Dissertation submitted in partial compliance with the requirements for the Master's Degree in Technology: Chiropractic, Durban University of Technology, 2009. / The Effect of Cervical and Thoracic Spinal Manipulations on Blood Pressure in Normotensive Males. BACKGROUND A distinguishing feature of chiropractic is manipulation that is a load delivered by hand, to specific tissues (usually a short lever bony prominence) with therapeutic intent. Chiropractic spinal manipulation results in somatovisceral reflexes, which can affect the cardiovascular system and thereby reduce blood pressure. Areas of the spine known to cause such effects are the upper cervical region and the upper thoracic region. Increased blood pressure/hypertension is a global disorder. The incidence is increasing and leads to complications of cardiovasular disease and cerebral vascular accidents OBJECTIVES The objectives of the study were to determine whether spinal manipulation evokes somatovisceral reflexes and causes a reduction in blood pressure following an atlanto-axial (C0/C1), and Thoracic segments one to five manipulations (T1-T5). METHODS Forty, asymptomatic, normotensive males between the ages of 20 – 35 years of age participated in the study. All subjects underwent four consecutive days of intervention. Day one was sham laser. Day two was C0/C1 spinal manipulation. Day three was T1-T5 thoracic manipulation. Day four was a combination of C0/C1 and T1-T5 spinal manipulations. RESULTS The results of this study suggest that blood pressure decreases following a cervical or a thoracic manipulation, however a combination of the manipulations does not have a significant cumulative effect on the reduction of blood pressure. iv CONCLUSIONS Somatovisceral reflexes are evoked following a spinal manipulation, causing a reduction in blood pressure after an upper cervical or upper thoracic manipulation. Neurophysiological effects occurring as a result of spinal manipulation may inhibit or excite somatosomatic reflexes, which changes heart rate and blood pressure.

The purpose of this study was to compare the exercise blood pressure response of subjects with a history of exercise induced hypertension between the submaximal 3-3-3 exercise test and a maximal Bruce treadmill protocol. Seven male and four female subjects with a mean age of 49 ± 2 years were recruited for the study. All subjects were selected based on a previous elevation of exercise diastolic blood pressure >_ 10 mmHg during maximal exercise.The 3-3-3 test is a short, standardized treadmill test protocol that consists of one stage of treadmill walking at a 3% grade, at 3 miles per hour, for 3 minutes. Subjects completed the 3-3-3 test on one day and the Bruce protocol on a different day with 24-48 hours between tests. Test administration order was randomized and all tests were done at the same time of the morning with all blood pressures taken by the same technician with a mercury manometer.The increase in diastolic pressure from rest was significantly lower (p<0.004) during the 3-3-3 protocol compared to the peak of the Bruce protocol. There were no statistical differences between the change in diastolic pressure from rest to peak exercise when the 3-33 protocol was compared to the Bruce Stage I or when the Bruce Stage I was compared to the peak Bruce diastolic measurement. The mean change in diastolic pressure from rest to peak exercise in the3-3-3 protocol was 3.4 ± 2.6 mmHg as compared to 9.9 ± 2.0 mmHg for the Bruce Stage I, and 15.4 ± 2.4 mmHg from rest to peak exercise with the peak Bruce. There were no differences in resting or standing systolic or diastolic blood pressure values between protocols done on separate trial days. The change in systolic response from rest to peak exercise and the peak systolic pressures were significantly different (p<0.001) between the Bruce Stage I and peak Bruce and between the 3-3-3 and peak Bruce. There were no significant differences in the heart rate and rate pressure product between the third minute of the 3-3-3 protocol and the third minute of the Bruce Stage I (p<0.001).The 3-3-3 test was not able to elicit the same rise in diastolic blood pressure as the Bruce treadmill test in this population, although the Bruce Stage I was able to elicit a response that was not statistically different than the response of the peak Bruce protocol. This implies that submaximal treadmill testing may be a feasible method to screen for the presence of an exaggerated diastolic blood pressure response to exercise. / School of Physical Education

The effect of caffeine consumption on blood pressure has been widely studied. Robertson et al. (J Clin Invest 67: 1111-1117, 1981) cited findings of tolerance to humoral and hemodynamic effects from caffeine within four days when caffeine is consumed with each meal. These findings of tolerance have not been verified. The purpose of this study was to determine the effect of caffeine intake pattern on the development of tolerance to hemodynamic effects of caffeine. Fourteen volunteers were randomly assigned to two groups of seven. One group received 250 mg of caffeine in the morning only (MO), the other group received 250 mg of caffeine in the morning, afternoon, and evening (All Day-AD). Subjects underwent a seven day trial during which blood pressure (BP) and heart rate (HR) were assessed; morning beverage (250 mg of caffeine) was ingested and BP and HR assessments were obtained every 10 minutes for 50 minutes at rest, and after 10 minutes of cycling at 100 Watts. Afternoon and evening beverages were consumed which contained 250 mg caffeine each or placebo. No significant change in SBP, DBP, or HR from rest to 40 minutes post-caffeine absorption or between caffeine dosing pattern across trial days was found. A main effect was found for SBP post caffeine consumption (MO=5.4 vs. AD= 1.3). Mean values for DBP were stable across days 3-7 (M0=3.14-4.7 mmHg) but decreased from (3.86-.14 mmHg) from days 3 to 7 (AD). SBP revealed a significant interaction during exercise and across trial days. SBP and HR for the morning only group was higher than the all day caffeine consumption group across days. However DBP was lower across days for the morning only vs. the all day intake pattern. Therefore, caffeine dosing pattern does not appear to have an effect on tolerance to the hemodynamic effects of caffeine at rest or during exercise. / School of Physical Education

The purpose of this study was to determine the short-term effect of cinnamon on blood pressure in middle-aged obese adults. Subjects consumed a beverage with (experimental) and without (control) 6 g ground cassia cinnamon. Blood pressure was assessed at baseline, and then at 30, 60, 90, 120, 180 and 240 minutes. A food frequency questionnaire was administered to estimate usual dietary intake. Twenty-six adults (9 males and 17 females), aged 40-65 years, completed the study. There was no significant difference in blood pressure at any time point between the two conditions (p>0.05). Multiple regression analysis evaluated the relationship between usual intake of diet components and control baseline blood pressure. The diet components studied did not significantly predict systolic blood pressure or diastolic blood pressure at baseline. The results of this study suggest 6 g cinnamon does not exert a short-term beneficial effect on blood pressure in middle-aged obese adults. / Department of Family and Consumer Sciences

Motivation: The prevalence of obesity is the highest among African women in South Africa. Since obesity is a major cardiovascular risk factor, African women in South Africa could be regarded as a high risk group. However, investigations on obesity-related hypertension are limited in this population group. The associations of body fat distribution and hormones such as leptin and endothelin-1 with cardiovascular function have not yet been determined in these women. It has been determined that endothelin-1 is a role player in the development and/or maintenance of hypertension in various population groups, especially African Americans. Endothelin-1 has also been found to be involved in obesity-related hypertension in non-African population groups. It has been indicated that the obesity-related hormone, leptin, also plays a role in obesity-related hypertension, especially in African Americans. Leptin levels have been found to be higher in obese hypertensive African American women compared to an obese normotensive control group. Since the above-mentioned two hormones playa prominent role in obesity and hypertension in African American and non-African population groups, the lack of data on African women in South Africa serves as motivation to conduct this investigation. Aim: To investigate obesity-related hypertension in African women through the determination of associations between various anthropometric and endocrinological variables with cardiovascular, especially vascular function. Methodology: Manuscripts presented in Chapters 2, 3 and 4 made use of data from the POWIRS (Profiles of Obese Women suffering from the Insulin Resistance Syndrome) I project where African women were selected from a government institution in the North West Province. A group of 98 women were divided into lean normotensive, overweight/obese normotensive and overweight/obese hypertensive groups. Anthropometric and cardiovascular measurements were taken and the lipid profile, leptin and endothelin-1 levels determined. The analysis of covariance (ANCOVA) was used to show significant differences between groups while adjusting for age. Partial correlation coefficients were used to show associations between various variables while adjusting for age. Stepwise linear regression analysis was also used to show associations between variables. The study presented in Chapter 5 made use of both POWIRS I and II, which are studies including Africans and Caucasians, respectively. The methodology of the two studies was the same. All subjects gave informed consent in writing and the Ethics Committee of the North-West University approved the study. The reader is referred to the "Materials and Methods" section of Chapters 2-5 for a more elaborate description of the subjects, study design and analytical methods used in each article. vii Results and conclusions of the individual manuscripts > Results from Chapter 2 showed that the volume loading effect associated with obesity was present in both overweight/obese normotensive and overweight/obese hypertensive groups, however, the accommodating effect observed in the overweight/obese normotensive group was absent in the overweight/obese hypertensive group due to decreased vascular function. This was confirmed by a high pulse pressure. Decreased vascular functioning was associated with the abdominal skin fold. This suggests that abdominal subcutaneous fat may either be a marker of visceral fat, or may in itself contribute to increased cardiovascular risk in Africans. > Results from Chapter 3 showed a negative result. Plasma endothelin-1 levels were similar for the lean normotensive, overweight/obese normotensive and overweight/obese hypertensive groups. After re-dividing the groups into normotensive and hypertensive, and then into lean and overweight/obese, still no differences could be obtained. Additionally, no correlations could be obtained between endothelin-1 and cardiovascular function in any of the groups. These findings suggest that endothelin-1 is not implicated in obesity-related hypertension in African women. > In Chapter 4, leptin levels were elevated in both overweight/obese normotensive and hypertensive groups compared to the lean normotensive group. However, leptin levels did not differ between the two overweight/obese groups. Even though leptin levels were the same, leptin was directly and positively associated with systolic blood pressure and pulse pressure and negatively with arterial compliance only in the overweight/obese hypertensive group, independent of obesity, insulin resistance, hyperinsulinemia and age. > In Chapter 5 the volume loading, as well as the accommodating effect, that is, decreased total peripheral resistance and increased arterial compliance, was present in both African and Caucasian obese groups compared to their lean controls. Even though leptin levels, body mass index and age were similar for both African and Caucasian obese groups, the accommodating effect seemed to be more prominent in the obese Caucasian group, explaining a lower diastolic blood pressure compared to the obese African group. Leptin showed a favourable negative association with diastolic blood pressure and total peripheral resistance in the obese Caucasian group, but not in the obese African group. This may indicate that leptin predominantly exerts pathological influences on obese African women, as determined previously in Chapter 4. / Thesis (Ph.D. (Physiology))--North-West University, Potchefstroom Campus, 2005.

This thesis is based on a worldwide overview (meta-analysis) of prospective observational studies of blood pressure and cholesterol, involving a centralised collection of data on over one million individuals from 59 studies, which I have co- ordinated since its inception. Analytically, the aim has been to develop and to use appropriate statistical techniques to assess the age- and sex-specific associations of usual blood pressure and of usual cholesterol with cause-specific mortality. Since the data set is uniquely large, and because appropriate methods of analysis (with full account taken of the time-dependent nature of the regression dilution bias) have been developed and used, these associations have been established more reliably. An integral part of the methodological element of the thesis has been to investigate the systematic underestimation of associations between risk factor and disease that are obtained when only a single baseline measurement is used to assess levels of such risk factors (the regression dilution bias). The extent of this bias has been investigated in each study that had repeat measurements of risk factors during follow-up. One particularly novel aspect has been the emphasis on, and methods developed to account for, the regression dilution bias in several studies simultaneously and in an appropriately time-dependent way. This thesis illustrates the extent to which random error and inappropriate statistical analysis lead to misleading conclusions concerning the importance of blood pressure and blood cholesterol, particularly in premature death. Only by studying adequate numbers of deaths (136,000 deaths among 1 million adults during 13 million person- years of follow-up) and by using appropriate statistical techniques - taking proper account of (a) the regression dilution bias; (b) the full range of blood pressure and cholesterol; (c) the opposing effects of HDL.and the remaining non-HDL cholesterol; and (d) age at death - did it become possible to provide reliable results on the true relationships between blood pressure, cholesterol fractions and vascular and other causes of death. These analyses have demonstrated reliably that, as causes of IHD death in early middle age, blood pressure and blood lipids are three to five times more important than suggested by inappropriate analyses, with no clinically relevant inverse associations with cancer or other non-vascular mortality (except, surprisingly, COPD).

Context: Although the long-term goal of antihypertensive therapy is to reduce adverse clinical outcomes, the only way to evaluate the efficacy of treatment in an individual is the magnitude of blood pressure (BP) reduction. ACE inhibitors and angiotensin receptor blockers (ARBs) are two drug classes that, by different mechanisms, inhibit the renin-angiotensin- aldosterone system that regulates BP. As these drugs are widely prescribed for hypertension, it is essential to determine and compare their effects on BP, heart rate and tolerability. Objectives: 1) To determine the dose-related effect of ACE inhibitors and ARBs on BP, heart rate and withdrawals due to adverse effects (WDAE), compared with placebo in the treatment of primary hypertension (SBP ≥ 140 mm Hg and/or ≥ DPB 90 mm Hg); and 2) To compare the relative effect on BP, heart rate and WDAE of a) each ACE inhibitor with other ACE inhibitors, b) each ARB with other ARBs, and c) all ACE inhibitors with all ARBs. Methods: Two systematic reviews of published, double-blind, randomized, controlled trials (RCTs) evaluating the BP lowering efficacy of fixed dose monotherapy with an ACE inhibitor or ARB compared with placebo for a duration of 3 to 12 weeks in patients with primary hypertension were conducted. Electronic databases were searched for RCTs and similar trial inclusion criteria and methods of analysis were used in both reviews. Results: Ninety two RCTs evaluated the dose-related BP lowering efficacy of 14 ACE inhibitors in 12 954 participants with a baseline BP of 157.1/101.2 mm Hg. Forty six RCTs evaluated the dose-related BP lowering efficacy of 9 ARBs in 13 451 participants with a baseline BP of 155.6/101.0 mm Hg. The best estimate of the near maximal trough BP reduction for ACE inhibitors and ARBs was -8/-5 mm Hg and -8/-5 mm Hg, respectively. ACE inhibitors and ARBs do not affect heart rate. The evidence for short-term WDAE (tolerability) was incomplete and weak and did not demonstrate a difference between the two classes of drugs. Conclusion: ACE inhibitors and ARBs are not different individually or as drug classes in BP lowering efficacy.

Bibliography: leaves 216-239. / xiv, 246 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The aim of this thesis is to examine the relationship between vascular reactivity, contractile proteins and blood pressure development in the spontaneously hypertensive rat (SHR). In addition, the influence of angiotensin II on blood pressure and vascular structure and function is investigated. / Thesis (Ph.D.)--University of Adelaide, Dept. of Clinical and Experimental Pharmacology, 1997

Blood pressure is one of the fundamental clinical measures. For more than 100 years, clinicians and researchers have used the mercury sphygmomanometer for blood pressure measurement. Environmental concern about mercury contamination has highlighted the need to find a replacement for traditional mercury sphygmomanometers. A number of currently used non-invasive blood pressure measurement methods have been studied in this research. The most commonly used automatic pressure monitoring method nowadays is the Oscillometric method. Height-based and Slope-based criteria are the two general means used to determine the systolic and diastolic pressures. However, these two criteria have many disputed points, making them debatable as a good standard for blood pressure measurement. For this reason, the auscultatory method continues to be the gold-standard for non-invasive blood pressure measurement. Current research uses a newly developed cuff with three different lengths of piezo film sensors and a pressure sensor to collect signals from the brachial artery. The objectives of the research are to process the measured signal from the sensors and develop a blood pressure measurement algorithm that will accurately determine the blood pressure noninvasively. Signal processing and heart beat / heart rate detection software have been developed. The best algorithm has been selected from three developed algorithms for further modification and validation. The final algorithm used two feed-forward Neural Networks to classify the acquired pressure signals into various regions of the pressure signals. The final algorithm has been tested on 258 measurements from 86 subjects. The testing result showed that the algorithm achieved grade A for both systolic and diastolic pressures according to the British Hypertension Society protocol. The mean differences (SD) between the observers and the developed algorithm were 1.44 (5.27) mmHg and 1.77 (6.17) mmHg for systolic and diastolic pressures, respectively, which also fulfilled the Association for the Advancement of Medical Instrumentation protocol. In conclusion, this algorithm was successfully developed and it is recommended for further clinical trial in a wider adult population. Further development of this algorithm also includes extending to other subgroups such as pregnant women, arrhythmia, diabetics and other subjects with diseases.

Thesis (Ph. D.)--Georgia State University, 2007. / Title from file title page. Chun Jiang, committee chair; Teryl Frey, Deborah Baro, Delon Barfuss, committee members. Electronic text (168 p. : ill. (some col.)) : digital, PDF file. Description based on contents viewed Jan. 30, 2008. Includes bibliographical references (p. 146-151).