Systolic and diastolic blood pressures as predictors of coronary heart disease mortality in the Whitehall study.

Systolic and diastolic blood pressures were compared as predictors of death due to coronary heart disease using data on the 10 year mortality outcome from the 18 403 male civil servants, aged 40-64, in the Whitehall study. There were 727 deaths due to coronary heart disease. At entry to the study the systolic pressure in these men was significantly higher than the diastolic pressure, and a standardised index of relative risk for death from coronary heart disease was greater for systolic blood pressure. After adjustment for age the top quintile of systolic pressure (greater than 151 mm Hg) identified 5% more men at risk of death from coronary heart disease than for the top diastolic quintile (greater than 95 mm Hg). The findings suggested that clinicians should pay more attention to systolic levels as a criterion for making diagnostic and therapeutic decisions.     

Systematic review of randomised controlled trials of multiple risk factor interventions for preventing coronary heart disease.

OBJECTIVE: To assess the effectiveness of multiple risk factor intervention in reducing cardiovascular risk factors, total mortality, and mortality from coronary heart disease among adults. DESIGN: Systematic review and meta-analysis of randomised controlled trials in workforces and in primary care in which subjects were randomly allocated to more than one of six interventions (stopping smoking, exercise, dietary advice, weight control, antihypertensive drugs, and cholesterol lowering drugs) and followed up for at least six months. SUBJECTS: Adults aged 17-73 years, 903000 person years of observation were included in nine trials with clinical event outcomes and 303000 person years in five trials with risk factor outcomes alone. MAIN OUTCOME MEASURES: Changes in systolic and diastolic blood pressure, smoking rates, blood cholesterol concentrations, total mortality, and mortality from coronary heart disease. RESULTS: Net decreases in systolic and diastolic blood pressure, smoking prevalence, and blood cholesterol were 4.2 mm Hg (SE 0.19 mm Hg), 2.7 mm Hg (0.09 mm Hg), 4.2% (0.3%), and 0.14 mmol/l (0.01 mmol/l) respectively. In the nine trials with clinical event end points the pooled odds ratios for total and coronary heart disease mortality were 0.97 (95% confidence interval 0.92 to 1.02) and 0.96 (0.88 to 1.04) respectively. Statistical heterogeneity between the studies with respect to changes in mortality and risk factors was due to trials focusing on hypertensive participants and those using considerable amounts of drug treatment, with only these trials showing significant reductions in mortality. CONCLUSIONS: The pooled effects of multiple risk factor intervention on mortality were insignificant and a small, but potentially important, benefit of treatment (about a 10% reduction in mortality) may have been missed. Changes in risk factors were modest, were related to the amount of pharmacological treatment used, and in some cases may have been overestimated because of regression to the mean, lack of intention to treat analyses, habituation to blood pressure measurement, and use of self reports of smoking. Interventions using personal or family counselling and education with or without pharmacological treatments seem to be more effective at reducing risk factors and therefore mortality in high risk hypertensive populations. The evidence suggests that such interventions implemented through standard health education methods have limited use in the general population. Health protection through fiscal and legislative measure may be more effective.     

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.     

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.     

Factors predictive of attendance at clinic and blood pressure control in hypertensive patients.

Poor compliance with appointments and drug treatment is one of the recognised factors preventing effective management of hypertension. Factors predictive of poor attendance and inadequate blood pressure control in patients attending a hypertension clinic were therefore determined using univariate analyses and a multivariate logistic model. Out of 1346 patients with blood pressure exceeding 160/95 mm Hg followed up for three years, 209 (15.5%) dropped out during the first year. Variables that were significantly related to increased drop out rates were male sex, young age, obesity at entry, cigarette smoking, direct referral to the clinic as a result of screening instead of referral by a general practitioner, absence of pre-existing antihypertensive treatment at the first visit, moderate hypertension, and low socioeconomic category. Variables at entry that were significantly related to poor blood pressure control at one year were old age, evidence of coronary heart disease, severe hypertension, and raised blood glucose concentrations. Early detection of patients at high risk of drop out or poor blood pressure control might improve treatment of hypertension and allow management to be more individually adapted to each patient.     

Control of blood pressure in Scotland: the rule of halves.

OBJECTIVE--Audit of detection, treatment, and control of hypertension in adults in Scotland. DESIGN--Cross sectional survey with random population sampling. SETTING--General practice centres in 22 Scottish districts. SUBJECTS--5123 Men and 5236 women aged 40-59 in the Scottish heart health study, randomly selected from 22 districts throughout Scotland, of whom 1262 men and 1061 women had hypertension (defined as receiving antihypertensive treatment or with blood pressure above defined cut off points). MAIN OUTCOME MEASURE--Hypertension (assessed by standardised recording, questionnaire on diagnosis, and antihypertensive drug treatment) according to criteria of the World Health Organisation (receiving antihypertensive treatment or blood pressure greater than or equal to 160/95 mm Hg, or both) and to modified criteria of the British Hypertension Society. RESULTS--In half the men with blood pressure greater than or equal to 160/95 mm Hg hypertension was undetected (670/1262, 53%), in half of those in whom it had been detected it was untreated (250/592, 42%), and in half of those receiving treatment it was not controlled (172/342, 50%). In women the numbers were: 486/1061, 46%; 188/575, 33%; and 155/387, 40% respectively. Assessment of blood pressure according to the British Hypertension Society''s recommendations showed an improvement, but in only a quarter of men and 42% of women was hypertension detected and treated satisfactorily (142/561, 215/514 respectively). IMPLICATIONS--The detection and control of hypertension in Scotland is unsatisfactory, affecting management of this and other conditions, such as high blood cholesterol concentration, whose measurement is opportunistic and selective and depends on recognition of other risk factors.     

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.     

Risk factors for stroke in middle aged British men.

OBJECTIVE--To determine the risk factors for stroke in a cohort representative of middle aged British men. DESIGN--Prospective study of a cohort of men followed up for eight years. SETTING--General practices in 24 towns in England, Wales, and Scotland (the British regional heart study). SUBJECTS--7735 men aged 40-59 at screening, selected at random from one general practice in each town. MAIN OUTCOME MEASURE--Fatal and non-fatal strokes. RESULTS--110 of the men had at least one stroke; there were four times as many non-fatal as fatal strokes. The relative risk of stroke was 12.1 in men who had high blood pressure (systolic blood pressure greater than or equal to 160 mm Hg) and were current smokers compared with normotensive, non-smoking men. Diastolic blood pressure yielded no additional information, and former cigarette smokers had the same risk as men who had never smoked. Heavy alcohol intake was associated with a relative risk of stroke of 3.8 in men without previously diagnosed cardiovascular disease. Men with pre-existing ischaemic heart disease had an increased risk of stroke, but only when left ventricular hypertrophy on electrocardiography was also present. CONCLUSIONS--Systolic blood pressure, cigarette smoking, and left ventricular hypertrophy on electrocardiography in men with pre-existing ischaemic heart disease were found to be the major risk factors for stroke in middle aged British men. Heavy alcohol intake seemed to increase the risk of stroke in men without previously diagnosed cardiovascular disease. A large proportion of strokes should be preventable by controlling blood pressure and stopping smoking.     

Cardiovascular effects of training for a marathon run in unfit middle aged men.

The effects of a 30 week exercise programme on serum lipid values, blood pressure, and cardiac function were assessed in a group of sedentary men aged 35-50 training for their first marathon. Mean serum cholesterol concentration (n = 33) fell by 12% from 6.54 (SE 0.18) to 5.76 (0.15) mmol/l (mean fall 0.78 mmol/l; 95% confidence interval 0.52 to 1.04 mmol/l), serum triglyceride concentration (n = 33) by 22% from 1.56 (0.17) to 1.21 (0.09) mmol/l (mean fall 0.34 mmol/l; 95% confidence interval 0.12 to 0.56 mmol/l), and mean blood pressure (n = 27) by 10% from 102 (2) to 92 (2) mm Hg (mean fall 10 mm Hg; 95% confidence interval 7 to 13 mm Hg). These changes were not explained by changes in body composition. Peak exercise left ventricular end diastolic volume (n = 16) increased with training; as a result of this and an increased exercise left ventricular ejection fraction peak exercise cardiac output increased from 19.9 (1.2) to 23.1 (3.0) l/min (mean rise 3.2 l/min; 95% confidence interval 1.5 to 5.0 l/min). Maximum oxygen consumption increased from 33.9 (1.6) to 39.0 (1.3) ml/kg/min (mean rise 5.0 ml/kg/min; 95% confidence interval 1.8 to 8.2 ml/kg/min). This study showed favourable effects on coronary risk factors and cardiac function and supports the place of regular exercise in coronary prevention programmes.     

Plasma cholesterol concentration and death from coronary heart disease: 10 year results of the Whitehall study.

Ten year mortality from coronary heart disease in 17,718 middle aged men was related to their initial plasma cholesterol concentrations. The relative risk of death from coronary heart disease declined with age, but the absolute excess risk did not. The risk gradient was continuous over the whole range of cholesterol concentrations, the lowest mortality being among men with concentrations below the lowest decile. It seems that, as with blood pressure, the average cholesterol concentration in the blood pressure, the average cholesterol concentration in the population is too high: lowest concentrations are prognostically the best. A quarter of all deaths from coronary heart disease related to cholesterol occurred among men with concentrations above the top decile, but 55% occurred among men with concentrations in the middle three fifths of the distribution; this figure of 55% could be reduced only by a policy aimed at lowering concentrations in the whole population.     

The Population-Based Risk of Need for Coronary Revascularization According to the Presence of Type 2 Diabetes Mellitus and History of Coronary Heart Disease in the Korean Population

Background

Whether diabetic patients without a history of coronary heart disease (CHD) have the same risk of CHD events as non-diabetic patients with a history of CHD remains controversial. This study aimed to determine whether type 2 diabetes mellitus (T2DM) is a coronary heart disease (CHD) equivalent in the need for coronary revascularization procedures (RVs) in the Korean population.

Methodology/Principal Findings

We followed 2,168,698 subjects who had oral anti-diabetic drugs (OADs)-taking T2DM in 2008 and/or CHD in 2007–2008 (i.e., recent CHD). We used systematic datasets from the nationwide claims database of the Health Insurance Review and Assessment service of Korea, which is representative of the whole population of Korea, from January 2007 to December 2012. The primary study endpoint was the development of need for RVs (i.e., incident CHD) after January 2009 among three groups based on their status of T2DM and recent CHD, i.e., T2DM only, recent CHD only, and both T2DM and recent CHD. After adjustment for age and sex, patients with recent CHD only had 2.14 times the risk of incident CHD (95% CI, 2.11–2.18, P<0.001) compared with patients with T2DM only. Patients with both T2DM and recent CHD demonstrated approximately 2-fold increased risk of incident CHD compared with subjects with recent CHD only (95% CI, 1.75-1.82), while 4-fold increased risk compared with subjects with T2DM only (95% CI, 3.71-3.87). The risk of incident CHD also differed according to sex and age.

Conclusions/Significance

This analysis of data from the nationwide claims database revealed that T2DM did not have a recent CHD equivalent risk in the Korean population. These results suggest that an appropriate strategy for the CHD risk stratification in diabetic patients should be adopted to manage this population.     

Changes in risk factors explain changes in mortality from ischaemic heart disease in Finland.

OBJECTIVES--To estimate the extent to which changes in the main coronary risk factors (serum cholesterol concentration, blood pressure, and smoking) explain the decline in mortality from ischaemic heart disease and to evaluate the relative importance of change in each of these risk factors. DESIGN--Predicted changes in ischaemic heart disease mortality were calculated by a logistic regression model using the risk factor levels assessed by cross sectional population surveys, in 1972, 1977, 1982, 1987, and 1992. These predicted changes were compared with observed changes in mortality statistics. SETTING--North Karelia and Kuopio provinces, Finland. SUBJECTS--14,257 men and 14,786 women aged 30-59 randomly selected from the national population register. MAIN OUTCOME MEASURES--Levels of the risk factors and predicted and observed changes in mortality from ischaemic heart disease. RESULTS--The observed changes in the risk factors in the population from 1972 to 1992 predicted a decline in mortality from ischaemic heart disease of 44% (95% confidence interval 37% to 50%) in men and 49% (37% to 59%) in women. The observed decline was 55% (51% to 58%) and 68% (61 to 74) respectively. CONCLUSION--An assessment of the data on the risk factors for ischaemic heart disease and mortality suggests that most of the decline in mortality from ischaemic heart disease can be explained by changes in the three main coronary risk factors.     

Screen detected high blood pressure under 40: a general practice population followed up for 21 years.

OBJECTIVE--To assess hypertension detected under 40 in a general practice population. DESIGN--Prospective case-control study. SETTING AND SUBJECTS--Former coal mining community in south Wales. Systematic case finding for hypertension and associated risk factors applied to a mean total population of 1945 from age 20 on a five year cycle through 21 years. Mean population aged 20-39, 227 men and 213 women. Case criteria: age < 40 and mean systolic pressure > or = 160 mm Hg or diastolic pressure > or = 100 mm Hg. Age and sex matched controls randomly sampled from the same population. MAIN OUTCOME MEASURES--Mean initial pressures and pressures at follow up in 1989 or preceding death, and all cardiovascular events. RESULTS--25 men and 16 women met criteria. Estimated five yearly inceptions were 26/1000 for men and 18/1000 for women. Male group mean initial blood pressure was 164/110 mm Hg for cases, falling to 148/89 mm Hg at follow up. Five male cases died at mean age 47.8, compared with two controls at 49.5. Female group mean initial pressure was 172/107 mm Hg for cases, falling to 145/86 mm Hg at follow up. One female case died aged 50, no controls. 10 male cases had non-fatal cardiovascular events at mean age 40.2, compared with two controls at mean age 50.5. Four female cases had non-fatal events at mean age 47.2, compared with one control aged 58. Male differences were statistically significant. CONCLUSIONS--Hypertension under 40 is dangerous, commoner in men than women, rarely secondary to classic causes, and may be controlled in general practice on a whole community basis.     

Relation of low diastolic blood pressure to coronary heart disease death in presence of myocardial infarction: the Framingham Study.

OBJECTIVE--To examine the hypothesis that a J curve relation between blood pressure and death from coronary heart disease is confined to high risk subjects with myocardial infarction. DESIGN--Cohort longitudinal epidemiological study with biennial examinations since 1950. SETTING--Framingham, Massachusetts, USA. SUBJECTS--5209 subjects in the Framingham study cohort followed up by a person examination approach. MAIN OUTCOME MEASURES--Coronary heart disease deaths and non-cardiovascular disease deaths in men and women with or without myocardial infarction relative to blood pressure. RESULTS--Among subjects without myocardial infarction non-cardiovascular disease deaths were twice to three times as common as coronary heart disease deaths. Furthermore, there was no significant relation between non-cardiovascular disease death and diastolic or systolic blood pressure. Also coronary heart disease deaths were linearly related to diastolic and systolic blood pressures. Among high risk patients (that is, people with myocardial infarction but free of congestive heart failure) death from coronary heart disease was more common than non-cardiovascular disease death. There was a significant U shaped relation between coronary heart disease death and diastolic blood pressure. Although there was an apparent U shaped relation between coronary heart disease death and systolic blood pressure, it did not attain statistical significance when controlling for age and change in systolic blood pressure from the pre-myocardial infarction level. None of the above conclusions changed when adjustments were made for risk factors such as serum cholesterol concentration, antihypertensive treatment, and left ventricular function. The U shaped relation between diastolic blood pressure and high risk subjects existed for both those given antihypertensive treatment and those not. CONCLUSIONS--These data suggest that an age and sex independent U curve relation exists for diastolic blood pressure and coronary heart disease deaths in patients with myocardial infarction but not for low risk subjects without myocardial infarction. The relation seems to be independent of left ventricular function and antihypertensive treatment.     

Value of low dose combination treatment with blood pressure lowering drugs: analysis of 354 randomised trials

Objective To determine the average reduction in blood pressure, prevalence of adverse effects, and reduction in risk of stroke and ischaemic heart disease events produced by the five main categories of blood pressure lowering drugs according to dose, singly and in combination.Design Meta-analysis of 354 randomised double blind placebo controlled trials of thiazides, β blockers, angiotensin converting enzyme (ACE) inhibitors, angiotensin II receptor antagonists, and calcium channel blockers in fixed dose.Subjects 40 000 treated patients and 16 000 patients given placebo.Main outcome measures Placebo adjusted reductions in systolic and diastolic blood pressure and prevalence of adverse effects, according to dose expressed as a multiple of the standard (recommended) doses of the drugs.Results All five categories of drug produced similar reductions in blood pressure. The average reduction was 9.1 mm Hg systolic and 5.5 mm Hg diastolic at standard dose and 7.1 mm Hg systolic and 4.4 mm Hg diastolic (20% lower) at half standard dose. The drugs reduced blood pressure from all pretreatment levels, more so from higher levels; for a 10 mm Hg higher blood pressure the reduction was 1.0 mm Hg systolic and 1.1 mm Hg diastolic greater. The blood pressure lowering effects of different categories of drugs were additive. Symptoms attributable to thiazides, β blockers, and calcium channel blockers were strongly dose related; symptoms caused by ACE inhibitors (mainly cough) were not dose related. Angiotensin II receptor antagonists caused no excess of symptoms. The prevalence of symptoms with two drugs in combination was less than additive. Adverse metabolic effects (such as changes in cholesterol or potassium) were negligible at half standard dose.Conclusions Combination low dose drug treatment increases efficacy and reduces adverse effects. From the average blood pressure in people who have strokes (150/90 mm Hg) three drugs at half standard dose are estimated to lower blood pressure by 20 mm Hg systolic and 11 mm Hg diastolic and thereby reduce the risk of stroke by 63% and ischaemic heart disease events by 46% at age 60-69.     

Determination of who may derive most benefit from aspirin in primary prevention: subgroup results from a randomised controlled trial

ObjectiveTo determine which groups of patients may derive particular benefit or experience harm from the use of low dose aspirin for the primary prevention of coronary heart disease.DesignRandomised controlled trial.Setting108 group practices in the Medical Research Council''s general practice research framework who were taking part in the thrombosis prevention trial.Participants5499 men aged between 45 and 69 years at entry who were at increased risk of coronary heart disease.ResultsAspirin reduced coronary events by 20%. This benefit, mainly for non-fatal events, was significantly greater the lower the systolic blood pressure at entry (interaction P=0.0015), the relative risk at pressures 130 mm Hg being 0.55 compared with 0.94 at pressures >145 mm Hg. Aspirin also reduced strokes at low but not high pressures, the relative risks being 0.41 and 1.42 (P=0.006) respectively. The relative risk of all major cardiovascular events—that is, the sum of coronary heart disease and stroke—was 0.59 at pressures <130 mm Hg compared with 1.08 at pressures >145 mm Hg (P=0.0001).ConclusionEven with the limitations of subgroup analyses the evidence suggests that the benefit of low dose aspirin in primary prevention may occur mainly in those with lower systolic blood pressures, although it is not clear even in these men that the benefit outweighs the potential hazards. Men with higher pressures may be exposed to the risks of bleeding while deriving no benefit through reductions in coronary heart disease and stroke.     

Intravenous diazoxide in treatment of hypertension associated with recent myocardial infarction

Twenty patients with blood pressure over 180/110 mm Hg one hour after admission to a coronary care unit with recent acute myocardial infarction were given intravenous diazoxide in a bolus of 300 mg. The average blood pressure before diazoxide was 194/122 mm Hg. Blood pressure fell considerably in all patients, though six patients required two injections. The average fall was 58 mm Hg systolic and 40 mm Hg diastolic. No patient became severely hypotensive. The heart rate increased by an average of 10 beats/min. In nine patients the electrocardiographic changes immediately after the administration of diazoxide suggested an increase in myocardial injury. Though none of the patients seemed to deteriorate clinically from the diazoxide the electrocardiographic changes suggested that the use of intravenous diazoxide to lower blood pressure in patients with acute myocardial infarction might possibly be deleterious.     

Sodium and potassium intake and blood pressure change in childhood.

OBJECTIVE--To assess the association between sodium and potassium intake and the rise in blood pressure in childhood. DESIGN--Longitudinal study of a cohort of children with annual measurements during an average follow up period of seven years. SETTING--Epidemiological survey of the population of a suburban town in western Netherlands. SUBJECTS--Cohort of 233 children aged 5-17 drawn at random from participants in the population survey. MAIN OUTCOME MEASURES--At least six annual timed overnight urine samples were obtained. The mean 24 hour sodium and potassium excretion during the follow up period was estimated for each participant and the sodium to potassium ratio calculated. Individual slopes of blood pressure over time were calculated by linear regression analysis. RESULTS--No significant association was observed between sodium excretion and the change in blood pressure over time. The mean systolic blood pressure slopes, however, were lower when potassium intake was higher (coefficient of linear regression -0.045 mm Hg/year/mmol; 95% confidence interval -0.069 to -0.020), and the change in systolic pressure was greater when the urinary sodium to potassium ratio was higher (0.356 mm Hg/year/unit; 95% confidence interval 0.069 to 0.642). In relation to potassium this was interpreted as a rise in blood pressure that was on average 1.0 mm Hg (95% confidence interval -1.65 to -0.35) lower in children in the upper part of the distribution of intake compared with those in the lower part. The mean yearly rise in systolic blood pressure for the group as a whole was 1.95 mm Hg. Urinary electrolyte excretion was not associated with diastolic blood pressure. CONCLUSION--Dietary potassium and the dietary sodium to potassium ratio are related to the rise in blood pressure in childhood and may be important in the early pathogenesis of primary hypertension.     

Medical Research Council trial of treatment of hypertension in older adults: principal results. MRC Working Party.

To establish whether treatment with diuretic or beta blocker in hypertensive older adults reduces risk of stroke, coronary heart disease, and death.Randomised, placebo controlled, single blind trial.226 general practices in the MRC general practice research framework.4396 patients aged 65-74 randomised to receive diuretic, beta blocker, or placebo. Patients had mean systolic pressures of 160-209 mm Hg and mean diastolic pressures less than 115 mm Hg during an eight week run in and were not taking antihypertensive treatment.Patients were randomised to atenolol 50 mg daily; hydrochlorothiazide 25 mg or 50 mg plus amiloride 2.5 mg or 5 mg daily; or placebo. The regimens were adjusted to achieve specified target pressures. Mean follow up was 5.8 years.Strokes, coronary events, and deaths from all causes.Both treatments reduced blood pressure below the level in the placebo group. Compared with the placebo group, actively treated subjects (diuretic and beta blocker groups combined) had a 25% (95% confidence interval 3% to 42%) reduction in stroke (p = 0.04), 19% (-2% to 36%) reduction in coronary events (p = 0.08), and 17% (2% to 29%) reduction in all cardiovascular events (p = 0.03). After adjusting for baseline characteristics the diuretic group had significantly reduced risks of stroke (31% (3% to 51%) p = 0.04), coronary events (44% (21% to 60%), p = 0.0009), and all cardiovascular events (35% (17% to 49%), p = 0.0005) compared with the placebo group. The beta blocker group showed no significant reductions in these end points. The reduction in strokes was mainly in non-smokers taking the diuretic.Hydrochlorothiazide and amiloride reduce the risk of stroke, coronary events, and all cardiovascular events in older hypertensive adults.