Effects of doxazosin on ambulatory blood pressure and sympathetic nervous activity in hypertensive Type 2 diabetic patients with overt nephropathy.

AIMS: Few studies have reported the effect of alpha(1)-adrenergic antagonists on 24-h blood pressure (BP) and sympathetic nervous activity in hypertensive patients with diabetic nephropathy. We assessed the effects of doxazosin on 24-h BP and spectral analysis of heart rate variability in hypertensive Type 2 diabetic patients with macroalbuminuria and compared the results with those in hypertensive Type 2 diabetic patients with normoalbuminuria and non-diabetic patients with essential hypertension. METHODS: Thirty-three patients in the macroalbuminuric group, 24 patients in the normoalbuminuric group, and 34 patients with essential hypertension underwent ambulatory BP monitoring before and after doxazosin treatment. Spectral analysis was performed to calculate the high-frequency (HF) components, a marker of parasympathetic nervous activity, and the low-frequency (LF) components, a marker of sympathetic nervous activity. RESULTS: Doxazosin decreased waking (from 158 +/- 17/88 +/- 10 to 148 +/- 15/80 +/- 7 mmHg, P = 0.001 for systolic and P < 0.001 for diastolic BP) and sleeping BP (146 +/- 20/79 +/- 10 to 137 +/- 17/72 +/- 9 mmHg, P < 0.001 and P < 0.001) in the macroalbuminuric group, but only decreased waking BP in the essential hypertension group (157 +/- 16/91 +/- 9 to 145 +/- 15/84 +/- 11 mmHg, P < 0.001 and P < 0.001) and normoalbuminuric group (159 +/- 15/89 +/- 9 to 150 +/- 16/82 +/- 10 mmHg, P = 0.014 and P < 0.001). Doxazosin decreased waking (from 1.48 +/- 0.11 to 1.42 +/- 0.12, P = 0.001) and sleeping (1.46 +/- 0.11 to 1.40 +/- 0.13, P = 0.001) LF components [unit: log(ms(2)/Hz)] only in the macroalbuminuric group without changing HF components. The normoalbuminuric and essential hypertension groups showed no differences (P = 0.637 and 0.492) in LF components during sleep. CONCLUSIONS: Doxazosin may be an antihypertensive agent that decreases both waking and sleeping BP through inhibiting sympathetic nervous activity in macroalbuminuric diabetes patients.     

Relationship between base blood pressure during sleep and health-related quality of life in healthy adults

There are many reports indicating that night time blood pressure (BP) is closely associated with target organ damage. However, BP in the waking period is influenced by physical activity and also by the psychological status. Recently, base BP (BP0: minimum and stable BP during sleep) has been reported to correlate with organ damage in hypertensives. However, little is known about the implications of BP0. We examined how BP0 is associated with BP, heart rate variability and health-related quality of life (HRQOL) in healthy subjects. One hundred and thirty-five participants, composed of 88 male and 47 female (age: 21-33 years) underwent a 24-h ambulatory BP monitoring (ABPM). Sympathetic nervous activity (ratio of low-frequency to high-frequency component: LF/HF) and parasympathetic nervous activity (high-frequency component: HF) were calculated by electrocardiogram monitoring. BP0 was calculated as previously reported. HRQOL was assessed by Medical Outcome Study Short-Forum 36-Item Health Survey. Base systolic BP (SBP0) positively correlated with 24-h systolic BP (SBP) (r=0.662, P<0.0001) and night time SBP (r=0.810, P<0.0001). SBP0 positively correlated with 24-h LF/HF (r=0.214, P<0.02) and night time LF/HF (r=0.326, P<0.001). Moreover, SBP0 negatively correlated with the scores of body pain (r=-0.223, P<0.02). Multiple linear regression analysis showed that SBP0 correlated with gender (P<0.01), night time LF/HF (P<0.04) and the scores of body pain (P<0.04). In conclusion, SBP0 correlated with BP, LF/HF and the scores of body pain (HRQOL). SBP0 may be a useful indicator for assessing 24-h BP, sympathetic nervous functions and HRQOL in healthy subjects.     

Circadian blood pressure variability is associated with autonomic and baroreflex-mediated modulation of the sinoatrial node

OBJECTIVE: The day-night variability of blood pressure (BP) is of interest in the analysis of ambulatory blood pressure monitoring (ABPM). The aim of this study was to investigate whether the nocturnal BP reduction was associated with the autonomic and baroreflex-mediated modulation of the sinoatrial node in normotensive and hypertensive subjects. METHODS AND RESULTS: 63 consecutive untreated male subjects (40 hypertensive and 23 normotensive) were studied. Spectral parameters of RR interval variability and the alphaLF index (a measure of baroreflex gain) were calculated at rest.Then all the subjects performed a 24-h ABPM. RESULTS: As regards the relationships involving 24-h BP and resting heart rate (HR) and HR variability parameters, a significant correlation was found between mean RR and both systolic and diastolic nocturnal BP falls (r = 0.40, p < 0.001, r = 0.32, p < 0.01, respectively); moreover, a significant correlation was found between the nocturnal fall of systolic BP and both the LF/HF ratio and absolute power of HF (r = -0.25, p < 0.05 and r = 0.29, p < 0.05, respectively). The alphaLF index was significantly associated with the nocturnal diastolic BP fall (r = 0.26, p < 0.05) whereas the association with the systolic fall did not reach statistical significance (r = 0.23, p = 0.07). CONCLUSIONS: The relationship found between the nocturnal reduction of BP and both the LF/HF ratio and HF power of RR variability suggests that factors influencing the sympatho-vagal modulation to the heart are associated with the day-night variability of blood pressure. Moreover, the relationship between BP fall and the spontaneous baroreflex sensitivity index alphaLF, may indicate a role of the baroreflex-mediated arc function in the BP adjustments occurring during the night.     

Circadian change of cardiac autonomic function in correlation with intra-esophageal pH

BACKGROUND AND AIM: Although autonomic alterations are observed in patients with gastroesophageal reflux disease (GERD), the influence of visceral receptor responses on the dynamics of autonomic function remains unknown. The aim of this study was to investigate the autonomic functional changes in association with intra-esophageal pH under ambulation. METHODS: Thirty patients referred for 48 h ambulatory pH monitoring underwent simultaneous 24 h cardiac monitoring for heart rate variability (HRV). We used linear mixed-effects models to estimate the relationship between esophageal acid exposure and power spectral analysis of HRV, including low-frequency power (0.04 < LF < 0.15 Hz), high-frequency power (0.15 < or = HF < 0.4 Hz), and LF/HF power ratio. RESULTS: Over the 24-h period, patients with pathological reflux had lower average LF and HF powers than patients with functional heartburn, but the LF/HF power ratios were similar for the two patient groups. As we stratified the data according to waking and sleeping times, a significantly higher HF power but lower LF/HF power ratio was found during sleeping time regardless of diagnosis. In the regression analysis, esophageal pH was positively associated with change (not basal tone) of both LF and HF powers during waking, but only with change of HF power during sleeping time. The significant associations between pH values and changes in HRV decreased gradually with time. The LF/HF power ratio did not alter significantly with pH. CONCLUSION: Esophageal acid exposure is generally associated with decreases in autonomic tone. A predominant parasympathetic fluctuation during sleeping and a superimposed sympathetic interaction during waking dictate diurnal characteristics of autonomic regulation.     

Effect of the angiotensin-converting enzyme inhibitor perindopril on 24-hour blood pressure in patients with lacunar infarction: comparison between dippers and non-dippers.

Antihypertensive therapy based on the angiotensin-converting enzyme (ACE) inhibitor perindopril reduced the incidence of recurrent stroke in the Perindopril Protection against Recurrent Stroke Study (PROGRESS). The present study assessed the effect of perindopril on the 24-h blood pressure (BP) in hypertensive patients with lacunar infarction using ambulatory BP monitoring (ABPM). There was a 4-week observation period, a 4-week treatment period 1 (perindopril at 2 mg/day), and a 4-week treatment period 2 (perindopril at 4 mg/day). Twenty-seven hypertensive patients with lacunar infarction (10 dippers and 17 non-dippers) were enrolled. The average 24-h BP values were significantly decreased after both treatment periods. When the patients were divided into dippers and non-dippers, perindopril exhibited a different BP-lowering effect in the groups with these two circadian BP patterns. In dippers, daytime BP was significantly decreased, whereas nighttime BP was not, so an excessive fall of nighttime BP was not observed. In non-dippers, both daytime and nighttime BP were decreased, with a stronger BP-lowering effect at night. There was a significant inverse correlation between the magnitude of the change in nighttime BP and the night/day ratio. These results suggested that perindopril could induce a sustained decrease of the 24-h BP in patients with lacunar infarction. In particular, a more pronounced nighttime BP-lowering effect was observed in non-dippers. As the incidence of non-dippers is reported to be high among patients with cerebrovascular disease, better nighttime BP control by perindopril might have helped to improve the outcome of such patients in PROGRESS.     

Pulse pressure or dipping pattern: which one is a better cardiovascular risk marker in resistant hypertension?

OBJECTIVE: Nocturnal blood pressure (BP) reduction and ambulatory pulse pressure (PP) are well known prognostic markers obtained from ambulatory BP monitoring (ABPM). The aim of this study is to investigate which one of these ABPM parameters is related to high cardiovascular risk profile in resistant hypertension, based on their associations with target organ damage (TOD). METHODS: Clinical-demographic, laboratory and ABPM variables were recorded in a cross-sectional study involving 907 resistant hypertensive patients. Nocturnal systolic BP reduction and 24-h PP were assessed both as continuous and dichotomized variables (PP at the upper tertile value: 63 mmHg). Statistical analyses included bivariate tests and multivariate logistic regression with each TOD as the dependent variable. RESULTS: Patients with the nondipping pattern and high 24-h PP shared some characteristics: they were older, had higher prevalence of cerebrovascular disease and nephropathy, higher office and 24-h BP levels, increased serum creatinine and microalbuminuria, and higher left ventricular mass index than their counterparts. Additionally, patients with high PP had a greater prevalence of diabetes and other TOD. In multivariate logistic regression, high PP was independently associated with all TODs even after adjustment for sex, age, BMI, cardiovascular risk factors, 24-h mean arterial pressure and antihypertensive treatment, whereas nondipping pattern was only associated with hypertensive nephropathy. Furthermore, PP was more strongly associated with the number of TOD than the nocturnal systolic blood pressure (SBP) fall. CONCLUSIONS: In a large group of resistant hypertensive patients, an increased 24-h PP shows a closer correlation with high cardiovascular risk profile than the nocturnal BP reduction.     

Spectral analysis of heart rate variability in elderly non-dipper hypertensive patients.

To assess by autoregressive model the frequency domain heart rate variability (HRV) during clinostatism and after passive orthostatic load (head-up tilt), 81 hypertensive and normotensive subjects (42 men and 39 women) were subdivided into four groups: 20 adult normotensive subjects (Group 1); 21 elderly normotensive subjects (Group 2); 20 elderly hypertensive subjects with nocturnal blood pressure (BP) falls (Group 3); and 20 elderly hypertensive subjects without nocturnal BP falls (Group 4). They were chosen to assess the influence of aging and arterial hypertension on sympathetic-parasympathetic balance. The age-related decrease observed in nearly all HRV spectral frequency components (normalised units [NUs], high frequency [HF] and low frequency [LF]) was reported in elderly patients in rest conditions. LF indexes resulted in decreases in Group 3 and these data seemed to be emphasised in Group 4. After passive tilt, spectral data were recorded as follows: 25.3+/-1.8 vs 17.8+/-2.2 HF, Group 2 vs Group 1, P<0.001; 72.5+/-0.8 vs 75.6+/-1.8 LF, P< 0.001, Group 2 vs Group 1. Both sympathetic and parasympathetic indexes were lower in Group 3 (44.6+/-1.1 vs 72.5+/-0.8 LF, P< 0.001, Group 3 vs Group 2; 9.9+/-1.8 vs 25.3+/-1.8 HF, P < 0.001, Group 3 vs Group 2) and data became clearer in Group 4 (8.5 2.1 vs 9.9+/-1.8 HF, P< 0.001; 40.4+/-1.5 vs 44.6+/-1.1 LF, Group 4 vs Group 3). The established influence of aging on autonomic nervous system activity appears to be increased by arterial hypertension due to worsening of the sympathetic-parasympathetic response to standardised stimulation. The loss of nocturnal BP declines in arterial hypertension was found to occur in association with a decrease in autonomic nervous system activity.     

Evaluation of morning blood pressure elevation and autonomic nervous activity in hypertensive patients using wavelet transform of heart rate variability.

To evaluate morning autonomic nervous activity and blood pressure profiles in hypertensive patients by analyzing heart rate variability and ambulatory blood pressure. Data from 82 patients with untreated essential hypertension were analyzed. We evaluated the 24-h profile of blood pressure and that of indices of autonomic nervous activity, i.e., the high frequency component (HF) and low frequency component/HF (LF/HF), which were obtained by wavelet transform of heart rate variability. Patients were classified by dipping status (nondippers, n=28; dippers, n=32; extreme-dippers, n=8; and risers, n=14) and morning blood pressure profile (large, n=9; small, n=60; and inverted, n=13). Nocturnal systolic blood pressure in extreme-dippers was significantly lower than that in the other groups; that in the risers was significantly higher (p<0.05). There were no significant group differences in daytime systolic blood pressure. Daytime and 24-h HF levels were significantly higher in the dipper vs. the riser group (p<0.05). Morning blood pressure elevation negatively correlated to preawake (p<0.01) and nocturnal blood pressure (p<0.05), but not to daytime and post-awake blood pressure. The preawake/postawake ratio of systolic blood pressure positively correlated to that of LF/HF (p<0.01) and negatively correlated to preawake HF levels (p<0.05). Multivariate regression analysis revealed that preawake HF levels (p=0.037) and preawake/postawake ratio of LF/HF (p=0.033) were independently correlated with morning blood pressure elevation ratio. Our results suggest that activation of HF before waking and LF/HF during waking might play an important role in the development of morning blood pressure elevation.     

Left ventricular mass and heart rate variability in middle-aged and elderly salt-sensitive hypertensive subjects

Previous reports have shown that in salt-sensitive hypertension a high dietary salt intake can increase sympathetic activity. We evaluated the influence of the autonomic nervous system on myocardial hypertrophy by power spectral analysis of heart rate variability in middle-aged and elderly salt-sensitive hypertensive subjects. We compared autonomic nervous system activity in 32 salt-sensitive hypertensive patients (15 subjects with mean age, 42.4+/-2.4 years and 17 subjects with mean age, 74.6+/-1.6 years) and 20 age-matched normotensive controls. Power spectral analysis detects four spectral components: total power (TP), high-frequency (HF), low-frequency (LF) and very-low-frequency (VLF) power. In the elderly subjects we found an association between the left ventricular mass index (LVMI) and the following variables: very-low frequency (P<0.0001), 24-h urinary sodium excretion (P<0.0001) and diastolic blood pressure (DBP) (P<0.0001). In contrast, in middle-aged subjects we found a significant association between the LVMI and LF (P<0.001). In middle-aged, but not in elderly salt-sensitive hypertensive subjects, increased sympathetic activity correlated with the LVMI (P<0.0001). Our findings suggest an association between sympathetic hyperactivity and the LVMI in middle-aged subjects with salt-sensitive hypertension.     

Effects of bedtime vs. morning administration of the long-acting lipophilic angiotensin-converting enzyme inhibitor trandolapril on morning blood pressure in hypertensive patients.

Cardiovascular events occur most frequently in the morning. To study the effects of the long-acting lipophilic angiotensin-converting enzyme (ACE) inhibitor trandolapril on morning blood pressure (BP), we performed ambulatory BP monitoring (ABPM) before and after administration of trandolapril just before going to bed (bedtime-administered group: n=17) or in the morning (morning-administered group: n=20) in 37 hypertensive patients. Both sets of ABPM data were available in 30 patients. The 24-h systolic BP (SBP) levels were significantly decreased by 7.2 mmHg in the morning-administered group (p=0.02) and by 5.2 mmHg in the bedtime-administered group (p=0.04). In the bedtime-administered group, prewaking SBP (the average of the 2-h SBP values just before waking) and morning SBP (the average of the 2-h SBP values just after waking) were significantly decreased by 11 mmHg (p=0.005) and by 8.4 mmHg (p=0.03), respectively. On the other hand, in the morning-administered group, the reduction of prewaking SBP (3.9 mmHg, n.s.) and morning SBP (6.6 mmHg, n.s.) did not reach the level of statistical significance. However, the differences in the reductions of prewaking and morning SBPs between the two groups were not statistically significant. There was no additional reduction of the nighttime lowest BP in either administration group. In conclusion, bedtime administration of the long-acting ACE inhibitor trandolapril seems to be a safe and effective means of controlling morning BP in hypertensive patients without an excessive fall in nocturnal BP.     

Evaluation of the activity of the autonomic nervous system in "dipper" and "non dipper" essential hypertensives. Gender differences]

OBJECTIVES: 1) To compare the autonomic nervous system activity parameters obtained from a photoplethysmographic recording in dipper and non dipper hypertensive. 2) To look for an interaction between dipper/non dipper status and gender. METHODS: Prospective study involving 245 untreated hypertensives (51 +/- 13 years, 146 men, 99 women). All of the patients underwent a 24-hour ambulatory blood pressure measurement (ABPM) as well as an echocardiography for left ventricular mass index determination (LVMI) and a photoplethysmographic recording of blood pressure (BP). Nondippers were defined as those whose nocturnal decrease in systolic BP (SBP) and/or diastolic BP (DBP) was < 10% of daytime BP. Spectral powers were obtained from the photoplethysmographic recording using a fast Fourier transform over the low frequency band (LF) and the high frequency band (HF). Baroreflex sensitivity (BRS) was evaluated by the sequences method. RESULTS: Of the 245 patients, 159 were dippers (98 men, 61 women) and 86 were non dippers (48 men and 38 women). Clinic BP was significantly higher in non dippers than in dippers (168/101 vs 161/98 mmHg; p < 0.01 for SBP and p < 0.05 for DBP) whereas daytime ABPM and LVMI were not different, whatever the gender. LF spectral powers were significantly lower in non dippers than in dippers for SBP (respectively 25 +/- 11% vs 30 +/- 13%; p < 0.01) for DBP (respectively 35 +/- 14% vs 41 +/- 15%; p < 0.01) and for HR (respectively 34 +/- 15% vs 38 +/- 15%; p = 0.03). They showed a positive correlation with the nocturnal SBP fall (r = 0.21, p < 0.001 for SBP and DBP spectral powers, r = 0.19; p < 0.005 for HR spectral power) and with the nocturnal DBP fall, too (r = 0.19; p < 0.005 for SBP spectral power, r = 0.20; p < 0.002 for DBP spectral power, r = 0.19; p < 0.005 for HR spectral power). HF spectral powers tended to be higher in non dippers than in dippers but in a non significative way. BRS was roughly the same in dippers and non dippers (7.5 +/- 2.7 vs 7.0 +/- 3.1 ms/mmHg, NS). The interaction between non dipper/dipper status and sex was non significant whatever the LF spectral power. CONCLUSIONS: 1) The greater the nocturnal BP fall, the higher the sympathetic activity indexes. 2) This relationship was found both in males and females.     

Aldosterone excess and resistance to 24-h blood pressure control

BACKGROUND: Aldosterone excess has been reported to be a common cause of resistant hypertension. To what degree this represents true treatment resistance is unknown. OBJECTIVE: The present study aimed to compare the 24-h ambulatory blood pressure monitoring (ABPM) levels in resistant hypertensive patients with or without hyperaldosteronism. METHODS: Two hundred and fifty-one patients with resistant hypertension were prospectively evaluated with an early-morning plasma renin activity (PRA), 24-h urinary aldosterone and sodium, and 24-h ABPM. Daytime, night-time, and 24-h blood pressure (BP) and nocturnal BP decline were determined. Hyperaldosteronism (H-Aldo) was defined as suppressed PRA (<1.0 ng/ml per h or <1.0 mug/l per h) and elevated 24-h urinary aldosterone excretion (>/= 12 mug/24-h or >/= 33.2 nmol/day) during ingestion of the patient's routine diet. RESULTS: In all patients, the mean office BP was 160.0 +/- 25.2/89.4 +/- 15.3 mmHg on an average of 4.2 medications. There was no difference in mean office BP between H-Aldo and normal aldosterone status (N-Aldo) patients. Daytime, night-time, and 24-h systolic and diastolic BP were significantly higher in H-Aldo compared to N-Aldo males. Daytime, night-time, and 24-h systolic BP were significantly higher in H-Aldo compared to N-Aldo females. Multivariate analysis indicated a significant interaction between age and aldosterone status such that the effects of aldosterone on ambulatory BP levels were more pronounced with increasing age. CONCLUSIONS: In spite of similar office BP, ABPM levels were higher in resistant hypertensive patients with H-Aldo. These results suggest that high aldosterone levels impart increased cardiovascular risk not reflected by office BP measurements.     

Relationship between short-term and long-term blood pressure variabilities in essential hypertensives

This study was designed to analyse the relationship between the different blood pressure (BP) variabilities obtained in a non-invasive way and to determine the potential contribution of aging, severity of hypertension and increased ventricular mass to these different BP variabilities. Two hundred and six hypertensive patients underwent a 24-h ambulatory BP measurement (ABPM) as well as a photoplethysmographic BP recording and a standard echocardiography. Nocturnal BP fall and standard deviations of hourly mean BP levels as well as post-prandial fall in BP were calculated from the 24-h ABPM and were considered as indexes of long-term variability. Baroreflex sensitivity (BRS) and spectral powers of systolic BP, diastolic BP and heart rate (HR) over the low frequency band (LF: 0.05--0.14 Hz) were obtained from photoplethysmographic recording and were used as indexes of short-term variability. Short-term variability indexes were shown to be significantly related to those of long-term variability. A decrease in LF spectral powers was associated with a particular profile characterised by an attenuation of nocturnal BP fall, an increase of daytime BP standard deviations, an increase in post-prandial BP fall, a decrease in BRS and to a lesser extent, a diminution in night-time HR standard deviation. Moreover, a negative significant relationship was found between standard deviation of daytime systolic BP and both night systolic BP fall and BRS. Age and nocturnal BP level were associated with all BP variability disorders, whereas left ventricular hypertrophy was associated only with a decrease in LF spectral powers and in night BP fall, and an increase in standard deviation of daytime BP. Finally, LF spectral power of SBP was identified as independently predicted by age and night SBP fall. Journal of Human Hypertension (2001) 15, 41-48     

Effect of losartan on nocturnal blood pressure in patients with stroke: comparison with angiotensin converting enzyme inhibitor

BACKGROUND: Treatment of nocturnal hypertension has been reported to be beneficial for primary and secondary prevention of stroke. We compared the effects of angiotensin II antagonist (losartan) and angiotensin converting enzyme inhibitor (quinapril) on nocturnal blood pressure (BP) and sympathetic nervous activity in patients with hypertension and stroke. METHODS: According to a prospective, randomized, cross-over design, 30 hypertensive patients with a previous history of stroke (25 hemorrhage, 5 infarction) were assigned randomly to receive losartan (50 mg) or quinapril (10 mg) once daily for 4 weeks. The patients were switched to the alternative regimen for an additional 4-week period. In the last week of each treatment, 24-h ambulatory BP monitoring was performed every 30 min, and 24-h urine was collected for the measurement of catecholamine. RESULTS: Neither systolic nor diastolic BP during daytime differed between losartan and quinapril treatments, but those during nighttime were lower with losartan treatment than with quinapril treatment. The nocturnal decreases in systolic and diastolic BP were both greater with losartan treatment than with quinapril treatment (systolic BP: 6.1% +/- 5.9% v 2.5% +/- 6.9%, diastolic BP: 6.4% +/- 6.5% v 3.3% +/- 7.8%, both P <.05). The nocturnal decrease in urinary norepinephrine excretion was greater with losartan treatment than with quinapril treatment (52.8% +/- 9.7% v 42.8% +/- 17.2%, P <.05). CONCLUSIONS: Losartan enhances the nocturnal decrease in ambulatory BP compared with that of quinapril in patients with a previous history of stroke presumably by way of the suppression of nocturnal sympathetic nervous activity.     

Peculiarities of regulatory mechanisms of autonomic nervous system in patients with arterial hypertension and disturbed 24-hour blood pressure profile

BACKGROUND: Insufficient nocturnal blood pressure (BP) decline is associated with elevated risk of complications of hypertensive disease. Heart rate variability (HRV) reflects activity of sympathetic and parasympathetic parts of autonomic nervous system. AIM: To elucidate special characteristics of HRV in patients with various types of 24-hour BP rhythm. Material and methods. Bifunctional 24-hour monitoring and echocardiography were carried out in 42 men with stage I-II hypertensive disease and I-II degree of arterial hypertension (mean age 21.7+/-4.5 years) and 16 practically healthy young people (mean age 24.6+/-5.2 years). RESULTS: Subjects with insufficient (<10%) and adequate nocturnal BP decline (non-dippers and dippers) were distinguished (groups ND and D, respectively). Patients with hypertension in group ND had elevation of systolic BP variability during night and day time, augmentation of nocturnal and diurnal HRV low frequency power, lowering of nocturnal high frequency power, lowering of pNN50 and rMSSD values at night. HRV parameters of control subjects in this group did not differ from those of healthy people. All HRV parameters in group D were characterized by significant 24-hour rhythmicity. This rhythmicity was substantially disturbed in patients of group ND. Parameters of central hemodynamics were similar in groups D and ND. CONCLUSION: These results evidence for the presence of enhanced activity of sympathetic part of autonomic nervous system in non-dipper patients with hypertensive disease throughout 24 hours and during night time and for disturbed circadian rhythm of autonomic nervous system activity. This can serve as a basis for increased rate of cardiovascular complications in this category of patients.     

Clinical experience with perindopril in African-American hypertensive patients: a large United States community trial

BACKGROUND: The prevalence of hypertension is greater in African Americans, and management of this condition presents challenges for practicing physicians. METHODS: The effectiveness and safety of perindopril was evaluated in hypertensive African-American patients (n = 1412) and hypertensive white patients (n = 7745) who had participated in a large United States community trial. Patients received perindopril 4 mg once daily for 6 weeks. Based on physicians' clinical judgment at week 6, the dose was either maintained or increased to 8 mg for an additional 6 weeks. RESULTS: Reduction of blood pressure (BP) was significant with perindopril monotherapy (4 to 8 mg once daily) in African Americans and whites (P <.001). The magnitude of BP reduction was significantly more in whites (P <.001). Up-titration of perindopril achieved additional BP reduction in both ethnic groups (P <.001). Control of BP (<140/90 mm Hg) in elderly (>65 years of age) and diabetic African-Americans subgroups was achieved in 32.1% and 31.6%, respectively. Perindopril was safe and well tolerated. CONCLUSIONS: Perindopril monotherapy is effective and is a viable initial therapeutic option as an antihypertensive agent in African-American individuals with hypertension.     

Twenty-four-hour ambulatory blood pressure monitoring efficacy of perindopril/indapamide first-line combination in hypertensive patients: the REASON study

BACKGROUND: Circadian blood pressure (BP) measurements provide more information on hypertensive complications than office BP measurements. The purpose of this study was to analyze the efficacy of the first-line combination of perindopril 2 mg plus indapamide 0.625 mg versus atenolol 50 mg on BP parameters and variability over 24 h in patients with hypertension. METHODS: A double-blind, randomized, controlled, 12-month study comparing perindopril/indapamide and atenolol was performed in 201 patients (age 55.0 years) with uncomplicated sustained essential hypertension. Ambulatory BP measurements (ABPM) were done every 15 min over 24 h. RESULTS: After 1 year of treatment, the decrease in systolic BP was significantly greater for perindopril/indapamide than for atenolol during the entire 24-h period (-13.8 v -9.2 mm Hg), the daytime and the nighttime periods (P <.01). Diastolic blood pressure (DBP) variations were comparable for the two groups (-7.2 v -8.3 mm Hg, NS). Pulse pressure (PP) reduction was also significantly greater for perindopril/indapamide than for atenolol (for the whole 24 h, -6.6 v -0.9 mm Hg, P <.001). The through to peak (T/P) BP ratio and the smoothness index were comparable in the two groups for DBP. For systolic blood pressure (SBP), higher values of the T/P ratio (0.80 v 0.59) and the smoothness index (1.45 v 0.98; P <.02) were achieved for the perindopril/indapamide combination than for atenolol. CONCLUSIONS: The perindopril/indapamide first-line combination decreased SBP and PP more effectively than atenolol. Moreover, the BP control effect was smooth and consistent throughout the 24-h dosing interval and BP reduction variability was lower than the one induced by atenolol.     

Relation between 24-h heart rate variability and blood pressure fluctuation during exercise in stroke patients.

BACKGROUND: In some stroke patients blood pressure (BP) fluctuates extensively during medical rehabilitation, so the present study investigated the influence of autonomic nervous dysfunction on the change in BP during exercise. METHODS AND RESULTS: The subjects consisted of 55 stroke inpatients (males, 29; mean age, 58.8 years old; ischemic/hemorrhagic etiology, 30/25) who were admitted to the Stroke Center within 2 weeks of their first stroke. The control group consisted of 15 age-matched healthy volunteers. The 24-h heart rate (HR) variability (HRV) and BP variability (BPV) were examined, and then the increase and recovery of BP and HR were measured during bicycle ergometer exercise at 4 METs. Components of 24-h HRV (low-frequency power (LF), high-frequency power (HF), LF/HF, and asleep-awake ratio of LF/HF (LF/HF(d-n)) were lower (p < 0.01) and BPV was greater in the stroke group (p < 0.05) than in the control group. There was a negative correlation between BP change during exercise and LF/HF or LF/HF(d-n) (r = -0.43 or r = -0.58, p < 0.01), and a greater increase in systolic BP (102 +/-9.8 mmHg, n = 7) during exercise was observed in stroke patients with lower LF/HF(d-n) (< or = 1.0). CONCLUSIONS: Lower HRV in stroke patients may relate to an increase in BP during exercise. HRV is useful for estimating the risk during medical rehabilitation.     

Effects of insufficient sleep on blood pressure in hypertensive patients: A 24-h study

The influence of acute sleep deprivation during the first part of the night on 24-h blood pressure monitoring (ABPM) was studied in 36 never-treated mild to moderate hypertensive patients. According to a crossover design, they were randomized to have either sleep deprivation or a full night’s sleep 1 week apart, during which they were monitored with ABPM. Urine samples for analysis of nocturnal urinary excretion of norepinephrine were collected. During the sleep-deprivation day, both mean 24-h blood pressure and mean 24-h heart rate were higher in comparison with those recorded during the routine workday, the difference being more pronounced during the nighttime (P < .01). Urinary excretion of norepinephrine showed a significant increase at night during sleep deprivation (P < .05). Blood pressure and heart rate significantly increased in the morning after a sleep-insufficient night (P < .05). These data suggest that lack of sleep in hypertensive patients may increase sympathetic nervous activity during the night and the following morning, leading to increased blood pressure and heart rate. This situation might represent an increased risk for both target organ damage and acute cardiovascular diseases.     

Long-term development of blood pressure profile in hypertensive hemodialysis patients

OBJECTIVE: The prognostic value of nocturnal blood pressure (BP) in hemodialysis patients has been well established. The aim of this study was to evaluate the long-term outcome of ambulatory BP in hypertensive hemodialysis patients. DESIGN AND METHODS: Medical records of all hemodialysis patients seen for uncontrolled hypertension between 1993 and 1999 and who underwent an ambulatory blood pressure measurements (ABPM) were retrospectively studied. Uncontrolled hypertension was defined as office BP = 140/90 mmHg and 24 h ABP = 125/80 mmHg. Patients who underwent a second ABPM after an interval of at least 1 year were included in the study. Demographic characteristics, medical history, cardiovascular risk factors and treatments were recorded for each patient. A t-test (bilateral) was used to compare BP. RESULTS: 26 patients were included (545 +/- 18.9 years; 14 men). 7 had previous history of cardiovascular disease and 2 were diabetic. At the end of the follow-up (29 +/- 12.8 months), 9 patients (36%) had 24 h BP < 125/80 mmHg. A significant decrease in diurnal and nocturnal BP was observed (p < 0.05). No significant change was observed for office systolic BP and predialytic BP. CONCLUSION: Our data show that a long-term decrease in nocturnal BP can be obtained in hypertensive patients on hemodialysis. With respect to the prognostic value of this criteria, randomised trials could be carried out to determine whether nocturnal BP is superior to office BP as a target for antihypertensive therapy in this population.