W.C.S. Smith

Plasma fibrinogen and coronary risk factors: The Scottish heart health study

Plasma fibrinogen was measured in a sample of 8824 men and women aged 40-59 years participating in the Scottish Heart Health Study, and related to cardiovascular risk factors. Women had higher fibrinogen levels than men. In both sexes, multivariate analysis showed that fibrinogen was positively associated with age, smoking, total cholesterol and body mass index and negatively associated with alcohol consumption. Among women, early menopause and systolic blood pressure were also associated with fibrinogen levels. Univariate analyses showed weak positive associations with fish consumption for both sexes although only male white fish consumption entered the final model. Women with a history of contraceptive pill usage had significantly lower fibrinogen levels. The relationship between fibrinogen and physical activity was complex, and could largely be explained by smoking. These findings support the hypothesis that raised fibrinogen is one mechanism by which several major risk factors may promote coronary heart disease. However, known risk factors explained, at most, 10% of the total variance in fibrinogen levels among the general population.

Antioxidant vitamin intakes assessed using a food-frequency questionnaire: correlation with biochemical status in smokers and non-smokers

The increasing interest in the possible role of antioxidant vitamins in many disease states means that methods of assessing vitamin intakes which are suitable for large-scale investigations are now required. The suitability of the food-frequency questionnaire, which was developed by the Medical Research Council - Cardiff Group, for determining dietary intake of antioxidant vitamins in epidemiological studies was investigated in 196 Scottish men. The validity of the dietary data was assessed by comparison with serum vitamin concentrations, and separate analyses were performed for current smokers and non-smokers. The results showed that total energy intake and the percentage of energy derived from sugar were higher in smokers, and that both dietary and serum values of vitamin C, beta-carotene and vitamin E were lower in smokers than non-smokers. After adjustment for serum lipids, energy intake and body mass index, correlation coefficients between dietary and serum vitamins C and E were similar for smokers (r 0.555 and 0.25 respectively) and non-smokers (r 0.58 and 0.32 respectively). Correlation between dietary and serum carotenes was reduced from 0.28 in non-smokers to 0.09 in smokers and correlations for retinol and total vitamin A were weakly significant only for non-smokers. The food-frequency questionnaire assigned greater than 70% of subjects correctly into the upper or lower plus adjacent tertiles of serum vitamin values, with the exception of beta-carotene and total vitamin A for smokers. Thus, the food-frequency questionnaire appeared to be an adequate tool for assigning individuals into tertiles of serum antioxidant vitamins with the main exception of beta-carotene for smokers. Marked differences do occur between the vitamins and between the smoking groups which may reflect reduced accuracy of reporting on the food-frequency questionnaire or differential absorption and metabolism of the vitamins.

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

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

Nutrient intakes of different social-class groups : results from the Scottish Heart Health Study (SHHS)

Food frequency questionnaire and socio-demographic data were collected from over 10,000 Scottish men and women aged 40-59 years in a cross-sectional study of coronary heart disease (CHD) risk factors. Dietary intake, including the antioxidant vitamins C and E and beta-carotene, was assessed for different socio-economic groups. Trends in nutrient intakes were found with social-class (occupational) groups I-V. The non-manual-manual distinctions were clear even after standardizing for serum cotinine, and alternative classification by housing tenure and level of education did not confound the social-class effect. Total energy intake was significantly higher in the manual (men 10,363 KJ, women 7507 KJ) than in the non-manual (men 9156 KJ, women 7169 KJ) groups, and all nutrient amounts except for vitamin C, vitamin E, beta-carotene and fibre were significantly higher in the manual than the non-manual groups. Alcohol intake was lower in manual women, but higher in manual men compared with their respective non-manual groups. Sex and social-class differences were maintained after adjusting for total energy. Women in general, and manual women in particular, had the highest percentage energy from total fat (40.2) and saturated fat (18.2), while the percentage energy from polyunsaturated fat was lower in men than women, and lowest in manual men (4.4). The polyunsaturated:saturated fat (P:S) ratios were, for non-manual and manual men 0.32 and 0.31, and for non-manual and manual women 0.31 and 0.28. Fibre and antioxidant vitamin intakes, when expressed as nutrient densities, were lower in men than women, and lowest in manual men. Overall, men and women in manual occupations had a poorer-quality diet than did those in non-manual occupations. The coincident low P:S ratios and low antioxidant vitamin intakes in manual groups may contribute to an increased risk of CHD. Thus, the findings are compatible with the view that poor diet may be a contributory factor to the higher mortality rates for CHD which occur in the lower socio-economic groups.

Urinary electrolyte excretion, alcohol consumption, and blood pressure in the Scottish heart health study

As part of a study of risk factors for coronary heart disease 24 hour urine collections were obtained from 7354 men and women aged 40-59 selected at random from 22 districts throughout Scotland (Scottish heart health study). The mean of two standardised measurements of blood pressure was related to the reported consumption of alcohol and measurements of height, weight, pulse rate, and electrolyte excretion. Several significant correlations were found with both systolic and diastolic pressure, but only the coefficients for age, body mass index, and pulse rate were greater than 0.1. Alcohol consumption showed a weak positive correlation with blood pressure in men. Sodium excretion showed a weak positive correlation with blood pressure in both sexes, and potassium excretion showed weak negative correlations. In multiple regression analysis age, pulse rate, body mass index, alcohol consumption, and potassium excretion had significant independent effects but sodium excretion did not. Although measuring blood pressure twice on one occasion and 24 hour urinary sodium excretion only once may have weakened any potential correlation, the most likely explantation of these results is that the relation between sodium and blood pressure in the population is weak and that potassium and alcohol are of greater importance.

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 1.0mmol/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.

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. Many participants did not eat fresh fruit or green vegetables. High cholesterol and cigarette smoking levels provide a classical explanation for the excess of coronary deaths in Scotland, justifying action, but other factors, such as the dietary deficiencies, also merit further investigation.

Smoking characteristics and inhalation biochemistry in the Scottish population

Data from a cross-sectional random population sample of 10,359 middle-aged Scottish men and women are used to investigate the relationships between self-reported tobacco consumption and three biochemical markers of tobacco inhalation: expired air carbon monoxide (CO), serum thiocyanate and serum cotinine. These data represent one of the largest samples of these biochemical markers yet analysed. The results show that, for each sex, the biochemical markers are highly correlated for smokers and for the entire sample of mixed smokers and non-smokers. CO is the preferred biochemical marker, in such groups, because it is the cheapest, is non-invasive and gives virtually instantaneous results. Self-reported daily cigarette consumption also correlates well with each of these biochemical markers, and so it appears that people are, in the context of population studies, mainly truthful about their smoking. The relationships with self-reported cigarette consumption are curvilinear with apparent levelling out of the gradient at around 25 cigarettes/day for cotinine and thiocyanate and at greater than 40 cigarettes/day for CO. Sex differences are small, although thiocyanate is generally higher and cotinine generally lower in women with the same self-reported cigarette consumption as men. Amongst non-smokers, only cotinine is able to discriminate between self-reported levels of exposure to passive smoking. CO and thiocyanate are not suitable for measuring low levels of smoke inhalation, such as found in passive smokers.

Plasma fibrinogen in women: relationships with oral contraception, the menopause and hormone replacement therapy

Summary. Plasma fibrinogen was measured in 4837 women aged 25‐64 years as part of the Scottish Heart Health Study and Scottish MONICA population surveys. The relationships of oral contraceptive use, the menopause and hormone replacement therapy were examined.

Prevalence of coronary heart disease in Scotland: Scottish Heart Health Study.

Data from 10,359 men and women aged 40-59 years from 22 districts in the Scottish Heart Health Study were used to describe the prevalence rates of coronary heart disease in Scotland in 1984-1986 and their relation to the geographical variation in mortality in these districts. Prevalence was measured by previous history, Rose chest pain questionnaire, and the Minnesota code of a 12 lead resting electrocardiogram. The prevalence of coronary heart disease in Scotland was high compared with studies from other countries that used the same standardised methods. A history of angina was more common in men (5.5%) than in women (3.9%), though in response to the Rose questionnaire 8.5% of women and 6.3% of men reported chest pain. A history of myocardial infarction was three times more common in men than women, as was a Q/QS pattern on the electrocardiogram. There were significant correlations between the different measures of coronary prevalence. District measures of angina correlated well with mortality from coronary heart disease, and these correlations tended to be stronger in women than in men. There was no significant correlation between mortality from coronary heart disease and measures of myocardial infarction. The study provides data on the prevalence of coronary heart disease in men and women that are valuable for the planning of cardiological services.