Long-Term Follow-Up of HRQoL up to Six Years after Outpatient Phase-II Cardiac Rehabilitation

Background: Low health-related quality of life (HRQoL) is associated with adverse cardiovascular outcomes in coronary heart disease (CHD) patients. Cardiac rehabilitation (CR) improves HRQoL; however, evidence on long-term HRQoL changes after CR, and their predictors, is missing. Methods: A total of 153 patients with complete HRQoL data in the short-form (SF)-36 Health Survey at CR entry, discharge and follow-up were included. Using linear mixed-effects regression models for repeated time measurements, we examined predictors of follow-up HRQoL, including age and clinical characteristics. Results: Both physical (t = -5.66, p < 0.001) and mental (t = -2.06, p = 0.040) HRQoL improved significantly from CR entry to discharge, with improvements remaining stable over a mean follow-up of four years (range 2.4-6.1). Better functional capacity (6MWT) at CR entry predicted better physical HRQoL (t = 5.50, p < 0.001) and, with a trend, better mental HRQoL (t = 1.92, p = 0.056) at follow-up. A psychiatric diagnosis at CR entry predicted better mental HRQoL at follow-up (t = 3.85, p < 0.001). Conclusions: Improvements in HRQoL during CR remain stable during long-term follow-up. Levels of functional capacity appear to be relevant to both physical and mental HRQoL at follow-up.

Differential associations of sex and age with changes in HRQoL during outpatient cardiac rehabilitation

INTRODUCTION

Cardiovascular diseases (CVD) represent the world's leading cause of death. Health-related quality of life (HRQoL) is a widely applied concept of patients' perceived health and is directly linked to CVD morbidity, mortality, and re-hospitalization rates. Cardiac rehabilitation (CR) improves both cardiovascular outcomes and HRQoL. Regrettably, CR is still underutilized, especially in subgroups like women and elderly patients. The aim of our study was to investigate the predictive potential of sex and age on change of HRQoL throughout outpatient CR.

METHODS

497 patients of outpatient CR were retrospectively assessed from August 2015 to September 2019 at the University Hospital Zurich. A final sample of 153 individuals with full HRQoL data both at CR entry and discharge was analyzed. HRQoL was measured using the 36-Item Short Form Survey (SF-36) with its physical (PCS) and mental (MCS) component scale. In two-factorial analyses of variance, we analyzed sex- and age-specific changes in HRQoL scores throughout CR, adjusting for psychosocial and clinical characteristics. Age was grouped into participants over and under the age of 65.

RESULTS

In both sexes, mean scores of physical HRQoL improved significantly during CR (p <.001), while mean scores of mental HRQoL improved significantly in men only (p =.003). Women under the age of 65 had significantly greater physical HRQoL improvements throughout CR, compared with men under 65 (p =.043) and women over 65 years of age (p =.014). Sex and age did not predict changes in mental HRQoL throughout CR.

CONCLUSIONS

Younger women in particular benefit from CR with regard to their physical HRQoL. Among older participants, women report equal improvements of physical HRQoL than men. Our results indicate that sex- and age-related aspects of HRQoL outcomes should be considered in CR.

Predictors of gain in exercise capacity through cardiac rehabilitation: Sex and age matter

BACKGROUND

Cardiac rehabilitation (CR) is a cornerstone of secondary prevention that improves cardiovascular outcomes. However, the determinants of treatment success are poorly understood.

OBJECTIVES

We investigated the associations of health-related quality of life (HRQoL), sex, age, employment status and housing situation with improvement in exercise capacity throughout CR.

METHODS

We analyzed data from 392 CR outpatients (81% men and 19% women). Exercise capacity at baseline and upon completion of the program was measured with the 6-minute walk distance (6MWD). HRQoL at CR entry was assessed with the Short Form 36 Health Survey (SF-36).

RESULTS

A multivariable regression analysis revealed that both men and women showed significant improvement in exercise capacity (p < .001). Female sex (B = 18.118, 95% CI 0.341 - 36.035, p = .046) and younger age (B = -0.887, 95% CI -1.463 - -0.312, p = .003) emerged as predictors of greater improvement, while HRQoL, employment status, and housing situation were not associated with significant change in exercise capacity. The final model explained 25% of the variance in exercise capacity change (adjusted R2 = 0.25, p < .001).

CONCLUSIONS

Our results indicate that women and younger participants benefit from CR by improving their exercise capacity. Employment status, housing situation and HRQoL showed no effects on CR outcome.

Underutilization of effective coping styles in male physicians with burnout

Ineffective coping is a risk factor for burnout among physicians, in whom the prevalence of burnout is high and has also increased in recent years. We examined in a cross-sectional study whether physicians with burnout show different coping styles compared with healthy controls. Male physicians (n = 60) were recruited into two groups (burnout vs. healthy). The Coping Inventory for Stressful Situations (CISS) and the Maslach Burnout Inventory (MBI) were applied. Wilcoxon rank-sum test showed group differences in two of the three coping styles, task-oriented and emotion-oriented, and also in one of the two subscales of the avoidance-oriented coping: social-diversion-oriented coping. Multiple binomial logistic regression, controlling for age, showed that lower task-oriented coping (OR = 0.38 (0.13 - 0.93), p = 0.048, d = 0.534) and lower social-diversion-oriented coping (OR = 0.33 (0.11 - 0.80), p = 0.024, d = 0.611) significantly predicted the burnout group. The findings suggest that male physicians with burnout differ from healthy controls in terms of less frequent utilization of effective coping styles. These findings could be explored for their utility in preventing burnout in future studies.

Association of positive psychological well-being with circulating inflammatory markers: A systematic review and meta-analysis

Accumulating evidence shows a protective effect of positive psychological well-being (PPWB) on health outcomes. However, the underlying mechanisms remain poorly understood. One pathway relates to enhanced immune functioning (Boehm, 2021). The aim of this project was to conduct a systematic review and meta-analysis of the association between PPWB and circulating inflammatory biomarkers and determine the magnitude of this association. After examining 748 references, 29 studies were included. Results from over 94'700 participants revealed a significant association between PPWB and reduced levels of interleukin (IL)-6 (r=-0.05; P<.001) and C-reactive protein (CRP) (r=-0.06; P<.001) with a heterogeneity of I² = 31.5% and I² = 84.5%, respectively. Only the association of PPWB with CRP was independent of co-variates included in the individual studies (r=-0.04; P=.027),. The findings of this systematic review and meta-analysis suggest that PPWB is associated with lower levels of inflammatory biomarkers IL-6 and CRP in the circulation. Such relationships with inflammatory biomarkers may partly explain positive effects of PPWB on health.

Sex and age as predictors of health-related quality of life change in Phase II cardiac rehabilitation

AIMS

Cardiac rehabilitation (CR) not only improves cardiovascular outcomes, but also health-related quality of life (HRQOL). Unfortunately, CR is still underutilized, especially among women and older patients. Aim of this study was to highlight age- and sex-specific effects of inpatient CR on HRQOL.

METHODS AND RESULTS

From 2012 to 2018, 18 459 patients were prospectively assessed in six Swiss CR clinics. Of these, we retrospectively analysed a final sample of 8286 patients with a mean (standard deviation) age of 67.8 (11.3) in men and 72.2 (11.3) in women. HRQOL was measured at CR entry and discharge. In multivariable analyses, sex- and age-specific changes in HRQOL throughout CR were estimated, adjusting for baseline HRQOL and clinical characteristics. Participants of both sexes improved significantly (P < 0.001) in all domains of HRQOL during CR. Women reported significantly lower social (P < 0.001) and emotional (P < 0.001) HRQOL than men at CR entry. Female sex predicted greater improvement in social (F = 19.63, P < 0.001), emotional (F = 27.814, P < 0.001), and physical HRQOL (F = 20.473, P < 0.001). In a subgroup of n = 2632 elderly patients (>75 years), female sex predicted greater changes in emotional (F = 15.738, P < 0.001) and physical (F = 6.295, P = 0.012), but not in social HRQOL.

CONCLUSION

Women report poorer HRQOL at CR entry compared with men, but in turn particularly benefit from CR in this regard. Our results indicate that sex- and age-specific needs of patients should be considered.

Differential associations of emotional and physical domains of the MacNew Heart with changes in 6-min walking test

AIMS

Cardiac rehabilitation (CR), a key component of secondary prevention in cardiac patients, contributes fundamentally to improved cardiovascular health outcomes. Health-related quality of life (HRQOL) represents a widely employed outcome measure in CR, yet, its predictive properties on exercise capacity change during CR are poorly understood. Aim of this study was to examine the association between baseline HRQOL and its subdomains on improvement of exercise capacity during CR.

METHODS

Study participants were 13,717 inpatients of six Swiss CR clinics from 2012 to 2018. We measured HRQOL at admission to CR with the MacNew Heart (MNH) questionnaire and exercise capacity at admission and discharge using the six minutes walking test (6MWT). Following factorial analyses, we performed univariate and multivariate analyses to test the predictive properties of baseline global HRQOL and its domains for improvement in exercise capacity, adjusting for demographic and clinical characteristics.

RESULTS

Mean improvement in 6MWT was 114 m (SD = 90), achieved after 17.4 days (SD = 5.5). Lower emotional HRQOL (b = 7.85, p =  < .001, 95% CI [- 5.67, 10.03]) and higher physical HRQOL (b =  - 5.23, p < .001, 95% CI [- 6.56, - 3.90]) were associated with less improvement in the 6MWT. Global MNH and social HRQOL showed no association with exercise capacity improvement.

CONCLUSION

Patients entering CR with low emotional and high physical HRQOL are at risk for a lower gain in exercise capacity during CR. Global MNH alone does not provide a reliable assessment of HRQOL; thus a focus on specific domains of HRQOL is needed.

Differential associations of emotional and physical domains of the MacNew Heart with changes in 6-minute walking test

Aims

Cardiac rehabilitation (CR), a key component of secondary prevention in cardiac patients, contributes fundamentally to improved cardiovascular health outcomes. Health-related quality of life (HRQOL) represents a widely employed outcome measure in CR, yet, its predictive properties on exercise capacity change during CR are poorly understood. Aim of this study was to examine the association between baseline HRQOL and its subdomains on improvement of exercise capacity during CR.

Methods

Study participants were 13,717 inpatients of six Swiss CR clinics from 2012 to 2018. We measured HRQOL at admission to CR with the MacNew Heart (MNH) questionnaire and exercise capacity at admission and discharge using the six-minutes walking test (6MWT). Following factorial analyses, we performed univariate and multivariate analyses to test the predictive properties of baseline global HRQOL and its domains for improvement in exercise capacity, adjusting for demographic and clinical characteristics.

Results

Mean improvement in 6MWT was 114 meters (SD=90), achieved after 17.4 days (SD=5.5). Lower emotional HRQOL (b=7.85, p≤0.001, 95% CI [−5.67, 10.03]) and higher physical HRQOL (b=−5.23, p&lt;0.001, 95% CI [−6.56, −3.90]) were associated with less improvement in the 6MWT. Global MNH and social HRQOL showed no association with exercise capacity improvement.

Conclusion

Patients entering CR with low emotional and high physical HRQOL are at risk for a lower gain in exercise capacity during CR. Global MNH alone does not provide a reliable assessment of HRQOL; thus a focus on specific domains of HRQOL is needed.

Funding Acknowledgement

Type of funding sources: None.

Sex- and age-related differences of HRQOL change in cardiac rehabilitation

Introduction

Health-related quality of life (HRQOL) has emerged as a valid and disease-specific outcome measure in cardiac patients. Cardiac rehabilitation (CR), a core component of secondary prevention, not only improves cardiovascular outcomes, but also HRQOL. Unfortunately, CR is still underutilized, especially among women and older patients. Aim of this study was to highlight age- and sex-specific effects of CR on HRQOL.

Method

A sample of 8286 patients (mean age 69.2±11.47 years; men 67.8±11.29, women 72.2±11.25) was analyzed. Patients were prospectively asessed from 2012 to 2018 in six Swiss CR clinics. HRQOL was measured at CR entry and discharge using the MacNew Heart Disease questionnaire. In multivariate analyses, we estimated sex- and age-specific changes in HRQOL during CR, adjusting for clinical characteristics.

Results

Women scored lower in any subdomain of HRQOL on admission to CR (social M = 5.05 (SD = 1.3); emotional M = 5.06±1.17; physical M = 4.36±1.72), compared to men (social M = 5.2±1.23); emotional M = 5.35±1.1; physical M = 4.43±1.76). Women showed greater improvement of social (F=10.98, p&lt;0.001), emotional (F=17.73, p&lt;0.001) and physical HRQOL (F=9.47, p=0.002). In a subgroup of elderly patients (&gt;76 years) female sex predicted higher changes in emotional (F=10.878, p&lt;0.001), but not in social (F=1.424, p=0.232) and physical HRQOL (F=2.272, p=0.132).

Conclusion

Women report poorer HRQOL in all subdomains at CR entry compared to men, but in turn particularly benefit from CR in this regard. In older patients, this is particularly true for emotional HRQOL. Our results indicate that sex- and age-specific needs of cardiac patients should be considered during CR.

Funding Acknowledgement

Type of funding sources: None.

Depressive Symptoms Predict Clinical Recurrence of Inflammatory Bowel Disease

BACKGROUND

Inflammatory bowel disease (IBD) patients are at high risk for depression, and depression has been shown to affect disease course. We examined interrelations between depression, genetic risk factors for depression, and IBD flares.

METHOD

In 1973 patients (1137 Crohn's disease, 836 ulcerative colitis) of the Swiss IBD Cohort Study (SIBDCS), depressive status (hospital anxiety and depression subscale for depression, HADS-D ≥11) was assessed on a yearly basis. We investigated the impact of depression on IBD-relevant clinical outcomes in Cox proportional hazards models. We used active disease (CDAI ≥150 or MTWAI ≥10) and 2 published composite flare definitions-FNCE (physician-reported flare, nonresponse to therapy, new complication, or extraintestinal manifestation) and AFFSST (active disease, physician-reported flare, fistula, stenosis, and new systemic therapy)-as clinical end points. Additionally, 62 preselected single nucleotide polymorphisms (SNPs) were screened for cross-sectional associations with depression, and if present, their predictive value for future depression and clinical deterioration was assessed.

RESULTS

Depression was a strong risk factor for disease-related end points, including active disease (adjusted hazard ratio [aHR], 3.55; P < 0.001), AFFSST (aHR, 1.62; P < 0.001), and FNCE (aHR, 1.35; P = 0.019). The SNP rs2522833 was significantly associated with depression at enrollment (q = 0.059). The TC allele of rs588765 was negatively associated with the presence of depression at enrollment (q = 0.050) and after enrollment (aHR, 0.67; P = 0.035) and with fewer active disease states (aHR, 0.72; P = 0.045) during follow-up.

CONCLUSION

In IBD, depressive symptoms and inflammatory activity are intimately related. Depressive symptoms were a strong predictor of clinical deterioration, and genetic markers may play a role in this relationship.

The use of serotonin reuptake inhibitors increases the risk of bleeding in patients with assist devices

Background

Bleedings are frequent and dreaded complications in heart failure patients with ventricular assist devices (VAD). Serotonin reuptake inhibitor (SRI) antidepressants are widely used to treat depression in these patients, though they are attributed an increased risk of bleeding due to their modification of hemostasis. Evidence on bleeding risk of VAD patients under SRI medication is scarce and limited. We therefore aimed to assess if SRI use is associated with an elevated bleeding risk in this particularly vulnerable population.

Methods

We analyzed the medical records of 92 VAD patients at the University Heart Center Zurich between September 2004 and April 2018 for the occurrence of bleedings and the concomitant use of an SRI. Bleeding was defined as any type of post-implantation bleeding requiring medical treatment. We performed univariate analyses and linear mixed-effects models, adjusting for baseline clinical characteristics as potential predictors to identify differences in bleeding rates in patients with vs. without SRI intake.

Results

The cohort comprised 60.9% of patients with a continuous-flow VAD and 39.1% with a pulsatile-flow VAD. A total of 77.2% of patients experienced at least one bleeding incident. Overall, 28.6% of bleedings occurred under SRI therapy. A generalized linear mixed model showed a predictive effect of SRI medication on bleeding rate, independent of VAD type (z = 2.091, p = 0.037).

Conclusions

Bleeding events in heart failure patients occur frequently after VAD implantation. Patients with SRI medication were at increased risk of bleeding. The indication and use of SRI, therefore, should be considered carefully.

Type D personality is associated with depressive symptoms and clinical activity in inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) can be exacerbated by stress and depression. Type D personality, characterised by high negative affectivity and social inhibition, represents a vulnerability towards stressors and is associated with adverse outcomes in coronary heart disease.

AIMS

To assess the prevalence of Type D personality in IBD patients and investigate potential associations with disease course.

METHODS

We tested for associations between Type D (Type D Scale-14), depressive symptoms (Hospital Anxiety and Depression Scale's depression subscore ≥11) and recurrent IBD amongst Swiss IBD cohort patients. We built regression models for cross-sectional and Cox proportional hazards models for time-to-event analyses. IBD disease course was assessed by the future occurrence of active disease (Crohn's Disease Activity Index ≥150/Modified Truelove & Witts activity index ≥10) and several IBD-relevant endpoints.

RESULTS

Amongst 2275 patients (1005 ulcerative colitis, 1270 Crohn's disease), 672 (29.5%) had Type D. Type D was a significant risk factor for future active disease (adjusted hazard ratio, aHR: 1.60, corrected P value, q = 0.007) and predicted the future presence of depressive symptoms (aHR: 3.30, P < 0.001). The combination of Type D and depressive symptoms further increased the risk for active disease (aHR: 3.98, q < 0.001). However, Type D associated depressive symptoms seemed to be the main contributor to this effect as Type D's predictive power decreased considerably in models corrected for depressive symptoms (aHR: 1.32, CI: 0.97-1.79, q = 0.292).

CONCLUSIONS

Type D personality's prevalence amongst IBD patients was comparable with its prevalence in the general population. Type D was strongly associated with depressive symptoms and showed modest independent associations with IBD prognosis.

Primary cutaneous peripheral T-cell lymphoma, not otherwise specified: results of a multicentre European Organization for Research and Treatment of Cancer (EORTC) cutaneous lymphoma taskforce study on the clinico-pathological and prognostic features

BACKGROUND

Cutaneous peripheral T-cell lymphoma, not otherwise specified (PTL NOS) is an aggressive, but poorly characterized neoplasm.

OBJECTIVES

The European Organization for Research and Treatment of Cancer cutaneous lymphoma taskforce (EORTC CLTF) investigated 33 biopsies of 30 patients with primary cutaneous PTL NOS to analyse their clinical, histological, immunophenotypic features and outcome.

METHODS

Retrospective analysis of clinical data and histopathological features by an expert panel.

RESULTS

Cutaneous PTL NOS manifested clinically either with solitary or disseminated rapidly grown ulcerated tumours or disseminated papulo-nodular lesions. Histologically, a mostly diffuse or nodular infiltrate in the dermis and often extending into the subcutis was found. Epidermotropism was rarely present and only mild and focal. Unusual phenotypes were frequent, e.g. CD3⁺ /CD4^- /CD8^- and CD3⁺ /CD4⁺ /CD8⁺ . Moreover, 18% of the cases exhibited an aberrant expression of the B-cell marker CD20 by the tumour cells. All solitary tumours were located on the limbs and presented a high expression of GATA-3 but this did not correlate with outcome and therefore could not serve as a prognostic factor. The prognosis was shown to be generally poor with 10 of 30 patients (33%) dying of lymphoma within the follow-up of 36 months (mean value; range 3-144). The survival rates were 61% after 3 years (CI, 43-85%) and 54% after 5 years (CI, 36-81%). Small to medium-sized morphology of tumour cells was associated with a better outcome than medium to large or large tumour cells. Age, gender, clinical stage, CD4/CD8 phenotype and GATA-3 expression were not associated with prognosis. Chemotherapy was the most common treatment modality, but surgical excision and/or radiotherapy may represent an appropriate first-line treatment for solitary lesions.

CONCLUSIONS

Cutaneous PTL NOS shows an aggressive course in most patients independent of initial presentation, age and phenotype. Cytomorphology was identified as a prognostic factor. The data indicate a need for more effective treatment modalities in PTL NOS.

Are you angry at me? Negative interpretations of neutral facial expressions are linked to child maltreatment but not to posttraumatic stress disorder

Background: Individuals with a high prevalence of child maltreatment, e.g. those with borderline personality disorder, tend to see neutral facial expressions as negative. Objective: Our aim was to assess whether this bias is present in individuals with posttraumatic stress disorder (PTSD) and whether it is linked to child maltreatment. Methods: Thirty-nine PTSD participants, 44 traumatized and 35 non-traumatized healthy controls watched 300 one-second movies showing 30 neutral and 270 emotional facial expressions, and indicated whether they interpreted each as a neutral or as one of nine emotional expressions. Results: PTSD individuals did not perform differently than the two control groups in the recognition and interpretation of neutral facial expressions (p's < .300). Higher levels of childhood sexual and emotional abuse, and physical neglect were linked to more interpretations of neutral facial expressions as contempt (p's < .043), and (for sexual abuse and physical neglect) to more interpretations of neutral facial expressions as anger (p's < .014). Comparisons of statistical model fits suggested that childhood sexual abuse was the most relevant predictor of recognition accuracy in our sample. Alexithymia, state dissociation, interpersonal trauma, and number of experienced trauma types were not associated with deficits in the interpretation of neutral expressions. Conclusions: Child maltreatment, especially sexual abuse, may shape the interpretation of neutral facial expressions. Future research should explore whether the observed biases extend to real-life situations. If so, therapists might improve the therapeutic relationship with patients with a history of child maltreatment by paying more attention to their own non-verbal communication and their patients' responses to it. Furthermore, similarly to individuals with high depressive and high social anxiety symptoms, facial expression recognition training might counteract negativity bias in individuals with a history of childhood (sexual and emotional) abuse, and (physical) neglect.

Among Early Appearing Non-Motor Signs of Parkinson's Disease, Alteration of Olfaction but Not Electroencephalographic Spectrum Correlates with Motor Function

Olfactory decline is a frequent and early non-motor symptom in Parkinson’s disease (PD), which is increasingly used for diagnostic purposes. Another early appearing sign of PD consists in electroencephalographic (EEG) alterations. The combination of olfactory and EEG assessment may improve the identification of patients with early stages of PD. We hypothesized that olfactory capacity would be correlated with EEG alterations and motor and cognitive impairment in PD patients. To the best of our knowledge, the mutual influence of both markers of PD—olfactory decrease and EEG changes—was not studied before. We assessed the function of odor identification using olfactory “Screening 12 Test” (“Sniffin’ Sticks^®”), between two samples: patients with PD and healthy controls (HC). We analyzed correlations between the olfactory function and demographical parameters, Unified Parkinson’s Disease Rating Scale (UPDRS-III), cognitive task performance, and spectral alpha/theta ratio (α/θ). In addition, we used receiver operating characteristic-curve analysis to check the classification capacity (PD vs HC) of olfactory function, α/θ, and a combined marker (olfaction and α/θ). Olfactory capacity was significantly decreased in PD patients, and correlated with age, disease duration, UPDRS-III, and with items of UPDRS-III related to gait and axial rigidity. In HC, olfaction correlated with age only. No correlation with α/θ was identified in both samples. Combined marker showed the largest area under the curve. In addition to EEG, the assessment of olfactory function may be a useful tool in the early characterization and follow-up of PD.

Genetic Analysis of Association Between Calcium Signaling and Hippocampal Activation, Memory Performance in the Young and Old, and Risk for Sporadic Alzheimer Disease

IMPORTANCE

Human episodic memory performance is linked to the function of specific brain regions, including the hippocampus; declines as a result of increasing age; and is markedly disturbed in Alzheimer disease (AD), an age-associated neurodegenerative disorder that primarily affects the hippocampus. Exploring the molecular underpinnings of human episodic memory is key to the understanding of hippocampus-dependent cognitive physiology and pathophysiology.

OBJECTIVE

To determine whether biologically defined groups of genes are enriched in episodic memory performance across age, memory encoding-related brain activity, and AD.

DESIGN, SETTING, AND PARTICIPANTS

In this multicenter collaborative study, which began in August 2008 and is ongoing, gene set enrichment analysis was done by using primary and meta-analysis data from 57 968 participants. The Swiss cohorts consisted of 3043 healthy young adults assessed for episodic memory performance. In a subgroup (n = 1119) of one of these cohorts, functional magnetic resonance imaging was used to identify gene set-dependent differences in brain activity related to episodic memory. The German Study on Aging, Cognition, and Dementia in Primary Care Patients cohort consisted of 763 elderly participants without dementia who were assessed for episodic memory performance. The International Genomics of Alzheimer's Project case-control sample consisted of 54 162 participants (17 008 patients with sporadic AD and 37 154 control participants). Analyses were conducted between January 2014 and June 2015. Gene set enrichment analysis in all samples was done using genome-wide single-nucleotide polymorphism data.

MAIN OUTCOMES AND MEASURES

Episodic memory performance in the Swiss cohort and German Study on Aging, Cognition, and Dementia in Primary Care Patients cohort was quantified by picture and verbal delayed free recall tasks. In the functional magnetic resonance imaging experiment, activation of the hippocampus during encoding of pictures served as the phenotype of interest. In the International Genomics of Alzheimer's Project sample, diagnosis of sporadic AD served as the phenotype of interest.

RESULTS

In the discovery sample, we detected significant enrichment for genes constituting the calcium signaling pathway, especially those related to the elevation of cytosolic calcium (P = 2 × 10-4). This enrichment was replicated in 2 additional samples of healthy young individuals (P = .02 and .04, respectively) and a sample of healthy elderly participants (P = .004). Hippocampal activation (P = 4 × 10-4) and the risk for sporadic AD (P = .01) were also significantly enriched for genes related to the elevation of cytosolic calcium.

CONCLUSIONS AND RELEVANCE

By detecting consistent significant enrichment in independent cohorts of young and elderly participants, this study identified that calcium signaling plays a central role in hippocampus-dependent human memory processes in cognitive health and disease, contributing to the understanding and potential treatment of hippocampus-dependent cognitive pathology.

Continuous theta burst stimulation over the left dorsolateral prefrontal cortex decreases medium load working memory performance in healthy humans

The dorsolateral prefrontal cortex (DLPFC) plays a key role in working memory. Evidence indicates that transcranial magnetic stimulation (TMS) over the DLPFC can interfere with working memory performance. Here we investigated for how long continuous theta-burst stimulation (cTBS) over the DLPFC decreases working memory performance and whether the effect of cTBS on performance depends on working memory load. Forty healthy young subjects received either cTBS over the left DLPFC or sham stimulation before performing a 2-, and 3-back working memory letter task. An additional 0-back condition served as a non-memory-related control, measuring general attention. cTBS over the left DLPFC significantly impaired 2-back working memory performance for about 15 min, whereas 3-back and 0-back performances were not significantly affected. Our results indicate that the effect of left DLPFC cTBS on working memory performance lasts for roughly 15 min and depends on working memory load.

Converging genetic and functional brain imaging evidence links neuronal excitability to working memory, psychiatric disease, and brain activity

Working memory, the capacity of actively maintaining task-relevant information during a cognitive task, is a heritable trait. Working memory deficits are characteristic for many psychiatric disorders. We performed genome-wide gene set enrichment analyses in multiple independent data sets of young and aged cognitively healthy subjects (n = 2,824) and in a large schizophrenia case-control sample (n = 32,143). The voltage-gated cation channel activity gene set, consisting of genes related to neuronal excitability, was robustly linked to performance in working memory-related tasks across ages and to schizophrenia. Functional brain imaging in 707 healthy participants linked this gene set also to working memory-related activity in the parietal cortex and the cerebellum. Gene set analyses may help to dissect the molecular underpinnings of cognitive dimensions, brain activity, and psychopathology.

Statistical epistasis and functional brain imaging support a role of voltage-gated potassium channels in human memory

Despite the current progress in high-throughput, dense genome scans, a major portion of complex traits' heritability still remains unexplained, a phenomenon commonly termed “missing heritability.” The negligence of analytical approaches accounting for gene-gene interaction effects, such as statistical epistasis, is probably central to this phenomenon. Here we performed a comprehensive two-way SNP interaction analysis of human episodic memory, which is a heritable complex trait, and focused on 120 genes known to show differential, memory-related expression patterns in rat hippocampus. Functional magnetic resonance imaging was also used to capture genotype-dependent differences in memory-related brain activity. A significant, episodic memory-related interaction between two markers located in potassium channel genes (KCNB2 and KCNH5) was observed (P_{nominal combined} = 0.000001). The epistatic interaction was robust, as it was significant in a screening (P_nominal = 0.0000012) and in a replication sample (P_nominal = 0.01). Finally, we found genotype-dependent activity differences in the parahippocampal gyrus (P_nominal = 0.001) supporting the behavioral genetics finding. Our results demonstrate the importance of analytical approaches that go beyond single marker statistics of complex traits.

Microarray-based maps of copy-number variant regions in European and sub-Saharan populations

The genetic basis of phenotypic variation can be partially explained by the presence of copy-number variations (CNVs). Currently available methods for CNV assessment include high-density single-nucleotide polymorphism (SNP) microarrays that have become an indispensable tool in genome-wide association studies (GWAS). However, insufficient concordance rates between different CNV assessment methods call for cautious interpretation of results from CNV-based genetic association studies. Here we provide a cross-population, microarray-based map of copy-number variant regions (CNVRs) to enable reliable interpretation of CNV association findings. We used the Affymetrix Genome-Wide Human SNP Array 6.0 to scan the genomes of 1167 individuals from two ethnically distinct populations (Europe, N = 717; Rwanda, N = 450). Three different CNV-finding algorithms were tested and compared for sensitivity, specificity, and feasibility. Two algorithms were subsequently used to construct CNVR maps, which were also validated by processing subsamples with additional microarray platforms (Illumina 1M-Duo BeadChip, Nimblegen 385K aCGH array) and by comparing our data with publicly available information. Both algorithms detected a total of 42669 CNVs, 74% of which clustered in 385 CNVRs of a cross-population map. These CNVRs overlap with 862 annotated genes and account for approximately 3.3% of the haploid human genome.

We created comprehensive cross-populational CNVR-maps. They represent an extendable framework that can leverage the detection of common CNVs and additionally assist in interpreting CNV-based association studies.