| For medical practitioners and the general public - High Blood Pressure Journal Article Catalog. |
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| Insufficient duration of action of antihypertensive drugs mediates high blood pressure in the morning in hypertensive population: the Ohasama study Chonan, K., J. Hashimoto, et al. (2002), Clin Exp Hypertens 24(4): 261-75. Abstract: Blood pressure (BP) usually peaks in the morning. The circadian variation of the onset of cardiovascular disease mimics this circadian BP variation. To examine the determinants of the BP difference between the self-recorded BP in the morning (home BP) and daytime average ambulatory BP a cross sectional study was done in the general population of Ohasama, Japan. 1207 subjects > or = 20 years measured both home (more than 14 times) and ambulatory BPs (326 treated for hypertension and 881 untreated subjects), The prevalence of subjects with the systolic BP difference (home BP in the morning - daytime ambulatory BP) of > or = 10 mmHg (high morning BP) was 5.6% in untreated normotensives, 2.9% in untreated hypertensives, and 25.8% in treated hypertensives. This trend was also observed for diastolic pressure. Multiple regression analysis demonstrated that age, male sex, and use of antihypertensive drugs were positively associated and day-night difference of BP was negatively associated with the high morning BP, respectively. These results suggest an insufficient duration of antihypertensive action of widely used antihypertensive drugs in Japan from the 1980s to 1990s. The amplitude of the day-night difference of ambulatory BP in subjects with a high morning BP was lower (non-dipping) than that without high morning BP. The high morning BP is not necessarily accompanied by hypertension but might be mediated, at least in part, by an insufficient duration of action of antihypertensive drugs. The high morning BP accompanies so-called non-dipper pattern of circadian BP variation. An insufficient duration of action of drugs may partly mediate non-dipping in subjects with antihypertensive medication. |
| Insulin and hypertension--the mechanisms of high blood pressure during chronic insulin infusion Yokota, M., K. Shimoda, et al. (1989), Nippon Jinzo Gakkai Shi 31(8): 875-81. Abstract: The purpose of this study was to assess the effects of chronic insulin infusion on blood pressure and urinary sodium excretion in Wistar rats. Fifteen Male Wistar rats weighing about 220 g were used. The rats were housed in metabolic cage and measured urine volume. Osmotic minipumps filled with insulin (0.57 U/day, Insulin group, n = 9) or saline (0.014 cc/day, Control group, n = 6) were implanted subcutaneously under ether anaesthesia, and blood pressure, urine volume, urinary sodium excretion (UNaV), plasma renin activity (PRA), plasma norepinephrine concentration (PNE) were measured for 4 weeks. In insulin group, there were no significant changes on plasma glucose levels, but systolic blood pressure rose significantly from 119 mmHg to 140 mmHg after 4 weeks. In this group, urine volume, UNaV, and PRA were significantly lower than those of control group and PNE was tended higher but not significant (P less than 0.1). Exogenous NE was given intravenously to assess the endogenous NE activity. Blood pressure elevation caused by exogenous NE in insulin group was suppressed significantly than that of control group. On the basis of these findings, we conclude that insulin can cause high blood pressure due to sodium retention and activation of endogenous NE. |
| Insulin resistance and abnormal electrocardiograms in patients with high blood pressure Sheu, W. H., C. Y. Jeng, et al. (1992), Am J Hypertens 5(7): 444-8. Abstract: Plasma glucose and insulin responses to an oral glucose challenge and fasting plasma lipid and lipoprotein concentration were compared in 25 normal individuals and 53 patients with high blood pressure. Patients with hypertension were further subdivided into two groups--normal electrocardiogram (EKG) (n = 24) or abnormal EKG (n = 29)--using the Minnesota code criteria. Patients with hypertension and an abnormal EKG had significantly higher plasma glucose and insulin concentrations following oral glucose than did the control population. Furthermore, plasma triglyceride (TG) concentration was higher and high density lipoprotein cholesterol concentration lower then normal in hypertensive patients with an abnormal EKG, and the ratio of total to HDL cholesterol was higher in this subgroup. Values for patients with high blood pressure and a normal EKG were intermediate. Insulin-mediated glucose uptake was also measured in a subset of patients with hypertension and either a normal (n = 18) or abnormal (n = 17) EKG. When these two subgroups were compared, those with high blood pressure and an abnormal EKG were significantly more insulin resistant than patients with hypertension and a normal EKG. In addition, they also had higher plasma glucose and insulin responses to oral glucose, higher fasting plasma triglyceride and cholesterol concentrations, and an increase in the ratio of total to HDL cholesterol. Thus, patients with high blood pressure have abnormalities of glucose, insulin, and lipid metabolism when compared to a nonhypertensive control group, and the magnitude of these metabolic defects is significantly greater in patients with high blood pressure who have EKG evidence of coronary heart disease. |
| Insulin resistance, body mass index, waist circumference are independent risk factor for high blood pressure Sung, K. C. and S. H. Ryu (2004), Clin Exp Hypertens 26(6): 547-56. Abstract: OBJECTIVES: The purpose of the present study was to investigate the relationships between blood pressure (BP), insulin resistance as determined by a homeostasis model (HOMA-IR), and body fat distribution. METHODS: Anthropometric indices of adiposity, metabolic variables (fasting serum insulin and a homeostasis model assessment HOMA index of insulin sensitivity), BP and several cardiovascular risk factors were measured during a cross sectional survey of 53477 apparently healthy Korean subjects who requested a health status check. Hypertension was defined as a systolic BP > or = 140 mmHg or a diastolic BP > or = 90 mmHg and we excluded the subjects taking BP-lowering medication. RESULTS: Systolic and diastolic blood pressure (SBP, DBP) were positively and significantly associated with age, body mass index, waist circumference, and waist/hip ratio. In addition, SBP and DBP were positively associated with fasting serum insulin levels and the HOMA index. By multiple regression analysis age, waist circumference, body mass index, HOMA index and female sex were independently associated with either increased SBP or DBP. When the population is divided into quintiles according to insulin resistance (measured by HOMA analysis) prevalence of hypertension in the second, third, fourth and fifth quintiles compared to subjects in the first quintile are 1.004(95% CI 0.875-1.152, p = 0.957), 1.200(95% CI 1.052-1.369, p = 0.007), 1.312(95% CI 1.151-1.494 p < 0.001), and 1.603(95% CI 1.408-1.825 p < 0.001). In addition age, sex, body mass index and waist circumference were found to be significantly associated with hypertension. CONCLUSION: Our results showed that insulin resistance, body mass index and waist circumference are independent risk factors of a high BP in Koreans. |
| Insulin therapy could prevent salt-induced high blood pressure in diabetes mellitus Orie, N. N. and F. E. Osirim (1997), East Afr Med J 74(9): 579-81. Abstract: The effectiveness of insulin replacement therapy in the prevention of salt-induced hypertension in diabetes mellitus was examined using Alloxan diabetic rats. Early daily (eight units/day) treatment with insulin prevented the development of high blood pressure after six weeks of high-salt feeding. The mean arterial pressure (MAP) for the early insulin-treated and salt-fed group (DET-SF) was 123.37 +/- 6.37 mmHg which was close to the value for normal (control) rats 128.17 +/- 4.84 mmHg, but significantly (p < 0.001) less than that of the untreated diabetic salt-fed group (DSF) which was 164.58 +/- 8.33 mmHg. The nondiabetic salt-fed (NDSF) group had MAP of 150.27 +/- 4.24 mmHg. Late commencement of insulin therapy did not significantly affect the sensitivity of the diabetic rats to high-salt diet. The results suggest that early commencement of insulin therapy could prevent the development of high blood pressure in diabetic rats. |
| Intensifying the fight against high blood pressure Oganov, R. G., I. S. Glasunov, et al. (1988), World Health Forum 9(1): 88-91. |
| Interventions for improving adherence to treatment in patients with high blood pressure in ambulatory settings Schroeder, K., T. Fahey, et al. (2004), Cochrane Database Syst Rev(2): CD004804. Abstract: BACKGROUND: Lack of adherence to blood pressure lowering medication is a major reason for poor control of hypertension worldwide. Interventions to improve adherence to antihypertensive medication have been evaluated in randomised trials but it is unclear which interventions are effective. OBJECTIVES: To determine the effectiveness of interventions aiming to increase adherence to blood pressure lowering medication in adults with high blood pressure SEARCH STRATEGY: All-language search of all articles (any year) in the Cochrane Controlled Trials Register (CCTR), MEDLINE, EMBASE, and CINAHL in April 2002. SELECTION CRITERIA: RCTs of interventions to increase adherence to blood pressure lowering medication in adults with essential hypertension in primary care, with adherence to medication and blood pressure control as outcomes DATA COLLECTION AND ANALYSIS: Two authors extracted data independently and in duplicate and assessed each study according to the criteria outlined by the Cochrane Collaboration Handbook. MAIN RESULTS: We included 38 studies testing 58 different interventions and containing data on 15519 patients. The studies were conducted in nine countries between 1975 and 2000. The duration of follow-up ranged from two to 60 months. Due to heterogeneity between studies in terms of interventions and the methods used to measure adherence, we did not pool the results. Simplifying dosing regimens increased adherence in seven out of nine studies, with a relative increase in adherence of 8 per cent to 19.6 per cent. Motivational strategies were successful in 10 out of 24 studies with generally small increases in adherence up to a maximum of 23 per cent. Complex interventions involving more than one technique increased adherence in eight out of 18 studies, ranging from 5 per cent to a maximum of 41 per cent. Patient education alone seemed largely unsuccessful. REVIEWERS' CONCLUSIONS: Reducing the number of daily doses appears to be effective in increasing adherence to blood pressure lowering medication and should be tried as a first line strategy, although there is less evidence of an effect on blood pressure reduction. Some motivational strategies and complex interventions appear promising, but we need more evidence on their effect through carefully designed RCTs. |
| Intracellular electrolytes and high blood pressure. Membrane theory of essential hypertension Duhm, J. (1983), MMW Munch Med Wochenschr 125(45): 1045-9. |
| Inverse association of Chlamydia pneumoniae infection with high blood pressure in Japanese adults Nishimura, M., M. Ushiyama, et al. (2001), Am J Hypertens 14(1): 20-6. Abstract: To determine whether Chlamydia pneumoniae (C. pneumoniae) infection is associated with hypertension in Japanese adults, we measured serum levels of IgA (a marker of reinfection) and of IgG (a marker of previous infection) antibodies to C. pneumoniae by enzyme-linked immunosorbent assay in 112 adults including normotensive and untreated hypertensive subjects and in 117 hypertensive subjects who had been receiving treatment for more than 3 years. In 112 adults, positivity rate for IgA was lower (P <.01) in hypertensive than in normotensive or borderline hypertensive subjects. Positivity rates for IgA and IgG together, which indicate persistent infection of C. pneumoniae, were lower (P <.01) in hypertensive than in normotensive subjects. IgA levels were inversely correlated with systolic blood pressure (SBP) (r = 0.530, P =.0001) and with diastolic blood pressure (DBP) (r = 0.398, P =.0001). In the 117 hypertensive subjects treated with medication, positivity rate for IgA was lower (P <.01) in subjects with poor control than in those with good control. Positivity rates for IgA and IgG together were lower (P < 0.01) in the poor control group than in the good or fair control groups. IgA levels were correlated inversely with SBP and DBP. In both 112 adults and 117 hypertensive patients, levels of SBP or DBP were inversely associated with positivity rates for IgA and IgG together in multiple logistic regression analysis. The results suggest an inverse relationship between high blood pressure and C. pneumoniae infection in Japanese adults. |
| Investigation of high salt intake in a Nepalese population with low blood pressure Kawasaki, T., K. Itoh, et al. (1993), J Hum Hypertens 7(2): 131-40. Abstract: The relation between BP and the factors influencing an increase in BP with age were investigated in the inhabitants of two representative hilly (Kotyang: 206 men and 212 women) and suburban (Bhadrakali: 265 and 244) villages in Nepal. BP for both sexes was statistically significantly higher in Bhadrakali than in Kotyang. Neither hypertension nor elevation of BP with age for men and very few women (1.4%) with hypertension were observed in Kotyang, while 10.9% of men and 4.9% of women were found to be hypertensive in Bhadrakali. Average urinary Na excretion was 183-221 mEq/day in both villages. Urinary Na/K ratio, percentage body fat (%Fat), total protein, total cholesterol and serum Ca were statistically significantly higher in Bhadrakali than in Kotyang, and maximal oxygen uptake and serum Mg were higher in Kotyang. In spite of high salt consumption, there was no increase in BP with age in Kotyang's males, suggesting that the BP may be influenced by physical activity, fat-free mass and nutrient consumption in addition to the high sodium intake, and that extremely high physical activity and very low %Fat could serve to mute the influence of high sodium intake. |
| Involvement of fluctuating high blood pressure in the enlargement of spontaneous intracerebral hematoma Maruishi, M., T. Shima, et al. (2001), Neurol Med Chir (Tokyo) 41(6): 300-4; discussion 304-5. Abstract: The correlations between changes in blood pressure after admission and hematoma expansion were investigated in 118 patients with spontaneous intracerebral hematoma admitted within 24 hours of onset who underwent serial computed tomography. Multiple logistic regression was performed to assess correlations between hematoma enlargement and clinical characteristics on admission. Hematoma enlargement was predominantly correlated with time of onset (p = 0.01567), and not well correlated with blood pressure at admission (p = 0.07908). Serial changes in blood pressure were investigated in 57 patients admitted within 6 hours of ictus whose blood pressures were monitored every hour from admission. Wilcoxon signed-rank analysis was used to determine the relationships between hematoma enlargement and blood pressure. Patients with hematoma enlargement was significantly correlated with increased blood pressure (p = 0.0004). Increases in blood pressure after admission may be a factor in hematoma enlargement. |
| Is a rational therapy of high blood pressure possible? Brod, J. (1981), Med Klin 76(16): 447-52. |
| Is cardiovascular remodeling in patients with essential hypertension related to more than high blood pressure? A LIFE substudy. Losartan Intervention For Endpoint-Reduction in Hypertension Olsen, M. H., K. Wachtell, et al. (2002), Am Heart J 144(3): 530-7. Abstract: BACKGROUND: Blocking the renin-aldosterone-angiotensin II system has been hypothesized to induce blood pressure-dependent as well as blood pressure-independent regression of cardiovascular hypertrophy. However, the relative influence of elevated blood pressure (BP) and various neurohormonal factors on cardiovascular remodeling in hypertension is unclear. METHODS: In 43 untreated patients with hypertension with electrocardiographic left ventricular hypertrophy, we measured relative wall thickness and left ventricular mass index by echocardiography and by magnetic resonance imaging (n = 32), intima-media cross-sectional area, and distensibility of the common carotid arteries by ultrasound, media/lumen ratio of isolated subcutaneous resistance arteries by myography, and median 24-hour systolic BP (n = 40), serum insulin, and plasma levels of epinephrine, norepinephrine, renin, angiotensin II, aldosterone, and endothelin. RESULTS: In multiple regression analyses, left ventricular mass index by echocardiography (R2 = 0.14, P <.05) and by magnetic resonance imaging (R2 = 0.32, P =.001) were associated with 24-hour systolic BP, whereas relative wall thickness was associated with plasma epinephrine (R2 = 0.12, P <.05) and aldosterone (R2 = 0.10, P <.05). Intima-media cross-sectional area/height was associated with 24-hour systolic BP (beta = 0.40) and plasma epinephrine (beta = 0.43) (adjusted R2 = 0.32, P <.001), whereas carotid distensibility was associated with 24-hour systolic BP (beta = 0.40) and plasma angiotensin II (beta = -0.41) (adjusted R2 = 0.30, P <.001). Media/lumen ratio in subcutaneous resistance arteries was associated with plasma epinephrine (R2 = 0.22, P <.01). CONCLUSION: Apart from being associated with a high BP burden, cardiovascular remodeling was associated with high levels of circulating epinephrine, aldosterone, as well as angiotensin II, suggesting a beneficial effect above and beyond the effect of BP reduction when using antihypertensive agents blocking the receptors of these neurohormonal factors. |
| Is exercise good for high blood pressure? Wilcox, R. G., T. Bennett, et al. (1982), Br Med J (Clin Res Ed) 285(6344): 767-9. |
| Is high blood pressure a late manifestation of the hypertension syndrome? Neutel, J. M., D. H. Smith, et al. (1999), Am J Hypertens 12(12 Pt 3): 215S-223S. Abstract: Because hypertension has generally been defined as a disease of elevated systolic and diastolic blood pressure, the goals of treating hypertension have been simply to normalize the blood pressure. It was believed that if normal blood pressure were achieved, patients with hypertension would experience significant reductions in the incidence of associated cardiovascular events. However, studies to assess cardiovascular events in patients with hypertension have repeatedly demonstrated that reducing blood pressure results in very impressive reductions in cerebrovascular disease but in reductions of only about 16% in coronary artery disease, which is far lower than what was statistically predicted from the reductions in blood pressure. Although there are probably several reasons for the poor rate of reductions in the incidence of coronary artery disease, one of the most compelling appears to be the realization that hypertension is not simply a disease of numbers but rather a complex inherited syndrome of cardiovascular risk factors, all of which contribute to the development of heart disease in these patients. Included in the hypertension syndrome are abnormalities of lipid profile and insulin resistance, changes in renal function, endocrine changes, obesity, abnormalities of coagulation factors, and changes in the structure and function of the left ventricle and of vascular smooth muscle in the vasculature. In many patients, high blood pressure is a late manifestation of this disease process and is preceded by some or all of the associated cardiovascular risk factors. This paradigm suggests that therapeutic strategies for hypertension should be interventions that target both the hemodynamic and nonhemodynamic mechanisms of this syndrome to more completely reduce cardiovascular morbidity and mortality in patients with hypertension. |
| Is high blood pressure a psychosomatic disorder? A critical review of the evidence Davies, M. H. (1971), J Chronic Dis 24(4): 239-58. |
| Is high blood pressure an aetiological factor in epistaxis? Petruson, B., R. Rudin, et al. (1977), ORL J Otorhinolaryngol Relat Spec 39(3): 155-60. Abstract: In the present investigation, 391 men born in 1913 were examined. The blood pressure was registered in a standardized way and the subjects were questioned about epistaxis. The aim of the investigation was to analyze whether habitual nose-bleeders or subjects with recent bleedings had higher blood pressure than the other subjects in the population study. All attempts to find a correlation between epistaxis and elevated (or high) blood pressure were unsuccessful. When high blood pressure is found in a patient with nose-bleeds it is probably an incidental finding and not an aetiological factor. |
| Is high too low? A commentary by the Wisconsin State High Blood Pressure Advisory Committee Gutmann, F. D. (1985), Wis Med J 84(1): 31-3. |
| Is increased plasma viscosity a risk factor for high blood pressure? Koenig, W., M. Sund, et al. (1989), Angiology 40(3): 153-63. Abstract: Data from several epidemiologic studies have suggested that, among other variables, hematocrit and fibrinogen may constitute risk factors for high blood pressure. As part of a population survey for cardiovascular risk factors, plasma viscosity and hemoglobin were measured. Blood pressure was determined under standardized conditions according to the recommendations of the AHA. A two-stage age-sex-stratified cluster sample of 5,312 persons, aged twenty-five to sixty-four years, was selected from a mixed urban/rural target population of 282,279 (total population approximately 533,000). A net response of 79.3% was achieved. Multiple logistic regression analyses including plasma viscosity, hemoglobin, body mass index, alcohol consumption, smoking behavior, and total serum cholesterol as independent variables were run controlling for both age and sex. Plasma viscosity appeared as a significant main effect in all analyses and demonstrated the strongest association with high blood pressure next to body mass index. Whether this association implies a causal relationship cannot be answered from cross-sectional data. However, even if plasma hyperviscosity represents a secondary phenomenon in hypertension, it might be of prognostic relevance. There is evidence that increased plasma viscosity may contribute to myocardial hypertrophy. Therefore hypertensives with impaired blood fluidity might constitute a subgroup at particular risk for cardiovascular complications. When antihypertensive drugs are selected, their influence on blood viscosity should be taken into account. |
| Is lead considered as a risk factor for high blood pressure during menopause period among Saudi women? Al-Saleh, I., N. Shinwari, et al. (2005), Int J Hyg Environ Health 208(5): 341-56. Abstract: This case-control study was designed to examine the association between blood lead levels and high blood pressure in a restricted subpopulation, Saudi women who were 45-93-year old, during or after menopausal period and not occupationally exposed to lead. Blood lead levels were assessed in 100 women with hypertension and 85 control subjects. Lead concentrations were measured in the whole blood using flameless atomic absorption spectrophotometry. Blood pressure measurements were performed according to the World Health Organization recommendations. Results revealed that the mean blood lead levels for hypertensive were 47.52+/-39.26 and 45.59+/-28.55 microg/l for controls. Participants were classified according to the median of blood lead levels in order to compute odds ratios. After controlling a number of potential confounding variables, the multiple logistic regression analysis revealed that women with blood lead levels of > or = 38.6 microg/l were 5.27 times more likely to be hypertensive than those with blood lead levels of < 38.6 microg/l, but of borderline significance (p = 0.06). Although such observation might support the hypothesis that the depletion of lead from bones during menopause increases blood lead levels placing women at increased risk for high blood pressure, there is a need for further studies with larger number of subjects. A number of risk factors, which were suspected to influence blood lead levels, were also investigated. Use of Kohl, duration of its use, osteoporosis disease and intake of calcium supplements were significantly associated with blood lead levels. |
| Is the effect of low birth weight on cardiovascular mortality mediated through high blood pressure? Koupilova, I., D. A. Leon, et al. (1999), J Hypertens 17(1): 19-25. Abstract: OBJECTIVE: To explore whether the inverse association between birth weight and mortality from circulatory diseases is mediated through blood pressure in men aged 50-75 years. DESIGN: Cohort study with retrospectively collected data on size at birth. SUBJECTS AND SETTING: The study included 1334 men born during 1920-1924, living in Uppsala, Sweden, who were examined at the ages of 50 and 60 years, and followed-up to the end of 1995. MAIN OUTCOME MEASURES: Mortality from circulatory diseases based on routine death registration. RESULTS: Birth weight showed a specific, inverse association with mortality from circulatory diseases: the rate ratio was 0.67 (95% confidence interval 0.50 to 0.89) per 1000 g increase in birth weight. This association was not appreciably affected by adjustment for sociodemographic characteristics or smoking, but was strengthened slightly by adjustment for body mass index at the ages of 50 and 60 years. Adjustment for systolic blood pressure at the age of 50 years only slightly reduced the strength of the inverse association between birth weight and mortality from ischaemic heart disease, and did not affect the inverse association between birth weight and mortality from stroke. Adjustments for systolic and diastolic blood pressure and hypertension treatment at the ages of 50 and 60 years did not reduce the strength of the association between birth weight and mortality from circulatory diseases at the age of 60-75 years. CONCLUSIONS: The inverse association between birth weight and mortality from circulatory diseases in men aged 50-75 years is independent of adult sociodemographic characteristics, smoking and adult obesity and does not seem to be mediated through an increased blood pressure in those with low birth weight. |
| Is the humoral renal antihypertensive activity of the spontaneously hypertensive rat (SHR) reset to the high blood pressure? Karlstrom, G., G. Bergstrom, et al. (1991), Acta Physiol Scand 141(4): 517-30. Abstract: The kidneys have a humoral antihypertensive system, located in the renal medulla and presumably antagonizing the pro-hypertensive renin-angiotensin system. Medullipin I and II and maybe platelet activating factor (PAF), seem to be the mediators of this system, known to be activated after reversal of renovascular hypertension or when the perfusion pressure to a normotensive kidney is suddenly elevated. The present study was undertaken to investigate whether this system is functioning also in the spontaneously hypertensive rat (SHR), and if it is then reset in proportion to the increased mean arterial pressure (MAP). Isolated kidneys from spontaneously hypertensive rats and from Wistar Kyoto rats (WKY) were cross-perfused in vivo from anaesthetized intact Wistar Kyoto rat 'donors'. After 30 min of perfusion at 100 mmHg the perfusion pressure to the isolated kidneys were, for 60 min, either kept unaltered at 100 mmHg or, for the Wistar Kyoto rat kidneys, increased to 150-200 mmHg and, for the spontaneously hypertensive rat kidneys, raised to 200 or 250 mmHg. The results show that the humoral antihypertensive system is present also in spontaneously hypertensive rat kidneys, but is here reset upwards to or even beyond the elevated MAP level. Furthermore, all mean arterial pressure reductions caused by high-pressure perfusion of Wistar Kyoto and spontaneously hypertensive rat kidneys were accompanied by reductions in heart rate (HR) in the 'donors', in agreement with previous observations after reversing renal hypertension and after i.v. medullipin I injection. In fact, in spontaneously hypertensive rat kidneys, the 'incretory' depressor mechanism appears to be more markedly reset upwards than is the 'excretory' depressor mechanism inherent in pressure diuresis with consequent salt-volume elimination. In conclusion spontaneously hypertensive rats, like Wistar Kyoto rats and Wistar rats, have a humoral antihypertensive system in the kidneys, but it is reset upwards even beyond the elevated mean arterial pressure level in spontaneously hypertensive rats. The combination of a depressor response and reduced heart rate in the 'donors' renders further evidence that the medullipins are the principal, though probably not the only, humoral antihypertensive factors released from the cross-circulated kidneys. |
| Is there a different dietetic pattern depending on self-knowledge of high blood pressure? Tormo, M. J., C. Navarro, et al. (2000), Eur J Epidemiol 16(10): 963-71. Abstract: This cross-sectional study describes the dietary pattern seen at recruitment in a large Spanish cohort comprising 41,451 people (aged 30-69 years) according to high blood-pressure status. We provide information on adjusted mean daily intake of foods and nutrients, by means of a dietary history, from those people self-reported as having high blood pressure as well as from those self-reported as normotensive but having, after actual blood-pressure measurement, systolic or diastolic blood pressures of > or = 160/95 mmHg. Although with small differences in mean intake people who self-reported high blood pressure have a higher consumption of potatoes, vegetables, vitamin C and E; furthermore, men reported an increased intake of fruit, meat, fish, proteins, dietary fibre, beta-carotene and alcohol, and women tended to consume less alcohol, lipids and cholesterol but more proteins, carbohydrates and dietary fibre. Almost no differences are found in fatty acid intake. This pattern is reversed among those self-reported as normotensive but with high blood pressure after actual measurement. We conclude that in this large prospective cohort, awareness or not of having high blood pressure at recruitment is associated with a differential dietary pattern. |
| Ischemic heart disease and high blood pressure Hilden, T. and H. Ibsen (1988), Ugeskr Laeger 150(19): 1140-2. |
| Isoflavonoids do not inhibit in vivo lipid peroxidation in subjects with high-normal blood pressure Hodgson, J. M., I. B. Puddey, et al. (1999), Atherosclerosis 145(1): 167-72. Abstract: The isoflavonoids genistein and daidzein have been shown to have antioxidant activity in vitro, but their effects on in vivo oxidation have not been assessed. The newly described F2-isoprostanes are believed to currently represent the best available marker of in vivo lipid peroxidation. Therefore we have assessed the effects of a 55 mg daily isoflavonoid supplement on urinary F2-isoprostane concentrations in subjects with high-normal blood pressure (BP). A total of 59 subjects completed an 8-week parallel design, randomized, double blind, and placebo-controlled study. F2-isoprostanes, isoflavonoids and creatinine were measured in 24-h urine samples taken at baseline and at the end of the intervention. There were significant increases in urinary excretion of genistein (5.22+/-0.75 mg/day, P < 0.0001) and daidzein (2.53+/-0.43 mg/day, P < 0.0001) in the group taking the isoflavonoid supplement. Creatinine excretion was significantly correlated with F2-isoprostanes at baseline (r = 0.45, P < 0.01). After adjustment for baseline values, there was no significant difference between groups in creatinine adjusted post-intervention F2-isoprostane concentrations (P = 0.74). In addition, changes in genistein and daidzein excretion were not significantly correlated with changes in F2-isoprostanes in the isoflavonoid treatment group. These results are not consistent with the suggestion that the two soy derived isoflavonoids have in vivo antioxidant activity at a level of intake achievable by dietary means and in subjects with high-normal BP. |
| Isolated systolic hypertension: a different kind of high blood pressure Maio, A. (1994), Nebr Med J 79(4): 105-6. Abstract: Isolated systolic hypertension is a distinct disease entity associated with serious morbidity and mortality, in particular, stroke. The mechanism of systolic hypertension appears to be a reduction in arterial compliance. Identification of patients at greatest risk is paramount. A simple nonpharmacologic or pharmacologic intervention can decrease isolated systolic hypertension, enhance quality of life and prevent major cardiovascular and cerebrovascular complications. |
| Isolated systolic hypertension: data from the European Working Party on High Blood Pressure in the Elderly O'Malley, K., P. McCormack, et al. (1988), J Hypertens Suppl 6(1): S105-8. Abstract: The European Working Party on High Blood Pressure in the Elderly study (EWPHE) was a placebo-controlled, double-blind, inter-patient assessment of diuretic treatment in hypertensive patients aged 60 years or more. Of the 840 patients included in the study 247 had isolated systolic hypertension (systolic blood pressure greater than or equal to 160 and diastolic blood pressure less than or equal to 95 mmHg). In those (n = 120) randomized to active treatment (diazide-hydrochlorothiazide with triamterene +/- methyldopa) blood pressure after 3 years was, on average, 19/8 mmHg lower than in the placebo group (n = 119) and after 5 years the difference was 9/7 mmHg. Data on mortality and morbidity were insufficient for firm conclusions to be drawn. The data are presented here only to communicate the trends observed and to provide information that may be useful in the design of future trials. The trends observed for cardiac mortality, terminating non-fatal events (including severe heart failure) and combined fatal and non-fatal cardiovascular events follow a similar pattern to that observed in the trial overall, in that active treatment appeared to confer benefit. However, in the case of isolated systolic hypertension none of these differences between active and placebo treatment achieved statistical significance. We conclude that, given the epidemiological data incriminating systolic hypertension as a risk factor and the data presented here, a rigorous assessment of the value of treating isolated systolic hypertension is justified. |
| Isolation of a chromosome 1 region that contributes to high blood pressure and salt sensitivity Iwai, N., Y. Tsujita, et al. (1998), Hypertension 32(4): 636-8. Abstract: Linkage analyses in the spontaneously hypertensive rat (SHR) suggest that a gene involved in blood pressure regulation may be located on rat chromosome 1, in the Sa region. To confirm this possibility, we replaced a region of chromosome 1 in the Wistar-Kyoto rat (WKY) defined by the markers D1Mit3 and MTPA with the corresponding chromosome segment from SHR. Genotyping using 65 polymorphic microsatellite markers throughout the entire genome confirmed the congenic status of this new strain designated WKY. SHR-D1Mit3/Rat57. In male WKY.SHR-D1Mit3/Rat57, mean blood pressures in the daytime and in the nighttime assessed by radiotelemetry were significantly higher than those in male progenitor WKY. Moreover, salt loading significantly increased the mean blood pressure in male WKY.SHR-D1Mit3/Rat57 but not in male progenitor WKY. The present study confirmed the existence of a gene that contributes to high blood pressure and salt sensitivity in this chromosomal segment. This congenic strain represents a new animal model for fine mapping and characterization of the gene in this region involved in salt-sensitive hypertension. |
| Isosorbide 5-mononitrate reverses high blood pressure in NG-nitro-L-arginine methyl ester treated rats Albino-Teixeira, A. and P. Soares-da-Silva (1994), Gen Pharmacol 25(7): 1329-36. Abstract: 1. The present study has evaluated the effect of iosorbide 5-mononitrate (IS-5-MN) and L-arginine on blood pressure profile during chronic administration of the nitric oxide (NO) synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME). 2. After a 7 day period of stabilization, normotensive male Wistar rats (n = 10) were selected and given L-NAME (50 micrograms/ml) in drinking water. Control rats (n = 10) were studied simultaneously for direct comparison of cardiovascular parameters. Blood pressure (systolic, SBP; diastolic, DBP) and heart rate were measured using a photoelectric tail cuff pulse detector; SBP and DBP were, in normotensive rats 106 +/- 2 and 78 +/- 2 mmHg (n = 10), respectively. The average water consumption per animal was about 35 ml/day resulting in a mean intake of L-NAME of about 10 mg/kg/day. 3. Twenty four hours after exposure to L-NAME, both SBP and DBP were found to be increased by 20 mm Hg; heart rate slightly decreased. During the next 13 days both SBP and DBP increased progressively reaching 170 +/- 3 and 116 +/- 3 mm Hg, respectively. 4. On day 14, six animals of either group were sacrificed and the heart, kidneys, liver, spleen, mesenteric and caudal arteries, brain stem, hypothalamus and parietal cortex were taken from determination of noradrenaline and dopamine content; blood from the renal vein was also collected and plasma concentrations of noradrenaline, adrenaline and 3,4-dihydroxyphenylethylglycol (DOPEG) determined.(ABSTRACT TRUNCATED AT 250 WORDS) |
| I've heard that eating foods high in potassium can help lower blood pressure and prevent stroke. But can too much potassium be dangerous? Aaronson, K. (2000), Health News 6(12): 10. |
| JNC 7--it's more than high blood pressure Kottke, T. E., R. J. Stroebel, et al. (2003), Jama 289(19): 2573-5. |
| JNC guidelines: is the message getting through? Joint National Commission on Detection, Evaluation, and Treatment of High Blood Pressure Lenfant, C. (1997), Jama 278(21): 1778-9. |
| Job status and high-effort coping influence work blood pressure in women and blacks Light, K. C., K. A. Brownley, et al. (1995), Hypertension 25(4 Pt 1): 554-9. Abstract: Work-related stress has been associated with an increased risk of hypertension and more severe cardiovascular problems in white men but has been less studied in women and black men. To determine whether the trait of high-effort coping (John Henryism) was related to higher blood pressure during work and laboratory challenges, we studied a biracial sample of 72 men and 71 women working full time outside the home who underwent ambulatory blood pressure monitoring for one 8-hour workday. This was followed by laboratory monitoring of blood pressure during resting baseline and five brief stressors. Women who were high-effort copers and had high status jobs had higher diastolic pressures at work and in the lab than other women; their pressure levels did not differ from those of men, but other women had lower pressures than men. In blacks, the same combination of high-effort coping plus high job status was similarly associated with high work and laboratory diastolic pressure, as well as higher work systolic pressure. The trait of high-effort coping was observed in the large majority (71%) of the women and blacks who had achieved high status jobs but was seen in a minority (36%) of white men with high status jobs and was unrelated to increased blood pressure in the latter group. |
| Keeping high blood pressure on the run. Pharmacy's big part in hypertension control Williams, R. L. (1980), Am Pharm NS20(2): 26-35. |
| Kidney disease as a risk factor for development of cardiovascular disease: a statement from the American Heart Association Councils on Kidney in Cardiovascular Disease, High Blood Pressure Research, Clinical Cardiology, and Epidemiology and Prevention Sarnak, M. J., A. S. Levey, et al. (2003), Hypertension 42(5): 1050-65. |
| Labeling of participants in high blood pressure screening programs. Implications for blood cholesterol screenings Lefebvre, R. C., K. G. Hursey, et al. (1988), Arch Intern Med 148(9): 1993-7. Abstract: Screening programs have expanded to identify the many persons who are unaware of their high blood cholesterol level and thus are at an increased risk for coronary heart disease. These programs bring both potential benefits and potential risks to the participant. One potential risk is that of iatrogenic effects of learning one's risk status, often referred to as the "labeling phenomenon." Research that has addressed the labeling phenomenon in blood pressure screening programs has important implications for blood cholesterol screenings. Detrimental effects on screening participants are possible, but they can be attenuated by careful attention to characteristics of the debriefing and counseling that should be included in screening protocols. |
| Laboratory assessment of the hypertensive individual. Value of the main guidelines for high blood pressure Reis, R. S., I. J. Bensenor, et al. (1999), Arq Bras Cardiol 73(2): 201-10. Abstract: OBJECTIVE: To determine if abnormal laboratory findings are more common in individuals with hypertension and in those with other risk factors, such as obesity, smoking and alcohol ingestion. METHODS: A study was carried out in the general outpatient clinics of a university hospital (145 individuals without previous diagnosis of hypertension) and the following variables were assessed: high blood pressure (as defined by the VI Joint National Committee on Prevention, Detection and Treatment of High Blood Pressure--VI JNC), obesity calculated using body mass index (BMI), tobacco use, and alcoholic ingestion. The laboratory examinations consisted of the following tests: hemogram, glycemia, uric acid, potassium, total/HDL-fraction cholesterol, triglycerides, calcium and creatinine. RESULTS: High blood pressure was not associated with a higher number of abnormal laboratory tests. Hypertensive individuals with a BMI > or = 25 kg/m2 or normotensive obese individuals, however, had a higher frequency of diabetes (12X), hypertriglyceridemia (3X), and hypercholesterolemia (2X), as compared with hypertensive individuals with BMI < 25 kg/m2 and preobese/normal weight normotensive individuals. CONCLUSION: High blood pressure is not associated with a higher frequency of abnormal laboratory tests. The association of high blood pressure and obesity, however, increases the detection of diabetes and dyslipidemias. |
| Lacidipine reduces high blood pressure and the target organ damage induced by high fructose diet in rats Cosenzi, A., E. Bernobich, et al. (1999), J Hypertens 17(7): 965-71. Abstract: OBJECTIVE: Normotensive rats fed a high fructose diet (HFD) develop hypertriglyceridemia, hyperinsulinemia and hypertension. The glomerular changes observed in the kidneys of these animals are similar to those observed in diabetic rats. The aim of this study was to evaluate whether lacidipine could be effective not only in preventing, but also in inducing the regression of hypertension, and renal and cardiac damage in rats fed HFD. METHODS: Thirty male Wistar-Kyoto (WKY) rats received HFD for 1 month; thereafter, five rats were sacrificed (Group 1) and the other 25 rats were divided into three groups: Group 2 (five rats) received HFD plus placebo, Group 3 (10 rats) HFD plus lacidipine 3 mg/kg per day, and Group 4 (10 rats) HFD plus hydralazine 10 mg/kg per day. At the end of the second month all animals were sacrificed. Kidneys and hearts were immediately removed. Renal deposits of collagen I, collagen IV, fibronectin and cardiac deposits of collagen III were assessed by means of immunohistochemistry. RESULTS: In the rats receiving HFD plus placebo, blood pressure was increased after the first and the second month of diet. This increase was reversed by lacidipine and hydralazine but, although both drugs normalized blood pressure, only lacidipine was effective in reducing renal and cardiac damage. CONCLUSIONS: These data suggest that lacidipine is effective in reversing hypertension and reducing target organ damage induced by HFD. Moreover, this protective effect on target organs appears to be not simply a consequence of blood pressure reduction, but seems to be connected to the type of hypotensive drug administered. |
| Lack of blood pressure effect with calcium and magnesium supplementation in adults with high-normal blood pressure. Results from Phase I of the Trials of Hypertension Prevention (TOHP). Trials of Hypertension Prevention (TOHP) Collaborative Research Group Yamamoto, M. E., W. B. Applegate, et al. (1995), Ann Epidemiol 5(2): 96-107. Abstract: Phase I of the Trials of Hypertension Prevention (TOHP) was a randomized, multicenter investigation that included double-blind, placebo-controlled testing of calcium and magnesium supplementation among 698 healthy adults (10.5% blacks and 31% women) aged 30 to 54 years with high-normal diastolic blood pressure (DBP) (80 to 89 mm Hg). Very high compliance (94 to 96% by pill counts) with daily doses of 1 g of calcium (carbonate), 360 mg of magnesium (diglycine), or placebos was corroborated for the active supplements by significant net increases in all urine and serum compliance measures in white men and for urine compliance measures in white women. Overall, neither calcium nor magnesium produced significant changes in blood pressure at 3 and 6 months. Analyses stratified by baseline intakes of calcium, magnesium, sodium, or initial blood pressures also showed no effect of supplementation. These analyses suggested that calcium supplementation may have resulted in a DBP decrease in white women and that response modifiers in this subgroup might have included lower initial urinary calcium levels, urinary sodium levels, or lower body mass index. However, overall analyses indicated that calcium and magnesium supplements are unlikely to lower blood pressure in adults with high-normal DBP. The subgroup analyses, useful to formulate hypotheses, raise the possibility of a benefit to white women, which requires testing in future trials. |
| Lack of control of high blood pressure and treatment recommendations in Canada Khan, N., A. Chockalingam, et al. (2002), Can J Cardiol 18(6): 657-61. Abstract: BACKGROUND: Hypertension is a major risk factor for death that affects many Canadians, but only 16% of hypertensive Canadians are treated and have their hypertension controlled. While the control rate is very low, the 2001 Canadian Hypertension Recommendations do not recommend that low risk hypertensive patients be started on pharmacotherapy, and pharmacotherapy is not recommended for people for whom there is no demonstrable benefit from randomized, controlled trails. OBJECTIVES: To determine the proportion of hypertensive patients who are appropriately managed according to the 2001 Canadian Hypertension Recommendations. METHODS: Data from the Canadian Heart Health Survey, which surveyed a cross-sectional population (n=23,129) between 1986 and 1992, were used to determine the proportion of nondiabetic hypertensive patients who are managed according to the 2001 Canadian Hypertension Recommendations. Hypertensive patients not recommended to receive pharmacotherapy include those without risk factors and target organ damage, with a diastolic blood pressure of 90 to 99 mmHg and a systolic blood pressure of less than 160 mmHg. People with diastolic blood pressures of less than 90 mmHg who have systolic blood pressures of 140 to 159 mmHg are also not recommended to have pharmacotherapy. Patients prescribed antihypertensive therapy who had blood pressure controlled to less than 140/90 mmHg were assessed as having their hypertension managed appropriately, as were those who were not treated and were not recommended to be prescribed treatment. RESULTS: There were 58,813 (1.7%) hypertensive patients who did not have target organ damage or additional risk factors, and had a systolic blood pressure of less than 160 mmHg and a diastolic blood pressure between 90 and 99 mmHg. Twenty four per cent of hypertensive persons (831,787) had a systolic blood pressure of 140 to 160 mmHg and a diastolic blood pressure of less than 90 mmHg. About 25% (23.6%+1.7%) of hypertensive Canadians in the Canadian Heart Health Survey are not recommended to be prescribed antihypertensive therapy according to the 2001 Canadian Hypertension Recommendations. Sixteen per cent of hypertensive patients were treated and had their blood pressures controlled (blood pressure less than 140/90 mmHg). Therefore, about 41% (ie, 16%+25%) of hypertensive patients are appropriately managed according to the 2001 Canadian Hypertension Recommendations. CONCLUSIONS: The results of the Canadian Heart Health survey indicate that there are a striking number of Canadians with untreated high blood pressure (59%) who probably do not have their hypertension managed according to the 2001 Canadian Hypertension Recommendations. Greater efforts are required to identify people with hypertension, and to ensure that they are managed according to the best available evidence. |