Abstract
Objectives To investigate the association between occupational social class and cardiovascular disease (CVD) incidence, and the extent to which classical and lifestyle risk factors explain such relationships, and if any differences persist after 65 years of age. Design, Setting and Participants Prospective population study of 22,478 men and women aged 39–79 years living in the general community in Norfolk, United Kingdom, recruited using general practice age-sex registers in 1993–1997 and followed up for total mortality to 2006. Main results In both men and women an inverse relationship was observed between social class and CVD incidence, with a relative risk of social class V compared to I of 1.90 in men (95% CI 1.47 to 2.47, P < 0.001) and 1.90 in women (95% CI 1.45 to 2.49, P < 0.001). Adjusting for classical and lifestyle risk factors (age, smoking, BMI, systolic blood pressure, total blood cholesterol, history of diabetes, physical activity, weekly alcohol intake and plasma vitamin C levels) had little effect in men; the relative risk of social class V compared to I of 1.70 (95% CI 1.31 to 2.22, P < 0.001), while there was some attenuation seen in women, relative risk of social class V compared to I of 1.56 (95% CI 1.18 to 2.05, P = 0.011). The association persisted in men and women aged ≥65 years. Conclusions Some but not all of the socioeconomic differential in CVD incidence can be explained by potentially modifiable classical and lifestyle risk factors. Low social class remains a risk factor for CVD after age 65 years. Further understanding of the mechanisms underlying the association is needed if we are to reduce inequalities in health.
Similar content being viewed by others
Abbreviations
- BMI:
-
Body mass index
- CVD:
-
Cardiovascular disease
- EPIC-Norfolk:
-
European Prospective Investigation of Cancer and Nutrition
- ICD:
-
International Classification of Disease
- SES:
-
Socioeconomic status
References
British Heart Foundation. 2007 Coronary Heart Disease Statistics. British Heart Foundation. 2007.
Marmot MG, Adelstein AM, Robinson N, Rose GA. Changing social-class distribution of heart disease. Br Med J. 1978;2(6145):1109–12.
Heller R, Williams H, Sittampalam Y. Social class and ischaemic heart disease: use of the male:female ratio to identify possible occupational hazards. J Epidemiol Community Health. 1984;38(3):198–202.
Emberson JR, Whincup PH, Morris RW, Walker M. Social class differences in coronary heart disease in middle-aged British men: implications for prevention. Int J Epidemiol. 2004;33(2):289–96.
Coulthard M, Chow Y, Dattani N, White C, Baker A, Johnson B. Health. In: Babb Penny, Martin Jean, Haezewindt P, editors. Focus on social inequalities. London: Office for National Statistics; 2004. p. 69–84.
Rose G, Marmot MG. Social class and coronary heart disease. Br Heart J. 1981;45(1):13–9.
Woodward M, Shewry MC, Cairns S, Smith W, Tunstall-Pedoe H. Social status and coronary heart disease: results from the Scottish heart health study. Prev Med. 1992;21(1):136–48.
Kaplan GA, Keil JE. Socioeconomic factors and cardiovascular disease: a review of the literature. Circulation. 1993;88(4 pt 1):1973–98.
Myint PK, Luben RN, Welch AA, Bingham SA, Wareham NJ, Khaw KT. Effect of age on the relationship of occupational social class with prevalence of modifiable cardiovascular risk factors and cardiovascular diseases. A population-based cross-sectional study from European Prospective Investigation into Cancer—Norfolk (EPIC-Norfolk). Gerontology 2006;52(1):51–8.
McFadden EC, Luben RN, Wareham NJ, Bingham SA, Khaw KT. Occupational social class, educational level, smoking and body mass index, and cause-specific mortality in men and women: a prospective study in the European Prospective Investigation of Cancer and Nutrition in Norfolk (EPIC-Norfolk) cohort. In press 2008.
Day N, Oakes S, Luben R, Khaw KT, Bingham S, Welch A, et al. EPIC-Norfolk: study design and characteristics of the cohort. European Prospective Investigation of Cancer. Br J Cancer. 1999;80(1):95–103.
Shohaimi S, Luben R, Wareham N, Day N, Bingham S, Welch A, et al. Residential area deprivation predicts smoking habit independently of individual educational level and occupational social class. A cross sectional study in the Norfolk cohort of the European Investigation into Cancer (EPIC-Norfolk). J Epidemiol Community Health. 2003;57(4):270–6.
Elias P, Halstead K, Prandy K. CASOC: Computer-Assisted Standard Occupational Coding. London: HMSO; 1993.
Smith MR, Kinmonth A-L, Luben RN, Bingham S, Day NE, Wareham NJ, et al. Smoking status and differential white cell count in men and women in the EPIC-Norfolk population. Atherosclerosis 2003;169(2):331–7.
Sargeant L, Wareham N, Bingham S, Day N, Luben R, Oakes S, et al. Vitamin C and hyperglycemia in the European Prospective Investigation into Cancer–Norfolk (EPIC-Norfolk) study: a population-based study. Diabetes Care. 2000;23(6):726–32.
Sargeant LA, Khaw K-T, Bingham S, Day NE, Luben RN, Oakes S, et al. Cigarette smoking and glycaemia: the EPIC-Norfolk study. Int J Epidemiol. 2001;30(3):547–54.
Wareham NJ, Jakes RW, Rennie KL, Mitchell J, Hennings S, Day NE. Validity and repeatability of the EPIC-Norfolk physical activity questionnaire. Int J Epidemiol. 2002;31(1):168–74.
Wareham NJ, Jakes RW, Rennie KL, Schuit J, Mitchell J, Hennings S, et al. Validity and repeatability of a simple index derived from the short physical activity questionnaire used in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Public Health Nutr. 2003;6(4):407–13.
Khaw K-T, Jakes R, Bingham S, Welch A, Luben R, Day N, et al. Work and leisure time physical activity assessed using a simple, pragmatic, validated questionnaire and incident cardiovascular disease and all-cause mortality in men and women: The European Prospective Investigation into Cancer in Norfolk prospective population study. Int J Epidemiol. 2006;35(4):1034–43.
Boekholdt SM, Ron JGP, Nicholas ED, Robert L, Sheila AB, Nicholas JW, et al. Macrophage migration inhibitory factor and the risk of myocardial infarction or death due to coronary artery disease in adults without prior myocardial infarction or stroke: the EPIC-Norfolk prospective population study. Am J Med. 2004;117(6):390–7.
Cox DR. Regression models and life tables. J R Stat Soc (B). 1972;34:187–220.
Steenland K, Henley J, Thun M. All-cause and cause-specific death rates by educational status for two million people in two American Cancer Society cohorts, 1959–1996. Am J Epidemiol. 2002;156(1):11–21.
Bucher HC, Ragland DR. Socioeconomic indicators and mortality from coronary heart disease and cancer: a 22-year follow-up of middle-aged men. Am J Public Health. 1995;85(9):1231–6.
Pocock SJ, Shaper AG, Cook DG, Phillips AN, Walker M. Social class differences in ischaemic heart disease in British men. Lancet. 1987;2(8552):197–201.
Arber S, Ginn J. Gender and inequalities in health in later life. Soc Sci Med. 1993;36(1):33–46.
Arber S, Lahelma E. Inequalities in women’s and men’s ill-health: Britain and Finland compared. Soc Sci Med. 1993;37(8):1055–68.
Martikainen P, Kauppinen TM, Valkonen T. Effects of the characteristics of neighbourhoods and the characteristics of people on cause specific mortality: a register based follow up study of 252,000 men. J Epidemiol Community Health. 2003;57(3):210–7.
Krieger N, Chen J, Selby J. Comparing individual-based and household-based measures of social class to assess class inequalities in women’s health: a methodological study of 684 US women. J Epidemiol Community Health. 1999;53(10):612–23.
Fein O. The influence of social class on health status: American and British research on health inequalities. J Gen Intern Med. 1995;10(10):577–86.
Arber S. Class, paid employment and family roles: Making sense of structural disadvantage, gender and health status. Soc Sci Med. 1991;32(4):425–36.
Gregorio DI, Walsh SJ, Paturzo D. The effects of occupation-based social position on mortality in a large American cohort. Am J Public Health. 1997;87(9):1472–5.
Bopp M, Minder CE. Mortality by education in German speaking Switzerland, 1990–1997: results from the Swiss National Cohort. Int J Epidemiol. 2003;32(3):346–54.
Koskinen S, Martelin T. Why are socioeconomic mortality differences smaller among women than among men? Soc Sci Med. 1994;38(10):1385–96.
Mackenbach JP, Kunst AE, Groenhof F, Borgan JK, Costa G, Faggiano F, et al. Socioeconomic inequalities in mortality among women and among men: an international study. Am J Public Health. 1999;89(12):1800–6.
Manor O, Eisenbach Z, Israeli A, Friedlander Y. Mortality differentials among women: the Israel Longitudinal Mortality Study. Soc Sci Med. 2000;51(8):1175–88.
Stronks K, Van De Mheen H, Van Den Bos J, Mackenbach JP. Smaller socioeconomic inequalities in health among women: the role of employment status. Int J Epidemiol. 1995;24(3):559–68.
Martikainen P, Blomgren J, Valkonen T. Change in the total and independent effects of education and occupational social class on mortality: analyses of all Finnish men and women in the period 1971–2000. J Epidemiol Community Health. 2007;61(6):499–505.
Adler NE, Newman K. Socioeconomic disparities in health: pathways and policies. Health Aff. 2002;21(2):60–76.
Lynch P, Oelman BJ. Mortality from coronary heart disease in the British army compared with the civil population. Br Med J (Clin Res Ed). 1981;283(6288):405–7.
Marmot M, Rose G, Shipley M, Hamilton P. Employment grade and coronary heart disease in British civil servants. J Epidemiol Community Health. 1978;32(4):244–9.
Marmot MG, Smith GD, Stansfeld S, Patel C, North F, Head J, et al. Health inequalities among British civil servants: the Whitehall II study. Lancet. 1991;337(8754):1387–93.
Marmot M, Shipley M, Brunner E, Hemingway H. Relative contribution of early life and adult socioeconomic factors to adult morbidity in the Whitehall II study. J Epidemiol Community Health. 2001;55(5):301–7.
British Heart Foundation. Age-standardised death rates from CHD and stroke by sex and social class, 1976/81 to 1997/99, England and Wales. 2007 [updated 2007; cited 2007 15/10]; Available from: http://www.heartstats.org/temp/Tabsp1.8spweb07.xls.
Kunst AE, Mackenbach JP. Measuring socioeconomic inequalities in health; Copenhagen: World Health Organisation, 1995.
Flegal KM, Brownie C, Haas J. The effects of exposure misclassification on estimates of relative risk. Am J Epidemiol. 1986;123(4):736–51.
Dosemeci M, Wacholder S, Lubin JH. Does nondifferential misclassification of exposure always bias a true effect toward the null value? Am J Epidemiol. 1990;132(4):746–8.
Myint PK, Luben RN, Surtees PG, Wainwright NWJ, Welch AA, Bingham SA, et al. Relation between self-reported physical functional health and chronic disease mortality in men and women in the European Prospective Investigation Into Cancer (EPIC-Norfolk): a prospective population study. Ann Epidemiol. 2006;16(6):492–500.
Wainwright NWJ, Surtees PG. Places, people, and their physical and mental functional health. J Epidemiol Community Health. 2004;58(4):333–9.
Surtees PG, Wainwright NW, Khaw KT. Obesity, confidant support and functional health: cross-sectional evidence from the EPIC-Norfolk cohort. Int J Obes Relat Metab Disord. 2004;28(6):748–58.
Acknowledgments
We thank the participants and general practitioners who took part in the study and the staff of EPIC-Norfolk.
Funding
EPIC-Norfolk is supported by research programme grant funding from the Cancer Research Campaign and Medical Research Council with additional support from the Stroke Association, British Heart Foundation, and Research Into Ageing.
Competing interests
None declared.
Contributors
KTK, SB, and NW are principal investigators in the EPIC-Norfolk population study. SB is responsible for the dietary measurements and analyses. RL is responsible for data management and computing and data linkages for post coding. EM conducted the data analyses and wrote the paper with KTK with contributions from other co-authors.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
McFadden, E., Luben, R., Wareham, N. et al. Occupational social class, risk factors and cardiovascular disease incidence in men and women: a prospective study in the European Prospective Investigation of Cancer and Nutrition in Norfolk (EPIC-Norfolk) cohort. Eur J Epidemiol 23, 449–458 (2008). https://doi.org/10.1007/s10654-008-9262-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10654-008-9262-2