Showing papers on "Ambulatory blood pressure published in 1994"

Ambulatory blood pressure. An independent predictor of prognosis in essential hypertension.

Abstract: To determine the prognostic significance of ambulatory blood pressure, we prospectively followed for up to 7.5 years (mean, 3.2) 1187 subjects with essential hypertension and 205 healthy normotensive control subjects who had baseline off-therapy 24-hour noninvasive ambulatory blood pressure monitoring. Prevalence of white coat hypertension, defined by an average daytime ambulatory blood pressure lower than 131/86 mm Hg in women and 136/87 mm Hg in men in clinically hypertensive subjects, was 19.2%. Cardiovascular morbidity, expressed as the number of combined fatal and nonfatal cardiovascular events per 100 patient-years, was 0.47 in the normotensive group, 0.49 in the white coat hypertension group, 1.79 in dippers with ambulatory hypertension, and 4.99 in nondippers with ambulatory hypertension. After adjustment for traditional risk markers for cardiovascular disease, morbidity did not differ between the normotensive and white coat hypertension groups (P = .83). Compared with the white coat hypertension group, cardiovascular morbidity increased in ambulatory hypertension in dippers (relative risk, 3.70; 95% confidence interval, 1.13 to 12.5), with a further increase of morbidity in nondippers (relative risk, 6.26; 95% confidence interval, 1.92 to 20.32). After adjustment for age, sex, diabetes, and echocardiographic left ventricular hypertrophy (relative risk versus subjects with normal left ventricular mass, 1.82; 95% confidence interval, 1.02 to 3.22), cardiovascular morbidity in ambulatory hypertension was higher (P = .0002) in nondippers than in dippers in women (relative risk, 6.79; 95% confidence interval, 2.45 to 18.82) but not in men (P = .91). Our findings suggest that ambulatory blood pressures stratifies cardiovascular risk in essential hypertension independent of clinic blood pressure and other traditional risk markers including echocardiographic left ventricular hypertrophy.(ABSTRACT TRUNCATED AT 250 WORDS)

Association between ambulatory blood pressure and alternative formulations of job strain.

Abstract: OBJECTIVES--The goal of the study was to determine whether alternative formulations of Karasek & Theorell's job-strain construct are associated with ambulatory blood pressure and the risk of hypertension. METHODS--Full-time male employees (N = 262) in eight worksites completed a casual blood pressure screening, medical examinations, and questionnaires and wore an ambulatory blood pressure monitor for 24 h on a workday. Cases of hypertension were ascertained from casual blood pressure readings for a case-referent analysis. A cross-sectional analysis was also conducted, ambulatory (continuous) blood pressure measurements being used as the outcome. RESULTS--All formulations of job strain exhibited significant associations with systolic blood pressure at work and home, but not with diastolic blood pressure. Employees experiencing job strain had a systolic blood pressure that was 6.7 mm Hg (approximately 0.89 kPa) higher and a diastolic blood pressure that was 2.7 mm Hg (approximately 0.36 kPa) higher at work than other employees, and the odds of hypertension were increased [odds ratio (OR) 2.9, 95% confidence interval (95% CI) 1.3-6.6]. Using national means for decision latitude and demands to define job strain increased the systolic and diastolic blood pressure associations to 11.5 mm Hg (approximately 1.53 kPa) and 4.1 mm Hg (approximately 0.54 kPa), respectively. Adding organizational influence to the task-level decision latitude variable produced a stronger association for hypertension with job strain (OR 3.7, 95% CI 1.6-8.5). Adding social support to the job-strain model also slightly increased the hypertension risk. CONCLUSIONS--The impact of job strain, at least on systolic blood pressure, is consistent and robust across alternative formulations, more restrictive cut points tending to produce stronger effects.

Ambulatory Blood Pressure in the Transition from Normo- to Microalbuminuria: A Longitudinal Study in IDDM Patients

Abstract: To describe the development in blood pressure (BP) in relation to urinary albumin excretion (UAE) more exactly, 44 initially normoalbuminuric type I diabetic patients and 21 healthy individuals were included in a 3.1-year follow-up study by using ambulatory BP (AMBP) monitoring. Six patients developed microalbuminuria according to accepted criteria (progressors; UAE at follow-up was > 20 micrograms/min). Initial UAE was higher in this group (9.0 x/divided by 1.4 micrograms/min) compared with both the nonprogressors (5.2 x/divided by 1.6 micrograms/min) and the control subjects (3.9 x/divided by 1.6 micrograms/min), P < 0.01. The values were almost identical for initial 24-h AMBP between the progressors and the two other groups. The transition to microalbuminuria (31.7 x/divided by 1.8 micrograms/min) was associated with an increase in 24-h systolic AMBP of 11.5 +/- 8.3 mmHg, which was significantly higher than the increase in the nonprogressors (3.1 +/- 7.7 mmHg) and the control subjects (2.2 +/- 6.1 mmHg, P = 0.02). Significant correlations were detected between development in UAE and development in systolic and diastolic 24-h AMBP (r = 0.39, r = 0.41, P < 0.01). In addition, an increase in UAE, even including increases within the normoalbuminuric range, was always associated with an increase in 24-h AMBP (P < 0.01). Ordinary clinical measurements did not reveal any of these differences or correlations. In conclusion, a close association between increases in UAE and 24-h AMBP emerges in this study. Initial BP was not increased in the progressors.(ABSTRACT TRUNCATED AT 250 WORDS)

Factors Affecting Ambulatory Blood Pressure Reproducibility Results of the HARVEST Trial

Abstract: To assess the reproducibility of ambulatory blood pressure, we recorded 24-hour blood pressure twice 3 months apart in 508 hypertensive subjects participating in the HAR- VEST trial using a noninvasive technique. Blood pressure was measured every 10 minutes during the daytime and 30 minutes during the nighttime. Reproducibility was better for ambula- tory than for office blood pressure. It was greater for 24-hour than for daytime blood pressure and lowest for nighttime blood pressure. The reproducibility of blood pressure variabil- ity (standard deviation) was poorer than that of the average values. A small but significant decrease in average daytime blood pressure (-0.8/-1.0 mm Hg) and virtually no change in nighttime blood pressure (+0.5/+0.1 mmHg) were observed at repeat recording. Reducing the sampling rate by 50% caused only a small impairment of the reproducibility indexes of both the average values and variability. Blood pressure reduction was greater during the first and last hours of the recordings, indicating an effect of the hospital environment on the between-monitoring difference. Changes in body weight (-0.7 kg, P=.006, at repeat recording) were related to those of 24-hour diastolic blood pressure (P<.05). In conclusion, pa- tient reaction to medical environment and changes of body weight seem to account for most of the change in 24-hour blood pressure that occurs over a 3-month period. (Hyperten- sion. 1994^3:211-216.) Key Wordshypertension, essentialblood pressure monitoring, ambulatoryblood pressurereproducibility of resultsclinical trialsblood pressure variability

Factors affecting ambulatory blood pressure reproducibility. Results of the HARVEST Trial. Hypertension and Ambulatory Recording Venetia Study.

Abstract: To assess the reproducibility of ambulatory blood pressure, we recorded 24-hour blood pressure twice 3 months apart in 508 hypertensive subjects participating in the HARVEST trial using a noninvasive technique. Blood pressure was measured every 10 minutes during the daytime and 30 minutes during the nighttime. Reproducibility was better for ambulatory than for office blood pressure. It was greater for 24-hour than for daytime blood pressure and lowest for nighttime blood pressure. The reproducibility of blood pressure variability (standard deviation) was poorer than that of the average values. A small but significant decrease in average daytime blood pressure (-0.8/-1.0 mm Hg) and virtually no change in nighttime blood pressure (+0.5/+0.1 mm Hg) were observed at repeat recording. Reducing the sampling rate by 50% caused only a small impairment of the reproducibility indexes of both the average values and variability. Blood pressure reduction was greater during the first and last hours of the recordings, indicating an effect of the hospital environment on the between-monitoring difference. Changes in body weight (-0.7 kg, P = .006, at repeat recording) were related to those of 24-hour diastolic blood pressure (P < .05). In conclusion, patient reaction to medical environment and changes of body weight seem to account for most of the change in 24-hour blood pressure that occurs over a 3-month period.

Ambulatory Blood Pressure and Heart Rate Responses to the Stress of Work and Caregiving in Older Women

Abstract: BACKGROUND Although the informal caregiving role is associated with a range of stressors that are both chronic and severe, little is known concerning the acute physical and psychological effects of caregiving in the natural setting. This study evaluated the hemodynamic and psychological responses of five women identified as family caregivers who also worked outside the home and five matched working noncaregivers. METHODS Subjects wore an ambulatory blood pressure monitor that recorded blood pressure and heart rate on an hourly basis throughout a one- to two-day period. They also completed hourly logs evaluating psychological, physical, and health-related variables through use of a preprogrammed pocket computer. Within- and between-group responses were compared in clinical, work, and postwork settings. RESULTS Caregivers and noncaregivers showed comparable ambulatory blood pressure levels in the clinic and work settings. However, in contrast to noncaregivers, who showed the expected decrease in blood pressure level upon leaving the work setting (p values < .03), caregivers demonstrated a significant increase in systolic blood pressure levels following work when they were in the presence of the care recipient (p < .0002). The differences observed in blood pressure responses between the two groups were similarly reflected in the patterns of affective response recorded in the work and postwork settings. CONCLUSIONS The results provide initial evidence of the acute iatrogenic effects of caregiving on physiological as well as psychological response systems.

Microalbuminuria in 411 untreated individuals with established hypertension, white coat hypertension, and normotension.

Abstract: We compared urinary albumin excretion in normotensive subjects and patients with white coat and established hypertension. The study involved prospective comparison of office blood pressure, daytime ambulatory blood pressure, and urinary albumin excretion in consecutive patients (n = 284) who were selected from general practice with newly diagnosed mild to moderate hypertension before the institution of pharmacologic antihypertensive therapy. All patients had a diastolic office blood pressure above 90 mm Hg; 173 had a consistently elevated diastolic blood pressure (established hypertension), and 111 had an average daytime ambulatory blood pressure below 90 mm Hg (white coat hypertension). A sample of 127 subjects drawn from the Danish national register served as a normotensive control group. The main outcome measure was the ratio of early morning urinary albumin to creatinine. This ratio differed significantly among the three groups, being (on a molar basis) 21 +/- 69 x 10(-6) in the normotensive subjects, 22 +/- 39 x 10(-6) in the white coat hypertensive patients, and 51 +/- 177 x 10(-6) in patients with established hypertension. The difference remained significant after correction for covariables. The ratio of early morning urinary albumin to creatinine was weakly but significantly correlated to blood pressure, was more pronounced for ambulatory than for office measurements, was more pronounced for systolic than for diastolic pressure, and was more pronounced for hypertensive than for normotensive individuals. The ratio was as reproducible a measure as 24-hour albumin excretion. We conclude that white coat hypertensive patients have less renal involvement than patients with established hypertension but more than a normotensive control group.

Ambulatory blood pressure and microalbuminuria in essential hypertension: role of circadian variability.

Abstract: ObjectiveTo assess the relationship of subclinical urinary albumin excretion with ambulatory and circadian variability of blood pressureDesign and methodsPatients with essential hypertension (82 males and 59 females, mean + SD age 389 ±73 years) who had never been previously treated for hypertens

Systemic hypertension at 4,300 m is related to sympathoadrenal activity

Abstract: Residence at high altitude has been associated with elevation in systemic arterial blood pressure, but the time course has been little studied and the mechanism is unknown. Because plasma epinephrine (E) and norepinephrine (NE) also increase at altitude, we hypothesized that heightened sympathoadrenal activity may cause increased arterial pressure. We measured ambulatory blood pressure by cuff monitor in relation to 24-h urinary excretion of E and NE at sea level and during 3 wk of residence at 4,300 m (Pikes Peak, CO) in 11 healthy men. In five subjects taking placebo, arterial pressure progressively increased at 4,300 m from 82 +/- 1 (SE) mmHg at sea level to 88 +/- 3 on day 2, 91 +/- 3 on day 8, and 97 +/- 6 on day 17. In six subjects, propranolol (240 mg/day) decreased pressure from 85 +/- 4 to 77 +/- 1 mmHg at sea level but did not prevent sustained increase in pressure at 4,300 m (84 +/- 1, 81 +/- 1, and 85 +/- 3 mmHg on days 2, 8, and 17, respectively). Compared with the placebo group, blood pressure did not increase further over the initial elevation observed on day 2 in the propranolol group. There was interindividual variability in the blood pressure responses in both groups, with some subjects demonstrating a more marked increase in blood pressure. Urinary excretion of NE increased concomitantly with pressure at altitude in both groups, with a greater rise in the placebo group.(ABSTRACT TRUNCATED AT 250 WORDS)

Relation between physical training and ambulatory blood pressure in stage I hypertensive subjects. Results of the HARVEST Trial. Hypertension and Ambulatory Recording Venetia Study.

Abstract: BACKGROUND This study was undertaken to assess whether ambulatory blood pressure (BP) in a population of stage I hypertensive individuals was lower in the subjects performing regular exercise training. METHODS AND RESULTS The study was carried out in 796 young hypertensive patients (592 men) who had never been treated who took part in the HARVEST trial. The diagnosis of stage I hypertension was made on the basis of six office BP measurements. Subjects underwent noninvasive 24-hour ambulatory BP monitoring, 24-hour urine collection for catecholamine assessment, and echocardiography (n = 457). They were classified as exercisers if they reported at least one session of aerobic sports per week and as nonexercisers if they did not engage regularly in sports activities. Age (P < .0001), body mass index (P = .002), 24-hour heart rate (P < .0001), alcohol intake (P = .02), smoking (P = .02), and norepinephrine output (P = .04) were lower in the active (n = 153) than the inactive (n = 439) men. Physically active men exhibited a lower 24-hour and daytime diastolic BP than the inactive men, while there were no group differences in office BP or in nighttime diastolic BP and in ambulatory systolic BP. The between-group ambulatory diastolic BP difference remained statistically significant after adjustment for age, body mass index, alcohol intake, and smoking (P < .0001). Of the nonexercisers, 46.2% were confirmed hypertensives, compared with only 26.8% of the exercisers (P < .0001), on the basis of daytime diastolic BP. Echocardiographic left ventricular dimensional and functional indexes were similar in the two groups of men. Similar findings were shown by the 16 women who engaged in aerobic sports. CONCLUSIONS These data suggest that participation in aerobic sports may attenuate the risk of hypertension in young subjects whose office BP is in the stage I hypertensive range at office measurement.

Nocturnal blood pressure in normotensive subjects and those with white coat, primary, and secondary hypertension

Abstract: Objective: To compare the mean nocturnal blood pressure of patients with various forms of renal and endocrine hypertension with that in patients with primary and white coat hypertension, and normal blood pressure. Design: Ambulatory monitoring of blood pressure over 24 hours in a prospective study. Setting - Two German centres for outpatients with hypertension and kidney diseases. Subjects: 176 normotensive subjects, 490 patients with primary hypertension including mild and severe forms, 42 with white coat hypertension, 208 patients with renal and renovascular hypertension, 43 with hypertension and endocrine disorders, and three with coarctation of the aorta. Main outcome measures: Fall in nocturnal blood pressure. Results - Blood pressure in normotensive subjects fell by a mean of 14 mm Hg (11%) systolic and 13 mm Hg (17%) diastolic overnight (2200 to 0600). The falls in patients with primary and white coat hypertension were not significantly different. In all patients with renal and renovascular hypertension, however, the fall was significantly reduced (range of fall from 3/3 mm Hg to 7/9 mm Hg). In patients with hypertension and endocrine disorders the pattern of night time blood pressure was not uniform: patients with hyperthyroidism, primary hyperaldosteronism, and Cushing9s syndrome had significantly smaller reductions in blood pressure (6/8, 4/7, 3/6 mm Hg, respectively). In patients with phaeochromocytoma the mean night time blood pressure increased by 4/2 mm Hg. In patients with hypertension, primary hyperparathyroidism, and unoperated coarctation of the aorta the falls in blood pressure were normal. Conclusions: In normotensive subjects and those with primary hypertension there is usually a reduction in blood pressure at night. In all renal forms of secondary hypertension and in most endocrine forms the reduction in blood pressure is only a third to a half of normal. Patients with primary hyperparathyroidism and unoperated coarctation of the aorta show a normal reduction.

Ambulatory blood pressure in normotensive and hypertensive subjects: results from an international database.

Abstract: Objective: To delineate more precisely an operational threshold for making clinical decisions based on ambulatory blood pressure (ABP) measurement by studying the ABP in subjects who were diagnosed as either normotensive or hypertensive by conventional blood pressure (CBP) measurement. Subjects: Twenty-four research groups recruited 7069 subjects. Of these, 4577 were normotensive (CBP 160 mmHg) and 1310 had diastolic hypertension (diastolic CBP >95 mmHg). Combined systolic and diastolic hypertension was present in 861 subjects. Hypertension had been diagnosed from the mean of two to nine (median two) CBP measurements obtained at one to three (median two) visits. Results: The 95th centiles of the ABP distributions in the normotensive subjects were (systolic and diastolic, respectively) 133 and 82 mmHg for 24-h ABP, 140 and 88 mmHg for daytime ABP and 125 and 76 mmHg for night-time ABP, respectively. Of the subjects with systolic hypertension, 24% had 24-h systolic ABP

Long-term reproducibility of ambulatory blood pressure.

Abstract: ObjectiveTo compare the reproducibility of ambulatory and office blood pressure readings in established hypertensive subjects when studies are repeated at extended time intervals.SubjectsTwenty-five hypertensive patients (office diastolic blood pressure ≥90mmHg) who were off antihypertensive therapy

Diagnosis of mild hypertension by ambulatory blood pressure monitoring.

Abstract: BACKGROUND Between 20% and 30% of patients with clinically diagnosed hypertension have normal blood pressure (BP) values during automated ambulatory 24-hour BP monitoring. It has not been clear, however, whether these patients can be regarded as normotensive or whether they should be treated in the same way as confirmed hypertensive patients. METHODS AND RESULTS Ambulatory BP monitoring was performed in 88 normal control subjects and 171 hypertensive patients (office diastolic BP > or = 90 mm Hg on three visits; never treated or off treatment for more than 6 months). Hypertensive patients were classified as nonconfirmed or white coat (n = 58) if their 24-hour diastolic averages were < 85 mm Hg and at least 15 mm Hg lower than their office values. For comparisons, white coat patients were pair-matched with normal subjects by 24-hour diastolic averages and sex, and by similar age and weight; there were 40 such pairs. White coat patients were likewise pair-matched with confirmed hypertensive patients by identical office BPs (51 pairs). Participants were studied by individualized treadmill testing, Doppler echocardiography, and assays of resting plasma catecholamines, upright plasma renin and aldosterone, and lipid, glucose, and insulin concentrations. Because of the matching, compared with normal subjects, patients with white coat hypertension and normal subjects had identical 24-hour BP averages. The white coat patients exhibited slightly greater variability among individual readings (obtained each 15 minutes) throughout the day [P < .05]), but there were no differences in hemodynamic responses to exercise. Plasma norepinephrine (P < .05), renin and aldosterone (P < .01 for each), and insulin and low-density lipoprotein cholesterol levels (P < .01 for each) were higher in the white coat group, as were left ventricular septal wall (P < .05) and muscle mass (P = .07) echocardiographic measurements. When compared with the confirmed hypertensive patients, the white coat patients had higher renin (P < .01) but were otherwise similar. Within the white coat group, plasma norepinephrine correlated with total cholesterol and triglycerides (P < .05 for each), and aldosterone correlated with left ventricular mass (P < .01); there were no significant correlations within the normal control subject or confirmed hypertension groups. CONCLUSIONS Patients with white coat hypertension differ in metabolic, neuroendocrine, and cardiac findings from normal control subjects and have greater BP variability. These changes appear to be mediated by heightened activity of the sympathetic and renin-angiotensin systems. Although these characteristics could reflect an alerting reaction in the clinic due to awareness of their diagnosis, the white coat hypertensive patients also have evidence for additional, more-sustained differences from normal subjects. Thus, this condition appears to be a true variant of hypertension.

Ambulatory blood pressure and prognosis.

Abstract: PROGNOSTIC INFORMATION: Ambulatory blood pressure monitoring provides three kinds of information, all of which might have prognostic significance: blood pressure level, amplitude of diurnal variation and short-term variability. BLOOD PRESSURE LEVEL: Existing data support the hypothesis that patients whose ambulatory blood pressure is low in comparison with clinic blood pressure (white-coat hypertension) have a relatively low risk of morbidity. AMPLITUDE OF DIURNAL RHYTHM OF BLOOD PRESSURE: While there is limited support for the hypothesis that patients with small diurnal variations may carry a higher risk (particularly women), opposing hypotheses are also plausible. SHORT-TERM BLOOD PRESSURE VARIABILITY: It is hypothesized that increased variability will be associated with increased morbidity. Preliminary data from the Cornell prospective study are consistent with this hypothesis.

Ambulatory blood pressure monitoring in normotensive children.

Abstract: OBJECTIVE To assess reference values of ambulatory blood pressure in normotensive children. SUBJECTS AND DESIGN Twenty-four-hour non-invasive ambulatory blood pressure monitoring (ABPM) was carried out in 241 healthy normotensive children aged from 6 to 16 years (126 boys, mean +/- SD age 11.2 +/- 2.7 years; 115 girls, mean +/- SD age 10.9 +/- 2.9 years). The subjects were subdivided into three age-sex groups: 6-9, 10-12 and 13-16 years. SETTING Primary care. MAIN OUTCOME MEASURES ABPM was performed using an oscillometric device (SpaceLabs model 90207) and appropriate cuff size during a regular school day. Blood pressure was measured every 20 min from 0600 to 2400 h, and thereafter every 30 min. At each monitoring session the following parameters were calculated for both systolic (SBP) and diastolic blood pressure (DBP): means and centiles for 24-h, daytime (0800-2200 h) and night-time (2400-0600 h); circadian variability, estimated as the blood pressure fall between the day and the night periods and the day: night ratio; and load, as the percentage of measurements above the age- and sex-specific 95th centile (P95). RESULTS The upper limits of 'normality' for the mean of 24-h SBP and DBP estimated as the P95 in each age subgroup were 121/71 and 119/71 mmHg, 123/78 and 120/74 mmHg, and 124/78 and 125/75 mmHg, for boys and girls, respectively. A progressive increase in SBP with age was observed in both sexes, in contrast, DBP was similar throughout the age range. A nocturnal blood pressure fall of approximately 11 mmHg was observed for both SBP and DBP in all subgroups. The day:night ratio was 1.12 and 1.22 for SBP and DBP, respectively. The upper limit of blood pressure load, estimated as the P95 in all children, was 39% for SBP and 26% for DBP. A significant positive correlation was observed between casual blood pressure and 24-h ambulatory blood pressure (SBP: r = 0.61, P < 0.0001; DBP: r = 0.31, P < 0.0001). In general, mean ambulatory blood pressure, during the 24-h or the daytime period, was higher than casual blood pressure for both SBP and DBP. CONCLUSION ABPM is feasible in children, and the values obtained are useful as a departure point in establishing reference values.

Effect of measuring ambulatory blood pressure on sleep and on blood pressure during sleep.

Abstract: Objective: To assess whether recording of ambulatory blood pressure at night causes arousal from sleep and a change in the continuous blood pressure recorded simultaneously. Design: Repeated measurement of blood pressure with two ambulatory blood pressure machines (Oxford Medical ABP and AD the size of any changes that this arousal and change in blood pressure produced in the blood pressure recorded by the ambulatory machine. Results: Both ambulatory blood pressure machines caused arousal from sleep: the mean duration of arousal was 16 seconds (95% range 0-202) with the ABP and 8 seconds (0-73) with the TM2420. Both also caused a rise in beat to beat blood pressure. During non-rapid eye movement sleep, this rise led to the ABP machine overestimating the true systolic blood pressure during sleep by a mean of 10 (SD 14.8) mm Hg and the TM2420 by a mean of 6.3 (8.2) mm Hg. On average, diastolic pressure was not changed, but measurements in individual subjects changed by up to 23 mm Hg. These changes varied in size among subjects and stages of sleep and were seen after measurements that did not cause any electroencephalographic arousal. Conclusions: Ambulatory blood pressure machines cause appreciable arousal from sleep and therefore alter the blood pressure that they are trying to record. This effect should be taken into account when recordings of blood pressure at night are interpreted in clinical work and epidemiological research.

"Non-dipping" related to cardiovascular events in essential hypertensive patients.

Abstract: About 1 third of all patients with essential hypertension reveal an impaired circadian pattern of blood pressure. This phenomenon called "non-dipping" (i.e. a lack of the normal nocturnal fall in blood pressure) is related to a higher incidence of end-organ damage such as left ventricular hypertrophy. It is the purpose of this study to evaluate, whether or not non-dipping of blood pressure may worsen the prognosis of hypertensive subjects. 116 consecutive hypertensives underwent an ambulatory blood pressure monitoring (ABPM) using the Spacelabs 2000 device. 2 groups were established: Group I (n = 87) were "dippers", group II (n = 29) "non-dippers" showing a diminished or even lack of nocturnal fall in blood pressure. No difference was seen concerning sex, mean 24-hour systolic blood pressure, systolic and diastolic causal blood pressure and heart rate. However, a significant difference in age and mean 24-hour diastolic blood pressure could be observed. In a follow-up investigation after approximately 31 months all patients and/or their physicians were contacted concerning cardiovascular events during the time since the ABPM was performed. In Group I only 1 transient ischemic attack occurred, but in group II 4 patients showed major cardiovascular events: 3 deaths occurred (2 of which caused by myocardial infarction, 1 by apoplexy), while 1 suffered from a transient ischemic attack (p < 0.001). Thus, in essential hypertension non-dipping of blood pressure is associated with an increased occurrence of cardiovascular events, and, therefore, the circadian blood pressure profile should be carefully monitored.

Elevated serum insulin levels in patients with essential hypertension and microalbuminuria.

Abstract: Hyperinsulinemia, insulin resistance, or both have been described in patients with essential hypertension. Previous work from our laboratory has shown that in hypertensive patients with microalbuminuria, dyslipidemia and abnormal patterns in the diurnal variations of blood pressure are frequently associated. Whether hyperinsulinemia and microalbuminuria are directly related has not been determined. To test this possibility, we measured the plasma insulin response to an oral glucose load in 25 patients with or without microalbuminuria and 20 normotensive control subjects. Serum lipid profile and 24-hour ambulatory blood pressure were obtained. In the hypertensive patients as a group, the plasma insulin response to glucose (evaluated as the insulin area under the curve) was significantly enhanced compared with a group of 20 normotensive healthy control subjects (46,311 +/- 3745 and 27,557 +/- 2563 pmol/L x 2 hours, P < .01). When the hypertensive patients were subdivided according to their albumin excretion rate, the microalbuminuric patients had significantly higher plasma glucose (969 +/- 45.2 versus 762 +/- 28.7 mmol/L x 2 hours, P < .01) and insulin (59,172 +/- 5964 versus 37,737 +/- 3422 pmol/L x 2 hours, P < .01) area under the curve values. In addition, a significant direct correlation was found to exist between insulin area under the curve and the urinary albumin excretion rate (r = .63, P < .001). Serum levels of lipoprotein(a) were significantly greater (P < .01) in patients with than in those without microalbuminuria and in control subjects. Furthermore, daytime diastolic blood pressure and nighttime systolic and diastolic blood pressure values were greater in patients with than in those without microalbuminuria.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood pressure variability and organ damage.

Abstract: Several studies have now shown that hypertension-induced end-organ damage is more closely related to 24-h average blood pressure than to clinic measurements. Furthermore, the degree of variability of blood pressure during a 24-h period bears a relation to organ damage that is independent of average blood pressure value. The measurement of blood pressure variability is a complex task, however, because data from automatic ambulatory blood pressure monitoring should be interpreted with caution, especially if the interval between blood pressure measurements is more than 15 min, and different types of blood pressure variability (e.g., short-term and long-term) can make calculation of variability by standard deviation of 24-h blood pressure values difficult, which further complicates measurement procedures and interpretation. Evidence is growing to suggest that blood pressure variability in hypertension is clinically significant. We have recently shown that over a 7.5-year period, end-organ damage is independently related to the initial blood pressure variability. Although information on the effect of antihypertensive treatment on 24-h blood pressure variability is limited, the available data suggest more of an effect on 24-h average blood pressure levels than on 24-h blood pressure changes. Further studies should investigate treatment effects on different types of blood pressure variability and the impact of treatment on patient protection and prognosis.

Ambulatory blood pressure and left ventricular hypertrophy in subjects with untreated obstructive sleep apnoea and snoring, compared with matched control subjects, and their response to treatment.

Abstract: 1. Obstructive sleep apnoea and snoring are associated with daytime hypertension. It is uncertain whether this association is directly due to the disturbed sleeping respiration or the result of confounding variables, particularly obesity, smoking and alcohol intake. 2. Ambulatory blood pressure and echocardiographic left ventricular muscle mass were measured in 19 patients with obstructive sleep apnoea, 19 men who snore without apnoea and 38 control subjects matched for age, sex, body mass index, smoking and alcohol intake. Ambulatory blood pressure was also measured before and after treatment in 11 patients with obstructive sleep apnoea and their matched control subjects. 3. Compared with matched control subjects, untreated obstructive sleep apnoea and snoring were not associated with an increase in daytime blood pressure. A daytime elevation of either systolic or diastolic blood pressure of > 3.8 mmHg due to obstructive sleep apnoea or snoring was excluded with 95% confidence in each of the study groups. Daytime blood pressure was also unchanged when obstructive sleep apnoea was treated with nasal continuous positive airway pressure. Night-time blood pressure was not significantly different in the patients with obstructive sleep apnoea or the snorers when compared with their matched control subjects. However, a fall in night-time systolic blood pressure was seen in the patients with obstructive sleep apnoea after treatment [fall in systolic blood pressure -6.3 (SD 8.2) mmHg, P < 0.02]. 4. Left ventricular diameter, wall thickness and calculated mass were similar in each of the study groups and their matched control groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Negative affect, gender, and expressive style predict elevated ambulatory blood pressure in adolescents.

Abstract: Excessive blood pressure elevations during daily activities increase cardiovascular risk and may be related to individual differences in emotionality and expressive style. Emotional traits and ambulatory blood pressure were measured during a typical school day in 228 Black and White adolescents at risk of developing essential hypertension. Trait affect (depression, anger) predicted prevailing blood pressure levels; this association was moderated by gender, social setting (in classroom vs. with friends), and nonverbal expressive style. Relationships between emotion and blood pressure were not explained by obesity, smoking, or alcohol use. The uniform environment and regimen of the school made it possible to attribute variations in prevailing blood pressure to personality differences involving ways adolescents perceive and negotiate their social world.