Hemodynamic characteristics of the early phase of primary hypertension. The Dutch Hypertension and Offspring Study.

BACKGROUND: The hemodynamic characteristics of the early phase of primary hypertension are subject to debate. In particular, it remains unclear whether an increased vascular peripheral resistance or a raised cardiac output is involved as the primary hemodynamic alteration in hypertension. METHODS AND RESULTS: We studied hemodynamic characteristics and oxygen consumption in relation to 24-hour ambulatory blood pressure measurements in three groups of normotensive children with a different familial predisposition for hypertension. Selection of participants was based on parental blood pressure levels. Mean 24-hour blood pressure was higher in the offspring of two hypertensive parents compared with the offspring of two normotensive parents; there was a difference of 4.7 mm Hg (95% confidence interval [CI], 1.8-7.6) for systolic blood pressure and a difference of 4.8 mm Hg (CI, 2.3-7.3) for diastolic blood pressure. The 24-hour blood pressure pattern was consistently at a higher level for both systolic and diastolic blood pressures in the offspring of two hypertensive parents compared with the offspring of two normotensive parents. The smallest differences in blood pressure were seen at night, and the largest differences in blood pressure between the groups of offspring were seen during periods of physical activity. Echocardiographic examination combined with registration of oxygen consumption did not show a difference in cardiac index and arteriovenous oxygen difference between the study groups. However, differences in cardiac dimensions were apparent, with an increased left ventricular mass index (8.7 g/m2; CI, 2.4-15.0) in the offspring of two hypertensive parents. CONCLUSIONS: These findings do not support the existence of a hyperkinetic circulatory phase but may indicate the presence of an increased left ventricular mass in early primary hypertension.

A questionnaire survey of symptoms in a hypertension clinic.

OBJECTIVE: to assess symptoms of patients on antihypertensive therapy. SETTING: hospital hypertension clinic. DESIGN: self administered questionnaire (sent and returned by mail) listing 23 symptoms; four grades of response (none, mild or seldom, moderate or sometimes, severe or frequent); special scale for nocturia and appetite. PATIENTS: 302 patients completed the questionnaire (87% of those to whom it was sent); 109 of these patients completed it a second time, after an interval of four months, so that repeatability could be assessed. REPEATABILITY: scores were high, ranging from 0.92 to 0.99, for all symptoms except flushing (all grades 0.91), nausea (all grades 0.90) and sleepiness (severe, 0.82) (method of Bulpitt et al). RESULTS: overall prevalence of symptoms was high, but most were mild or infrequent. Women had significantly greater prevalence of oedema, flushing and insomnia than men and tended to assess their symptoms more often as severe or frequent. Nocturia was the only symptom more common in those above median age (62 yr) than in those below. Lack of energy was the only symptom more prevalent in the treated than in the untreated. No difference in prevalence of symptoms was detected between those taking or not taking a specific type of drug (beta blocker, diuretic, ACE inhibitor, calcium antagonist). CONCLUSION: in patients whose antihypertensive therapy has been carefully adjusted to try to avoid symptomatic side effects, the burden of such side effects appears to be very small.

Changes in clinical characteristics and drug treatment of hypertension over 40 years at the Dunedin Hypertension Clinic.

The clinical characteristics of the 4,170 hypertensive patients referred to the Dunedin Clinic from 1950 to 1989 have been compared for eight successive 5-year periods. A gradual decrease in the severity of referred hypertension and an increase in the proportion of patients already on treatment at the time of referral (currently 50%) were noted. For male patients, mean +/- SD initial lying blood pressure was 179 +/- 27/116 +/- 19 mm Hg in 1950-1954 and 158 +/- 25/91 +/- 14 mm Hg in 1985-1989. Corresponding prevalence data for target organ damage among male patients were retinal grade 3 or 4, 49% and 3%; cardiomegaly on chest radiograph, 60% and 26%; electrocardiogram left ventricle strain pattern, 28% and 3%; and serum urea levels greater than 10 mmol/L, 16% and 5%, respectively. For women there was a similar trend. The number of patients on drugs in each of nine categories and the percent use of each drug category for each year during 1950-1989 was recovered from computerized data files. The percentage peak usage of ganglion blockers was in 1950-1958, adrenergic neuron blockers in 1963-1970, centrally acting drugs in 1965-1968, diuretics in 1960-1982, beta-blockers in 1974-1987, alpha-blockers in 1980-1987, and angiotensin converting enzyme inhibitors and calcium antagonists in 1989. The diuretics have been the most enduring drugs, followed by the beta-blockers.

Risk predictors in treated hypertension.

The data for patients referred to the Dunedin Hypertension Clinic (975 men, 1,348 women) between 1953 and 1977 have been examined by the Cox proportional hazards method for significant age-corrected predictors of 8-year cardiovascular and total mortality. For men, some significant predictors were systolic and diastolic blood pressure (BP), indices of target organ damage (heart and eyes) and smoking at presentation, and achieved BP and serum cholesterol at follow-up. For women, serum cholesterol, diabetes, target organ damage (heart and eyes) and smoking at presentation, and achieved BP level at follow-up were predictors. Relative risk for total or cardiovascular mortality was increased in both sexes most by smoking and by increased levels of achieved BP.

Twenty-four-hour ambulatory blood pressure pattern in youngsters with a different family history of hypertension: the Dutch Hypertension and Offspring Study.

The offspring of hypertensive parents in general show higher casual blood pressure levels during adolescence than the offspring of normotensive parents. Comparative ambulatory blood pressure measurements might reveal the stability and pattern of this difference during circadian blood pressure variation. We studied the 24-h ambulatory blood pressure (Space-Labs 90202 monitor, Redmond, Washington, USA) in youngsters with two hypertensive parents (high; n = 62), with one hypertensive parent (mixed; n = 51) and with no hypertensive parent (low; n = 42). The pattern for both systolic and diastolic blood pressure in the three groups ran parallel, with the high group continuously at a higher level. A clear difference in systolic blood pressure was observed during the day period (high minus low: 5.4 mmHg; 95% confidence range 2.5-8.3). Our data show that offspring of hypertensive parents differ in ambulatory blood pressure levels, but not in the circadian pattern, from the offspring of normotensive parents.

Eight-year survival study of treated hypertension at the Dunedin Hypertension Clinic 1953-1977.

The 8-year follow-up data of consecutive 5-year cohorts of hypertensive patients starting treatment at the Dunedin Hypertension Clinic between 1953 and 1977 have been analysed. There were 975 men and 1348 women. Since 1953 treatment has been initiated in progressively milder forms of hypertension, and blood pressure has been controlled at progressively lower levels. The mean age at presentation for both men and women was 51 years. The mean age at death and the cause of death did not differ significantly among the cohorts, but the percentage incidence of events (including death) over the 8-year follow-up decreased significantly (P less than 0.0001) from 76% for males and 57% for females in the 1953-1957 cohort, to 33% for males and 25% for females in the 1973-1977 cohort. Survival was poorest in the earlier cohorts, especially the 1953-1957 cohort. The 8-year relative survival of treated hypertensives compared with the general population of New Zealand improved over time and was about 0.9 for the 1973-1977 cohort, a little less for males and a little more for females.

The Spielberger Anger Expression Scale: some psychometric data.

Some general population norms for the Spielberger, Johnson et al. (1984) Anger Expression Scale (AX) are reported for a sample of over 1000 adults tested in a general health survey of a New Zealand community. Factor analysis confirmed the independence of the Anger/In and Anger/Out subscales, and the measure was found to have satisfactory levels of reliability.

Effects of arm position and support on blood-pressure readings.

The effect of changes in arm position and of arm support on blood-pressure readings was assessed in 240 hypertensive outpatients with the arm in various positions. Mean blood pressure was lowest with the arm supported at heart height and highest with the arm dependent, the difference averaging 8 mmHg for both systolic and diastolic pressure and being greater for men than for women. Arm support at heart height lowered blood pressure only slightly, when compared to that taken on the unsupported arm at heart height. These findings suggest that an increase in apparent blood pressure associated with arm dependency during the recording can spuriously increase the height of the blood pressure and the prevalence of hypertension. In the individual patient it may lead to unnecessary increase in antihypertensive dosage. Whenever standing blood pressure is quoted, arm position should be stated.

Self-reported anger intensity and blood pressure.

During a health survey of a New Zealand community, two S-R inventories measuring responsiveness to anger and to anxiety provoking situations were administered to 1127 adults. With age treated as a covariate, no association was found between scores on these measures and blood pressure.

The relationship between blood pressure and personality in a large unselected adult sample.

As part of a general health survey of a small New Zealand town, the Crow-Crisp Experiential Index, the State-Trait Anxiety Inventory, a shortened version of the Hostility and Direction of Hostility Questionnaire, and the Zung Self-rating Depression Scale were administered to 1173 subjects over the age of 15. Blood pressure was moderately correlated with age and Quetelet's Index, a measure of obesity. Low but significant correlations were found between Somatic Anxiety, Hysteria, and the Urge to Act-out Hostility scale. However, when effects of age were controlled for, in a series of multiple regression analyses, the correlations with psychometric test scores were no longer significant. This study confirms several previous reports that neuroticism, anxiety, depression, and hostility are of little significant in predicting levels of blood pressure in the general population.

Alcohol consumption and blood pressure in a New Zealand community study.

The relationship between stated alcohol consumption and blood pressure was investigated in 901 adults who participated in a multiphasic health survey in Milton in May 1981. Subjects taking oral contraceptives or drugs which could lower blood pressure were excluded. Eighty-five percent of men and 52% of women reported taking some alcohol at least once a month. The percentage using alcohol was highest (96%) in men aged 20-29 years. The reported mean weekly intake by users was 171 g for men and 56 g for women. After adjustment for age and body mass index, there was a positive association between alcohol intake and blood pressure for men. The mean systolic and diastolic pressures of male heavy alcohol users (300 g or more alcohol per week) were, respectively, 9.8 and 8.9 mmHg higher than those of male non-drinkers. No relationship between alcohol intake and blood pressure was found in the women.