The difference between clinical ambulatory measured blood pressure and daily monitored pressure does not reflect the "white coat effect"

The difference between clinic and average daytime ambulatory blood pressure is frequently used to identify patients with "white coat" hypertension (i.e. with a pronounced pressor response to the clinical evaluation) although there is no evidence that this difference is indeed due to a white coat effect. In 28 mild hypertensive outpatients, the blood pressure was continuously recorded by a noninvasive finger device before and during the doctor's visit. The peak blood pressure increase, recorded during the visit was compared with the difference between clinic and daytime average ambulatory blood pressure. Peak increases in systolic and diastolic finger blood pressure during the doctor's visit were 38.2 +/- 3.1 mmHg and 20.7 +/- 1.6 mmHg, respectively compared to pre visit values (means +/- standard error, both p < 0.01). Daytime average systolic and diastolic blood pressure were 135.5 +/- 2.5 mmHg and 89.2 +/- 1.9 mmHg, both being lower than the corresponding clinic blood pressure values (146.6 +/- 3.6 mmHg and 94.9 +/- 2.2 mmHg, p < 0.01). Their differences, however, were < 30% of the peak finger blood pressure increase during the physician's visit. While the physician's visit was associated with tachycardia (+9.0 +/- 1.6 b/min, p < 0.01) there was no difference between clinic and daytime average heart rate. The alerting reaction and the pressor response induced by the physician's visit is not reflected by the difference between clinic and daytime average blood pressure. Such a difference is not therefore a reliable measure of the white coat effect.     

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.     

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.     

Office and ambulatory blood pressure in patients with craniomandibular disorders

To assess the physiologic response to daily life stress in patients with craniomandibular disorders (CMD), office and ambulatory blood pressure and heart rate were studied in 25 female patients and 25 controls. Significant differences (p < 0.05) were found between the groups for heart rate before the clinical examination and that in the patient group when compared before and after the clinical examination. Higher values were found for mean daytime systolic and diastolic blood pressure in the control group compared with the patient group (p < 0.05). The mean number of systolic blood pressure > or = 140 mmHg during 24 h and daytime was significantly higher (p < 0.05) in the control group than in the patient group. In this study the CMD patients with muscular diagnosis were not more stressed than healthy subjects in the daily activities as evaluated by ambulatory blood pressure measurements.     

Changes in left ventricular structure and function in patients with white coat hypertension: cross sectional survey

OBJECTIVES: To assess the relation between white coat hypertension and alterations of left ventricular structure and function. DESIGN: Cross sectional survey. SETTING: Augsburg, Germany. SUBJECTS: 1677 subjects, aged 25 to 74 years, who participated in an echocardiographic substudy of the monitoring of trends and determinants in cardiovascular disease Augsburg study during 1994-5. OUTCOME MEASURES: Blood pressure measurements and M mode, two dimensional, and Doppler echocardiography. After at least 30 minutes' rest blood pressure was measured three times by a technician, and once by a physician after echocardiography. Subjects were classified as normotensive (technician <140/90 mm Hg, physician <160/95 mm Hg; n=849), white coat hypertensive (technician <140/90 mm Hg, physician >=160/95 mm Hg; n=160), mildly hypertensive (technician >=140/90 mm Hg, physician <160/95 mm Hg; n=129), and sustained hypertensive (taking antihypertensive drugs or blood pressure measured by a technician >=140/90 mm Hg, and physician >=160/95 mm Hg; n=538). RESULTS: White coat hypertension was more common in men than women (10.9% versus 8.2% respectively) and positively related to age and body mass index. After adjustment for these variables, white coat hypertension was associated with an increase in left ventricular mass and an increased prevalence of left ventricular hypertrophy (odds ratio 1.9, 95% confidence interval 1.2 to 3.2; P=0.009) compared with normotensive patients. The increase in left ventricular mass was secondary to significantly increased septal and posterior wall thicknesses whereas end diastolic diameters were similar in both groups with white coat hypertension or normotension. Additionally, the systolic white coat effect (difference between blood pressures recorded by a technician and physician) was associated with increased left ventricular mass and increased prevalence of left ventricular hypertrophy (P<0.05 each). Values for systolic left ventricular function (M mode fractional shortening) were above normal in subjects with white coat hypertension whereas diastolic filling and left atrial size were similar to those in normotension. CONCLUSION: About 10% of the general population show exaggerated inotropic and blood pressure responses when mildly stressed. This is associated with an increased risk of left ventricular hypertrophy.     

Factors affecting the nocturnal decrease in blood pressure: a community-based study in Ohasama

OBJECTIVE: To investigate factors affecting the nocturnal decrease in blood pressure. DESIGN: A cross-sectional study of 823 community-based untreated subjects aged > 20 years. Screening and ambulatory blood pressures were measured and the effects of age and the ambulatory blood pressure on the nocturnal decrease were examined. RESULTS: The magnitude of the decrease and the percentage decrease in the nocturnal blood pressure increased with increasing daytime ambulatory blood pressure and decreased with increasing night-time ambulatory blood pressure. Although the magnitude of the nocturnal decrease in blood pressure increased with increasing daytime blood pressure, the nocturnal blood pressure levels in hypertensives were still higher than those in normotensive subjects. The magnitude decreased with increasing age for men but not for women, whereas the percentage decrease decreased with increasing age both for men and for women. The SD of the 24 h blood pressure correlated strongly to the magnitude of the nocturnal decrease (systolic blood pressure r = 0.62, P < 0.0001; diastolic blood pressure r = 0.52, P < 0.0001), suggesting that the SD of the 24 h blood pressure is representative of the nocturnal decrease. A minimal nocturnal decrease was observed frequently in elderly normotensive men but infrequently in hypertensive individuals from the general population. A marked nocturnal decrease was observed frequently in hypertensive women aged > 70 years. CONCLUSION: Although the magnitude of the nocturnal decrease in blood pressure increased with increasing daytime blood pressure, the nocturnal blood pressure levels increased with increasing daytime ambulatory blood pressure. Therefore, the blood pressure in hypertensive subjects should essentially be lowered throughout the 24 h period. A marked nocturnal decrease in blood pressure in some elderly hypertensive women was observed without treatment. The nocturnal blood pressure levels of such subjects should be considered during treatment.     

Assessment of the nutritional state of dialysis patients

Obstructive sleep apnea syndrome (OSAS) has been associated with a higher than normal cardiovascular morbidity and mortality. Some OSAS patients lack the sleep-related, nocturnal decrease, or "dip," in blood pressure which is seen in normal individuals. These subjects, called "non-dippers," may be at greater risk for cardiovascular problems. We studied 40 OSAS patients (including 3 women) and 6 control subjects, all identified by polysomnography, for nocturnal blood pressure "dipping." We performed a second nocturnal polysomnogram to determine their apnea and hypopnea indices, (A + H)I, and oxygen saturation levels at the beginning of the study and then initiated 48 hours of ambulatory blood pressure monitoring, with data points collected every 30 minutes. Controls, which included one hypertensive subject, were all dippers. Nineteen OSAS subjects (48% of OSAS individuals) were systolic non-dippers and only 9 of them (22.5%) were diastolic non-dippers. We considered the following clinical variables as potential predictors of non-dipping: age, body mass index, respiratory disturbance index, years of reported loud snoring by bed partners, lowest oxygen saturation during nocturnal sleep, and percentage of sleep time spent with oxygen saturation below 90%. Multiple regression analyses indicated respiratory disturbance index as the only significant variable for systolic (p = 0.04) and diastolic (p = 0.03) blood pressure non-dipping. When we forced the following two nonsignificant variables into the model, they showed a very meager impact: number of years with reported loud snoring (p = 0.4 and p = 0.5, respectively for systolic and diastolic blood pressure non-dipping) and age (p = 0.5 and p = 0.6). The calculated model explained only a low percentage of the variance with an r2 of 0.25 and 0.26 for systolic and diastolic blood pressure non-dipping, respectively. Analysis of hypertension/normotension and dipping/non-dipping failed to show a significant relationship in the studied population. Fifty percent of the normotensive OSAS subjects were non-dippers and 43% of the hypertensive OSAS subjects were also non-dippers. We found a relationship between increasing respiratory disturbance index and increasing average 24-hour systolic blood pressure only when OSAS subjects were non-dippers and hypertensive.     

Twenty-four-hour ambulatory oxygen desaturation and electrocardiographic recording in obstructive sleep apnea syndrome

BACKGROUND: Although nocturnal pulseoximetry is routinely performed in obstructive sleep apnea syndrome (OSAS), pulseoximetry over a 24-h period has not been studied. HYPOTHESIS: The purpose of the study was to determine whether simultaneous 24-h oxygen desaturation and electrocardiographic (ECG) recording might be used to screen for daytime sleep sequelae in patients with OSAS. METHODS: Simultaneous recording of arterial oxygen saturation (SpO2) and ECG was conducted over a 24-h period in 18 male patients with OSAS (mean age 51.3 years) who were diagnosed by standard polysomnography (PSG), and in 15 age-matched healthy subjects (mean age 52.7 years) as controls to evaluate circadian variation of these parameters. The measures of heart rate variability (HRV) were calculated from 24-h ambulatory ECGs. Seventeen patients with OSAS showed excessive daytime sleepiness (EDS). We calculated the duration in which SpO2 decreased to < 90% (duration of SpO2 < 90%). The number of apnea/hypopneas per hour (AHI) during sleep was investigated with Apnomonitors (Chest MI, Co., Tokyo) on the same day as the SpO2 recordings. RESULTS: Controls showed no episodes of oxygen desaturation. In patients with OSAS, driving (33.3% of patients with OSAS) was the most common activity in which SpO2 decreased to < 90%, followed by daytime napping (27.8%) and resting after meals (22.2%). The duration of SpO2 < 90% over a 24-h period correlated significantly with the duration levels recorded during sleep (r = 0.99, p < 0.05) and in the afternoon (r = 0.62, p < 0.05), and with the AHI (r = 0.55, p < 0.05), but not with the duration of SpO2 < 90% in the morning. The number of ventricular premature beats correlated significantly with the duration of SpO2 < 90% for a 24-h period, but not with measures of HRV. Ventricular tachycardia was found in two (11.1%) and ST-T depression in three patients (16.6%) with underlying cardiac diseases. CONCLUSION: Our results suggest that daytime sleep attacks accompanied by oxygen desaturation in patients with moderate to severe OSAS may contribute to the occurrence of traffic or cardiovascular accidents. We conclude that 24-h ambulatory recordings of SpO2 and ECG are useful for screening for daytime sleep sequelae associated with the potential risk of this pathology in OSAS during social activities.     

Antihypertensive effects of combined lisinopril and hydrochlorothiazide in elderly patients with systodiastolic or systolic hypertension: results of a multicenter trial

This study was aimed at evaluating the antihypertensive effect of lisinopril and hydrochlorothiazide administered in the fixed combination of 20 and 12.5 mg, respectively, on clinic and 24-h blood pressure in elderly patients (age, 68.8 +/- 5.8 years, mean +/- SD) with mild-to-moderate essential systodiastolic or isolated systolic hypertension. After a washout period of 4 weeks, patients received once daily lisinopril combined with hydrochlorothiazide for a 6-week period. At the end of the washout and treatment periods, clinic blood pressure was assessed 24 h after dosing, and 24-h ambulatory blood pressure was monitored, taking blood pressure readings every 15 min. Pretreatment clinic blood pressure was 171.3 +/- 14.0/103.7 +/- 5.1 mm Hg (systolic/diastolic) in the group with systodiastolic hypertension (n = 405) and 179.6 +/- 9.4/83.6 +/- 5.4 mm Hg in the group with isolated systolic hypertension (n = 165). The corresponding 24-h average blood pressures were 144.1 +/- 13.9/88.7 +/- 8.4 mm Hg (n = 114) and 150.7 +/- 15.5/80.8 +/- 9.4 mm Hg (n = 40). Clinic blood pressure was significantly reduced by treatment in both groups. This was the case also for ambulatory blood pressure, which was reduced by 9.6 +/- 0.9%/9.9 +/- 0.9% in systodiastolic and by 11.8 +/- 1.3%/8.5 +/- 1.5% in isolated patients with systolic hypertension (p < 0.05 at least for all differences). The antihypertensive effect was similar in patients older and younger than 70 years. In all groups, it was manifest both during the day and the nighttime and was still significant after 24 h. Thus single daily administration of combined lisinopril-hydrochlorothiazide effectively reduces blood pressure in elderly patients with hypertension.     

Centralized i.v. team provides inpatient and home-care treatment

AIM: The study of the effects of the inhibitor of angiotensin converting enzyme ramipril (tritace) on the 24-h profile of blood pressure (BP) in patients with mild and moderate arterial hypertension. MATERIALS AND METHODS: Ramipril was given to 21 males aged 45-68 years with essential hypertension stage II (WHO criteria) with stable elevated diastolic blood pressure (95-114 mm Hg) in a single dose 2.5-10 mg/day. Captopril controls received 100 mg twice a day. BP was monitored using "SpaceLabs Medical" unit (model 90207, USA). RESULTS: Compared to placebo, ramipril lowered systolic and diastolic blood pressure both for the 24-h period and in the day time; captopril lowered only diastolic BP in the day time. Side effects of long-term application of ramipril occurred 2 times less frequently than in application of captopril. CONCLUSION: Long-term treatment with ramipril in the above regimen provides more effective control of BP than captopril in the above doses in patients with mild and moderate hypertension.     

Protective effect of GTS-21, a novel nicotinic receptor agonist, on delayed neuronal death induced by ischemia in gerbils

BACKGROUND: The difference between clinic and ambulatory average daytime blood pressures is frequently taken as a surrogate measure of the 'white-coat effect' (i.e. the pressor reaction triggered in the patient by the physician's visit). OBJECTIVE: To assess the reproducibility of this difference and its relationship with clinic and average ambulatory daytime blood pressure levels. DESIGN AND METHODS: These issues were addressed with two large groups of subjects in whom both clinic and ambulatory blood pressures were measured, namely 783 outpatients with systolic and diastolic essential hypertension [Group 1, aged 50.8+/-9.4 years (mean +/- SD)], participating in standardized Italian trials of antihypertensive drugs, and 506 elderly patients (group 2, age 71+/-7 years) with isolated systolic hypertension, participating in the European Syst-Eur trial. RESULTS: The clinic-daytime blood pressure difference for the essential systolic and diastolic hypertensive patients (group 1) was 13.6+/-14.3 mmHg for systolic and 9.1+/-8.6 mmHg for diastolic blood pressure (P always < 0.01). This difference for the elderly patients with isolated systolic hypertension (group 2) was 21.2+/-16.0 mmHg for systolic and only 1.3+/-10.2 mmHg for diastolic blood pressure (P < 0.01 and P < 0.05, respectively). In both studies little or no systematic clinic-daytime difference could be observed for heart rate. The reproducibility of the clinic-daytime blood pressure difference, tested for 108 essential systolic and diastolic hypertensive patients from group 1 and 128 isolated systolic hypertensives from group 2, was invariably lower than that both of daytime and of clinic blood pressure values. Finally, the clinic-daytime blood pressure difference was progressively higher for increasing levels of clinic blood pressure and progressively lower for higher levels of ambulatory daytime blood pressure. CONCLUSIONS: Thus, the clinic-daytime blood pressure difference has a limited reproducibility; depends not only on clinic but also on daytime average blood pressure, which means that its size is a function of the blood pressure criteria employed for selection of the patients in a trial; and is never associated with a systematic clinic-daytime difference in heart rate, which further questions its use as a reliable surrogate measure of the true pressor response induced in the patient by the doctor's visit.     

Activation of amylin gene transcription by LIM domain homeobox gene isl-1

The main objective of the Ambulatory Blood Pressure and Treatment of Hypertension (APTH) trial is to test the hypothesis that antihypertensive treatment based on ambulatory monitoring may be more beneficial than treatment guided by conventional sphygmomanometry. After a 2-month run-in period on single-blind placebo, hypertensive patients were randomized to two groups, one in which the target pressure was a sitting diastolic pressure from 80 through 89 mm Hg on conventional sphygmomanometry (conventional blood pressure [CBP] group), and one in which a daytime (from 10 to 20 h) diastolic pressure from 80 through 89 mm Hg had to be achieved (ambulatory blood pressure [ABP] group). After randomization all patients were started on lisinopril 10 mg/day. One month later lisinopril could be continued at 10 or 20 mg/day or discontinued depending on the attained blood pressure level. This article is an interim report on 207 patients followed for two months into the trial. At one month lisinopril was discontinued more frequently in the ABP than the CBP group (24 vs 9 patients, p = 0.004). Nevertheless at two months, blood pressure control was not significantly different in the two treatment groups. The baseline-adjusted differences in systolic pressure between the two treatment arms of the trial (ABP-CBP group) were +2.7 mm Hg (95% confidence interval [CI]): -2.9, +8.3) for the conventional pressure, +0.4 mm Hg (CI: -4.3, +5.1) for the 24 h pressure, -0.1 mm Hg (CI: -5.1, +4.8) for the daytime pressure and -0.7 mm Hg (CI: -6.7, +5.4) for the night-time pressure. The corresponding differences in diastolic pressure were -1.3 mm Hg (CI: -4, +1.4), +0.1 mm Hg (CI: -3, +3.1), -1.1 mmgH (CI: -4.4, +2.1) and +0.3 mm Hg (CI: -3.7, +4.3), respectively. Thus, the present findings do not refute the APTH research hypothesis. In terms of blood pressure control and the number of patients remaining on antihypertensive drugs, treatment based on ambulatory recordings may be preferable to treatment guided by conventional sphygmomanometry.     

The use of ambulatory pressure monitoring for evaluating antihypertensive treatment in clinical practice

OBJECTIVE: To describe the clinical experience of our Centre in the assessment of antihypertensive therapy with 24-hour ambulatory blood pressure monitoring (ABPM). DESIGN AND PATIENTS: We retrospectively studied all the 241 out-patients on antihypertensive therapy submitted to ABPM (SpaceLabs 90207, USA) between March 1992 and March 1993 for clinical purposes. We evaluated: 1) the clinical indications for the test; 2) the modifications of drug treatment suggested by the ABPM results; 3) the referring physicians' acceptance of these suggestions; 4) the changes of office BP measured before and 3-6 months after ABPM. RESULTS: 1) The indications for ABPM were: resistant or poorly controlled hypertension (n = 170-71%); suspected "white coat effect" (n = 51-21%); assessment of symptoms (n = 20-8%). 2) The analysis of ABPM suggested to modify drug treatment in 51% of the patients; a "white-coat effect" was found in 18% of the patients. 3) The ABPM suggestions about treatment were accepted by the referring physicians in 89% of the patients. 4) Office BP decreased from 163 +/- 18/99 +/- 9 mm Hg (before ABPM) to 151 +/- 13/91 +/- 7 (3-6 months after ABPM), (p < 0.001). CONCLUSIONS: The use of ABPM in our Centre, which is based on specific clinical indications, provided indications to modify the drug treatment in a high percentage of patients.     

Association between blood pressure and circulating hormonal factors with left ventricular mass in patients with essential hypertension older than 55 years of age

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

A case of acute massive pulmonary thromboembolism treated by mechanical clot fragmentation using a percutaneous transluminal angioplasty balloon

PURPOSE: Microalbuminuria predicts early mortality in non-insulin-dependent-diabetes mellitus patients (NIDDM). Our objective in the present study was to compare and assess the relationship between 24-hour, day and nocturnal ambulatory blood pressure (BP) and urinary albumin excretion rate (UAE) in microalbuminuric and normoalbuminuric NIDDM and in normal control subjects. PATIENTS AND METHODS: In the present cross-sectional study, 24 hour ambulatory BP (daytime BP and nocturnal BP) and HbA1c were compared in microalbuminuric (n = 10) and nonmicroalbuminuric NIDDM patients (n = 10) and in nondiabetic controls (n = 9). None of the patients were taking antihypertensive agents. RESULTS: In the microlbuminuric group, whereas 24 hour and daytime systolic BP differed significantly from control values (P < 0.025 and P < 0.05 respectively), there was no difference between diabetic groups. However, nocturnal systolic BP in the microalbuminuric group was significantly higher than in the normoalbuminuric diabetic patients (139 vs. 125) (P < 0.05) and a significant difference was also found between the NIDDM patients and the control group (139, 125 vs. 114) (P < 0.025). In multiple regression analysis, only nocturnal systolic BP showed a significant relationship with UAE (P < 0.05). CONCLUSIONS: We suggest that the higher nocturnal systolic blood pressure seen in our microalbuminuric NIDDM patients may contribute to the increased morbidity in this group.     

Circadian blood pressure changes in untreated children with kidney disease and conserved renal function

Ambulatory blood pressure monitoring over 24 h was applied in 31 children with kidney disease, aged 3-19 (median 11) years, in the absence of renal insufficiency and without antihypertensive therapy. Median creatinine clearance was 112 ml/min/1.73m2. Ambulatory blood pressure monitoring revealed that eight patients (26%) were hypertensive during the daytime, compared to 62% through casual recordings obtained in the office and 38% when blood pressure was taken at home. Nocturnal hypertension was detected by ambulatory monitoring in six patients, two of whom had normal blood pressure in the daytime. Median nocturnal dipping was 13% for systolic and 21% for diastolic blood pressure, i.e. similar to healthy children. Rhythm analysis recognized a distorted circadian pattern for systolic and/or diastolic blood pressure in eight patients. In conclusion, ambulatory blood pressure monitoring allows the evaluation of hypertension more reliably than casual recordings in the office. Nocturnal hypertension, as a major risk factor for renal deterioration, is detected in a similar proportion as daytime hypertension in almost 20% of untreated children with kidney disease and normal renal function.     

Ambulatory systolic blood pressure patterns in elderly hypertensives

In a recent study we found that patients with isolated systolic hypertension (ISH) had two patterns of systolic blood pressure (SBP) elevations by ambulatory BP monitoring (ABPM), sustained (S) and intermittent (I), the prognostic significance of which seems to be different. In the present study we tried to determine whether such patterns of SBP elevations may be detected among other hypertensives as well. Twenty-eight elderly patients (mean age 65.5+/-5.1 years), nine with ISH, 10 with systolodiastolic hypertension (SDH), and nine with white coat hypertension (WCH), underwent ABPM. Average clinic BP in the ISH group was 184/83 mm Hg, in the SDH group 172/101 mm Hg, and in the WCH group 166/91 mm Hg, where as the ABPM averages were 169/80, 167/95 and 132/73 mm Hg, respectively, and differences held true for both daytime and night-time. Five ISH and four SDH patients had S patterns on ABPM, while the other four ISH and six SDH patients exhibited I patterns; none of the nine WCH subjects had either S or I patterns. ECG revealed left ventricular hypertropy (LVH) and/or ischaemic changes in eight patients with S patterns (ISH and SDH groups combined), as opposed to two patients with I patterns and only one patient of the WCH group. This seems to further suggest that an S pattern of SBP elevation on ABPM may have worse prognostic implications than either an I pattern or no SBP elevation.     

A series of self-measurements by the patient is a reliable alternative to ambulatory blood pressure measurement

BACKGROUND: Several studies have reported overdiagnosis and overtreatment of hypertensive patients, especially in borderline hypertensives. AIM: To find a blood pressure measurement procedure that reduces the risk of misclassification to an acceptable level. METHOD: Comparative, prospective study over seven months of primary care patients with elevated initial blood pressures. Blood pressure measurements made by general practitioners (GPs), practice nurses, and patients were compared with ambulatory blood pressure measurements. RESULTS: Ninety-nine patients completed the study. Mean differences (systolic blood pressure) between different measurement procedures and ambulatory measurement ranged from +10 mmHg (doctor) to -1 mmHg (patient), and (diastolic) from +4 mmHg (doctor) to -2 mmHg (patient). Standard deviations of mean differences ranged from 12 mmHg (doctor/systolic) to 10 mmHg (patient/systolic), and from 8 mmHg (doctor/diastolic) to 7 mmHg (patient/diastolic). CONCLUSION: Self-measurements by the patient appear to be a reliable alternative to ambulatory blood pressure measurement. In diagnosing and managing mild hypertension, we recommend the use of a valid self-measuring device.     

Self-measurement and automatic measurement in ambulatory blood pressure monitoring

INTRODUCTION: There are strictly determined conditions under which blood pressure measurement should be done and diagnosis of hypertension made. The first BP measurement should be performed on both arms. If there is a difference, controls should be made on the side on which the pressure is higher. In older persons the Osler manoeuvre should be made in order to exclude pseudohypertension. One should be aware that in hospitalized patients the BP is lower due to the bed rest itself. SELF-MEASUREMENT OF BLOOD PRESSURE: It seems that erroneous interpretation of blood pressure fluctuation and the tendency for self-medication by patients are the most important shortcomings of blood pressure self-monitoring. According to the World Hypertension League instructions, the BP self-measurement is not recommended for patients obsessed by the disease, neurotic and anxious persons, old subjects and in those who are physically handicapped. Since the diagnosis of hypertension should be made by the physician in office conditions, in our opinion the evolution of the disease and effects of treatment should be estimated under the same conditions. BLOOD PRESSURE AMBULATORY MONITORING: Ambulatory 24-hour monitoring is of a considerable diagnostic, therapeutic and prognostic importance over the casual or self-measurement, but one should be familiar with some peculiarrities of this method. Due to the adaptation to the device, the values of BP on the first measurement, particularly during the first 5 hours are significantly higher than during the subsequent measurements. In some subjects the values during the night may be higher due to the sleeping disturbances caused by the procedure. Differentiation between dippers and non-dippers has some prognostic and therapeutic implications. White coat hypertension may be successfully established by the ambulatory measurement. There is also a correlation between the BP variations and the myocardial mass. The trough:peak ratio may contribute to the estimation of efficiency of a certain drug. There are particular indications for ambulatory BP monitoring: the differences between the office and home values of BP are considerable; borderline hypertension; hypertension without signs of the target-organ damage; transitory hypertension of hypotension; syncopal attacks; vague symptoms in hypertensive patients; atypical or nocturnal angina; evaluation of the efficiency and duration of drug action; for research purposes.     

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.