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142 Publications visible to you, out of a total of 142
Normative values of the Epworth Sleepiness Scale (ESS), derived from a large German sample.
LIFE Adult

Abstract (Expand)

PURPOSE: Daytime sleepiness is associated with several medical problems. The aim of this paper is to provide normative values for one of the most often used questionnaires measuring daytime sleepiness, … the Epworth Sleepiness Scale (ESS). METHODS: A large sample of 9711 people from the German general population took part in this study. In addition to the ESS, several other questionnaires were used, and sociodemographic and behavioral factors were recorded. RESULTS: Normative values for the ESS are given. According to the generally accepted criterion ESS > 10, 23 % of the sample showed excessive daytime sleepiness. Males reported significantly more daytime sleepiness than females (effect size d = 0.19). In the age range of 40-80 years, a continuous decline of daytime sleepiness was observed. Psychometric properties of the ESS were good. Alcohol intake and nicotine consumption were marginally associated with daytime sleepiness, and obese people reported significantly more sleepiness than people of normal weight (OR = 1.39). CONCLUSIONS: The normative tables allow clinicians and researchers to assess the degree of their patients' daytime sleepiness, especially in the upper range of scores.

Authors: C. Sander, U. Hegerl, K. Wirkner, N. Walter, R. D. Kocalevent, K. Petrowski, H. Glaesmer, A. Hinz

Date Published: 29th May 2016

Publication Type: Journal article

Optimization-Based Speckle Tracking Algorithm for Left Ventricle Strain Estimation: A Feasibility Study.
LIFE Adult

Abstract (Expand)

Speckle tracking echocardiography (STE) is a widespread method for calculating myocardial strains and estimating left ventricle function. Since echocardiographic clips are corrupted by speckle decorrelation … noise, resulting in irregular, nonphysiological tissue displacement fields, smoothing is performed on the displacement data, affecting the strain results. Thus, strain results may depend on the specific implementations of 2-D STE, as well as other systems' characteristics of the various vendors. A novel algorithm (called K-SAD) is introduced, which integrates the physiological constraint of smoothness of the displacement field into an optimization process. Simulated B-mode clips, modeling healthy and abnormal cases, were processed by K-SAD. Peak global and subendocardial longitudinal strains, as well as regional strains, were calculated. In addition, 410 healthy subjects were also processed. The results of K-SAD are compared with those of one of the leading commercial product. K-SAD provides global mid-wall strain values, as well as subendocardial and regional strain values, all in good agreement with the ground-truth-simulated phantom data. K-SAD peak global longitudinal systolic strain values for 410 healthy subjects are quite similar for the different regions: - 17.02 +/- 4.02%, - 19.00 +/- 3.45%, and - 19.72 +/- 5.06% at the basal, mid, and apical regions, respectively. Improved performance under noisy conditions was demonstrated by comparing a subgroup of 40 subjects with the best image quality with the remaining 370 cohort: K-SAD provides statistically similar global and regional results for the two cohorts. Our study indicates that the sensitivity of strain values to speckle noise, caused by the post block-matching weighted smoothing, can be significantly reduced and accuracy enhanced by employing an integrated one-stage, physiologically constrained optimization process.

Authors: H. Khamis, S. Shimoni, A. Hagendorff, N. Smirin, Z. Friedman, D. Adam

Date Published: 24th May 2016

Publication Type: Journal article

Neural processing of negative emotional stimuli and the influence of age, sex and task-related characteristics.
LIFE Adult

Abstract (Expand)

Negative emotional stimuli are particularly salient events that receive privileged access to neurocognitive resources. At the neural level, the processing of negative stimuli relies on a set of sensory, … limbic, and prefrontal areas. However, controversies exist on how demographic and task-related characteristics modulate this brain pattern. Here, we used activation likelihood estimation (ALE) meta-analysis and replicator dynamics to investigate the processing of negative visual stimuli in healthy adults. Our findings endorse the central role of the amygdala. This result might reflect how this structure modulates perceptual and attentional mechanisms in response to emotional stimuli. Additionally, we characterize how the neural processing of negative visual stimuli is influenced by the demographic factors of age and sex as well as by task-related characteristics like stimulus type, emotion category, and task instruction, with the amygdala showing comparable engagement across different sexes, stimulus types, and task instructions. Our findings practically inform experimentation in the affective neurosciences but also suggest brain circuits for neurobiological investigations of affective symptomatology.

Authors: I. Garcia-Garcia, J. Kube, M. Gaebler, A. Horstmann, A. Villringer, J. Neumann

Date Published: 12th May 2016

Publication Type: Not specified

Time to wake up: No impact of COMT Val158Met gene variation on circadian preferences, arousal regulation and sleep.
LIFE Adult, Genetical Statistics and Systems Biology

Abstract (Expand)

Dopamine has been implicated in the regulation of sleep-wake states and the circadian rhythm. However, there is no consensus on the impact of two established dopaminergic gene variants: the … catechol-O-methyltransferase Val158Met (COMT Val158Met; rs4680) and the dopamine D4 receptor Exon III variable-number-of-tandem-repeat polymorphism (DRD4 VNTR). Pursuing a multi-method approach, we examined their potential effects on circadian preferences, arousal regulation and sleep. Subjects underwent a 7-day actigraphy assessment (SenseWear Pro3), a 20-minute resting EEG (analyzed using VIGALL 2.0) and a body mass index (BMI) assessment. Further, they completed the Morningness-Eveningness Questionnaire (MEQ), the Epworth Sleepiness Scale (ESS) and the Pittsburgh Sleep Quality Index (PSQI). The sample comprised 4625 subjects (19-82 years) genotyped for COMT Val158Met, and 689 elderly subjects (64-82 years) genotyped for DRD4 VNTR. The number of subjects varied across phenotypes. Power calculations revealed a minimum required phenotypic variance explained by genotype ranging between 0.5% and 1.5% for COMT Val158Met and between 3.3% and 6.0% for DRD4 VNTR. Analyses did not reveal significant genotype effects on MEQ, ESS, PSQI, BMI, actigraphy and EEG variables. Additionally, we found no compelling evidence in sex- and age-stratified subsamples. Few associations surpassed the threshold of nominal significance (p < .05), providing some indication for a link between DRD4 VNTR and daytime sleepiness. Taken together, in light of the statistical power obtained in the present study, our data particularly suggest no impact of the COMT Val158Met polymorphism on circadian preferences, arousal regulation and sleep. The suggestive link between DRD4 VNTR and daytime sleepiness, on the other hand, might be worth investigation in a sample enriched with younger adults.

Authors: P. Jawinski, S. Tegelkamp, C. Sander, M. Hantzsch, J. Huang, N. Mauche, M. Scholz, J. Spada, C. Ulke, R. Burkhardt, A. Reif, U. Hegerl, T. Hensch

Date Published: 6th May 2016

Publication Type: Not specified

Genome-wide association analysis of actigraphic sleep phenotypes in the LIFE Adult Study.
LIFE Adult, Genetical Statistics and Systems Biology

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

Education as protector against dementia, but what exactly do we mean by education?
LIFE Adult

Abstract (Expand)

OBJECTIVES: even though a great number of research studies have shown that high education has protective effects against dementia, some studies did not observe such a significant effect. In that respect, … the aim of our study was to investigate and compare various operationalisation approaches of education and how they impact dementia risk within one sample. METHODS: data were derived from the Leipzig longitudinal study of the aged (LEILA75+). Individuals aged 75 and older underwent six cognitive assessments at an interval of 1.5 years and a final follow-up 15 years after the baseline assessment. We operationalised education according to different approaches used in previous studies and analysed the impact on dementia incidence via multivariate cox regression modelling. RESULTS: the results showed that whether education is identified as significant protector against dementia strongly depends on the operationalisation of education. Whereas the pure number of years of education showed statistically significant protective effects on dementia risk, other more complex categorical classification approaches did not. Moreover, completing >10 years of education or a tertiary level seems to be an important threshold to significantly reduce dementia risk. CONCLUSION: findings suggest a protective effect of more years of education on a lower dementia risk with a particular critical threshold of completing >10 years of education. Further, the findings highlight that, when examining risks and protective factors of dementia, a careful consideration of the underlying definitions and operationalisation approaches is required.

Authors: F. S. Then, T. Luck, M. C. Angermeyer, S. G. Riedel-Heller

Date Published: 9th Apr 2016

Publication Type: Journal article

Human Diseases: dementia

Tobacco use is associated with reduced amplitude and intensity dependence of the cortical auditory evoked N1-P2 component.
LIFE Adult

Abstract (Expand)

RATIONALE: Tobacco use is linked to cerebral atrophy and reduced cognitive performance in later life. However, smoking-related long-term effects on brain function remain largely uncertain. Previous … studies suggest that nicotine affects serotonergic signaling, and the intensity dependence (alias loudness dependence) of the auditory evoked N1-P2 potential has been proposed as a marker of serotonergic neurotransmission. OBJECTIVE: In the present study, we assesed the effects of chronic smoking on amplitude and intensity dependence of the auditory evoked N1-P2 potential. METHODS: Subjects underwent a 15-min intensity dependence of auditory evoked potentials (IAEP) paradigm. From N = 1739 eligible subjects (40-79 years), we systematically matched current smokers, ex-smokers, and never-smokers by sex, age, alcohol and caffeine consumption, and socioeconomic status. Between-group differences and potential dose-dependencies were evaluated. RESULTS: Analyses revealed higher N1-P2 amplitudes and intensity dependencies in never-smokers relative to ex- and current smokers, with ex-smokers exhibiting intermediate intensity dependencies. Moreover, we observed pack years and number of cigarettes consumed per day to be inversely correlated with amplitudes in current smokers. CONCLUSIONS: According to the IAEP serotonin hypothesis, our results suggest serotonin activity to be highest in current smokers, intermediate in ex-smokers, and lowest in never-smokers. To our knowledge, the present study is the first providing evidence for a dose-dependent reduction in N1-P2 amplitudes. Further, we extend prior research by showing reduced amplitudes and intensity dependencies in ex-smokers even 25 years, on average, after cessation. While we can rule out several smoking-related confounders to bias observed associations, causal inferences remain to be established by future longitudinal studies.

Authors: P. Jawinski, N. Mauche, C. Ulke, J. Huang, J. Spada, C. Enzenbach, C. Sander, U. Hegerl, T. Hensch

Date Published: 18th Mar 2016

Publication Type: Not specified

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