| For medical practitioners and the general public - High Blood Pressure Journal Article Catalog. |
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| Effects of immunosympathectomy on development of high blood pressure in genetically hypertensive rats Clark, D. W. (1971), Circ Res 28(3): 330-6. |
| Effects of isoflavonoids on blood pressure in subjects with high-normal ambulatory blood pressure levels: a randomized controlled trial Hodgson, J. M., I. B. Puddey, et al. (1999), Am J Hypertens 12(1 Pt 1): 47-53. Abstract: Vegetarian diets lower blood pressure (BP), but attempts to identify dietary components responsible have been unsuccessful. Isoflavonoids are commonly consumed as part of vegetarian diets. The objective of this study was to assess the effect of isoflavonoid supplementation on BP. Fifty-nine subjects with high-normal range systolic BP completed a randomized, double blind, placebo-controlled trial of two-way parallel design and 8 weeks duration. One tablet containing 55 mg of isoflavonoids, including 30 mg of genistein, 16 mg of biochanin A (a genistein precursor), 1 mg of daidzein, and 8 mg of formononetin (a daidzein precursor), or one placebo tablet, was taken daily with the evening meal. Significant increases in urinary excretion of genistein (5.22 mg/day, 95% CI: 3.72, 6.72) and daidzein (2.53 mg/day, 95% CI: 1.66, 3.40) were observed in the group taking the isoflavonoid supplement. There were no significant changes in isoflavonoid excretion in the placebo group. Clinic BP was measured at two visits, and ambulatory BP monitoring was performed over one 24-h period, at baseline and postintervention. There was no significant difference between groups, after adjustment for baseline values, in postintervention clinic supine BP (systolic 1.2 mm Hg, 95% CI: -2.3, 4.7; diastolic 0.6 mm Hg, 95% CI: -1.9, 2.5), clinic erect BP (systolic 1.7 mm Hg, 95% CI: -4.0, 8.4; diastolic 0.4 mm Hg, 95% CI: -2.4, 3.2), or 24-h ambulatory BP (systolic -1.4 mm Hg, 95% CI: -4.4, 1.6; diastolic -0.8 mm Hg, 95% CI: -2.3, 0.7). Adjustment for age, gender, and weight change did not alter the result. Therefore, these results do not support the hypothesis that isoflavonoids, and genistein in particular, are major contributors to the BP lowering effect of vegetarian diets. |
| Effects of isradipine or enalapril on blood pressure in salt-sensitive hypertensives during low and high dietary salt intake. MIST II Trial Investigators Chrysant, S. G., A. B. Weder, et al. (2000), Am J Hypertens 13(11): 1180-8. Abstract: This large multicenter study, tested the antihypertensive effects of isradipine, a dihydropyridine calcium channel blocker and enalapril, an angiotensin-converting enzyme inhibitor, in salt-sensitive hypertensive patients under low and high salt intake diets. After a 3-week (weeks -9 to -6) of ad lib salt diet, those patients who had a sitting diastolic blood pressure (SDBP) of > or =95 but < or =115 mm Hg qualified to enter a 3-week (weeks -6 to -3) placebo run-in low salt diet (50 to 80 mmol Na+/day). Then high salt (200 to 250 mmol Na+/day) was added to the placebo treatment for 3 weeks (weeks -3 to 0). Those patients who demonstrated an increase in SDBP > or =5 mm Hg from the low to high salt diet were considered salt sensitive and were randomized into a 4-week (weeks 0 to 4) double-blind treatment period of either isradipine 2.5 to 10 mg twice a day, enalapril 2.5 to 20 mg twice a day, or placebo. Then they entered a 3-week (weeks 4 to 7) placebo washout phase of low salt diet (50 to 80 mmol Na+/day). After week 7 and while the low salt diet was continued the patients were restarted on their double-blind treatment for 4 more weeks (weeks 7 to 11) and the study was completed. Of 1,916 patients screened, 464 were randomized into the double-blind treatment phase and 397 completed the study. Both isradipine and enalapril decreased the sitting systolic blood pressure (SSBP) and SDBP during the high salt diet, to a similar degree, whereas enalapril caused a greater reduction in SSBP and SDBP than isradipine during the low salt diet (11.3 +/- 1.2/7.7 +/- 0.7 mm Hg v 7.7 +/- 0.9/4.8 +/- 0.6 mm Hg, mean +/- SEM, respectively, P <.02). Within drugs, the effect of isradipine on blood pressure (BP) was higher during the high than the low salt diet (14.9 +/- 1.5 v 7.6 +/- 1.3 mm Hg for SSBP and 10.1 +/- 0.6 v 4.8 +/- 0.9 mm Hg for SDBP, P <.001), but enalapril exerted a similar effect during both diets. Because salt restriction lowered both SSBP and SDBP, the lowest BP achieved with both drugs were during the salt restriction phase. |
| Effects of long-term high-dose labetalol on blood pressure in patients with severe hypertension resistant to previous therapy Kristensen, B. O. and E. la Cour Petersen (1980), Postgrad Med J 56 Suppl 2: 57-9. |
| Effects of low sodium diet versus high sodium diet on blood pressure, renin, aldosterone, catecholamines, cholesterols, and triglyceride Jurgens, G. and N. A. Graudal (2004), Cochrane Database Syst Rev(1): CD004022. Abstract: BACKGROUND: One of the controversies in preventive medicine is, whether a general reduction in sodium intake can decrease the blood pressure of a population and thereby reduce cardiovascular mortality and morbidity. In recent years the debate has been extended by studies indicating that reducing sodium intake has effects on the hormone and lipid profile. OBJECTIVES: To estimate the effects of low sodium versus high sodium intake on systolic and diastolic blood pressure (SBP and DBP), plasma or serum levels of renin, aldosterone, catecholamines, cholesterol and triglycerides. SEARCH STRATEGY: "MEDLINE" and reference lists of relevant articles were searched from 1966 through December 2001. SELECTION CRITERIA: Studies randomising persons to low sodium and high sodium diets were included if they evaluated at least one of the above outcome parameters. DATA COLLECTION AND ANALYSIS: Two authors independently extracted the data, which were analysed by means of Review Manager 4.1. MAIN RESULTS: In 57 trials of mainly Caucasians with normal blood pressure, low sodium intake reduced SBP by -1.27 mm Hg (CI: -1.76; -0.77)(p<0.0001) and DBP by -0.54 mm Hg (CI: -0.94; -0.14) (p = 0.009) as compared to high sodium intake. In 58 trials of mainly Caucasians with elevated blood pressure, low sodium intake reduced SBP by -4.18 mm Hg (CI: -5.08; - 3.27) (p < 0.0001) and DBP by -1.98 mm Hg (CI: -2.46; -1.32) (p < 0.0001) as compared to high sodium intake. The median duration of the intervention was 8 days in the normal blood pressure trials (range 4-1100) and 28 days in the elevated blood pressure trials (range 4-365). Multiple regression analyses showed no independent effect of duration on the effect size. In 8 trials of blacks with normal or elevated blood pressure, low sodium intake reduced SBP by -6.44 mm Hg (CI: -9.13; -3.74) (p < 0.0001) and DBP by -1.98 mm Hg (CI: -4.75; 0.78) (p = 0.16) as compared to high sodium intake. The magnitude of blood pressure reduction was also greater in a single trial in Japanese patients. There was also a significant increase in plasma or serum renin, 304% (p < 0.0001), aldosterone, 322%, (p < 0.0001), noradrenaline, 30% (p < 0.0001), cholesterol, 5.4% (p < 0.0001) and LDL cholesterol, 4.6% (p < 0.004), and a borderline increase in adrenaline, 12% (p = 0.04) and triglyceride, 5.9% (p = 0.03) with low sodium intake as compared with high sodium intake. REVIEWER'S CONCLUSIONS: The magnitude of the effect in Caucasians with normal blood pressure does not warrant a general recommendation to reduce sodium intake. Reduced sodium intake in Caucasians with elevated blood pressure has a useful effect to reduce blood pressure in the short-term. The results suggest that the effect of low versus high sodium intake on blood pressure was greater in Black and Asian patients than in Caucasians. However, the number of studies in black (8) and Asian patients (1) was insufficient for different recommendations. Additional long-term trials of the effect of reduced dietary sodium intake on blood pressure, metabolic variables, morbidity and mortality are required to establish whether this is a useful prophylactic or treatment strategy. |
| Effects of protoveratrine on high blood pressure levels. Andrial Rodriguez, A., C. Taboada Millas, et al. (1957), Arch Med Cuba 8(1): 5-11. |
| Effects of pulmonary edema on regional blood volume and red blood cell transit time. Comparison of high pressure and oleic acid-induced edema Tsang, J. Y., J. S. Montaner, et al. (1986), J Clin Invest 77(6): 1780-5. Abstract: The present study was designed to determine the effects of pulmonary vascular pressure, vascular injury, and pulmonary edema on regional blood volume (Vr) and regional red blood cell (RBC) transit time (Tr) in the lung. The experiments were carried out in 15 dogs. Six served as controls, six had oleic acid-induced pulmonary edema (OAPE), and three had high pressure pulmonary edema (HPPE). Regional blood flow (Qr) was measured with 99mTc macroaggregates, Vr with 51Cr homologous RBC, and regional transit time was calculated (Vr/Qr). The dogs were killed, and the lungs removed and sampled completely. Regional extravascular lung water (EVLW) was measured in grams per gram of dry lung and ranged from 3.7 +/- 1.1 in the control group to 6.0 +/- 1.3 in OAPE and 5.6 +/- 0.6 in HPPE. The data show that in normal lungs, increased Qr was associated with a recruitment of blood volume. In OAPE, data show that regional blood volume was decreased and that vascular injury and edema formation interfered with a further increase in Vr as Qr increased. In HPPE, Vr has already fully distended and it changed little with increased blood flow. We conclude that oleic acid-induced pulmonary injury and edema interfere with vascular recruitment and shorten regional RBC transit times. HPPE, on the other hand, is associated with normal regional RBC transit times because the vessels are fully recruited. |
| Effects of qigong on blood pressure, high-density lipoprotein cholesterol and other lipid levels in essential hypertension patients Lee, M. S., M. S. Lee, et al. (2004), Int J Neurosci 114(7): 777-86. Abstract: This study investigated the effectiveness of Qigong on blood pressure and several blood lipids, such as high-density lipoprotein (HDL) cholesterol, Apolipoprotein A1 (APO-A1), total cholesterol (TC), and triglycerides (TG) in hypertensive patients. Thirty-six patients were randomly divided into either the Qigong group, or a wait-listed control group. Blood pressures decreased significantly after eight weeks of Qigong. The levels of TC, HDL, and APO-A1 were changed significantly in the Qigong group post-treatment compared with before treatment. In summary. Qigong acts as an antihypertensive and may reduce blood pressure by the modulation of lipid metabolism. |
| Effects of rapid infusion with high pressure and large-bore i.v. tubing on red blood cell lysis and warming Mateer, J. R., B. W. Perry, et al. (1985), Ann Emerg Med 14(10): 966-9. Abstract: A prototype large-bore intravenous tubing was developed and tested. Mean flow rates for blood (Hct 45%) and tap water were determined for several catheters at 600 mm Hg, 300 mm Hg, and gravity flow and were statistically analyzed by calculating the 95% confidence intervals. The degree of hemolysis during high pressure and flow was determined by measuring the plasma free hemoglobin using the spectrophotometric method. To determine if cold banked blood can be adequately warmed at high flow rates, thermocouples were used to measure the blood temperature before and after rapid infusion through a blood warmer. Results included maximum flow rates of 1,764 mL/min for tap water, and 1,714 mL/min for blood (Hct 45%) at 600 mm Hg through the large-bore tubing and an 8.5-F catheter. Flow rates for other pressure and catheter combinations were tabulated. The plasma-free hemoglobin increased slightly compared to controls with high pressure (less than or equal to 600 mm Hg) and flow rates. The increase correlated with less than 1% red blood cell lysis in all trials. When 13 C blood was infused through a warmer, blood temperature increased to 25.3 C at the maximum flow rate of 732 mL/min. Slightly higher heat gain resulted with slower infusion rates. We conclude that the prototype large-bore tubing and up to 600 mm Hg pressure provide rapid flow rates without significant hemolysis. Blood warming may be inadequate at higher flow rates. |
| Effects of sex on differences in awareness, treatment, and control of high blood pressure Plasencia, A., A. M. Ostfeld, et al. (1988), Am J Prev Med 4(6): 315-26. Abstract: Our purpose was to explain the reasons for sex differentials in the awareness, treatment, and control of hypertension by identifying major social and behavioral predictors of these three sequential stages of high blood pressure control. We analyzed data on all 1,433 hypertensive subjects from the First Connecticut Blood Pressure Survey. Hypertensive women were more likely than hypertensive men to be aware of their high blood pressure (odds ratio = 1.40; confidence interval = 1.10-1.79) and to have controlled levels of blood pressure (odds ratio = 1.62; confidence interval = 1.08-2.44). Men and women who were aware of their hypertension were equally likely to be treated. Sex still explained differences in awareness and control of hypertension after adjusting for other significant variables. We conclude that sex is an important predictive covariate for adjustment in explaining differences in awareness and control of high blood pressure. Health care professionals should be aware of the differential role of sex when informing and treating hypertensive patients. |
| Effects of sympathectomy on the blood pressure of young Wistar rats fed with high-sucrose diet Yao, K. H., Y. R. Qian, et al. (2003), Zhonghua Er Ke Za Zhi 41(3): 219-22. Abstract: OBJECTIVE: Diet is an important factor influencing blood pressure and, increases in dietary carbohydrate intake can raise blood pressure in adult rats. A previous study showed that the blood pressure of the rats fed with high-carbohydrate was 5-20 mmHg higher than that of control rats. While the mechanism involved is not clear. This study aimed to investigate the effects of high-sucrose intake on blood pressure of young Wistar rats and the role that sympathetic nerve system in the process. METHODS: Male neonatal Wistar rats were performed sympathectomy operation with 6-hydroxydopamine (6-OHDA) and then divided into four groups: (1) 0.1% VitC saline-common diet group (VN), (2) 0.1% VitC saline-high sucrose (VS), (3) 6-OHDA-common diet group (OHN) and (4) 6-OHDA-high sucrose (OHS) after three week. The data on the body weight (BW), systolic blood pressure (SBP) and heart rate (HR) were recorded. Then the level of blood glucose, serum insulin and angiotensin II (AngII) were measured and the functional studies of the thoracic aorta was performed. RESULTS: The VS group exhibited higher SBP than the OHS group from the 6th week (113.7 +/- 4.2 mmHg vs. 104.0 +/- 5.8 mmHg, P < 0.01) and the VN group from the 7th week (117.6 +/- 6.3 mmHg vs. 109.6 +/- 4.6 mmHg, P < 0.01), while the SBP of the VN group was similar to those of the OHN group and the OHS group (P > 0.05). No significant differences in blood glucose, serum insulin and insulin sensitive index (ISI) were found among the four groups. The thoracic aorta segments of the VS group had higher contractive response to AngII (P < 0.01) and NE (P < 0.05) than the VN group, but the relaxations to acetylcholine (ACh) and nitroglycerine (NTG) showed no difference among the four groups (P > 0.05). CONCLUSION: The high-sucrose diet might elevate the blood pressure in young Wistar rats and the sympathetic system may play an important role in this process. |
| Effects of valsartan/hydrochlorothiazide and amlodipine on ambulatory blood pressure and plasma norepinephrine levels in high-risk hypertensive patients Malacco, E., S. Piazza, et al. (2004), Adv Ther 21(3): 149-61. Abstract: The efficacy and tolerability of the combination of valsartan and hydrochlorothiazide (HCTZ) were compared with that of amlodipine in reducing ambulatory blood pressure and plasma norepinephrine levels in patients with mild to moderate hypertension and at least 1 cardiovascular risk factor. At the end of a 2-week washout period, 92 outpatients with a sitting diastolic blood pressure > or =95 and <110 mm Hg, associated with at least 1 additional risk factor, were randomly assigned to receive either valsartan 160 mg and HCTZ 12.5 mg once daily (n=46) or amlodipine 10 mg alone once daily (n=46) for 12 weeks, according to a prospective, randomized, open-label, blinded end point, parallel-group design. At the end of the washout period and after 6 and 12 weeks of active treatment, 24-hour ambulatory blood pressure monitoring was performed, and clinical blood pressure and heart rate and plasma norepinephrine levels were assessed (by high-performance liquid chromatography). Both the valsartan/HCTZ combination and amlodipine had a demonstrable antihypertensive effect, but the combination showed an antihypertensive effect significantly greater than that of amlodipine, as demonstrated by the 24-hour (P<.001), daytime (P<.001), and nighttime ambulatory blood pressure values (P<.01) and by the clinical blood pressure values at trough, which were all significantly lower. Although the trough-to-peak ratios were similar in both groups, the smoothness indexes pertaining to both systolic and diastolic pressures were significantly higher (P<.05 and P<.001, respectively) in patients receiving valsartan/HCTZ, suggesting the combination produces a more homogeneous anti-hypertensive effect. A significant increase in plasma norepinephrine levels was associated with amlodipine (+9% at 6 weeks, +15% at 12 weeks) but not with the valsartan/HCTZ combination. The valsartan/HCTZ combination was better tolerated than amlodipine, which was associated with a higher frequency of ankle edema. These results indicate that the combination of valsartan 160 mg and HCTZ 12.5 mg provides more sustained and homogeneous control of blood pressure than does amlodipine 10 mg in high-risk hypertensive patients, without producing reflex sympathetic activation. |
| Effects of vitamin C on high blood pressure induced by salt in spontaneously hypertensive rats Nishikawa, Y., K. Tatsumi, et al. (2003), J Nutr Sci Vitaminol (Tokyo) 49(5): 301-9. Abstract: By breeding and feeding salt to spontaneously hypertensive rats (SHR) continuously over a long period (until 60 wk old), rats with systolic blood pressures (SBP) of over 270 mmHg were prepared. It was studied whether or not supplying large amounts of vitamin C (200 mg/rat/d) over this period might bring any beneficial effect to blood pressure. Moreover, physico-chemical studies were performed to measure the components and enzymes in the blood and urine at 53 and 60 wk-old, and biochemical studies on vitamin C were also carried out in this experiment. Male (14 rats: 7 wk-old, 100-105 g) and female (15 rats: 7 wk-old, 95-100 g) SHR were divided into three groups and bred continuously for 53 wk. The A group rats were given salt (2.5 g/100 g of diet), the B group rats were given salt and vitamin C (500 mg/100 mL of drinking water), and the C group rats were controls. The results showed almost the same tendencies between male and female rats. The body weights of the SHR in groups A and B were slightly lower than group C. The amount of food intake in groups A and B was almost the same as group C. The amount of water intake was, in the order from highest to lowest, group A, B and C. The SBP of group A rats exhibited the highest value among the three groups. The SBP of group B rats given vitamin C simultaneously with the salt resulted in a low blood pressure level close to that of the controls (group C). Furthermore, the DBP (diastolic blood pressure) also reflected the antihypertensive effect of vitamin C as well. The heartbeat of the rats was highest in group A, and was comparable to the value in the rats receiving vitamin C simultaneously with salt. For the tests on occult blood and protein in the urine, group A rats showed strong positive reactions, whereas the group B and C rats had decreased results for both tests. The organ weights of the liver, stomach, spleen, adrenal gland and kidneys per 100 g rat body weight were not different among the three groups. The values for the bilirubin content, and the enzyme activities of ALT and AST in the blood showed to be the highest in the male rats of group A. The values from the group B rats decreased near to the normal value like the control group. Vitamin C was found to decrease the blood pressure in SHR, and also to work effectively to protect liver and kidney functions even under the condition of very high blood pressure, as high as 250 mmHg. |
| Effects of vitamin C on high-density lipoprotein cholesterol and blood pressure Jacques, P. F. (1992), J Am Coll Nutr 11(2): 139-44. Abstract: Diet has been linked to cardiovascular disease risk by its influence on low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and blood pressure (BP). Recent evidence suggests that vitamin C may play a role in regulation of cholesterol and BP. The cross-sectional relationships of plasma ascorbic acid (PAA) with cholesterol and BP are described in three Boston area samples: 1) 249 males and 447 females (aged 60-100 years), 2) 100 Chinese-American males and 159 Chinese-American females (aged 60-96 years), and 3) 225 male and 192 female participants (aged 20-60 years) in a randomized field trial of vitamin C supplementation. Results indicate 3.7-9.5% higher levels of HDL-C, 4.1% lower levels of LDL-C, and 1.9-5.5% lower levels of BP with each 30 mumol/L increment in PAA. These relationships may be stronger at lower levels of PAA. |
| Effects on blood pressure, glucose, and lipid levels of a high-monounsaturated fat diet compared with a high-carbohydrate diet in NIDDM subjects Rasmussen, O. W., C. Thomsen, et al. (1993), Diabetes Care 16(12): 1565-71. Abstract: OBJECTIVE--To compare the influence on blood pressure, glucose, and lipid levels of a diet rich in monounsaturated fatty acids with an isocaloric, high-carbohydrate diet in 15 NIDDM subjects. RESEARCH DESIGN AND METHODS--A crossover design with diet interventions and wash-out periods of 3 wk was applied. The patients were randomly assigned to a 3-wk treatment with a high-carbohydrate diet containing 50% of energy as carbohydrate and 30% of energy as fat (10% of energy as monounsaturated fatty acids) or an isocaloric diet with 30% of energy as carbohydrate and 50% of energy as fat (30% of energy as monounsaturated fatty acids). On the last day of the two diets, 24-h ambulatory blood pressure was measured and day profiles of glucose, hormones, and lipids were performed to a test menu rich in carbohydrates. RESULTS--The diet rich in monounsaturated fat reduced daytime systolic (131 +/- 3 vs. 137 +/- 3 mmHg, P < 0.04) and 24-h systolic blood pressure (126 +/- 8 vs. 130 +/- 10 mmHg, P < 0.03) as well as daytime diastolic (78 +/- 2 vs. 84 +/- 2 mmHg, P < 0.02) and diurnal diastolic blood pressure (75 +/- 6 vs. 78 +/- 5 mmHg, P < 0.03) as compared with the high-carbohydrate diet. Evidence of lowered blood glucose levels on the high-monounsaturated diet compared with the high-carbohydrate diet were found with lower fasting blood glucose (6.1 +/- 0.3 vs. 6.8 +/- 0.5 mM, P < 0.05), lower average blood glucose levels (7.4 +/- 0.5 vs. 8.2 +/- 0.6 mM, P < 0.04), and peak blood glucose responses (9.9 +/- 0.6 vs. 11.3 +/- 0.7 mM, P < 0.02). The two diets had the same impact on lipid levels. CONCLUSIONS--A diet rich in monounsaturated fat has beneficial effects on blood pressure and glucose metabolism, whereas no adverse effects on lipid composition in NIDDM subjects is detected. |
| Efficacy of nonpharmacologic interventions in adults with high-normal blood pressure: results from phase 1 of the Trials of Hypertension Prevention. Trials of Hypertension Prevention Collaborative Research Group Whelton, P. K., S. K. Kumanyika, et al. (1997), Am J Clin Nutr 65(2 Suppl): 652S-660S. Abstract: Phase 1 of the Trials of Hypertension Prevention was conducted in 2182 adults, aged 35-54 y, with diastolic blood pressure of 80-89 mm Hg to test the feasibility and blood pressure-lowering effects of seven nonpharmacologic interventions (weight loss, sodium reduction, stress management, and supplementation with calcium, magnesium, potassium, and fish oil). At 6 and 18 mo, weight loss and sodium reduction were well-tolerated and produced significant declines in systolic and diastolic blood pressures (-2.9/-2.4 and -2.1/-1.2 mm Hg for weight loss and sodium reduction, respectively, at 18 mo). None of the other interventions lowered blood pressure significantly at either the 6- or 18-mo follow-up visits. These results suggest that both weight loss and sodium reduction provide an effective means to prevent hypertension. The long-term effects of both of these interventions are being tested in phase 2 of the trial. |
| Electrocardiographic changes in high blood pressure. Sova, J. (1950), Cas Lek Cesk 89(22): 623-9. |
| Elevated blood pressure and high sodium levels in the public drinking water. Preliminary results of a study of high school students Calabrese, E. J. and E. W. Tuthill (1977), Arch Environ Health 32(5): 200-2. Abstract: High school sophomores residing in a community with elevated levels of sodium in the drinking water (107 mg/1) exhibited a marked upward shift in blood pressure distribution patterns for systolic and diastolic blood pressures in both males and females as compared with a similar group in the control community (8 mg/1). The students group from the high sodium community appears to exhibit a blood pressure distribution characteristic of persons several years older. |
| Elevated blood pressure in spontaneously hypertensive rats consuming a high sucrose diet is associated with elevated angiotensin II and is reversed by vanadium Shi, S. J., H. G. Preuss, et al. (1997), J Hypertens 15(8): 857-62. Abstract: OBJECTIVE: To determine the changes in serum angiotensin II (Ang II) and endothelin-1 levels induced by vanadium treatment of sugar-fed rats in order to investigate the relationship between changes in blood pressure and Ang II and endothelin-1 levels. METHODS: Male spontaneously hypertensive rats (SHR) were fed starch (control), sucrose, and sucrose plus vanadium compounds at various concentrations. The systolic blood pressure of the rats was estimated by tail-cuff plethysmography. Serum Ang II and endothelin-1 levels were measured by radioimmunoassay. RESULTS: There were increases in systolic blood pressure (by 8%) and in serum Ang II (by 20%) in sucrose-fed SHR compared with control. In sucrose plus vanadium-fed SHR, the lowering of the systolic blood pressure (by 11-16% of the sucrose-fed value) was accompanied by a significant decrease in Ang II levels (by 25-60% of the sucrose-fed value) and an increase in endothelin-1 level (by 61-76% of the sucrose-fed value). CONCLUSION: That Ang II levels are elevated in sucrose-induced hypertension and decreased after vanadium therapy suggests that the renin-angiotensin system plays a role in the induction of hypertension in this model. On the other hand, the elevation of endothelin-1 levels associated with a decreased systolic blood pressure might be secondary to vanadium stimulation of endothelial cells. The data suggest that endothelin-1 is not involved in sugar-induced elevations of the blood pressure. |
| Elevated myocardial repolarization lability and reduced arterial baroreflex sensitivity in subjects with high-normal blood pressure Lantelme, P. (2005), J Hypertens 23(10): 1783-4. |
| Elevated nocturnal blood pressure assessed by ambulatory automatic monitoring during a stay at high altitude Barthelemy, J. C., J. R. Lacour, et al. (1995), Eur J Appl Physiol Occup Physiol 70(3): 258-62. Abstract: The aim of this study was to explore, in healthy children, the arterial blood pressure response to a 3-week stay at high altitude (4200 m). An auscultatory automatic ambulatory pressuremeter was used to avoid undue environmental influence on the measurement. The blood pressure was monitored three times in a group of ten boys, aged 10.5 (CI 0.9 years): at sea level (control values), at an altitude of 2100 m after at least 24 h of acclimatization and after at least 24 h at 4200 m altitude. Each period of monitoring extended over 24 h with 10-min intervals between successive measurements. Arterial blood pressure was evaluated separately for the night and day periods. Nocturnal recordings revealed an increase with altitude in systolic as well as in the diastolic blood pressure. Because of the technique used to gather data, this is thought to have represented an independent effect of altitude without interference from the medical environment or diurnal activity. |
| Elevated risk of high blood pressure: climate and the inverse housing law Mitchell, R., D. Blane, et al. (2002), Int J Epidemiol 31(4): 831-8. Abstract: BACKGROUND: In previous work the authors identified an 'inverse housing law' in Britain such that housing quality tends to be worse in areas of harsh climate than in areas where the climate is more benign. This study investigates whether an individual's risk of hypertension is associated with such a 'mismatch' between the quality of their housing and the climate to which they have been exposed. METHODS: Cross-sectional observational study based on Britain. Data came from the 5663 Health and Lifestyle Survey (HALS) participants for whom all relevant items were available. A two-stage study design was employed. First, the relationship between exposure to colder climate and housing quality was established. Second, the impact on risk of hypertension was determined for level of exposure to colder climate and housing quality. RESULTS: Analysis confirmed that amongst survey respondents, those with greater exposure to colder climate are more likely (1.32, 95% CI: 1.18-1.42) to live in poor quality housing than those with lower exposure to colder climate. This combination of higher exposure to colder climate plus residence in worse quality housing raises significantly the risk of diastolic hypertension (1.45, 95% CI: 1.18-1.77) and, more weakly, systolic hypertension (1.25, 95% CI: 1.01-1.53). CONCLUSIONS: There appears to be an 'inverse housing law' in Britain, whereby longer term residents of relatively cold areas are also more likely to live in worse quality housing and this combination of circumstances is associated with significantly higher risk of diastolic hypertension. The findings provide an example of how long term exposure to an adverse environment, which may stem from material disadvantage, can damage health. |
| Elevation of blood pressure induced by high-dose milnacipran Yoshida, K., H. Higuchi, et al. (2002), Hum Psychopharmacol 17(8): 431. |
| Emergency department detection and follow-up of high blood pressure: use and effectiveness of community health workers Bone, L. R., J. Mamon, et al. (1989), Am J Emerg Med 7(1): 16-20. Abstract: This study introduced trained paraprofessionals, community health workers (CHWs), into the emergency department (ED) to supplement providers' routine efforts in high blood pressure (HBP) detection, treatment, and follow-up among high-risk black men. In a demonstration project over a 2-year period, CHWs provided (1) BP and pulse measurements, and educational counseling regarding HBP and cardiovascular risk factors; (2) telephone preappointment reminders to improve ED follow-up visit rates; and (3) recontact of patients failing to show for their ED follow-up visits to improve return rates even after missed BP appointments. Results of preappointment reminders by CHWs showed a 19% improvement in appointment keeping (P less than.001). With a sample of patients who had failed to return for a follow-up visit, CHW contact was also effective, showing an overall improvement rate of 7% (P less than.001). The results reported support the idea that individuals from the community, trained as paraprofessionals, can improve appointment keeping as well as be useful in assisting in screening and counseling for chronic conditions within the ED. These CHWs are seen as having the additional advantage of enhancing the integration of the ED, the community, and continuing care sites. The approaches used in this study should be applicable and may serve as a model for the approach to other chronic conditions experienced in urban high-risk communities. |
| Emergency treatment of high blood pressure with oral atenolol Bannan, L. T. and D. G. Beevers (1981), Br Med J (Clin Res Ed) 282(6278): 1757-8. |
| Emotional problems of high blood pressure Weiss, E., B. Jaffe, et al. (1950), Am J Psychiatry 107(4): 264-70. |
| Employment status and high blood pressure in women: variations by time and by sociodemographic characteristics Rose, K. M., B. Newman, et al. (1997), Ann Epidemiol 7(2): 107-14. Abstract: PURPOSE: The association between employment status and high blood pressure in women was examined at two time periods to determine if associations between employment status and high blood pressure varied by time period or by age, race, education, marital status, or parental status. METHODS: Women participants from the National Health Examination Survey (1960) and the Second National Health and Nutrition Survey (1976-1980) between the ages of 25 and 64 and currently employed or keeping house were included. Logistic regression analysis was used to examine the cross-sectional association between employment status and high blood pressure in each survey, taking into account potential effect modifiers and covariates. RESULTS: In 1960 employment was associated with a slight, but not statistically significant, elevation in odds of high blood pressure. In 1976-1980, it was associated with a modest but significant reduction in odds of high blood pressure. Variations in associations occurred by marital status (protective associations were limited to unmarried women) and race (associations were of stronger magnitude among African-American women). CONCLUSIONS: The employment status-high blood pressure relationship shifted across surveys. Changes in the composition of the employed and nonemployed groups account for at least part of the varying relationships. |
| Endothelial dysfunction in resistance arteries is related to high blood pressure and circulating low density lipoproteins in previously treated hypertension Olsen, M. H., K. Wachtell, et al. (2001), Am J Hypertens 14(9 Pt 1): 861-7. Abstract: BACKGROUND: Peripheral endothelial dysfunction has been demonstrated in hypertension. However, its relationship to blood pressure (BP) load, vascular structure, and metabolic disturbances in patients with long-standing, previously treated hypertension is unclear. METHODS: A total of 41 patients with stage I to III essential hypertension and electrocardiographic left ventricular hypertrophy were studied. After 2 to 3 weeks of placebo treatment we measured nitroprusside-induced relaxation (NIR), acetylcholine-induced relaxation (AIR), and media:lumen ratio in isolated, subcutaneous resistance arteries by myography, as well as 24-h ambulatory BP, and serum lipids. RESULTS: Maximal AIR correlated negatively with median 24-h diastolic BP (r=-0.42, P=.01), and sensitivity to AIR correlated negatively with serum low density lipoprotein (LDL) (r =-0.36, P <.05). In multiple regression analyses, sensitivity to AIR correlated negatively with serum LDL (beta=-0.33) independently of maximal NIR (beta=0.41) (adjusted R2 =0.26, P <.01). Maximal acetylcholine-induced relaxation correlated negatively with median 24-h diastolic BP (beta=-0.38) independently of maximal NIR (beta=0.45) (adjusted R2= 0.32, P <.001). Acetylcholine-induced relaxation was not significantly related to diabetes or to media:lumen ratio (r = -0.26, NS). CONCLUSIONS: High diastolic BP and high serum LDL were associated with impaired maximal AIR and reduced sensitivity to AIR, respectively, independently of smooth muscle cell responsiveness to nitroprusside. This indicated decreasing endothelial function in small resistance arteries with increasing BP and increasing LDL in hypertension. Endothelial function was not significantly related to vascular structure of the resistance arteries or to diabetes in these patients with long-standing hypertension. |
| Endothelial-independent prevention of high blood pressure in L-NAME-treated rats by angiotensin II type I receptor antisense gene therapy Reaves, P. Y., C. R. Beck, et al. (2003), Exp Physiol 88(4): 467-73. Abstract: It has previously been established that a single systemic administration of retroviral vector containing angiotensin II type I receptor antisense (AT(1)R-AS) in the neonatal spontaneously hypertensive rat (SHR) prevents development of hypertension, and in addition cardiac hypertrophy and endothelial dysfunction. However, these studies could not determine whether the effects of AT(1)R-AS on high blood pressure (BP) and endothelial function were independent. Angiotensin receptor blockers have been shown to reduce BP in the L-NAME (N (omega)-nitro-L-arginine methyl ester hydrochloride)-induced rat model of hypertension. Our objective in the present study was to use the L-NAME model of hypertension to determine whether AT(1)R-AS treatment would lower high BP and attenuate cardiac hypertrophy under conditions of permanent endothelial damage. A single bolus of LNSV-AT(1)R-AS viral particles in neonatal Wistar-Kyoto (WKY) rats was without affect on basal BP. Efficacy of the transgene incorporation was assessed by observing a significant reduction in angiotensin-induced dipsogenic response in the AT(1)R-AS-treated animals. Introduction of L-NAME in the drinking water for 10 weeks resulted in the establishment of hypertension only in the WKY rats treated with vector alone. These hypertensive (BP, 179 +/- 4 mmHg) animals showed a 17 % increase in heart weight/body weight ratio and a 60 % reduction in ACh-induced vasorelaxation in phenylephrine-preconstricted arteries. The L-NAME-induced high BP and cardiac hypertrophy were attenuated in rats expressing AT(1)R-AS. However, endothelial dysfunction could not be prevented with the antisense therapy. These observations demonstrate that attenuation of endothelial dysfunction is not a prerequisite for the antihypertensive effects of AT(1)R-AS treatment. |
| Endothelin receptor A blockade reduces proteinuria and vascular hypertrophy in spontaneously hypertensive rats on high-salt diet in a blood-pressure-independent manner Trenkner, J., F. Priem, et al. (2002), Clin Sci (Lond) 103 Suppl 48: 385S-388S. Abstract: The renal endothelin (ET) system is involved in the pathogenesis of kidney fibrosis as well as blood pressure control by regulating tubular sodium excretion. Long-term effects of ETA receptor blockade on blood pressure and kidney function in spontaneously hypertensive rats (SHRs) on a high-salt diet are unknown. We treated SHRs on a 6% (w/v) NaCl sodium diet (SHR-S) for 48 weeks with the ETA antagonist LU 135252 (whose selectivity for ETA is 150 times greater than for ETB) with 10, 30 and 100 mg x kg(-1) x day(-1) or placebo. The ETA antagonist had at no time-point any effect on blood pressure. Glomerular filtration rate was normal in SHR-S and not altered by LU 135252. However, urinary albumin excretion was markedly reduced by the ETA antagonist (SHR-S, 145+/-50 mg/day; SHR-S+10 mg x kg(-1) x day(-1) LU 135252, 33+/-11 mg/day, P<0.05 versus SHR-S; SHR-S+30 mg x kg(-1) x day(-1) LU 135252, 55+/-16 mg/day and SHR-S+100 mg x kg(-1) x day(-1) LU 135252, 32+/-11 mg/day, P<0.05 versus SHR-S at both concentrations). Total urinary protein excretion was likewise significantly reduced by treatment with 10 mg.kg(-1).day(-1) LU 135252 (SHR-S, 0.25+/-0.06 g/day; SHR-S+10 mg x kg(-1) x day(-1) LU 135252, 0.089+/-0.01 g/day, P<0.05 versus SHR-S). The higher dosages of LU 135252 showed only a trend towards reduction of total urinary protein excretion. Computer-aided image analysis after haematoxylin/eosin and periodic acid-Schiff staining revealed that treatment with 10 mg x kg(-1) x day(-1) LU 135252 significantly reduces the media/lumen ratio of intrarenal arteries. Higher dosages of LU 135252 were less effective. Renal matrix protein synthesis in SHR-S was not altered by LU 135252. In conclusion, the renal ET system contributes in a blood-pressure-independent manner to the regulation of urinary protein excretion and renal vascular hypertrophy in SHR-S. Lower doses of the ETA antagonist were more effective, indicating that a potential additional blockade of the ETB receptor using higher doses of LU 135252 seems to oppose the beneficial effects of a sole ETA blockade. Urinary protein excretion is an independent risk factor of chronic renal failure, thus ETA antagonists might be a therapeutic tool to prevent proteinuria-induced chronic renal failure. |
| Endothelium and high blood pressure Noll, G., M. Tschudi, et al. (1997), Int J Microcirc Clin Exp 17(5): 273-9. Abstract: Due to its strategic anatomical position, the endothelium is constantly exposed to the different risk factors for atherosclerosis. During the last decade it has become clear that hypertension profoundly affects endothelial function. Depending on the form of hypertension, endothelium-dependent relaxation is impaired in most vascular beds. In spontaneous hypertension, the production of nitric oxide, which in endothelial cells is formed from L-arginine via the constitutively expressed enzyme endothelial nitric oxide synthase, represents the main mediator of endothelium-dependent vasodilation and seems to be enhanced. On the other hand, the release of endothelium-dependent contracting factors such as prostaglandin H2 and thromboxane A2 have been demonstrated in this model of hypertension. Similar results have been obtained in the forearm circulation of patients with essential hypertension. In contrast, in models of salt-sensitive hypertension no release of vasoconstrictor prostanoids can be found indicating a decreased production of nitric oxide. Thus, in spontaneous hypertension an increased production of nitric oxide seems to occur, which is ineffective due to either the simultaneous release of endothelium-dependent vasoconstrictors and/or inactivation of nitric oxide, or due to anatomical changes such as hypertension-induced intimal thickness which inhibits its action on vascular smooth muscle cells. In summary, in hypertension, endothelium-dependent vasodilation is blunted and the endothelial L-arginine nitric oxide pathway is altered. These changes seem to represent a consequence rather than a cause of hypertension. |
| Enhanced blood pressure responses to loud noise in offspring of monkeys with high blood pressure Kirby, D. A., J. A. Herd, et al. (1984), Physiol Behav 32(5): 779-83. Abstract: Sixteen unanesthetized immature Macaca fascicularis monkeys, 18-43 months of age, were tested for mean arterial blood pressure (MBP) and heart rate (HR) responses to 30 minutes of continuous broadband noise (95 dB). Eight animals (OH group) were offspring of monkeys with high blood pressure (parents' MBP = 115.5 +/- 1.0 (SEM) mmHg), and eight (OC group) were offspring of control animals with normal blood pressure (parents' MBP = 96.6 +/- 1.7 mmHg). Resting MBP during a 17-24 hour period prior to the experiment in the OH group was 100.6 +/- 1.9 mmHg, significantly higher (p less than 0.05) than the MBP of the OC group (94.3 +/- 2.2 mmHg.) Immediately prior to noise exposure, MBP in the OH group was stable for 30 minutes, at 104 +/- 3 mmHg. During noise exposure, MBP increased significantly to 108 +/- 4 mmHg. In the OC group, MBP during the 30 min baseline interval was 95 +/- 2 mmHg, and during noise exposure was not significantly changed at 94 +/- 3 mmHg. Heart rate decreased significantly during noise in the OC group and did not change in the OH group. The results indicate that the offspring of monkeys with high blood pressure had higher resting MBP than control animals and showed significant MBP increases in response to loud noise. Control animals showed no change in MBP and decreases in HR in response to noise. |
| Enhanced sensitivity to salt-induced high blood pressure in diabetes mellitus Orie, N. N., C. P. Aloamaka, et al. (1994), Res Exp Med (Berl) 194(3): 197-202. Abstract: Salt-induced high blood pressure in diabetic rats was compared with that in non-diabetic (control) rats. Before the rats had eaten the high-salt diet, the diabetic group exhibited significantly greater pressor response to noradrenaline (100 ng/100 g body weight) than the controls (P < 0.05). When the rats were given a high-salt diet, a significant increase in blood pressure was recorded 4 weeks earlier in the diabetic than in the control group (P < 0.05); this increase occurred after 2 weeks in the diabetic group, but after 6 weeks of high-salt diet in the controls. The enhanced state of vascular reactivity in the diabetic rats was probably responsible for their enhanced sensitivity to salt-induced high blood pressure. |
| Enhancement of the pulmonary vasoconstriction reaction to alveolar hypoxia in systemic high blood pressure Guazzi, M. D., M. Berti, et al. (1991), Clin Sci (Lond) 80(4): 403. |
| Enovid-induced exacerbation of high blood pressure in stroke-prone rats (SHR) Wexler, B. C. (1981), Stroke 12(1): 101-5. Abstract: Male and female, normotensive Wistar:Kyoto rats, spontaneously hypertensive rats (SHR), and Stroke-prone SHR (SHR/SP) with severe hypertension were treated with a contraceptive drug (Enovid) from the time of weaning until they became 180 days old. Although the Envoid-treated SHR and SHR/SP had exacerbations of their high blood pressure, none of the animals developed renal or cerebral damage. Chronic treatment with Enovid caused testicular and ovarian atrophy and a significant increase in circulating corticosterone. It is suggested that the potentially deleterious effects, e.g., stroke, hypertension, hyperglycemia, hyperlipidemia, etc., of chronic treatment with contraceptive drugs is largely determined by pre-existing genetically endowed proneness or resistance. |
| Environmental influences as risk factors - their recognition as a first step in high blood pressure prevention Bock, K. D. (1980), Verh Dtsch Ges Inn Med 86: 303-10. |
| Epidemiologic aspects of high blood pressure in the elderly Blumenstock, J. and C. Leibing (1983), Offentl Gesundheitswes 45(7): 327-32. |
| Epidemiological observations on high blood-pressure without evident cause Morrison, S. L. and J. N. Morris (1959), Lancet 2: 864-70. |
| Epidemiology of high blood pressure Ripka, O. (1968), Med Klin 63(3): 89-93. |
| Epidemiology of high blood pressure Whelton, P. K. and M. J. Klag (1989), Clin Geriatr Med 5(4): 639-55. Abstract: Experience in isolated "unacculturated" societies suggests that age-related changes in blood pressure are not a biologic necessity. In the developed world, however, blood pressure tends to rise progressively with increasing age, and hypertension in the elderly is an extremely common finding. Blood pressure is positively related to the risk of subsequent cardiovascular disease in elderly persons, as in younger persons, in a graded continuous fashion. Based on prevalence and risk considerations, high blood pressure in the elderly population is one of the most pressing individual and public health problems of this century. |