Emanuela Falaschetti, Anne McMunn, Paola Primatesta, Marion Brookes
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SUMMARY
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Coronary heart disease (CHD) continues to be a leading cause of morbidity and mortality among adults in Europe and North America.1 Scotland has the highest mortality rate from CHD for men and the second highest for women compared with the other industrial countries. The White Paper: 'Towards a healthier Scotland' recognises that reducing the rate of premature deaths and illness from coronary heart disease remains a huge challenge for Scotland. The Government's headline target is to reduce the age-standardised mortality rate from coronary heart disease in people under age 75 by 50% between 1995 and 2010.2 The two most common causes of death in Scotland are coronary heart disease and cancer. The British Cardiac Society et al. and the Scottish Intercollegiate Guidelines Network (SIGN) have recently published new recommendations on the clinical management of CVD.3,4,5
This chapter reports the prevalence of self-reported CVD conditions for the Scotland adult population (aged 16-74), examines CVD differences between regions and social classes, trends over time and comparisons with England. Findings on four blood analytes (total cholesterol, HDL-cholesterol, fibrinogen and C-reactive protein) associated with risk for cardiovascular disease are also presented and compared over time and with England. Furthermore the prevalence of cardiovascular disease is presented in association with a variety of risk factors.
2.2.1 Methods
Informants were asked whether they suffered from any of the following conditions: angina, heart attack, stroke, intermittent claudication, heart murmur, abnormal heart rhythm, 'other heart trouble', diabetes and high blood pressure, and (if they responded affirmatively) they were asked if they had ever been told by a doctor they had the condition. For the purpose of this report, informants were classified as having a particular condition only if they reported that the diagnosis was confirmed by a doctor (or by a nurse in the case of blood pressure). Those informants who reported having a particular condition were also asked if they had it in the last 12 months (referred to in the Tables as 'currently'), with the exception of high blood pressure (where they were asked if they still had it and if they were taking medication for it) and diabetes (where it was assumed that the condition is chronic and irreversible).
It should be noted that high blood pressure and diabetes are generally considered to be predisposing factors rather than cardiovascular conditions per se and they have been included in this chapter for comparability with previous surveys (see Chapter 12 for analysis of blood pressure measurements). Women were not classified as having hypertension (high blood pressure), diabetes or a heart murmur, if they had the condition when pregnant only.
2.2.2 Summary measures of cardiovascular disease
On the basis of self-reported cardiovascular conditions, the following summary measures were used.
2.2.3 Rose angina and possible myocardial infarction
In addition to the self-reported prevalence of angina and heart attack, the Rose questionnaire on angina and heart attack ('Rose Angina Questionnaire') was used as an alternative means of estimating the prevalence of these conditions. The Rose Angina Questionnaire was originally developed to identify the characteristic symptom complex known as angina in a standard way.6 From this questionnaire, informants were classified as having angina symptoms based on standard criteria.7 Angina was then classified as grade 1 or grade 2, with grade 2 being the most severe.
Also from the Rose Angina questionnaire, informants were classified as having had a possible myocardial infarction (heart attack) if they reported having ever had an attack of severe pain across the front of the chest, lasting for half an hour or more (but not necessarily confirmed as heart attack by a doctor).
2.2.4 Intermittent claudication
Intermittent claudication is the most common symptom of peripheral vascular disease and is defined as a pain, ache, cramp, numbness, or sense of fatigue in the muscles; it occurs during exercise and is relieved by rest. It has been shown to be independently related to mortality from cardiovascular disease and possibly non-cardiovascular disease.8 The prevalence of intermittent claudication can only be accurately assessed in a population survey, as only a small proportion of patients with this condition requires hospital referral. Standard questions, based on the Edinburgh Questionnaire,9 were used and informants were classified as having the condition if they reported leg pain on walking, but not at rest, which disappeared within 10 minutes after they stopped walking. Intermittent claudication was further classified as grade 1 or grade 2, with grade 2 being more severe.10
2.2.5 Interpretations
It should be stressed that the data presented in this section should be interpreted with caution, since they are based on self-reported diagnosis or symptoms. No attempt was made to assess these self-reported diagnoses objectively. There is therefore the possibility that some misclassification may have occurred, because some informants may not have remembered (or not remembered correctly) the diagnosis made by their doctor.
2.3.1 Prevalence of cardiovascular conditions
Angina
Overall, 5.0% of men and 4.2% of women reported having ever had angina and 3.5% of men and 3.1% of women reported having had it in the past twelve months. In both sexes the prevalence increased with age, particularly after age 55, being less than 1% in those aged under 45 and 20.6% in men and 15.4% in women aged 65-74.
Heart attack
Reports of having ever had a heart attack were twice as high among men (3.8%) than among women (1.7%). In both sexes the prevalence increased with age, ranging among men from 0.1% in those aged 25-34 to 16.8% in those aged 65-74, and among women from 0.2% in those aged 35-44 to 7.4% in those aged 65-74.
Overall only 0.5% of men and 0.3% of women reported having had a heart attack in the past twelve months; among men aged 55-64 this percentage was 1.8% (almost 20% of those in this age group who reported having ever had a heart attack).
Stroke
Very few informants reported having ever had a stroke at 1.3% of men and 1.2% of women. Those who had had a stroke were concentrated mainly in the oldest age group (65-74) in which the prevalence was 6.4% for men and 5.5% for women.
Overall 0.3% of men and 0.2% of women reported having had a stroke in the previous 12 months.
Hypertension
Hypertension (high blood pressure) was the most frequent of the conditions and was reported by 16.5% of both men and women. Among men the rate increased with age from 2.5% in those aged 16-24 to 39.7% in those aged 65-74 and from 3.6% to 36.4% among women.
Overall, 9.8% of men and 10.7% of women reported currently having high blood pressure and the increase with age was more marked than in informants who reported having ever had high blood pressure.
Diabetes
Overall, 2.8% of men and 2.0% of women reported being diabetic. The prevalence increased with age in both sexes and was higher among men than women in each age group. Among the older age groups the rates were 5.5% in men aged 55-64 and 8.3% in those aged 65-74; the corresponding figures in women were 4.7% and 5.8%.
Heart murmur, abnormal heart rhythm and 'other' heart trouble
Reporting of having ever had heart murmur was slightly higher in women (3.0%) than in men (2.3%). The difference between younger and older age groups was less marked than in the other conditions. Among men the rate increased from 1.1% in those aged 16-24 to 3.5% in those aged 65-74 and among women from 1.7% to 4.5%.
Overall, 3.5% of men and 4.2% of women reported having ever had abnormal heart rhythm and the prevalence increased with age in both sexes.
When an informant reported a heart condition that could not be placed in any of the above-mentioned categories they were considered as having had 'other heart trouble' which was the case for 1.6% of men and 0.8% of women.
2.3.2 Summary measures
Any cardiovascular disorder
The prevalence of any cardiovascular disorder was similar in men and women (23.6% and 23.5%) and increased with age in both sexes. Among men it ranged from 4.4% in those aged 16-24 to 57.9% in those aged 65-74 and among women it ranged from 6.4% to 50.7%. A large proportion of this prevalence was due to informants who reported having ever had a diagnosis of hypertension. In fact almost 50% of both men and women who reported having had any cardiovascular disorder only had high blood pressure (data not shown).
Ischaemic heart disease (IHD)
The prevalence of ischaemic heart disease was 6.4% in men and 4.6% in women overall but increased steeply with age. It was negligible up to age 44, then was almost three times higher among those aged 55-64 (16.1% in men, 10.7% in women) than among those aged 45-54 (6.6% in men, 3.8% in women) and continued increasing to 27.3% in men and 17.3% in women aged 65-74.
Ischaemic heart disease or stroke
Combining ischaemic heart disease and stroke, the prevalence became 7.2% in men and 5.3% in women. The pattern with age was similar to that for ischaemic heart disease alone, with the prevalence only substantial after age 55. Among those aged 55-64 the prevalence of IHD or stroke was 17.1% in men and 11.9% in women; among those aged 65-74 it was 31.0% in men and 20.9% in women. Prevalence was very low among young adults, being less than 1% up to age 44.
2.3.3 Prevalence of angina and possible myocardial infarction (MI), using the Rose Angina Questionnaire
Angina
The overall prevalence of ever having angina, combining grade 1 and grade 2, using the Rose Angina Questionnaire was 3.5% for men and 3.1% for women. It was higher in men than in women in older age groups. The prevalence of angina symptoms as assessed by the Rose Questionnaire was lower than for reported doctor-diagnosed angina in older age groups and higher in younger age groups (Table 2.1). This dissimilarity between the Rose Angina Questionnaire and self-reported doctor-diagnosed angina was also seen in the 1993 and 1994 Health Surveys for England.11,12
Myocardial infarction
Overall, 6.9% of men and 4.2% of women had symptoms of possible myocardial infarction according to the Rose Questionnaire. The prevalence increased with age in both sexes and was higher among men than among women in all age groups. The overall prevalence was higher than the reported doctor-diagnosed heart attack rates (3.8% in men and 1.7% in women) but the differences between men and women and between younger and older age groups were less marked than in the doctor-diagnosed reports.
Table 2.4
2.3.4 Intermittent claudication
The prevalence of intermittent claudication tended to increase with age and to be higher in men than in women. The overall rate was 2.1% in men and 1.8% in women. The rates among those aged 65-74 were 6.9% for men and 4.4% for women. Prevalence of intermittent claudication was also analysed by the presence of any cardiovascular disorder and by IHD or stroke. Intermittent claudication was more frequent among those who had ever had any cardiovascular disorder than among those who had not (5.5% compared with 1.0% in men and 4.3% compared with 1.0% in women). The difference was even more marked looking at IHD or stroke: in fact prevalence of intermittent claudication was 9.8% in men and 7.8% in women among those who had ever had IHD or stroke compared with 1.5% among those (men and women) who had not.
2.4 REGIONAL VARIATIONS IN THE PREVALENCE OF CARDIOVASCULAR DISEASE
2.4.1 Any cardiovascular disorder by region
The age-standardised prevalence of any cardiovascular disorder did not reveal any significant regional variation. Among men it ranged from 20.2% in Grampian & Tayside to 26.6% in Lanarkshire, Ayrshire & Arran. Among women it ranged from 22.0% in Lothian & Fife to 25.7% in Greater Glasgow.
2.4.2 Ischaemic heart disease or stroke by region
There was no significant regional variation in ischaemic heart disease or stroke. Among men the age-standardised prevalence of ischeamic heart disease or stroke ranged from 6.3% in Grampian & Tayside and Forth Valley, Argyll & Clyde to 9.2% in Borders, Dumfries & Galloway. Among women it ranged from 2.9% in Highland & Islands to 6.2% in Greater Glasgow.
2.5 SOCIAL CLASS VARIATIONS IN THE PREVALENCE OF CARDIOVASCULAR DISEASE
2.5.1 Any cardiovascular disorder by social class
The age-standardised prevalence of any cardiovascular disorder was highest in Social Class V (30.4% in men and 28.8% in women) and lowest in Social Class I (18.2% in men and 14.0% in women). A clear gradient was seen among women whose rate increased consistently from Social Class I to V. This pattern was not present among men where the prevalence was lowest in Social Class I and highest in Social Class V while other classes (II to IV) showed similar prevalence rates.
2.5.2 Ischaemic heart disease or stroke by social class
There was a significant social class gradient in the prevalence of ischaemic heart disease or stroke in women but not in men. Among men the age-standardised prevalence was significantly lower in Social Classes I and II (4.1% and 5.9% respectively) than in the other social classes (7.9% to 9.2%). Among women it was lowest in Social Class I (1.3%), fluctuated around 5% in Social Classes II, IIINM and IIIM and then increased to around 8% in Social Classes IV and V.
2.6 TRENDS OVER TIME IN THE PREVALENCE OF CARDIOVASCULAR DISEASE
2.6.1 Any cardiovascular disorder by survey year
Overall, the prevalence of any cardiovascular disorder among men remained effectively the same between 1995 (19.3%) and 1998 (19.5%). Among women it decreased slightly from 20.2% to 19.5%. Women showed a decrease in prevalence of any cardiovascular disorder in each age group except the oldest (55-64) where the rate increased from 40.6% in 1995 to 44.8% in 1998; however none of these differences was statistically significant.
2.6.2 Ischaemic heart disease or stroke by survey year
There was no difference in the prevalence of ischaemic heart disease or stroke between the two survey years. Among men it was 4.6% in 1995 and 4.4% in 1998. The corresponding figures for women were 3.2% and 3.0%.
2.6.3 Rose angina symptoms and possible myocardial infarction by survey year
There were no significant differences in the prevalence of angina as assessed by the Rose Questionnaire between 1995 and 1998. The prevalence was 2.8% in 1995 and 2.9% in 1998 among men and 2.7% among women in both 1995 and 1998.
The prevalence of possible myocardial infarction (MI) as assessed by the Rose Questionnaire increased slightly between 1995 and 1998 in all age groups in both men and women. Overall the prevalence of MI increased from 3.4% in 1995 to 6.0% in 1998 among men and from 2.5% to 3.7% among women.
Figure 2A Prevalence of any Cardiovascular disorder (including high blood pressure), Ischaemic heart disease (heart attack or angina) or Stroke, by social class of chief income earner and sex
2.6.4 Any cardiovascular disorder and ischaemic heart disease or stroke by region and survey year
After adjusting for age using logistic regression, there were no significant regional differences in the prevalence of any cardiovascular disorder between 1995 and 1998 in men or women. Among men the prevalence of any cardiovascular disorder increased by almost 3 percentage points in Lanarkshire, Ayrshire & Arran while in Forth Valley, Argyll & Clyde it decreased by 5 percentage points. In this region the 1998 prevalence (18.9%) was close to the national average while in 1995 (23.9%) it was above average with the highest regional rate. Among women the prevalence of any cardiovascular disorder did not vary except in Lanarkshire, Ayrshire & Arran where it decreased from 24.9% in 1995 to 20.3% in 1998.
Changes between 1995 and 1998 in the prevalence of ischaemic heart disease or stroke were non-significant in all regions.
2.6.5 Any cardiovascular disorder and ischaemic heart disease or stroke by social class by survey year
Social class variation in the prevalence of any cardiovascular disorder changed significantly from 1995 to 1998 for both men and women. Among men Social Classes IIINM and V presented the biggest age-standardised increases: from 16.2% to 21.3% and from 20.6% to 27.3% respectively. On the other hand the prevalence decreased from 21.9% to 18.7% in Social Class IIIM. Among women between 1995 and 1998 the prevalence of any cardiovascular disorder decreased from 22.2% to 11.8% in Social Class I and increased from 22.3% to 25.7% in Social Class V.
There were small (non-significant) variations between 1995 and 1998 in the prevalence of ischaemic heart disease or stroke in every social class.
2.7.1 Success rates in obtaining blood samples
This section presents findings on the blood analytes: total cholesterol, HDL-cholesterol, fibrinogen and C-reactive protein, which are all independently associated with cardiovascular disease.
Of the 9,047 informants interviewed, 7,455 were also visited by a nurse. A blood sample was obtained from 84.4% of men and 80.1% of women who had a nurse visit. The lower proportion for women was mainly because pregnant women were ineligible. The rest of the informants either refused or the nurse was unable to successfully obtain a blood sample. Among men who had a nurse visit the proportions for whom valid measurements were obtained were: 81.7% for total cholesterol, 81.2% for HDL-cholesterol, 82.8% for C-reactive protein and 75.4% for fibrinogen. The corresponding figures among women were: 77.7% for total cholesterol, 77.3% for HDL-cholesterol, 78.4% for C-reactive protein and 71.5% for fibrinogen. Those aged 65-74 were less likely than younger age groups to have valid measurements.
2.7.2 Total cholesterol
Prospective studies have identified an increased risk of coronary disease associated with raised cholesterol concentration. The West of Scotland Coronary Prevention Study (WOSCOPS) found that cholesterol-lowering drug therapy significantly reduced the incidence of myocardial infarction and death from cardiovascular causes without adversely affecting the risk of death from noncardiovascular causes in men with moderate hypercholesterolaemia and no history of myocardial infarction.13,14 A meta-analysis of all randomised trials of more than two years duration showed that lowering serum cholesterol confers clinical benefit as expressed in lower CHD mortality and total mortality risk, with the magnitude of benefit directly related to the degree of cholesterol reduction.15 For the purpose of this survey cholesterol was considered to be raised at a level of 6.5 mmol/l or over as in the 1995 Health Survey.
By age and sex
Mean total cholesterol was the same (5.4 mmol/l) in men and women. In men it increased with age from 4.3 mmol/l in those aged 16-24 to 5.9 mmol/l in those aged 45-54, then slightly decreased in the older age groups. In women it increased continuously with age from 4.5 mmol/l in those aged 16-24 to 6.4 mmol/l in those aged 65-74. Total cholesterol was higher in women than in men from age 55 onwards.
Overall 16.9% of men and 18.1% of women had a cholesterol level of 6.5 mmol/l or above. Among men the prevalence of raised cholesterol increased up to age 54 with a jump from 6.7% among those aged 25-34 to 22.0% among those aged 35-44, then decreased from age 55 onwards. Among women the prevalence of raised cholesterol increased continuously with age with a jump from 7.0% among those aged 35-44 to 23.5% among those aged 45-54. The prevalence of raised cholesterol was higher in men than in women in central age groups, especially in those aged 35-44 (22.0% in men compared with 7.0% in women). In contrast, it was higher in women in the older age groups (23.9% in men compared with 38.6% in women aged 55-64 and 18.1% in men compared with 43.3% in women aged 65-74). This is consistent with the reported increase in cholesterol after the menopause.
Figure 2B Prevalence of raised total cholesterol (6.5 mmol/l or above) by survey year, age and sex
By survey year
As already noted, the laboratory used in 1998 was different from that used in 1995. Although they both used the same method, some caution is necessary when interpreting these results. Mean total cholesterol in 1998 was slightly lower than in 1995 in both men and women. In the age range 16-64 (considered in the comparison), mean total cholesterol decreased from 5.6 mmol/l to 5.4 mmol/l in men and from 5.6 mmol/l to 5.3 mmol/l in women. The decreases were consistent across all age groups.
There was a decrease from 1995 to 1998 in the proportion of informants with raised cholesterol in both men and women for all age groups. Overall this proportion decreased from 22.5% to 16.7% among men and from 21.3% to 14.7% among women.
2.7.3 HDL-cholesterol
Studies have shown that high-density lipoprotein cholesterol (HDL-cholesterol) is inversely and independently associated with the risk of developing CHD.16,17 Furthermore, low levels of HDL-cholesterol are associated with a worse prognosis after myocardial infarction.18 Protection against CVD by HDL-cholesterol is conferred in at least two ways. The first is that it transports cholesterol back from organs such as arteries to the liver for elimination, thus protecting the arteries from further atheromatous plaque formation. The second is by acting as an antioxidant. Increasing physical activity, decreasing alcohol intake, quitting cigarette smoking and losing weight can elevate HDL-cholesterol. Attention is generally recommended for HDL-cholesterol concentrations <1 mmol/l.
By age and sex
Mean HDL-cholesterol was higher in women (1.6 mmol/l) than in men (1.3 mmol/l). There were no differences in mean HDL-cholesterol level by age groups for men or women.
The proportion of informants with a HDL-cholesterol level less than 1 mmol/l was almost three times higher in men (16.0%) than in women (5.5%). No clear pattern was observed by age: informants aged 55-64 had the highest rate of low HDL-cholesterol in both men (20.6%) and women (8.1%).
By survey year
It should be noted that the laboratory used in 1998 was different from that used in 1995. Although they both used the same method, some caution is necessary when interpreting these results.
Mean HDL-cholesterol did not vary between 1995 and 1998 for either men or women, or for the different age groups.
The prevalence of low HDL-cholesterol increased slightly in all age groups except in men aged 35-44 and in women aged 45-54. Overall, the prevalence of low HDL-cholesterol was 13.8% in 1995 and 15.8% in 1998 among men and 4.2% in 1995 and 5.4% in 1998 among women.
2.7.4 Fibrinogen
Fibrinogen is a major blood glycoprotein that plays an essential role in haemostasis (coagulation) and the maintenance of blood viscosity. High fibrinogen is an important primary cardiovascular risk factor. Epidemiological observations indicate that high plasma fibrinogen levels are strongly correlated with the frequency of two major thrombotic complications of atherosclerosis (hardening of the arteries), stroke and myocardial infarction. Moreover the Scottish Heart Health Study confirmed that plasma fibrinogen is not only a risk factor for coronary heart disease and stroke, but is also raised with family history of premature heart disease and with personal history of hypertension, diabetes, and presence of intermittent claudication.19
For fibrinogen levels (g/l), the arithmetic mean and median are presented in the tables. As these measures were very similar, the arithmetic mean is discussed. Both the laboratories and the method used for analysis were different in 1995 and 1998; inter-year comparisons have not been attempted because changes in methodology would affect comparability.
By age and sex
Mean fibrinogen was 2.6 g/l for men and 2.8 g/l for women. It increased with age in both sexes. Among men, it ranged from 2.2 g/l in those aged 16-24 to 3.1 g/l in those aged 65-74. Among women the range was from 2.6 g/l in those aged 16-24 to 3.2 g/l in those aged 65-74. Fibrinogen levels were slightly higher in women than in men in all age groups.
2.7.5 C-reactive protein
C-reactive protein (CRP) is a sensitive marker of inflammation. Levels of these acute phase proteins have been related to risk of coronary heart disease (CHD). Elevated levels of CRP are associated with increased risk of myocardial infarction (MI) or sudden death among those with stable and unstable angina pectoris,20 as well as with coronary heart disease in the elderly and coronary mortality among high-risk patients. The follow-up of the Multiple Risk Factor Intervention Trial (MRFIT) has documented a strong relationship between levels of C-reactive protein and subsequent risk of CHD deaths among cigarette smokers.21 Data from the US Physicians' Health Study raised the possibility that assessment of CRP may also provide a method of determining risk of future MI among apparently low-risk individuals, including non-smokers.22 In the literature there is no recommendation for a C-reactive protein threshold. The distribution of C-reactive protein was not normal, being very skewed to the left, so that the mean was not a good measure for the general level in the population. Quintile distributions are presented in this report. The categories of CRP defined on the basis of the quintile distribution, separately for men and women, are presented below.
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CRP quintiles (mg/l) |
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Men |
Women |
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Bottom quintile |
²0.4 |
²0.5 |
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2nd quintile |
0.5-0.9 |
0.5-1.1 |
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3rd quintile |
1.0-1.7 |
1.2-2.2 |
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4th quintile |
1.8-3.5 |
2.3-4.5 |
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Top quintile |
>3.5 |
>4.5 |
As a result, comparisons cannot be made for the total columns (since, by definition, each quintile is around 20%).
By age and sex
C-reactive protein generally increased with age in both men and women. Among men the proportion of informants who had a C-reactive protein level in the top quintile increased from 8.7% in those aged 16-24 to 38% in those aged 65-74. The corresponding figures for women were 13.7% and 33.3%.
2.8 PREVALENCE OF CARDIOVASCULAR DISEASE AND ITS RISK FACTORS
2.8.1 Definition of risk factors
Prospective cohort studies have shown that the absolute risk of cardiovascular disease in any individual is determined by a complex interplay of several factors.23 The purpose of this section is to look at the associations between cardiovascular disease and a variety of risk factors. For this section, risk factors were defined as follows.
2.8.2 Any cardiovascular disorder
In this section high blood pressure has not been considered separately as a risk factor because the definition of any cardiovascular disorder includes high blood pressure (see section 2.2.2).
Overall, the prevalence of risk factors was higher in those with a cardiovascular disorder than in those without. The exceptions were current cigarette smoking and alcohol consumption above the recommended weekly limit for men and women and being in a manual social class for men. The prevalence of current cigarette smoking was higher in those without a cardiovascular disorder for men (35.3% compared with 30.4%), although all of this difference was concentrated in the 45-64 age group. Among women there was little difference between the two groups: 30.6% of those with any CVD smoked compared with 32.9% of those with no CVD. Alcohol consumption above the recommended weekly limits was similar between the two groups for men (32.8% of those without CVD compared with 31.0%) and was higher in those without a cardiovascular disorder for women (15.6% compared with 8.2%). Men with a cardiovascular disorder were only slightly more likely to be in a manual social class than men without a cardiovascular disorder (55.6% of men with a cardiovascular disorder compared with 52.4% of men without), with most of this difference being concentrated in the oldest age group. The higher prevalence of each of the other risk factors for those with a cardiovascular disorder was fairly evenly distributed between the age groups with the exceptions of physical inactivity and manual social class for women. The higher prevalence of physical inactivity was concentrated in women aged 45-74 while the higher prevalence of being in a manual social class was concentrated in women aged 16-64.
2.8.3 Ischaemic heart disease or stroke
Overall, the prevalence of risk factors was higher in those with IHD or stroke than in those without with the exception of alcohol consumption above the recommended weekly limit and current cigarette smoking. Alcohol consumption above the recommended weekly limit was higher among those without IHD or stroke for both men and women (32.9% compared with 25.9% for men and 14.4% compared with 3.6% for women), although this could be an age effect. For men, current cigarette smoking was higher among those without IHD or stroke (34.7% compared with 27.2%); for women there was no difference. The prevalence of raised total cholesterol was similar for the two groups among men (18.1% in men with IHD or stroke compared with 16.8% in men without), but not among women (35.0% of those with IHD or stroke, 17.4% of those without).
2.8.4 Multivariate analysis of ischaemic heart disease or stroke and risk factors
This section examines the association between each risk factor and IHD or stroke after adjustment for all the other factors simultaneously and for age.
Physical activity, HDL-cholesterol and high blood pressure were significantly related to the prevalence of IHD or stroke in both men and women. The odds ratio was more than two times higher in inactive people (2.38 for men and 2.14 for women) than in active people and in people with high blood pressure (2.28 for men and 2.66 for women) than in those without high blood pressure. The odds ratio for low HDL-cholesterol was higher among women (2.89) than among men (2.07). Waist-hip ratio was significantly related to the prevalence of IHD among men but not among women. On the other hand, smoking and body mass were significant risk factors among women but not among men. Among women the odds ratio for current smokers was three times higher than for non-smokers while those with a BMI >=25 (Kg/m2) had an odds ratio twice as great as those without.
2.9 COMPARISONS BETWEEN SCOTLAND AND ENGLAND
This section analyses the differences between the Health Survey for Scotland 1998 and the Health Survey for England 1998 in the prevalence of cardiovascular disease and the blood analytes examined above. The Health Surveys for Scotland and England are similar in design and objectives. Comparisons are made with England as a whole, and with Northern England which includes the Northern & Yorkshire and North West regions.
2.9.1 Any cardiovascular disorder in Scotland, England and Northern England
Among men the prevalence of any cardiovascular disorder was generally similar in Scotland (23.6%) and England (25.5%) except for the oldest age group. In this age group, 65-74, the prevalence in Scotland was higher (57.9%) than in both England (51.8%) and Northern England (49.5%). Among women, the prevalence of any cardiovascular disorder was lower in Scotland than in England in the younger (up to age 34) and oldest (65-74) age groups. In the middle age groups women presented a higher prevalence in Scotland than in England, particularly in those aged 55-64 (44.8% in Scotland compared with 37.6% in England and 36.7% in Northern England).
2.9.2 Ischaemic heart disease or stroke in Scotland, England and Northern England
Overall, people in Scotland were slightly more likely to have IHD or stroke than people in England (7.2% in Scotland compared with 6.7% in England for men and 5.3% compared with 4.0% for women). The difference was statistically significant only in women. In both sexes prevalence of IHD or stroke in Scotland and England was similar for the younger age groups but it was higher in Scotland from age 45 onward and the differences increased with age. In the oldest (65-74) it was 31.0% in Scotland, 24.2% in England and 24.7% in Northern England. The corresponding figures for women aged 65-74 were 20.9% in Scotland, 15.6% in England and 16.3% in Northern England.
2.9.3 Rose angina symptoms and possible myocardial infarction in Scotland, England and Northern England
The prevalence of angina as assessed by the Rose Questionnaire was higher among men in Scotland than in England or Northern England, especially in the older age groups (from 55 onwards). Among women this prevalence did not show notable differences between Scotland and England.
On the other hand, the prevalence of possible myocardial infarction was slightly lower in Scotland than in England or Northern England in both men and women, although this difference was significant only between Scotland and England as a whole.
2.9.4 Blood analytes
Total cholesterol in Scotland, England and Northern England
Mean level of total cholesterol was similar in Scotland and England in all age groups for both men and women. Among men the proportion of informants who had a cholesterol level of 6.5 mmol/l or above was slightly higher in Scotland than in England in the central age groups (35-54) while in those aged 65-74 it was lower in Scotland (18.1%) than in England (26.3%) or Northern England (25.6%).
Among women the proportion of informants who had a cholesterol level of 6.5 mmol/l or above was lower in Scotland than in England, particularly in those aged 65-74 (43.3% in Scotland, 48.0% in England and 53.5% in Northern England).
HDL cholesterol in Scotland, England and Northern England
Mean HDL-cholesterol level did not differ between Scotland and England, being constant across all age groups among men (1.3 mmol/l) and women (1.5 mmol/l or 1.6 mmol/l) in both countries.
No significant difference was present between the two countries in the proportion of informants with an HDL-cholesterol level less than 1 mmol/l.
Fibrinogen in Scotland, England and Northern England
Overall, mean fibrinogen was slightly higher in Scotland (2.6 g/l for men and 2.8 g/l for women) than in England or Northern England (both 2.5 g/l for men and 2.7 g/l for women). The difference in mean fibrinogen between the two surveys was statistically significant in both men and women after adjustment for age.
C-reactive protein in Scotland, England and Northern England
There were no significant differences between Scotland and England in the proportion of informants who had a C-reactive protein level in the top quintile except for a higher percentage in Scotland for men aged 35-44 (17.8% compared with 13.1% in England).