Biomedical subjects

José E López

Publications and source records attributed to José E López.

At least 19 recordsLinked to original sources

PubMed2006

[Chronotherapy with torasemide in hypertensive patients: increased efficacy and therapeutic coverage with bedtime administration].

BACKGROUND AND OBJECTIVE: Torasemide is a high ceiling loop diuretic frequently used for treatment of heart failure, renal failure and hypertension, according to results mainly based on clinic blood pressure measurements, without proper evaluation of the 24-hour efficacy of the drug. Accordingly, we investigated the time-dependent antihypertensive efficacy of torasemide in hypertensive patients. PATIENTS AND METHOD: We studied 58 patients with grade 1-2 essential hypertension (25 men and 33 women), 48.7 (11.9) years of age, randomly assigned to receive torasemide (5 mg/day) either upon awakening or at bedtime. Blood pressure was measured by ambulatory monitoring for 48 consecutive hours before and after 6 weeks of therapy. RESULTS: Efficacy of torasemide was significantly higher with bedtime dosing (11.2 and 8.0 mmHg reduction in the 24-hour mean of systolic and diastolic blood pressure, respectively) as compared to the administration of the drug on awakening (6.2 and 3.7 mmHg reduction in systolic and diastolic blood pressure). The percentage of patients with controlled ambulatory blood pressure after treatment was also higher after bedtime treatment (54% versus 27%). The time-response curves indicate a full 24-hour therapeutic duration only when torasemide was administered before bedtime. With regard to the safety profile, 2 patients presented secondary effects (abdominal pain, diarrhea) in morning dose, and 4 patients taking the drug at bedtime reported nicturia. CONCLUSIONS: A dose of 5 mg/day torasemide is effective for blood pressure reduction after bedtime administration. The differences in efficacy and therapeutic duration as a function of the circadian time of treatment with torasemide here documented should be taken into account when prescribing this loop diuretic for treatment of patients with essential hypertension.

Blood Pressure↗

PubMed2006

[Effects of time-dependent administration of antihypertensive treatment in patients with resistant hypertension].

BACKGROUND AND OBJECTIVE: Patients with resistant hypertension represent an important clinical problem due to their poor control, high prevalence of target organ damage, and the associated increase in cardiovascular risk. Therapeutic strategies in resistant hypertension currently include a sequential change of drugs or the synergic combination of new drugs. Most patients, however, receive all their drugs in a single morning dose. We have evaluated the impact on the circadian pattern of blood pressure (BP) of modifying the time of treatment without increasing the number of prescribed drugs. PATIENTS AND METHOD: We studied 123 patients with resistant hypertension (73 men and 50 women), 59.9 (11.9) years of age, who were receiving 3 antihypertensive drugs in a single morning dose. Patients were randomly assigned to one of two groups according to the modification in their treatment strategy: a) Changing one of the drugs, but keeping all 3 in the morning. b) The same approach but prescribing one of the drugs to be taken at bedtime. Blood pressure was measured at 20-minute intervals from 07:00 to 23:00 hours and at 30-minute intervals at night for 48 consecutive hours at baseline and after 3 months of treatment with the new therapeutic scheme. RESULTS: There was a small and non-significant BP reduction when all drugs were still taken on awakening (p > 0.374). On baseline, only 22% of the patients in this group were dippers, and this percentage was further reduced to 15% after 3 months of therapy with all drugs on awakening. The blood pressure reduction was statistically significant (8.6 and 5.9 mmHg for systolic and diastolic blood pressure; p < 0.001) with one drug at bedtime. This effect was markedly larger in the nocturnal mean of blood pressure. Thus, while only 13% of the patients in this group were dippers at baseline, 53% were already dippers after 3 months of therapy. CONCLUSIONS: Results from this prospective trial indicate that, in patients with resistant hypertension, time of treatment may be more important for patient control and for the proper modeling of the circadian blood pressure pattern than just changing the drug combination.

Aged↗

PubMed2005

Aspirin administered at bedtime, but not on awakening, has an effect on ambulatory blood pressure in hypertensive patients.

OBJECTIVES: The purpose of this research was to investigate in untreated hypertensive patients the effects on ambulatory blood pressure (BP) of aspirin (ASA) administered at different times of the day. BACKGROUND: Previous studies have shown that ASA produces an administration time-dependent inhibition of angiotensin II. Low-dose ASA has also been shown to reduce BP when administered before bedtime, as opposed to upon awakening, in normotensive and hypertensive volunteers, and in pregnant women at high risk for preeclampsia. METHODS: We studied 328 untreated patients with grade 1 hypertension, 44.0 +/- 12.6 years of age, randomly divided into three groups: nonpharmacological hygienic-dietary recommendations, the same recommendations and ASA (100 mg/day) on awakening, or the same recommendations and ASA before bedtime. Blood pressure was measured every 20 min during the day and every 30 min at night for 48 consecutive h before and after 3 months of intervention. RESULTS: After three months of nonpharmacological intervention, there was a small and nonsignificant reduction of BP (<0.2 mm Hg; p = 0.648). Blood pressure was slightly elevated after aspirin on awakening (2.6/1.6 mm Hg in the 24-h mean of systolic/diastolic BP; p = 0.002). A significant BP reduction, however, was observed in the patients who received aspirin before bedtime (6.8/4.6 mm Hg in systolic/diastolic BP; p < 0.001). CONCLUSIONS: This prospective trial documents a significant administration time-dependent effect of low-dose ASA on BP in untreated hypertensive patients. The timed administration of low-dose ASA could provide a valuable approach, beyond the secondary prevention of cardiovascular disease, in the added BP control of patients with mild essential hypertension.

Adult↗

PubMed2005

Decrease in urinary albumin excretion associated with the normalization of nocturnal blood pressure in hypertensive subjects.

Previous results have indicated that valsartan administration at bedtime as opposed to on wakening improves the diurnal/nocturnal ratio of blood pressure without loss in efficacy and therapeutic coverage. We hypothesized that increasing this ratio could reduce microalbuminuria. We conducted a prospective, randomized, open-label, blinded endpoint trial on 200 previously untreated nonproteinuric patients with grade 1 to 2 essential hypertension, assigned to receive valsartan (160 mg/d) as a monotherapy either on awakening or at bedtime. Blood pressure was measured by ambulatory monitoring for 48 consecutive hours before and after 3 months of treatment. Physical activity was simultaneously monitored every minute by wrist actigraphy to accurately calculate the diurnal and nocturnal means of blood pressure on a per-subject basis. The significant blood pressure reduction after 3 months of therapy was similar for both treatment times. The diurnal/nocturnal blood pressure ratio was unchanged after valsartan on awakening, but significantly increased from 7.5 to 12.2 (P<0.001) when valsartan was administered at bedtime. Urinary albumin excretion was significantly reduced by 41% after bedtime treatment. This reduction was independent of the 24-hour blood pressure decrease but highly correlated with the decrease in nocturnal blood pressure and mainly with the increase in diurnal/nocturnal ratio (P<0.001). Bedtime valsartan administration improves the diurnal/nocturnal blood pressure ratio to a more dipper profile. This normalization of the circadian blood pressure pattern is associated with a significant decrease in urinary albumin excretion and plasma fibrinogen, and could thus reduce the increased cardiovascular risk in nondipper hypertensive patients.

Adult↗

PubMed2005

Differing administration time-dependent effects of aspirin on blood pressure in dipper and non-dipper hypertensives.

Aspirin is a potent antioxidative agent that reduces vascular production of superoxide, prevents angiotensin II-induced hypertension, and induces NO release. Low-dose aspirin administered at bedtime, but not on awakening, has also been shown to reduce blood pressure, possibly enhancing the nocturnal trough in NO production. Because endothelium-dependent vasodilation is blunted through a decrease in NO release in non-dipper compared with dipper patients, we compared the administration time-dependent influence of aspirin on ambulatory blood pressure in dipper and non-dipper hypertensive subjects. We studied 257 patients with mild hypertension (98 men and 159 women), 44.6+/-12.5 years of age, randomly assigned to receive 100 mg per day of aspirin either on awakening or at bedtime. Ambulatory blood pressure was measured for 48 hours at baseline and after 3 months of intervention. Blood pressure was slightly elevated after aspirin on awakening (increase of 1.5/1.0 mm Hg in the 24-hour mean of systolic/diastolic blood pressure; P<0.028). A highly significant blood pressure reduction was observed in patients who received aspirin at bedtime (decrease of 7.2/4.9 mm Hg in systolic/diastolic blood pressure; P<0.001). The reduction in nocturnal blood pressure mean was double in non-dippers (11.0/7.1 mm Hg) compared with dippers (5.5/3.3 mm Hg; P<0.001). This prospective trial corroborates the significant administration time-dependent effect of low-dose aspirin on blood pressure, mainly in non-dipper hypertensive patients. The timed administration of low-dose aspirin could thus provide a valuable approach, beyond prevention of cardiovascular disease, in the blood pressure control of patients with mild hypertension.

Adult↗

PubMed2005

Effects of time of day of treatment on ambulatory blood pressure pattern of patients with resistant hypertension.

Patients with resistant hypertension present high prevalence of a non-dipper blood pressure pattern. Recent results indicate that non-dipping is related partly to the absence of 24-hour therapeutic coverage in patients treated with single morning doses. Accordingly, we investigated the impact of treatment time on the blood pressure pattern in 700 patients with resistant hypertension on the basis of clinic measurements who were studied by 48-hour ambulatory monitoring. Among them, 299 patients received all their medication on awakening, and 401 were taking > or =1 antihypertensive drug at bedtime. The percentage of patients with controlled ambulatory blood pressure was double in patients taking 1 drug at bedtime (P=0.008). Among the 578 patients with true resistant hypertension, subjects receiving 1 drug at bedtime showed a significant reduction in the 24-hour mean of systolic and diastolic blood pressure (3.1 and 1.6 mm Hg, respectively; P<0.011). This reduction was much more prominent during nighttime (5.1 and 3.0 mm Hg; P<0.001). Accordingly, the diurnal/nocturnal blood pressure ratio was significantly increased by 2.7 and the prevalence on non-dipping reduced (56.9 versus 81.9%; P<0.001) in patients taking 1 drug at bedtime. Compared with patients receiving all drugs on awakening, subjects with 1 drug at bedtime also showed significant reductions in the average values of glucose, cholesterol, fibrinogen, and urinary albumin excretion (P<0.011). In patients with resistant hypertension, pharmacological therapy should take into account when to treat with respect to the rest-activity cycle of each patient to improve control and to avoid the non-dipper pattern associated to higher cardiovascular risk.

Activity Cycles↗

PubMed2005

Administration time-dependent effects of valsartan on ambulatory blood pressure in elderly hypertensive subjects.

Previous results have indicated that valsartan administration at bed-time, as opposed to upon wakening, improves the diurnal/nocturnal ratio of blood pressure (BP) toward a normal dipping pattern, without loss of 24 h efficacy. This ratio is characterized by a progressive decrease with aging. Accordingly, we investigated the administration time-dependent antihypertensive efficacy of valsartan, an angiotensin blocking agent, in elderly hypertensive patients. We studied 100 elderly patients with grade 1-2 essential hypertension (34 men and 66 women), 68.2+/-4.9 years of age, randomly assigned to receive valsartan (160 mg/d) as a monotherapy either upon awakening or at bed-time. BP was measured for 48 h by ambulatory monitoring, at 20 min intervals between 07:00 to 23:00 h and at 30 min intervals at night, before and after 3 months of therapy. Physical activity was simultaneously monitored every minute by wrist actigraphy to accurately determine the duration of sleep and wake spans to enable the accurate calculation of the diurnal and nocturnal means of BP for each subject. There was a highly significant BP reduction after 3 months of valsartan treatment (p < 0.001). The reduction was slightly larger with bed-time dosing (15.3 and 9.2 mm Hg reduction in the 24 h mean of systolic and diastolic BP, respectively) than with morning dosing (12.3 and 6.3 mm Hg reduction in the 24 h mean of systolic and diastolic BP, respectively). The diurnal/nocturnal ratio, measured as the nocturnal decline of BP relative to the diurnal mean, was unchanged in the group ingesting valsartan upon awakening (-1.0 and -0.3 for systolic and diastolic BP; p > 0.195). This ratio was significantly increased (6.6 and 5.4 for systolic and diastolic BP; p < 0.001) when valsartan was ingested at bed-time. The reduction of the nocturnal mean was doubled in the group ingesting valsartan at bed-time, as compared to the group ingesting it in the morning (p < 0.001). In elderly hypertensive patients, mainly characterized by a diminished nocturnal decline in BP, bed-time valsartan dosing is better than morning dosing since it improves efficacy during the nighttime sleep span, with the potential reduction in cardiovascular risk that has been associated with a normalized diurnal/nocturnal BP ratio.

Antihypertensive Agents↗

PubMed2005

Treatment of non-dipper hypertension with bedtime administration of valsartan.

BACKGROUND: Previous results have indicated that valsartan administration at bedtime, as opposed to upon wakening, may improve the diurnal: nocturnal ratio of blood pressure without loss in 24-h coverage and efficacy. OBJECTIVES: To investigate the administration time-dependent antihypertensive efficacy of valsartan in non-dipper patients. METHODS: We studied 148 non-dipper patients with grade 1-2 essential hypertension, aged 53.0+/-12.6 years, who were randomly assigned to receive valsartan (160 mg/day) as a monotherapy either on awakening or at bedtime. Blood pressure was measured every 20 min during the day and every 30 min at night for 48 consecutive hours before and after 3 months of treatment. Physical activity was simultaneously monitored every minute by wrist actigraphy to accurately calculate the diurnal and nocturnal means of blood pressure on a per subject basis. RESULTS: The significant blood pressure reduction after 3 months of valsartan (P<0.001) was similar for both treatment times (13.1 and 8.5 mmHg reduction in the 24-h mean of systolic and diastolic blood pressure with morning administration; 14.7 and 10.3 mmHg with bedtime administration; P>0.126 for treatment-time effect). The diurnal: nocturnal ratio of blood pressure was significantly increased only when valsartan was administered before bedtime, which resulted in 75% of the patients in this group reverting to dippers, a significant increase in the percentage of patients with controlled blood pressure over 24 h, and a reduction in urinary albumin excretion. CONCLUSIONS: In non-dipper hypertensive patients, dosing time with valsartan should be chosen at bedtime, for improved efficacy during the nocturnal resting hours, as well as the potential associated reduction in cardiovascular risk.

Adult↗

PubMed2004

Administration-time-dependent effects of doxazosin GITS on ambulatory blood pressure of hypertensive subjects.

Previous studies have shown that a single nighttime dose of standard doxazosin, an alpha-adrenergic antagonist, reduces blood pressure (BP) throughout the 24 h. We investigated the administration-time-dependent effects of the new doxazosin gastrointestinal therapeutic system (GITS) formulation. We studied 91 subjects (49 men and 42 women), 56.7+/-11.2 (mean+/-SD) yrs of age with grade 1-2 essential hypertension; 39 patients had been previously untreated, and the remaining 52 had been treated with two antihypertensive medications with inadequate control of their hypertension. The subjects of the two groups, the monotherapy and polytherapy groups, respectively, were randomly assigned to receive the single daily dose of doxazosin GITS (4 mg/day) either upon awakening or at bedtime. BP was measured by ambulatory monitoring every 20 min during the day and every 30 min at night for 48 consecutive hours just before and after 3 months of treatment. After 3 months of doxazosin GITS therapy upon awakening, there was a small and nonstatistically significant reduction in BP (1.8 and 3.2mm Hg in the 24 h mean of systolic and diastolic BP in monotherapy; 2.2 and 1.9mm Hg in polytherapy), mainly because of absence of any effect on nocturnal BP. The 24 h mean BP reduction was larger and statistically significant (6.9 and 5.9 mm for systolic and diastolic BP, respectively, in monotherapy; 5.3 and 4.5 mm Hg in polytherapy) when doxazosin GITS was scheduled at bedtime. This BP-lowering effect was similar during both the day and nighttime hours. Doxazosin GITS ingested daily on awakening failed to provide full 24h therapeutic coverage. Bedtime dosing with doxazosin GITS, however, significantly reduced BP throughout the 24h both when used as a monotherapy and when used in combination with other antihypertensive pharmacotherapy. Knowledge of the chronopharmacology of doxazosin GITS is key to optimizing the efficiency of its BP-lowering effect, and this must be taken into consideration when prescribing this medication to patients.

Adrenergic alpha-Antagonists↗

PubMed2004

Update in atrial fibrillation.

Atrial fibrillation (AF) is the most common sustained arrhythmia in adults. It is a significant public health problem in the United States where it affects 2.2 million Americans and almost 10% of the population older than 80 years. It should be emphasized that the prevalence of AF increases with advancing age and with worsening cardiac function. AF is an independent risk factor for death and greatly increases the risk for embolic stroke. In addition, this arrhythmia can be associated with hemodynamic instability, tachycardia-induced cardiomyopathy, and systemic embolism. The management of atrial fibrillation today is directed toward the prevention of thromboembolism, control of the ventricular rate and conversion to sinus rhythm. It is the purpose of this review to summarize the most recent information about the clinical implications and treatment of this common rhythm disorder.

Adult↗

PubMed2003

Seasonal variation of fibrinogen in dipper and nondipper hypertensive patients.

BACKGROUND: A seasonal variation with higher values in winter has been previously reported in plasma fibrinogen, a recognized marker of the potential risk of myocardial infarction and stroke. The lack of nocturnal decline in blood pressure has also been associated with an increase in cardiovascular events. Accordingly, we have compared the yearly variation of plasma fibrinogen in dipper and nondipper hypertensive patients. METHODS AND RESULTS: We studied 1006 stage 1 to 2 hypertensive patients (482 men and 524 women, 53.0+/-13.4 years of age). Blood pressure was measured every 20 minutes during the day and every 30 minutes at night for 48 consecutive hours. Physical activity was simultaneously evaluated at 1-minute intervals with a wrist actigraph. A blood sample was collected on the same day before starting blood pressure monitoring. The circannual variation of fibrinogen was established for all patients as well as for subgroups of dippers and nondippers (n=513; nocturnal blood pressure decline <10%) by multiple-component analysis. For the whole group of patients, fibrinogen was characterized by a highly significant seasonal variation (P<0.001) with a mean value of 318 mg/dL, double circannual amplitude (extent of predictable change along the year) of 40 mg/dL, and time of peak value in February. Throughout the year, the nondippers showed higher plasma fibrinogen levels than did the dippers (P<0.001). CONCLUSIONS: The elevated plasma fibrinogen levels in nondipper patients appear to be directly related to their increased risk in vascular events, which are more prominent during the late winter months.

Adult↗

PubMed2003

Administration time-dependent effects of valsartan on ambulatory blood pressure in hypertensive subjects.

This study investigated the administration time-dependent antihypertensive efficacy of valsartan, an angiotensin II receptor blocker. We studied 90 subjects (30 men and 60 women), 49.0+/-14.3 (mean+/-SD) years of age with stage 1 to 2 essential hypertension; they were randomly assigned to receive valsartan (160 mg/d) as a monotherapy either on awakening or at bedtime. Blood pressure was measured by ambulatory monitoring every 20 minutes during the day and every 30 minutes at night for 48 consecutive hours before and after 3 months of treatment. Physical activity was simultaneously monitored every minute by wrist actigraphy to accurately calculate the diurnal and nocturnal means of blood pressure on a per-subject basis. The highly significant blood pressure reduction after 3 months of treatment with valsartan (P<0.001) was similar for both treatment times (17.0 and 11.3 mm Hg reduction in the 24-hour mean of systolic and diastolic blood pressure with morning administration and 14.6 and 11.4 mm Hg reduction with bedtime administration; P>0.174 for treatment time effect). Valsartan administration at bedtime as opposed to on wakening resulted in a highly significant average increase by 6% (P<0.001) in the diurnal-nocturnal ratio of blood pressure; this corresponded to a 73% relative reduction in the number of nondipper patients. The findings confirm that valsartan efficiently reduces blood pressure throughout the entire 24 hours, independent of treatment time. They also suggest that time of treatment can be chosen according to the dipper status of a patient to optimize the effect of antihypertensive therapy, an issue that deserves further investigation.

Adult↗

PubMed2003

[Seasonal variation in plasma fibrinogen in dipper and non-dipper patients with mild-moderate essential hypertension].

BACKGROUND AND OBJECTIVE: Increased plasma fibrinogen is recognized as a significant parameter for assessing the potential risk of myocardial infarction and stroke. A seasonal variation has been reported for plasma fibrinogen, with highest values occurring in the coldest months of the year. On the other hand, the lack of nocturnal decline in blood pressure has been associated with an increase in cardiovascular events. Accordingly, we have quantified the yearly variation in plasma fibrinogen in hypertensive patients classified according to their nocturnal decline in blood pressure. PATIENTS AND METHOD: We studied 577 mild-to-moderate hypertensive patients (254 men), 53.8 13.8 years of age. Blood pressure was measured every 20 min during the day and every 30 min at night for 48 consecutive hours. Physical activity was simultaneously evaluated at 1-min intervals with a wrist actigraph. A complete blood test was performed on the same day before starting blood pressure monitoring. The circannual variation of plasma fibrinogen was established for all patients as well as for subgroups of dippers (n = 287) and non-dippers (n = 290; patients with a nocturnal blood pressure decline < 10% of the diurnal mean) by multiple-component analysis. RESULTS: For the whole group of hypertensive patients, plasma fibrinogen was characterized by a highly significant seasonal variation (p < 0.001), with a mean value of 324 mg/dl, double circannual amplitude (i.e, extent of predictable change along the year) of 75 mg/dl, and time of peak value on the first week of March. This circannual variation can be best represented by a model that includes components with periods of 12 and 6 months. The same model also characterized dippers as well as non-dippers, analyzed separately. Non-dippers showed higher plasma fibrinogen throughout the whole year as compared to dippers (p = 0.002). CONCLUSIONS: The elevation of plasma fibrinogen in non-dipper patients as compared to dippers could support the association between the lack of nocturnal decline in blood pressure with an increase in cardiovascular events, since the circannual variation in fibrinogen is timely correlated with the reported yearly variation in coronary events.

Adult↗

PubMed2003

[Administration-time dependent effects of acetyl-salicylic acid on blood pressure in patients with mild essential hypertension].

BACKGROUND AND OBJECTIVES: Previous studies on the potential influence of aspirin (AAS) on blood pressure have not taken in consideration the chronopharmacologic effects of non-steroidal antiinflammatory drugs. This pilot study investigated the effects of AAS on blood pressure in hypertensive patients under no antihypertensive treatment who received AAS at different day times according to their rest-activity cycle. PATIENTS AND METHOD: We studied 64 untreated patients with mild hypertension (24 men), 43.5 (12.0) (mean [SD]) years of age, randomly divided in 3 groups: group 1, non-pharmacological hygienic-dietetic recommendations; group 2, the same recommendations plus AAS (100 mg/day) on awakening, and group 3, the same recommendations plus AAS (100 mg/day) before bedtime. Blood pressure was measured every 20 min during the day and every 30 min at night for 48 consecutive hours before and after 3 months of intervention. The circadian pattern of blood pressure in each group was established by population multiple-component analysis. Circadian parameters obtained for each group of patients before and after the intervention were compared with a nonparametric paired test. RESULTS: After 3 months of non-pharmacological intervention, there was a small and non-significant reduction of blood pressure (< 1.5 mmHg; p = 0.28). There was no change in blood pressure when AAS was given on awakening (p = 0.21). A highly significant blood pressure reduction was, however, observed in patients who received AAS before bedtime (decrease of 7 and 5 mmHg in systolic and diastolic blood pressure, respectively; p = 0.006). CONCLUSIONS: Our results indicate a statistically significant time-dependent administration effect of low-dose AAS on blood pressure in untreated patients with mild hypertension. This effect reinforces the need to quantify and control AAS effects in patients using this agent in combination with antihypertensive agents.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed2003

Administration time-dependent effects of aspirin on blood pressure in untreated hypertensive patients.

Previous studies on the potential influence of aspirin on blood pressure have not taken into consideration the chronopharmacological effects of nonsteroidal anti-inflammatory drugs. This pilot study investigates the effects of aspirin on blood pressure in untreated hypertensive patients who received aspirin at different times of the day according to their rest-activity cycle. We studied 100 untreated patients with mild hypertension (34 men and 66 women), 42.5+/-11.6 (mean+/-SD) years of age, randomly divided into 3 groups: nonpharmacological hygienic-dietary recommendations; the same recommendations and aspirin (100 mg/d) on awakening; or the same recommendations and aspirin before bedtime. Blood pressure was measured every 20 minutes during the day and every 30 minutes at night for 48 consecutive hours before and after 3 months of intervention. The circadian pattern of blood pressure in each group was established by population multiple-component analysis. After 3 months of nonpharmacological intervention, there was a small, nonsignificant reduction of blood pressure (<1.1 mm Hg; P>0.341). There was no change in blood pressure when aspirin was given on awakening (P=0.229). A highly significant blood pressure reduction was, however, observed in the patients who received aspirin before bedtime (decrease of 6 and 4 mm Hg in systolic and diastolic blood pressure, respectively; P<0.001). Results indicate a statistically significant administration time-dependent effect of low-dose aspirin on blood pressure in untreated patients with mild hypertension. The influence of aspirin on blood pressure demonstrated in this study indicates the need to quantify and control for aspirin effects in patients using this drug in combination with antihypertensive medication.

Adult↗

PubMed2003

The 'ABPM effect' gradually decreases but does not disappear in successive sessions of ambulatory monitoring.

OBJECTIVES: Previous results have indicated that ambulatory monitoring provides a pressor effect on patients using the device for the first time, but not on successive sessions of monitoring. Our objective was to validate and quantify the extent and duration of this pressor effect in hypertensive patients repeatedly evaluated every few months. METHODS: We studied 823 mild-to-moderate hypertensive subjects (347 men), 53.4 +/- 14.1 years of age. Blood pressure was measured at 20-min intervals during the day and at 30-min intervals at night for 48 consecutive hours, and physical activity was simultaneously evaluated every minute with a wrist actigraph. Forty per cent of the patients were evaluated twice or more. RESULTS: In patients evaluated for the first time, results indicated a highly statistically significant (P < 0.001) reduction during the second day of monitoring as compared to the first in the diurnal mean of systolic and diastolic blood pressure, but not in heart rate or physical activity. This pressor effect remained statistically significant for the first 10 h of monitoring, independent of gender, day of the week of monitoring, or number of antihypertensive drugs used by the patients. The nocturnal mean of blood pressure was, however, similar between both days of sampling. This 'ambulatory monitoring effect' was diminished, although not eliminated, in extent and duration for successive sessions of ambulatory monitoring. CONCLUSIONS: Ambulatory monitoring for 48 h revealed a statistically significant pressor response that could mostly reflect a novelty effect in the use of the monitoring device. This effect has marked implications in both research and clinical daily practice for a proper diagnosis of hypertension and evaluation of treatment efficacy by the use of ambulatory monitoring.

Adolescent↗

PubMed2002

Evaluation of the extent and duration of the "ABPM effect" in hypertensive patients.

OBJECTIVES: The goal of this study was to test and quantify the extent and duration over time of a possible pressor effect due to ambulatory monitoring. BACKGROUND: The use of ambulatory blood pressure monitoring has provided a method of blood pressure (BP) assessment that compensates for some of the limitations of office values. While a "white-coat" pressor effect on conventional measurements has been defined and frequently used for the improved evaluation of hypertensive patients, there has not been clear indication that the ambulatory technique could also influence BP. METHODS: We studied 538 mild-to-moderate hypertensive patients (233 men), 54.2 +/- 14.2 (mean +/- SD) years of age. Blood pressure and heart rate were measured at 20-min intervals during the day and at 30-min intervals at night for 48 consecutive hours, and physical activity was simultaneously evaluated at 1-min intervals with a wrist actigraph. One-third of the patients were evaluated twice or more times. RESULTS: In both treated and untreated hypertensive patients evaluated for the first time, results indicate a statistically significant (p < 0.001) reduction during the second day of monitoring as compared with the first in the diurnal mean of systolic and diastolic BP, but not in heart rate or physical activity. This pressor effect remains statistically significant for the first 6 h to 8 h of monitoring independently of gender, days of the week of monitoring or number of antihypertensive drugs used by the treated patients. The nocturnal mean of BP was, however, similar between both days of sampling. This "ambulatory monitoring effect" was not observed when the patients were evaluated after the same sampling scheme for the second or successive times three months apart. CONCLUSIONS: Ambulatory monitoring for 48 consecutive hours reveals a statistically significant pressor response that could reflect a novelty effect in the use of the monitoring device for the first time. This effect has marked implications in both research and clinical daily practice for a proper diagnosis of hypertension and evaluation of treatment efficacy by the use of ambulatory monitoring.

Adult↗

PubMed2002

Relationship between physical activity and blood pressure in dipper and non-dipper hypertensive patients.

BACKGROUND: The lack of nocturnal decline in blood pressure has been associated with an increase in end-organ damage and cardiovascular events, although results remain controversial, partly because of the inability to reproduce correctly, over time, the classification of patients into dippers and non-dippers. Moreover, the non-dipping status has been frequently related to an increase in nocturnal activity, differences in quality of sleep, or both. OBJECTIVE: To assess the relationship between activity and blood pressure in patients with hypertension. METHODS: We studied 306 mild-to-moderately hypertensive patients (130 men), 53.7 +/- 14.0 years of age (mean +/- SD). Blood pressure and heart rate were measured for 48 consecutive hours, at 20-min intervals during the day and at 30-min intervals at night, using an ambulatory device, and physical activity was simultaneously evaluated at 1-min intervals by wrist actigraphy. Circadian parameters of blood pressure, heart rate and activity established by population multiple-components analysis were compared between dippers and non-dippers, by non-parametric testing. Diurnal and nocturnal means of blood pressure and activity were computed for each patient according to individual resting hours determined by actigraphy, and compared among groups by analysis of variance. RESULTS: Despite highly statistically significant differences between dippers and non-dippers with respect to nocturnal means and in each hourly nightly mean of blood pressure, there were no differences between them for the same parameters during activity, whether or not the patients were receiving medication at the time of monitoring. The average duration of sleep and the 24-h mean and standard deviation of activity were also similar between the groups. CONCLUSIONS: The highly significantly different circadian variation in blood pressure between dippers and non-dippers with essential hypertension is not related to a significant increase in nocturnal physical activity. Differences in blood pressure could, however, be related to the absence of 24-h therapeutic coverage in most non-dipper patients receiving antihypertensive medication.

Adult↗