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The role of preclinical atherosclerosis in the explanation of educational differences in incidence of coronary events

      Abstract

      The associations between educational level, preclinical carotid atherosclerosis and incident coronary events (CE), were investigated in a general population sample of 5399 Swedish middle-aged men and women without history of cardiovascular disease (CVD) over a median follow-up of 8.7 years. Presence of carotid plaque (focal intima-media thickness (IMT) >1.2 mm) was determined by B-mode ultrasound. In the age- and sex-adjusted model, there was an inverse relationship between educational level and risk of future CE (p for trend = 0.002). To explore if there were education differences between groups with similar degrees of preclinical carotid atherosclerosis stratified analyses were made. Those with low educational level without carotid plaque showed a slightly increased hazard rate ratio (HRR), 1.14 (95% CI: 0.65, 1.97), compared to those with high educational level without carotid plaque (reference group). For those with high educational level with carotid plaque the HRR was 1.53 (95% CI: 0.92, 2.55). Having both low educational level and carotid plaque was associated with a HRR of 2.72 (95% CI: 1.72, 4.31). Individuals with plaque generally had more unfavourable cardiovascular risk factor levels, regardless of educational level. However, after risk factor adjustment those with both low education and carotid plaque still had a two-fold increased risk of CE. The results imply that differences in the prevalence of preclinical atherosclerosis seem important in explaining education differences in future coronary morbidity.

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      References

        • Lynch J.W.
        • Kaplan G.A.
        • Salonen R.
        • Cohen R.D.
        • Salonen J.T.
        Socioeconomic status and carotid atherosclerosis.
        Circulation. 1995; 92: 1786-1792
        • Rosvall M.
        • Östergren P-O.
        • Hedblad B.
        • Isacsson S-O.
        • Janzon L.
        • Berglund G.
        Occupational status, educational level and the prevalence of carotid atherosclerosis in a general population sample of middle-aged Swedish men and women. Results from the Malmö Diet and Cancer Study.
        Am J Epidemiol. 2000; 152: 334-346
        • Diez-Roux A.V.
        • Nieto J.
        • Tyroler H.A.
        • Crum L.D.
        • Szklo M.
        Social inequalities and atherosclerosis.
        Am J Epidemiol. 1995; 141: 960-972
        • Chambless L.E.
        • Heiss G.
        • Folsom A.R.
        • Rosamond W.
        • Szklo M.
        • Sharrett A.R.
        • Clegg L.X.
        Association of coronary heart disease incidence with carotid arterial wall thickness and major risk factors: the Atherosclerosis Risk in Communities (ARIC) Study, 1987–1993.
        Am J Epidemiol. 1997; 146: 483-494
        • Bots M.L.
        • Hoes A.W.
        • Koudstaal P.J.
        • Hofman A.
        • Grobbee D.E.
        Common carotid intima- media thickness and risk of stroke and myocardial infarction: the Rotterdam Study.
        Circulation. 1997; 96: 1432-1437
        • O’Leary D.H.
        • Polak J.F.
        • Kronmal R.A.
        • Manolio T.A.
        • Burke G.L.
        • Wolfson Jr, S.K.
        Carotid-artery intima and media thickness as a risk factor for myocardial infarction and stroke in older adults. Cardiovascular Health Study Collaborative Research Group.
        N Engl J Med. 1999; 340: 14-22
        • Rosvall M.
        • Janzon L.
        • Berglund G.
        • Engström G.
        • Hedblad B.
        Incident coronary events and case-fatality in relation to common carotid IMT.
        J Intern Med. 2005; 257: 430-437
        • Manjer J.
        • Carlsson S.
        • Elmståhl S.
        • et al.
        The Malmö diet and cancer study: representivity, cancer incidence and mortality in participants and non-participants.
        Eur J Cancer Prev. 2001; 10: 489-499
      1. Persson J. Ultrasound and atherosclerosis. Evaluation of methods, risk factors and intervention. Thesis. Department of Medicine, Lund University, Malmö, Sweden 1997.

        • Wendelhag I.
        • Gustavsson T.
        • Suurkula M.
        • Berglund G.
        • Wikstrand J.
        Ultrasound measurement of wall thickness in the carotid artery: fundamental principles and description of a computerized image analyzing system.
        Clin Physiol. 1991; 11: 565-577
        • Taylor H.L.
        • Jacobs D.
        • Schuker B.
        • Knudsen J.
        • Leon A.
        • Debacker G.
        A questionnaire for the assessment of leisure time physical activities.
        J Chron Dis. 1978; 31: 741-755
      2. Treatment of Hyperlipidemia [in Swedish]. Information from the Medical Products Agency in Sweden. 1995;3:178–87.

        • Anonymous
        Causes of death 1995.
        The National Board of Health and Welfare, Centre of Epidemiology, Stockholm1997
        • Tydén P.
        • Hansen O.
        • Janzon L.
        Intra-urban variations in incidence and mortality in myocardial infarction. A study from the myocardial infarction register in the city of Malmö, Sweden.
        Eur Heart J. 1998; 19: 1795-1801
        • World Health Organisation
        International classification of diseases.
        World Health Organisation, Geneva1977 (Ninth Revision (ICD-9))
        • Rothman K.
        Causal inference in biology.
        in: Rothman K. Modern epidemiology. Little, Brown and Company, Boston/Toronto1986: 7-21
        • Engström G.
        • Tydén P.
        • Berglund G.
        • Hansen O.
        • Hedblad B.
        • Janzon L.
        Incidence of myocardial infarction in women. A cohort study of risk factors and modifiers of effect.
        J Epidemiol Commun Health. 2000; 54: 104-107
        • Falk E.
        • Shah P.K.
        • Fuster V.
        Coronary plaque disruption.
        Circulation. 1995; 92: 657-671
        • Kuh D.
        • Davey-Smith G.
        The life course and adult chronic disease: an historical perspective with particular reference to coronary heart disease.
        in: Kuh D. Ben-Shlomo Y. A life course approach to chronic disease epidemiology. Oxford University Press, New York, NY1997: 15-41
        • Kuh D.
        • Power C.
        • Bartley M.
        Social pathways between childhood and adult health.
        in: Kuh D. Ben-Shlomo Y. A life course approach to chronic disease epidemiology. Oxford University Press, New York, NY1997: 169-198
        • Coronary Prevention Group
        Children at risk: should the prevention of coronary heart disease begin in childhood.
        Coronary Heart Prevention Group, London, UK1989
      3. Lindström M. Social participation, social capital and socioeconomic differences in health-related behaviours. An Epidemiological Study. Thesis. Lund: Bloms Tryckeri, 2000.

      4. Hallqvist J. Socioeconomic differences in myocardial risk. Epidemiological analyses of causes and mechanisms. Thesis. Department of Public Health Sciences, Division of Social Medicine, Stockholm, Sweden 1998.

        • Lynch J.
        • Kaplan G.
        Socioeconomic position.
        in: Berkman L. Kawachi I. Social epidemiology. Oxford University Press, Oxford2000
      5. Wamala SP. Socioeconomic status and cardiovascular vulnerability in women. Psychosocial, behavioral and biological mediators. Thesis. Department of Public Health Sciences, Division of Preventive Medicine, Stockholm, Sweden, 1999.

        • Winkleby M.A.
        • Jatulis D.E.
        • Frank E.
        • Fortmann S.P.
        Socioeconomic status and health: How education, income and occupation contribute to risk factors for cardiovascular disease.
        Am J Public Health. 1992; 82: 816-820
        • Kunst A.E.
        • Mackenbach J.P.
        The size of mortality differences associated with educational level in nine industrialized countries.
        Am J Public Health. 1994; 84: 932-937