Ambulatory blood pressure, nocturnal blood pressure reduction and plasma catecholamines

OBJECTIVE AND DESIGN: Controversial data have been reported on plasma catecholamines in hypertensives. Aims of this study were to find whether 24-hour ambulatory blood pressure was correlated with circulating catecholamines and to investigate whether nocturnal blood pressure reduction was associated with baseline plasma catecholamines. Samples for catecholamine determination were obtained in 34 consecutive male subjects after a 30-minute rest and before ambulatory blood pressure monitoring. RESULTS: Hypertensive patients (n = 22; 24-hour blood pressure: 145 +/- 14/94 +/- 6 mm Hg) showed similar norepinephrine and epinephrine levels when compared with normotensives (n = 12; 24-hour blood pressure: 124 +/- 6/81 +/- 6 mm Hg), and higher dopamine values (hypertensives: 64.6 +/- 58; normotensives: 26.2 +/- 31 pg/ml; p < 0.05). A positive correlation was observed between dopamine and diastolic nocturnal blood pressure (p < 0.05) while a negative correlation was found between dopamine and nocturnal diastolic blood pressure reduction (p < 0.025). No significant relationship was observed between both norepinephrine and epinephrine, and 24-hour blood pressures. CONCLUSIONS: Since previous reports have documented malfunctioning of dopaminergic system in hypertension, the higher levels of circulating plasma dopamine found in hypertensive patients in the present study may account for a peripheral compensatory increase. The correlation between dopamine and nocturnal blood pressure fall seems to indicate that the impairment of dopaminergic system may influence the 24-hour blood pressure profile, affecting the nocturnal blood pressure reduction.     

Nocturnal blood pressure and relation to vasoactive hormones and renal function in hypertension and chronic renal failure

The purpose of this study was to assess the blood pressure profile and to measure vasoactive hormones in patients with essential hypertension (n=61), secondary hypertension (n=32) and chronic renal failure (n=32) matched with healthy control subjects (n=35), and to study the relationship between circadian changes in blood pressure and baseline levels of vasoactive hormones and renal function. Non-invasive, automatic blood pressure measurement was performed for 24 or 48 h. Venous plasma concentrations of renin, angiotensin II, aldosterone, arginine vasopressin, atrial natriuretic peptide and endothelin were measured. The mean 24-h blood pressure was higher in all groups of hypertensive patients than in control subjects. The nocturnal blood pressure fall was preserved in essential hypertension, in contrast to secondary hypertension in which it was attenuated. In the patients with chronic renal failure the 24-h mean blood pressure was the same as in the controls. Night-time blood pressure was higher among the chronic renal failure patients than in the control group, and the nightly blood pressure fall in both diastolic and systolic blood pressure was reduced. Plasma concentrations of renin activity, arginine vasopressin, atrial natriuretic peptide, aldosterone and endothelin were significantly increased in secondary hypertension and chronic renal failure, compared to essential hypertension and control subjects. Plasma angiotensin II was increased in chronic renal failure compared to essential hypertension and controls. Estimated creatinine clearance and nightly blood pressure dips were inversely correlated in essential and secondary hypertension, i.e. with a decreasing renal function both systolic and diastolic nightly blood pressure dips were gradually attenuated. In the whole group of patients the nightly systolic and diastolic blood pressure dips were negatively correlated to basal plasma renin activity, plasma aldosterone and atrial natriuretic peptide levels, i.e. the higher the basal plasma hormone level the lower the blood pressure dip. In conclusion, patients with essential hypertension have elevated but normally configured 24-h blood pressure profiles, and patients with different kinds of secondary hypertension have elevated 24-h blood pressure profiles and attenuated nightly systolic and diastolic blood pressure falls. The more the renal function is reduced and the more the plasma levels of renin and aldosterone are increased, the more the nocturnal fall in blood pressure is reduced. It is suggested that the attenuated or absent decrease in nocturnal blood pressure in secondary renal hypertension is caused by an abnormally increased secretion of vasoactive hormones and/or by so far unknown factors released from the diseased kidney.     

Cardiovascular outcome in white-coat versus sustained mild hypertension: a 10-year follow-up study

BACKGROUND: The aim of this study was to compare the risk conferred by white-coat versus sustained mild hypertension for the development of cardiovascular disease. METHODS AND RESULTS: Patients (n=479) who underwent 24-hour intra-arterial ambulatory blood pressure monitoring on the basis of a persistently elevated clinic systolic blood pressure of 140 to 180 mm Hg were followed up for the development of subsequent cardiovascular events during a 9.1+/-4. 2-year period. White-coat hypertension, defined as a clinic systolic blood pressure of 140 to 180 mm Hg associated with a 24-hour ambulatory systolic blood pressure <140 mm Hg and diastolic blood pressure <90 mm Hg, was present in 126 patients, and the remainder had sustained mild hypertension. A subgroup of patients without complications underwent follow-up echocardiography and carotid ultrasound. White-coat hypertensives were younger (44+/-12 versus 52+/-10 years, respectively; P<0.001) and had a significantly lower incidence of cardiovascular events (1.32 versus 2.56 events per 100 patient-years, respectively; P<0.001) than sustained hypertensives. Multivariate analysis revealed age (P=0.002), sex (P=0.007), race (P=0.001), smoking (P=0.005), and the presence of white-coat hypertension (hazard ratio, 0.29; 95% CI, 0.09 to 0.90; P=0.04) to be independent predictors of subsequent cardiovascular events. Subgroup analysis in patients without complications revealed a lower incidence of left ventricular hypertrophy and lesser degrees of carotid hypertrophy in the white-coat group. CONCLUSIONS: These findings indicate a relatively benign outcome in white-coat hypertension compared with sustained mild hypertension.     

Plasma levels of natriuretic peptides and adrenomedullin in elderly hypertensive patients: relationships to 24 h blood pressure

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.     

Adverse prognostic value of a blunted circadian rhythm of heart rate in essential hypertension

BACKGROUND: Previous studies revealed a direct association between resting heart rate and risk of mortality in essential hypertension. However, resting heart rate is a highly variable measure since it is affected by the alerting reaction to the visit. OBJECTIVE: To investigate whether the heart rate values recorded during the 24 h of ambulatory blood pressure monitoring are independent predictors of survival of uncomplicated subjects with essential hypertension. METHODS: We followed up 1942 initially untreated and uncomplicated subjects with essential hypertension (mean age 51.7 years, 52% men) for an average of 3.6 years (range 0-10 years). All subjects underwent baseline procedures including 24 h non-invasive blood pressure monitoring with simultaneous assessment of heart rate, one reading every 15 min for 24 h. MAIN OUTCOME MEASURES: All-cause mortality and cardiovascular morbidity. RESULTS: During follow-up there were 74 deaths from all causes (1.06 per 100 person-years) and 182 total (fatal plus non-fatal) cardiovascular morbid events (2.66 per 100 person-years). Clinic, average 24 h, daytime and night-time heart rates exhibited no association with total mortality. However, the subjects who subsequently died had had a blunted reduction of heart rate on going from day to night during the baseline examination. After adjustment for age (P < 0.001), diabetes (P < 0.001) and average 24 h systolic blood pressure (SBP, P= 0.002) in a Cox model, for each 10% less reduction in the heart rate from day to night the relative risk of mortality was 1.30 (95% confidence interval 1.02-1.65, P = 0.04). Rates of death were 0.38, 0.71, 0.94 and 2.0 per 100 person-years among subjects in the four quartiles of the distribution of the percentage reduction in heart rate from day to night The baseline day-night changes in the heart rate exhibited an inverse correlation to age and to clinic and ambulatory SBP and a direct association with the day-night changes in blood pressure. The degree of reduction of heart rate from day to night also had an independent inverse association with total cardiovascular morbidity after adjustment for age, diabetes and left ventricular hypertrophy, but this association did not remain significant when average 24 h SBP and the degree of day-night reduction in SBP were entered into the equation. CONCLUSIONS: A flattened diurnal rhythm of heart rate in uncomplicated subjects with essential hypertension is a marker of risk for subsequent all-cause mortality and this association persists after adjustment for several risk factors. For assessing these subjects, a limited and uniformly distributed period of ambulatory heart rate recording during the 24 h is clinically valuable.     

The influence of 5-week relaxation therapy on arterial blood pressure in patients with borderline hypertension

The present study was performed to evaluate the influence of 5-week relaxation therapy on office and ambulatory blood pressure in young borderline hypertensives. Thirty patients were studied. The office blood pressure decreased significantly after 5 weeks of relaxation therapy (P < 0.001 for both systolic and diastolic blood pressure). Ambulatory monitoring revealed only a slight decrease of 24-hour blood pressure (P = 0.02). Our results indicate limited efficacy of relaxation therapy in treatment of borderline hypertensives.     

Phosphatidylinositol 4-kinase of Torpedo californica electrocytes: physico-chemical characterization and regulation by calcium and vicinal molecules of phosphatidylinositol

The kidney is an important target of hypertension-induced organ damage. Recent long-term observation studies have documented that in individuals, without primary chronic renal disease, a very significant relationship exists between hypertension and impaired renal function, elderly hypertensives having a particularly worse prognosis. The hallmark of hypertensive renal injury is thought to be a progressive increase in intrarenal vascular resistance. The alterations in renal hemodynamics are accentuated in elderly patients with essential hypertension, pointing to a greater vulnerability of the senescent kidney to superimposed injury such as high blood pressure. Treatment of elevated blood pressure in the elderly therefore not only reduces cardiovascular morbidity and mortality, but also reduces the incidence of renal failure as a consequence of hypertension-induced damage.     

Inhibition of plasma endothelin-1 concentration by captopril in patients with essential hypertension

The aim of this study was to determine whether captopril has any effect on plasma endothelin-1 (ET-1) concentration in patients with essential hypertension. Nine normotensives and eleven hypertensives were included in this study. Blood pressure and pulse rate were monitored before and at 60 min after captopril ingestion (25 mg). Simultaneously, blood samples for plasma ET-1 and plasma renin activity (PRA) determination were obtained. In the normotensives, captopril treatment resulted in a significant rise in PRA, but without statistical changes in blood pressure and plasma ET-1. By contrast, in the hypertensives, although PRA elevated similarly after captopril, both blood pressure and plasma ET-1 decreased significantly compared with their respective preloading level. These data suggest that the blood pressure-lowering effect of captopril in essential hypertension may be at least in part, mediated by its inhibition of ET-1 production from the vascular endothelium.     

Medication use in nursing homes for elderly people

The aim of this cross-sectional study which took place in a hypertension clinic at a district general hospital in Denmark was to make a pragmatic definition of white coat hypertension. A total of 420 patients were referred consecutively from general practice with newly diagnosed untreated essential hypertension and 146 normal subjects were drawn at random from the Danish national register. The following measurements were taken: office blood pressure; 24-h ambulatory blood pressure (BP) monitoring; echocardiography with determination of left ventricular mass index and relative wall thickness; and early morning urine albumin/creatinine ratios. Four different cut-off levels were studied. An ambulatory daytime BP of 135.6/90.4 mm Hg was found to correspond to an office BP of 140/90 mm Hg in normal controls; used as a cut-off level in patients with newly diagnosed hypertension it separated 19% as white coat hypertensives. The end-organ involvement of these white coat hypertensives differed significantly from those with established hypertension but not from the normal controls. Lower cut-off levels were less efficient in this respect, as was the case when the systolic BP was not taken into account. In conclusion a pragmatic definition of white coat hypertension should--apart from well-established hypertensive office measurements--include a cut-off level close to 135/90 mm Hg ambulatory daytime BP.     

Pelvic congestion syndrome: early clinical results after transcatheter ovarian vein embolization

The contributing role of vascular endothelium in the development of hypertension-related vascular damage is well accepted. Salt-sensitive hypertension is characterized by a cluster of renal, hormonal, and metabolic derangements that might favor the development of cardiovascular and renal damage. To evaluate endothelial involvement in salt-sensitive essential hypertension, plasma levels of several markers of endothelial damage such as endothelin-1 (ET-1), von Willebrand factor (vWf), and soluble (S-) adhesion molecules E-selectin, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and 24-hour urinary albumin excretion (UAE) were measured in 39 nondiabetic, nonobese, never-treated essential hypertensive patients after intermediate (120 mmol/d), high (220 mmol/d), and low (20 mmol/d) NaCl diets. Patients were classified as salt sensitive (n=18) or salt resistant (n=21) according to their blood pressure responses to changes in dietary NaCl intake. Salt-sensitive hypertensives showed higher plasma ET-1 (P<0.05), vWf (P<0.005), and S-E-selectin levels (P<0.04) and increased UAE (P<0.05) than salt-resistant hypertensives. By contrast, circulating S-ICAM-1 and S-VCAM-1 concentrations were not significantly higher in salt-sensitive (596. 56+/-177.05 ng/mL and 541.06+/-157.84 ng/mL, respectively) than salt-resistant patients (516.86+/-147.99 ng/mL and 449.48+/-158.91 ng/mL, respectively). During the intermediate NaCl diet, plasma ET-1 responses to oral glucose load were greater in salt-sensitive (P<0. 05) than in salt-resistant patients. A marked (P<0.05) hyperinsulinemic response to oral glucose load was evident in salt-sensitive but not salt-resistant patients after each diet. This study shows increased plasma levels of the endothelium-derived substances E-selectin, vWf, and ET-1 in salt-sensitive hypertensives. Our findings support the hypothesis that salt sensitivity is correlated with an increased risk for developing hypertension-related cardiovascular damage.     

Diagnosing gestational hypertension and preeclampsia with the 24-hour mean of blood pressure

The use of ambulatory blood pressure monitoring has provided a method of blood pressure assessment that may compensate for some of the limitations of isolated measurements. Here we aim to examine prospectively the effectiveness of the commonly used 24-hour mean as a potential screening test for the identification of gestational hypertension and preeclampsia. We analyzed 503 blood pressure series from 71 healthy pregnant women and 256 series from 42 women who developed gestational hypertension or preeclampsia. Forty-eight-hour blood pressure monitoring was done once every 4 weeks after the first obstetric consultation. Sensitivity and specificity of the 24-hour mean of blood pressure were computed for each trimester of pregnancy by comparing distributions of values obtained for healthy and complicated pregnancies, without assuming an a priori threshold for diagnosing gestational hypertension on the basis of mean blood pressure. Sensitivity ranges from 31.8% for diastolic blood pressure in the second trimester to 84.1% for systolic blood pressure in the third trimester. However, specificity is as low as 6.9% for diastolic blood pressure in the first trimester. The positive predictive value does not reach 55% for any variable in any trimester. The higher relative risk was consistently obtained for systolic blood pressure (4.9 in the third trimester). Despite the highly statistically significant differences in blood pressure found between healthy and complicated pregnancies in all trimesters, the daily mean of blood pressure does not provide a proper and stable individualized test for diagnosing hypertensive complications in pregnancy. Other indexes obtained from the blood pressure series have been shown, however, to identify early in pregnancy those women who subsequently will develop gestational hypertension or preeclampsia, rendering ambulatory blood pressure monitoring a useful, but still costly, technique in pregnancy.     

Ethnic differences in the hypertensive heart and 24-hour blood pressure profile

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.     

Elevated plasma catecholamines without alteration in cardiovascular responsiveness in young men with borderline hypertension

Plasma catecholamines and cardiovascular responses to upright posture, exogenous noradrenaline (NA), and isoproterenol (IP) were examined in 20 young men with borderline hypertension and in 10 age-matched normotensive volunteers. Resting plasma NA and adrenaline (Ad) levels were higher in the borderline hypertensive patients. Significant correlations were found among plasma NA and mean blood pressure (MBP) or heart rate (HR), and between plasma Ad and HR in all individuals in the supine position. The increases in plasma NA were similar between groups for orthostatic positions. Pressor response to exogenous NA and chronotropic response to exogenous IP were not augmented in borderline hypertensives. A negative correlation was found between plasma NA before infusion and the increases of MBP produced by NA or the increases of HR produced by IP in all the individuals. Our observations suggest that there is hyperactivity of the sympathoadrenal system without enhancement in cardiovascular reactivity to catecholamines in young men with borderline hypertension.     

Twenty-four-hour blood pressure profile and blood pressure responses to head-up tilt tests in Parkinson's disease and multiple system atrophy

OBJECTIVE: To investigate the 24 h blood pressure profile in patients with Parkinson's disease with intact autonomic function or with autonomic failure and patients with multiple system atrophy (MSA), and to assess whether these patients exhibit posture-related variations in blood pressure. PATIENTS AND METHODS: We studied 24 patients with Parkinson's disease (11 with autonomic failure) and 13 patients with MSA (all with autonomic failure). Autonomic failure was determined by autonomic tests. An oscillometric recorder was used for ambulatory blood pressure monitoring. Tilt-table tests were performed with a head-up tilt position of 60 degrees. RESULTS: An alteration in the normal 24 h blood pressure profile was observed in 82% of Parkinson's disease patients with autonomic failure and in 85% of those with multiple system atrophy, but not in the patients with intact autonomic function. Head-up tilt tests revealed a significantly higher supine blood pressure in Parkinson's disease patients with autonomic failure and in those with MSA than in Parkinson's disease patients with intact autonomic function. Tilting resulted in a marked fall in blood pressure in patients with MSA; in Parkinson's disease patients with autonomic failure, the fall was comparatively slighter. CONCLUSIONS: We conclude that autonomic failure contributes to the alterations in the day-night blood pressure profile that may possibly be ascribed to postural dysregulation of blood pressure. We hypothesize that nocturnal hypertension is a risk factor in the development of additional cerebrovascular disease in patients with Parkinson's disease or MSA who are affected by autonomic failure.     

Basal nitric oxide synthesis in essential hypertension

BACKGROUND: There is indirect evidence that nitric oxide (NO) synthesis in vascular endothelium of patients with hypertension is altered. The aim of this study was to estimate more directly NO production in patients with untreated essential hypertension by measurement of synthesis of inorganic nitrate, which is the end product of NO oxidation in humans. Two separate studies were undertaken in patients with hypertension and appropriate healthy controls. METHODS: In the first study, ten patients and 13 controls were given a diet containing 82 mumoles nitrate per day for 2 days, with urinary and plasma nitrate measurement and 24 h ambulatory blood pressure monitoring on the 2nd day. In the second study, 11 patients and 11 controls were studied in the postabsorptive state; a bolus of 200 mg L[15N]2 arginine was administered intravenously over 10 min. 24 h ambulatory blood pressure monitoring was done and complete urine collections were made for the next 36 h. FINDINGS: In the first study, 24 h urinary nitrate excretion was lower in the hypertensive patients than in the control group (mean 450 [SEM 37] vs 760 mumoles [77] per 24 h; p < 0.001). There was an inverse correlation between average mean daytime ambulatory blood pressure and nitrate excretion (p = 0.007; r2 = -0.73). In the second study, mean 36 h urinary 15N nitrate excretion was significantly lower in the hypertensive than in the control group (1313 [50] vs 2133 [142] pmoles; p < 0.001). There was an inverse correlation also between average mean daytime ambulatory blood pressure and 24 h urinary 15N nitrate excretion expressed per mmole of creatinine (p = 0.002, r2 = -0.59). In addition, total urinary 15N nitrate excretion in the hypertensive group was significantly higher in women than in men (285 [16] vs 198 [14] micrograms 15N nitrate per kg; p = 0.026). INTERPRETATION: These data suggest that whole-body NO production in patients with essential hypertension is diminished under basal conditions. The origin of the NO we measured is not known, and we cannot tell whether the impaired synthesis is primary or secondary to a rise in blood pressure.     

Imaging of renal graft lymphomas. Apropos of 5 cases]

OBJECTIVE: To test the hypothesis that heavy smoking may interfere with the variation in ambulatory blood pressure (ABP) and sympathetic nervous system in essential hypertension. METHODS: We compared the office and 24-hour ABP of 48 untreated hypertensive smokers (> 20 cigarettes daily) with 90 non-smoking hypertensives matched for age, sex and body mass index. ABP was recorded using fully automatic SpaceLabs 90,207 units set to take a measurement every 15 minutes during the day (7.00 a.m.-10.00 p.m.) and every 20 minutes during the night (10.00 p.m.-7.00 a.m.). Urine collection for urinary sodium, potassium, epinephrine and norepinephrine excretion was performed during the 24-hour period of ABP monitoring. Catecholamines were measured by high pressure liquid chromatography. RESULTS: The office blood pressure readings of the smoking and non-smoking groups were 156.7/103.4 and 156.5/103.9 mmHg respectively. During the day-time period, ambulatory systolic and diastolic blood pressure was significantly higher in the smokers (146 +/- 12 vs 140.4 +/- 13 mmHg, p < 0.02; 96.4 +/- 8.15 vs 93.1 +/- 10 mmHg, p < 0.05 respectively). This difference was greater among patients under the age of 50 (145.9 +/- 13 vs 136.6 +/- 11 mmHg, p < 0.001 and 97.1 +/- 8.7 vs 92.3 +/- 9.9 mmHg, p < 0.02). Blood pressure during the night-time period did not differ between the two groups (130.5/81.3 vs 126.3/79.5). No differences were detected among the groups as far as urinary catecholamine excretion is concerned. CONCLUSION: Our data suggest that among hypertensive subjects, smokers maintain a higher day-time ambulatory systolic and diastolic blood pressure than non-smokers, particularly in the younger patients, even though casual blood pressure is similar.     

Continuous ambulatory measurement of blood pressure in children--personal experience

Ambulatory blood pressure monitoring (ABPM) during normal daily activities and during night, when the patient is asleep, is a new method of measuring blood pressure (BP) in children, used for better diagnosis and treatment of hypertension. Compared to casual BP measurements, it documents normal daily BP variations, BP during sleep, the influence of emotional and physical stress on BP and is a better predictor of hypertension associated with end-organ damage. However, the experience in ABPM in children is still limited. In our country ABPM has been used since recently, and first results are referred to children with end-stage renal failure. SUBJECTS AND METHODS: ABPM was performed in two groups of children: group A consisted of 61 children, aged 14.3 +/- 2.9 (mean +/- SD) yrs in whom intermittent outpatient BP measurements (for at least 3 months) suggested the diagnosis of hypertension (according to the data of Second Task Force); group B consisted of 52 patients (pts), aged 12.8 +/- 4.6 yr with renal disease. Four pts from group A (6.6%) and 20 pts from group B (38.5%) received antihypertensive therapy (captopril, nifedipine, furosemide and propranolol ). All children from group A and half of the children from group B had normal renal function. Eighteen pts from group B were on chronic haemodialysis (34.6%). Blood pressure was recorded during a 24-hour period except in haemodialyzed pts (48 h) (Table 1). Results of BP measurements are presented as the mean values of BP during a 24-hour period, during normal daily activities and during sleep. We used the age- and gender-appropriate 95th percentile from the Task Force Study as the daytime upper-limit of normal and 10% lower for the upper-limit at night. According to BP load (the percentage of BPs exceeding the upper limits of normal for age), children were assumed to have mild-to-moderate hypertension (BP load between 20% and 40%) or severe hypertension (BP load more than 40%). The success of antihypertensive therapy was evaluated after 1-3 months in 11 pts (twice in 10 pts and three times in one pt). RESULTS: In group A 39.4% of pts were normotensive and 36.1% were without antihypertensive therapy, 58.4% of normotensive and 40.5% of hypertensive pts had blunted circadian BP rhythm (nocturnal BP reduction of less than 10% of diurnal values) (Graph. 1). In group B 38.5% of pts were normotensive and 27% were without antihypertensive therapy. In the group of normotensive pts alteration of circadian BP rhythm was found in 40% of pts with normal renal function, 80% of pts with chronic renal failure and in 100% of pts with terminal renal failure, while in the hypertensive group, altered circadian BP rhythm had 68%, 100% and 92% of pts, respectively (Graph 2). Mild-to-moderate hypertension had 54% of hypertensive pts from group A and 37.5% of hypertensive pts from group B. Severe hypertension was more frequent in group B (62.5%) comparing to group A (46%). The effectiveness of antihypertensive therapy was assessed in 11 pts. In 69.2% of pts BP became normal or was significantly decreased, in 23.1% of pts BP was not changed and 7.7% of pts had higher values of BP. DISCUSSION: ABPM is very useful for diagnosing white coat hypertension. Like other authors, we have pointed out that more than one third of pts who were hypertensive according to usual BP measurements had normal 24-hour BP and we classified them as white coat hypertensives. More than a half of the pts had blunted circadian BP rhythm, and as it is not certain whether they will become hypertensive in adulthood they should be periodically controlled. There are several proofs that results of ABPM have a better correlation with hypertensive end-organ damage; therefore ABPM is used for assessing the severity of hypertension. In our former work, we showed excellent correlation of BP with left ventricular mass index in children with end-stage renal failure. (ABSTRACT TRUNCATED)     

Study of 24-hour changes in blood pressure in various stages of diabetic nephropathy

The aim of the study was to compare the diurnal pattern of blood pressure in diabetic patients with normal urinary protein excretion, microalbuminuria and end stage renal failure due to diabetic nephropathy and on continuous ambulatory peritoneál dialysis. An ABPM-oscillometric blood pressure monitor was used. Cholesterol, triglicerides, HDL and LDH1 cholesterole, apolipoprotein A1 and B, endogenous creatinine urinary protein and albumin excretion, beta-2-microglobulin were measured. The mean age and the mean diabetes duration of the 12 normoalbuminuric patients 38.3 and 16.5 years, of the 12 patients treated for renal failure with continuous ambulatory peritoneál dialysis 54.4 and 19.5 years. In the group with end stage renal failure and continuous ambulatory peritoneál dialysis, the mean nocturnal and diurnal systolic and diastolic blood pressure and the average arterial mean pressure was significantly higher than in the normal and microalbuminuric groups. In microalbuminuric and dialysed patients the physiological nocturnal decline of arterial blood pressure was absent. 24 hour blood pressure monitoring may accurately identify the early stage of diabetic nephropathy, and it might be valuable in the correction of antihypertensive treatment from the early to the final stages of diabetic nephropathy.     

Ambulatory pulse pressure: a potent predictor of total cardiovascular risk in hypertension

A wide pulse pressure (PP) is a marker of increased artery stiffness and high cardiovascular (CV) risk. To investigate the prognostic value of ambulatory PP, which is currently unknown, we studied 2010 initially untreated subjects with uncomplicated essential hypertension (mean age, 51.7 years; 52% men). All subjects underwent baseline procedures including 24-hour noninvasive ambulatory blood pressure (BP) monitoring. The mean duration of follow-up was 3.8 years (range, 0 to 11 years), and CV morbidity and mortality were the outcome measures. There were 200 major CV events (2.61 per 100 person-years), 36 of which were fatal (0.47 per 100 person-years). In the 3 tertiles of the distribution of office PP, the rate of total CV events (per 100 persons per year) was 1.38, 2. 12, and 4.34, respectively, and that of fatal events was 0.12, 0.30, and 1.07 (log-rank test, both P<0.01). In the 3 tertiles of the distribution of average 24-hour PP, the rate of total CV events was 1.19, 1.81, and 4.92, and that of fatal events was 0.11, 0.17, and 1. 23 (log-rank test, both P<0.01). After controlling for several independent risk markers including white coat hypertension and nondipper status, we found that ambulatory PP was associated with the biggest reduction in the -2 log likelihood statistics for CV morbidity (P<0.05 versus office PP). In each of the 3 tertiles of office PP, CV morbidity and mortality increased from the first to the third tertile of average 24-hour ambulatory PP (log-rank test, all P<0.01). Age, left ventricular hypertrophy, and nondipper status were independent predictors of CV mortality, and the further predictive effect of ambulatory PP (P<0.001) was marginally but not significantly superior to that of office PP and average 24-hour systolic BP. We conclude that ambulatory PP is a potent risk marker in essential hypertension. CV morbidity is more closely predicted by ambulatory than by office PP even after control for multiple risk factors.