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Biomedical subjects

A G Shaper

Publications and source records attributed to A G Shaper.

At least 91 records · Page 5Linked to original sources
PubMed1995

Factors determining case fatality in myocardial infarction "who dies in a heart attack"?

OBJECTIVE: To examine the determinants of case fatality in the first major ischaemic heart disease event (heart attack) after screening. METHODS: Prospective study of 7735 middle aged men drawn from general practices in 24 British towns. RESULTS: During 11.5 years follow up there were 743 major ischaemic heart disease events of which 302 (40.6%) were fatal within 28 days of onset. Previous definite myocardial infarction or stroke and age at time of event were most strongly associated with case fatality. In men with no previous myocardial infarction or stroke, after adjustment for a range of risk factors, antihypertensive treatment (odds ratio (OR) = 1.97, P < 0.05), arrhythmia (OR = 1.93, P = 0.06), increased heart rate (OR = 2.03, P = 0.06), and diabetes (OR = 2.61, P = 0.07) were associated with increased case fatality. High levels of physical activity (OR = 0.53, P < 0.05) and moderate drinking (16-42 units/week) (OR = 0.61, P < 0.05) were associated with lower case fatality, although moderate drinking was not associated with a lower incidence of major ischaemic heart disease events. Current smoking, serum total cholesterol, and systolic blood pressure were not significantly associated with case fatality. In men with previous myocardial infarction or stroke, arrhythmia and to a lesser degree antihypertensive treatment, moderate or heavy drinking, and diabetes were associated with higher case fatality. CONCLUSION: These findings suggest that physical activity may be an important modifiable factor influencing the incidence of ischaemic heart disease and the chance of survival in men without a previous heart attack or stroke. Arrhythmia, increased heart rate, diabetes, and treatment for hypertension are also areas of concern.

Adult↗
PubMed1995

Respiratory function and risk of stroke.

BACKGROUND AND PURPOSE: This report examines the relationship between lung function and risk of major stroke events (fatal and nonfatal). METHODS: We completed a prospective study of 7735 men aged 40 to 59 years at screening selected at random from one general practice in each of 24 British towns. RESULTS: During the mean follow-up period of 14.8 years, there were 277 major stroke events in the 7650 men with data on forced expiratory volume in 1 second (FEV1). After exclusion of 499 men with definite myocardial infarction, stroke, or atrial fibrillation at screening, 7151 men experienced 239 major stroke events. Lower levels of FEV1 were associated with a significant increase in risk of stroke even after adjustment for age, smoking, social class, physical activity, alcohol intake, systolic blood pressure, antihypertensive treatment, diabetes, and preexisting ischemic heart disease. Relative risk in the low third (< 3.10 L) versus high third (> 3.65 L) was 1.4 (95% confidence interval, 1.0 to 2.0). The inverse association between FEV1 and stroke was only apparent in older men, current nonsmokers, hypertensive men, and men with preexisting ischemic heart disease. Lower FEV1 was associated with higher rates of stroke in hypertensive men irrespective of smoking status. Inclusion of FEV1 in a risk score for stroke provided only a small increase in the absolute risk or the yield of cases in the top fifth of the score distribution during the follow-up period. CONCLUSIONS: Lower levels of FEV1 are associated with an increased risk of stroke in those already at high risk, eg, those with ischemic heart disease or hypertension. However, the association is not strong enough to warrant the use of FEV1 in making clinical decisions regarding the treatment of hypertension as it relates to the prevention of stroke.

Adult↗
PubMed1995

Serum bilirubin and risk of ischemic heart disease in middle-aged British men.

The possibility that low concentrations of serum bilirubin may be associated with increased risk of ischemic heart disease has been examined in a prospective study of 7685 middle-aged British men. During 11.5 years there were 737 major ischemic heart disease (IHD) events. A U-shaped relationship was observed between serum bilirubin and risk of IHD. Low bilirubin was associated with several cardiovascular risk factors, in particular smoking, low concentrations of high-density lipoprotein cholesterol, low forced expiratory volume in 1 s, and low serum albumin. The U-shaped relationship persisted even after adjusting for several risk factors. Compared with men in the lowest fifth of the distribution (bilirubin < 7 mumol/L), those in the middle range (8-9 mumol/L) showed a 30% reduction in relative risk [RR = 0.68 (95% confidence intervals 0.51-0.89)] in IHD, whereas men in the top fifth (> 12 mumol/L) showed similar risk to the lowest fifth [RR = 0.99 (95% confidence intervals 0.73-1.34)], which persisted after exclusion of men with bilirubin > 17 mumol/L. The significance of this U-shaped relationship is unclear, but it could be interpreted as support for the role of endogenous antioxidants in the etiology of IHD.

Adult↗
PubMed1995

Resting electrocardiogram and risk of coronary heart disease in middle-aged British men.

OBJECTIVE: To examine the relation between resting electrocardiographic (ECG) abnormalities and risk of coronary heart disease (CHD). DESIGN AND SETTING: This was a prospective study of 7735 middle-aged men aged 40-59 years at entry (British Regional Heart Study). At baseline assessment each man completed a modified World Health Organization (WHO) (Rose) chest-pain questionnaire, gave details of his medical history and had a three-lead orthogonal electrocardiogram recorded. "Symptomatic CHD' refers to a history of anginal chest pain and/or a prolonged episode of central chest pain on WHO questionnaire and/or recall of a doctor diagnosis of CHD (angina or myocardial infarction). MAIN OUTCOME MEASURES: These were the first major CHD events, i.e. fatal CHD and non-fatal myocardial infarction, occurring during 9.5 years of follow-up. RESULTS: Of 611 first major CHD events during follow-up, 243 (40%) were fatal. After adjustment for age, other ECG abnormalities and symptomatic CHD, the ECG abnormalities most strongly associated with risk of a major CHD event were definite myocardial infarction (relative risk 2.5; 95% confidence interval 1.8-7.5) and definite myocardial ischaemia (1.9; 1.1-2.9). Other ECG abnormalities independently associated with a statistically significant increase in risk were left ventricular hypertrophy (2.2; 1.5-3.3), left axis deviation (1.3; 1.1-1.6) and ectopic beats, particularly if these were ventricular (1.6; 1.1-2.4). Three ECG abnormalities associated with a marked increase in CHD case-fatality rate were pre-existing myocardial infarction (67%), major conduction defect (71%) and arrhythmia (67%); the rate in men with none of these abnormalities was 32%. The relative risks associated with each ECG abnormality were similar in men with and without symptomatic CHD. The increase in risk in the presence of symptomatic CHD (2.4-fold) and ECG evidence of definite myocardial infarction (2.5-fold) was similar; the presence of both factors increased risk more than six-fold. The most serious ECG abnormalities-definite myocardial infarction and ischaemia-were useful predictors of future major CHD events only in men with symptomatic CHD. CONCLUSION: The prognostic importance of major ECG abnormalities is strongly influenced by the presence of symptomatic CHD. In men with symptomatic CHD the resting electrocardiogram may help to define a group at high risk who may benefit from intervention. However, it has little or no value as a screening tool in middle-aged men without symptomatic CHD.

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PubMed1994

Loss of employment and mortality.

OBJECTIVE: To assess effect of unemployment and early retirement on mortality in a group of middle aged British men. DESIGN: Prospective cohort study (British Regional Heart Study). Five years after initial screening, information on employment experience was obtained with a postal questionnaire. SETTING: One general practice in each of 24 towns in Britain. SUBJECTS: 6191 men aged 40-59 who had been continuously employed for at least five years before initial screening in 1978-80: 1779 experienced some unemployment or retired during the five years after screening, and 4412 remained continuously employed. MAIN OUTCOME MEASURE: Mortality during 5.5 years after postal questionnaire. RESULTS: Men who experienced unemployment in the five years after initial screening were twice as likely to die during the following 5.5 years as men who remained continuously employed (relative risk 2.13 (95% confidence interval 1.71 to 2.65). After adjustment for socioeconomic variables (town and social class), health related behaviour (smoking, alcohol consumption, and body weight), and health indicators (recall of doctor diagnoses) that had been assessed at initial screening the relative risk was slightly reduced, to 1.95 (1.57 to 2.43). Even men who retired early for reasons other than illness and who appeared to be relatively advantaged and healthy had a significantly increased risk of mortality compared with men who remained continuously employed (relative risk 1.87 (1.35 to 2.60)). The increased risk of mortality from cancer was similar to that of mortality from cardiovascular disease (adjusted relative risk 2.07 and 2.13 respectively). CONCLUSIONS: In this group of stably employed middle aged men loss of employment was associated with an increased risk of mortality even after adjustment for background variables, suggesting a causal effect. The effect was non-specific, however, with the increased mortality involving both cancer and cardiovascular disease.

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PubMed1994

Alcohol and coronary heart disease: a perspective from the British Regional Heart Study.

BACKGROUND: A number of studies have shown that light or moderate alcohol intake is associated with a reduced incidence of coronary heart disease (CHD) compared with non-drinkers. There is controversy as to whether this is due to a specific protective effect of alcohol or whether the increased risk of CHD in non-drinkers is due to selective migration of high-risk subjects from drinking into non-drinking categories. METHODS: A prospective study of men aged 40-59 years drawn at random from one general practice in each of 24 British towns, and followed for cardiovascular morbidity and all-cause mortality over a 9.5-year period. RESULTS: There was a shallow U-shaped relationship between alcohol intake and all major CHD events and a strong inverse association with fatal CHD events. In men with no evidence of CHD at screening, despite a 28% (non-significant) reduction in the relative risk of fatal CHD events in men drinking 2-6 drinks/day, the difference in absolute rates of CHD between the drinking categories was small. Men with symptomatic CHD showed a strong inverse association between alcohol and all major CHD events and fatal CHD events. In men without a doctor diagnosis of cardiovascular disorder, those drinking 2-6 drinks/day showed a 34% (non-significant) reduction in relative risk of CHD death compared to occasional drinkers but little reduction in total cardiovascular mortality and no reduction in all-cause mortality. CONCLUSION: These findings provide weak support for the protective effect of alcohol on CHD and no encouragement for regular moderate drinking on the grounds of benefit to health.

Adult↗
PubMed1994

Environmental factors in the development of essential hypertension.

Hypertension is predominantly a disorder of populations in which the fundamental problem is the tendency for blood pressure to rise with age. This phenomenon, which varies markedly across populations, is determined largely by environmental factors. We argue that the most important factors in the development of hypertension at the population level are calorie excess (as manifest by obesity), high salt intake, low potassium intake, physical inactivity, heavy alcohol consumption and psychosocial stress. Potential interactions between these factors (and the genetic endowment) are emphasized. We consider data from studies of blood pressure in children and adolescents and from intervention studies. The hypothesis that essential hypertension is initiated in fetal life is reviewed briefly. It is clear that the current high risk approach to prevention should be supplemented by a population based approach. There is controversy however regarding the value of certain interventions, such as salt restriction, at the population level. Ultimately community intervention trials will be required to resolve these issues.

Alcohol Drinking↗
PubMed1994

Haematocrit, hypertension and risk of stroke.

OBJECTIVES: To assess the relationship between haematocrit and risk of stroke. DESIGN: Prospective study of a cohort of men followed up for 9.5 years. SETTING: General practices in 24 towns in England, Scotland and Wales (British Regional Heart Study). SUBJECTS: A total of 7735 men aged 40-59 years at screening, selected at random from one general practice in each of 24 towns. MAIN OUTCOME MEASURES: Fatal and non-fatal strokes. RESULTS: During a follow-up period of 9.5 years for all men there were 123 stroke events (33 fatal) in the 7346 men in whom the haematocrit level had been determined. In the cohort as a whole, risk of stroke was significantly raised at haematocrit levels > or = 51% (relative risk [RR] = 2.5; 95% confidence intervals [CI] 1.2-5.0) after adjustment for age, social class, smoking, body mass index, physical activity, presence of diabetes and pre-existing ischaemic heart disease. Further adjustment for systolic blood pressure did not attenuate this association (RR = 2.4; 95% CI 1.2-4.9). A raised haematocrit was associated with an increase of stroke only in men with hypertension (systolic blood pressure > or = 160 mmHg or diastolic blood pressure > or = 90 mmHg or on regular antihypertensive treatment). No increased risk of stroke was seen at the higher haematocrit level (> or = 51%) in normotensive men. At haematocrit levels below 51%, hypertension was associated with a three-fold increase in risk of stroke compared with normotension (RR = 3.4, 95% CI 2.3, 5.1). At haematocrit levels > or = 51%, hypertension was associated with a nine-fold increase in risk of stroke compared with normotension (RR = 9.3; 95% CI 4.2, 21.0). Exclusion of men receiving regular antihypertensive therapy did not alter the strong associations seen. CONCLUSION: The data suggest that an elevated haematocrit is an independent risk factor for stroke and that it interacts synergistically with elevated blood pressure.

Adult↗
PubMed1994

Carotid intima-media thickness: correlation with the British Regional Heart Study risk score.

OBJECTIVES: The thickness of the intima-media (IMT) layer of the common carotid artery is a marker of severe and extensive coronary artery disease and it has been reported that it is related to the presence of risk factors for atherosclerosis. The purpose of this study was to establish whether the IMT correlates with the British Regional Heart Study (BRHS) risk score which identifies a large proportion of men who may experience a major ischaemic heart disease event within 5 years of initial screening. SUBJECTS: High resolution ultrasonography was used to measure the thickness of the intima-media layer in 89 individuals. The BRHS risk score of these individuals was also recorded. MAIN OUTCOME MEASURES: Correlation between the carotid IMT and the BRHS score. RESULTS: The IMT was linearly related to the BRHS score (r = 0.56; P < 0.001). There was a highly significant difference between the mean IMT in individuals with a risk score greater and those with a risk score lesser than the 80th percentile (P < 0.001). CONCLUSION: It is concluded that the IMT may be a useful surrogate end-point or biological marker of coronary artery disease and might be considered for use in prospective studies and clinical trials.

Adult↗
PubMed1994

Ischaemic heart disease: association with haematocrit in the British Regional Heart Study.

OBJECTIVES: To assess the relationship between haematocrit and risk of major ischaemic heart disease events. DESIGN: Prospective study of a cohort of men followed up for 9.5 years. SETTING: General practices in 24 towns in England, Wales, and Scotland (British Regional Heart Study). SUBJECTS: Altogether 7735 men aged 40-59 years at screening, who were selected at random from one general practice in each of 24 towns, were studied. MAIN OUTCOME MEASURES: Fatal and nonfatal ischaemic heart disease events. RESULTS: Risk of major ischaemic heart disease events was significantly increased at haematocrit levels of > or = 46.0%. Men with raised haematocrit (> or = 46.0%) showed a 30% increase in relative risk (RR) of major ischaemic heart disease events (RR = 1.32; 95% confidence intervals (CI) 1.10,1.57, p < 0.01) compared with those with values below 46.0%, even after adjustment for age, social class, smoking, body mass index, physical activity, blood cholesterol, lung function (FEV1), and pre-existing evidence of ischaemic heart disease. Further adjustment for systolic blood pressure reduced the risk slightly (RR = 1.27; 95% CI 1.06,1.51, p = 0.02) but it remained significant. The relationship was seen in men with and without pre-existing evidence of ischaemic heart disease. The study suggests that an increased haematocrit level plays a part in the development of major ischaemic heart disease events.

Adult↗
PubMed1994

Asymptomatic hyperglycaemia and major ischaemic heart disease events in Britain.

OBJECTIVE: To examine the association between non-fasting serum glucose concentrations and major ischaemic heart disease (IHD) events (fatal and non-fatal myocardial infarction). DESIGN: A prospective study. SUBJECTS: A population based sample of 7735 middle aged British men. Known diabetics, men with a glucose concentration > or = 11.1 mmol/l at screening, and hypertensive patients taking regular medication were excluded from the analysis. With exclusions (n = 509) and missing glucose values (n = 49), there were 7177 men available for analysis. MAIN OUTCOME MEASURES: Major IHD events (fatal and non-fatal myocardial infarction) during 9.5 years follow up on all men. RESULTS: There were 505 major IHD events, 222 fatal and 283 non-fatal, in the 7177 men studied. There was a non-linear relation between the glucose concentration and the risk (per 1000 men per year) of all major IHD events and fatal IHD events, with the excess risk in the upper quintile of the glucose distribution (> or = 6.1 mmol/l). The unadjusted relative risks (RR) in the upper glucose concentration quintile compared with the first to the fourth quintiles combined were 1.4 (95% CI 1.1, 1.7) for all events and 1.3 (95% CI 1.0, 1.7) for fatal events. Adjustment for age, smoking, occupational status, body mass index, physical activity, systolic blood pressure, total and high density lipoprotein cholesterol, and triglyceride concentrations had a minimal effect on these relative risk estimates. This non-linear relationship between the serum glucose concentration and the risk of a major IHD event was observed in men with no evidence of IHD at screening (n = 5518) but not in men with IHD (n = 1659). In the former group, the RR (adjusted for major coronary risk factors) for all major IHD events in the upper quintile relative to the lower quintiles combined was 1.5 (95% CI 1.2, 2.0) and for fatal IHD events was 1.8 (95% CI 1.1, 2.6). CONCLUSION: These data suggest that asymptomatic hyperglycaemia is an independent risk factor for major IHD events.

Adult↗
PubMed1994

The association between heart rate and blood pressure, blood lipids and other cardiovascular risk factors.

BACKGROUND: Several studies have shown that an elevated heart rate is associated with an increased risk of ischaemic heart disease. The aim of this study was to examine the relationship between heart rate, blood pressure, blood lipids and other cardiovascular risk factors in middle-aged men. METHODS: A total of 7735 men, aged 40-59 years at screening, were selected at random from one of the general practices in each of the 24 towns participating in the cross-sectional (screening) phase of the British Regional Heart Study. Blood pressure and levels of blood lipids (serum total cholesterol, high-density-lipoprotein (HDL) cholesterol and triglycerides) and blood glucose were measured. RESULTS: All men with pre-existing evidence of ischaemic heart disease and those on regular antihypertensive treatment were excluded from the analysis. In the remaining 5597 men, heart rate showed a strong positive correlation with cigarette smoking and body-mass index and decreased significantly at higher levels of physical activity and FEV1 (forced expiratory volume in 1 s). These associations remained significant after adjustment for each other. Age, alcohol intake and social class were not independently associated with heart rate. There was a significant positive association between heart rate and systolic and diastolic blood pressures, levels of blood cholesterol, triglycerides and blood glucose and a significant inverse association between heart rate and HDL-cholesterol levels, even after adjusting for the above confounding factors. After further adjustment for each of the other physiological variables, heart rate remained independently associated with diastolic and systolic blood pressures and levels of triglycerides and blood glucose. The relationship between heart rate and levels of total cholesterol and HDL cholesterol appeared to be secondary to its association with triglyceride levels. The association between body-mass index and heart rate diminished after further adjustments for systolic blood pressure, suggesting that the primary effect of body weight is on blood pressure rather than on heart rate. CONCLUSION: Our findings indicate that elevated heart rate is associated with hypertension and with an atherogenic lipoprotein profile and support the suggestion that disturbance of the autonomic nervous system may underlie these associations.

Adult↗
PubMed1994

Serum sodium concentration and risk of stroke in middle-aged males.

BACKGROUND AND METHODS: Clinical disturbances of the circulating sodium concentration are both a cause and a consequence of cerebrovascular disease. We examined the relationship between serum sodium level and risk of stroke and major ischaemic heart disease in a prospective study of 7690 middle-aged males drawn from general practices in 24 British towns followed over a 9.5-year period. RESULTS: The mean serum sodium level was 141.5 mmol/l and 375 males on antihypertensive treatment were excluded from the analyses. A significant inverse trend was seen between serum sodium and risk of stroke up to 144 mmol/l; above this the risk of stroke was increased. Those with levels of 143-144 mmol/l showed over a 70% reduction in risk of stroke compared with those with levels of < or = 140 mmol/l. The inverse relationship between sodium and stroke up to 144 mmol/l was seen in males with and without pre-existing ischaemic heart disease or stroke, in normotensives and untreated hypertensives, and in non-smokers and current smokers. A weak but significant inverse association was seen between serum sodium and diastolic but not systolic blood pressure. The association between serum sodium level and stroke remained significant after adjustment for diastolic blood pressure and other factors associated with stroke: age, smoking, social class, body mass index, physical activity, heavy drinking, presence of diabetes, blood glucose and pre-existing ischaemic heart disease. No association was seen between serum sodium level and risk of ischaemic heart disease after adjustment for other risk factors. All-cause and non-cardiovascular mortality were significantly increased at serum sodium levels of < or = 138 mmol/l, probably due to an association between lung cancer and hyponatraemia. CONCLUSION: These findings suggest that sodium concentration may be related to risk of stroke even at levels of sodium usually regarded as normal.

Adult↗
PubMed1994

Haematocrit: relationships with blood lipids, blood pressure and other cardiovascular risk factors.

The relationship between haematocrit and cardiovascular risk factors, particularly blood pressure and blood lipids, has been examined in detail in a large prospective study of 7735 middle-aged men drawn from general practices in 24 British towns. The analyses are restricted to the 5494 men free of any evidence of ischaemic heart disease at screening. Smoking, body mass index, physical activity, alcohol intake and lung function (FEV1) were factors strongly associated with haematocrit levels independent of each other. Age showed a significant but small independent association with haematocrit. Non-manual workers had slightly higher haematocrit levels than manual workers; this difference increased considerably and became significant after adjustment for the other risk factors. Diabetics showed significantly lower levels of haematocrit than non-diabetics. In the univariate analysis, haematocrit was significantly associated with total serum protein (r = 0.18), cholesterol (r = 0.16), triglyceride (r = 0.15), diastolic blood pressure (r = 0.17) and heart rate (r = 0.14); all at p < 0.0001. A weaker but significant association was seen with systolic blood pressure (r = 0.09, p < 0.001). These relationships remained significant even after adjustment for age, smoking, body mass index, physical activity, alcohol intake, lung function, presence of diabetes, social class and for each of the other biological variables; the relationship with systolic blood pressure was considerably weakened. No association was seen with blood glucose and HDL-cholesterol. This study has shown significant associations between several lifestyle characteristics and the haematocrit and supports the findings of a significant relationship between the haematocrit and blood lipids and blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Physical activity, hypertension and risk of heart attack in men without evidence of ischaemic heart disease.

The role of hypertension in the increased rate of heart attack reported in vigorously active subjects was examined in a large prospective study of 7735 middle-aged men drawn from general practices in 24 British towns (The British Regional Heart Study). Analyses were restricted to 5694 men with no evidence of pre-existing ischaemic heart disease or stroke at screening, in whom there were 311 major ischaemic heart disease events after 9.5 years follow-up. Risk of major ischaemic heart disease events decreased significantly with increasing physical activity to levels of moderate/moderately vigorous activity, with a 50% reduction in risk compared with inactive men after adjustment for age, body mass index, smoking, heavy drinking, social class and blood cholesterol. However, at the highest level of physical activity (vigorous group) risk of major ischaemic heart disease events was increased above that seen in the moderate/moderately vigorous group (rr = 1.68, P = 0.05). When separated into normotensives (n = 3888) and hypertensives (n = 1806; SBP > or = 160 mmHg or DBP > or = 90 mmHg or on regular antihypertensive treatment), the increased risk of major ischaemic heart disease events in the vigorous group was only evident in hypertensive men. They showed more than a twofold increase in risk compared with the moderate and moderately vigorous group (rr = 2.7, P < 0.05). In normotensive men, risk was significantly lowered in those engaged in moderate activity with no further decline in rate of heart attack at increasing levels of physical activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗