Does placebo lower blood-pressure?

Effect of weight loss on blood pressure changes in overweight patients: A systematic review and meta-analysis

To determine quantitative differences between weight loss and changes in clinic blood pressure (BP) and ambulatory BP in patients with obesity or overweight, the authors performed a meta-analysis. PubMed, Embase, and Scopus databases were searched up to June 2022. Studies that compared clinic or ambulatory BP with weight loss were included. A random effect model was applied to pool the differences between clinic BP and ambulatory BP. Thirty-five studies, for a total of 3219 patients were included in this meta-analysis. The clinic systolic blood pressure (SBP) and diastolic blood pressure (DBP) were significantly reduced by 5.79 mmHg (95% CI, 3.54-8.05) and 3.36 mmHg (95% CI, 1.93-4.75) after a mean body mass index (BMI) reduction of 2.27 kg/m² , and the SBP and DBP were significantly reduced by 6.65 mmHg (95% CI, 5.16-8.14) and 3.63 mmHg (95% CI, 2.03-5.24) after a mean BMI reduction of 4.12 kg/m² . The BP reductions were much larger in patients with a BMI decrease ≥3 kg/m² than in patients with less BMI decrease, both for clinic SBP [8.54 mmHg (95% CI, 4.62-12.47)] versus [3.83 mmHg (95% CI, 1.22-6.45)] and clinic DBP [3.45 mmHg (95% CI, 1.59-5.30)] versus [3.15 mmHg (95% CI, 1.21-5.10)]. The significant reduction of the clinic and ambulatory BP followed the weight loss, and this phenomenon could be more notable after medical intervention and a larger weight loss.

Time course for blood pressure lowering of beta-blockers with partial agonist activity

BACKGROUND

Beta-blockers are commonly used in the treatment of hypertension. We do not know whether the blood pressure (BP) lowering efficacy of beta-blockers varies across the day. This review focuses on the subclass of beta-blockers with partial agonist activity (BBPAA).

OBJECTIVES

To assess the degree of variation in hourly BP lowering efficacy of BBPAA over a 24-hour period in adults with essential hypertension.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for relevant studies up to June 2020: the Cochrane Hypertension Specialised Register; CENTRAL; 2020, Issue 5; MEDLINE Ovid; Embase Ovid; the World Health Organization International Clinical Trials Registry Platform; and ClinicalTrials.gov. We also contacted authors of relevant papers regarding further published and unpublished work. The searches had no language restrictions.

SELECTION CRITERIA

We sought to include all randomised and non-randomised trials that assessed the hourly effect of BBPAA by ambulatory monitoring, with a minimum follow-up of three weeks.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the included trials and extracted the data. We assessed the certainty of the evidence using the GRADE approach. Outcomes included in the review were end-point hourly systolic and diastolic blood pressure (SBP and DBP) and heart rate (HR), measured using a 24-hour ambulatory BP monitoring (ABPM) device.

MAIN RESULTS

Fourteen non-randomised baseline controlled trials of BBPAA met our inclusion criteria, but only seven studies, involving 121 participants, reported hourly ambulatory BP data that could be included in the meta-analysis. Beta-blockers studied included acebutalol, pindolol and bopindolol. We judged most studies at high or unclear risk of bias for selection bias, attrition bias, and reporting bias. We judged the overall certainty of the evidence to be very low for all outcomes. We analysed and presented data by each hour post-dose. Very low-certainty evidence showed that hourly mean reduction in BP and HR visually showed an attenuation over time. Over the 24-hour period, the magnitude of SBP lowering at each hour ranged from -3.68 mmHg to -17.74 mmHg (7 studies, 121 participants), DBP lowering at each hour ranged from -2.27 mmHg to -9.34 mmHg (7 studies, 121 participants), and HR lowering at each hour ranged from -0.29 beats/min to -10.29 beats/min (4 studies, 71 participants). When comparing between three 8-hourly time intervals that correspond to day, evening, and night time hours, BBPAA was less effective at lowering BP and HR at night, than during the day and evening. However, because we judged that these outcomes were supported by very low-certainty evidence, further research is likely to have an important impact on the estimate of effect and may change the conclusion.

AUTHORS' CONCLUSIONS

There is insufficient evidence to draw general conclusions about the degree of variation in hourly BP-lowering efficacy of BBPAA over a 24-hour period, in adults with essential hypertension. Very low-certainty evidence showed that BBPAA acebutalol, pindolol, and bopindolol lowered BP more during the day and evening than at night. However, the number of studies and participants included in this review was very small, further limiting the certainty of the evidence. We need further and larger trials, with accurate recording of time of drug intake, and with reporting of standard deviation of BP and HR at each hour.

Does the rising placebo response impact antihypertensive clinical trial outcomes? An analysis of data from the Food and Drug Administration 1990-2016

Background

Recent studies show that placebo response has grown significantly over time in clinical trials for antidepressants, ADHD medications, antiepileptics, and antidiabetics. Contrary to expectations, trial outcome measures and success rates have not been impacted. This study aimed to see if this trend of increasing placebo response and stable efficacy outcome measures is unique to the conditions previously studied or if it occurs in trials for conditions with physiologically-measured symptoms, such as hypertension.

Method

For this reason, we evaluated the efficacy data reported in the US Food and Drug Administration Medical and Statistical reviews for 23 antihypertensive programs (32,022 patients, 63 trials, 142 treatment arms). Placebo and medication response, effect sizes, and drug-placebo differences were calculated for each treatment arm and examined over time using meta-regression. We also explored the relationship of sample size, trial duration, baseline blood pressure, and number of treatment arms to placebo/drug response and efficacy outcome measures.

Results

Like trials of other conditions, placebo response has risen significantly over time (R² = 0.093, p = 0.018) and effect size (R² = 0.013, p = 0.187) drug-placebo difference (R² = 0.013, p = 0.182) and success rate (134/142, 94.4%) have remained unaffected, likely due to a significant compensatory increase in antihypertensive response (R² = 0.086, p<0.001). Treatment arms are likely overpowered with sample sizes increasing over time (R² = 0.387, p<0.0001) and stable, large effect sizes (0.78 ±0.37). The exploratory analysis of sample size, trial duration, baseline blood pressure, and number of treatment arms yielded mixed results unlikely to explain the pattern of placebo response and efficacy outcomes over time. The magnitude of placebo response had no relationship to effect size (p = 0.877), antihypertensive-placebo differences (p = 0.752), or p-values (p = 0.963) but was correlated with antihypertensive response (R² = 0.347, p<0.0001).

Conclusions

As hypothesized, this study shows that placebo response is increasing in clinical trials for hypertension without any evidence of this increase impacting trial outcomes. Attempting to control placebo response in clinical trials for hypertension may not be necessary for successful efficacy outcomes. In exploratory analysis, we noted that despite finding significant relationships, none of the trial or patient characteristics we examined offered a clear explanation of the rise in placebo and stability in outcome measures over time. Collectively, these data suggest that the phenomenon of increasing placebo response and stable efficacy outcomes may be a general trend, occurring across trials for various psychiatric and medical conditions with physiological and non-physiological endpoints.

Novel Approaches to Investigate One-Carbon Metabolism and Related B-Vitamins in Blood Pressure

Hypertension, a major risk factor for heart disease and stroke, is the world's leading cause of preventable, premature death. A common polymorphism (677C→T) in the gene encoding the folate metabolizing enzyme methylenetetrahydrofolate reductase (MTHFR) is associated with increased blood pressure, and there is accumulating evidence demonstrating that this phenotype can be modulated, specifically in individuals with the MTHFR 677TT genotype, by the B-vitamin riboflavin, an essential co-factor for MTHFR. The underlying mechanism that links this polymorphism, and the related gene-nutrient interaction, with hypertension is currently unknown. Previous research has shown that 5-methyltetrahydrofolate, the product of the reaction catalysed by MTHFR, appears to be a positive allosteric modulator of endothelial nitric oxide synthase (eNOS) and may thus increase the production of nitric oxide, a potent vasodilator. Blood pressure follows a circadian pattern, peaking shortly after wakening and falling during the night, a phenomenon known as 'dipping'. Any deviation from this pattern, which can only be identified using ambulatory blood pressure monitoring (ABPM), has been associated with increased cardiovascular disease (CVD) risk. This review will consider the evidence linking this polymorphism and novel gene-nutrient interaction with hypertension and the potential mechanisms that might be involved. The role of ABPM in B-vitamin research and in nutrition research generally will also be reviewed.

Effect of fermented milk product containing lactotripeptides and plant sterol esters on haemodynamics in subjects with the metabolic syndrome – a randomised, double-blind, placebo-controlled study

We investigated the effects of fermented milk product containing isoleucine–proline–proline, valine–proline–proline and plant sterol esters (Pse) on plasma lipids, blood pressure (BP) and its determinants systemic vascular resistance and cardiac output. In a randomised, double-blind, placebo-controlled study, 104 subjects with the metabolic syndrome (MetS) were allocated to three groups in order to receive fermented milk product containing (1) 5 mg/d lactotripeptides (LTP) and 2 g/d plant sterols; (2) 25 mg/d LTP and 2 g/d plant sterols; (3) placebo for 12 weeks. Plasma lipids and home BP were monitored. Haemodynamics were examined in a laboratory using radial pulse wave analysis and whole-body impedance cardiography in the supine position and during orthostatic challenge. There were no differences between the effects of the two treatments and placebo on the measurements of BP at home or on BP, systemic vascular resistance index and cardiac index in the laboratory, neither in the supine nor in the upright position. The changes in plasma LDL-cholesterol concentration were − 0·1 (95 % CI − 0·3, 0·1 and − 0·3, 0·0) mmol/l in the 5 and 25 mg/d LTP groups, respectively, and +0·1 (95 % CI − 0·1, 0·3) mmol/l during placebo (P= 0·024). Both at baseline and at week 12, the increase in systemic vascular resistance during head-up tilt was lower in the 25 mg/d LTP group than in the 5 mg/d LTP group (P< 0·01), showing persistent differences in cardiovascular regulation between these groups. In subjects with the MetS, intake of LTP and Pse in fermented milk product showed a lipid-lowering effect of borderline significance, while no antihypertensive effect was observed at home or in the laboratory.

Placebo effect and efficacy of nebivolol in patients with hypertension not controlled with lisinopril or losartan: a phase IV, randomized, placebo-controlled trial

BACKGROUND

Most patients with hypertension require more than one antihypertensive to achieve blood pressure (BP) control.

OBJECTIVE

The purpose of this trial was to assess the efficacy and tolerability of add-on nebivolol, a vasodilatory β-blocker, in patients with untreated or poorly controlled hypertension, receiving stable therapy with lisinopril (an angiotensin-converting enzyme inhibitor) or losartan (an angiotensin II receptor blocker).

STUDY DESIGN

This was a phase IV double-blind, placebo-controlled trial conducted from August 2008 to March 2010 (ClinicalTrials.gov identifier: NCT00734630). Patients entered a 2-week, single-blind, placebo-only washout phase, followed by a 3- to 4-week open-label lead-in phase (lisinopril, 10-20 mg/day, or losartan, 50-100 mg/day), and a 12-week randomized, double-blind add-on treatment phase with placebo or nebivolol (5-40 mg/day).

SETTING

This study was conducted at 76 outpatient centers in the United States.

PATIENTS

Participants were men and women aged 18-85 years with a diagnosis of primary hypertension and seated trough systolic BP (SBP) at screening in the range of 170-200 mmHg if untreated, 155-180 mmHg if taking 1 antihypertensive medication, or 140-170 mmHg if taking 2 antihypertensive medications.

INTERVENTION

The intervention was 12 weeks' treatment with nebivolol 5-40 mg/day added to a background therapy of lisinopril 10-20 mg/day or losartan 50-100 mg/day.

MAIN OUTCOME MEASURES

Primary and secondary efficacy parameters were changes from baseline in seated trough cuff SBP and diastolic BP (DBP) at Week 12, respectively. Tolerability was assessed by monitoring treatment-emergent adverse events (TEAEs).

RESULTS

A total of 491 patients were randomized to receive nebivolol (n=258) or placebo (n=233). Efficacy analyses were conducted for 256 nebivolol and 232 placebo patients (intent-to-treat population); completion rates were 88.8% and 85.8%, respectively. Mean baseline SBP/DBP values were 163.1/98.2 mmHg (nebivolol) and 162.4/96.8 mmHg (placebo). Nebivolol was associated with a non-significant mean±SD reduction in SBP (-10.1±16.9 mmHg) versus placebo (-7.3±15.9 mmHg, P=0.093) and significant mean DBP reduction (-7.8±10.1 mmHg vs -3.5±10.6 mmHg, P<0.001). Subgroup analysis suggested a significant effect on DBP for patients receiving background losartan treatment (-8.1±9.2 mmHg vs -3.1±9.4 mmHg, P<0.001), but not for those receiving lisinopril (-7.6±10.8 mmHg vs -3.8±11.6 mmHg, P=0.076). A total of 28% nebivolol-treated and 22% placebo-treated patients reported a TEAE, the most frequent being upper respiratory tract infection (4.3% and 2.1%, respectively), bradycardia (2.7% and 0%), headache (2.3% and 2.1%), and nasopharyngitis (2.3% and 0.9%).

CONCLUSION

These data suggest that nebivolol, when added to lisinopril or losartan, results in an additional BP reduction; however, only the effect on DBP reached statistical significance. A subanalysis suggests that the effect on DBP may be stronger in losartan-treated than lisinopril-treated patients. A relatively strong placebo effect may limit data interpretation. Nebivolol was well tolerated, as there was no difference in TEAEs between nebivolol and placebo.

FUNDING

This trial (NCT00734630) was funded by Forest Laboratories, Inc.

The placebo effect and the autonomic nervous system: evidence for an intimate relationship

For many subjectively experienced outcomes, such as pain and depression, rather large placebo effects have been reported. However, there is increasing evidence that placebo interventions also affect end-organ functions regulated by the autonomic nervous system (ANS). After discussing three psychological models for autonomic placebo effects, this article provides an anatomical framework of the autonomic system and then critically reviews the relevant placebo studies in the field, thereby focusing on gastrointestinal, cardiovascular and pulmonary functions. The findings indicate that several autonomic organ functions can indeed be altered by verbal suggestions delivered during placebo and nocebo interventions. In addition, three experimental studies provide evidence for organ-specific effects, in agreement with the current knowledge on the central control of the ANS. It is suggested that the placebo effects on autonomic organ functions are best explained by the model of 'implicit affordance', which assumes that placebo effects are dependent on 'lived experience' rather than on the conscious representation of expected outcomes. Nevertheless, more studies will be needed to further elucidate psychological and neurobiological pathways involved in autonomic placebo effects.

Antihypertensive effects of aspirin: what is the evidence?

Nonsteroidal anti-inflammatory drugs are known to increase blood pressure and blunt the effect of antihypertensive drugs. Surprisingly, it has been suggested recently that aspirin lowers blood pressure and could be used for preventing hypertension. This review summarizes published data on the effects of aspirin on blood pressure. Trials suggesting that aspirin administered at bedtime lowers blood pressure are uncontrolled, unmasked, and potentially biased. They also conflict with cohort studies showing an 18% increase in the risk of hypertension among aspirin users. Fortunately, short-term use of aspirin does not seem to interfere with antihypertensive drugs. Regardless of its effect on blood pressure, low-dose aspirin effectively prevents cardiovascular events in patients with and without hypertension, but its benefits should be carefully weighed against a potential increase in the risk of adverse effects such as gastric bleeding and hemorrhagic stroke, as well as a small increase in the risk of hypertension.

Hemodynamic effects at rest and during exercise of long-term sodium restriction in mild essential hypertension

During moderate sodium restriction for 9 months in 19 men (33 years) with previously untreated mild essential hypertension (EH) sodium excretion fell from 209 to 139 mmol/24 h. Concomitantly intraarterial pressure at rest sitting fell from 145/93 to 138/88 mmHg (5%) and during 100 W exercise from 168/90 to 162/86 mmHg (4%). The fall in BP was due to reduction in cardiac output (5-11% at rest and during exercise) while peripheral vascular resistance was raised (4-10%). Thus, moderate sodium restriction was not very efficient treatment in our patients with mild EH. The main hemodynamic disturbance of established EH--an increase in vascular resistance--was not normalized after 9 months of low salt diet.

Guiding antihypertensive treatment decisions using ambulatory blood pressure monitoring

Compared with isolated clinic measurements, ambulatory blood pressure monitoring (ABPM) provides an insight into blood pressure (BP) changes in everyday life and an estimate of the overall BP load exerted on the cardiovascular system over 24 hours. Cross-sectional evidence suggests a direct and significant relationship between ambulatory BP and organ damage. There is also longitudinal evidence for a superior predictive value of 24-hour BP in relation to the risk for cardiovascular morbidity and mortality as opposed to clinic BP. The usefulness of ABPM in pharmacologic studies aimed at evaluating the 24-hour antihypertensive efficacy of different drugs and drug combinations is now acknowledged. Among the mathematical indices available to explore 24-hour BP coverage by treatment, the ABPM-derived smoothness index provides a superior measure of the homogeneity of BP control compared with trough:peak ratios. The main applications of clinical practice should be in identifying patients with isolated office hypertension and those who are nonresponders to treatment, in assessing coverage of the 24-hour BP profile in high-risk patients and in diagnosing suspected treatment-related hypotension.

Effects of the Combination of Low-Dose Nifedipine GITS 20 mg and Losartan 50 mg in Patients with Mild to Moderate Hypertension

Most hypertensive patients require more than one medication to effectively control elevated blood pressure (BP) values. This multicenter, randomized, double-blind study was aimed at testing the efficacy and safety of the combination of low-dose nifedipine GITS 20 mg/ losartan 50 mg compared with either monotherapy in patients with grade 1 to 3 hypertension over an eight-week period. Of 352 patients enrolled in the study, 300 were randomized. All the three treatments lowered elevated BP without clinically relevant changes in heart rate. All the three treatments lowered mean 24-hour diastolic BP: nifedipine GITS/losartan -10.6 mm Hg, losartan -5.4 mm Hg, nifedipine GITS 20 mg -8.0 mm Hg. There was a statistically significant difference of diastolic BP change between patients receiving losartan compared with those receiving combination treatment (P < 0.05). Diastolic BP trough-to-peak ratio and smoothness index were highest in the patient group receiving combination therapy (70%). Nifedipine GITS monotherapy had the highest systolic BP trough-to-peak ratio of all treatment arms (78%) and higher diastolic BP trough-to-peak ratio and smoothness index than losartan monotherapy. All treatments were safe. These data provide evidence that in hypertensive patients combination of nifedipine GITS 20 mg and losartan 50 mg improves control of systolic and diastolic BP compared with either monotherapy.

Methodology to determine duration of action for antihypertensive drugs

OBJECTIVE

To review and comment on methods used to assess the duration of action of antihypertensive drugs.

DATA SOURCES

A MEDLINE search (1966-June 2000) using key terms such as trough-to-peak ratio and ambulatory blood pressure monitoring was conducted.

STUDY SELECTION

An article was considered for this review if it pertained to the assessment of the duration of action of antihypertensive drugs. Special attention was given to articles dealing with methodologic aspects.

DATA SYNTHESIS

Antihypertensive drugs with a long duration of action are thought to provide better therapeutic coverage against hypertensive complications compared with that of short-acting agents. Measuring blood pressure at the end of the dosing interval may be a way to assess the duration of action of a drug. However, the use of high doses of a short-acting agent to obtain sufficient effect when at trough concentrations can potentially cause dose-related adverse effects at the peak time, contributing to nonadherence to therapy and thus to adverse outcomes. To alleviate this problem, the US Food and Drug Administration (FDA) has conceptualized the trough-to-peak (T:P) ratio. Although this arithmetic index has since been widely used to characterize the duration and safety of blood pressure control achieved by antihypertensive agents, several methodologic flaws limit its interpretation in the clinic. Ambulatory blood pressure monitoring (ABPM) is a more reliable approach to assess the duration of action and outcome of antihypertensive therapy.

CONCLUSIONS

Different methodologic approaches exist to evaluate the duration of action of antihypertensive drugs. Although the T:P ratio has been suggested by the FDA, it is difficult to establish a fair comparison among various antihypertensive agents based solely on this index. Treatment evaluation based on ABPM may be preferable to those guided by T:P because ABPM is more reproducible and is now established as a predictor of cardiovascular risk.

Practice-based randomized controlled-comparison clinical trial of chiropractic adjustments and brief massage treatment at sites of subluxation in subjects with essential hypertension: pilot study

OBJECTIVE

To determine the feasibility of conducting a randomized clinical trial in the private practice setting examining short- and long-term effects of chiropractic adjustments for subjects with essential hypertension compared with a brief soft tissue massage, as well as a nontreatment control group.

DESIGN

Randomized controlled-comparison trial with 3 parallel groups.

SETTING

Private practice outpatient chiropractic clinic.

PATIENTS

Twenty-three subjects, aged 24 to 50 years with systolic or diastolic essential hypertension.

INTERVENTIONS

Two months of full-spine chiropractic care (ie, Gonstead) consisting primarily of specific-contact, short-lever-arm adjustments delivered at motion segments exhibiting signs of subluxation. The massage group had a brief effleurage procedure delivered at localized regions of the spine believed to be exhibiting signs of subluxation. The nontreatment control group rested alone for a period of approximately 5 minutes in an adjustment room.

MAIN OUTCOME MEASURES

Cost per enrolled subject, as well as systolic and diastolic blood pressure (BP) measured with a random-0 sphygmomanometer and patient reported health status (SF-36). Pilot study outcome measures also included an assessment of cooperation of subjects to randomization procedures and drop-out rates, recruitment effectiveness, analysis of temporal stability of BPs at the beginning of care, and the effects of inclusion/exclusion criteria on the subject pool.

RESULTS

Thirty subjects enrolled, yielding a cost of $161 per enrolled subject. One subject was later determined to be ineligible, and 6 others dropped out. In both the chiropractic and massage therapy groups, all subjects were classified as either overweight or obese; in the control group there were only 2 classified as such. SF-36 profiles for the groups were similar to that of a normal population. The mean change in diastolic BP was -4 (95% confidence interval [CI]: -8.6, 0.5) in the chiropractic care group, 0.5 (95% CI: -3.5, 4.5) in the brief massage treatment group, and -4.9 (95% CI: -9.7, -0.1) in the no treatment control group. At the end of the study period, this change was -6.3 (95% CI: 13.1, 0.4), -1.0 (95% CI: -7.5, 15.6), -7.2 (95% CI: -13.3, -1.1) in the 3 study groups. The mean improvements in the chiropractic care and no treatment control groups remained consistent over the follow-up period.

CONCLUSIONS

This pilot study elucidated several procedural issues that should be addressed before undertaking a full-scale clinical trial on the effects of chiropractic adjustments in patients with essential hypertension. A multidisciplinary approach to recruitment may need to be used in any future efforts because of the limited subject pool of patients who have hypertensive disease but are not taking medications for its control. Measures need to be used to assure comparable groups regarding prognostic variables such as weight. Studies such as these demonstrate the feasibility of conducting a full-scale 3-group randomized clinical trial in the private practice setting.

Blood pressure measurement in research

OBJECTIVE

The aim of this paper is to summarize the issues raised during a consensus conference on the role of different blood pressure (BP) monitoring techniques in research, including pathophysiological studies, clinical outcome trials and clinical pharmacology trials.

METHODS

This review includes the contribution of the participants in a task force at the Eighth Consensus Conference on Ambulatory BP Monitoring (October 28-31, 2001, Sendai, Japan) and the results of a discussion open to all conference participants. Individual contributions have been summarized together with the points raised during the subsequent discussion, and the main statements are also presented in a table format.

POINTS OF CONSENSUS

(1) BP monitoring in pathophysiological studies. The essential role played by continuous BP monitoring in this field had been acknowledged, and further development of non-invasive beat-by-beat monitoring techniques has been advocated. (2) BP monitoring in clinical trials. In clinical trials automated ambulatory BP monitoring (ABPM) and self BP measurements (SBPM) at home share similar advantages, with specific features that make these approaches not alternative solutions but rather approaches able to complement each other. A few examples of application of ABPM and SBPM in clinical trials include the Treatment of Hypertension according to Home or Office Blood Pressure (THOP) trial and the Trial of Preventing Hypertension (TROPHY). (3) Use of ABPM in clinical pharmacology studies. Use of ABPM is now an established routine, aimed at describing the 24-h effect of new antihypertensive drugs. An example of these applications that was discussed in the conference is the use of ABPM in the evaluation of a new long-acting calcium channel blocker (Barnidipine) (J-MUBA study). (4) Specific models for the analysis of BP fluctuations. The features characterizing the chronobiological approach to description of 24-h BP profiles and its limitations (mainly consisting of the high risk of data over-modelling) are discussed. Also the possible occurrence of a circaseptan (approximately with a 7-day period) rhythm in BP has been addressed, although repeated performance of 24-h ABPM over a week obviously faces a number of practical problems. (5) Progress in technology: BP monitoring and telemedicine. The possibility to implement an interactive telemonitoring system of home SBPM values and the perspectives for a clinical application of this technology in the Hypertension Objective treatment based on Measurement by Electrical Devices of Blood Pressure (HOMED-BP) trial is discussed.

Echocardiographic studies on elderly patients with white coat hypertension to evaluate cardiac organ damages

This case-control study was aimed at evaluating the distribution of some echocardiographic signs of cardiac organ damages in elderly patients with white coat hypertension (WCH), as compared with a normotensive group of elderly. Correlations between the signs of cardiac organ damages and the clinical and ambulatory blood pressure parameters (obtained by means of a 24-h monitoring) have also been evaluated. The first screening covered 258 elderly subjects of both sexes, aged from 65 to 82 years, with clinical diagnosis of hypertension (systolic and diastolic blood pressures being higher than 160 and 95 mmHg, respectively). Of this group, 116 subjects remained in the final pool, and their echocardiographic parameters were compared with 33 normotensive (N) subjects. Out of the 116 clinically hypertensive patients, 29 (25%) displayed WCH, according to the established criteria. Variance analyses on the ranks followed by Dunn's test revealed no statistically significant differences between the N and WCH groups, while the hypertensive group (H) proved to be significantly different from both the N and the WCH groups. In addition to the descriptive statistics, an analysis of correlations between the pressure variables and the echocardiographic parameters has also been performed by means of a forward-stepwise multiple linear regression method. The models generated by this regression analysis covered only the ambulatory diurnal systolic pressure, and the clinical diastolic pressure in most of the cases of the echocardiographic parameters, taken as independent variables. In all these cases, the standardizecl correlation coefficient of the diurnal systolic pressure was always higher than that of the clinical diastolic pressure, indicating that the echocardiographic parameters depend more strongly on the first than on the second pressure value.

The placebo effect

Placebos have been traditionally regarded as deceptive therapies and have not been understood in the broader context of social symbols and of interpersonal factors that surround the healing process itself. Although the power of inert substances to heal is well recognized, the placebo effect also influences the outcome of conventional therapies. The role of the placebo in modern medicine is poorly defined because of a lack of a common understanding of what the placebo effect is and because of the negative connotions associated with its use. The response rate to placebo varies by illness. The natural course of disease and patient or physician bias can be misinterpreted as a placebo response. In research, the placebo effect is therapeutic noise to be removed by placebo-controlled trials. Few studies are designed to measure the placebo response rate directly. Placebos are a reminder of how little is known about mind-body interaction. The placebo effect may be one of the most versatile and underused therapeutic tools at the disposal of physicians.

Hemodilution reduces clinic and ambulatory blood pressure in polycythemic patients

Limited information is available for humans on whether blood viscosity affects total peripheral resistance and, hence, blood pressure. Our study was aimed at assessing the effects of acute changes in blood viscosity on both clinic and 24-hour ambulatory blood pressure (BP) values. In 22 normotensive and hypertensive patients with polycythemia, clinic and 24-hour ambulatory BPs were measured before and 7 to 10 days after isovolumic hemodilution; this was performed through the withdrawal of 400 to 700 mL of blood, with concomitant infusion of an equivalent volume of saline-albumin solution. Hematocrit, plasma renin activity, plasma endothelin-1, right atrial diameter (echocardiography), and blood viscosity were measured under both conditions. Plasma renin activity and right atrial diameter were used as indirect markers of blood volume changes. Plasma endothelin-1 was used to obtain information on a vasomotor substance possibly stimulated by our intervention, which could counteract vasomotor effects. Isovolumic hemodilution reduced hematocrit from 0.53+/-0.05 to 0.49+/-0.05 (P<.01). Plasma renin activity, plasma endothelin-1 and right atrial diameter were unchanged. Clinic blood pressure was reduced by hemodilution (systolic, 144.3+/-5.4 to 136.0+/-3.9 mm Hg[mean+/-SEM]; diastolic, 87.0+/-2.8 to 82.1+/-2.6 mm Hg, P<.05 for both) and a reduction was observed also for 24-hour average ABP (systolic, 133.6+/-2.9 to 129.5+/-2.7 mm Hg; diastolic, 80.0+/-2.0 to 77.3+/-1.7 mm Hg, P<.05 for both). The reduction was consistent in hypertensive patients (n = 12), whereas in normotensive patients (n = 10) it was small and not significant. Both clinic and 24-hour average heart rates were unaffected by the hemodilution. Thus, in polycythemia, reduction in blood viscosity without changing blood volume causes a significant fall in both clinic and 24-hour ambulatory BPs; this is particularly true when, as can often happen, blood pressure is elevated. This emphasizes the importance this variable may have in the determination of blood pressure and the potential therapeutic value of its correction when altered.

Assessment of antihypertensive treatment by ambulatory blood pressure

ADVANTAGES OF AMBULATORY BLOOD PRESSURE MONITORING: Ambulatory blood pressure monitoring is now used widely to assess the efficacy of antihypertensive drugs in daily life conditions. These 24-h measurements have a number of advantages compared to conventional sphygmomanometric readings. Although a small placebo effect is observed in the first few hours after placebo administration, 24-h average blood pressure is substantially devoid of any placebo effect. Moreover, ambulatory blood pressure is not affected by the alerting reaction usually observed during the doctor's visit. When the 24-h average value is considered, ambulatory blood pressure is more reproducible than clinic blood pressure. Finally, ambulatory blood pressure is prognostically more important than clinic blood pressure, since the end-organ damage associated with hypertension is more closely related to 24-h than to clinic blood pressure. Ambulatory blood pressure monitoring is therefore particularly useful when testing the efficacy of new antihypertensive agents on 24-h blood pressure. TESTING THE COMBINATION OF VERAPAMIL AND TRANDOLAPRIL: In a recent study we evaluated the efficacy of a fixed combination of verapamil and trandolapril using both clinic and ambulatory blood pressure measurements. Ambulatory blood pressure monitoring showed that the effect of the combination of verapamil and trandolapril was greater than the effect of either of the two drugs administered alone. However, the clinic blood pressure measurements failed to show any systemically greater effect with the combination versus monotherapy. This further indicates that ambulatory blood pressure is superior to conventional blood pressure in the assessment of antihypertensive drugs.

The placebo effect in cardiovascular disease

The effect of placebo on the clinical course of systemic hypertension, angina pectoris, silent myocardial ischemia, CHF, and ventricular tachyarrhythmias has been well described. In the prevention of myocardial infarction, there appears to be a direct relation between compliance with placebo treatment and favorable clinical outcomes. The safety of short-term placebo-controlled trials has now been well documented in studies of drug treatment of angina pectoris. Although the ethical basis of performing placebo-controlled trials continues to be challenged in the evaluation of drugs for treating cardiovascular disease, as long as a life-saving treatment is not being denied it remains prudent to perform placebo-controlled studies for obtaining scientific information.

Ambulatory blood pressure monitoring in clinical trials

Ambulatory blood pressure monitoring is increasingly used in clinical trials. The preliminary threshold values proposed for diagnosing hypertension and adjusting treatment based on ambulatory monitoring cannot yet be widely recommended because they have not been validated in prospective studies. The trough-to-peak or surface ratios may be useful instruments for assessing the duration of action of antihypertensive drugs. Trials with ambulatory monitoring just as clinical experiments based on conventional sphygmomanometry need to be properly controlled, because ambulatory blood pressure measurement is not completely devoid of a placebo effect. Ambulatory compared with conventional blood pressure measurements are characterized by higher reproducibility which makes it possible to reduce sample size in cross-over but not in parallel group trials. Finally, ambulatory monitors used in clinical research should have successfully passed one of the standardized validation protocols.

Ambulatory blood pressure, blood pressure variability and antihypertensive treatment

Ambulatory blood pressure monitoring is frequently employed in the clinical practice to improve the diagnosis of hypertension and the appropriateness of the decision regarding initiation of antihypertensive treatment. It is also frequently employed to check the efficacy of this treatment in conditions resembling daily life. This paper will describe the effect of a number of antihypertensive drugs on ambulatory blood pressure, based on data collected by our group in the past 10 years. It will then discuss the advantages of ambulatory blood pressure in studies of efficacy of antihypertensive drugs and the importance of this approach for definition of the trough-to-peak ratio of the antihypertensive effect. Some technical and clinical problems inherent to the ambulatory blood pressure monitoring approach will also be discussed.

Ambulatory monitoring uncorrected for placebo overestimates long-term antihypertensive action. Systolic Hypertension in Europe (SYST-EUR) Trial Investigators

This study compares blood pressure (BP) changes during active antihypertensive treatment and placebo as assessed by conventional and ambulatory BP measurement. Older patients (> or = 60 years, n=337) with isolated systolic hypertension by conventional sphygmomanometry at the clinic were randomized to placebo or active treatment consisting of nitrendipine (10 to 40 mg/d), with the possible addition of enalapril (5 to 20 mg/d) and/or hydrochlorothiazide (12.5 to 25 mg/d). At baseline, clinic systolic/diastolic BP averaged 175/86 mm Hg and 24-hour and daytime ambulatory BPs averaged 148/80 and 154/85 mm Hg, respectively. After 13 months (median) of active treatment, clinic BP had dropped by 22.7/7.0 mm Hg and 24-hour and daytime BPs by 10.5/4.5 and 9.7/4.3 mm Hg, respectively (P<.001 for all). However, clinic (9.8/1.6 mm Hg), 24-hour (2.1/1.1 mm Hg), and daytime (2.9/1.0 mm Hg) BPs decreased also during placebo (P<.05, except for daytime diastolic BP); these decreases represented 43%/23%, 20%/24%, and 30%/23% of the corresponding BP fall during active treatment. After subtraction of placebo effects, the net BP reductions during active treatment averaged only 12.9/5.4, 8.3/3.4, and 6.8/3.2 mm Hg for clinic, 24-hour, and daytime BPs, respectively. The effect of active treatment was also subject to diurnal variation (P<.05). Changes during placebo in hourly systolic and diastolic BP means amounted to (median) 21% (range, -1% to 42%) and 25% (-3% to 72%), respectively, of the corresponding changes during active treatment. In conclusion, expressed in millimeters of mercury, the effect of antihypertensive treatment on BP is larger with conventional than with ambulatory measurement. Regardless of whether BP is measured by conventional sphygmomanometry or ambulatory monitoring, a substantial proportion of the long-term BP changes observed during active treatment may be attributed to placebo effects. Thus, ambulatory monitoring uncorrected for placebo or control observations, like conventional sphygmomanometry, overestimates BP responses in clinical trials of long duration.

Combinations of potassium, calcium, and magnesium supplements in hypertension

Dietary intakes of potassium, calcium, and magnesium have each been reported to lower blood pressure, but the extent of blood pressure reduction in epidemiological studies and clinical trials has tended to be small and inconsistent. We hypothesized that combinations of these mineral supplements would lower blood pressure and that the reductions would be greater than that usually reported in studies of each cation alone. One hundred twenty-five patients 82 men and 43 women) with untreated mild or borderline hypertension were randomly assigned to daily treatment with one of the following four regimens: 60 mmol potassium and 25 mmol (1000 mg) calcium, 60 mmol potassium and 15 mmol (360 mg) magnesium, calcium and magnesium, or placebo. Standardized clinic blood pressure measurements were obtained on 3 days at baseline and after 3 and 6 months of treatment. At baseline, systolic and diastolic blood pressures (mean +/- SD) were 139 +/- 12 and 90 +/- 4 mm Hg, respectively, and dietary intakes of potassium, calcium, and magnesium were 77 +/- 32, 19 +/- 13, and 12 +/- 52 mmol/d, respectively. The mean differences (with 95% confidence intervals) of the changes in systolic and diastolic blood pressures between the treatment and placebo groups were not significant: -0.7 (-4.3 to +2.9) and -0.4 (-2.9 to +2.1) for potassium and calcium, -1.3 (-4.4 to +1.8) and 0.4 (-2.5 to +3.3) for potassium and magnesium, and +2.1 (-1.8 to +6.0) and +2.2 (-1.0 to +5.4) for calcium and magnesium. In conclusion, this trial provides little evidence of an important role of combinations of cation supplements in the treatment of mild or borderline hypertension.

Cardiovascular function and glucocorticoid replacement in patients with hypopituitarism

OBJECTIVE

Retrospective analysis suggests an increased mortality from cardiovascular disease in hypopituitary adults; GH deficiency has been postulated to account for this. However, glucocorticoid replacement doses of 30 mg/day of hydrocortisone (HC) may be excessive, and could therefore be implicated in the increased cardiovascular mortality in this group of patients. The aims of this study were to establish whether patients with hypopituitarism have any abnormalities of the cardiovascular system compared to a control group and whether any of these parameters might be improved by reducing the replacement dose of glucocorticoid.

PATIENTS AND MEASUREMENTS

A prospective analysis of cardiovascular function was carried out in 13 patients with hypopituitarism on routine replacement therapy and 20 normal controls who were matched for age and body mass index (BMI). Twenty-four-hour ambulatory blood pressure (BP), erect and supine BP, echocardiography, forearm plethysmography and cardiovascular reflexes in response to tilt, Valsalva and isometric hand grip were performed on controls and on patients taking 30 mg/day of HC and repeated following a reduction in HC dose to 15 mg/day for 3 months. Weight, plasma and urinary electrolytes, 24-hour urinary cortisol excretion, glucose, HbA1C and pituitary function were also assessed on HC 30 mg/day and 15 mg/day.

RESULTS

Mean 24-hour ambulatory BP, in addition to day and night time BP, was lower in patients than in controls (achieving statistical significance in the male subgroup) and did not change significantly with a reduction in HC dose. Erect and supine BP was also lower in patients compared to controls and there was no evidence of postural hypotension following a reduction in HC dose to 15 mg/day. Systolic and diastolic left ventricular dimensions, interventricular septal thickness, ejection fraction and fractional shortening were similar in controls and patients and did not alter with a reduction in HC dose. Systolic and diastolic BP and heart rate responded appropriately to all tests of cardiovascular reflexes (tilt, Valsalva and isometric handgrip) in hypopituitary patients though again measurements of systolic BP were significantly lower in patients during these tests, independent of HC dose. Forearm plethysmography was similar in patients receiving 30 mg of HC and controls but forearm blood flow increased significantly when the HC dose was reduced to 15 mg/day. There was no change in weight, plasma and urinary electrolytes, glucose and HbA1C or pituitary function in the patient group throughout the study.

CONCLUSIONS

In contrast to other studies we have failed to confirm cardiovascular dysfunction in GH deficient hypopituitary adults. Indeed, cardiovascular protection may be conferred on this group by the lower BP levels. Although a reduction in hydrocortisone dose was well tolerated in all patients, it appeared to confer no additional clinical benefit over the 3-month study period. In view of the conflicting data on cardiovascular function in hypopituitary patients, further prospective mortality studies are required in patients with adult GH deficiency.

Ambulatory blood pressure monitoring in the evaluation of antihypertensive treatment: additional information from a large data base

Aims of our study were i) to compare in a large number of hypertensive subjects the relative effect of antihypertensive treatment on clinic (C) blood pressure (BP) and various ambulatory (A) BP components, and ii) to determine whether antihypertensive treatment affects BP variability. In 266 mild essential hypertensive outpatients (age: 18-78 years) CBP (trough measurements) and ABP (Spacelabs 90202 or 90207) were measured after 3 to 4 weeks of wash-out and after 4 to 8 weeks of treatment with an ACE-inhibitor (n = 135) or a calcium-antagonist (n = 131). ABP recordings were analyzed to obtain average 24 h, day-time (6 a.m. to midnight) and night-time (midnight to 6 a.m.) systolic and diastolic BP values and standard deviations (BP variabilities). Treatment reduced both CBP and ABP. Treatment-induced changes in CBP showed a poor correlation with those in 24h, day- and night-time BP (r never > 0.23) and the correlation was poor also when trough ABP (mean of last 2 h) was considered. Twenty-four hour, day- and night-time BP were similarly reduced by treatment with a direct relationship between the initial BP values and the subsequent BP falls. BP standard deviations were also reduced by treatment in relation to the pretreatment values but the overall reduction was small, limited to the day-time and proportional or less than proportional to the reduction in mean values, with no changes or an increase in variation coefficients. The effects of ACE-inhibitor and calcium-antagonist treatments were superimposable. Our results from a large data base show that antihypertensive treatment effectively reduces all ABP components. The reduction cannot be predicted by the concomitant fall in CBP but it relates to the initial ABP values. Treatment has a limited effect on BP variability, this being the case both for ACE-inhibitors and calcium-antagonists.

Unchanged central hemodynamics after six months of moderate sodium restriction with or without potassium supplement in essential hypertension

Sodium (Na) restriction and potassium (K) supplementation has been recommended as treatment of essential hypertension but the mechanism by which these may reduce blood pressure (BP) is unknown. We examined if moderately reduced Na intake, combined with a low-Na/high-K salt alternative (Pansalt: NaCl 57%, KCl 28%, MgSO4 12%) as substitute for standard table salt, induced clinically significant BP reduction in hypertensive patients and, if this therapy reduced total peripheral resistance. After a 2-month control period 40 patients aged 21-67 years with mean casual BP 156/103 mmHg were given a salt restricted diet (120 mmol Na/24 h) for 6 months. In addition, they were randomised in a double-blind manner to receive either Pansalt (P-group) or standard NaCl (S-group) as table salt in small amounts. Cardiac output was measured by dye dilution. Daily Na excretion was similarly reduced (20%) in both groups while K excretion was slightly increased in the P-group and reduced in the S-group (difference p < 0.05). No large changes occurred in 24-h ambulatory BP (by Accutracker II) or intraarterial pressure (through a brachial artery catheter) at rest or during exercise while casual BP was reduced (p < 0.05) 13/8 mmHg in the P-group and 8/5 mmHg in the S-group. While cardiac output was slightly reduced at rest and during 50W exercise in the P-group, no significant changes were seen in total peripheral resistance in either group. Thus, moderate reduction in Na intake, with or without addition of K, is not sufficient to induce significant long-term intraarterial or 24-h ambulatory BP changes in essential hypertension. Without BP changes invasively determined central hemodynamics remains remarkably stable over a 6-month period.

"White coat" hypertension and alerting reaction in elderly and very elderly hypertensive patients

"White coat" hypertension can be demonstrated in 20-25% of younger patients with mild-to-moderate hypertension. In a population of 50 untreated hypertensive patients > or = 70 years (mean age 79 +/- 6 years, office blood pressure > or = 160 mmHg systolic and > or = 95 mmHg diastolic) ambulatory blood pressure monitoring, ECG and echocardiography were performed to assess the frequency of "white coat" hypertension and the alerting reaction ("white coat" effect). "White coat" hypertension was diagnosed, if mean daytime ambulatory blood pressure was < or = 146/87 mmHg (taken as upper "normal" limit), "definite" hypertension, if > 146/87 mmHg. Nine patients (18%) were classified as "white coat", 28(56%) as "definite" hypertensives, 13(26%) as an "intermediate" group. There were no differences in gender, weight, concomitant diseases, pre-study treatment, and systolic or diastolic left ventricular function between the groups. Patients with "white coat" hypertension showed lower office blood pressure (178 +/- 13/98 +/- 3 vs 201 +/- 19/104 +/- 7 mmHg; p < 0.004), lower left ventricular mass index (131 +/- 9 vs 139 +/- 26 g/m2, p < 0.5), no left ventricular hypertrophy (ECG-criteria; p < 0.05), a more pronounced alerting reaction (39 +/- 13/22 +/- 5 vs 27 +/- 17/8 +/- 9; p < 0.01) and no correlation between office blood pressure and left ventricular mass compared to the "definite" hypertension group. The total group showed an average alerting reaction of 30 +/- 19/12 +/- 8 mmHg. It is concluded that "white coat" hypertension and an alerting reaction can be demonstrated in untreated elderly and very elderly hypertensive patients. Patients with "white coat" hypertension are characterized by a milder degree of hypertension, less cardiac target organ damage and a more pronounced alerting reaction. The prognostic significance of "white coat" hypertension in the elderly needs to be reevaluated in a larger population.

Dose-effect relationship of rilmenidine after chronic administration

The antihypertensive efficacy and acceptability of 3 doses of rilmenidine (0.5, 1 and 2 mg, once daily) and a placebo over a 4 week period have been compared in a randomised, double-blind, parallel-group trial in 60 mild to moderate hypertensive patients. Six patients dropped out: 4 in the 2 mg-group and one in the 1 mg-group because of adverse events, and one in the placebo group for personal reason. The blood pressure was significantly decreased after the 1 and 2 mg doses with the maximum antihypertensive effect already being obtained after 1 mg. A significant dose-effect relationship was shown for supine systolic blood pressure (P = 0.05) but not for the supine diastolic blood pressure. The most beneficial efficacy/acceptability ratio was achieved at the dose of 1 mg once daily, which demonstrated the maximum antihypertensive effect associated with a low incidence of adverse events.

Long-term hemodynamic effects at rest and during exercise of newer antihypertensive agents and salt restriction in essential hypertension: review of epanolol, doxazosin, amlodipine, felodipine, diltiazem, lisinopril, dilevalol, carvedilol, and ketanserin

Hypertension is due to disturbance of the complex interplay between numerous known and unknown mechanisms that normally control blood pressure. Antihypertensive agents may, therefore, reduce blood pressure through widely different actions and, at the same time, elicit counterregulatory responses. This is a review of the long-term hemodynamic effects at rest as well as during exercise of nine relatively new antihypertensive compounds: a beta-blocker (epanolol), an alpha-receptor blocker (doxazosin), two double-acting compounds (dilevalol and carvedilol), three calcium antagonists (amlodipine, felodipine, and diltiazem), an angiotensin-converting enzyme inhibitor (lisinopril), a serotonin antagonist (ketanserin), and low-salt diet as a nonpharmacological treatment in 171 patients with mild to moderate essential hypertension. The results in the treatment groups are compared to the hemodynamic changes seen in 28 hypertensive patients left untreated for 10 years. The patient populations of the different groups were comparable. The invasive hemodynamic technique, including intraarterial blood pressure recording and measurements of cardiac output by Cardigreen, was the same in all studies. While blood pressure remained nearly unchanged in the untreated group, all antihypertensive compounds induced significant and sustained blood pressure reduction both at rest and during exercise. The modest reduction (3-5%) in blood pressure during a low-salt diet was also statistically significant. This review shows the multiplicity of the long-term hemodynamic changes, ranging from a reduction in cardiac output to peripheral vasodilatation, during chronic antihypertensive therapy. In untreated hypertensives, the cardiac output is reduced by 1-2% per year and total peripheral resistance is increased by 2-3% per year. The review also focuses on counterregulatory responses and modify the initial reduction in blood pressure after drug treatment for hypertension. It is concluded that proper understanding of the hemodynamic effects of antihypertensive agents is useful in the selection of the right treatment for specific groups of hypertensive patients.

Evaluation of the antihypertensive effect of once-a-day trandolapril by 24-hour ambulatory blood pressure monitoring. The Italian Trandolapril Study Group

The aim of this study was to evaluate the effects of trandolapril on 24-hour blood pressure in patients with mild-to-moderate essential hypertension. After a washout period of 4 weeks, 42 patients were randomized to receive 2 mg of trandolapril once daily and 20 to receive placebo in a double-blind fashion for 6 weeks. This was followed by a second washout period of 4 weeks. At the end of each period, clinic blood pressure was assessed at 24 hours after the last dose and 24-hour ambulatory blood pressure was measured noninvasively, taking blood pressure readings every 15 minutes during the day and every 20 minutes during the night. Two patients were dropped out before any blood pressure evaluation under treatment. Analysis of ambulatory blood pressure was performed in 48 patients who met the criteria for the minimal number of ambulatory blood pressure data (2 values per hour during the day and 1 value per hour in the night). In the trandolapril-treated group (n = 41) clinic systolic/diastolic blood pressures were 159.8 +/- 2.0/102.4 +/- 0.8, 146.8 +/- 2.3/94.8 +/- 1.1, and 155.7 +/- 2.0/99.2 +/- 0.7 mm Hg in the pretreatment, treatment, and post-treatment periods, respectively. The corresponding values for 24-hour mean blood pressure (n = 31) were 139.5 +/- 1.9/91.2 +/- 1.5, 131.0 +/- 2.0/84.3 +/- 1.2, and 139.7 +/- 1.8/90.9 +/- 1.1 mmHg. The differences between the lower treatment, versus the higher pre- and post-treatment, values were all statistically significant (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Thermal biofeedback treatment of mild hypertension. A comparison of effects on conventional and ambulatory blood pressure measures

Several studies have produced results suggesting that thermal biofeedback treatment is effective in lowering the blood pressure (BP) of individuals with both mild and moderate essential hypertension. This study used thermal biofeedback to treat 9 unmedicated individuals with mild hypertension. Subjects underwent 24-hour ambulatory BP monitoring both prior to and following the thermal biofeedback treatment regimen. Four of the subjects were considered treatment successes using standard office blood pressure assessments as the success-fail criteria. However, 24-hour ambulatory BP measures showed a markedly different pattern of results, with several subjects who were considered successes under conventional assessment techniques showing an increase in 24-hour ambulatory BP from pre- to posttreatment. There was a significant decrease in diastolic blood pressure for all subjects as measured by the ambulatory method. There was also a significant decrease in systolic and diastolic standing home blood pressure. The implications of these results are discussed.

Utilizing ambulatory blood pressure recordings to evaluate antihypertensive drug therapy

Until recently, the efficacy and pharmacodynamics of antihypertensive agents were assessed by resting blood pressure measurements in the doctor's office or a research clinic. The limitations of the office or clinic blood pressure measurement include the lack of representation (from recording only 1 point of time in the dosing schedule), the effects of the doctor's office on the patient's blood pressure, and, perhaps more relevant, observer bias. Ambulatory monitoring of the blood pressure has gained worldwide acceptance as an alternative method to assess antihypertensive drug efficacy and the time-effect relation of a drug. The ambulatory monitoring devices have been refined and are smaller, more precise, and more reliable than earlier recording models. Although there are no reference standards for analysis of ambulatory blood pressure data, international consensus groups are presently addressing this problem. Key roles for ambulatory blood pressure recordings in clinical trials of antihypertensive agents now include determination of the entry criteria for patients, improving the assessment of peak/trough pharmacodynamics in the patient's own environment (including nocturnal/sleep readings), and evaluating efficacy through calculation of the hypertensive burden, or blood pressure load.

Superiority of nonpharmacologic therapy compared to propranolol and placebo in men with mild hypertension: a randomized, prospective trial

We compared the effects of nonpharmacologic therapy, propranolol monotherapy, and placebo on blood pressure, metabolic, exercise, and quality of life variables in a 12-week, randomized, placebo-controlled trial of 79 male patients with hypertension. A significant reduction in diastolic blood pressure was observed with both nondrug therapy (-8.0 +/- 1.08 mm Hg) and propranolol (-9.5 +/- 1.46 mm Hg) compared to placebo (-0.1 +/- 2.01 mm Hg). However, only patients receiving nonpharmacologic therapy showed a reduced body mass index, lower total and low-density lipoprotein serum cholesterol levels, and increased exercise tolerance compared to both propranolol and placebo. Patients receiving propranolol felt less anxious and unsure but showed a significant decrement in nocturnal penile tumescence compared to both placebo and nondrug therapy. Patients receiving nondrug therapy felt more energetic and reported improved sexual arousal and greater sexual satisfaction after treatment. Reductions in blood pressure in the nondrug treatment group were related to both weight reduction and improved fitness. We conclude that nondrug therapy is effective in controlling blood pressure in men with mild hypertension and is associated with improvements in weight, lipoprotein levels, and exercise tolerance compared to both propranolol and placebo. Quality of life assessments further support the use of nondrug therapy in this context.

Dose-response relationships with antihypertensive drugs

A variety of antihypertensive drugs have been introduced into clinical practice at excessively high dose. Examples include most thiazide diuretics, propranolol, oxprenolol, atenolol, methyldopa, hydralazine and captopril. These very high doses have usually resulted from studies in which doses have been increased at regular intervals until the desired antihypertensive effect has been achieved or until unacceptable adverse effects have resulted. Frequently the starting doses were too high and the intervals between dose adjustment too short. In many cases these large doses resulted in unnecessary adverse effects--the adverse biochemical effects of thiazide diuretics, nephrotic syndrome, taste disturbances and neutropenia with captopril, the lupus syndrome with hydralazine and the central nervous system effects of methyldopa. Parallel group design with single doses and sufficient statistical power to distinguish between the upper and lower ends of the antihypertensive dose-response relationship should replace the dose-escalating design.

Effects of endurance training on baroreflex sensitivity and blood pressure in borderline hypertension

Physical training offers a potential nonpharmacological strategy for control of mild and borderline hypertension, but its effect on blood pressure is controversial. We investigated the effects of endurance training on waking and sleeping blood pressure and on baroreflex sensitivity in 16 borderline hypertensive patients. First, 8 patients were assessed before and after a 6-month endurance training programme. Then, when it was clear that blood pressures were lower after training, a further 8 patients were studied not only at the end of the training programme but also after 4 months' abstention from exercise (detraining). Measurements were taken of baroreflex sensitivity (response to iv phenylephrine), blood pressure, R-R interval, and blood pressure and R-R variability. Ambulatory blood pressures were measured in 13 patients (7 trained, 6 detrained) and sleep blood pressures in 6 patients (3 trained, 3 detrained). Increased fitness was associated with a decline in resting arterial blood pressure of 9.7 (SE 2.0) mm Hg systolic and 6.8 (1.2) mm Hg diastolic, and with a decline in ambulatory blood pressure of 4.8 (1.4) mm Hg and 7.5 (2.1) mm Hg, respectively; both p less than 0.05. Baroreflex sensitivity was 14.0 (1.8) ms/mm Hg in the unfit and 17.5 (2.0) ms/mm Hg in the fit; p less than 0.05. Sleep blood pressures were not lower in the fit despite longer sleep R-R intervals. These findings indicate that, in some subjects with borderline or mild hypertension, a physical training programme is sufficient to bring the blood pressure within normal limits.

Double-blind, randomized comparative study of the antihypertensive effect of nicardipine slow-release and nifedipine slow-release in hypertensive patients with coronary heart disease

The main aim of this study was to investigate whether a new slow-release formation of nicardipine can control hypertension and whether its antihypertensive effect is manifest throughout the dose intervals. In a randomized, double-blind placebo-controlled study, the antihypertensive effect of two calcium antagonists (Type II) was investigated in two independent groups of hypertensive patients with coronary artery disease. One group of patients received 40 mg nicardipine slow-release b.i.d. and the other 20 mg nifedipine slow-release b.i.d. The effect of the active drugs on blood pressure (BP), heart rate, and hemodynamics was compared with placebo within each group. In addition, a group comparison was made to establish whether nicardipine had any advantage over nifedipine. Twenty-eight patients [27 female, 1 male; 55 (41-72) years old], 18 with previous myocardial infarction (MI) entered the study (nicardipine, 15 patients; nifedipine, 13 patients). A placebo period of 3 days was followed by a 13-day drug treatment period. From the first to last trial day, BP and heart rate were measured three times daily. At the end of the placebo and the active drug periods, the following measurements were carried out: ambulatory BP monitoring by half-hourly recording for 12.5 hours with the Remler system, ergometric tests with ECG, and right heart catheterization. Both drugs lowered the BP at rest, during exercise, and during usual daily activities. The antihypertensive effect of nicardipine was significant for the daytime mean arterial BP (MAP) and for systolic BP and diastolic BP at various stages of the exercise tests. The difference between the effect of nicardipine and nifedipine was not significant.(ABSTRACT TRUNCATED AT 250 WORDS)