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Biomedical subjects

G A Mansoor

Publications and source records attributed to G A Mansoor.

At least 19 recordsLinked to original sources
PubMed2002

Sleep actigraphy in hypertensive patients with the 'non-dipper' blood pressure profile.

Several prospective studies have demonstrated a higher cardiovascular complication rate in patients with a non-dipping compared with a dipping blood pressure profile. However, the extent of blood pressure reduction during sleep can be highly variable in an individual patient, and a repeat ambulatory blood pressure study commonly shows a change in category. The reasons for this variability are not clear. In general, hypertensive patients with a non-dipper blood pressure profile have higher actigraphy-measured activity during time in bed than dipper hypertensive patients but no analysis of actigraphy-determined sleep parameters has been published. We therefore prospectively studied 52 hypertensive patients who were off antihypertensive drugs for at least 3 weeks and who underwent simultaneous ambulatory and wrist actigraphy monitoring. All patients were clinically free of any sleep-related disorder. The blood pressure profile was labelled dipper when the change in mean awake blood pressure to sleep blood pressure was 10% or higher and non-dipper if less than 10%. Overall activity levels were higher during the time in bed in the non-dipper group compared with the dipper group. An inverse relationship of daytime activity with age was seen in men (r = -0.54, P = 0.001) but not in women (r = -0.06, P = 0.79). Both groups of hypertensive patients had a similar total time in bed (458 +/- 92 min, in dippers and 433 +/- 106 min in non-dippers, P = 0.39). Sleep latency (time to onset of sleep after getting into bed) was a median of 7 min in dippers and 15 min in non-dippers (P = 0.10). In addition, dipper hypertensives spent more of the time in bed asleep than non-dippers (87% vs 76%, P = 0.004). Logistic regression analysis revealed that body mass index, kg/m(2) (OR, 1.3), and night-time activity (units/min) (OR, 1.1) were predictive of a non-dipping blood pressure profile. These data show a possible disturbance of sleep in non-dipper hypertensive patients.

Aged↗
PubMed2001

Herbs and alternative therapies in the hypertension clinic.

The use of alternative therapies, herbs, and supplements occurs at a very high rate among patients attending a variety of health care settings. Such therapy may cause significant interactions or effects on hypertension and other cardiovascular disorders and needs to be considered by clinicians. In this brief review, we highlight several commonly used alternative therapies that may have a clinical impact in the hypertensive patient. Several problems hinder our complete awareness of these effects. These problems include patients not informing physicians about alternative treatment or herbal use, the lack of consistent scientific standards for the bioactivity of many herbals or supplements, and the multiple names that each bioactive substance is sold under. Specific questioning regarding herbals and alternative therapies in the hypertension clinic is therefore needed. Herbals including ma huang, St. John's wort, yohimbine, garlic, and licorice all may cause important consequences in the hypertensive patient. Added care is needed in monitoring the use and effects of herbal and alternative therapies in the hypertensive population.

Ambulatory Care Facilities↗
PubMed2001

Evaluation of the 24-hour blood pressure effects of eprosartan in patients with systemic hypertension.

BACKGROUND: Eprosartan is a new nonphenyl angiotensin II receptor blocker, which has been approved for the treatment of hypertension. Although the drug has a relatively short plasma half-life of 5 to 9 h, clinical studies have suggested that its antihypertensive effect persists for 24 h. METHODS: We assessed both the changes in 24-h and trough blood pressure (BP) (last 4 h of the ambulatory BP while the patient was awake) of eprosartan at doses of 600 and 1,200 mg once daily in a randomized, double-blind, placebo-controlled trial. Ambulatory BP was monitored at placebo baseline and after 8 weeks of double-blind therapy. RESULTS: Two hundred patients randomized in the study with 177 patients completing the trial. The 24-h change in BP from baseline was 0.2/0.1 +/- 1.4/1.0 mm Hg, -7.9/ -5.4 +/- 1.0 mm Hg (P < .0001), and -7.4/-5.0 +/- 0.9 mm Hg (P < .0001) in the placebo, 600-mg eprosartan, and 1,200-mg eprosartan groups, respectively. Changes in trough ambulatory BP showed significant reductions of -6.3/-4.1 +/- 1.6/1.1 mm Hg and -7.7/-5.5 +/- 1.5/1.0 mm Hg for 600 mg of eprosartan and 1,200 mg of eprosartan, respectively. CONCLUSIONS: These data demonstrate that eprosartan at doses of 600 or 1200 mg significantly reduced BP throughout an entire 24-h dosing period. There were no differences between the 600- and 1,200-mg dose; thus, 600 mg once daily should be the only dose used in the treatment of hypertension with eprosartan.

Acrylates↗
PubMed2000

The relationship of electronically monitored physical activity to blood pressure, heart rate, and the circadian blood pressure profile.

We studied how closely changes in electronically monitored physical activity are reflected in changes in blood pressure and heart rate in a group of untreated hypertensive subjects. Thirty-nine hypertensive patients (office blood pressure > 140/ 90 mm Hg) of mean age 57 +/- 10 years (mean +/-SD) wore an ambulatory blood pressure monitor and a wrist actigraph simultaneously. Both average and peak activity for 5 min before each valid blood pressure reading were determined, as was average activity for awake and sleep periods, determined by patient kept diaries. For the overall group, awake and 24-h activities were inversely correlated to age (n = 39, r = -0.42; P = 0.01 and n = 39, r = -0.38; P = 0.01, respectively). No correlation was found between group awake activity and group-average blood pressure or heart rate. For individual patients, there was marked variation in the degree of correlation between awake activity measures (both peak and average) and blood pressure and heart rate. The strongest positive correlation was between activity levels and the heart rate-pressure product. Nondipper profile hypertensives had higher sleep activity than dipper hypertensives (44 +/- 28 units/min v 25 +/- 20 units/min, df = 37, t = 2.12; P = 0.04), but awake activity levels were similar. The higher sleep activity remained after adjustment for age. These findings indicate that the relationship between actigraphic activity and hemodynamic parameters is highly variable and that the rate-pressure product is the strongest correlate of short-term activity. Furthermore, hypertensives with the nondipper profile have higher sleep activity than dipper hypertensives. These findings stress the need for further study into the role of day-to-day activity in determining ambulatory blood pressure and heart rate variability.

Activities of Daily Living↗
PubMed2000

Coexistence of atherosclerotic renal artery stenosis with primary hyperaldosteronism.

The discovery of two forms of secondary hypertension in the same patient is unusual and suggests similar pathophysiological mechanisms, a predisposition to one type in the presence of the other or a chance occurrence. We describe two patients with renal artery stenosis who after successful correction of the stenotic lesions were discovered to have primary hyperaldosteronism associated with bilateral adrenal hyperplasia. Initially prior to revascularisation of the renal artery stenosis, the diagnosis of primary hyperaldosteronism was not evident. Both patients were subjected to further diagnostic evaluation after the appearance of hypokalaemia in one patient and continued resistant hypertension in both patients. The addition of spironolactone therapy reduced blood pressure impressively in both patients. Clinicians should be aware of the possibility that these two forms of secondary hypertension may be present in the same patient and that optimal blood pressure control requires diagnostic assessment and intervention for both disorders.

Aged↗
PubMed2000

Reproducibility of ambulatory blood pressure monitoring in hemodialysis patients.

Ambulatory blood pressure monitoring (ABPM) has been increasingly used in hemodialysis (HD) practice and research; however, no study has evaluated the reproducibility of ABPM in this population. To address this question, we performed 48-hour interdialytic ABPM on 21 HD patients (mean age, 53 +/- 16 years; 7 women) on two different occasions 68 +/- 34 days (range, 30 to 154 days) apart. To qualify for the protocol, patients had to be at the same dry weight and on the same vasoactive drug regimen at both monitoring periods. BP was analyzed according to three different methods: isolated pre-HD and post-HD values, average pre-HD and post-HD values for the five HD sessions surrounding each monitoring period, and 48-hour interdialytic ABPM. Reproducibility was determined by analysis of the SD of the differences (SDD) between the two monitoring periods and the coefficient of variation of each method of BP determination. Our results show better reproducibility of ABPM (SDD, 10.6/6.6 mm Hg; coefficient of variation, 7.5%/8.1%) compared with isolated pre-HD BP (SDD, 24.4/11.3 mm Hg; coefficient of variation, 16.7%/14.1%) or post-HD BP (SDD, 16.8/14.5 mm Hg; coefficient of variation, 11.7%/17.8%), and averaged pre-HD BP (SDD, 14.7/7.2 mm Hg; coefficient of variation, 10.1%/9.1%) or post-HD BP (SDD, 12.4/8.7 mm Hg; coefficient of variation, 8.9%/11.1%). The reproducibility of the decrease in BP during sleep was poor, with up to 43% of the subjects changing dipping category within or between interdialytic periods. We conclude that ABPM is the most accurate method to study BP in HD patients over time. However, variability is significant, and there is poor reproducibility of the nocturnal decline in BP.

Blood Pressure↗
PubMed1999

Web Alert.

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Cardiovascular Diseases↗
PubMed1999

Differential effects of morning and evening dosing of nisoldipine ER on circadian blood pressure and heart rate.

The time of administration of once-daily antihypertensive agents may have a significant impact on blood pressure control during awake and sleep periods. Using 24-h ambulatory monitoring, we compared the effects of morning and evening dosing of the long-acting dihydropyridine calcium channel blocker, nisoldipine extended-release (ER), on circadian blood pressure (BP) and heart rate in patients with mild-to-moderate hypertension. After completing a 3-week placebo run-in period, 85 patients were randomized to morning versus evening nisoldipine ER treatment at a fixed 20-mg dose. Patients were treated for 4 weeks, followed by crossover to the alternate dosing regimen for 4 additional weeks. Twenty-four-hour ambulatory monitoring was performed at baseline and at 4 and 8 weeks after randomization. Awake and sleep times were determined by electronic activity recorders (Actigraphy). Similar least-squares (+/-SE) mean changes from baseline in 24-h BP (systolic BP/diastolic BP: -11.9/-7.4 +/- 0.6/0.5 v -11.6/-6.5 +/- 0.6/0.5 mm Hg) and heart rate (1.0/1.7 +/- 0.4/0.4 beats/min) occurred with morning and evening administration, respectively. A significantly greater effect on awake diastolic BP (systolic BP/diastolic BP: -12.6/-8.1 +/- 0.7/0.4 v -11.3/-6.4 +/- 0.7/0.4 mm Hg; P = .16/.01) was observed with morning dosing compared with evening dosing. In addition, small increases in sleep and early morning heart rate were seen with evening compared with morning administration of nisoldipine (sleep, 3.1 +/- 0.4 v 0.4 +/- 0.4 beats/min; P < .001; early morning, 3.5 +/- 0.7 v 0.5 +/- 0.7 beats/min; P = .002). These differential effects on awake BP and sleep heart rate were also observed in patients who had normal (dippers) and elevated (nondippers) BP values during sleep. Appropriate evaluation of the efficacy and safety of long-acting antihypertensive agents is essential when evening administration is being considered. In the present study, the timing of nisoldipine ER administration had no effect on mean changes in BP and heart rate over a 24-h period. However, nisoldipine ER had some differential effects during sleep and awake periods with morning relative to evening dosing.

Antihypertensive Agents↗
PubMed1999

Task force VI: Self-monitoring of the blood pressure.

BACKGROUND: Self-monitoring of the blood pressure by patients at home or in other nonclinical settings has become increasingly common in recent years. This phenomenon has been fueled in part by the increase in availability of automatic sphygmomanometers, which are now both affordable and easy for patients to use. BENEFITS OF SELF-MONITORING: Self-monitoring of the blood pressure can be an important adjunct to management of hypertension. The technique allows patients to participate more in their care. Self-measured values of blood pressure are more likely to be representative of the average daily blood pressure than is a clinic measurement and may be better related to hypertensive involvement of target organs and cardiovascular morbidity than is the clinic blood pressure. Finally, the self-monitoring of blood pressure has the potential to reduce the costs of hypertension-related care. LIMITATIONS OF SELF-MONITORING: There are several issues that prevent the more widespread use of self-monitoring of the blood pressure in clinical practice. First, devices marketed for use by patients have advanced technically during the 1990s, but many have not been subjected to rigorous clinical validation for precision and reliability (e.g. in terms of Association for the Advancement of Medical Instrumentation and British Hypertension Society guidelines). It is recommended that devices for measuring blood pressure used by patients at home be subjected to the same validation processes as those that are applied to ambulatory recordings. Second, although the upper limits of normal for self-monitored blood pressure of a general population can be defined statistically (it is approximately 135/85 mmHg), it is not yet possible to determine the normal self-monitored blood pressure because these values must be linked to classical clinical cardiovascular endpoints or outcomes. Third, the relationships among self-monitored, clinic, and ambulatory blood pressures are defined for some populations but their behaviors according to age, sex, ethnicity, and treatment status require further study. Fourth, several different schedules for self-monitoring of the blood pressure by patients have been used in clinical research and practice. It will be necessary to determine the optimal schedule and number of recordings required when patients perform self-monitoring of the blood pressure. Fifth, self-monitoring of the blood pressure in clinical trials of antihypertensive therapies is certainly feasible but has typically not been included in their design, either by investigators or by the pharmaceutical sponsors. Sixth, there have been data suggesting that self-monitoring of the blood pressure reduces the comprehensive costs associated with hypertension care on an annual basis. However, since most work on the economic impact of self-monitoring of the blood pressure has been performed in managed-care environments in the USA, it is not known whether this reduction in health-care costs would be applicable to other types of practice environments on a worldwide basis. CONCLUSIONS: Self-monitoring of the blood pressure is at present useful as an adjunct measurement for the management of hypertensive patients and might provide benefits in clinical trials of antihypertensive therapy. Nevertheless, the available data on self-monitoring of the blood pressure are inadequate as grounds for clinicians to make primary diagnostic or therapeutic decisions and should not override the blood pressure obtained by clinical measurement or via ambulatory monitoring.

Blood Pressure↗
PubMed1999

Left ventricular hypertrophy: a potent cardiovascular risk factor and its relationship to office and ambulatory blood pressure.

Left ventricular hypertrophy (LVH) is an important cardiovascular risk factor. The presence of LVH carries risk independent of hypertension. LVH can be detected non-invasively using electrocardiography or echocardiography. Clinical studies have consistently shown that ambulatory blood pressure is a stronger correlate of left ventricular mass than office blood pressure. Furthermore, treatment-induced decreases in left ventricular mass index are also more tightly related to reductions in ambulatory blood pressure than reductions in office blood pressure. The primary intervention for subjects with hypertension and LVH is optimal blood pressure control. Several small studies now suggest that therapeutic changes resulting in regression of left ventricular mass also confer a reduction in cardiovascular risk. Therefore, LVH is a serious negative risk factor that is more closely related ambulatory rather than office blood pressure. Fortunately, current evidence suggests that optimal antihypertensive therapy resulting in regression of hypertrophy will reduce at least short-term cardiovascular events. Physicians need to be more aware of LVH as a cardiovascular risk factor.

Blood Pressure↗
PubMed1998

Circadian blood pressure variation in hypertensive patients with primary hyperaldosteronism.

A less-than-normal decline in nocturnal blood pressure (BP) has been associated with excessive hypertensive complications. This is concerning because secondary hypertension is often associated with this so-called nondipper BP profile. A nondipping pattern is more frequently found in the presence of pheochromocytoma, Cushing's syndrome, and sleep apnea syndrome, but the prevalence is unclear in patients with primary hyperaldosteronism. We therefore studied ambulatory BP profiles in 16 hypertensive patients with primary hyperaldosteronism and an equal number of essential hypertensive subjects. The awake-sleep BP difference of the hyperaldosteronism patients was similar to that of essential hypertensives (15/14 +/- 3/2 versus 14/9 +/- 3/2 mm Hg, P=NS). The prevalence of dippers and nondippers (according to two distinct criteria) in the two groups was similar. Repeat ambulatory BP monitoring in 12 subjects with primary hyperaldosteronism after specific intervention (3 after surgical removal of an adrenal adenoma and 9 after commencement and titration of spironolactone therapy) showed highly significant reductions in office BP (22/10 +/- 6/4 mm Hg, P<.05) and awake and sleep BP. However, the extent of nocturnal BP decline was unchanged between the two studies (17/16 +/- 3/3 versus 16/12 +/- 2/2 mm Hg, P=NS). There was no correlation between the awake-sleep difference and serum or urinary aldosterone levels or the aldosterone-to-renin ratio. In this study, we did not detect any differences in the awake-sleep differences between a group of hypertensives with primary hyperaldosteronism and a control group of essential hypertensives.

Adult↗
PubMed1997

Ambulatory blood pressure monitoring is a useful clinical tool in nephrology.

Hypertension is a key factor in the genesis and deterioration of many renal diseases and is also a risk factor for death in patients with end-stage renal disease. However, the standard methods of measurement are prone to variability, especially in patients undergoing dialysis. The technique of ambulatory blood pressure monitoring allows a better assessment of overall blood pressure levels and promises to assume a bigger role in the care of renal patients. Ambulatory blood pressure monitoring is widely used in hypertension trials, and the reports of several consensus meetings on the clinical uses of ambulatory blood pressure monitoring have been published. Two similar validation protocols now exist for ambulatory blood pressure monitors, and tables of population-based normal blood pressures for age and gender are available. The available evidence suggests that ambulatory blood pressure compared with blood pressure measured in the physician's office is better correlated to left ventricular mass in subjects with chronic renal disease. Furthermore, studies in subjects with chronic renal disease and those undergoing renal replacement therapy show that blood pressure control is suboptimal in many patients and that nocturnal blood pressure is generally higher than in control subjects. Further insights into overall blood pressure behavior in this population will certainly emerge in the future.

Blood Pressure↗
PubMed1996

"Inappropriate" physician habits in prescribing oral nifedipine capsules in hospitalized patients.

Despite the absence of an approved Food and Drug Administration (FDA) indication, the use of oral or "sublingual" nifedipine for hypertension in the hospitalized patient has become an increasingly common practice. The purpose of the study was to assess the clinical circumstances for which the drug was being prescribed and the practices of attending and resident physicians. Dosing of oral nifedipine capsules in medical and surgical inpatients was studied prospectively in three central Connecticut hospitals (University, community-teaching, and private nonteaching) during a 60-day period from January to March, 1994. Through evaluation of computerized pharmacy and medical records, data were collected on diagnostic reasons for ordering nifedipine, pre- and posttreatment blood pressures, dosing frequency, clinical documentation associated with drug prescription, and adverse events. Physicians and nurses at the respective hospitals were unaware of the conduct of the study. The incidence of nifedipine capsule administration at all three hospitals was 3.4% (152 dosings in 83 patients/4489 hospitalized patients/ 60 days). Practice habits and blood pressure changes differed minimally among hospitals and physicians. Sixty-three percent of nifedipine orders were given over the telephone for arbitrary and asymptomatic blood pressure elevations and 98% of the orders lacked bedside patient evaluation. Follow-up of the blood pressure was performed within 1 h in 51% of patients and within 2 h in 24%, while in 25% there was no documentation of follow-up until 2 to 6 h after nifedipine dosing. Mean pretreatment blood pressure was 186/94 +/- 20/16 mm Hg (range: 150 to 260 mm Hg systolic and 50 to 125 mm Hg diastolic). Blood pressure fell 32/16 +/- 22/16 mm Hg (range: -92 to +8 mm Hg systolic and -90 to +28 mm Hg diastolic) and was related to the level of pretreatment blood pressure (r = 0.53 for systolic blood pressure, and r = 0.49 for diastolic blood pressure, P < .001 for both). Large, asymptomatic blood pressure reductions were common. One hypertensive patient experienced severe hypotension accompanied by an anterior wall myocardial infarction. These data demonstrate inappropriate physician prescribing of oral nifedipine in hospitalized patients characterized by a lack of proper assessment prior to drug dosing, highly arbitrary treatment parameters that were written without regard for symptoms or underlying illnesses, and slow follow-up for evaluation of the clinical response to therapy.

Administration, Oral↗
PubMed1996

Determinants of the white-coat effect in hypertensive subjects.

To determine the magnitude and the relationships of the difference between office and awake ambulatory blood pressures (BP) (white-coat effect) in ambulatory hypertensive patients, 64 consecutive patients referred to the ambulatory BP monitoring laboratory were studied. All subjects were evaluated prospectively by study nurse, study doctor, and ambulatory BP measurements. Order of measurements was randomized and observers were blinded to each others readings. No differences were found in the white-coat effects among study nurse (22/14 +/- 20/9 mm Hg), study doctor (27/12 +/- 20/10 mm Hg) and referring doctor (19/11 +/- 18/10 mm Hg). Similarly, female and male patients exhibited similar white-coat effects on the day of ambulatory monitoring. Older patients (> or = 65 years) displayed higher mean systolic white-coat effects than younger patients (29 +/- 18 mm Hg vs 19 +/- 19 mm Hg, P = 0.04). Multivariate analysis using the mean average systolic white-coat effect as the dependent variable and age, gender, treatment status, body mass index (BMI) and duration of hypertension as independent variables showed a significant independent role for age. In contrast, no clinical correlates of the diastolic white-coat effect were found. Older patients are more likely to display a systolic white-coat effect in the medical care environment.

Age Factors↗
PubMed1995

Effects of actual versus arbitrary awake and sleep times on analyses of 24-h blood pressure.

Investigators conducting hypertension trials with ambulatory blood pressure (BP) monitoring have been analyzing study results using arbitrary times for day (wakefulness) and night (sleep). We prospectively evaluated the impact of using arbitrary times instead of patient reported awake and sleep times on mean 24-h, awake, and sleep BP, BP loads, and the awake-sleep BP difference in 50 subjects. Daytimes and nighttimes were derived from popular, arbitrary times reported in the literature. Compared to actual awake and sleep periods, arbitrary day and night division caused no significant differences in the mean awake and sleep BPs. However, limits of agreement for BP values derived for the actual and arbitrary times of wakefulness and sleep were substantial especially during sleep (awake systolic BP, -4 to 7 mm Hg; awake diastolic BP, -2 to 4 mm Hg; sleep systolic BP, -12 to 7 mm Hg; and sleep diastolic BP -7 to 4 mm Hg). Sleep BP loads (proportion of BPs > 120/80 mm Hg) were altered by greater than 10% in 20% to 30% of the subjects, depending on choice of time schedule. These data demonstrate that the calculation of BP and BP load during sleep may be altered by use of arbitrary, rather than actual, times of wakefulness and sleep in 24-h studies of ambulatory BP.

Analysis of Variance↗