Genetic influence on blood pressure and lipid parameters in a sample of Polish twins

We studied 76 healthy monozygotic (MZ) and same-sex dizygotic (DZ) twin pairs (mean age 35 +/- 8 years, body mass index, BMI, 23.6 +/- 3.9 kg/m2) to determine genetic and environmental contributions to systolic (SBP) and diastolic (DBP) blood pressure, heart rate (HR) and serum lipids [total cholesterol (TC), low-density lipoprotein cholesterol (LDL-chol), high-density lipoprotein cholesterol (HDL-chol) and triglycerides (TG)I. SBP, DBP and HR were measured clinically and by ambulatory blood pressure monitoring (ABPM). Parameters of the genetic models for age-, sex- and BMI-adjusted data were estimated by model fitting and path analysis technique using LISREL 8. We found significant genetic effect on SBP and DBP for both clinical and ABP measurements, ranging from 37% for night-time ambulatory DBP to 79% for daytime ambulatory SBP. Estimates of genetic effects were higher for daytime than night-time ABP values, and higher for ambulatory 24-h SBP than office SBP measurements, with the reverse true for DBP. Significant genetic effect on HR ranged from 59% for office measurements to 69% for 24-h mean values. In summary, we also found genetic effect on TC, LDL-chol and HDL-chol with estimates ranging from 36% to 64%, but not on TG. Furthermore, a shared environmental component for TG was found, estimated at 36%. We showed significant genetic effect on both office and ambulatory BP and HR, with stronger genetic effect on daytime than night-time BP. We also found genetic effect on TC and lipoprotein fractions, but no significant genetic effect on TG. Environmental factors influencing serum TG, such as alcohol consumption, may explain the apparent lack of genetic effect in this healthy, non-obese population.     

Study of representative periods of day-time and night-time levels of blood pressure

The aim of this study is to assess whether it is possible to shorten ambulatory blood pressure (ABP) monitoring while getting measurements that precisely reflect 24 hours and daytime blood pressure (BP). METHODS: three hundred and thirty six young male subjects aged: 21 +/- 2 y, height: 178 +/- 7 cm, weight, 75 +/- 12 kg, with normal or "borderline" BP (casual BP: 138 +/- 13/79 +/- 8 mmHg) participated in the study. BP was recorded in each, every 15 minutes on 24 hours with a Spacelabs 5200 device. Systolic and diastolic BP on 24-h, during the 9 a.m. - 8 p.m. period (daytime) and BP related to the different subperiods included between 15 minutes and 6 hours were calculated. BP values obtained from the 196 subperiods were correlated with 24-h, daytime ABP and causal BP. Results were classified according to the value of correlation coefficient, slope and intercept of regressions. RESULTS: no subperiod accurately predict 24-h systolic BP (SBP) or diastolic BP (DBP) (the best correlation are established with the subperiods: 7 p.m.-01 a.m. for SBP; r = 0.916, p less than 10(-9), y = 0.76 x + 30; and 06 a.m.-12 a.m. for DBP; r = 0.914, p less than 10(-9), y = 0.87 x + 9). Four 6 hours subperiods sampled between 09 a.m.-3 p.m. and 12 a.m.-6 p.m. predict alike and in a reasonable way the daytime BP (SBP: r = 0.971, p less than 10(-9), y = 0.94 x + 8; r = 0.973, p less than 10(-9), y = 0.91 x + 7. Best correlations with casual BP are moderate (SBP: r = 0.674, DBP: r = 0.588). COMMENTS: BP measurements of subperiods smaller or equal to 6 hours cannot accurately predict the average 24-h BP. This is related mainly to the night-time/daytime BP fluctuations. Daytime BP can be estimated with short-term monitoring but the duration must not be smaller than 6 hours.     

White coat effect of alcohol

Numerous studies have shown a relationship between alcohol intake and elevated clinic blood pressures (BP). However, there have been few studies on the relationship between alcohol consumption and 24-h ambulatory BP monitoring. This study aimed to determine the relationship between alcohol intake, clinic BP, and 24-h ambulatory BP recordings to determine to what extent a white coat effect may contribute to the relationship between alcohol consumption and BP. Clinical BP and 24-h ambulatory BP were measured in 121 male volunteers aged 50.6 +/- 9.8 years (range, 30-70 years) who consumed between 0 and 2050 g of alcohol per week (mean, 394 +/- 342 g; median, 385 g/week). Supine clinical systolic BP (SBP) was significantly related to alcohol intake (beta = 0.242; P = .007). Alcohol consumption was not related to 24-h mean SBP or diastolic BP (DBP), daytime SBP or DBP, or nighttime SBP or DBP (daytime SBP: beta = 0.02, P = .802). Alcohol intake was significantly related to the difference between clinic SBP and mean daytime SBP (beta = 0.260, P = .004). Twenty-four-hour mean heart rate (HR), daytime mean and nighttime mean HR were strongly associated with alcohol intake (24-h HR: beta = 0.455, P < .001). These results suggest that the association between alcohol consumption and elevated BP is contributed to by a significant white coat effect and that excessive alcohol consumption may be a significant factor in explaining differences between clinic and ambulatory BP measurements.     

Ambulatory blood pressure monitoring in patients with hyperthyroidism before and after control of thyroid function

BACKGROUND AND OBJECTIVE: Thyroid hormones have pronounced effects on the cardiovascular system. Thyrotoxicosis affects blood pressure (BP), modifying both diastolic (DBP) and systolic (SBP) pressures. There are no studies examining BP with ambulatory blood pressure monitoring (ABPM) in hyperthyroidism before and after control of thyroid function. Our aims were (1) to analyse ABPM in a group of normotensive hyperthyroid patients before and after normalizing circulating thyroid hormones and (2) to compare these results with those obtained in a group of euthyroid subjects. PATIENTS AND MEASUREMENTS: We studied 20 normotensive hyperthyroid subjects [18 women; age (mean +/- SEM) 49.0 +/- 3.0 years] and 15 healthy subjects. Patients were evaluated by ABPM over 24 h, at diagnosis and after therapy (n = 18). RESULTS: The average 24-h, daytime and night-time SBP was significantly greater in hyperthyroid patients than in controls with no significant differences in DBP. Circadian BP rhythm, estimated by the difference between mean values of SBP, DBP and mean BP during daytime and night-time, was unchanged. The average 24-h and daytime SBP significantly decreased after normalizing thyroid function in the 18 hyperthyroid evaluated patients. Daytime SBP and DBP were higher than night-time values both before and after control of thyroid function. However, no differences in circadian BP rhythm were observed. CONCLUSIONS: Normotensive hyperthyroid patients exhibit higher ambulatory SBP throughout 24 h than normotensive euthyroid subjects. Control of hyperthyroidism decreases ambulatory SBP values. Mean nocturnal fall in BP is comparable in normotensive hyperthyroid patients and control subjects.     

Reproducibility of intra-arterial ambulatory blood pressure: effects of physical activity and posture

OBJECTIVE: To examine the effects of physical activity, body posture and sleep quality on the reproducibility of continuous ambulatory blood pressure monitoring. METHODS: Measurements were performed in 35 subjects (18 hypertensive, 11 male), mean +/- standard deviation age 49 +/- 13 years. Blood pressure (BP) was measured in the brachial artery, and beat-to-beat values of systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure and heart rate (HR) were computed. Physical activity and posture were continuously measured with five accelerometers. Subjective quality of sleep was assessed with a questionnaire. Reproducibility was expressed as an intraclass correlation coefficient and as the standard deviation of the within-subject differences. RESULTS: Posture and activity significantly influenced BP and HR. From lying to sitting, the SBP, DBP and HR increased 6 mmHg, 8 mmHg and 8 beats/min, respectively. From sitting to standing these respective increases were 4 mmHg, 2 mmHg and 13 beats/min. A further rise in activity (from standing to moving generally or walking) increased the SBP by 7 mmHg and the HR by 7 beats/min, and decreased the DBP by 8 mmHg. For daytime SBP, DBP and HR, the intraclass correlation coefficient (standard deviation of the within-subject differences) values were 0.93 (7.2 mmHg), 0.94 (3.8 mmHg) and 0.90 (4.1 beats/min). For night-time these respective values were 0.98 (4.4 mmHg), 0.97 (2.5 mmHg) and 0.96 (2.2 beats/min). Correction for physical activity level and posture hardly improved the reproducibility of daytime BP and HR. Reproducibility of night-time BP and HR was not improved by correction for physical activity, supine position or self-reported sleep quality. CONCLUSIONS: Within-subject differences between ambulatory BP recordings cannot be explained by differences in physical activity and body posture.     

Impact of blood pressure variability on cardiac and cerebrovascular complications in hypertension

BACKGROUND: The independent prognostic value of daytime and night-time blood pressure (BP) variability estimated by noninvasive 24-h BP monitoring is unclear. METHODS: We followed 2649 initially untreated subjects with essential hypertension for up to 16 years (mean, 6). Variability of BP was estimated by the standard deviation of daytime or night-time systolic BP (SBP) and diastolic BP (DBP). A BP variability either less than or equal to the group median or greater than the group median (12.7/10.4 mm Hg for daytime SBP/DBP and 10.8 and 8.9 mm Hg for night-time SBP/DBP) identified subjects at low or high BP variability. RESULTS: During follow-up there were 167 new cardiac and 122 new cerebrovascular events. The rate of cardiac events (x100 person-years) was higher (all P < .05) in the subjects with high than in those with low BP variability (daytime SBP: 1.45 v 0.72, daytime DBP: 1.29 v 0.91; night-time SBP: 1.58 v 0.62; night-time DBP: 1.32 v 0.85). The rate of cerebrovascular events was also higher (all P < .05) in the subjects with high than in those with low BP variability. In a multivariate analysis, after adjustment for several confounders, a high night-time SBP variability was associated with a 51% (P = .024) excess risk of cardiac events. The relation of daytime BP variability to cardiac events and that of daytime and night-time BP variability to cerebrovascular events lost significance in the multivariate analysis. CONCLUSIONS: An enhanced variability in SBP during the night-time is an independent predictor of cardiac events in initially untreated hypertensive subjects.     

Adrenal pheochromocytoma associated with dramatic cyclic hemodynamic fluctuations

A 52-year-old woman with a right adrenal pheochromocytoma had repetitive attacks of symptomatic hypotension/shock with systolic blood pressure (SBP)<50 mmHg followed by hypertension/hypertensive crises with SBP>300 mmHg. A non-invasive recording of beat-to-beat SBP, diastolic blood pressure (DBP), heart rate (HR), stroke volume (SV), cardiac output (CO) and total peripheral resistance (TPR) was collected for 346 min. Twenty hemodynamic cycles occurred during this time, lasting 17 min on average, with the most dramatic changes of TPR. The ratio of the highest to the lowest observed values was nearly 12:1 for TPR, over 6:1 for both SBP and DBP, over 4:1 for CO, and nearly 4:1 for SV and 2:1 for HR. The fluctuations of TPR preceded changes of all other hemodynamic variables.     

Rate of morning increase in blood pressure is elevated in hypertensives

BACKGROUND: We applied a new logistic curve fitting procedure to ambulatory blood pressure (ABP) recordings to determine whether the rate of increase in systolic (SBP), mean (MBP) and diastolic blood pressure (DBP) and heart rate (HR) in the morning is related to the level of BP in subjects. METHODS: The rate of transition in the morning and evening period was determined using a six-parameter double-logistic equation applied to 528 ABP recordings from a cardiovascular risk assessment clinic. Based on daytime BP (MBP, SBP, or DBP), the upper quartile (UQ, n = 132) and lower quartile (LQ) were compared. RESULTS: Subjects in the UQ of daytime MBP were hypertensive and showed greater day-night differences compared to normotensive subjects in the LQ (29 +/- 1 mm Hg for MBP compared to 20 +/- 1 mm Hg). The rate of morning increase in SBP and DBP was 42% and 30% greater in UQ subjects compared to the LQ subjects (P < .05). The rates of evening decrease in all BPs were 69% to 84% greater in the subjects in the UQ. Similar results were obtained if subjects were divided according to daytime SBP or DBP. The rate of morning increase in MBP was correlated with daytime BP, but not night-time or 24 h MBP. CONCLUSIONS: The rate of morning increase in BP is greater in those subjects with the highest daytime BP. The exaggerated rate of morning increase in BP in this group, which were all hypertensive, may also be important for greater cardiovascular risk.     

Rosiglitazone reduces office and diastolic ambulatory blood pressure following 1-year treatment in non-diabetic subjects with insulin resistance

OBJECTIVE: Rosiglitazone (RSG) has been reported to reduce blood pressure (BP) in patients with type-2 diabetes, but similar effects in non-diabetic people with insulin resistance is less clear. Our aim was to test the long-term BP-lowering effects of RSG compared with placebo. METHODS: We recruited participants for BP evaluation of RSG treatment from a larger intervention trial. Office BP was recorded in 355 non-diabetic subjects with insulin resistance randomized to receive either RSG or placebo for 52 weeks. Ambulatory BP monitoring (ABPM; Spacelab 90207) was performed in a subgroup of 24 subjects (RSG: n = 11; placebo n = 13). RESULTS: After 1 year, the office BP decreased by -3.1 mmHg systolic (p<0.05) and -3.8 mmHg diastolic (p<0.001) in the RSG group versus placebo. In patients treated with RSG, at 1 year there was a trend for a reduction from baseline for mean 24-h diastolic BP (DBP), daytime DBP and night-time DBP (-4.39, -5.26 and -2.93 mmHg, respectively). However, only daytime DBP was significantly lower in the RSG group compared with control (adjusted mean difference: -4.41 mmHg, p = 0.007). There was also a non-significant trend for a reduction in mean 24-h systolic BP (SBP), daytime SBP and night-time SBP (-2.70, -2.51 and -3.35 mmHg, respectively). CONCLUSIONS: RSG treatment for 1 year was associated with a small but significant decrease in diastolic 24-h ambulatory diastolic BP, and both systolic and diastolic office BPs in non-diabetic people with insulin resistance.     

Effect of Low-Dose Manidipine on Ambulatory Blood Pressure in Very Elderly Hypertensives

Summary. To evaluate the effect of manidipine 10 mg on 24-hour ambulatory blood pressure (BP) and heart rate (HR) in very elderly hypertensive patients, 54 patients aged 76–89 years (mean age 81.8 years) with systolic blood pressure (SBP) >160 mmHg and diastolic blood pressure (DBP) >90 mmHg were studied. After a 4-week placebo washout period, patients were randomized to receive manidipine 10 mg or placebo, both administered once daily for 8 weeks. Patients were checked after the initial run-in placebo phase and every 4 weeks thereafter. At each visit casual BP and HR were measured. At the end of the placebo period and after 8 weeks of active treatment, noninvasive 24-hour ambulate blood pressure measurement ABPM was performed. Manidipine significantly lowered casual sitting and standing SBP (P <0.001) and DBP (P <0.001) at the trough level. ABPM showed a significant decrease in 24-hour SBP and DBP values (P < 0,001), daytime SBP and DBP (P <0.001), and night-time SBP (P <0.001) and DBP (P <0.005). In addition, ABPM confirmed a consistent antihypertensive activity throughout the 24-hour dosing interval, without effect on the circadian BP profile. The trough/peak ratio was 0.67 for SBP and 0.59 DBP. No statistically significant change in HR was observed. The treatment was well tolerated, and there were no serious side effects. In conclusion, in very elderly hypertensive patients, once-daily administration of manidipine 10 mg was well tolerated and effective in reducing casual as well ambulatory BP.     

Ambulatory blood pressure monitoring in obese children: role of insulin resistance

OBJECTIVES: To investigate the relationship between ambulatory blood pressure (ABPM) parameters and insulin resistance in obese children. METHODS: A population of 56 obese prepubertal children was recruited for the study. They underwent ABPM, an oral glucose tolerance test and complete physical examination, including adiposity indexes such as body mass index (BMI), skinfolds, waist-to-hip ratio (WHR) and fat mass. RESULTS: The standard deviation score for BMI was significantly correlated with 24-h systolic blood pressure (SBP) (r = 0.30; P = 0.02) and diastolic blood pressure (DBP) (r = 0.29; P = 0.03), daytime SBP and DBP (r = 0.28; P = 0.04 and r = 0.32; P = 0.02), night-time SBP and DBP (r = 0.32; P = 0.01 and r = 0.27; P = 0.04). Fat mass was correlated with 24-h SBP (r = 0.46; P = 0.005), daytime SBP (r = 0.40; P = 0.01) and night-time SBP (r = 0.49; P = 0.03). No correlations were found between ABPM parameters and WHR. Furthermore, significant correlations were found between insulin resistance indexes, such as the homeostasis model assessment of insulin resistance and quantitative insulin-sensitivity check index, and 24-h DBP (r = 0.34; P = 0.01 and r = -0.29; P = 0.03), daytime DBP (r = 0.35; P = 0.009 and r = -0.34; P = 0.01) and daytime SBP (r = 0.32; P = 0.02 and r = -0.27; P = 0.04). Only 24-h and daytime DBP remained correlated with insulin resistance after adjustment for obesity. The analysis of the circadian rhythm of blood pressure revealed that 24 out the 56 children were non-dippers. CONCLUSIONS: The results of the present study indicate that adiposity and insulin resistance have an important role in influencing blood pressure in obese children, and also show a high prevalence of non-dipping phenomenon. This is of particular relevance because blood pressure tracks from childhood into adulthood and an already early-life high blood pressure is associated with an increased cardiovascular risk.     

THE EFFECTS OF POSTURAL CHANGES OF BAROREFLEX GAIN IN NORMAL AND HYPERTENSIVE PREGNANCIES

In order to understand the changes of baroreflex gain due to postural changes in normal pregnancies, we measured percentage changes (% changes) in blood pressure (SBP, DBP), heart rate (HR), stroke volume (SV), cardiac output (CO), total peripheral resistance (TPR) as well as cardiac autonomic nervous function (HF as an index of parasympathetic and LF/HF as an index of sympathetic function) and compared these parameters in normal pregnancies with those found in hypertensive pregnancies, such as chronic hypertensive (CHP) and severe preeclamptic pregnancies (PE), in late pregnancy (after 32 wks). When the position was changed from supine to standing in normal and non-pregnant women, the % changes of HR, DBP, TPR and LF/HF were increased and SBP, SV, CO and HF were decreased. The % changes of these parameters, however, were gradually decreased as pregnancy progressed, especially after 20–24 wks of gestation. In hypertensive pregnancies, however, even in late pregnancy, the decreased SBP and increased TPR was still observed and the profound decrease of CO and SV and increase of TPR were characteristic in PE when compared to CHP.     

Gender difference in the relation blood pressure-left ventricular mass and geometry in newly diagnosed arterial hypertension

Much evidence suggests sexual dimorphism in the relationship linking blood pressure (BP) to both left ventricular mass (LVM) and geometry in hypertension. To better evaluate gender-associated characteristics in the relation BP-LVM among newly diagnosed hypertension (24-h average ambulatory BP monitoring, ABPM, >?125/80 mmHg), we measured indexed LVM and relative wall thickness (RWT) by standardized echographic methods in 209 Caucasian drug-na?ve subjects, of whom 162 (100M/62F) were recognized to be hypertensive. Mean office systolic (SBP)/diastolic (DBP), 24-h average and night-time BP values were similar between sexes and significantly related to indexed LVM in both genders. Daytime SBP was significantly related to indexed LVM only in females (r =0.41; p =0.0008 in women; r =0.11; p = NS in males), while LVM was more sensitive to day-to-night SBP change in females. RWT was, on the contrary, significantly related to ABPM values only in males. All these findings were confirmed after adjusting for possible confounders. Percentage of LVM variance explained by 24-h average, daytime or night-time SBP values were higher in females than in males (17% vs 3%; 11% vs 1%; and 17% vs 8%). In conclusion, in early hypertension, LVM was significantly associated with daytime BP and more sensitive to reduced percentage of night BP fall in females. LVM variance explained by ABPM SBP was much higher in females than in males. RWT, expressing concentric LVM remodelling was, conversely, more related to BP increase in males.     

The effects of postural changes of baroreflex gain in normal and hypertensive pregnancies

In order to understand the changes of baroreflex gain due to postural changes in normal pregnancies, we measured percentage changes (% changes) in blood pressure (SBP, DBP), heart rate (HR), stroke volume (SV), cardiac output (CO), total peripheral resistance (TPR) as well as cardiac autonomic nervous function (HF as an index of parasympathetic and LF/HF as an index of sympathetic function) and compared these parameters in normal pregnancies with those found in hypertensive pregnancies, such as chronic hypertensive (CHP) and severe preeclamptic pregnancies (PE), in late pregnancy (after 32 wks). When the position was changed from supine to standing in normal and non-pregnant women, the % changes of HR, DBP, TPR and LF/HF were increased and SBP, SV, CO and HF were decreased. The % changes of these parameters, however, were gradually decreased as pregnancy progressed, especially after 20-24 wks of gestation. In hypertensive pregnancies, however, even in late pregnancy, the decreased SBP and increased TPR was still observed and the profound decrease of CO and SV and increase of TPR were characteristic in PE when compared to CHP.     

Antihypertensive efficacy of night-time graded-release diltiazem versus morning amlodipine in African Americans

BACKGROUND: The effect of a once daily night-time (10 pm) graded-release diltiazem (GRD) on early morning blood pressure (BP), heart rate (HR), and rate-pressure product (RPP) were compared with the effect of morning (8 am) amlodipine in 262 African American individuals with hypertension. METHODS: The multicenter, randomized, double-blind, parallel-group, dose-to-effect trial evaluated changes from baseline in BP, HR, and RPP (HR x systolic BP) by ambulatory BP monitoring during the first 4 h after awakening (diastolic BP = primary), between 6 am and 12 noon, and over a 24-h period. Patients were randomized to night-time GRD 360 mg (n = 132) or morning amlodipine 5 mg (n = 130) for 6 weeks, and were titrated to GRD 540 mg or amlodipine 10 mg after 6 weeks if clinic systolic BP/diastolic BP (SBP/DBP) was > or = 130/85 mm Hg. RESULTS: Compared with amlodipine, GRD showed significantly greater DBP reductions of 3.5 mm Hg (P < .0049) and 3.2 mm Hg (P < .0019) during the first 4 h after awakening and between 6 am and 12 noon respectively, as well as comparable reduction for the 24-h mean DBP. The SBP reductions during the morning periods were comparable, but the reduction in the 24-h mean SBP was 3.4 mm Hg greater (P < .0022) for amlodipine. Mean reductions in HR and RPP were significantly greater (P < or = .0008) for GRD during all intervals; amlodipine increased whereas diltiazem reduced HR with mean differences of 6.7 to 9.3 beats/min. Both treatments were well tolerated. CONCLUSIONS: Night-time GRD was more effective than morning amlodipine in reducing early morning DBP, HR, and RPP, as well as 24-h HR and RPP in African American individuals with hypertension. Amlodipine was more effective in reducing SBP over the 24-h period.     

Effect of doxazosin GITS on 24-hour blood pressure profile in patients with stage 1 to stage 2 primary hypertension

OBJECTIVE: To investigate the effect of the doxazosin gastrointestinal therapeutic system (GITS) on the 24 h blood pressure (BP) profile by ambulatory blood pressure measurements (ABPM) in patients with stage 1 to stage 2 primary hypertension. METHODS AND RESULTS: Seventeen hypertensive patients-either untreated or after a two-week run-in/washout period-underwent office and ABPM monitoring before and six weeks after an open-label once-daily morning dose of 4 mg of doxazosin GITS, an alpha(1)-adrenoceptor antagonist. Fourteen patients responded; three did not. Data analyses refers to the responders: linear analysis demonstrated statistically significant reductions from baseline in daytime, night-time, and total 24 h means for systolic BP (SBP) (7-10 mmHg) and diastolic BP (DBP) (5-10 mmHg) after treatment, with no statistically significant change in heart rate (HR). Rhythm analysis demonstrated statistically significant reductions from baseline in mean mesor (8 mmHg), maximum (6 mmHg) and minimum (10 mmHg) values in SBP, and in mean mesor (5 mmHg), maximum (7 mmHg) and minimum (5 mmHg) values in DBP. Circadian rhythm parameters in BP and HR were not significantly altered by treatment. Treatment with doxazosin GITS was well tolerated. CONCLUSIONS: A single morning dose of doxazosin GITS at 4 mg significantly reduced ambulatory SBP and DBP throughout a 24 h period while preserving a normal 24 h BP and HR rhythm profile in stage 1 to stage 2 hypertensives.     

Blood pressure response to antihypertension treatment. Comparison of data obtained at the doctor's office and by ambulatory blood pressure measurement

A comparative study of clinical and ambulatory responses to antihypertensive treatment was conducted retrospectively in 69 patients with mild to moderate arterial hypertension. The patients received different drugs, but blood pressure (BP) was measured by the same methods in each of them. (a) Clinical BP was measured with a mercury manometer some time after taking the last dose of antihypertensive drug: 24 hours in patients who took one daily dose, 12 hours in those who took two daily doses. (b) Ambulatory BP was measured with a Spacelabs SPM 5200 instrument over a minimum of 24 hours. The parameters compared were: (1) BP figures recorded. Correlation was very poor as regards both SBP (r = 0.42 before treatment, r = 0.55 after treatment) and DBP (r = 0.40 and r = 0.46 respectively). The mean BP value was lower in the ambulatory group than in the clinical group (-20/-12 mmHg), the difference being slightly less marked after treatment (-12/-6 mmHg). (2) Degree of absolute reduction of BP induced by treatment. Correlation was very poor between the two methods as regards both SBP (r = 0.46) and DBP (r = 0.49). (3) Proportion of responders and non-responders to treatment, the clinical response being defined as normalization and/or more than 10 p. 100 reduction of DBP, and the ambulatory response as a significant decrease of mean diastolic value over 24 hours. Among the 69 patients studied, there were 51 concordant cases (36 responders, 15 non-responders with the two methods) and 18 discordant cases (10 clinical responders but ambulatory non-responders, 8 clinical non-responders but ambulatory responders).(ABSTRACT TRUNCATED AT 250 WORDS)     

Prognostic significance of 24-h ambulatory blood pressure characteristics for cardiovascular morbidity in a population of elderly men

OBJECTIVE: This study aimed to investigate the prognostic significance of 24-h ambulatory systolic (SBP), diastolic (DBP) and pulse pressure (PP), and blood pressure (BP) variability for cardiovascular morbidity in elderly men. DESIGN AND METHODS: Twenty-four hour ABP monitoring was performed in 70-year-old men (n = 872) participating in a longitudinal population-based study. The population was followed for up to 9.5 years, and the relationship between different blood pressure components and cardiovascular (CV) morbidity was assessed by Cox proportional hazard analysis. RESULTS: During follow-up, 172 CV events occurred (2.97 per 100 person-years). SBP and PP, both office and ambulatory, were significant predictors of CV morbidity. Twenty-four hour ambulatory PP [hazard ratio (HR) for 1 SD increase in BP 1.32, 95% confidence interval (CI) 1.15-1.52] and daytime ambulatory PP (HR 1.29, 95% CI 1.13-1.48) predicted CV morbidity independently of office PP and other established CV risk factors. Addition of night-time PP to a regression model with daytime PP and covariates did not increase the predictive value. However, the variability of daytime SBP (adjusted HR 1.24, 95% CI 1.07-1.42) provided additional prognostic power, independently of the 24-h SBP level. CONCLUSIONS: Ambulatory PP was a powerful predictor of CV morbidity in elderly men, independently of office PP and other established cardiovascular risk factors. Moreover, variability of daytime SBP added important prognostic information, suggesting that 24-h ambulatory BP monitoring may contribute to an improved risk assessment in elderly subjects.     

Associated factors of home versus ambulatory heart rate variability in the general population: the Ohasama study

We previously demonstrated that heart rate (HR) variability obtained by daytime ambulatory monitoring and that of daily home measurement associated differently with cardiovascular mortality risk; cardiovascular mortality was linked with decreased daytime ambulatory HR variability and increased day-by-day home HR variability. The aim of this study was to identify factors contributing to each variability, clarifying possible reasons for their different predictive values. We obtained daytime ambulatory HR and home HR in 538 individuals of a general Japanese population aged ≥55 years. Daytime ambulatory HR variability and day-by-day home HR variability were estimated as a standard deviation measured every 30 min by daytime ambulatory monitoring and day-by-day home measurements once in the morning for 4 weeks, respectively. There was only weak correlation between daytime ambulatory HR variability and day-by-day home HR variability (r = 0.08～0.14). In a multiple regression model, daytime ambulatory HR variability was associated with daytime ambulatory HR (P < 0.0001), daytime ambulatory blood pressure (BP) variability (P < 0.0001), and male sex (P = 0.003), while negatively associated with daytime ambulatory systolic blood pressure (SBP) (P < 0.0001) and smoking (P = 0.038). Meanwhile, day-by-day home HR variability was positively associated with home HR (P < 0.0001), day-by-day home BP variability (P < 0.0001), and male sex (P = 0.018). Associated factors of daytime ambulatory HR variability and day-by-day home HR variability were different. Our findings suggest that HR variabilities by different intervals of measurements might be mediated by different mechanisms.     

The prospective, randomized investigation of the safety and efficacy of telmisartan versus ramipril using ambulatory blood pressure monitoring (PRISMA I)

OBJECTIVE: To compare the efficacy and safety of once-daily telmisartan and ramipril on blood pressure (BP) reductions during the last 6 h of the dosing interval. PATIENTS AND METHODS: In a prospective, randomized, open-label, blinded-endpoint study using ambulatory BP monitoring, 801 patients with mild-to-moderate hypertension were randomly assigned to once-daily treatment with telmisartan 80 mg for 14 weeks or ramipril 5 mg for 8 weeks and then force titrated to ramipril 10 mg for the last 6 weeks. Primary endpoints were the reduction from baseline in the last 6-h mean ambulatory systolic BP (SBP) and diastolic BP (DBP). Secondary endpoints included changes in 24-h, morning, daytime and night-time mean ambulatory BP and ambulatory BP response rates. RESULTS: Telmisartan 80 mg produced greater reductions in the last 6-h mean ambulatory SBP and DBP compared with ramipril 5 mg (P < 0.0001) and 10 mg (P < 0.0001), and was superior to ramipril for all secondary ambulatory SBP and DBP endpoints (P < 0.05). Ambulatory BP response rates (24-h mean ambulatory SBP/DBP < 130/80 mmHg or reduction from baseline > or = 10 mmHg) were greater with telmisartan 80 mg (P < 0.01) than with ramipril 5 and 10 mg. Ramipril was associated with a higher incidence of treatment-related cough (5.7 versus 0.5% for telmisartan). CONCLUSIONS: Telmisartan was significantly more effective than ramipril in reducing BP throughout the 24-h dosing interval and particularly during the last 6 h, a time when patients appear to be at greatest risk of cerebro- and cardiovascular events. Both drugs were well tolerated, although ramipril was associated with a higher incidence of cough.