Community care compared with hospital outpatient care for hypertensive patients.

Three hundred and seventy-six patients with treated diastolic blood pressures of less than 105 mm Hg and no history of accelerated hypertension or renal failure were selected from among those attending the Hammersmith Hospital hypertension clinic. Their average lying treated blood pressure was 146 mm Hg systolic and 90 mm Hg diastolic and average age 56 years; 18% were black, 6% Asian, and 76% white. The patients were mostly having multiple treatment, 90% receiving a diuretic, 35% methyldopa, 33% propranolol, 18% atenolol, 9% hydrallazine, and 7% bethanidine. They were randomly allocated to either two years of further hospital outpatient care or referred back to their general practitioners. During the two years 19 (10%) of the 187 patients followed up in hospital defaulted and three had their treatment discontinued. Twelve (6%) of the 189 followed up by their general practitioners defaulted from follow-up and nine had their treatment discontinued. At the end of the trial the average lying blood pressure was 148 mm Hg systolic and 88 mm Hg diastolic in the hospital group and 149 mm Hg systolic and 90 mm Hg diastolic in the general practice group. The change in blood pressure was calculated for each individual and showed an average fall of 1.6 mm Hg in standing diastolic pressure in the hospital group and a rise of 1.4 mm Hg in the general practice group (p less than 0.05). The 90% confidence limits for a difference in standing diastolic pressure between the groups were 1 and 5 mm Hg with the pressure lower in the hospital group. General practice care was not quite as effective in controlling blood pressure as continued specialist supervision over two years in this selected group of treated outpatients with mild or moderate hypertension, but these results show that the discharge back to general practitioners of patients who are well controlled after hospital treatment is a sensible policy.     

Current management of hypertension in general practice.

An examination of the notes of 697 patients in a random sample of seven general practices in one part of inner London showed that 164 (24%) of 669 had had a blood-pressure recording in a five-year period. Proportions varied between 4% and 36% in the different practices. The blood pressure was raised (systolic greater than or equal to 160 mm Hg or diastolic greater than or equal to 100 mm Hg or both) in 74 patients (45%) whose blood pressure had been recorded, and another recording had subsequently been made in 45 (61%) of these patients. Fifteen (21%) of those with hypertension had not had a blood-pressure recording during the five years before the study. Tranquillisers or sedatives were the commonest drugs used in the treatment of hypertension. As in a study of the management of hypertension in hospital, opportunities provided by visits to the general practitioner were not commonly used for blood-pressure screening, and the discovery of hypertension often did not lead to further action.     

Detection and management of hypertension in general practices in north west London.

An examination of the practice notes and attached correspondence of 900 patients aged 30 to 65 years in a random sample of 18 general practice in north west London showed that 340 (47%) of 716 patients consulting in a 10 year period had no blood pressure readings in their records. The blood pressure was equal to or above 160 mm Hg systolic or 95 mm Hg diastolic, or both, in 115 (31%) of those whose blood pressures were recorded; 18 (16%) of these were not followed up. Seventy four patients were being treated for hypertension. Diuretics were the most commonly prescribed drugs. Treatment was started after one blood pressure reading in 34 (46%). Nine of those who had an initial raised blood pressure reading were normotensive on follow up. A further 14 patients had subsequent raised blood pressure readings but were not treated. Sixty one (69%) of the 88 patients with hypertension did not have a blood pressure recording after diagnosis for one or more periods exceeding 12 months. Of 84 hypertensive patients with complete records, 62 (74%) apparently had had no physical examination performed by the general practitioner and 61 (72%) did not seem to have had any investigations initiated by the general practitioners. Fifteen (35%) of 43 patients taking oral contraceptive pills apparently had no blood pressure recordings during the time they were taking these. The results of this study suggest that there are still deficiencies in the detection and management of hypertension in general practice.     

Current management of hypertension in hospital.

A study of the notes of 1784 patients new to two London hospitals found a blood-pressure recording in 1027 (58%). Only 423 (32%) of all outpatients had had a blood-pressure recording on their first visit. Of 144 patients with hypertension (systolic greater than or equal to 160 mm Hg or diastolic greater than or equal 100 mm Hg or both) a check recording was made in 89 (62%) and 18 (12%) were put on treatment. We conclude that the opportunity that a hospital visit provides for blood-pressure screening is being incompletely used, and that the discovery of hypertension often does not lead to further action.     

Randomised controlled trial of computer assisted management of hypertension in primary care.

The hypothesis that general practitioners would obtain better outcomes for patients with hypertension using a computer than doctors not using a computer was tested. Sixty family physicians were randomised to two treatment strategies. "Test" physicians completed a data collection form after each visit from a patient with hypertension and mailed the forms to the test centre for processing. Computer feedback on management was mailed to the doctors. This encouraged doctors to apply the "stepped care" protocol, supplied charts of diastolic blood pressure v time, and ranked patients'' diastolic blood pressures by percentile. Letters were mailed to patients to remind them of appointments. "Control" doctors filled out the same data collection forms as test physicians, but neither doctors nor patients received computer feedback. Physicians who used the computer saw more patients per practice than control doctors (test 50 patients, control 40). For all patients the length of follow up was significantly longer in test practices (test 199 days, control 167), and a smaller percentage dropped out of active treatment in test practices (test 37.5%, control 42.1%). For patients with "moderate" hypertension of a baseline diastolic pressure of greater than 104 mm Hg the mean score of the last recorded pressure was below the goal of 90 mm Hg in test practices (88.5 mm Hg), but it failed to reach this goal in control practices (93.3 mm Hg). A greater average reduction of diastolic pressure was achieved in test practices (test 21.7 mm Hg, control 16.7 mm Hg). Though patients with "moderate" hypertension were better controlled in test practices than in control practices, the patients in test practices visited their doctors less often (test 13.3 visits per patient-year, control 17.4 visits). Among patients with newly detected hypertension test practices achieved a greater reduction in diastolic pressure than control practices (test 15.1 mm Hg v control 11.3 mm Hg) and more sustained control of hypertension (test 323 days per patient-year with a diastolic pressure of 90 mm Hg or less v control 259 days).     

Long-term follow-up of a hypertension screening program.

Of 185 people found to be hypertensive in a shopping centre screening program who went to their physician and had medication prescribed, then were contacted 18 months later, 33 had discontinued the medication at their physician''s request. But of 152 who were to continue taking medication 139 (91.4%) had complied. Blood pressure had decreased to less than 160 mm Hg systolic or less than 95 mm Hg diastolic, or both, in 65.1% of the 152; was 160 to 169 mm Hg systolic or 95 to 99 mm Hg diastolic, or both, in 13.8%; was mildly or moderately decreased but still above 169 mm Hg systolic or 99 mmHg diastolic, or both, in 8.6%; and was higher than before the onset of treatment in 3.9%. Adequacy of blood pressure control was not related to age, sex, initial blood pressure values, awareness before the screening of having hypertension, or treatment for hypertension before the screening. Diuretics had been prescribed for 93.5% of the 139 patients, most often as single-pill combinations with other antihypertensive agents.     

Screening for hypertension in a high school population.

Of 15 594 high school students (ages, 15 to 20) whose blood pressure was measured in a screening program, 350 (2.2%) has hypertensive readings (150 mm Hg or more systolic, or 95 mm Hg or more diastolic, or both). The mean blood pressure for the boys was 125.0 plus or minus 12.1/71.8 plus or minus 10.9 mm Hg, and for the girls, 119.8 plus or minus 10.2/72.3 plus or minus 9.2 mm Hg. The parents of the students with hypertensive readings were advised to send their children to a physician. By 6 months, of the 232 who were followed up, 156 (67.2%) has visited a physician and in 19 cases (12.2%) the physician had confirmed the hypertensive readings. Only one student, an asymptomatic 17-year-old boy whose hypertension had not previously been detected, was found to have secondary hypertension, which was relieved surgically. Of the 18 hypertensive students 4 are currently receiving antihypertensive medication and 8 continue to have their blood pressure monitored. The mean blood pressures recorded in the physicians'' offices averaged 23.7/11.1 mm Hg less than those recorded in the schools. One reason for this was that none of the physicians used pediatric cuffs, but these were required by 62.4% of the students at the screening. Hence, the intravascular blood pressure was probably underestimated in a number of cases in the physicians'' offices.     

Controlled trial of biofeedback-aided behavioural methods in reducing mild hypertension.

Employees of a large industry were screened for the presence of coronary risk factors. A total of 204 employees, aged 35-64 years, with two or more such factors (serum cholesterol concentration greater than or equal to 6.3 mmol/l (243.6 mg/100 ml), blood pressure greater than or equal to 140/90 mm Hg, and current cigarette consumption greater than or equal to 10 cigarettes a day) were randomly allocated to a biofeedback group receiving training in relaxation and management of stress or a control group. Both groups received simple health education literature. After eight weeks of training, and again eight months later, the biofeedback group showed a significantly greater fall in systolic and diastolic blood pressures than the control group (p less than 0.001). Plasma renin activity and plasma aldosterone concentration were measured in a subsample at entry to the study and again at eight weeks and eight months; both showed a greater reduction in the biofeedback compared with the control group at eight weeks'' follow-up. The greater reduction in blood pressure in the subjects in the biofeedback group compared with the control group (11.0 mm Hg systolic and 8.8 mm Hg diastolic), persisting eight months after the training, suggests that relaxation-based behavioural methods might be offered as a first-time treatment to patients with mild hypertension.     

Approach to drug therapy for hypertension.

Prevention of complications of hypertension requires the lowering of blood pressure. The therapeutic goal is to achieve and maintain a diastolic pressure of less than 90 mm Hg with minimal adverse effects. The treatment of patients with established diastolic blood pressures between 90 and 104 mm Hg (determined from three separate readings) should be individualized; general measures such as weight loss and salt restriction should be tried first as an alternative to drug therapy. Patients with diastolic pressure in excess of 104 mm Hg should be treated with antihypertensive drugs; the first step should be the use of a thiazide diuretic in addition to general measures. Patients with diastolic pressures of 90 to 115 mm Hg may require the addition of a beta-adrenergic-receptor antagonist, methyldopa or clonidine if the therapeutic goal is not achieved; rarely they require the further addition of hydralazine or prazosin. Patients with diastolic pressures of 116 to 129 mm Hg usually require initially both a thiazide diuretic and a beta-blocker, methyldopa or clonidine; if the therapeutic goal is not achieved, hydralazine or prazosin is added, and if a further hypotensive effect is required guanethidine can be added. Patients with severe hypertension (diastolic pressures greater than 130 mm Hg) may require urgent treatment with combinations of drugs of all three levels. Emphasis should be placed on individualized therapy and patient compliance in the assessment of therapeutic failures. These "step-care" guidlines represent a framework for antihypertensive therapy devised from information available in 1977. It is not a rigid scheme and should be adjusted to the individual patient to ensure as normal a life as possible.     

Fetal and placental size and risk of hypertension in adult life.

OBJECTIVE--To study the effect of intrauterine growth and maternal physique on blood pressure in adult life. DESIGN--A follow up study of infants born 50 years previously whose measurements at birth were recorded in detail. SETTING--Preston, Lancashire. SUBJECTS--449 Men and women born in hospital in Preston during 1935-43 and still living in Lancashire. MAIN OUTCOME MEASURES--Placental weight, birth weight, and blood pressure at age 46 to 54 years. RESULTS--In both sexes systolic and diastolic pressures were strongly related to placental weight and birth weight. Mean systolic pressure rose by 15 mm Hg as placental weight increased from less than or equal to 1 lb (0.45 kg) to greater than 1.5 lb and fell by 11 mm Hg as birth weight increased from less than or equal to 5.5 lb to greater than 7.5 lb. These relations were independent so that the highest blood pressures occurred in people who had been small babies with large placentas. Higher body mass index and alcohol consumption were also associated with higher blood pressure, but the relations of placental weight and birth weight to blood pressure and hypertension were independent of these influences. CONCLUSIONS--These findings show for the first time that the intrauterine environment has an important effect on blood pressure and hypertension in adults. The highest blood pressures occurred in men and women who had been small babies with large placentas. Such discordance between placental and fetal size may lead to circulatory adaptation in the fetus, altered arterial structure in the child, and hypertension in the adult. Prevention of hypertension may depend on improving the nutrition and health of mothers.     

Case-control study of stroke and the quality of hypertension control in north west England.

OBJECTIVE: To examine the risk of stroke in relation to quality of hypertension control in routine general practice across an entire health district. DESIGN: Population based matched case-control study. SETTING: East Lancashire Health District with a participating population of 388,821 aged < or = 80. SUBJECTS: Cases were patients under 80 with their first stroke identified from a population based stroke register between 1 July 1994 and 30 June 1995. For each case two controls matched with the case for age and sex were selected from the same practice register. Hypertension was defined as systolic blood pressure > or = 160 mm Hg or diastolic blood pressure > or = 95 mm Hg, or both, on at least two occasions within any three month period or any history of treatment with antihypertensive drugs. MAIN OUTCOME MEASURES: Prevalence of hypertension and quality of control of hypertension assessed by using the mean blood pressure recorded before stroke) and odds ratios of stroke (derived from conditional logistic regression). RESULTS: Records of 267 cases and 534 controls were examined; 61% and 42% of these subjects respectively were hypertensive. Compared with non-hypertensive subjects hypertensive patients receiving treatment whose average pre-event systolic blood pressure was controlled to < 140 mm Hg had an adjusted odds ratio for stroke of 1.3 (95% confidence interval 0.6 to 2.7). Those fairly well controlled (140-149 mm Hg), moderately controlled (150-159 mm Hg), or poorly controlled (> or = 160 mm Hg) or untreated had progressively raised odds ratios of 1.6, 2.2, 3.2, and 3.5 respectively. Results for diastolic pressure were similar; both were independent of initial pressures before treatment. Around 21% of strokes were thus attributable to inadequate control with treatment, or 46 first events yearly per 100,000 population aged 40-79. CONCLUSIONS: Risk of stroke was clearly related to quality of control of blood pressure with treatment. In routine practice consistent control of blood pressure to below 150/90 mm Hg seems to be required for optimal stroke prevention.     

Angiotensin II in essential hypertension.

Plasma concentrations of angiotensin II (PAC) were measured in a group of 146 hypertensive patients (diastolic pressure greater than 105 mm Hg) who had no apparent underlying cause for their condition and 113 randomly selected normotensive controls (diastolic pressure less than 90 mm Hg). There was no evidence of bimodality in the frequency distribution curves for plasma angiotensin II concentrations among the hypertensive patients. It was concluded that hypertension associated with low angiotensin II concentration and by implication "low-renin" hypertension is not a condition separate from essential hypertension.     

Sodium restriction and blood pressure in hypertensive type II diabetics: randomised blind controlled and crossover studies of moderate sodium restriction and sodium supplementation.

OBJECTIVE--To determine the effect of moderate dietary sodium restriction on the hypertension of non-insulin-dependent (type II) diabetes. DESIGN--Randomised parallel controlled study of moderate sodium restriction for three months compared with usual diabetic diet, followed by randomised double blind crossover trial of sustained release preparation of sodium for one month versus placebo for one month in patients continuing with sodium restriction. SETTING--Patients attending diabetic outpatient clinic of city hospital. PATIENTS--Thirty four patients with established type II diabetes complicated by mild hypertension (systolic blood pressure greater than 160 mm Hg or diastolic pressure greater than 95 mm Hg on three consecutive occasions). Patients already taking antihypertensive agents (but not diuretics) not barred from study provided that criteria for mild hypertension still met. Conditions precluding patients from study were diabetic or hypertensive nephropathy, cardiac failure, and pregnancy. INTERVENTIONS--After run in phase with recordings at seven weeks, three weeks, and time zero patients were allocated at random to receive moderate dietary sodium restriction for three months (n = 17) or to continue with usual diabetic diet. Subsequently nine patients in sodium restriction group continued with regimen for a further two months, during which they completed a randomised double blind crossover trial of sustained release preparation of sodium (Slow Sodium 80 mmol daily) for one month versus matching placebo for one month. END POINT--Reduction in blood pressure in type II diabetics with mild hypertension. MEASUREMENTS AND MAIN RESULTS--Supine and erect blood pressure, body weight, and 24 hour urinary sodium and potassium excretion measured monthly during parallel group and double blind crossover studies. After parallel group study sodium restriction group showed significant reduction in systolic blood pressure (supine 19.2 mm Hg, erect 21.4 mm Hg; p less than 0.001) and mean daily urinary sodium excretion (mean reduction 60 mmol/24 h). There were no appreciable changes in weight, diabetic control, or diastolic pressure. No significant changes occurred in controls. In double blind crossover study mean supine systolic blood pressure rose significantly (p less than 0.005) during sodium supplementation (to 171 mm Hg) compared with value after three months of sodium restriction alone (159.9 mm Hg) and after one month of placebo (161.8 mm Hg). CONCLUSIONS--Moderate dietary restriction of sodium has a definite hypotensive effect, which may be useful in mild hypertension of type II diabetes.     

Lack of additional action of oxygen on pulmonary artery pressure at the peak of verapamil or captopril action in pulmonary hypertension secondary to mitral stenosis]

The aim of the study was to investigate whether oxygen causes a further decrease in pulmonary artery pressure after administration of calcium channel blocker-verapamil-or angiotensin converting enzyme inhibitor-captopril-in the secondary pulmonary hypertension. We studied 37 patients with the secondary pulmonary hypertension (mean pulmonary artery systolic pressure = 56.1 mm Hg) due to mitral stenosis. After having completed hemodynamic diagnostic procedures, basal oxygen test was performed and pulmonary artery pressure was recorded at 10 min of oxygen breathing. Then, 10 mg of verapamil was injected into the pulmonary artery of 16 patients and 21 patients received 75 mg of oral captopril. At the peak of vasodilation, 30 min after verapamil and 90 min after captopril administration, pulmonary artery pressure was recorded and oxygen test was repeated. Baseline oxygen test produced a statistically significant decrease in pulmonary artery pressure. Verapamil and captopril also lowered pulmonary artery systolic and diastolic pressures. The second oxygen test did not cause a further decrease in the pulmonary artery pressure; mean pulmonary artery systolic pressure was 52.3 +/- 23.7 mm Hg, pulmonary artery diastolic pressure 22.7 +/- 10.6 mm Hg before and 49.1 +/- 23.8 mm Hg and 23.0 +/- 13.5 mm Hg, respectively after the test in verapamil group, and 47.0 +/- 15.5 mm Hg and 21.7 +/- 8.4 mm Hg before and 46.6 +/- 15.4 mm Hg, respectively in captopril subset. The results may support the thesis that vasodilating effect depends rather on the degree of pulmonary vascular changes than on the vasodilatory mechanism of particular drugs.     

A controlled study of eight months of physical training and reduction of blood pressure in children: the Odense schoolchild study.

OBJECTIVE--To examine the effect of physical training on physical fitness and blood pressure in children aged 9-11 years. DESIGN--Prospective randomised controlled intervention study of a sample of children drawn from a population survey of coronary risk factors in children. SETTING--Odense, Denmark. SUBJECTS--69 children with mean blood pressure greater than or equal to 95th centile (hypertensive group) and 68 with mean blood pressure less than 95th centile (normotensive group), randomly selected from a population of 1369 children. INTERVENTION--67 children were randomised to receive three extra lessons a week of an ordinary school physical education programme for eight months. MAIN OUTCOME MEASURES--Physical fitness assessed by calculation of maximum oxygen uptake and blood pressure recorded by one unblinded observer. RESULTS--After three months neither blood pressure nor physical fitness had changed significantly. After adjustment for values in weight, height, heart rate, and the variable in question before training physical fitness rose significantly at the end of eight months'' training, by 3.7 mlO2/kg/min (95% confidence interval 2.2 to 5.3) in the normotensive training subgroup and by 2.1 mlO2/kg/min (0.1 to 4.2) in the hypertensive training subgroup compared with that in the controls. Systolic and diastolic blood pressures in the training subgroups fell significantly by 6.5 mm Hg (3.2 to 9.9) and 4.1 mm Hg (1.7 to 6.6) respectively in the normotensive group and by 4.9 mm Hg (0.7 to 9.2) and 3.8 mm Hg (0.9 to 6.6) respectively in the hypertensive group. CONCLUSIONS--Physical training lowers blood pressure and improves physical fitness in children and might have implications for an important non-pharmacological approach to primary prevention of essential hypertension.     

Blood Pressure in a Scottish Town

As part of a general health screening survey in the Burgh of Renfrew blood pressure was measured in 3,001 subjects (78·8% of those eligible) aged 45 to 64. In 468 (15·6%) diastolic blood pressure was 100 mm Hg or more. A year later the mean blood pressure for those of the population re-examined showed no change, there being an equal number of subjects with increased and decreased pressures. The prognostic significance of those showing the larger fluctuations remains to be determined through medical-record linkage.Examination of the general practitioners'' medical records of 422 of the 468 subjects with diastolic blood pressure of 100 mm Hg or more showed that 255 had no previous documented hypertension. Of the remainder 73 were receiving antihypertensive therapy. Examination of the records of subjects whose blood pressure was under 100 mm Hg showed that 55 were receiving antihypertensive treatment and that another 113 had previously been recorded as having a diastolic blood pressure of 100 mm Hg or more by their general practitioner. Altogether at least 636 (21·2%) of those who were examined had been considered at some time to have evidence of hypertension.The prevalence of undetected hypertension in the general population has important implications for the resources of the National Health Service if current trials show benefit to the health of the community from treating “mild” as well as “moderate” hypertension.     

General practitioners' management of hypertension in elderly patients.

OBJECTIVE--To assess general practitioners'' attitudes to the diagnosis and management of hypertension in elderly patients. DESIGN--Postal questionnaire to all general practitioners in Leicestershire. RESULTS--360 of 451 general practitioners (80%) responded. 81% (292) reported rechecking an initially high blood pressure on two or three occasions before starting treatment, 56% (202) measured sitting blood pressure only, and just 28% (100) took sitting and standing levels. 36% (128) had no upper age limit for starting anti-hypertensive treatment; of the 58% (206) who did, the median was 80 (range 70-99) years. Blood pressure levels reported for starting treatment in patients aged 70-79 years were 180 (150-240)/106 (90-120) mm Hg. 34% of general practitioners (121) would not treat isolated systolic hypertension. The most popular first line treatment for an elderly hypertensive patient was a thiazide diuretic; only 17% of general practitioners (61) initially tried non-pharmacological methods. 34% (122) would continue anti-hypertensive treatment unchanged in the period immediately after stroke. CONCLUSIONS--The variation among general practitioners in the criteria for the measurement, diagnosis, and treatment of hypertension in elderly patients emphasises the need for clear management guidelines in this age group.     

Three year follow up of patients with raised blood pressure identified at health checks in general practice.

OBJECTIVE--To assess the extent of three year follow up of blood pressure, weight, and smoking habit in patients with raised blood pressure identified at health checks. DESIGN--Retrospective audit of medical and nursing records. SETTING--Three general practices in Oxfordshire. PATIENTS--386 of 448 patients with raised blood pressure (diastolic greater than or equal to 90 or systolic greater than or equal to 160 mm Hg) identified from 2935 patients aged 35-64 attending health checks in 1982-4. MEASUREMENTS and MAIN RESULTS--All records of blood pressure, weight, and smoking habit in the medical record were abstracted for three years after the initial health check. All 42 patients with an initial diastolic blood pressure greater than or equal to 105 mm Hg and 316 of 344 patients with an initial pressure of 90-104 mm Hg had at least one further measurement of their blood pressure. Follow up of smoking habit and of weight was less complete with only half of the 100 smokers and 67 of the 87 obese patients (body mass index greater than or equal to 30) having any documented follow up of these risk factors. Annual follow up in the second and third years occurred in 228/297 (76.8%) and 232/320 (72.5%) in patients with blood pressure greater than 95 mm Hg at the beginning of each year. For patients who smoked annual follow up in these years occurred in fewer than a third and for those who were obese in just over half. On the assumption that those not followed up had not changed, at the end of three years the proportion of patients with diastolic blood pressure greater than or equal to 100 mm Hg had fallen from 61 patients (15.8%) to 31 (8.1%); the proportion of smokers had fallen from 103 (26.7%) to 94 (24.4%); and the proportion of obese patients had fallen from 87 (22.5%) to 79 (20.5%). CONCLUSIONS--These changes were modest and in the absence of a control group cannot be attributed necessarily to health checks. Although the standard of follow up was better than in previously reported studies of the management of hypertension, the results emphasise the need to develop formal protocols for dietary and antismoking interventions and to evaluate formally the effectiveness (and cost effectiveness) of health checks.     

The dilemma of isolated systolic hypertension.

Isolated systolic hypertension, characterized by elevated systolic blood pressure (greater than 150 to 165 mm Hg), normal diastolic blood pressure (less than 90 to 95 mm Hg) and, often, atherosclerosis, is now recognized as an important risk factor for cardiovascular disease. When the systolic pressure is 200 mm Hg or greater, or when it is 180 mm Hg or greater and accompanied by target organ damage, therapeutic intervention may be of value in patients under the age of 80 years. Low doses of thiazide diuretics have been shown to be safe and effective in lowering the systolic pressure. If the blood pressure remains high, treatment with methyldopa may be added.     

Effect of environment on blood pressure: home versus hospital.

The effect of environment on blood pressure was studied by recording intra-arterial pressure continuously in nine patients with essential hypertension during controlled periods of activity and rest at home and in hospital. Mean systolic pressure was higher at home (152 +/- 16 mm Hg) than in hospital (138 +/- 11 mm Hg, p less than 0.01), the difference being greatest during the period of activity (165 +/- 21 v 142 +/- 13 mm Hg, p less than 0.001); heart rates and diastolic pressures did not differ significantly at these times. Systolic pressure recorded by conventional sphygmomanometry was also higher at home (173 +/- 23 v 159 +/- 23 mm Hg, p less than 0.01), as was diastolic pressure (98 +/- 10 v 89 +/- 11 mm Hg, p less than 0.02). Systolic pressure was consistently higher at home, and this effect was independent of the pressure of an observer. This must be taken into consideration when assessing blood pressure and efficacy of treatment in hospital.