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Biomedical subjects

A G Shaper

Publications and source records attributed to A G Shaper.

At least 127 records · Page 7Linked to original sources
PubMed1991

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.

Alcohol Drinking↗
PubMed1991

Self-assessment of health status and mortality in middle-aged British men.

In a prospective study of 7725 middle-aged British men, 357 of whom died in an average follow-up period of four years, self-assessment of health status was strongly associated with mortality. Men who reported poor health had an eight-fold increase in total mortality compared with those reporting excellent health. Those perceiving fair or poor health were older, more likely to be manual workers and cigarette smokers, more likely to be thin and to be heavy drinkers or to have given up drinking in the past five years. They were also more likely to recall multiple diagnoses and to be on regular medication. Half of those with poor perceived health had chest pain on exertion (angina), one-third had experienced severe chest pain (possible myocardial infarction) half were breathless on exertion and 80% had been off work for more than a month in recent years. At all age levels between 45 and 64 years, and in both manual and non-manual workers, mortality was twice as high in men reporting fair or poor health than in men reporting excellent or good health. In both men with and without recall of at least one major diagnosis, fair or poor perceived health was associated with a two fold increase in age-adjusted mortality rate. In both groups this increased mortality was to a large extent accounted for by the increase in the prevalence of adverse characteristics such as regular medication, chest pain, breathlessness and current smoking. Self-assessment of health status appears to be a good measure of current physical health and risk of death. It could be useful in both clinical and epidemiological situations.

Adult↗
PubMed1991

Early life experience and adult cardiovascular disease: longitudinal and case-control studies.

It has been postulated that experiences early in life influence cardiovascular risk in later adult life. This article considers 15 longitudinal and four case-control studies which, directly or indirectly, have examined the hypothesis concerning the prenatal and childhood origins of adult cardiovascular disease. Criteria laid down by Bradford Hill were used to assess whether these epidemiological studies provided sufficient evidence for a causal relation between experiences early in life and subsequent cardiovascular risk. No consistent dose-response relationship was found between the index of early life experience and adult cardiovascular disease. The relationships were usually non-specific with the index of early life experience being correlated with several causes of death, not only cardiovascular disease. The formulation of the hypothesis varied between the studies. Most reports dealt inadequately with the fact that the relation between adult cardiovascular risk and early life experience was confounded by persisting social and economic disadvantage. Overall these studies do not provide strong support for the hypothesis that experiences early in life determine the subsequent risk of cardiovascular disease. While future epidemiological studies may resolve this issue, the very nature of the hypothesis presents methodological problems that may prove to be insurmountable. Further progress in this field urgently requires the formulation of a clear and specific hypothesis.

Adult↗
PubMed1991

The contribution of environmental temperature and humidity to geographic variations in blood pressure.

The pattern of geographic blood pressure variations in Britain has raised the possibility that temperature or other climatic factors may be of importance. Data from two population studies have been examined: the British Regional Heart Study (BRHS), which involved 7735 mean aged 40-59 years, and the Nine Towns Study (NTS), concerning blood pressure among 2596 men and women aged 25-59 years. In the BRHS, significant negative associations were found between daily maximum outdoor temperature and systolic blood pressure (-0.38 mmHg/degrees C; P less than 0.001) and diastolic blood pressure (-0.18 mmHg/degrees C; P less than 0.001). There were similar, although non-significant, associations in the NTS. No significant associations were found between blood pressure and room temperature in either study after taking account of town blood pressure differences, nor between blood pressure and outdoor humidity in the NTS. In the NTS, skin temperature was negatively associated with blood pressure after the adjustment for body mass index, significantly so for male diastolic (-0.62 mmHg/degrees C; P less than 0.05). The BRHS estimates suggest that, in Britain, geographic differences in outdoor temperature may contribute no more than 2 mmHg systolic and 1 mmHg diastolic to regional blood pressure variations. This represents a relatively small proportion of the town differences in blood pressure observed in both the BRHS and NTS. Furthermore, international comparisons suggest that environmental temperature is not an important determinant of population blood pressure levels.

Adult↗
PubMed1991

Place of birth and adult cardiovascular disease: the British Regional Heart Study.

Coronary heart disease (CHD) is almost certainly a nutritional disorder related to the quality and quantity of dietary fats and mediated by blood and tissue lipid concentrations. There is current controversy as to when the underlying process of atherosclerosis is initiated and whether the critical susceptibility to CHD may be established in utero or infancy. Blood pressure and hypertension may also be nutritionally based, and the age at which the rate of rise in blood pressure with age is determined is also controversial. The British Regional Heart Study (BRHS) involves 7,735 middle-aged men from 24 towns in England, Wales and Scotland and reveals that average blood cholesterol levels in these towns show no relationship to CHD mortality but all are high by international standards. Blood pressure levels vary markedly between the 24 towns and relate strongly to CHD mortality patterns, which are highest in Scotland and lowest in the South of England. The hypothesis relating adult blood pressures and CHD mortality to foetal and infant life circumstances has been examined using the data on birthplace and place of examination of the BRHS men. Regardless of where they were born, men living and examined in the South had lower mean blood pressures than men living in Scotland. The highest mean blood pressures were observed in Scotland, irrespective of where the men had been born. For CHD, regardless of their place of birth, men living in the South had a lower risk of CHD than men living elsewhere. The geographic zone of examination appeared to be more important than the zone of birth in determining the risk of CHD and the level of blood pressure. While patterns of nutrition during pregnancy, in infancy and childhood may be of importance for some outcomes, such as height, it seems that exposure to risk factors during adult life predominantly determine the outcome in cardiovascular disease.

Adult↗
PubMed1991

Physical activity and ischaemic heart disease in middle-aged British men.

OBJECTIVE: To assess the relation between reported physical activity and the risk of heart attacks in middle aged British men. DESIGN: Prospective study of middle-aged men followed for a period of eight years (The British Regional Heart Study). SETTING: One general practice in each of 24 British towns. PARTICIPANTS: 7735 men aged 40-59 years at initial examination. END POINT: Heart attacks (non-fatal and fatal). MEASUREMENTS AND MAIN RESULTS: During the follow up period of eight years 488 men suffered at least one major heart attack. A physical activity score used was developed and validated against heart rate and lung function (FEV1) in men without evidence of ischaemic heart disease. Risk of heart attack decreased significantly with increasing physical activity; the groups reporting moderate and moderately vigorous activity experienced less than half the rate seen in inactive men. The benefits of physical activity were seen most consistently in men without preexisting ischaemic heart disease and up to levels of moderately vigorous activity. Vigorously active men had higher rates of heart attack than men with moderate or moderately vigorous activity. The relation between physical activity and the risk of heart attack seemed to be independent of other cardiovascular risk factors. Men with symptomatic ischaemic heart disease showed a reduction in the rate of heart attack at light or moderate levels of physical activity, beyond which the risk of heart attack increased. Men with asymptomatic ischaemic heart disease showed an increasing risk of heart attack with increasing levels of physical activity, but with a progressive decrease in case fatality. Overall, men who engaged in vigorous (sporting) activity of any frequency had significantly lower rates of heart attack than men who reported no sporting activity. However, when all men reporting regular sporting activity at least once a month were excluded from analysis, there remained a strong inverse relation between physical activity and the risk of heart attack in men without pre-existing ischaemic heart disease. CONCLUSION: This study suggests that the overall level of physical activity is an important independent protective factor in ischaemic heart disease and that vigorous (sporting) exercise, although beneficial in its own right, is not essential in order to obtain such an effect.

Adult↗
PubMed1991

Alcohol intake and variations in blood pressure by day of examination.

The patterns of drinking and variations in blood pressure and gamma-glutamyl transferase (GGT) by day of examination have been examined in a large prospective study of cardiovascular disease in 7,735 middle-aged men drawn from general practices in 24 British towns. Overall, mean systolic and diastolic BP levels, as well as the prevalence of measured hypertension, were significantly higher on Mondays and lower on Fridays than on other weekdays. Among occasional, moderate weekend (3-6) and heavy weekend (greater than 6 drinks/day) drinkers, although mean BPs were higher in the heavier drinkers, there was little variation in BP from Monday to Thursday in these groups. In all three groups there was a significant fall in mean BP and in the prevalence of hypertension on Friday, more apparent for systolic than for diastolic pressure and more marked in older men. Among daily drinkers, BP tended to be high on Mondays but was not particularly low on Fridays. Heavy weekend drinkers had higher daily BPs than moderate daily drinkers except on a Friday, even though the estimated total weekly intake was similar. The variations in BP by day of examination were not mirrored by changes in GGT concentrations. The different effect of daily and weekend patterns of drinking on BP may explain some of the discrepancies observed between different alcohol-blood pressure studies. Findings from this study have important implications for the detection of hypertension in populations as well as for clinical practice.

Adult↗
PubMed1991

Serum calcium and blood pressure.

The association between serum calcium and blood pressure was examined in a sample of 7,735 healthy middle-aged British men (The British Regional Heart Study). There was a small but significant correlation between serum calcium and both systolic and diastolic blood pressure (r = 0.15 and 0.11, respectively; P less than 0.0001) after adjusting for age. This association was diminished after adjustment for serum albumin, but remained significant (r = 0.10 and 0.07; P less than 0.0001). This finding is consistent with results from previous studies. To assess whether the association between serum calcium and blood pressure is independent of the levels of other blood constituents, 20 biochemical and haematological factors were examined to identify possible confounding factors. The association between calcium and blood pressure disappeared after adjustment for serum globulins and haematocrit in addition to age and serum albumin. Thus, these factors appear to mediate the weak association between serum calcium and both systolic and diastolic blood pressure. There does not appear to be an independent relationship between serum calcium and blood pressure.

Adult↗
PubMed1990

Consultation rates among middle aged men in general practice over three years.

OBJECTIVE: To provide data on consultation rates in general practice for middle aged men over three years according to their age and social class. DESIGN: Prospective study of men over eight years. Data on consultation rates during years 6-8 were collected retrospectively from practice records. SETTING: Over 1000 general practices in Great Britain by year 8. Initially (in 1978-80) the men had been selected at random from one practice in each of 24 towns. SUBJECTS: 7013 Men aged 46-65 in the sixth year of follow up. MAIN OUTCOME MEASURE: Number of consultations a year over three years. RESULTS: The mean annual consultation rate over the three years rose steadily with age (7.0 at age 46-50 to 9.7 at age 61-65) and with social class (6.4 in class I to 10.0 in class V) but was potentially misleading as the distribution was skew: 10.5% of men (736) did not consult over the three years and 17.2% (1209) consulted only once or twice, whereas 11.4% (798) of men were seen more than 18 times. The percentage of men who did not consult over three years fell only slightly with age and was unrelated to social class, with roughly a tenth of all age and social class groups not consulting. Two thirds of non-consulters in year 6 (1598/2334) consulted in year 7 or 8. CONCLUSIONS: The mean is not an appropriate summary measure of consultation rates and may conceal important differences among practices or other groups. The new general practitioner contract stipulates that all patients aged 16-74 must be provided with information to promote health and prevent illness at least once every three years. Most practices will have to approach a tenth of their men aged 46-65 specially to provide this service even if one consultation in three years is regarded as sufficient to allow a service to be provided.

Age Factors↗
PubMed1990

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.

ABO Blood-Group System↗
PubMed1990

Migration and geographic variations in blood pressure in Britain.

OBJECTIVE: To evaluate the relative contributions of factors acting at different stages in life to regional differences in adult blood pressure. DESIGN: Prospective cohort study (British regional heart study). SETTING: One general practice in each of 24 towns in Britain. SUBJECTS: 7735 Men aged 40-59 years when screened in 1978-80 whose geographic zone of birth and zone of examination were classified as south of England, midlands and Wales, north of England, and Scotland. Non-migrants (n = 3144) were born in the town where they were examined; internal migrants (n = 4147) were born in Great Britain but not in the town where they were examined; and international migrants (n = 422) were born outside Great Britain. MAIN OUTCOME MEASURES: Systolic and diastolic blood pressures and height. RESULTS: Regardless of where they were born, men living in the south of England had lower mean blood pressures than men living in Scotland (142.5/80.1 v 148.1/85.2 mm Hg). The effects of the place of birth and place of examination on adult blood pressure were examined in a multiple regression model. For internal migrants the modelled increase in mean systolic blood pressure across adjacent zones of examination was 2.1 mm Hg (95% confidence interval 1.3 to 2.9); for adjacent zones of birth the corresponding increase was 0.1 mm Hg (-0.7 to 0.7). The place of examination seemed to be a far more important determinant of mean adult blood pressure than the place of birth. Height is an accepted marker of genetic and early life influences. Regional differences in height were therefore analysed to test whether the multiple regression model could correctly distinguish between the influence of place of birth and place of examination. As expected, men born in Scotland were shorter on average than men born in the south of England irrespective of where they lived in Britain (172.6 cm v 175.1 cm for internal migrants). CONCLUSION: Regional variations in blood pressure were strongly influenced by where the men had lived for most of their adult lives rather than by where they were born and brought up. Among middle aged men, factors acting in adult life seemed to be more important determinants of regional differences in blood pressure than those acting early in life such as genetic inheritance, intrauterine environment, and childhood experience.

Adult↗
PubMed1990

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.

Adult↗