORGSTEP, BORGCPX). Correlations of peak oxygen uptake on a treadmill (VO2_PEAK) with VSAQ, BORGSTEP, one-minute, post-exercise heartbeat count, and peak oxygen uptake during the step test (VO2_STEP) were determined. Moreover, the incremental values of the questionnaire and the step test in addition to other fitness-related parameters were evaluated using block-wise hierarchical regression analysis. RESULTS: Eighty-six subjects completed the step test according to the protocol. For completers, correlations of VO2_PEAK with the age- and gender-adjusted VSAQ, heartbeat count and VO2_STEP were 0.67, 0.63 and 0.49, respectively. However, using hierarchical regression analysis, age, gender and body mass index already explained 68.8% of the variance of VO2_PEAK, while the additional benefit of VSAQ was rather low (3.4%). The inclusion of BORGSTEP, heartbeat count and VO2_STEP increased R(2) by a further 2.2%, 3.3% and 5.6%, respectively, yielding a total R(2) of 83.3%. CONCLUSIONS: Neither VSAQ nor the YMCA-step test contributes sufficiently to the assessment of cardiorespiratory fitness in population-based studies.

Authors: A. Teren, S. Zachariae, F. Beutner, R. Ubrich, M. Sandri, C. Engel, M. Loffler, S. Gielen

Date Published: 15th Dec 2015

Publication Type: Not specified

Abstract (Expand)

Genetics of gene expression (eQTLs or expression QTLs) has proved an indispensable tool for understanding biological pathways and pathomechanisms of trait-associated SNPs. However, power of most genome-wide eQTL studies is still limited. We performed a large eQTL study in peripheral blood mononuclear cells of 2112 individuals increasing the power to detect trans-effects genome-wide. Going beyond univariate SNP-transcript associations, we analyse relations of eQTLs to biological pathways, polygenetic effects of expression regulation, trans-clusters and enrichment of co-localized functional elements. We found eQTLs for about 85% of analysed genes, and 18% of genes were trans-regulated. Local eSNPs were enriched up to a distance of 5 Mb to the transcript challenging typically implemented ranges of cis-regulations. Pathway enrichment within regulated genes of GWAS-related eSNPs supported functional relevance of identified eQTLs. We demonstrate that nearest genes of GWAS-SNPs might frequently be misleading functional candidates. We identified novel trans-clusters of potential functional relevance for GWAS-SNPs of several phenotypes including obesity-related traits, HDL-cholesterol levels and haematological phenotypes. We used chromatin immunoprecipitation data for demonstrating biological effects. Yet, we show for strongly heritable transcripts that still little trans-chromosomal heritability is explained by all identified trans-eSNPs; however, our data suggest that most cis-heritability of these transcripts seems explained. Dissection of co-localized functional elements indicated a prominent role of SNPs in loci of pseudogenes and non-coding RNAs for the regulation of coding genes. In summary, our study substantially increases the catalogue of human eQTLs and improves our understanding of the complex genetic regulation of gene expression, pathways and disease-related processes.

Authors: H. Kirsten, H. Al-Hasani, L. Holdt, A. Gross, F. Beutner, K. Krohn, K. Horn, P. Ahnert, R. Burkhardt, K. Reiche, J. Hackermuller, M. Loffler, D. Teupser, J. Thiery, M. Scholz

Date Published: 15th Aug 2015

Publication Type: Journal article

Abstract (Expand)

The Three-Factor-Eating-Questionnaire (TFEQ) is an established instrument to assess eating behaviour. Analysis of the TFEQ-factor structure was based on selected, convenient and clinical samples so far. Aims of this study were (I) to analyse the factor structure of the German version of the TFEQ and (II)--based on the refined factor structure--to examine the association between eating behaviour and the body mass index (BMI) in a general population sample of 3,144 middle-aged and older participants (40-79 years) of the ongoing population based cohort study of the Leipzig Research Center for Civilization Diseases (LIFE Health Study). The factor structure was examined in a split-half analysis with both explorative and confirmatory factor analysis. Associations between TFEQ-scores and BMI values were tested with multiple regression analyses controlled for age, gender, and education. We found a three factor solution for the TFEQ with an 'uncontrolled eating', a 'cognitive restraint' and an 'emotional eating' domain including 29 of the original 51 TFEQ-items. Scores of the 'uncontrolled eating domain' showed the strongest correlation with BMI values (partial r = 0.26). Subjects with scores above the median in both 'uncontrolled eating' and 'emotional eating' showed the highest BMI values (mean = 29.41 kg/m(2)), subjects with scores below the median in all three domains showed the lowest BMI values (mean = 25.68 kg/m(2); F = 72.074, p<0.001). Our findings suggest that the TFEQ is suitable to identify subjects with specific patterns of eating behaviour that are associated with higher BMI values. Such information may help health care professionals to develop and implement more tailored interventions for overweight and obese individuals.

Authors: A. Loffler, T. Luck, F. S. Then, C. Sikorski, P. Kovacs, Y. Bottcher, J. Breitfeld, A. Tonjes, A. Horstmann, M. Loffler, C. Engel, J. Thiery, A. Villringer, M. Stumvoll, S. G. Riedel-Heller

Date Published: 1st Aug 2015

Publication Type: Not specified

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