Erland Svensson

Mood Effects of Diazepam and Caffeine

Changes in mood after administration of Diazepam and Caffeine were analyzed. Six aspects were studied: pleasantness, activation, extraversion, calmness, social orientation and control. In addition to this check list, mood ratings using magnitude estimation of selected adjectives were obtained. It was found that Diazepam decreased feelings of activation and extraversion and increased calmness. Caffeine had no clear effects on the check list, but on the magnitude estimation scale some effects opposite to those of Diazepam were observed. Men reported a higher degree of pleasantness than women after administration of Diazepam. No differences in heart rate were found. Few distinct scale values were utilized on the magnitude estimation scale and the discriminative power was found to be larger for the check list than for the magnitude estimation scale.

Mood Effects of Alcohol

Doses of 0.41, 0.63, and 0.85 g alcohol/kg body weight were administered using a double-blind Latin square design to subjects who made mood ratings at seven points in time during 3 h subsequent to administration. The subjects felt more euphoric and extraverted and less tense at mainly the highest dose levels. Lower dose levels tended to induce more negative feelings. Frequent consumers of alcohol derived greater affective benefit than rare drinkers. Intercorrelations between ratings of subjective intoxication and mood variables indicated that the meaning of the variable ‘subjective intoxication’ was different for the three dose levels and for different points in time.

Psychological and Psychophysiological Models of Pilot Performance for Systems Development and Mission Evaluation

The purpose of our study was to analyze the effects of mission complexity on pilot mental workload, situational awareness, and pilot performance and to develop models by means of structural equation modeling. Earlier studies indicate that mission complexity affects mental workload and that mental workload affects situational awareness, which, in turn, affects pilot performance. In the first phase of this study, 20 fighter pilots performed 150 missions. In the second phase, 15 pilots performed 40 simulated missions. The pilots answered questionnaires on mission complexity, mental workload, mental capacity, situational awareness, and performance. During the simulated missions we measured eye fixation rate, heart rate, and blink rate. Model analyses show that mission complexity affects workload and that workload affects situational awareness and performance. Significant relationships occur between heart rate and rated workload, mental capacity, situational awareness, and performance. Model analyses show a workload factor combining psychological and physiological aspects and a performance factor combining situational awareness and pilot performance. Significant relationships occur among heart rate, eye fixation rate, and blink rate.

Depressive symptoms and inflammation in patients hospitalized for heart failure

BACKGROUND Depressive symptoms in patients with heart failure (HF) are common and might be associated with inflammation. No studies have examined both the cross-sectional and prospective association between inflammation and depressive symptoms in patients with HF with adequate correction for disease severity. The aim of this study was to describe if the cytokines interleukin-6 (IL-6) and C-reactive protein (CRP) are associated with depressive symptoms in hospitalized HF patients. METHODS Data from 517 patients hospitalized for HF from the COACH study were analyzed on inflammation markers (IL-6 and CRP) and depressive symptoms (Center for Epidemiological Studies Depression-Scale). RESULTS Heart failure patients with depressive symptoms (n = 208, 40%) had significantly higher plasma values of IL-6 (median 12.8 pg/mL vs median 11.0 pg/mL, P = .018) and CRP (median 2.4 mg/mL vs median 2.1 mg/mL, P = .03) compared with the nondepressed patients. Structural equation modelling showed that the factor inflammation (including IL-6 and CRP) was associated with depressive symptoms (β = 0.18, P < .05) when left ventricular ejection fraction and plasma values brain natriuretic peptides were included in the model. A small negative (β = -0.18, P < .05) effect was found between inflammation at baseline and the change in depressive symptoms during the 18 months of follow-up. CONCLUSIONS Higher levels of inflammatory markers are independently associated with depressive symptoms in HF patients, even after correcting for disease severity. There is no clear relationship between inflammation at baseline and depressive symptoms during the 18 months of follow-up.

The contribution of heart failure to sleep disturbances and depressive symptoms in older adults

Background: The aim of this study was to explore the associations between physical symptoms, sleep disturbances, and depressive symptoms in community-dwelling elderly individuals, comparing persons with and without heart failure (HF). Methods: A total of 613 older adults (mean age 78 years) underwent clinical and echocardiographic examinations. Questionnaires were used to evaluate sleep disturbances and depressive symptoms. A model was developed in those with HF (n = 107) and compared with those without HF (n = 506). Results: Cardiopulmonary symptoms (ie, dyspnea and nighttime palpitations) and pain had significant direct associations with sleep disturbances, which indirectly affected depressive symptoms. The model was essentially the same in those with and without HF except that the effect of sleep disturbances on depressive symptoms was stronger in those with HF (β = 0.64 vs β = 0.45, P = .006). Conclusion: In community-dwelling older adults, regardless of their diagnosis, physical symptoms had a direct effect on sleep disturbances and an indirect effect on depressive symptoms.

Levels of sP-selectin and hs-CRP Decrease with Dietary Intervention with Selenium and Coenzyme Q10 Combined: A Secondary Analysis of a Randomized Clinical Trial

Background/Objectives Inflammation and oxidative stress are central in many disease states. The major anti-oxidative enzymes contain selenium. The selenium intake in Europe is low, and supplementation with selenium and coenzyme Q10, important anti-oxidants, was evaluated in a previous study. The aim of this study was to evaluate response on the inflammatory biomarkers C-reactive protein, and sP-selectin, and their possible impact on cardiovascular mortality. Subjects/Methods 437 elderly individuals were included in the study. Clinical examination, echocardiography, electrocardiography and blood samples were drawn. The intervention time was 48 months, and median follow-up was 5.2 years. The effects on inflammation/atherosclerosis were evaluated through analyses of CRP and sP-selectin. Evaluations of the effect of the intervention was performed using repeated measures of variance. All mortality was registered, and endpoints of mortality were assessed by Kaplan-Meier plots. Results The placebo group showed a CRP level of 4.8 ng/mL at the start, and 5.1 ng/mL at the study end. The active supplementation group showed a CRP level of 4.1 ng/mL at the start, and 2.1 ng/mL at the study end. SP-selectin exhibited a level of 56.6 mg/mL at the start in the placebo group and 72.3 mg/mL at the study end, and in the active group the corresponding figures were 55.9 mg/mL and 58.0 mg/mL. A significantly smaller increase was demonstrated through repeated measurements of the two biomarkers in those on active supplementation. Active supplementation showed an effect on the CRP and sP-selectin levels, irrespective of the biomarker levels. Reduced cardiovascular mortality was demonstrated in both those with high and low levels of CRP and sP-selectin in the active supplementation group. Conclusion CRP and sP-selectin showed significant changes reflecting effects on inflammation and atherosclerosis in those given selenium and coenzyme Q10 combined. A reduced cardiovascular mortality could be demonstrated in the active group, irrespective of biomarker level. This result should be regarded as hypothesis-generating, and it is hoped it will stimulate more research in the area.

Determinants of global perceived health in community-dwelling elderly screened for heart failure and sleep-disordered breathing.

The relationships between heart failure (HF), sleep-disordered breathing (SDB), insomnia, depressive symptoms, and excessive daytime sleepiness (EDS), as well as their relationship to Global Perceived Health (GPH) in an elderly community-dwelling population, have not been explored. Data from 331 community-dwelling elderly (71-87 years old) were collected by echocardiography, polygraphy, and specific questionnaires. Factor analyses and structural equation modeling were used to explore the relationships between HF, SDB, sleep, psychosocial factors, and GPH. Exploratory and confirmatory factor analyses derived a 5-factor model representing SDB, insomnia, systolic function, breathlessness/physical function, and psychosocial function. Structural equation modeling analyses were used to explore the relationships between the 5 factors and to GPH. Sleep-disordered breathing had a weak effect on systolic function, but no effects on any of the other factors or GPH were found. Psychosocial function and breathlessness/physical function directly affected GPH. Indirect effects on GPH, mediated by psychosocial function, were found for breathlessness/physical function and insomnia. Systolic function also had an indirect effect on GPH. The fact that SDB in the elderly has no obvious negative associations to sleep complaints or GPH does not exclude them from being adequately treated for SDB. However, the present study has shown that SDB, by means of self-rated sleep complaints and health-related quality of life, can be problematic to detect. Psychosocial function was the most important factor for perceived GPH as it had a direct effect, as well as mediated the factors breathlessness/physical function and insomnia effects, on GPH. This study indicates that interventions in clinical practice targeting psychosocial dysfunction, such as depressive symptoms, could help to improve GPH in the elderly with or without HF.

The contribution of hypoxia to the association between sleep apnoea, insomnia, and cardiovascular mortality in community-dwelling elderly with and without cardiovascular disease

Aims: This study explores if nightly hypoxia (i.e. percentage of sleep time with oxygen saturation lower than 90% (SaO2<90%)) contributed to the association between sleep-disordered breathing (SDB) and insomnia in community-dwelling elderly with and without cardiovascular disease (CVD). A second aim was to explore a potential cut-off score for hypoxia to predict insomnia and the association of the cut-off with clinical characteristics and cardiovascular mortality. Method: A total of 331 community-dwelling elderly aged 71–87 years underwent one-night polygraphic recordings. The presence of insomnia was recorded by a self-report questionnaire. The presence of CVD was objectively established and mortality data were collected after three and six years. Results: In both patients with CVD (n=119) or without CVD (n=212) SDB was associated with hypoxia (p<0.005). Only in the patients with CVD was hypoxia associated with insomnia (p<0.001) which mediated an indirect effect (p<0.05) between SDB and insomnia. Hypoxia of more than 1.5% of sleep time with SaO2<90% was found to be a critical level for causing insomnia. According to this criterion 32% (n=39) and 26% (n=55) of those with and without CVD had hypoxia, respectively. These groups did not differ with respect to age, gender, body mass index, diabetes, hypertension, respiratory disease or levels of SDB. However, in the CVD group, hypoxia was associated with cardiovascular mortality at the three-year follow-up (p=0.008) and higher levels of insomnia (p=0.002). Conclusion: In the elderly with CVD, SDB mediated by hypoxia can be associated with more insomnia and a worse prognosis.

Sickness Behavior in Community-Dwelling Elderly Associations With Impaired Cardiac Function and Inflammation

Sickness behavior is a cluster of symptoms that occur as a response to an infection and alterations in the inflammatory response. Under normal circumstances, sickness behavior is fully reversible once the pathogen has been cleared. Aging and chronic illness such as heart failure are associated with enhanced inflammatory activity that lasts for a long duration and no longer represents an adaptive response. The aim of this study was to explore whether inflammation mediates the relationship between impaired cardiac function and a symptom cluster including anhedonia, fatigue, and sleepiness, which might represent sickness behavior in community-dwelling elders. Structural equation modeling (SEM) showed that the factor impaired cardiac function (i.e., N-terminal fragment of pro-brain natriuretic peptide, left ventricular ejection fraction, and the heart failure medications angiotensin converting enzyme inhibitor, angiotensin receptor blockade, β-blocker, and diuretics) was associated with both inflammation (i.e., C-reactive protein; β = .26) and the symptom cluster (β = .31). Inflammation had a significant direct, but smaller, association with the symptom cluster (β = .21). By this pathway, inflammation also mediated an indirect association between impaired cardiac function and the symptom cluster (β = .05). Including creatinine, blood glucose, ischemic heart disease, previous and current tumor, respiratory disease, age, and body mass index in the SEM model did not change these associations. Our results imply that some aspects of the symptom panorama in elderly individuals with impaired cardiac function or heart failure could represent sickness behavior.

A Meta Study of Transfer of Training

A Meta study of four empirical studies of simulator training was performed. The empirical studies were performed at a battle tank simulator, a combat vehicle simulator, an active sonar anti-submarine warfare simulator, and at a simulated command and control staff exercise of an international naval mine countermeasures mission. The combined number of participants in the Meta study made use of inferential and causal statistics possible. The results showed higher ratings of motivation/fun and effect on reality than fidelity. This suggests that a simulator can provide both motivating and valuable training even if it does not have very high fidelity. The casual analysis with LISREL provided a model showing that the feeling of involvement in the simulation influences the training in the simulator, which in turn has a positive influence on the transfer of training to real world performance. Since the analysis is based on amalgamated data from different studies with partly different conditions, site specific models may be different.