Smärta har stor roll i dagens samhälle och vikten av att utveckla ett effektivt behandlingsprogram bör uppmärksammas. Syftet med denna studie var att undersöka distraktionens effekt på personlig målinriktning. Om målinriktningen handlar om positivt eller negativt vinklad målinriktning. Smärta framkallades genom att deltagarna ombads utföra ett så kallat cold pressor task. Deltagarna blev indelade i tre grupper, kontrollgrupp, en grupp med positivt vinklad målinriktning och en grupp med negativt vinklad målinriktning. Resultatet indikerade på en icke signifikant skillnad mellan de tre grupperna gällande grader av smärta men deltagare som oroade sig över smärtan visade på högre smärta än de som inte oroade sig i den positiva gruppen. Resultatet kan vara vägledande för framtida studier i syftet att utveckla smärthanterings program. / Physical pain is a burden to pain patients and society. Interest has risen to develop effective pain treatment. The aim of this study was to examine if the impact of distraction on pain perception depends on the motivational characteristics of the distraction task. We examined whether the impact of distraction depended on the distraction task had a promotion or a prevention goal focus. Pain was induced using a cold pressor task. Participants were divided into three groups: a control, a promotion and a prevention group. Results indicated no significant difference between the three groups in pain intensity but among high catastrophizers in the promotion group. This result provides guidelines for further studies in the purpose of conducting effective pain treatment.

För att bättre kunna förstå och hjälpa de som drabbas av långvarig smärtproblematik är detviktigt att applicera ett biopsykosocialt perspektiv. En tidigare studie föreslog att en vissskattning av smärtintensitet i ett cold pressor test (CPT) var en biomarkör för utvecklingen avlångvarig smärtproblematik. Denna studie syftade till att undersöka huruvida dennaföreslagna biomarkör, samt variansen i sammanlagd smärtintensitet under CPT, kan förklarasav uppfattad stress respektive utmattningssymtom, utöver demografiska faktorer ochsymtomkatastrofiering. Deltagarna (n = 35) genomförde ett CPT. CPT-skattningaranalyserades tillsammans med demografiska faktorer, symtomkatastrofiering, uppfattad stressoch utmattningssymtom i hierarkiska regressionsanalyser och hierarkiska binära logistiskaregressionsanalyser. Resultaten visade att högre grad av uppfattad stress predicerade lägresmärtintensitet, utöver övriga faktorer. Utmattningssymtom hade ingen signifikant effekt påsmärtintensitet. Inga undersökta faktorer kunde förklara den föreslagna biomarkören.Resultatet indikerar att det finns en suppressoreffekt där katastrofiering och uppfattad stresspåverkar varandra ömsesidigt. Detta visar på det komplexa biopsykosociala samspel sompåverkar upplevelsen av smärta. Denna komplexitet och interaktion är viktig att ha i åtankenär individer i riskzonen för att utveckla smärtproblematik ska identifieras. / In order to help and understand patients with chronic pain, it is important to apply abiopsychosocial perspective. One previous study proposed a specific rating in a cold pressortest (CPT) as a biomarker for the development of persistent pain. This study aimed to explorewhether this proposed biomarker, and the sum of pain intensity ratings during CPT, could beexplained by perceived stress and exhaustion symptoms respectively, above and beyonddemographic factors and symptom catastrophizing. The participants (n = 35) performed aCPT. CPT-ratings were analyzed, together with demographic factors, symptomcatastrophizing, perceived stress and exhaustion symptoms, using hierarchical regressionanalyses and hierarchical binary logistic regression analyses. The results showed that higherlevels of perceived stress predicted lower pain intensity, above and beyond the other variablesexamined. Exhaustion symptoms showed no significant effect on pain intensity. None of thevariables could explain the proposed biomarker. The results indicate a suppressor effectwhere symptom catastrophizing and perceived stress interact and influence each othersimultaneously. This highlights the biopsychosocial interplay which influences painexperience. This complexity and interaction is an important factor to consider in the processof identifying individuals who are at risk for developing persistent pain.

Motivation The prevalence of cardiovascular disease is on the increase in sub-Saharan Africa largely owing to lifestyle changes associated with urbanisation. Traditional diets are being replaced with diets high in saturated fat and sugar. In addition to the nutritional transition, urbanisation in developing African countries also contributes to a more sedentary lifestyle. Together these trends contribute to a higher prevalence of obesity and hypertension that are major risk factors for the development of cardiovascular disease. Adipose tissue is now widely recognised as an endocrine organ that secretes numerous inflammatory mediators as well as adipocytokines such as leptin. The primary role of leptin is to induce satiety after a meal and to suppress appetite. However, in recent years the role of leptin in the development of obesity-related cardiovascular disease has gained increasing attention and interest. Furthermore, leptin levels not only differ with regard to gender but also ethnicity. Africans have higher leptin levels than Caucasians due to higher subcutaneous fat in Africans. Furthermore, the prevalence of hypertension and stroke are also greater in the African population. Taken together, it is important to investigate mechanisms by which elevated leptin may contribute to the development of cardiovascular disease, especially in cardiovascular disease-prone Africans. Aim The general aim of this study is to increase our understanding of the role of leptin in cardiovascular disease development by investigating associations of leptin with markers of sympathetic activity, endothelial dysfunction, and cardiovascular reactivity and recovery in Africans and Caucasians. Methodology Data from the SABPA (Sympathetic activity and Ambulatory Blood Pressure in Africans) study was used and presented in the original research articles described in Chapter 2, 3 and 4. This study included 409 African and Caucasian schoolteachers working in the Potchefstroom district in the North West Province of South Africa. Groups were stratified by ethnicity, gender and ethnicity or obesity in order to demonstrate potential differences. We performed cardiovascular measurements and determined levels of leptin, renin, cortisol, plasminogen activator inhibitor-1 (PAI-1), von Willebrand factor (vWF) and urinary albumin-to-creatinine ratio (ACR). Independent t-tests were done to compare means between groups and Chi-square tests to compare proportions. Pearson’s correlations were determined to investigate associations as well as partial correlations after minimal adjustment for potential confounders. Multiple regression analyses were performed to investigate independent associations of leptin with cardiovascular and biochemical markers according to the specific focus of each research manuscript. Results and conclusions of the individual manuscripts  Leptin may contribute to obesity-related hypertension through its sympatho-activating effects. In the first research article (Chapter 2), we compared mean leptin levels and markers of autonomic activity between Africans and Caucasians. We also investigated associations between markers of autonomic activity and leptin. Africans had higher leptin, body mass index, blood pressure and heart rate compared to Caucasians. Furthermore, Africans also demonstrated reduced heart rate variability that is indicative of autonomic imbalance. Markers of autonomic activity that collectively reflected sympathetic overactivity associated with leptin in both Africans and Caucasians, independent of significant covariates and confounders including body mass index. These findings suggest that leptin may contribute to the development of hypertension by inducing autonomic dysfunction.  Leptin exerts direct vascular effects and may thereby contribute to increased cardiovascular disease risk in the obese. We therefore investigated associations between circulating markers of endothelial dysfunction (PAI-1, vWF and ACR) and leptin in lean and obese groups, irrespective of ethnicity (Chapter 3). As expected, leptin and plasminogen activator inhibitor-1 antigen levels were higher in the obese group. We found no differences for von Willebrand factor antigen and urinary albumin-to-creatinine ratio. In the obese group, all markers of endothelial dysfunction were positively associated with leptin in univariate analysis. However, after full adjustment in multiple regression analyses, only the association with plasminogen activator inhibitor-1 remained significant. Higher leptin levels in the obese may possibly induce endothelial dysfunction through mechanisms related to thrombotic vascular disease.  Greater cardiovascular reactivity to stress and prolonged recovery thereafter associates with increased cardiovascular disease risk. In the final research article (Chapter 4), we therefore investigated the relationship between cardiovascular reactivity and recovery to acute stress, induced by the cold pressor test, and leptin in Africans and Caucasians. Africans demonstrated greater cardiovascular reactivity compared to Caucasians. Associations of blood pressure, stroke volume, cardiac output, total peripheral resistance and arterial compliance reactivity with leptin were investigated during the stressor application and 1, 3 and 5 minutes post-stressor. There were no independent associations between cardiovascular reactivity and leptin during the stressor, and a few correlations at 1 and 3 minutes post-stressor. Associations were mostly evident at 5 minutes post-stressor and in Africans. We argue that higher leptin levels relate to impaired post-stress recovery and thereby could contribute to hypertension development in Africans. General conclusion Elevated leptin relates to sympathetic overactivity, vascular damage and delayed post-stress recovery, and thereby could contribute to increased cardiovascular disease risk. / PhD (Physiology), North-West University, Potchefstroom Campus, 2015

Motivation The prevalence of cardiovascular disease is on the increase in sub-Saharan Africa largely owing to lifestyle changes associated with urbanisation. Traditional diets are being replaced with diets high in saturated fat and sugar. In addition to the nutritional transition, urbanisation in developing African countries also contributes to a more sedentary lifestyle. Together these trends contribute to a higher prevalence of obesity and hypertension that are major risk factors for the development of cardiovascular disease. Adipose tissue is now widely recognised as an endocrine organ that secretes numerous inflammatory mediators as well as adipocytokines such as leptin. The primary role of leptin is to induce satiety after a meal and to suppress appetite. However, in recent years the role of leptin in the development of obesity-related cardiovascular disease has gained increasing attention and interest. Furthermore, leptin levels not only differ with regard to gender but also ethnicity. Africans have higher leptin levels than Caucasians due to higher subcutaneous fat in Africans. Furthermore, the prevalence of hypertension and stroke are also greater in the African population. Taken together, it is important to investigate mechanisms by which elevated leptin may contribute to the development of cardiovascular disease, especially in cardiovascular disease-prone Africans. Aim The general aim of this study is to increase our understanding of the role of leptin in cardiovascular disease development by investigating associations of leptin with markers of sympathetic activity, endothelial dysfunction, and cardiovascular reactivity and recovery in Africans and Caucasians. Methodology Data from the SABPA (Sympathetic activity and Ambulatory Blood Pressure in Africans) study was used and presented in the original research articles described in Chapter 2, 3 and 4. This study included 409 African and Caucasian schoolteachers working in the Potchefstroom district in the North West Province of South Africa. Groups were stratified by ethnicity, gender and ethnicity or obesity in order to demonstrate potential differences. We performed cardiovascular measurements and determined levels of leptin, renin, cortisol, plasminogen activator inhibitor-1 (PAI-1), von Willebrand factor (vWF) and urinary albumin-to-creatinine ratio (ACR). Independent t-tests were done to compare means between groups and Chi-square tests to compare proportions. Pearson’s correlations were determined to investigate associations as well as partial correlations after minimal adjustment for potential confounders. Multiple regression analyses were performed to investigate independent associations of leptin with cardiovascular and biochemical markers according to the specific focus of each research manuscript. Results and conclusions of the individual manuscripts  Leptin may contribute to obesity-related hypertension through its sympatho-activating effects. In the first research article (Chapter 2), we compared mean leptin levels and markers of autonomic activity between Africans and Caucasians. We also investigated associations between markers of autonomic activity and leptin. Africans had higher leptin, body mass index, blood pressure and heart rate compared to Caucasians. Furthermore, Africans also demonstrated reduced heart rate variability that is indicative of autonomic imbalance. Markers of autonomic activity that collectively reflected sympathetic overactivity associated with leptin in both Africans and Caucasians, independent of significant covariates and confounders including body mass index. These findings suggest that leptin may contribute to the development of hypertension by inducing autonomic dysfunction.  Leptin exerts direct vascular effects and may thereby contribute to increased cardiovascular disease risk in the obese. We therefore investigated associations between circulating markers of endothelial dysfunction (PAI-1, vWF and ACR) and leptin in lean and obese groups, irrespective of ethnicity (Chapter 3). As expected, leptin and plasminogen activator inhibitor-1 antigen levels were higher in the obese group. We found no differences for von Willebrand factor antigen and urinary albumin-to-creatinine ratio. In the obese group, all markers of endothelial dysfunction were positively associated with leptin in univariate analysis. However, after full adjustment in multiple regression analyses, only the association with plasminogen activator inhibitor-1 remained significant. Higher leptin levels in the obese may possibly induce endothelial dysfunction through mechanisms related to thrombotic vascular disease.  Greater cardiovascular reactivity to stress and prolonged recovery thereafter associates with increased cardiovascular disease risk. In the final research article (Chapter 4), we therefore investigated the relationship between cardiovascular reactivity and recovery to acute stress, induced by the cold pressor test, and leptin in Africans and Caucasians. Africans demonstrated greater cardiovascular reactivity compared to Caucasians. Associations of blood pressure, stroke volume, cardiac output, total peripheral resistance and arterial compliance reactivity with leptin were investigated during the stressor application and 1, 3 and 5 minutes post-stressor. There were no independent associations between cardiovascular reactivity and leptin during the stressor, and a few correlations at 1 and 3 minutes post-stressor. Associations were mostly evident at 5 minutes post-stressor and in Africans. We argue that higher leptin levels relate to impaired post-stress recovery and thereby could contribute to hypertension development in Africans. General conclusion Elevated leptin relates to sympathetic overactivity, vascular damage and delayed post-stress recovery, and thereby could contribute to increased cardiovascular disease risk. / PhD (Physiology), North-West University, Potchefstroom Campus, 2015

No description available.

Previous research has shown that there are several components involved in how we perceive pain, e.g. social and psychological factors such as expectations of pain. A cold pressor experiment was conducted to investigate the impact of negative/positive information on pain perception. We also investigated if a cognitive conflict created by disconfirming information of a pain expectation influences the pain experience. 106 participants (49 men and 57 women) got to hold their hand in 5°C water for 1 minute. The main outcome variable was self-reported pain during the cold pressor test. The results show that participants receiving negative information perceived more pain than the group receiving positive information. There was no significant difference in pain perception between those who were confirmed or disconfirmed in an expectation, nor was there a difference in cognitive conflict between the two groups. This is a first attempt to explore pain and cognitive conflict and can work as an inspiration for further investigation. / Tidigare forskning har visat att det är flera komponenter involverade i en smärtupplevelse, bland annat sociala och psykologiska faktorer så som förväntningar. Ett kallvattenexperiment utfördes för att undersöka positiv/negativ information och dess påverkan på upplevelsen av smärta. Vi undersökte även om smärta påverkas av en kognitiv konflikt skapad av en disconfirmation av en smärtförväntning. 106 deltagare (49 män och 57 kvinnor) fick hålla sin hand i 5°C vatten i en minut. Vårt mätinstrument var själv-rapporterad smärta vid kallvattentestet. Resultatet visade att deltagare som fick negativ information upplevde mer smärta än de som fick positiv information. Det fanns ingen signifikant skillnad mellan de som blev disconfirmed och confirmed i sin förväntan och inte heller någon skillnad mellan grupperna i upplevd kognitiv konflikt. Detta första försök att undersöka smärta och kognitiv konflikt kan bli till en inspiration för vidare undersökningar.

Tobacco smoking has been associated with the development, protraction, and exacerbation of chronically painful conditions. Conversely, there is reason to believe that smokers may be motivated to use tobacco as a means of coping with their pain. To date, no controlled, experimental studies have tested for a causal relationship between pain and smoking motivation. The primary aim of the current study was to test the hypothesis that laboratory-induced cold-pressor pain would enhance smoking motivation, as measured by self-reported urge to smoke and observation of immediate smoking behavior. The effect of a smoking cue was also tested. Smokers (n = 132) were randomly assigned to one of four conditions in this 2 (Pain Manipulation) X 2 (Smoking Cue Manipulation) crossed factorial between-subjects design. Results indicated that both pain induction and the presence of smoking cues increased urge ratings, and pain induction also produced a shorter latency to smoke. The relationship between pain and increased urge to smoke was partially mediated by pain-induced negative affect. This study provides the first experimental evidence that situational pain can be a potent motivator of smoking.

The current study utilized an early-stage translational approach (Tashiro & Mortensen, 2006) to empirically test the immediate effect of a 15-minute mindfulness intervention on acute pain experience. The study employed a three-group, repeated measures experimental design with two active control conditions (sham mindfulness and attention control) and an analogue pain induction procedure (cold-pressor test). The sample consisted of 165 university students. Repeated measures analyses found an interaction effect between condition and time for subjective pain intensity and an interaction effect between gender and time for pain tolerance. Trends show that attention control increased pain intensity, whereas mindfulness decreased pain intensity. Females exhibited greater pain tolerance at post-intervention across conditions. Analyses yielded no significant differences between conditions among dependent variables of pain tolerance, state affect, or state anxiety. A moderate relationship was found between fear of pain and pain tolerance at pre-intervention, but failed to significantly moderate outcome in main analyses. Post-hoc analyses revealed a subset of "high pain tolerant" participants, who endorsed significantly higher trait mindfulness, lower fear of pain, and lower pain catastrophizing compared to the remainder of participants. Negative affect was related to increased pain intensity within the attention control condition. Suggestions for future research and clinical implications of research in this area are discussed.

This study compared the relative efficacy of four imagery techniques in increasing tolerance to cold pressor pain. Relevant pleasant, relevant unpleasant, irrelevant pleasant, and irrelevant unpleasant imagery strategies were compared in a two-way factorial design. Prior research suggested that pleasantness and relevance both affect imagery potency. This study attempted to assess the relative contribution of these two variables to increases in pain tolerance. Also investigated were the roles of several hypothesized mediating variables; namely, contextual valence, self-efficacy, treatment credibility, and involvement in imagery. The subjects were 60 female undergraduates who were randomly assigned to the four imagery groups. Two-way analysis of covariance were performed on all dependent variables, using pain threshold as the covariate. Pearons r.'s were used to test correlational hypotheses.

The first part of the thesis explored the pattern of emotional reactivity amongst individuals with Borderline Personality Disorder (BPD). A previous review (Rosenthal, Gratz, Kosson, Cheavens, Lejuez & Lynch, 2008) claimed that a discrepancy exists in the subjective versus objective patterns of responding to emotional stimuli in those with BPD. The present review assessed the reliability of such findings by reviewing a more homogenous sample of studies that had used similar methodological procedures, in addition to a range of subjective and objective measures. It also aimed to investigate psychophysiological factors associated with this proposed divergent pattern of responding. The methodological quality of all included studies was assessed. The evidence reviewed disputes claims that BPD individuals display diminished physiological reactivity, despite equal or higher self-reported emotional reactivity than controls. Instead, the present review found that individuals with BPD react more severely (both psychologically and physiologically) to experimental stimuli, than controls, particularly when the stimuli is personally-relevant. Disruption of specific brain structures involved in the regulation of emotion within the Autonomic Nervous System (ANS) are implicated in this heightened profile of emotional reactivity. Furthermore, present state dissociation acts as a defence mechanism which appears to limit cognitive processing abilities such as problem-solving, attention and concentration in those with BPD. The second part of the thesis described a randomised controlled study investigating the effects of an attention training technique on pain tolerance. The Attention Training Technique (ATT; Wells, 1990) is a brief technique used in metacognitive therapy to modify attentional control. The effect of ATT versus Progressive Muscular Relaxation (PMR) on pain tolerance was examined in a sample of individuals who had experienced early childhood trauma (N=57). Participants were randomly assigned to either the ATT condition (N = 29) or the PMR condition (N = 28). A laboratory stressor was included: The Cold Pressor Task (CPT) as an objective measure of pain tolerance. Results supported the hypothesis that ATT modified performance on the CPT. Individuals assigned to the ATT condition were able to persist significantly longer with the CPT than those in the PMR condition. Theoretical and clinical implications of the findings are discussed. Results provide preliminary evidence for the possible benefits of ATT within medical settings. The third part of the thesis critically reflected on the methodological issues and dilemmas presented by the systematic review process, as well as the methodological and ethical issues raised by the research study.