British Regional Heart Study: cardiovascular risk factors in middle-aged men in 24 towns

Alcohol and mortality: a review of prospective studies

Non-drinkers and heavy drinkers tend to have higher total and cardiovascular mortality rates than light or moderate drinkers. The finding is not disputed; it is the interpretation of this U-shaped curve that is controversial, and in particular the belief that light and moderate drinking protects against coronary heart disease. The British Regional Heart Study of middle-aged British men has shown that 70% of non-drinkers are ex-drinkers. Those ex-drinkers have high rates of doctor-diagnosed illnesses including heart disease, hypertension, diabetes and bronchitis as well as high prevalence rates of measured hypertension, obesity, current smoking and regular medical treatment. Over a five-year period men who were diagnosed as having heart disease, had multiple diagnoses or were put on regular medication had an increased likelihood of becoming non-drinkers or occasional drinkers. The study suggests a downward drift from heavy and moderate drinking towards non-drinking under the influence of accumulating ill health. The data strongly suggest that the observed alcohol-mortality relationships in prospective studies are produced by symptoms and disease present at the time of screening, and by the prior movement of men with such disorders into non-drinking or occasional drinking categories. The concept of a protective effect on mortality which ignores the dynamic relationship between ill health and drinking behaviour is likely to be ill-founded. A review of the major prospective studies reveals an inadequate exploration of the nature of non-drinkers, who are clearly unsuitable for use as a baseline in studies of the effects of alcohol on health.

ABO blood group and ischaemic heart disease in British men

OBJECTIVE

To establish whether ABO blood group is related to ischaemic heart disease on an individual and geographic basis in Britain.

DESIGN

Prospective study of 7662 men with known ABO blood group selected from age-sex registers in general practices in 24 British towns.

MEASUREMENTS

ABO blood group, standard cardiovascular risk factors, social class, and presence or absence of ischaemic heart disease determined at entry to study.

END POINTS

Eight year follow up of fatal and nonfatal ischaemic heart disease events achieved for 99% of study population.

RESULTS

Towns with a higher prevalence of blood group O had higher incidences of ischaemic heart disease. In individual subjects, however, the incidence of ischaemic heart disease was higher in those with group A than in those with other blood groups (relative risk 1.21, 95% confidence limits 1.01 to 1.46). Total serum cholesterol concentration was slightly higher in subjects of blood group A. No other cardiovascular risk factor (including social class) was related to blood group.

CONCLUSIONS

Blood group A is related to the incidence of ischaemic heart disease in individual subjects. Geographic differences in the distribution of ABO blood groups do not explain geographic variation in rates of ischaemic heart disease in Britain. The findings do not support the view that ABO blood group and social class are related.

Is atrial fibrillation an independent risk factor for stroke?

That non-rheumatic atrial fibrillation is an independent risk factor for cerebral infarction has not been established with certainty. The rationale underlying contemporary clinical trials of warfarin therapy for the prevention of stroke in patients who have non-rheumatic atrial fibrillation is that the majority of strokes in such patients are due to cardiogenic cerebral embolism. However, there is evidence to suggest that the increased probability of stroke attributed to this arrhythmia is due to its association with other risk factors such as hypertension, diabetes mellitus, and atherosclerosis. The question of who should be anticoagulated is a major public health issue since atrial fibrillation is present in approximately ten per cent of the general population aged 65 or more years.

Cardiovascular diseases in Chinese, Malays, and Indians in Singapore. II. Differences in risk factor levels

STUDY OBJECTIVE

The aim of the study was to examine cardiovascular risk factors to see how these might explain differences in cardiovascular disease mortality among Chinese, Malays, and Indians in the Republic of Singapore.

DESIGN

The study was a population based cross sectional survey. Stratified systematic sampling of census districts, reticulated units, and houses was used. The proportions of Malay and Indian households were increased to improve statistical efficiency, since about 75% of the population is Chinese.

SETTING

Subjects were recruited from all parts of the Republic of Singapore.

SUBJECTS

2143 subjects aged 18 to 69 years were recruited (representing 60.3% of persons approached). There were no differences in response rate between the sexes and ethnic groups.

MEASUREMENTS AND MAIN RESULTS

Data on cardiovascular risk factors were collected by questionnaire. Measurements were made of blood pressure, serum cholesterol, low and high density lipoprotein cholesterol, fasting triglycerides and plasma glucose. In males the age adjusted cigarette smoking rate was higher in Malays (53.3%) than in Chinese (37.4%) or Indians (44.5%). In both sexes, Malays had higher age adjusted mean systolic blood pressure: males 124.6 mm Hg v 121.2 mm Hg (Chinese) and 121.2 mm Hg (Indians); females 122.8 mm Hg v 117.3 mm Hg (Chinese) and 118.4 mm Hg (Indians). Serum cholesterol, low density lipoprotein cholesterol and triglyceride showed no ethnic differences. Mean high density lipoprotein cholesterol in males (age adjusted) was lower in Indians (0.69 mmol/litre) than in Chinese (0.87 mmol/litre) and Malays (0.82 mmol/litre); in females the mean value of 0.95 mmol/litre in Indians was lower than in Chinese (1.05 mmol/litre) and Malays (1.03 mmol/litre). Rank prevalence of diabetes for males was Indians (highest), Malays and then Chinese; for females it was Malays, Indians, Chinese.

CONCLUSIONS

The higher mortality from ischaemic heart disease found in Indians in Singapore cannot be explained by the major risk factors of cigarette smoking, blood pressure and serum cholesterol; lower high density lipoprotein cholesterol and higher rates of diabetes may be part of the explanation. The higher systolic blood pressures in Malays may explain their higher hypertensive disease mortality.

Geographical variations in blood pressure in British men and women

Geographical variations in blood pressure have been studied using an automatic sphygmomanometer in 2596 men and women aged 25-29, 40-44 and 55-59 living in nine British towns. In males aged 40-59, systolic blood pressure showed a range in age-adjusted town means of 9.0 mmHg (p less than 0.05); in females the difference of 8.6 mmHg was not significant (p = 0.14). Mean arterial pressure (MAP) and diastolic at age 40-59 were significantly different between towns for both sexes. Differences at age 25-29 were of a similar magnitude, and the mean town blood pressures at 25-29 correlated highly with those at 40-59 [systolic; males r = 0.74 (p less than 0.05), females r = 0.65 (p = 0.059)]. The ranking of town blood pressures in an earlier study was reflected in the present study, but stronger associations were observed with cardiovascular mortality. It is concluded that geographical blood pressure variations in Britain are established by age 25-29 years.

Inequalities in pregnancy outcome: a review of psychosocial and behavioural mediators

The purpose of this paper is to review the literature on psychosocial factors in pregnancy outcome and to present a model which attempts to integrate the findings theoretically. There are four sections. The first presents published data on the incidence of early childhood mortality and low birth weight. Changes over time and differences between countries are noted and attention is drawn to the marked inequalities between occupational groups in the British data. The second section reviews the evidence that a variety of psychosocial risk factors influence pregnancy outcome, notably social, emotional, cognitive and behavioural factors. The third section develops the theme of inequalities and examines theories which have been advanced to account for the differences in adult mortality. We argue that material deprivation goes some way towards explaining inequalities in pregnancy outcome, but that any proper account will have to explain the links between inputs and outcomes--the processes and mechanisms by which material deprivation is translated into observable mortality and morbidity. In the concluding section, we argue that some of the principal links are the psychosocial risk factors described in the second section, and we present a model which traces the pathways of mediation.

Body weight and mortality in middle aged British men: impact of smoking

OBJECTIVE

To assess the relation between body mass index and mortality in middle aged British men.

DESIGN

Men who were recruited for the British Regional Heart Study were followed up for a mean of nine years.

SETTING

General practices in 24 British towns.

SUBJECTS

7735 Men aged 40-59 years selected from the age-sex registers of one group practice in each of the 24 towns.

MAIN OUTCOME MEASURE

Mortality from cardiovascular and non-cardiovascular causes.

RESULTS

660 Of the men died. There was a U-shaped relation between body mass index and total mortality. Very lean men (less than 20 kg/m2) had by far the highest mortality followed by lean men (20-22 kg/m2) and obese men (greater than or equal to 28 kg/m2). The high mortality in lean and very lean men was due largely to non-cardiovascular causes, particularly lung cancer and respiratory disease, which are associated with cigarette smoking. In obese men deaths were more likely to be due to cardiovascular causes. There was a strong inverse association between body weight and cigarette smoking. When the pattern of mortality was examined by age, smoking habits, and pre-existing smoking related disease both very lean men and obese men consistently had an increased mortality. The U-shaped relation was most prominent in men in the oldest age group (55-59). Current smokers had a higher mortality than former smokers at virtually all values of body mass index. An increased mortality in lean men was seen only in current smokers and in men with smoking related disease. Among men who had never smoked, lean men had the lowest total mortality, thereafter mortality increased with increasing body mass index (p less than 0.01).

CONCLUSIONS

This study provides strong evidence of the impact of cigarette smoking on body weight and mortality and strongly suggests that the benefits of giving up smoking are far greater than the problems associated with the increase in weight that may occur.

Association between serum albumin and mortality from cardiovascular disease, cancer, and other causes

In a prospective study of 7735 middle-aged British men (British Regional Heart Study) 660 died during an average follow-up period of 9.2 years. There was a marked increase in mortality rate with decreasing serum albumin concentrations that persisted even after adjustment for age, social class, town of residence, cigarette smoking, serum total cholesterol, systolic blood pressure, serum total calcium, and forced expiratory volume in 1 s. When serum albumin concentration was less than 40 g/l, the mortality rate was 23/1000 per year compared with 4/1000 per year for a concentration equal to or above 48 g/l. A similar pattern was observed for cardiovascular, cancer, and other deaths. The associations persisted for cardiovascular disease and cancer even when deaths within the first five years of follow-up were excluded. These results must be interpreted with caution since there was no prior hypothesis concerning serum albumin. However, the strength of the association between serum albumin and mortality seems to be comparable with that for cigarette smoking.

Concomitants of excess coronary deaths--major risk factor and lifestyle findings from 10,359 men and women in the Scottish Heart Health Study

The Scottish Heart Health Study is a study of lifestyle and coronary heart disease risk factors in 10,359 men and women aged 40-59 years, in 22 districts of Scotland. The study was conducted during 1984-86, when Scotland had the highest national coronary heart disease mortality reported by the World Health Organisation. A self-completed questionnaire, complemented by a 40 minute visit to a survey clinic, staffed by nurses, enabled the classical major risk factors and some more newly described ones to be measured. The study emphasised quality control and representativeness, and incorporated a World Health Organisation protocol for measurement of key items to allow comparisons in place and time, and therefore also to provide a definitive baseline against which interventions can be assessed. This paper describes the overall findings. Current cigarette smokers constitute 39% of men and 38% of women, higher levels than those reported in England but lower than previous Scottish reports. Mean blood pressure levels were 134/84 mmHg for men and 131/81 mmHg in women, lower than in British studies of the 1960s and 1970s. Mean body mass index levels, 26.1 Kg/m2 in men and 25.7 Kg/m2 in women, were not high by international standards. However, mean serum cholesterol levels were 6.4 mmol/l in men and 6.6 mmol/l in women--as high as those in previous British studies and high by international standards. Levels of high density lipoprotein cholesterol, non-fasting triglycerides and fibrinogen are also reported. Physical activity both at work and in leisure time was low.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary risk factor and lifestyle variation across Scotland: results from the Scottish Heart Health Study

Between 1984 and 1986 the Scottish Heart Health Study recorded coronary risk factors and lifestyle in 10,359 men and women aged 40-59 years across 22 districts of Scotland--districts whose standardised mortality ratio for coronary heart disease in men varied from 61 in Eastwood to 136 in Monklands. This paper presents the results by district. Cigarette smoking levels showed the greatest variation, from 29% to 52% in men and 24% to 51% in women. Blood pressure means varied but were not high (129-138mmHg systolic in men, 126-137mmHg in women, 81-88mmHg diastolic in men and 77-84mmHg in women). Mean serum cholesterol values were high and varied little by district in men, (6.1 to 6.5mmol/l), although there was more variation in women (6.3 to 7.0mmol/l). Body mass index (25.3 to 26.6kg/m2 in men and 24.8 to 26.3kg/m2 in women) also varied little. Distribution of other lipids, fibrinogen, exercise levels and fruit and vegetable consumption is also described. When district mean levels of major coronary risk factors are entered into predictive formulae, cigarette smoking and blood pressure could explain part of the regional variation in mortality, but much remains unaccounted for. Nonetheless, these levels provide data for local preventive initiatives. While the overall pattern and interaction of the factors will repay further study, the high levels of serum cholesterol in all districts, and the level and variation in cigarette smoking, are a challenge for action.

Relative weight and major ischaemic heart disease events in hypertensive men

Some studies have suggested that lean hypertensive men may be at greater risk of major ischaemic heart disease (IHD) events than obese hypertensive men. The issue was examined on data from the British Regional Heart Study for 7735 middle-aged men followed up for an average of 7.5 years; during this time 443 men experienced a major IHD event. Hypertension was defined as systolic blood pressure of 160 mm Hg or above, diastolic blood pressure of 95 mm Hg or above, or receiving treatment for hypertension. For both hypertensive and normotensive men the rate of major IHD events, standardised for age and cigarette smoking, rose with increasing body mass index (BMI). The relative odds associated with a 5 kg/m2 difference in BMI (ie, a 15 kg difference in weight in men of average height [1.73 m]) were 1.30 (p = 0.02) and 1.43 (p = 0.0004) for hypertensive and normotensive men, respectively. A review of eleven prospective studies, including the British Regional Heart Study, presented in standard form for comparative purposes, suggests that lean hypertensive men are not at higher risk of major IHD events than overweight/obese hypertensive men. There seems to be no justification for the suggestion that a policy of weight reduction to lower blood pressure might be inappropriate.

Concentrations of high density lipoprotein cholesterol, triglycerides, and total cholesterol in ischaemic heart disease

OBJECTIVE

To assess the roles of serum concentrations of total cholesterol, high density lipoprotein cholesterol, and triglycerides in predicting major ischaemic heart disease.

DESIGN

Men recruited for the British regional heart study followed up for a mean of 7.5 years.

SETTING

General practices in 24 British towns.

PATIENTS

7735 Middle aged men.

END POINT

Predictive value of serum concentrations of lipids.

MEASUREMENTS AND MAIN RESULTS

At initial screening serum concentrations of total cholesterol, high density lipoprotein cholesterol, and triglycerides were determined from non-fasting blood samples. Altogether 443 major ischaemic heart disease events (fatal and non-fatal) occurred during the study. Men in the highest fifth of the distribution of total cholesterol concentration (greater than or equal to 7.2 mmol/l) had 3.5 times the risk of ischaemic heart disease than did men in the lowest fifth (less than 5.5 mmol/l) after adjustment for high density lipoprotein cholesterol concentration and other risk factors. Men in the lowest fifth of high density lipoprotein cholesterol concentration (less than 0.93 mmol/l) had 2.0 times the risk of men in the highest fifth (greater than or equal to 1.33 mmol/l) after adjustment for total cholesterol concentration and other risk factors. Men in the highest fifth of triglyceride concentration (greater than or equal to 2.8 mmol/l) had only 1.3 times the risk of those in the lowest fifth (less than 1.08 mmol/l) after adjustment for total cholesterol concentration and other risk factors; additional adjustment for high density lipoprotein cholesterol concentration made the association with ischaemic heart disease disappear.

CONCLUSIONS

Serum concentration of total cholesterol is the most important single blood lipid risk factor for ischaemic heart disease in men. High density lipoprotein cholesterol concentration is less important, and triglyceride concentrations do not have predictive importance once other risk factors have been taken into account.

Breathlessness, angina pectoris and coronary artery disease

The relation of breathlessness to angina was examined in 7,735 middle-aged British men. Among men who did not report breathlessness, the age-standardized prevalence rate of angina was 4%. In men with mild, moderate or severe breathlessness, the prevalence rates of angina were 16, 29 and 41%, respectively. The association between breathlessness and angina was independent of age or cigarette smoking, with similar relations observed in men who had never smoked. The prevalence of electrocardiograms revealing ischemia increased with the severity of breathlessness, even in men without angina or other evidence of coronary artery disease (CAD) at screening. In men with a low forced expiratory volume in 1 second, the prevalence of angina was also increased, but the association was much weaker than that observed between angina and breathlessness. After a 5-year follow-up, 25% of men severely breathless at screening but without any initial evidence of CAD had developed angina, 5% had had a heart attack (half of these were fatal) and 7% were dead from causes other than CAD. The corresponding rates for men not breathless at screening and without evidence of CAD were: 4% angina, 2.5% heart attack and 2% dead from causes other than CAD. Breathlessness appears to be an early indicator of CAD in the absence of either angina or electrocardiographic evidence of ischemia.

Coronary risk factor prevalence in a high incidence area: results from the Belfast MONICA Project

Northern Ireland remains at the top of the world mortality league for ischaemic heart disease. The Province is providing a centre for the World Health Organisation's MONICA Project. Registration of coronary heart disease events began in 1983 and the first of three population surveys took place in 1983-4. A total of 2,361 men and women aged 25-64 years was screened. Subjects were shorter and heavier than their fellow citizens in Great Britain. The estimated mean cholesterol levels in the 25-64-year-old population (5.80 mmol/l in males and 5.85 mmol/l in females) were similar to those reported from Great Britain. Although mean systolic blood pressures were lower, mild diastolic hypertension was considerably more common; cigarette smoking levels were similar. The results were consistent with those expected for an area with a high coronary heart disease mortality, with more than 80% of subjects being at increased risk in terms of the three major factors (cigarette smoking, hypertension and raised cholesterol). Public concern about coronary heart disease has grown and recently the Department of Health and Social Services (NI) has launched a 10-year prevention programme which will primarily employ a population approach.

Growth in utero, blood pressure in childhood and adult life, and mortality from cardiovascular disease

In national samples of 9921 10 year olds and 3259 adults in Britain systolic blood pressure was inversely related to birth weight. The association was independent of gestational age and may therefore be attributed to reduced fetal growth. This suggests that the intrauterine environment influences blood pressure during adult life. It is further evidence that the geographical differences in average blood pressure and mortality from cardiovascular disease in Britain partly reflect past differences in the intrauterine environment. Within England and Wales 10 year olds living in areas with high cardiovascular mortality were shorter and had higher resting pulse rates than those living in other areas. Their mothers were also shorter and had higher diastolic blood pressures. This suggests that there are persisting geographical differences in the childhood environment that predispose to differences in cardiovascular mortality.

Migration and geographic variations in ischaemic heart disease in Great Britain

The British Regional Heart Study seeks to explain the geographic variations in cardiovascular disease in Great Britain. A strong geographic gradient in the risk of a major ischaemic heart disease (IHD) event was found in 7735 middle-aged men who were followed up for 6.5 years. Regardless of where they were born, men examined in Scotland experienced the highest IHD risk, while those examined in the South of England had the lowest. The place of examination (ie, residence) was a more important determinant of the risk of a major IHD event than the place of birth. It seems unlikely that the geographic differences in IHD risk among middle-aged British men can be directly explained by their genetic inheritance or by their prenatal and postnatal diet.

Diurnal variations in serum biochemical and haematological measurements

Twenty five biochemical and haematological measurements were determined on nonfasting blood and serum samples collected between 9 am and 7 pm from a representative group of 7685 British middle-aged men. Most measurements showed significant diurnal variations, but only for bilirubin, phosphate, and triglyceride did time of day account for more than 5% of the between subject variance. Serum bilirubin concentrations showed a pronounced downward trend in the afternoon, the mean value after 6 pm being 30% lower than the mean value in the morning. Mean serum triglyceride and phosphate concentrations increased steadily through the day. Mean concentrations of potassium, haemoglobin, and haematocrit and red cell count were higher in the morning, while urea and creatinine concentrations and white cell count had higher means in the afternoon. Glucose showed a pattern consistent with short term response to meals. The effects of these diurnal trends on routine use of biochemical tests needs careful consideration, and a greater understanding of their biological mechanisms is required.

Prevention of cardiovascular disease by psychological methods

It is generally recognised that much cardiovascular disease is the result of voluntary behaviour such as smoking cigarettes, and the pursuit of stress-prone lifestyles. Since these risks are primarily behavioural, it is appropriate to attempt to alter them, and hence reduce the risk of cardiovascular disease, using psychological methods, and such methods can reduce both biological and psychological stress-related factors. Studies of healthy populations, of those at increased risk, and of patients with clear cardiovascular disease have all shown that risk-related behaviour can be altered and, in some cases, the incidence of cardiovascular disease reduced. Future research will have to extend these findings, which were often on atypical populations, and confirm reduction of cardiovascular disease.

Alcohol and mortality in British men: explaining the U-shaped curve

In a prospective study of 7735 middle-aged 7 British men, 504 of whom died in a follow-up period of 7.5 years, there was a U-shaped relationship between alcohol intake and total mortality and an inverse relationship with cardiovascular mortality, even after adjustment for age, cigarette smoking, and social class. These mortality patterns were seen in all smoking categories (with ex-smoking non-drinkers having the highest mortality) and were observed in manual but not in non-manual workers. The alcohol-mortality relationships (total and cardiovascular) were present only in men with cardiovascular or cardiovascular-related doctor-diagnosed illnesses at initial examination. The data suggest that the observed alcohol-mortality relationships are produced by pre-existing disease and by the movement of men with such disease into non-drinking or occasional-drinking categories. The concept of a "protective" effect of drinking on mortality, ignoring the dynamic relationship between ill-health and drinking behaviour, is likely to be ill founded.

The role of risk factors in heart attacks occurring in men with pre-existing ischaemic heart disease

The importance of three risk factors--serum total cholesterol, systolic blood pressure, and cigarette smoking--on the risk of new major ischaemic heart disease events in men who already have evidence of ischaemic heart disease was assessed. Data from the initial examination in a large prospective study of cardiovascular disease in middle aged men (the British Regional Heart Study) were used to separate 7710 men into three groups on the basis of a resting electrocardiogram, a standardised chest pain questionnaire, and recall of a doctor's diagnosis of angina or of a previous heart attack: (group 1) no evidence of ischaemic heart disease (75%), (group 2) evidence of ischaemic heart disease short of a definite myocardial infarction (20%), (group 3) definite myocardial infarction (6%). In the average follow up period of 7.5 years, 443 men suffered a new major event caused by ischaemic heart disease (fatal or non-fatal myocardial infarction or sudden cardiac death). Age standardised event rates were determined for each of the three groups for varying levels of the established risk factors. Cigarette smoking is strongly associated with the event rate in group 1 but in men with existing heart disease, especially group 3, differences in risk between the smoking categories were smaller. The strong relation between systolic blood pressure and event rate persisted in groups 1 and 2 but not in group 3. The positive association between serum concentration of total cholesterol and the event rate was strongest in group 1 and weaker in groups 2 and 3, though it remained highly significant. These observations, taken together with the results of previous prospective studies and intervention trials, suggest that the important association between serum total cholesterol and the risk of heart attack persists in men with pre-existing ischaemic heart disease, including myocardial infarction. Therefore, in these men the reduction of serum total cholesterol concentration may be at least as important as it is in men without evidence of ischaemic heart disease.

Blood pressure in British children: associations with adult blood pressure and cardiovascular mortality

Blood pressure was measured in 4186 children aged 5 to 7 years in 9 British towns. 3 towns had high, 3 had intermediate, and 3 had low adult blood pressure levels observed in an earlier study of middle-aged men. Significant differences between the towns were found for the children's mean systolic blood pressure (range 96.7 to 102.4 mm Hg) and diastolic pressure (range 55.9 to 60.3 mm Hg). The pattern of systolic blood pressure differences in children was similar to that observed in the study of middle-aged men (r = 0.65). The town mean systolic pressures in children show an association with standardised mortality ratios for cardiovascular disease in adults. The pattern of geographical differences in blood pressure observed in British adult men may have its origins early in life.

Changes in drinking habits in middle-aged British men

The drinking behaviour of 7735 middle-aged men drawn from general practices in 24 British towns was determined in 1978-80 and five years later in 1983-85. Those with heavier initial drinking were more likely to have reduced consumption after five years. At every level of consumption manual workers showed a greater tendency to decrease drinking than non-manual workers. Of those who became non-drinkers over the five years, 12% had been moderate or heavy drinkers. Men who were told by a doctor that they had developed ischaemic heart disease during the five years were more likely to reduce their alcohol consumption than men who remained free of ischaemic heart disease. Similarly, men who were put on regular medical treatment of any kind or who acquired two or more diagnoses of illness (including ischaemic heart disease) were more likely to become occasional or non-drinkers. Nondrinkers at both reviews had higher rates of diagnosed illness than drinkers. In particular, the ex-drinkers, who comprised 70% of non-drinkers at follow up, had higher rates of ischaemic heart disease and cardiovascular-related problems, such as high blood pressure and diabetes, than drinkers.It is essential to be aware of the tendency for moderate or heavy drinkers to reduce or stop drinking over time, particularly if illness has been diagnosed. Non-drinkers and exdrinkers should not be used as a baseline in studies relating alcohol to disease.

Height and social class in middle-aged British men

A study of 7735 middle-aged British men drawn from general practices in twenty-four towns shows that there has been a progressive increase in mean height in the men who were born between 1919 and 1939. This is true for both manual and non-manual classes, but the mean heights of the two groups are significantly different and remain widely separated over this period of time. Manual workers lag twenty years behind non-manual workers in their attained height. Data from other studies indicate that this social class difference in adult height is still present in those born up to 1960. The variation in mean height between the twenty-four towns is less marked than the variation in mean height between the social classes. After social class and age have been taken into account, a "town effect" on height is still present. If height is accepted as an indicator of socio-economic circumstances in childhood, then there is a difference in adult height between social class groups in Great Britain which does not appear to be diminishing.

Identification and treatment of risk factors for coronary heart disease in general practice: a possible screening model

A screening programme for the identification of risk factors for coronary heart disease in all patients aged 25-55 years in a general practice population was studied. The identification of risk factors included measurement of obesity, blood pressure, hypercholesterolaemia, and urinalysis, together with questions about family history, cigarette smoking, alcohol intake, and lifestyle. The patients with identified risk factors were invited to attend a lifestyle intervention clinic organised by the practice nurses and run by the health visitors, with the help of the local authority dietitian. Of 2646 (62%) patients who attended for screening, 78 (64%) of the 121 shown to have a high cholesterol concentration experienced a drop in cholesterol concentration. The mean fall in cholesterol concentration in the 78 patients who showed a positive response to intervention was 1.1 mmol/l. The study was intended as a possible flexible model for screening for coronary heart disease in general practice that could be complemented rather than replaced by opportunistic screening. The issues of organisation, cost, manpower, nonattendance, and effectiveness in a busy general practice environment are discussed.

The relationship between blood lead, blood pressure, stroke, and heart attacks in middle-aged British men

The relationship between blood lead concentration and blood pressure is examined in a survey of 7371 men aged 40 to 59 from 24 British towns. After allowance for relevant confounding variables, including town of residence and alcohol consumption, there exists a very weak but statistically significant positive association between blood lead and both systolic and diastolic blood pressure. These cross-sectional data indicate that an estimated mean increase of 1.45 mm Hg in systolic blood pressure occurs for every doubling of blood lead concentration with a 95% confidence interval of 0.47 to 2.43 mm Hg. After 6 years of follow-up, 316 of these men had major ischemic heart disease, and 66 had a stroke. After allowance for the confounding effects of cigarette smoking and town of residence there is no evidence that blood lead is a risk factor for these cardiovascular events. However, as the blood lead-blood pressure association is so weak, it is unlikely that any consequent association between lead and cardiovascular disease could be demonstrated from prospective epidemiological studies. An overview of data from this and other large epidemiological surveys provides reasonably consistent evidence on lead and blood pressure. While NHANES II data on 2254 U.S. men indicate a slightly stronger association between blood lead and systolic blood pressure, data from two Welsh studies on over 2000 men did not show a statistically significant association. However, the overlapping confidence limits for all these studies suggest that there may be a weak positive statistical association whereby systolic blood pressure is increased by about 1 mm Hg for every doubling of blood lead concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

The relationship between blood lead, blood pressure, stroke, and heart attacks in middle-aged British men

The relationship between blood lead concentration and blood pressure is examined in a survey of 7371 men aged 40 to 59 from 24 British towns. After allowance for relevant confounding variables, including town of residence and alcohol consumption, there exists a very weak but statistically significant positive association between blood lead and both systolic and diastolic blood pressure. These cross-sectional data indicate that an estimated mean increase of 1.45 mm Hg in systolic blood pressure occurs for every doubling of blood lead concentration with a 95% confidence interval of 0.47 to 2.43 mm Hg. After 6 years of follow-up, 316 of these men had major ischemic heart disease, and 66 had a stroke. After allowance for the confounding effects of cigarette smoking and town of residence there is no evidence that blood lead is a risk factor for these cardiovascular events. However, as the blood lead-blood pressure association is so weak, it is unlikely that any consequent association between lead and cardiovascular disease could be demonstrated from prospective epidemiological studies. An overview of data from this and other large epidemiological surveys provides reasonably consistent evidence on lead and blood pressure. While NHANES II data on 2254 U.S. men indicate a slightly stronger association between blood lead and systolic blood pressure, data from two Welsh studies on over 2000 men did not show a statistically significant association. However, the overlapping confidence limits for all these studies suggest that there may be a weak positive statistical association whereby systolic blood pressure is increased by about 1 mm Hg for every doubling of blood lead concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood cadmium concentrations in the general population of British middle-aged men

Blood cadmium concentrations were determined for 6919 men aged 40-59 randomly selected from general practice registers in 24 British towns. The mean and median blood cadmium were 1.9 and 1.4 micrograms/1 respectively and the distribution was highly skewed. The mean levels in non-smokers was 1.0 micrograms/l and current smokers showed a marked gradient with the daily amount smoked, with a mean of 3.9 micrograms/l in men smoking 40 or more cigarettes per day. Whereas 95% of men who never smoked had blood cadmium less than 2.0 micrograms/l, 80% of men smoking 20 or more cigarettes a day exceeded this figure. 1% of the men had blood cadmium concentrations greater than or equal to 7 micrograms/l virtually all of whom currently smoked cigarettes. Blood cadmium levels in ex-smokers were much lower than in current smokers even for those who had stopped within the past year. However, the mean levels in ex-smokers remained higher than the 'never smoked' for several years after stopping. There was little evidence that age, social class, or alcohol consumption were associated with blood cadmium levels after allowance for cigarette smoking. There is substantial geographic variation in mean blood cadmium for middle-aged men which could not be completely accounted for by smoking differences. Towns in the south and east of England all had mean levels under 2.0 micrograms/l whereas the majority of towns in other parts of Britain had mean levels greater than 2.0 micrograms/l. Possible reasons for this geographic pattern (e.g. geochemistry, industrial exposure, dietary differences) need further exploration.

The relationship of high density lipoprotein subfractions to alcohol consumption, other lifestyle factors, and coronary heart disease

Serum high density lipoprotein (HDL) levels are inversely related to the risk of coronary heart disease. Controversy exists regarding the relative importance of HDL subfractions, and few studies have related subfraction levels to lifestyle factors associated with coronary risk. We examined the relationship of the major subfractions, HDL2 and HDL3, to alcohol consumption, cigarette smoking, physical exercise, body mass index, and socioeconomic status in 88 men and 49 women aged 35-64 years. Body mass index was inversely related to HDL2-cholesterol (C), particularly in men, but had no significant relationship with HDL3-C. Cigarette smoking and degree of physical exercise were not significantly related to either HDL subfraction. Alcohol consumption had a strong positive correlation with HDL3-C in both sexes; this association was statistically significant after controlling for cigarette smoking, body mass index, and serum triglyceride. Minnesota-coded ECG abnormalities and positive responses to the WHO chest pain questionnaire were associated with lower levels of HDL-C and HDL2-C in both sexes, and significantly lowered levels of HDL3-C in men but not women. These findings suggest that HDL3-C, as well as HDL2-C, may be related to coronary risk, and indicate that the protective effects of alcohol consumption may be mediated via this subfraction.

Prevalence of ischaemic heart disease: the Caerphilly and Speedwell surveys

Mortality from ischaemic heart disease remains high in the United Kingdom, and the present report describes the prevalence of the various epidemiological manifestations of the disease in two recent community studies with a common core protocol, each containing samples of over 2000 men, carried out in South Wales (Caerphilly) and the West of England (Speedwell, Bristol). The prevalence of electrocardiographic evidence of ischaemia was similar in the two communities--8.7% of men aged 45-49 years rising to 18.6% in men aged 55-59 years in the samples from South Wales, and 8.0% and 17.2% respectively in the Bristol population. The overall prevalence of angina was 7.7% in Caerphilly and 7.8% in Speedwell in men aged 45-59 years, but symptoms of severe chest pain were more commonly reported in South Wales than in Speedwell (10.1% compared with 6.3%). The data, however, suggested that the overall prevalence of ischaemic heart disease was very similar in the two areas. The prevalence of ischaemic heart disease was compared with that found in other population studies carried out in the United Kingdom and was higher than that found when employed men only were studied. There were substantial differences in mortality between the two areas; possible reasons for this are differences in community or medical services, smoking habit, or unemployment rates.

A review of the social patterning and significance of measures of height, weight, blood pressure and respiratory function

This paper reviews evidence about the social patterning and relationship to life chances of four measures of health, development or functioning; namely height, weight, blood pressure and respiratory function. It argues that these are useful supplements to more commonly used measures of 'health' such as mortality rates, morbidity rates, or self reports of health, and recommends the increased use of such direct physical measures in routine statistics and special health surveys.

Non-participation and mortality in a prospective study of cardiovascular disease

Men who did not participate in a prospective study of cardiovascular disease (The British Regional Heart Study) were younger than the participants, more likely to be unmarried, and more likely to be less skilled workers. In the first three years of follow-up, their total mortality rate was significantly higher than that of the participants; thereafter it declined to levels not significantly different from those of the participants. This excess of early deaths could not be attributed to age. There was a small but non significant excess mortality in non-participants due to neoplasms and cardiovascular disease and a somewhat greater excess from all other causes combined. The social characteristics of the non-participant population appear to contribute to their significantly higher total mortality rate, and allowance needs to be made for this in interpreting the study findings. However the death rate from cardiovascular disease was similar in participants and non-participants, suggesting that any analysis related to this particular cause of death should not be biased by non-participation.

Social class differences in ischaemic heart disease in British men

To examine why ischaemic heart disease (IHD) mortality rates in Britain are higher in manual than in non-manual workers 7735 middle-aged men in the British Regional Heart Study were followed up for 6 years, during which time 336 men experienced a major IHD event (fatal or non-fatal myocardial infarction or sudden cardiac death). The prevalence rates of IHD at screening, were higher in manual workers. Also, the attack rate of major IHD events during follow-up was 44% higher in manual workers. Marked differences in cigarette smoking contributed substantially to the increased risk of IHD in manual workers, who also had higher levels of blood pressure, were more obese, and took much less physical activity in leisure time. Adjustment for differences in these risk factors narrowed the gap between manual and non-manual workers in attack rates of IHD. Since the risk of IHD in Great Britain is high in all social classes, there would seem to be little justification for any overall policy for prevention of IHD to focus on social class. However, anti-smoking strategies might well take into account the social class differences described.

Chronic low-level lead exposure. Its role in the pathogenesis of hypertension

Lead is a common element in the earth's crust, serving useful purposes in industry, but serving no purpose in the human body. Increase in blood pressure is an important public health problem with numerous factors contributing to many facets of the disease. The relationship of lead exposure and increased blood pressure has long been considered, but only recently critically investigated. Reports of subtle changes in calcium metabolism and renal function, as well as in vitro studies examining end-arteriolar smooth muscle contractility, link lead exposure and increased blood pressure. This paper critically examines the evidence associating chronic low-level lead exposure and increased blood pressure. The review focuses on epidemiological, clinical, and toxicological data. The epidemiological evidence is consistent with low-level exposure to lead causing an elevation in blood pressure. The strength of that association, and the dose-response characteristics, are less certain. Individual resistance and susceptibility could affect the degree of blood pressure elevation. The results of animal and in vitro studies are consistent with the epidemiological evidence, and suggest biologically plausible mechanisms for the association. The most probable mechanisms are intracellular perturbations in calcium metabolism mediated by direct lead effects at the end-arteriole, and indirect effects via renal dysfunction. Better indices of lead exposure and lead activity are needed to quantify these effects in humans. New and safer methods of chelating lead suggest interesting approaches for studying the relationship between lead and hypertension. This link could have significant implications in determining what constitutes a 'safe' level of environmental lead exposure, and whether a proportion of essential hypertension could be 'cured' by chelation therapy.

Alcohol and ischaemic heart disease in middle aged British men

The relation between alcohol intake and ischaemic heart disease was examined in a large scale prospective study of middle aged men drawn from general practices in 24 British towns. After an average follow up of 6.2 years 335 of the 7729 men had experienced a myocardial infarction (fatal or non-fatal) or sudden cardiac death. No significant relation was found between reported alcohol intake and the incidence of such events. Though the group of light daily drinkers had the lowest incidence of ischaemic heart disease events, it also contained the lowest proportion of current smokers, had the lowest mean blood pressure, had the lowest mean body mass index, and contained the lowest proportion of manual workers. These characteristics are more likely to account for the apparent protective effect of alcohol against ischaemic heart disease than a direct effect of alcohol. Compared with the effects of established risk factors alcohol seems to be quite unimportant in the development of ischaemic heart disease.

Risk of stroke in non-rheumatic atrial fibrillation

Estimates of the risk of stroke for men with non-rheumatic atrial fibrillation were obtained from two large cohort studies--the Whitehall Study of London Civil Servants and the British Regional Heart Study. The first cohort provided an estimated relative risk of stroke of 6.9 compared with controls. This increased risk confirms that of the other prospective estimate, 5.6, found in the Framingham study. In the second cohort only one of the men at risk had a stroke, and the risk estimate did not differ significantly from unity. The absolute rates of stroke in both cohorts were lower than those reported in the Framingham study, implying a lesser potential benefit from preventive measures. These lower rates should be considered in the planning of trials. The risk of stroke was significantly associated with raised systolic or diastolic blood pressure but not with age or coronary heart disease.

Giving up smoking and the risk of heart attacks. A report from The British Regional Heart Study

In a prospective study of 7735 middle-aged men, both current and ex-cigarette-smokers had a risk of a major IHD event, within an average 6.2 years of screening, more than twice that in men who had never smoked cigarettes; men who had given up smoking more than 20 years ago still had an increased risk. This excess risk among ex-smokers is only to a small extent explained by their higher blood pressure, serum total cholesterol, and body-mass index. An increased prevalence of IHD in men who had recently given up smoking also made a small contribution to excess risk. In both current and former cigarette smokers, the number of years a man had smoked cigarettes ("smoking-years") was the clearest indicator of IHD risk due to cigarettes. The major benefit of giving up smoking may lie in halting the accumulation of smoking years.

A randomised controlled trial to investigate the effect of a high fibre diet on blood pressure and plasma fibrinogen

Two hundred and one subjects (147 men and 54 women) were randomly allocated to either a high cereal fibre diet or a low cereal fibre diet for four weeks. Each group then followed the alternative diet for a further four weeks. Cereal fibre intakes were 19g/d (31 g/d 21 g/d total fibre) and 6g/d (19g/d total fibre) on the high and low fibre diets respectively (p less than 0.001). Energy, protein, fat, carbohydrate, and alcohol intakes calculated from weighed intake records did not differ between the two diets, although there was a slight difference in body weight, the mean being 0.3 kg heavier at the end of the high fibre period. The high cereal fibre diet had no detectable effect on blood pressure or plasma fibrinogen.

Serum uric acid, serum glucose and diabetes: relationships in a population study

The relationships between serum uric acid, serum glucose and diabetes have been examined in a survey of 7735 middle-aged men drawn at random from general practices in 24 British towns. There was a positive relationship between serum glucose and serum uric acid concentrations up to about 8.0 mmol/l; at higher levels of glucose, serum uric acid decreased. Uric acid levels were significantly reduced in insulin-dependent diabetics and in those on oral hypoglycaemics and also in 'non-diabetics' with casual glucose levels greater than 10 mmol/l. Both uric acid and glucose concentrations were positively related to body mass index; only uric acid was positively related to alcohol intake. Men on antihypertensive treatment had raised levels of uric acid (significant) and glucose (non-significant). The positive relationship between serum uric acid and serum glucose could not be explained by associations with body mass index, alcohol intake, age, social class, gout or treatment for hypertension. It probably reflects the biochemical interaction between serum glucose and purine metabolism, with increased excretion of uric acid during hyperglycaemia and glycosuria.

The use of microcomputers for data management in a large epidemiological survey

A data management system designed around microcomputers and commercial software packages was employed for a large epidemiological study. Management involved the tracking of subjects through several stages of the study and the generation of subject listings, personalized letters of invitation, daily worklists for the field teams, and a checklist for the laboratories. These processes were controlled using a continually updated subject data base which in final form provided the core of the management system for the collected data. Data management presented major problems because of the volume of data which were received from several sources over a period of months. A key feature to emerge was the importance of an accurate serial number on all items for which a check digit was employed. The system had a short development time and was found to be inexpensive and flexible and to cope easily with the demands made of it.

Psychosocial aspects of coronary heart disease

Attention is drawn to studies which throw doubt upon the importance of nutrition and smoking in the etiology of coronary heart disease (CHD). The main part of the review deals with psychosocial research in the field of CHD. A number of studies show that there is a clearcut association between life style, life events, social class, economic cycles, culture and CHD. The modern coronary epidemic is related to the economic boom which the US experienced during the 1940-60s and which followed a decade later in Western Europe. The later decline of CHD is related to the economic stagnation that took place in the US at the end of the 1960s. Obviously, risk factors must be seen in a cultural perspective, and the moderating effects of social support should be taken into account.

The Tromsø heart study: alcoholic beverages and coronary risk factors

Frequency of beer, wine, and spirits drinking and inebriation by alcohol were associated with serum lipids and blood pressure in 14,667 free-living men and women aged 20 to 54 years. Regression analysis including several background variables revealed that alcohol was more "favourably" associated with coronary risk factors than previously reported, due to the small consumption of alcohol in the population (only 2.0% of men and 0.3% of women reported drinking every day) or to unknown confounding factors: wine (p less than 0.05) and inebriation (p less than 0.01) were inversely related with total cholesterol in women; the strong positive relation with HDL-cholesterol in both sexes previously reported was confirmed; beer (p less than 0.05) and inebriation p(less than 0.05) in men and spirits (p less than 0.01) in women seemed to decrease triglycerides; and a new observation may be the negative association between wine and blood pressure (systolic p less than 0.01 in both sexes) as opposed to the positive relation with beer (p less than 0.01 both pressures in men) and spirits (p less than 0.05 systolic pressure and p less than 0.01 diastolic pressure in men and p less than 0.05 diastolic pressure in women). Women showed more "favourable effects" of alcohol than men, and one reason may be that they drank less often. Wine gave lower risk factor readings than beer, and especially lower than spirits.

Identifying men at high risk of heart attacks: strategy for use in general practice

A strategy was devised for identifying men at high risk of acute myocardial infarction or sudden ischaemic death. A risk score was devised using cigarette smoking, mean blood pressure, recall of ischaemic heart disease or diabetes mellitus diagnosed by a doctor, history of parental death from "heart trouble," and the presence of angina reported on a questionnaire. The top fifth of the score distribution identified 53% of ischaemic heart disease cases--that is, men who subsequently experienced major ischaemic heart disease over the next five years. The addition of serum total cholesterol concentration and electrocardiographic evidence only slightly improved prediction (to 59%) and would have considerably increased the cost and effort of screening. Using this risk score on an opportunistic basis could be particularly valuable in general practice. Management of this high risk group is regarded as appropriate medical care and is complementary to the population approach to preventing ischaemic heart disease. Such a strategy for reducing the incidence of and mortality from ischaemic heart disease in men at high risk would also increase professional and public awareness of the need for preventive action.

Long-term trends in biochemical data obtained from two population surveys

A study has been made of the variations in monthly mean values of 10 serum constituents in subjects participating in two partly-concurrent long-term epidemiological surveys. Closely similar patterns of variation were found in men in both surveys and in men and women in one survey. During the 6 years of the study, four types of variation of the monthly mean concentrations were identified in varying combinations: abrupt changes of less than 2% not detected by quality control procedures; a gradual drift in mean value; haphazard variations in mean values; and seasonal variations in bilirubin and urea, identical in men and women. The implications of these findings for the design of long-term epidemiological surveys, and the criteria for designating variations as seasonal, are discussed.

Lipoprotein abnormalities in insulin-dependent diabetes mellitus

Despite the increased risk of atherosclerosis in diabetes mellitus, levels of serum cholesterol, triglycerides, low-density-lipoprotein (LDL) cholesterol, and high-density-lipoprotein (HDL) cholesterol were similar in 57 men with insulin-dependent diabetes mellitus (IDDM) and 81 non-diabetic controls. However, substantially lower serum levels of apolipoprotein B, the principal apolipoprotein of LDL, and a concomitant increase in the cholesterol-loading of apolipoprotein B were found in IDDM. The likely changes in LDL density and particle size resulting from this compositional abnormality might lead to accelerated atherogenesis analogous to that seen in type III hyperlipoproteinaemia. In addition, there was an increase in the concentration of cholesterol in the smaller, denser, HDL3 subfraction of serum HDL in IDDM.

The relation of social class to risk factors, rehabilitation, compliance and mortality in survivors of acute coronary heart disease

We studied 299 consecutive male 28-day survivors of unstable angina or myocardial infarction aged under 60 years to examine the relationship between social class and initial risk factors, change in risk-factors at one year follow-up, return to work, and 3-year mortality. There was a significant correlation between smoking on admission and social class, with 80% of lower and 31% of upper classes being current smokers. Daily cigarette consumption among smokers was significantly higher in lower-class patients. Lower-class patients also had a significantly higher weekly alcohol intake. Although the proportion of hypertensives did not vary with social class, mean in-hospital blood pressure was higher in lower-class patients. Social class bore no relationship to amount of leisure exercise, serum cholesterol or degree of overweight. There was a 90% 1-year return to work overall, and while there was no relationship between social class and eventual re-employment, lower-class patients took significantly longer to return to work. There were highly significant associations between social class and successful smoking cessation, increase in leisure exercise and weight reduction over the first year after discharge. There was no significant association between social class and 3-year mortality.