A Role for Behavior in the Relationships Between Depression and Hostility and Cardiovascular Disease Incidence, Mortality, and All-Cause Mortality: the Prime Study.

BACKGROUND: Behavioral factors are important in disease incidence and mortality and may explain associations between mortality and various psychological traits. PURPOSE: These analyses investigated the impact of behavioral factors on the associations between depression, hostility and cardiovascular disease(CVD) incidence, CVD mortality, and all-cause mortality. METHODS: Data from the PRIME Study (N = 6953 men) were analyzed using Cox proportional hazards models, following adjustment for demographic and biological CVD risk factors, and other psychological traits, including social support. RESULTS: Following initial adjustment, both depression and hostility were significantly associated with both mortality outcomes (smallest SHR = 1.24, p < 0.001). Following adjustment for behavioral factors, all relationships were attenuated both when accounting for and not accounting for other psychological variables. Associations with all-cause mortality remained significant (smallest SHR = 1.14, p = 0.04). Of the behaviors included, the most significant contribution to outcomes was found for smoking, but a role was also found for fruit and vegetable intakes and high alcohol consumption. CONCLUSIONS: These findings demonstrate well-known associations between depression, hostility, and mortality and suggest the potential importance of behaviors in explaining these relationships.

Depression and mortality: artifact of measurement and analysis?

BACKGROUND: Previous research demonstrates various associations between depression, cardiovascular disease (CVD) incidence and mortality, possibly as a result of the different methodologies used to measure depression and analyse relationships. This analysis investigated the association between depression, CVD incidence (CVDI) and mortality from CVD (MCVD), smoking related conditions (MSRC), and all causes (MALL), in a sample data set, where depression was measured using items from a validated questionnaire and using items derived from the factor analysis of a larger questionnaire, and analyses were conducted based on continuous data and grouped data. METHODS: Data from the PRIME Study (N=9798 men) on depression and 10-year CVD incidence and mortality were analysed using Cox proportional hazards models. RESULTS: Using continuous data, both measures of depression resulted in the emergence of positive associations between depression and mortality (MCVD, MSRC, MALL). Using grouped data, however, associations between a validated measure of depression and MCVD, and between a measure of depression derived from factor analysis and all measures of mortality were lost. LIMITATIONS: Low levels of depression, low numbers of individuals with high depression and low numbers of outcome events may limit these analyses, but levels are usual for the population studied. CONCLUSIONS: These data demonstrate a possible association between depression and mortality but detecting this association is dependent on the measurement used and method of analysis. Different findings based on methodology present clear problems for the elucidation and determination of relationships. The differences here argue for the use of validated scales where possible and suggest against over-reduction via factor analysis and grouping.

Fruit and vegetable intake and smoking cessation.

BACKGROUND/OBJECTIVES: In cohort studies, fruit and vegetable (F&V) intake is associated with lower cardiovascular diseases (CVDs). Former smokers often have a higher F&V intake than current smokers. If a high intake of F&V precedes smoking cessation, the latter may explain the favorable association between F&V intake and CVD among smokers. The objective was to assess whether higher F&V intake precedes smoking cessation. SUBJECTS/METHODS: The study population comprised 1056 male smokers from Lille (France) and Belfast (Northern Ireland) aged 50-59 years on inclusion in 1991. At baseline, participants completed self-administered questionnaires related to smoking habits, demographic, socioeconomic factors and diet. At the 10-year follow-up, smoking habits were assessed by mailed questionnaire. RESULTS: After 10 years, 590 out of 1056 smokers had quit smoking (70.7% of smoker in Lille and 37.8% in Belfast). After adjusting for center, consumption of F&V was associated with quitting (odds ratio (OR) for high versus low F&V intake: 1.73; 95% confidence interval (CI): (1.22-2.45); P-trend=0.002). After further adjustment for sociodemographic factors, body mass index and medical diet, the association was still statistically significant (OR: 1.59; 95% CI (1.12-2.27); P-trend = 0.01). In a model fully adjusted for age, smoking intensity, alcohol consumption and physical activity, the association was no longer significant (P = 0.14). CONCLUSIONS: Higher F&V intake precedes smoking cessation. Hence, smoking cessation could affect the causal interpretation of the association between F&V and CVD in smokers.

Do lifestyle behaviours explain socioeconomic differences in all-cause mortality, and fatal and non-fatal cardiovascular events? Evidence from middle aged men in France and Northern Ireland in the PRIME Study.

OBJECTIVE: To examine the contribution of lifestyle behaviours to the socioeconomic gradient in all-cause mortality, and fatal and non-fatal cardiovascular events. METHOD: 10,600 men aged 50-59 years examined in 1991-1994 in Northern Ireland (NI) and France and followed annually for deaths and cardiovascular events for 10 years. Baseline smoking habit, physical activity, and fruit, vegetable, and alcohol consumption were assessed. RESULTS: All lifestyle behaviours showed marked socioeconomic gradients for most indicators in NI and France, with the exception of percentage of alcohol consumers in NI and frequency of alcohol consumption in NI and France. At 10 years, there were 544 deaths from any cause and 440 fatal and non-fatal cardiovascular events. After adjustment for country and age, socioeconomic gradients were further adjusted for lifestyle behaviours. For total mortality, the median residual contribution of lifestyle behaviours was 28% and for cardiovascular incidence, 41%. When cardiovascular risk factors were considered in conjunction with lifestyle behaviours these percentages increased to 38% and 67% respectively. CONCLUSION: Lifestyle behaviours contribute to the gradient in mortality and cardiovascular incidence between socioeconomic groups, particularly for cardiovascular incidence, but a substantial proportion of these differentials was not explained by lifestyle behaviours and cardiovascular risk factors.

Contribution of lifetime smoking habit in France and Northern Ireland to country and socioeconomic differentials in mortality and cardiovascular incidence: the PRIME Study.

BACKGROUND: This study examines the contribution of lifetime smoking habit to the socioeconomic gradient in all-cause and smoking-related mortality and in cardiovascular incidence in two countries. METHODS: 10,600 men aged 50-59 years were examined in 1991-4 in centres in Northern Ireland and France and followed annually for 10 years. Deaths and cardiovascular events were documented. Current smoking habit, lifetime smoking (pack-years) and other health behaviours were evaluated at baseline. As socio-occupational coding schemes differ between the countries seven proxy socioeconomic indicators were used. RESULTS: Lifetime smoking habit showed marked associations with most socioeconomic indicators in both countries, but lifetime smoking was more than 10 pack-years greater overall in Northern Ireland and smoking patterns differed. Total mortality was 49% higher in Northern Ireland than in France, and smoking-related mortality and cardiovascular incidence were 93% and 92% higher, respectively. Both lifetime smoking and fibrinogen contributed independently to these differentials, but together explained only 42% of the difference in total mortality between countries, adjusted for both biological and lifestyle confounders. Socioeconomic gradients were steeper for total and smoking-related mortality than for cardiovascular incidence. Residual contributions of lifetime smoking habit ranged from 6% to 34% for the seven proxy indicators of socioeconomic position for total and smoking-related mortality. Socioeconomic gradients in cardiovascular incidence were minimal following adjustment for confounders. CONCLUSION: In Northern Ireland and France lifetime smoking appeared to explain a significant part of the gradients in total and smoking-related mortality between socioeconomic groups, but the contribution of smoking was generally small for cardiovascular incidence.

Systemic chemokine levels, coronary heart disease, and ischemic stroke events: the PRIME study.

OBJECTIVES: To quantify the association between systemic levels of the chemokine regulated on activation normal T-cell expressed and secreted (RANTES/CCL5), interferon-γ-inducible protein-10 (IP-10/CXCL10), monocyte chemoattractant protein-1 (MCP-1/CCL2), and eotaxin-1 (CCL11) with future coronary heart disease (CHD) and ischemic stroke events and to assess their usefulness for CHD and ischemic stroke risk prediction in the PRIME Study. METHODS: After 10 years of follow-up of 9,771 men, 2 nested case-control studies were built including 621 first CHD events and 1,242 matched controls and 95 first ischemic stroke events and 190 matched controls. Standardized hazard ratios (HRs) for each log-transformed chemokine were estimated by conditional logistic regression. RESULTS: None of the 4 chemokines were independent predictors of CHD, either with respect to stable angina or to acute coronary syndrome. Conversely, RANTES (HR = 1.70; 95% confidence interval [CI] 1.05-2.74), IP-10 (HR = 1.53; 95% CI 1.06-2.20), and eotaxin-1 (HR = 1.59; 95% CI 1.02-2.46), but not MCP-1 (HR = 0.99; 95% CI 0.68-1.46), were associated with ischemic stroke independently of traditional cardiovascular risk factors, hs-CRP, and fibrinogen. When the first 3 chemokines were included in the same multivariate model, RANTES and IP-10 remained predictive of ischemic stroke. Their addition to a traditional risk factor model predicting ischemic stroke substantially improved the C-statistic from 0.6756 to 0.7425 (p = 0.004). CONCLUSIONS: In asymptomatic men, higher systemic levels of RANTES and IP-10 are independent predictors of ischemic stroke but not of CHD events. RANTES and IP-10 may improve the accuracy of ischemic stroke risk prediction over traditional risk factors.

The transcobalamin (TCN2) 776C>G polymorphism affects homocysteine concentrations among subjects with low vitamin B(12) status.

BACKGROUND/OBJECTIVES: Methionine synthase catalyzes the conversion of 5-methyltetrahydrofolate to tetrahydrofolate and homocysteine (Hcy) to methionine using vitamin B(12) as a cofactor. Transcobalamin is the main transporter of vitamin B(12) from blood into cells. This study was undertaken to assess the relationship between the transcobalamin P259R (TCN2 776C>G) polymorphism and both serum vitamin B(12) and total Hcy (tHcy) levels. SUBJECTS/METHODS: The population comprised 613 men from Northern Ireland, aged 30-49 years, for whom tHcy, serum vitamin B(12) and serum folate concentrations were available. TCN2 776C>G genotypes were determined using a TaqMan 5' nuclease Real-Time PCR assay. Standard statistical tests of association were applied to assess the relationships between the polymorphism and phenotypic variables. RESULTS: The TCN2 776CC homozygous genotype was associated with lower serum vitamin B(12) concentrations compared with the 776CG (P(unadjusted)=0.01; P(adjusted)=0.03) and 776GG genotypes (P(unadjusted)=0.015; P(adjusted)=0.045). Among individuals with vitamin B(12) concentrations in the lower half of the distribution, tHcy concentrations were higher in TCN2 776GG homozygotes than in individuals with the other genotypes (P(unadjusted)=0.015; P(adjusted)=0.06). CONCLUSIONS: These data suggest that, relative to transcobalamin with arginine at position 259 (776G), transcobalamin with proline at this position (776C) is either more efficient at vitamin B(12) transport from blood to tissues or has higher affinity for vitamin B(12). Furthermore, vitamin B(12) status influences the relationship between TCN2 776C>G genotype and tHcy concentrations. Thus, the TCN2 776C>G polymorphism may contribute to the risk of pathologies associated with a low B(12), and high tHcy phenotype.

Plasma free fatty acid patterns and their relationship with CVD risk in a male middle-aged population.

BACKGROUND/OBJECTIVES: The role of individual fatty acids in the development of cardiovascular disease (CVD) is well established, but the effects of an overall pattern of fatty acids in CVD risk has yet to be elucidated. Circulating fatty acid levels are related to metabolic disturbances associated with the metabolic syndrome and CVD, due to disturbances in the activity of enzymes that catalyse fatty acid desaturation (Delta-desaturases). Therefore, we determined patterns of fatty acids and estimated desaturase activity in plasma and analysed how these patterns were related to a 10-year CVD risk estimates in a middle-aged male population in Northern Ireland. SUBJECTS/METHODS: Principal components analysis (PCA) was performed for defining fatty acid patterns in 379 men aged 30-49 years. Logistic regression analyses were then carried out for analysing the relationship between these fatty acid patterns and the 10-year CVD risk estimates. RESULTS: The PCA generated three high fatty acid patterns: high saturated fatty acid (SFA), high omega 3 fatty acid (omega 3) and high monosaturated fatty acid (MNFA). Results from logistic regression analyses show that a 1 s.d. increase in the SFA pattern score was significantly and positively associated with an increase in the 10-year CVD risk category (odds ratio 1.71, 95% confidence interval 1.33-2.21, P<0.0001) even after adjustment for lifestyle factors. There were no significant relationships between the other two pattern scores and the 10-year CVD risk. CONCLUSIONS: An unhealthy fatty acid pattern representing both dietary intake and in vivo fatty acid metabolism is related to the 10-year CVD risk estimates and provide evidence that, as with dietary patterns, the synergistic effect of multiple fatty acids may be more important in relation to the development of CVD risk.

Residual cardiovascular risk in treated hypertension and hyperlipidaemia: the PRIME Study.

Although pharmacological treatments of hypertension and dyslipidaemia are both associated with a reduction in cardiovascular risk, little is known about the degree of cardiovascular risk remaining in treated individuals, by assessing the levels of their risk factors achieved, that is their 'residual cardiovascular risk'. We then used the data from the Prospective Epidemiological Study of Myocardial Infarction (PRIME), which involved 9649 men aged 50-59 years, from France and Northern Ireland with a 10-year follow-up, to test the presence of specific residual cardiovascular risks of coronary heart disease, stroke, total of fatal and non-fatal cardiovascular events and cardiovascular mortality, in patients treated with antihypertensive agents or lipid-lowering agents. In the whole cohort, a total of 796 patients developed a fatal or non-fatal cardiovascular event. Antihypertensive drug use at baseline was significantly associated (RR=1.50, 95% CI: 1.25-1.80) with total cardiovascular event risk, but not lipid-lowering drug use, after adjusting for classic risk factors (age, smoking, total cholesterol, high-density lipoprotein cholesterol, systolic blood pressure and diabetes). Similar results were obtained for coronary heart disease (RR=1.46, 95% CI: 1.18-1.80), stroke (RR=1.75, 95% CI: 1.14-2.70) and cardiovascular death (RR=1.62, 95% CI: 1.02-2.58), but neither for total death (RR=1.15, 95% CI: 0.89-1.48) nor for non-cardiovascular death (RR=1.00, 95% CI: 0.74-1.36). For any cardiovascular end point, residual risks did not globally differ according to the antihypertensive drug class prescribed at baseline. In conclusion, treatment with antihypertensive agents, but not with lipid-lowering agents, was associated with a sizeable residual cardiovascular risk, suggesting that more efficient risk reduction strategies in hypertension should be developed as a priority.

Systematically missing confounders in individual participant data meta-analysis of observational cohort studies.

One difficulty in performing meta-analyses of observational cohort studies is that the availability of confounders may vary between cohorts, so that some cohorts provide fully adjusted analyses while others only provide partially adjusted analyses. Commonly, analyses of the association between an exposure and disease either are restricted to cohorts with full confounder information, or use all cohorts but do not fully adjust for confounding. We propose using a bivariate random-effects meta-analysis model to use information from all available cohorts while still adjusting for all the potential confounders. Our method uses both the fully adjusted and the partially adjusted estimated effects in the cohorts with full confounder information, together with an estimate of their within-cohort correlation. The method is applied to estimate the association between fibrinogen level and coronary heart disease incidence using data from 154,012 participants in 31 cohorts

Paraoxonase activity and coronary heart disease risk in healthy middle-aged males: the PRIME study.

OBJECTIVE: Classic coronary heart disease (CHD) risk factors fail to explain the large gradient in CHD incidence between Northern Ireland and France. The Prospective Epidemiological Study of Myocardial Infarction (PRIME) study, a multicentre prospective study of 10,593 middle-aged males, investigated novel risk factors in these populations. We tested the hypotheses that (1) higher paraoxonase activity is associated with decreased CHD risk and (2) PON55 LL genotype is associated with increased CHD risk. METHODS: Paraoxonase activity was measured in 299 men who had developed CHD at 5-year follow-up and in 576 matched controls. DNA was available from 247 cases and 433 controls for genotyping for the PON55 polymorphism. RESULTS: There was no significant difference in paraoxonase activity between cases and controls (geometric means 73.8 and 74.2U/l; p=0.81). There was no significant difference in CHD risk between fifths of paraoxonase activity either before (p=0.55) or after adjustment for classical risk factors (p=0.58). There was no significant association between genotype and CHD risk; relative to the LL genotype, the OR (95% CI) for the LM and MM genotypes were 0.92 (0.66-1.29) and 0.83 (0.50-1.36), respectively. The frequency of the L allele in cases (66.6%) and controls (64.5%) did not differ significantly, p=0.45. CONCLUSIONS: These findings suggest that neither paraoxonase activity nor PON55 genotype is associated with CHD risk in males in the PRIME study.

The Emerging Risk Factors Collaboration: analysis of individual data on lipid, inflammatory and other markers in over 1.1 million participants in 104 prospective studies of cardiovascular diseases.

Many long-term prospective studies have reported on associations of cardiovascular diseases with circulating lipid markers and/or inflammatory markers. Studies have not, however, generally been designed to provide reliable estimates under different circumstances and to correct for within-person variability. The Emerging Risk Factors Collaboration has established a central database on over 1.1 million participants from 104 prospective population-based studies, in which subsets have information on lipid and inflammatory markers, other characteristics, as well as major cardiovascular morbidity and cause-specific mortality. Information on repeat measurements on relevant characteristics has been collected in approximately 340,000 participants to enable estimation of and correction for within-person variability. Re-analysis of individual data will yield up to approximately 69,000 incident fatal or nonfatal first ever major cardiovascular outcomes recorded during about 11.7 million person years at risk. The primary analyses will involve age-specific regression models in people without known baseline cardiovascular disease in relation to fatal or nonfatal first ever coronary heart disease outcomes. This initiative will characterize more precisely and in greater detail than has previously been possible the shape and strength of the age- and sex-specific associations of several lipid and inflammatory markers with incident coronary heart disease outcomes (and, secondarily, with other incident cardiovascular outcomes) under a wide range of circumstances. It will, therefore, help to determine to what extent such associations are independent from possible confounding factors and to what extent such markers (separately and in combination) provide incremental predictive value.

Type A behaviour and consumption of an atherogenic diet: no association in the PRIME study.

It has previously been suggested that the association between Type A behaviour and coronary heart disease (CHD) may be mediated through diet. This analysis investigates associations between Type A behaviour and diet, with particular focus on foods high in saturated fats and cholesterol (cake, cheese, eggs and fried potatoes), foods high in unsaturated fats (fish and nuts), and fruit and vegetables. The analysis was conducted on data collected from 10,602 men from Northern Ireland and France screened for inclusion in the PRIME cohort study. Type A behaviour was measured using the Framingham Type A Behaviour Patterns Questionnaire, diet was measured using a Food Frequency Questionnaire and various demographic details were also assessed. Levels of Type A behaviour and intakes of all food groups were similar to previous studies. Using regression, Type A behaviour was significantly associated with diet, and specifically with a higher consumption of cheese and vegetables in Northern Ireland, and a higher consumption of cake, fish and vegetables in France. These associations are most plausibly explained as a result of lifestyle, although the possibility of independent associations between Type A behaviour and diet remains. The work is limited by the use of questionnaires, but the findings available suggest that Type A behaviour is unlikely to be associated with the consumption of a diet that has previously been linked to CHD. These findings suggest that any association between Type A behaviour and CHD is unlikely to be mediated through diet.

Depressed mood and dietary fish intake: direct relationship or indirect relationship as a result of diet and lifestyle?

Previous studies have suggested an association between depressed mood and the dietary intake of fish. In all cases, however, dietary fish intake has been considered at the exclusion of all other aspects of the diet. This analysis investigates associations between depressed mood and dietary fish intake, while also concurrently investigating intake of a number of other dietary components. The analysis is conducted on data from 10,602 men from Northern Ireland and France screened for inclusion into the PRIME cohort study. Depressed mood was assessed using a self-report questionnaire based on the Welsh Pure Depression sub-scale of the Minnesota Multiphasic Personality Inventory, diet was assessed using a Food Frequency Questionnaire, and limited demographics were also measured. Using regression, depressed mood is initially inversely associated with dietary fish intake. On inclusion of all other dietary variables, the strength of this relationship reduces but remains, and significant associations with a number of other foods are also found. On additional inclusion of all demographic variables, the strength of the above relationships again reduces, and associations with various measures of socio-economic status and education are also significant. These findings suggest that depressed mood is associated with fish intake both directly, and indirectly as part of a diet that is associated with depression and as part of a lifestyle that is associated with depression. Additional support for these conclusions is also provided in the pattern of associations between depressed mood and diet in the two countries. The relative contributions of fish intake to depressed mood both directly and indirectly are yet to be determined. However, while diet is not measured and until lifestyle can be adequately measured, the potential roles of diet and lifestyle in the association between depressed mood and dietary fish intake should not be ignored.

Homocysteine and coronary heart disease risk in the PRIME study.

INTRODUCTION: Despite recent meta-analyses suggesting that homocysteine is an independent predictor of coronary heart disease (CHD), there is debate regarding whether elevated homocysteine may be deleterious only in the presence of other risk factors, with which it acts synergistically to exert a multiplicative effect on CHD risk, emerging only as a CHD predictor in patients with pre-existing risk factors. The Prospective Epidemiological Study of Myocardial Infarction (PRIME) Study is a multicentre prospective study of 10593 men from France and Northern Ireland, investigating cardiovascular risk factors. We investigated: (1) whether higher homocysteine is associated with increased CHD risk in the PRIME case-control cohort; (2) whether homocysteine interacts synergistically with pre-existing CHD risk factors. METHODS: Homocysteine was measured in 323 participants who had developed CHD at 5-year follow-up and in 638 matched controls. RESULTS: There was no significant difference in homocysteine between cases and controls (p=0.18). Homocysteine was significantly higher in current smokers (geometric mean mumol/l (interquartile range mumol/l) 9.45 (7.43, 11.75)) compared with non-smokers (8.90 (7.32, 10.70); p=0.007). There was a significant interaction between homocysteine, smoking and CHD risk (chi2=10.29, d.f.=2, p=0.006). CONCLUSIONS: These findings suggest that elevated homocysteine is significantly associated with CHD risk in current smokers.

Metabolic syndrome and coronary heart disease risk in a population-based study of middle-aged men from France and Northern Ireland. A nested case-control study from the PRIME cohort.

Metabolic Syndrome (MetS) was found associated with an increased CHD risk in several studies but data about this relationship in Southern Europe are lacking. We studied the association of MetS according to three different indexes (the National Cholesterol Education Program's definition (NCEP), a modified World Health Organization's definition (WHO) and the recent International Diabetes Federation's definition (IDF)) with CHD risk in a case-control study nested within the PRIME cohort, composed of subjects from France (Southern Europe) and Belfast (Northern Europe). The PRIME prospective study is composed of 10 592 men, aged 50-59 at baseline and followed for 5 years. Subjects included in this nested case-control study were 296 cases of incident CHD and 540 controls, who remained free of CHD during the 5 years of follow-up of the PRIME cohort and matched for age, recruitment centre and recruitment date. All subjects had questionnaires and a medical examination at baseline, and a blood sample was taken. Using the IDF's, the WHO's and the NCEP's definitions respectively, the frequency of MetS was 38.9%, 35.5% and 29.7% in cases and 32.4%, 28.7% and 22.6% in controls. After adjustment for physical activity, smoking and drinking habits, MetS was associated with CHD risk whichever the definition used (ORIDF=1.41 [1.02-1.95], P<0.04, ORWHO=1.40 [1.01-1.94], P<0.05 and ORNCEP=1.46[1.04-2.04], P<0.04). These results were homogeneous in France (low risk of CHD) and Belfast (high risk of CHD). Our results add further evidence that MetS is predictive of CHD risk in middle-aged men from Northern and Southern Europe, and highlight differences between the three definitions studied.

Plasma fibrinogen level and the risk of major cardiovascular diseases and nonvascular mortality: an individual participant meta-analysis.

CONTEXT: Plasma fibrinogen levels may be associated with the risk of coronary heart disease (CHD) and stroke. OBJECTIVE: To assess the relationships of fibrinogen levels with risk of major vascular and with risk of nonvascular outcomes based on individual participant data. DATA SOURCES: Relevant studies were identified by computer-assisted searches, hand searches of reference lists, and personal communication with relevant investigators. STUDY SELECTION: All identified prospective studies were included with information available on baseline fibrinogen levels and details of subsequent major vascular morbidity and/or cause-specific mortality during at least 1 year of follow-up. Studies were excluded if they recruited participants on the basis of having had a previous history of cardiovascular disease; participants with known preexisting CHD or stroke were excluded. DATA EXTRACTION: Individual records were provided on each of 154,211 participants in 31 prospective studies. During 1.38 million person-years of follow-up, there were 6944 first nonfatal myocardial infarctions or stroke events and 13,210 deaths. Cause-specific mortality was generally available. Analyses involved proportional hazards modeling with adjustment for confounding by known cardiovascular risk factors and for regression dilution bias. DATA SYNTHESIS: Within each age group considered (40-59, 60-69, and > or =70 years), there was an approximately log-linear association with usual fibrinogen level for the risk of any CHD, any stroke, other vascular (eg, non-CHD, nonstroke) mortality, and nonvascular mortality. There was no evidence of a threshold within the range of usual fibrinogen level studied at any age. The age- and sex- adjusted hazard ratio per 1-g/L increase in usual fibrinogen level for CHD was 2.42 (95% confidence interval [CI], 2.24-2.60); stroke, 2.06 (95% CI, 1.83-2.33); other vascular mortality, 2.76 (95% CI, 2.28-3.35); and nonvascular mortality, 2.03 (95% CI, 1.90-2.18). The hazard ratios for CHD and stroke were reduced to about 1.8 after further adjustment for measured values of several established vascular risk factors. In a subset of 7011 participants with available C-reactive protein values, the findings for CHD were essentially unchanged following additional adjustment for C-reactive protein. The associations of fibrinogen level with CHD or stroke did not differ substantially according to sex, smoking, blood pressure, blood lipid levels, or several features of study design. CONCLUSIONS: In this large individual participant meta-analysis, moderately strong associations were found between usual plasma fibrinogen level and the risks of CHD, stroke, other vascular mortality, and nonvascular mortality in a wide range of circumstances in healthy middle-aged adults. Assessment of any causal relevance of elevated fibrinogen levels to disease requires additional research.

Education, socioeconomic and lifestyle factors, and risk of coronary heart disease: the PRIME Study.

BACKGROUND: Socioeconomic differentials have been described in the risk of coronary heart disease (CHD) but the extent to which these differentials are explained by lifestyle factors has been examined to a lesser degree. We have examined the contribution of socio-economic factors to risk of CHD in a large cohort study in France and Northern Ireland. METHODS: In all, 10 593 men aged 50-59 years were examined between 1991 and 1994 in centres in Northern Ireland, Lille, Strasbourg, and Toulouse. Details were obtained for a number of socio-economic indicators from the men at the baseline examination. Men were also screened for evidence of CHD and followed annually by questionnaire for incident cases of coronary disease. Coronary events (coronary deaths, myocardial infarction, and angina) were documented by clinical records and were reviewed by an independent medical committee. RESULTS: In all, 842 men (8%) showed some evidence of CHD at screening examination and these men were more likely to be living in poorer material circumstances, be unemployed, or have had less full-time education than men without CHD at screening in both France and Northern Ireland. These relationships persisted following adjustment for all known risk factors for CHD. Among men who were initially free of CHD there were clear socio-economic differentials (years of full-time education, unemployment, and educational level) in the distribution of several risk factors for CHD, notably smoking habit (which differs in France and Northern Ireland), systolic blood pressure, body mass index, and fibrinogen. Total cholesterol in contrast showed no socio-economic differential whilst those with a shorter period of full-time education and the unemployed tended to be high consumers of alcohol. In this cohort of men free of CHD at baseline few socio-economic indicators showed relationships with risk of CHD by 5 years of follow-up. Only years in full education, educational level, and unemployment status when adjusted only for age and country showed significant relationships with CHD risk, but these became non-significant following adjustment for major CHD risk factors. CONCLUSIONS: Socio-economic differentials in long-term risk of CHD are apparent in both cohorts of men from France and Northern Ireland, particularly in men with evidence of CHD at baseline. Among men free of CHD at baseline, although there is strong evidence of socio-economic differentials in cardiovascular risk factors these do not contribute independently to risk of CHD at 5 years of follow-up in this large cohort of men from France and Northern Ireland.

The obesity epidemic: prospects for prevention.

Some 20-25% of UK adults are obese according to the WHO criterion (BMI >/=30 kg/m(2)). Type 2 diabetes, increasingly recognized as a major complication of overweight and obesity, is beginning to appear in UK adolescents, following the trends in the US. Epidemiological data indicate that the prevalence of overweight and obesity has doubled or tripled in the past few decades in the US, in Europe, and even in many developing countries. Thus obesity is increasingly seen as a public health problem requiring concerted action by both governmental and non-governmental organizations. A sound understanding of the root causes is crucial, if strategies for the prevention and treatment of this epidemic are to be developed. Many epidemiological studies suggest that physical activity at work, school or at leisure has declined to minimal levels, and that sedentary behaviours such as television viewing and computer games have become major pastimes. Thus energy requirements are substantially less than those for recent generations. Further, the food industry produces high-calorie foods which children and adults consume as snack meals, giving a substantial surfeit to their daily energy requirement. In children, a few school-based, preventive intervention trials have shown some promising results. Many negative trials have also been reported, and practical difficulties remain in the widespread implementation of appropriate protocols. Initiatives have been introduced by the government to increase the physical education syllabus in school to a minimum of 2 h/week, and the promotion of fruit and vegetables. Further research is required on the physiological and psychological causes of overweight and obesity in children and adults, and randomized, controlled, school and community-based trials are required to pilot preventative initiatives. Monitoring of the progress in prevention at both organizational and outcome level is required, and also of adverse outcomes such as a rise in the prevalence of eating disorders.

C-reactive protein, fibrin D-dimer, and risk of ischemic heart disease: the Caerphilly and Speedwell studies.

BACKGROUND: There is increasing interest in the predictive value of C-reactive protein (CRP) and fibrin D-dimer in the prediction of ischemic heart disease (IHD). We assessed their joint and independent associations with IHD in a large combined analysis of 2 population cohorts. METHODS AND RESULTS: Men aged 49 to 66 years from the general populations of Caerphilly and Speedwell were studied between 1982 and 1988 and re-examined for new IHD events at fixed intervals of approximately 105 months (Caerphilly) and 75 months (Speedwell). 3213 men had CRP and D-dimer measured at baseline and 351 (11%) had a new IHD event. Mean levels of CRP and D-dimer were significantly higher among men in whom IHD developed. The relative odds of IHD in men in the top 20% of the distribution of CRP was 2.97 (95% CI, 2.04, 4.32) and for D-dimer was 2.40 (95% CI, 1.69, 3.40); CRP and D-dimer had additive effects on risk of IHD. Multivariate analysis reduced the size of the relative odds, which remained significant for D-dimer. CONCLUSIONS: Both inflammatory and thrombogenic markers are important (and potentially additive) predictors of coronary risk.