首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 33 毫秒
1.
Blood pressure (BP) changes during the menstrual cycle (MC) have not been studied in hypertensive women in relationship to changes in sex hormone levels and plasma renin activity (PRA). We therefore carried out 24 h ambulatory BP recordings and hormonal measurements in 34 hypertensive and 27 matched normotensive women during the follicular ovulatory and luteal phases of the menstrual cycle. Plasma renin activity was similar in the two groups and rose significantly during the luteal phase only in the hypertensives (P < .01). There were no differences in plasma estradiol or progesterone between the normotensives and hypertensives, but testosterone was higher in the hypertensives during the ovulatory (P < .01) and luteal (P < .001) phases. Blood pressure did not change in the normotensives throughout the cycle, but it increased in the hypertensives during ovulation (P < .01). When patients were divided according to mean menstrual cycle PRA, only those with relatively low PRA (< 2 ng/mL/h) had a significant BP rise during ovulation and it primarily occurred at night (P < .05). The results demonstrate that premenopausal hypertensive women have increased testosterone during ovulation and increased testosterone and PRA during the luteal phase of the cycle. Like normotensives, hypertensives with relatively high PRA exhibit no change in BP during the cycle, whereas those with relatively low PRA have a nighttime increase in BP during ovulation.  相似文献   

2.
Compared cardiovascular reactivity to video game and mental arithmetic stressors among 3 groups of men (aged 21–63 yrs): (a) 11 aerobically trained mild hypertensives, (b) 7 untrained mild hypertensives, and (c) 9 untrained normotensives. Blood pressure (BP) reactivity of normotensives during the video game was generally similar to that of trained hypertensives but smaller than that of untrained hypertensives. There were no group differences in reactivity during mental arithmetic. Results indicate that aerobic training, which has been found to reduce resting BP in mild hypertensives, may also exert a favorable impact in reducing cardiovascular reactivity of hypertensives during some stressful situations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

3.
The aim of this study was to elucidate further the precise nature of the so-called "white coat" (WC) effect. We enrolled 88 hypertensive (46 men, 42 women) and 18 normotensive (4 men, 14 women) subjects in whom beat-to-beat blood pressure (BP) and heart rate (HR) were measured with a Finapres device at rest (R period) and during conventional BP measurement (WC period). The WC effect was defined as WC period minus R period values of Finapres systolic BP. Using the same method, we also measured the BP and HR variations induced by mental stress (MS period) and by assuming the standing position (S period). Variability was estimated in the frequency domain for BP (BPV) and HR (HRV) and gave indices of the autonomic nervous system. Pulse wave velocity was taken as an index of arterial distensibility. In hypertensive subjects, the WC effect was significantly and positively correlated with the BP response to stress (0.51, P<.0001) and standing (0.63, P<.0001). An increased BPV was observed in the low-frequency band (0 to 0.150 Hz) during WC, MS, and S periods. In normotensive subjects, the WC effect was very slight and not correlated with the responses to stress and standing. In this group, the WC period was not accompanied with an increased BPV, unlike the stress and standing periods. HRV was similar in normotensives and in hypertensives: decreased, unchanged, and increased during MS, S, and WC periods, respectively. The PWV was significantly increased in the hypertensives relative to the normotensives, even in the quartile of those with the lowest BP (on average similar to that of the normotensives). This work shows that the WC effect is associated with an enhanced BP response to standing and mental stress; these three situations are characterized by an increased BPV in the low frequencies, suggesting a similar modification of the sympathovagal balance. The WC effect may entail an increased risk because it is associated with impaired arterial distensibility.  相似文献   

4.
The association between perceived symptoms and absenteeism was examined in five groups of employed adults: normotensives, unaware hypertensives, aware and untreated hypertensives, aware and treated hypertensives, and falsely aware normotensives. Aware hypertensives (untreated and treated) and falsely aware normotensives had a higher average of perceived symptoms than normotensives, whereas unaware hypertensives had lower. The absenteeism rate across the groups showed a similar pattern. A significant interaction of perceived symptoms by study group on absenteeism was uncovered. Hypertensives and falsely aware normotensives who reported a low level of symptoms were not absent more than their normotensive counterparts. However, aware hypertensives and falsely aware normotensives who perceived a high symptoms level showed higher absenteeism than unaware hypertensives and normotensives with a similar level. This suggests that aware hypertensives have a greater tendency than both normotensives and unaware hypertensives to equate their symptoms with ill health and to act accordingly. Special attention should be directed to aware hypertensives who perceive a threat to their health.  相似文献   

5.
BACKGROUND: The prevalence of left ventricular hypertrophy (LVH) is higher in elderly patients with hypertension than in normotensive patients. The factors relationed herewith are not well known. The first purpose was to analyse the relationship between the levels of blood pressure (BP) recorded by ambulatory blood pressure monitoring (ABPM) and the left ventricular mass index (LVMI) in a group of untreated patients older than 55 years with essential hypertension. Our second purpose was to observe the relationship between the concentration of several circulating hormones and the left ventricular mass index. SUBJECTS AND METHODS: The study included 31 untreated patients with mild to moderate essential hypertension and 37 healthy normotensives. Both groups were of similar age, sex and body mass index. We determined for both groups the casual arterial pressure (CAP), ambulatory BP monitoring (ABPM) throughout 24 h, daytime (07.00-23.00 h), nighttime (23.00-07.00 h), left ventricular mass index (LVMI) (following Devereux's formula) and circulating levels of endothelin-1, aldosterone, renine, free adrenaline and noradrenaline. RESULTS: The ILVM in hypertensive patients was 139.6 +/- 35.9 g/m2 and in 124.0 +/- 31.8 g/m2 in normotensive (p < 0.05). The percentage of patients with LVH was 63 and 43%, respectively (p < 0.05). The LVMI in hypertensive patients was correlated with the diastolic CAP (97 +/- 7 mmHg) (r = 0.41; p < 0.05), unlike with the systolic CAP (164 +/- 18 mmHg). The ILVM in normotense patients was not associated neither with the systolic CAP (126 +/- 10 mmHg) nor with the diastolic (79 +/- 6 mmHg). In hypertensive patients we found a slight association between the LVMI and the systolic ABPM (130 +/- 14 mmHg) during nighttime (r = 0.41; p < 0.05). The rest of average ambulatory BP and the hormonal values at study did not show a correlation with the LVMI in both groups. CONCLUSIONS: A slight correlation exists between BP (casual and determined with ambulatory blood pressure monitoring throughout 24 hours) and the left ventricular mass index in mild to moderate untrated hypertensive patients older than 55 years. We did not observe correlations between the circulating levels of endothelin-1, renin, aldosterone, free adrenaline and noradrenaline and the left ventricular mass. The average ventricular mass and the number of subjects with ventricular hypertrophy was significantly increased in hypertensives than in normotensives.  相似文献   

6.
OBJECTIVE: To assess the effects of angiotensin II on intracellular free Mg2+ and Ca2+ concentrations in platelets from normotensive and hypertensive subjects. DESIGN AND METHODS: Seventeen normotensive, 25 untreated hypertensive and 18 treated hypertensive patients were studied. Intracellular Mg2+ concentrations were measured with the fluorescent dye mag-fura-2-acetyoxymethylester (AM) and intracellular Ca2+ concentrations with the fluorescent dye fura-2AM under basal conditions and after stimulation by angiotensin II, saralasin (angiotensin II antagonist), arginine vasopressin and endothelin-1. The effects of increased extracellular Mg2+ concentrations on intracellular Mg2+ and Ca2+ concentrations were also determined. RESULTS: The intracellular basal Ca2+ concentration was significantly higher in the untreated hypertensives compared with the normotensives and treated hypertensive subjects (150 +/- 14 nmol/l versus 120 +/- 17 nmol/l for normotensives and 124 +/- 8 nmol/l for treated hypertensives). The basal intracellular Mg2+ concentration was significantly lower in the untreated hypertensive compared to the normotensive and treated hypertensive groups (0.37 +/- 0.08 mumol/l versus 0.58 +/- 0.09 mumol/l for normotensives and 0.52 +/- 0.11 mumol/l for treated hypertensives). In the hypertensive groups, inverse correlations were found between intracellular Ca2+ and intracellular Mg2+ concentrations (r = -0.44, P < 0.05) and between intracellular Mg2+ and diastolic blood pressure (r = -0.35, P < 0.05), while a positive correlation was found between intracellular Ca2+ and systolic blood pressure (r = 0.41, P < 0.05). Exposure of the platelets to 1 nmol/l angiotensin II significantly increased intracellular Ca2+ and significantly decreased intracellular Mg2+ concentrations in all three groups. The angiotensin II-evoked effect on intracellular Ca2+ was exaggerated in the untreated hypertensives and blunted in the treated patients (basal versus stimulated: 150 +/- 14 versus 217 +/- 20 nmol/l in untreated hypertensives; 124 +/- 8 versus 140 +/- 10 nmol/l in treated hypertensives). Saralasin (0.1 mumol/l) abolished the effects of angiotensin. Arginine vasopressin (1 mumol/l) increased the intracellular Ca2+ concentration, whereas endothelin-1 (1 nmol/l) had no significant effect on either intracellular Ca2+ or intracellular Mg2+. Increasing extracellular Mg2+ concentrations led to significant reductions in intracellular Ca2+ concentrations in all groups and a significant elevation of the intracellular Mg2+ concentration in the untreated hypertensive patients only. CONCLUSIONS: These data demonstrate a relationship between angiotensin II and intracellular magnesium and calcium. In hypertension, angiotensin II-stimulated calcium responses may be related to simultaneously decreased intracellular magnesium concentrations.  相似文献   

7.
DESIGN AND METHODS: Local elastic properties of the descending aorta at different levels were evaluated by means of intravascular ultrasound images and pressure measurements. For this purpose, 30 normotensive patients and 30 age-matched medically treated patients with essential hypertension, all undergoing diagnostic cardiac catheterization, were studied. RESULTS: Hypertension was well controlled in the essential hypertensives (137.1 +/- 6.79/74.5 +/- 2.65 mmHg). Systolic but not diastolic blood pressure in the hypertensive patients was significantly different from that of the normotensives (118.8 +/- 4.38/69.7 +/- 1.65 mmHg). The continuous loss of volume compliance with increasing distance from the heart was significantly higher in the hypertensives than in the normotensive patients [normotensives (1.45 +/- 0.19) x 10(-10) m5/N at the thoracic aorta, (0.08 +/- 0.05) x 10(-10) m5/N at the external iliac artery; hypertensives (0.81 +/- 0.09) x 10(-10) and (0.05 +/- 0.01) x 10(-10) m5/N at the corresponding sites]. Similarly, the hypertensives had an elevated elastic modulus proximal to the aortic bifurcation compared with the normotensives (244.47 +/- 44.06 versus 108.10 +/- 17.76 m/s, respectively). The decrease in buffering function of the vessel at this site is presumably caused by a turbulent flow pattern. Compared with the normotensives, the treated hypertensives had a significantly higher elastic modulus at each site where this was measured, whereas volume compliance and sectional compliance were lower. CONCLUSION: The differences in elastic modulus and compliance between hypertensive and normotensive patients seem disproportionate to the difference in systolic blood pressure (within the normal range in both the treated hypertensives and the normotensives). Therefore, normalization of high blood pressure by long-term antihypertensive treatment may not fully reverse changes, caused by arterial hypertension, in the viscoelastic properties of the arterial wall.  相似文献   

8.
Black hypertensive persons have been observed to have a greater degree of left ventricular hypertrophy than white hypertensives. However, previous studies have matched groups for blood pressure (BP) measured in the clinic, and it has been demonstrated that black hypertensives have an attenuated nocturnal BP dip. Clinic BPs may thus underestimate mean 24-hour BP in this group. To investigate whether the differences in left ventricular hypertrophy can be accounted for by the greater mean 24-hour BP in black hypertensives, 92 previously untreated hypertensives were studied with 24-hour ambulatory BP monitoring and echocardiography. The 46 black hypertensives (24 men and 22 women) were matched with the 46 white hypertensives for age, gender, and mean 24-hour BP. Despite similar mean 24-hour BPs (blacks, 142/93 mm Hg; whites, 145/92 mm Hg; P=.53/.66), the black group had a smaller mean nocturnal dip than the white group (blacks, 8/8 mm Hg; whites, 16/13 mm Hg; P<.01). In addition, mean left ventricular mass index (LVMI) was greater (blacks, 130 g/m2; whites, 107 g/m2; P<.001). Mean 24-hour systolic BP was significantly related to LVMI in both groups (blacks, r=.45, P<.01; whites, r=.56, P<.01). However, systolic BP dip correlated inversely with LVMI only in the black group (blacks, r=-.30, P<.04; whites, r=.05, P=.76). In a multiple regression model, LVMI was independently related to both mean daytime BP and mean nocturnal BP dip in black subjects but only to mean daytime BP in white subjects. In conclusion, the increased left ventricular hypertrophy observed in black hypertensives compared with white hypertensives is not accounted for by differences in mean 24-hour BP. However, LVMI in black hypertensives appears to be more dependent on nocturnal BP than that in white hypertensives; this, coupled with the attenuated BP dip in black hypertensives, suggests that the BP profile rather than 24-hour BP may be important in determining the differences in left ventricular hypertrophy.  相似文献   

9.
This study was performed to compare metabolic and endocrine characteristics of untreated hypertensive patients and normal controls. Measurements were made in age-matched, body mass index (BMI) matched, normotensive patients with (n = 40; age = 53; BMI = 28) and without (n = 39; age = 54; BMI = 27) a family history of hypertension and hypertensive patients with (n = 38; age = 53; BMI = 28) and without (n = 25; age = 54; BMI = 29) a family history of hypertension. Norepinephrine, renin activity, and total cholesterol blood concentrations were similar in normotensive patients with a positive family history of hypertension and in hypertensive patients with or without a family history. Similarly, there were no differences in plasma insulin concentrations or insulin/glucose ratios between the normotensive patients with a family history of hypertension and hypertensive patients with or without a family history. But in all three groups the values were significantly greater (at least p < 0.05 for each) than in the normotensive patients without a family history. Increases in systolic blood pressure during treadmill testing were 51 +/- 4 mm Hg in the normotensive patients with a family history, 50 +/- 3 mm Hg in hypertensives with a family history, and 45 +/- 5 mm Hg in hypertensives without a family history; these changes were all less (p < 0.05 for each) than in normotensives without a family history (65 +/- 3 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

10.
OBJECTIVE: Angiotensin II type 1 receptor-mediated constrictor effects may be modulated by hypertension-related vascular changes, changes in receptor function and in neurohumoral activity. DESIGN: The forearm blood flow (FBF) effects of angiotensin II, methoxamine, and losartan were investigated in essential hypertensive patients. Minimal forearm vascular resistance was measured to determine structural vascular changes. METHODS: Seven hypertensive patients were selected, and seven matched normotensives. Angiotensin II (0.01-10 ng/kg per min) was infused during predilatation by sodium nitroprusside (6.1 +/- 0.6 ng/kg per min) before and during losartan infusion (0.3-3 microg/kg per min). Methoxamine (0.2-2 microg/kg per min) was co-infused with the nitric oxide synthase inhibitor NG-monomethyl-L-arginine. FBF, measured by venous occlusion plethysmography, was expressed as the change in FBF ratio (FBFinfused arm/FBFnon-infused arm). RESULTS: Baseline FBF (infused arm) was increased by sodium nitroprusside from 2.56 +/- 0.80 to 5.46 +/- 0.92 (P<0.05) and from 2.66 +/- 0.25 to 5.42 +/- 0.40 ml/100 ml per min (P<0.05) in the hypertensive and normotensive group, respectively. Baseline forearm vascular resistance (FVR) was higher in the hypertensive than in the normotensive group [51 +/- 8 versus 33 +/- 3 mmHg/ (ml/100 ml per min); P<0.05]. Angiotensin II caused a maximal change in FBF ratio (Emax) by -70 +/- 3 and -72 +/- 6% in the hypertensive and normotensive group, respectively (NS). Tachyphylaxis did not occur. Infusions of losartan at 0.3, 1 and 3 microg/kg per min reduced the Emax values from -70 +/- 3 to -50 +/- 5, -45 +/- 5 and -15 +/- 2%, respectively, in the hypertensive group, and from -72 +/- 6 to -62 +/- 4, -45 +/- 2 and -32 +/- 2%, respectively, in the normotensive group (NS). Infusion of methoxamine significantly reduced the FBF ratio by -58 +/- 6 and -69 +/- 5% in the hypertensive and normotensive groups, respectively (NS). Minimal FVR, after forearm ischemia, was the same in hypertensives and normotensives, namely 3.2 +/- 0.7 and 3.2 +/- 0.4 mmHg/(ml per 100 ml per min), respectively (NS). CONCLUSIONS: Angiotensin II type 1- and alpha1-mediated vascular effects were unchanged by essential hypertension. Baseline FVR was greater in the hypertensives than in the normotensives, while minimal FVR was the same. These results indicate that the forearm vascular bed of the patient group studied does not show important structural and renin-angiotensin system-related functional changes as a result of hypertension.  相似文献   

11.
14 medicated hypertensive, 15 nonmedicated mild hypertensive, 39 normotensive, and 13 hypotensive adults participated in a 1–2 hr laboratory experiment that assessed each S's symptoms, moods, and estimates of systolic blood pressure (SBP) relative to actual SBP levels. Several self-reports and autonomic measures were collected during and after each of 22 tasks. Within-S correlations indicated that all Ss could estimate SBP at levels greater than chance. Further, 68% of the Ss evidenced at least 1 significant symptom–SBP correlation. Although medicated hypertensives believed they could estimate their BP more accurately than other groups, they were actually no more accurate than the other Ss. They also evidenced far fewer empirically derived symptom–SBP and emotion–SBP correlations than any other group. Overall, blood pressure (BP) beliefs were largely inaccurate. If these erroneous beliefs can be eliminated, Ss may be able to estimate BP fluctuations more accurately. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

12.
A twenty-four-hour blood pressure (BP) monitoring was performed in 20 normotensive and 20 hypertensive subjects, matched by sex and age. Blood pressure and heart rate (HR) variability were evaluated both as absolute and percent standard deviation. In agreement with the literature no significant difference in HR and BP variability was observed between the two groups. The linear regression between HR and BP values was evaluated in both groups. The authors observed a significant difference in the relationship between these two cardiovascular variables between the two groups. In the hypertensive group the cardiovascular control of HR and BP showed a different relationship than in normotensive subjects, suggesting a different neurovegetative modulation.  相似文献   

13.
OBJECTIVE: The aim of this study was to investigate the relationships between levels of natriuretic peptides and adrenomedullin and 24 h blood pressure levels in elderly hypertensives. DESIGN AND METHODS: We performed both 24 h ambulatory blood pressure monitoring and measurement of plasma levels of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and adrenomedullin in 118 asymptomatic hypertensive elderly (> 60 years old) patients. We classified the subjects into groups with isolated clinic hypertension (n = 40) and sustained hypertension (n = 78). We also measured the levels of these peptides in 37 elderly normotensive subjects. RESULTS: Plasma ANP and BNP levels were slightly increased in patients with isolated clinic hypertension compared with elderly normotensives. Among the hypertensives, plasma ANP and BNP levels were more closely related to 24 h blood pressure levels than to office blood pressure levels. Sustained hypertensives showed significantly increased plasma levels of ANP and BNP compared with isolated clinic hypertensives, while adrenomedullin levels were similar in the two groups. Elderly hypertensives with left ventricular hypertrophy detected by electrocardiography had significantly higher levels of ANP and BNP, and higher BNP/ANP ratios than those without left ventricular hypertrophy, while there was no significant difference in adrenomedullin levels between the two groups. CONCLUSIONS: Our results suggest that measurements of ANP and BNP may be useful in detecting left ventricular hypertrophy and in differentiating isolated clinic hypertension from sustained hypertension in elderly hypertensive patients.  相似文献   

14.
BACKGROUND: Patients with essential hypertension have impaired endothelial NO activity, but the mechanism underlying this abnormality is unknown. METHODS AND RESULTS: To investigate whether the endothelial dysfunction of hypertensive patients is related to a selective defect in NO synthesis, we studied the forearm blood flow responses to intra-arterial infusion of acetylcholine (7.5 to 30 microg/min), an endothelial agonist linked to NO synthase through the Ca2+ signaling pathway, and isoproterenol (50 to 200 ng/min), a beta-adrenoceptor agonist that stimulates NO production by increasing intracellular cAMP, in 12 normotensive subjects and 12 hypertensive patients. The infusion of isoproterenol was repeated during the concurrent blockade of NO synthesis by NG-monomethyl-L-arginine (L-NMMA; 4 micromol/min). The vasodilator response to acetylcholine was significantly reduced in hypertensives compared with normotensives (maximum blood flow: 10.4+/-4.6 versus 14.4+/-3.7 mL x min[-1] x dL[-1]; P=.008). However, the vasodilator effect of isoproterenol was similar in normotensives and hypertensives (maximum blood flow: 14.4+/-5.4 versus 13.5+/-5 mL x min[-1] x dL[-1]; P=.56) and was significantly (both P<.01) and equally blunted by L-NMMA in both groups (maximum blood flow: 11+/-3 mL x min[-1] x dL[-1] in normotensives versus 10.8+/-3.9 mL x min[-1] x dL[-1] in hypertensives; P=.77). The vasodilator response to sodium nitroprusside (0.8 to 3.2 microg/min), an exogenous NO donor, was similar in both groups and was not modified by L-NMMA. CONCLUSIONS: Hypertensive patients have impaired endothelium-dependent vasodilation in response to acetylcholine but preserved NO activity in response to beta-adrenergic stimulation. These findings suggest that the endothelial dysfunction in essential hypertension is due to a selective abnormality of NO synthesis, probably related to a defect in the phosphatidylinositol/Ca2+ signaling pathway.  相似文献   

15.
To evaluate left ventricular diastolic filling properties in elderly hypertensive case with left ventricular hypertrophy (LVH), we investigated the influence of postural change from a supine to sitting position on transmitral flow velocity profile as assessed by pulsed Doppler echocardiography in 12 normotensives (N group) and 24 hypertensives, aged 65 to 80 years. Hypertensive subjects were divided into two groups on the basis of left ventricular mass index (LVMI): 12 hypertensives without LVH (H1 group; LVMI < 130 g/m2); 12 hypertensives with LVH (H2 group; LVMI > 130 g/m2). Peak early filling velocity (E), peak atrial filling velocity (A) and the E/A ratio were similar in the three groups in the supine position. The postural change decreased E and A in N and H1 groups. On the other hand, the change decreased E, but not A in the H2 group. The E/A ratio was decreased in the H2 group compared with both the N and H1 group in the sitting position. As a result, the sitting position increased atrial contribution to diastolic filling in the H2 group. These observations indicate that a reduction in preload changes the transmitral flow velocity profile in elderly hypertensives with left ventricular hypertrophy. The Doppler alterations may be related to impaired left ventricular diastolic function.  相似文献   

16.
135 Black and White male and female normotensives and unmedicated mild to moderate hypertensives (aged 25–44 yrs) completed 4 reliable self-report scales. Ss also took part in 3 laboratory tasks that elicited cardiovascular reactivity. Ambulatory blood pressure (BP) readings at home and at work were also obtained from most Ss. Black and White Ss differed in their self-reports of anger/hostility and in their cardiovascular reactivity to behavioral tasks. In contrast, the relationships between self-reports of anger/hostility and cardiovascular activity at rest, during laboratory tasks, and at work varied as a function of race–sex combinations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

17.
Assessed the performance of 12 male hypertensives (mean age 47.36 yrs) in increasingly demanding interpersonal interactions. 12 extended role-played scenes incorporating the expression of positive and negative emotional states were used. Behavioral, physiological, and subjective ratings were obtained. Performance of the hypertensives was compared to that of both patient and nonpatient normotensive Ss who were carefully matched with the hypertensives on a number of demographic variables. Results indicate that the hypertensives responded less assertively on a number of dimensions than did the nonpatient comparison group. However, the performance of the normotensive patient group was similar to that of the hypertensive patients. Physiological and subjective data indicated comparable responding across all 3 experimental groups. The discussion focuses on the existence of a chronic-illness syndrome that potentially has strong behavioral correlates. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

18.
The mechanisms responsible for reduced arterial distensibility in renal transplant recipients remain to be evaluated. The present longitudinal study was aimed to evaluate the effect of hypertension on the evolution of vessel wall properties in renal transplant recipients. The mechanical properties of the common carotid artery were determined in 24 normotensive and 24 treated hypertensive renal transplant recipients 6-12 weeks after transplantation. The measurements were repeated after 2 years. Arterial distension was determined by using a multigate pulsed Doppler system, blood pressure (BP) was measured by a mercury sphygmomanometer. BP was 127 +/- 3/80 +/- 2 mm Hg at entry and 133 +/- 3/82 +/- 2 mm Hg after 2 years in the normotensive group, 146 +/- 4/90 +/- 3 mm Hg at entry and 145 +/- 3/87 +/- 2 mm Hg after 2 years in the hypertensive group (P < 0.01, normotensives vs hypertensives). The distensibility coefficient (DC) decreased significantly after 2 years in the hypertensive group (DC 18.3 +/- 1.3 10(-3)/kPa before, 15.1 +/- 1.2 10(-3)/kPa after 2 years, P < 0.05) whereas no significant change was observed in the normotensive group (DC 19.0 +/- 1.4 10(-3)/kPa before, DC 17.8 +/- 1.3 10(-3)/kPa after 2 years, NS). There was a significant correlation between the change of the distensibility coefficient after 2 years and mean arterial pressure (n = 48, r = 0.42, P < 0.01). The results show that the decrease of arterial distensibility after 2 years is accelerated in hypertensive renal transplant recipients despite effective anti-hypertensive treatment. Since BP levels were not different at entry into the study and after 2 years, differences in distending pressure along cannot explain the more pronounced decrease of arterial distensibility over time in hypertensive renal transplant recipients.  相似文献   

19.
To determine whether alpha1-blockade affects the forearm vascular resistance responses to lower body negative pressure (LBNP) in borderline hypertensives, six hypertensives (HTN; mean arterial pressure [MAP] = 109.9 +/- 1.7 mm Hg, mean +/- SE) and seven normotensives (NTN; MAP = 81.5 +/- 1.4 mm Hg) underwent exposures of LBNP at pressures of -10, -20, and -40 mm Hg during systemic alpha1-receptor blockade (BLK) and during placebo (PLA). Resting forearm vascular resistance (FVR) was greater in HTN than in NTN during PLA (34.8 +/- 5.4 v 17.5 +/- 3.1 units; P < .05), but not during BLK (28.1 +/- 5.2 v 25.3 +/- 9.9 units). When expressed as a percentage of resting FVR, LBNP evoked an increased FVR (P < .001) that did not differ significantly between BLK and PLA in either group. FVR was higher (P < .001) in HTN than in NTN throughout both trials; at -40 mm Hg of LBNP during BLK, the increase in FVR was greater (P < .05) in HTN than in NTN (131 +/- 42 v 48 +/- 15%). MAP (relative to resting) was maintained throughout LBNP during PLA but, at -40 mm Hg, was lower (P < .01) during BLK for both groups. HR was elevated in BLK and was increased at -40 mm Hg (P < .01) for each group in each trial. This increase was greater during BLK (P < .05). These data suggest that borderline hypertensives have a greater vasoconstrictor response to LBNP than do normotensives and alpha1-blockade does not appear to attenuate this response.  相似文献   

20.
AIM OF THE STUDY: To compare heart rate (HR) and blood pressure (BP) variability in hypertensives with or without left ventricular hypertrophy (LVH). METHODS: Thirty-three mild to moderate hypertensive patients, mean age 45 +/- 15 years, underwent an echocardiogram, a 24 hr ambulatory BP monitoring (ABPM), a 24 hr ECG monitoring and a continuous BP recording over 15 minutes both in supine and standing positions, by using digital plethysmography (Finapres device). Statistical analysis: non parametric tests. RESULTS: [table: see text] CONCLUSION: LVH is associated with a reduction in the markers of sympathetic activity and a decreased baroreflex sensitivity.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号