Gary D. James

The reproducibility of average ambulatory, home, and clinic pressures.

The reproducibility of ambulatory, home, and clinic blood pressures was compared in 13 untreated mildly hypertensive and 14 normotensive subjects. Each subject had two sets of daily ambulatory recordings, home self-measured readings (over 6 days), and clinic measurements taken 2 weeks apart. Comparisons over the 2 weeks within and among the methods of measurements were made using a repeated-measures analysis of variance. The results showed that there was no consistent average change in the ambulatory or home pressures and no change in clinic diastolic pressures, but the clinic systolic pressure of the hypertensive subjects dropped 6 mm Hg (p less than 0.05), while that of the normotensive subjects showed no significant change. Test-retest correlations of each of the three methods were similar in magnitude, indicating a similar level of reliability. Test-retest correlations of the ambulatory standard deviations, however, were low, indicating a low reliability of this measure of daily pressure variability. These results suggest that the reproducibility of ambulatory pressures may be as good or better than that of home or clinic measurements. They also suggest that the average ambulatory pressure may be preferable as the measurement in clinical trials, since it may be less influenced by measurement anxiety, particularly in hypertensive subjects.

The influence of happiness, anger, and anxiety on the blood pressure of borderline hypertensives.

&NA; Differences in blood pressure associated with reported happiness, anger, and anxiety are examined among 90 borderline hypertensives during 24‐hr blood pressure monitoring. There were 1152 individual ambulatory blood pressure readings for which subjects classified their emotional state as happy (n = 628), angry (n = 67), or anxious (n = 457) on scales from one (low) to ten (high). Pressures were transformed to z‐scores using the subjects 24‐hr mean and standard deviation to assess relative elevation during reported emotional arousal. The results show that emotional arousal significantly increases systolic and diastolic pressure (p less than 0.00001), an effect independent of posture and location of subject during measurement (at work, home, or elsewhere). On average, pressures during reported angry or anxious states were higher than those during a happy state (p less than 0.01). Examination of arousal intensity showed that scores on the happiness scale were inversely related to systolic pressure (p less than 0.01) whereas the degree of anxiety was positively associated with diastolic pressure (p less than 0.02). Emotional effects were also related to the degree of individual daily pressure variation such that the greater the variability, the larger the blood pressure change associated with the emotions. The results suggest that happiness, anger, and anxiety increase blood pressure to differing degrees and that emotional effects may be greater in individuals with more labile blood pressure.

Ambulatory blood pressure in normotensive and hypertensive subjects: Results from an international database

Objective To delineate more precisely an operational threshold for making clinical decisions based on ambulatory blood pressure (ABP) measurement by studying the ABP in subjects who were diagnosed as either normotensive or hypertensive by conventional blood pressure (CBP) measurement. Subjects: Twenty-four research groups recruited 7069 subjects. Of these, 4577 were normotensive (CBP 140/90 mmHg), 719 were borderline hypertensive (systolic CBP 141–159 mmHg or diastolic CBP 91–94 mmHg) and 1773 were definitely hypertensive. Of the subjects in the last of these categories, 1324 had systolic hypertension (systolic CBP 21 60 mmHg) and 131 0 had diastolic hypertension (diastolic CBP 295 mmHg). Combined systolic and diastolic hypertension was present in 861 subjects. Hypertension had been diagnosed from the mean of two to nine (median two) CBP measurements obtained at one to three (median two) visits. Results The 95th centiles of the ABP distributions in the normotensive subjects were (systolic and diastolic, respectively) 133 and 82 mmHg for 24-h ABP, 140 and 88mmHg for daytime ABP and 125 and 76mmHg for night-time ABP, respectively. Of the subjects with systolic hypertension, 24% had 24-h systolic ABP 4 33 mmHg. Similarly, 30% of those with diastolic hypertension had 24-h diastolic ABP 432 mmHg. The probability that hypertensive subjects had 24-h ABP below these thresholds tended to increase with age and was two- to fourfold greater if the CBP of the subject had been measured at only one visit and if fewer than three CBP measurements had been averaged for establishing the diagnosis of hypertension. By contrast, for each 1 O-mmHg increment in systolic CBP, this probability decreased by 54% for 24-h systolic ABP and by 26% for 24-h diastolic ABP, and for each 5-mmHg increment in diastolic CBP it decreased by 6 and 9%, respectively. In comparison with 24-h ABP, the overlap in the daytime and night-time ABP between normotensive and hypertensive subjects was of similar magnitude and was influenced by the same factors. Conclusions The ABP distributions of the normotensive subjects included in the present international database were not materially different from those in previous reports in the literature. One-fifth to more than one-third of hypertensive subjects had an ABP which was below the 95th centile of the ABP of normotensive subjects, but this proportion decreased if the hypertensive subjects had shown a higher CBP upon repeated measurement. The prognostic implications of elevated CBP in the presence of normal ABP remain to be determined.

Ambulatory blood pressure and prognosis.

Prognostic information: Ambulatory blood pressure monitoring provides three kinds of information, all of which might have prognostic significance: blood pressure level, amplitude of diurnal variation and short-term variability. Blood pressure level: Existing data support the hypothesis that patients whose ambulatory blood pressure is low in comparison with clinic blood pressure (white-coat hypertension) have a relatively low risk of morbidity. Amplitude of diurnal rhythm of blood pressure: While there is limited support for the hypothesis that patients with small diurnal variations may carry a higher risk (particularly women), opposing hypotheses are also plausible. Short-term blood pressure variability: It is hypothesized that increased variability will be associated with increased morbidity. Preliminary data from the Cornell prospective study are consistent with this hypothesis.

Comparison of self-reported smoking and urinary cotinine levels in a rural pregnant population.

OBJECTIVES (a) to assess the accuracy of self-reported smoking status in pregnant women from rural and small metropolitan statistical areas who stated they were smokers at the onset of pregnancy, (b) to compare the characteristics of these women who self-reported a nonsmoker status at the first prenatal visit with those who reported a smoker status, and (c) to determine the characteristics that predict self-reported smoking status and positive/negative urinary cotinine assays. SETTING Seven private obstetric offices serving rural and small metropolitan statistical areas in upstate New York. PARTICIPANTS A convenience sample of 94 pregnant women who stated they were smokers at the onset of their pregnancies. Their mean age was 23 years and mean level of education was 11.9 years; 95% were White, 65% were single, and 65% were Medicaid-funded. DESIGN Descriptive correlational design. At the first prenatal visit, the sensitivity and specificity of smoking and nonsmoking status were determined by comparing self-reports of smoking status with urinary cotinine assays. Data were also analyzed for relationships among demographic variables and for predictors of smoking status and urinary cotinine. RESULTS The discordance rate between self-reports of smoking status and urinary cotinine assays at the first prenatal visit for the total sample was 16.6%, significant at p < .001, chi-square = 27.80, df = 1. Based on biochemical assays of >200 ng/ml of cotinine indicating active smoking, 34.7% of women who denied smoking (specificity of 65.3%) and 10.4% of women who stated that they smoked (sensitivity of 89.5%) inaccurately reported their status (significant at p < .001). The number of cigarettes smoked per day was positively correlated with age, gravidity, parity, and number of smokers in the household. Gravidity and the number of smokers in the household were significant predictors of positive self-report of smoking status and of positive urinary cotinine assay. CONCLUSION These results substantiate the unreliability of self-report on smoking status in the pregnant population and in women who are recent quitters. Such findings have implications for clinical practice, such as (a) changes are necessary in how the prenatal interview assesses past and present tobacco use, (b) pregnant smokers who are multigravidae and who live with other smokers need more tailored interventions, and (c) more research is needed on how self-report can be ethically and efficiently validated.

Control of blood pressure and end-organ damage in maturing salt-loaded stroke-prone spontaneously hypertensive rats by oral angiotensin II receptor blockade

Objective: To study the effects of renin-angiotensin system blockade by a novel non-peptide angiotensin II receptor antagonist, losartan, on development of hypertension and acceleration of end-organ damage in salt-loaded stroke-prone spontaneously hypertensive rats (SHRSP). Design and methods: One hundred and eighty-one male SHRSP were fed a 4% sodium diet from 6 to 18 weeks of age. Seventy-eight SHRSP were treated orally with losartan, 30 mg/kg per day. One hundred and three rats constituted untreated controls. Blood pressure, plasma renin activity (PRA), renal function and end-organ damage were monitored during the transition to malignant hypertension. Results: Losartan prevented a blood pressure rise during the first 4 weeks of salt loading. Thereafter, blood pressure rose slowly in losartan-treated rats; however, at each time-point studied blood pressure was significantly lower in losartan-treated rats than in control rats. Losartan treatment increased PRA during the first 4 weeks, but this effect was not sustained. Thereafter, PRA decreased to control (week 0) levels. In contrast, 2 weeks after high-sodium feeding started, untreated SHRSP failed to suppress PRA appropriately; thereafter, PRA rose significantly. Losartan affected renal pathophysiology by blunting the decline in glomerular filtration rate, controlling proteinuria and preventing or delaying the appearance of malignant nephrosclerosis. Losartan treatment significantly increased survival and completely prevented cerebrovascular infarcts. Conclusions: The results indicate that angiotensin II blockade markedly reduces both hypertension and end-organ damage in chronically salt-loaded SHRSP and that the renin—angiotensin system may play an important role in the development of hypertensive cardiovascular disease in SHRSP.

Management of hypertension in the elderly using home blood pressures.

ObjectiveTo evaluate whether patient‐measured home blood pressures alone can be used to manage hypertension in adults 65 years and older. Methods40 hypertensive men and women, average age 73 ± 6 years, were randomly assigned to one of two treatment decision groups. The ‘home’ group (N  = 20) had blood pressure managed and medication changed according to measurements taken by the patient at home with the Omron HEM‐702 semi‐automatic oscillometric digital blood pressure monitor and the ‘clinic’ group (N  = 20) had medication adjusted based upon readings taken by the project nurse in the clinic. In both groups, treated hypertensives had medications adjusted downward, while untreated hypertensives were started on a diuretic and/or ACE inhibitor and adjustments were made upward. To assess the efficacy of the home measurements as a means of hypertension management, 24‐hour ambulatory blood pressure averages, quality of life (From the QOL SF‐36), and dosage of antihypertensive medications were compared between the home and clinic groups over a three‐month period. ResultsAt baseline, the ‘home’ group had slightly higher ambulatory awake and sleep blood pressure than the ‘clinic’ group. At 3 months, the average awake and sleep ambulatory blood pressure for the ‘home’ group decreased to the level of the ‘clinic’ group. Values of the ‘clinic’ group did not change. In both groups, pressures of previously treated patients increased over the 3 months, while those that were previously untreated declined. However, this difference, to some extent, might be expected because the acceptable limit of pressure control (150 / 90 mmHg) was higher than many of the patients on medications; thus, their pressures could increase and still be considered controlled. Those patients who were previously untreated had their pressures decreased only to this level. The nurse‐measured clinic blood pressures for the ‘home’ group began higher than that of the ‘clinic’ group and remained higher at the end of the study. Average home pressures of the ‘home’ group were consistently lower than nurse‐measured clinic pressures over the 3‐month study period, indicating a persistent ‘white coat’ effect. Both groups had similar changes in total quality of life scores. Decrease/discontinuance of antihypertensive medication was also achieved equally in both groups at the end of 3 months. ConclusionHome blood pressure monitoring alone may be as useful as clinic measurements for making treatment decisions in the elderly.

Physiological stress responses in Filipino-American immigrant nurses: the effects of residence time, life-style, and job strain.

Objective The purpose of this study was to evaluate the relationship between measures of Americanization (the adoption of American life-style and culture) and physiological measures of stress in Filipino-American immigrants. Methods Ambulatory blood pressure monitors and timed urine collections were used to evaluate blood pressure and urinary catecholamine excretion across the work, home, and sleep daily settings among 31 healthy, premenopausal, immigrant Filipino-American women employed as nurses or nurse’s aides. Migration history and life-style were evaluated from questionnaire responses. Reported job strain, decision latitude, and psychological demand were obtained from the Job Content Questionnaire. Results Immigrants who had lived longer in the United States had elevated norepinephrine levels in the work and home settings ( p < .05), higher diastolic blood pressure during sleep (p < .01), and lower dips in blood pressure during sleep (p < .05). Job strain measures were not related to blood pressure, catecholamine excretion rates, or residence time in the United States. Conclusions The results suggest that indicators of stress increase as a function of time since immigration, although this result is not explained by self-reports of identification with Filipino or American life-style or by measures of job strain.

AMBULATORY BLOOD PRESSURE MONITORING FOR EVALUATING THE RELATIONSHIPS BETWEEN LIFESTYLE, HYPERTENSION AND CARDIOVASCULAR RISK

1. Ambulatory monitoring provides a unique opportunity for studying the temporal relationships between lifestyle factors and blood pressure (BP). These include physical activity, mental activity, environmental stressors, substances ingested for pleasure such as smoking, alcohol and caffeine, and nutrition.

The association between daily blood pressure and catecholamine variability in normotensive working women.

&NA; Using ambulatory blood pressure monitors and timed urine collection techniques, blood pressure and the rates of urinary catecholamine excretion were compared across the work, home, and sleep environments of 45 women who perceived their work environment as most stressful (work stressed) and 35 women who perceived their home environment as equally or more stressful (home stressed) on the day of monitoring. The work‐stressed women had higher systolic pressure at work (121 vs. 115; p < 0.05). There were no significant differences in diastolic pressure or the absolute levels of the catecholamines between the groups. However, the percent changes in blood pressure and catecholamines from work or home to sleep were significantly correlated in the work‐stressed but not the home‐stressed women (r values from 0.25 to 0.45, p < 0.05). The work‐stressed and home‐stressed women differed in their proportional make‐up of several demographic characteristics, including having children (percentage of home‐stressed women with children > work‐stressed) (p < 0.05), ethnicity (percent of black home‐stressed > work‐stressed) (p < 0.01), and family history of hypertension (percentage of work‐stressed > home‐stressed) (0.05 < p < 0.10). These differences, in part, may have determined the daily patterns of perceived stress in the two groups of women. Overall, these findings suggest that work stress and/or the sociodemographic characteristics that may influence the perception of work stress may drive a daylong sympathetic response that increases blood pressure in working women.