<p>Decentering can be defined as one’s ability to detach from emotional thoughts and adopt a non-judgmental view. Prior studies on 8-week mindfulness-based stress reduction (MBSR) courses have demonstrated that as the ability to decenter increases, anxiety levels decrease. Our recent work has demonstrated that a higher ability to decenter is associated with lower arterial stiffness, however, it is unknown how decentering affects blood pressure patterns. The purpose of this study was to observe if decentering has an effect on nocturnal blood pressure dipping. Twenty- eight adults (age 25±1 years; BMI 26±1 kg/m2) volunteered for this study. All participants had a BMI <30 kg/m2, and reported no history of diabetes, smoking, or taking cardiovascular medication. Participants completed an 11-item decentering questionnaire that quantified their ability to disconnect from their emotions, then were asked to wear an ambulatory blood pressure monitor (ABPM) and actigraphy watch for 24-hours. Brachial blood pressures were measured by the ABPM every 20 minutes while awake and every 30 minutes while asleep. Systolic arterial pressure (SAP) and diastolic arterial pressure (DAP) dipping percentages were calculated by Spacelabs software from the mean values of both daytime and nighttime arterial blood pressure recordings, after adjusting sleep and wake times based on actigraphy data. Questionnaire data was analyzed using Exploratory Factor Analysis (EFA) and a reliability analysis. This revealed a three-factor structure that explained 71.53% of the variance, consisting of meta-awareness, disidentification, and nonreactivity. Nine items remained in the final questionnaire, after deleting two items which cross-loaded. Multiple linear regression analyses indicate disidentifcation as a significant predictor of SAP dipping (𝛽𝛽 = 3.333, p = 0.032) and DAP dipping (𝛽𝛽 = 3.898, p = 0.049). Preliminary results suggest that greater disidentifcation, as a component of decentering, may be associated with lower cardiovascular risk (greater SAP and DAP dipping). These findings provide promising insight into the benefits of MBSR and decentering on ambulatory blood pressure patterns, with the potential benefits of lowering overall risk for cardiovascular disease (CVD).</p>

Modern Automatic Blood Pressure Measurement Techniques are based on measuring the cuff pressure and on sensing the pulsatile amplitude variations. These measurements are very sensitive to motion of the patient or the surroundings where the patient is. The slightest unexpected movements could offset the readings of the automatic Blood Pressure meter by a large amount or render the readings totally meaningless. Every effort must be taken to avoid subjecting the body of the patient or the patient's surroundings to motion for obtaining a reliable reading. But there are situations in which we need Blood Pressure Measurements with the patient or his surroundings in motion; for instance in an ambulance while a patient is being transported to a hospital. In this thesis, we present a technique to reduce the effect of motion artifact from Blood Pressure measurements. We digitize the blood pressure waveform and use Digital Signal Processing Techniques to process the corrupted waveform. We use the differences in frequency spectra of the Blood Pressure signal and motion artifact noise to remove the motion artifact noise. The motion artifact noise spectrum is not very well defined, since it may consist of many different frequency components depending on the kind of motion. The Blood Pressure signal is more or less a periodic signal. That translates to periodicity in the frequency domain. Hence, we designed a digital filter that could take advantage of the periodic nature of the Blood Pressure Signal waveform. The filter is shaped like a comb with periodic peaks around the signal frequency components. Further processing of the filtered signal: baseline restoration and level shifting help us to further reduce the noise corruption.

Hypertension is a chronic disease with an estimated prevalence of nearly 50% in US adults. In addition to sociodemographic and lifestyle factors, evidence suggests that in utero and early life exposures may contribute to life-long risk of hypertension. This study aimed to investigate the potential associations between an individual’s birthweight and preterm birth status with their risk for hypertension in the Women’s Health Initiative (WHI) cohort. WHI is a large, multi-racial cohort of postmenopausal women. At study entry, birthweight and preterm birth status were self-reported by category (< 6 lbs., 6-7 lbs. 15 oz., 8-9 lbs. 15 oz., or ≥ 10 lbs.; ≥ 4 weeks premature or full term). Baseline and incident hypertension status were self-reported; mean systolic blood pressure, diastolic blood pressure, and 30-second pulse were also recorded at baseline by trained study staff. Linear, logistic, and Cox-proportional hazards regression models were used to generate crude and adjusted beta estimates, odds ratios, and hazards ratios, respectively. After adjusting for demographic and lifestyle factors, we found that participants born at a low birthweight had a higher mean systolic blood pressure than participants born at a normal birthweight and were at increased risk for both baseline and incident hypertension. Women born at a higher birthweight had a lower mean systolic blood pressure and were at lower risk for baseline and incident hypertension. When compared to participants born full term, participants born preterm were at increased risk for baseline and incident hypertension. These results support current research on early life exposures and health risks later in life. Long term follow-up or targeted counseling may be required for individuals born prematurely or at low birthweights to prevent and treat hypertension and associated cardiovascular outcomes.

Aim: Fatigue during team sports requiring multiple sprints can result from the combined effects of metabolic, mechanical, neurological, and immune factors. The purpose of this study was to investigate the influence of capsaicin on performance of and the physiological response to an exercise test simulating the fitness demands of team sport game conditions. Methods: This study was a placebo-controlled, crossover design. Nineteen healthy male experienced athletes age 18-30 yr consumed either 3 g/d cayenne (25.8 mg/d capsaicin) or placebo for 1 wk. Directly following the supplementation period, they completed a repeated sprint test consisting of 15 30 m maximal effort sprints on 35 s intervals. Sprint times were recorded via electronic dual-beam timing system. Fasted blood draws for interleukin-6 (IL-6) were taken at baseline prior to supplementation, 45-min pretest, and immediately post test. Heart rate (HR), blood pressure (BP), rate of perceived exertion (RPE), muscle soreness (MS), and gastrointestinal distress (GD) were measured 1-min pretest, during, posttest, and 1-min posttest. MS was also measured for 3 d posttest. Results: Relative to the placebo, capsaicin significantly reduced maximum HR by 9.3%, total average HR by 8.5%, and sprinting average HR by 6.0% (P<0.05). Capsaicin caused GD of at least 2/5 in 24.5% of subjects. There was no difference between treatments in fastest or mean sprint time, fatigue, percent change or difference in IL-6, BP, RPE, sprint or posttest MS. Conclusion: Capsaicin did not influence repeated sprint performance or the inflammatory response, but reduced HR during intense activity and causes substantial GD. / Master of Science

Objectives This systematic review aims to evaluate the evidence of non-pharmacological strategies to improve blood pressure (BP) control in patients with hypertension from African countries. Design We performed a systematic review and searched Medline, Central, CINAHL and study registers until June 2020 for randomised studies on interventions to decrease BP of patients with hypertension in African countries. We assessed the study quality using the Cochrane risk of bias tool and narratively synthesised studies on non-pharmacological hypertension interventions. Setting We included studies conducted in African countries. Participants Adult African patients with a hypertension diagnosis. Interventions Studies on non-pharmacological interventions aiming to improve BP control and treatment adherence. Outcomes Main outcomes were BP and treatment adherence. Results We identified 5564 references, included 23 with altogether 18 153 participants from six African countries. The studies investigated educational strategies to improve adherence (11 studies) and treatment by healthcare professionals (5 studies), individualised treatment strategies (2 studies), strategies on lifestyle including physical activity (4 studies) and modified nutrition (1 study). Nearly all studies on educational strategies stated improved adherence, but only three studies showed a clinically relevant improvement of BP control. All studies on individualised strategies and lifestyle changes resulted in clinically relevant effects on BP. Due to the type of interventions studied, risk of bias in domain blinding of staff/participants was frequent (83%). Though incomplete outcome data in 61% of the studies are critical, the general study quality was reasonable. Conclusions The identified studies offer diverse low-cost interventions including educative and task-shifting strategies, individualised treatment and lifestyle modifications to improve BP control. Especially trialled physical activity interventions show clinically relevant BP changes. All strategies were trialled in African countries and may be used for recommendations in evidence-based guidelines on hypertension in African settings.

The thesis investigated nicotine levels and their effects on hypertensive subjects and whether aspirin could be used in the treatment of hypertension to bring about not only an anti thrombotic effect but reduce the systemic blood pressure especially in those individuals who smoke cigarettes. The study, which also audits the use of aspirin, was conducted in Kuwait and so provides an insight of hypertensive patients very rarely considered in the literature The thesis begins in Chapter One with an extensive literature review which analyses the properties and problems that nicotine causes and its ability to cause hypertensive changes along with its multitude of other events. The physiological and pathological problems caused by nicotine are reviewed on the basis of its chemistry and pharmacological properties using a worldwide perspective rather than just focus on Kuwait. The second Chapter uses extensive analysis of the literature to determine the pharmacological properties of aspirin and its use in cardiovascular disease. The pharmacokinetics and therapeutic effects are presented with emphasis to its inhibitory effects on platelet activation which is central to the development of serious cardiovascular consequences such as stroke and myocardial infarction. The third Chapter returns to consider the literature in detail and why nicotine has specific effects on the cardiovascular system in terms of receptor stimulation and how aspirin may be able to reduce nicotine¿s cardiovascular effects and concludes with the Aims and Objectives of the thesis. The fourth Chapter investigates urinary nicotine levels in smokers from cigarettes available in Kuwait to indicate the actual levels which could be achieved by smokers in this study. This established that the levels would cause pharmacological effects demonstrating also the effects of passive smoking. The number of cigarettes smoked per day has an unpredictable effect on metabolism and urinary output of nicotine. The fifth Chapter is the major investigational section of the thesis and considers if aspirin ability to reduce cardiovascular effects, may be useful in terms of diastolic blood pressure and lipid levels in the 4 blood. The effects were suggestive that aspirin did reduce the blood pressure in hypertensive subjects but was not universal and was limited to those suffering from mild - moderate hypertension. It was determined that aspirin should be sued at the earliest age possible in these patients. The sixth Chapter involved a large scale trial of the effectiveness of aspirin treatment in hypertensive patients over a one year period in Kuwait. This used ambulatory blood pressure measurements to determine the effectiveness of daytime and nightime changes in blood pressure in patients with and without aspirin treatment. The overall conclusion was a reduced relative risk of suffering cardiovascular events in mild to moderate hypertension when aspirin (75mg/day) was administered. Specifically in smokers, aspirin lowers the systolic daytime BP and diastolic nightime BP. To support this work a comprehensive audit is provided of the use of the current use of aspirin in Kuwait hospitals / Cultural Office in the Kuwait Embassy in London; Civil Service Commission of Kuwait; The Assistant Under Secretary for the Drugs and Medical Supplied Affairs

Cluster randomized controlled trials are increasingly used to assess the effectiveness of life-style interventions in improvement of health services or prevention of disease. However, statistical methods in the analysis of cluster randomized controlled trials are not well established especially for analyzing binary outcomes. This project is motivated by the Community Hypertension Assessment Trial (CHAT) to assess the effectiveness of a 12-month community-based blood pressure management program in improving the management and monitoring of high blood pressure (BP) among older people. The study is a paired cluster randomized controlled trial, where the family physicians' practices are the clusters randomly allocated to CHAT intervention or usual practice, and a random sample of 55 patients 65 years and older were selected from the 14 practices in each study arm for health record review. The primary outcome was controlled BP over 12 months defined as systolic BP c:; 140 and diastolic BP c:; 90 for patients without diabetes or target organ damage or systolic BP c:; 130 and diastolic BP c:; 80 for patients with diabetes or target organ damage. Secondary outcomes include frequency of BP monitoring and average BP over a 12 month period. The clinical objective of this project is to evaluate the effectiveness of the CHAT intervention. The statistical objective is to compare Bayesian and classical methods of analyzing cluster-randomized trials using CHAT study as an example. We compared the results of different cluster-level analysis methods: i) un-weighted regression, ii) weighted regression, iii) random-effects meta-analytic approach, and different individual-level analyses: i) standard logistic regression, ii) robust standard errors approach, iii) generalized estimating equations, iv) random-effect logistic regression, v) Bayesian random-effect regression. We find that there is no sufficient evidence in support of the effectiveness of the CHAT intervention on all outcomes. For BP control, odds ratio (95% confidence interval) is 1.14 (0.72, 1.80) from generalized estimating equations. This result remains robust under different methods. We also find that the results from different statistical methods are different. The results from cluster-level analysis methods are quite different, while the results from the individual-level analysis methods are similar. We conclude that using various methods to analyze the trial provide good sensitivity analyses to help in interpreting the results of cluster randomized trials. Extensive simulation studies comparing the statistical powers of the different methods in different situations are required. / Thesis / Master of Science (MS)

This thesis investigates the effect of acute isometric handgrip exercise on cognitive function in young healthy adults / Acute whole-body exercise transiently improves cognitive function which may be mediated by increased cerebral blood flow (CBF) and arousal. Interestingly, small muscle mass exercise, like isometric handgrip exercise (IHG) may stimulate the same physiological responses as whole body-exercise and improve cognitive function. However, these effects are poorly understood, and whether sex-based differences exist in the cognitive response to IHG is unknown. Therefore, the purpose of this study was to investigate whether acute IHG improves cognitive function in young healthy adults and examine potential sex differences in the cognitive response to IHG. We hypothesized that acute IHG would improve cognitive function compared to a control condition, and that females would have greater improvements in cognitive function due to a lower exercise pressor response. To test this, 30 participants (n=15 females, mean age=23.8±3.3 years;BMI=25.3±4.1 kg/m2) completed either IHG or a control condition in a randomized-crossover design separated by at least 2 days. IHG consisted of four sets of 2-min unilateral squeezing a handgrip dynamometer at 30% maximal voluntary contraction separated by 3-min of rest. The control condition watched a nature documentary for 20-min. Hemodynamics (systolic blood pressure, diastolic blood pressure, mean arterial pressure, and heart rate) were assessed throughout. Executive function, working memory, and processing speed were assessed via the 4-Choice, Corsi Block, and N-Back tests. Arousal was assessed using the Felt Arousal Scale (FAS). Middle cerebral artery blood velocity (MCAv) was assessed using transcranial Doppler ultrasound. Compared to the control condition, IHG significantly increased MAP (∆ 26 ± 17 mmHg; P<0.001), HR(∆ 18 ±13 bpm; P<0.001), MCAv (∆ 5.27 ± 19.4 cm/s; P<0.001), cerebrovascular resistance (∆ 0.71 ±0.69 mmHg/cm/s; P=0.003), and arousal (∆ 2 ± 2 FAS score; P<0.001). Cerebrovascular resistance was calculated as MAP/MCAv. Overall, despite increases in MCAv and arousal, there was no effect of IHG on cognitive performance, and no sex differences were observed in the cognitive response to IHG. These findings stand in opposition to emerging work and suggests that increased CBF and arousal via acute IHG are an insufficient stimulus to enhance cognitive function in young adults. Furthermore, there seems to be no moderating effect of biological sex on the cognitive response to acute IHG. / Thesis / Master of Science (MSc) / It is well known that whole-body exercise, such as running, swimming, or lifting weights, improves cognitive function. Cognitive function encompasses our ability to pay attention, remember new information, and make important decisions. We sought to investigate whether isometric handgrip exercise (IHG) could improve cognitive function in young adults, because it may be a new and accessible way to improve cognitive abilities. We also wanted to know if IHG had a different effect on cognitive function in females compared to males. To test cognitivefunction, participants played computer games that measured how their cognitive abilities were affected by IHG. In particular, we examined how IHG impacted a participant’s memory, decision making, and speed to completion. Our results show that IHG increased blood flow to the brain and made participants feel more alert compared to a control condition, however, IHG did not improve performance on the computer games. Males and females also did not differ in terms of their performance on the cognitive tests. Overall, a single session of IHG did not improve cognitive function in young adults. Although IHG did not improve cognitive function in young adults, it should be investigated in other individuals, such as older adults and people with hypertension, who may stand to gain more from IHG.

Background: A major problem in the treatment of human hypertension is the late diagnosis of hypertension and, hence, the delayed start of treatment. Very often, hypertension has existed for a long time and cardiac damage has already developed. Therefore, we tested whether late- onset antihypertensive treatment is effective in lowering blood pressure (BP) and in reducing or even preventing left ventricular hypertrophy and fibrosis. Methods: Twenty-one male 60-week-old spontaneously hypertensive rats (SHR) were included. Fourteen rats received oral treatment with captopril (CAP) either as monotherapy or combined with nifedipine (CAP + NIF) over 22 weeks. Seven untreated SHR served as controls. We examined the therapeutic effects on BP, heart weight and histological and biochemical markers of left ventricular remodeling and fibrosis. Results: At 82 weeks of age, BP was reduced in the CAP and CAP + NIF groups by 44 and 51 mmHg, respectively (p < 0.001), but not in untreated controls. Despite the late therapy start, cardiac hypertrophy and fibrosis were attenuated compared to controls. Both treatments reduced heart weight by 1.2 mg/g (25%, p = 0.001) and collagens I and III by 66% and 60%, respectively (p < 0.001), thus proving nearly equivalent cardioprotective efficacy. Conclusion: These data clearly emphasize the benefit of antihypertensive treatment in reducing BP and mitigating the development of cardiac amage even when treatment is started late in life.

PURPOSE: Hypertension (HTN) affects one in every three adults in the United States. Often associated with the older population, this silent killer has emerged in an unsuspecting group, young military soldiers. With the rapid succession of multiple deployments, long intervals between blood pressure (BP) assessments, and the absence of cardiovascular (CV) measures during the pre and post deployment health screenings; soldiers may be at higher risk for HTN than their civilian counterparts of the same age. The purpose of this study was to explore real-time continuous CV measures of soldiers before, during, and after exposure to a simulated combat stressor as well as to assess which personal characteristics played a significant role. METHODS: Applying the Allostasis/Allostatic Load theoretical framework, a repeated measure quasi-experimental design was used to compare the CV measures of two groups: one exposed to a physical combat stressor (experimental) and the other exposed to a psychological combat stressor (control). A convenience sample of 60 college Army Reserve Officer Training Corps cadets were fitted with Tiba Medical Ambulo 2400 ambulatory BP monitors for 48 continuous hours. Several CV indices were analyzed using one-way Analysis of Variance (ANOVA), paired t-test, and independent sample t-test. Four instruments (Participant Information Sheet, State-Trait Anxiety Inventory, Paintball Perceived Stress Questionnaire, and Army Physical Fitness Test) were used to assess which characteristics played the most significant role in the CV response. RESULTS: Demographic characteristics between the two 30-cadet groups were not statistically different, with the exception of deployment history (experimental = 4, control= 0). Hours after the stress exposure, subjects in the experimental group had a higher mean awake systolic blood pressure (SBP) when compared to the control group (113.76 mm Hg vs 102.98 mm Hg, p= 009). When assessing pre and post stressor morning BP surge and evening BP decline, the control group showed the biggest change. Significant bivariate correlations (p > .05) found that: Females consistently had higher pulse rates (PR) throughout each of the phases. Age positively correlated with elevated BP during the stressor, and increased morning BP surge post stressor. African Americans had higher sleep BPs pre stressor, and decreased SBP recovery post stressor; Hispanics had higher PRs during and after the stressor. Waist circumference positively correlated with elevated BP morning surge pre stressor but, body mass index (BMI) positively correlated with elevated BP morning surge post stressor as well as elevated BP during the stressor. Family history of HTN played no significant role; however, deployment history correlated with mean awake SBP post stressor. Trait anxiety scores negatively correlated with SBP recovery while state anxiety scores positively correlated with post stressor awake mean arterial pressure and evening SPB decline. Perceived stress during the stressor negatively correlated with post stressor SBP morning surge with females reporting higher anxiety and stress. Finally, Army Physical Fitness (APFT) total scores as well as APFT run scores negatively correlated with pre and post stressor sleep PRs. DISCUSSION/IMPLICATIONS: Age, female gender, African American descent, Hispanic ethnicity, waist circumference, BMI, previous deployment history, level of fitness and the psychological stress state during and after a stressor played significant roles in soldiers' CV response. SBP was the most dynamic and informative of the CV indices and a psychological stressor was comparable to a physical stressor when observing the residual effect of stress. If a combat exercise was enough of a stressor to produce residual CV effects that lasted well into following morning, the residual effect of a lengthy strenuous deployment may be alarming. This study not only provided a snapshot of the CV health of incoming young soldiers, but also provided evidence to support policy change regarding the implementation of regular CV health assessments before and after deployment.