Life expectancy in relation to cardiovascular risk factors: 38 year follow-up of 19 000 men in the Whitehall study
BMJ 2009; 339 doi: https://doi.org/10.1136/bmj.b3513 (Published 17 September 2009) Cite this as: BMJ 2009;339:b3513
- Robert Clarke, reader in epidemiology and public health medicine1,
- Jonathan Emberson, senior statistician1,
- Astrid Fletcher, professor of epidemiology2,
- Elizabeth Breeze, lecturer in epidemiology3,
- Michael Marmot, professor of epidemiology and public health medicine3,
- Martin J Shipley, senior lecturer in medical statistics3
- 1Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), Richard Doll Building, University of Oxford, Oxford OX3 7LF
- 2London School of Hygiene and Tropical Medicine, London WCIE 6HT
- 3Department of Epidemiology and Public Health, University College London Medical School, London WCIE 6BT
- Correspondence to: R Clarke robert.clarke{at}ctsu.ox.ac.uk
- Accepted 9 June 2009
Abstract
Objective To assess life expectancy in relation to cardiovascular risk factors recorded in middle age.
Design Prospective cohort study.
Setting Men employed in the civil service in London, England.
Participants 18 863 men examined at entry in 1967-70 and followed for 38 years, of whom 13 501 died and 4811 were re-examined in 1997.
Main outcome measures Life expectancy estimated in relation to fifths and dichotomous categories of risk factors (smoking, “low” or “high” blood pressure (≥140 mm Hg), and “low” or “high” cholesterol (≥5 mmol/l)), and a risk score from these risk factors.
Results At entry, 42% of the men were current smokers, 39% had high blood pressure, and 51% had high cholesterol. At the re-examination, about two thirds of the previously “current” smokers had quit smoking shortly after entry and the mean differences in levels of those with high and low levels of blood pressure and cholesterol were attenuated by two thirds. Compared with men without any baseline risk factors, the presence of all three risk factors at entry was associated with a 10 year shorter life expectancy from age 50 (23.7 v 33.3 years). Compared with men in the lowest 5% of a risk score based on smoking, diabetes, employment grade, and continuous levels of blood pressure, cholesterol concentration, and body mass index (BMI), men in the highest 5% had a 15 year shorter life expectancy from age 50 (20.2 v 35.4 years).
Conclusion Despite substantial changes in these risk factors over time, baseline differences in risk factors were associated with 10 to 15 year shorter life expectancy from age 50.
Footnotes
We thank Jill Boreham for producing the figure using data from the WHO mortality statistics for the UK and Richard Peto, Gary Whitlock, and Dave Leon for helpful comments on the text.
Contributors: AF and MM supervised the study. RC coordinated the re-survey of surviving participants in Oxford. EB prepared the data for analysis. MJS carried out the statistical analysis of mortality in relation to the baseline data. JE carried out the statistical analysis of the re-survey data. RC and MJS drafted the report with contributions from all the authors. RC and MJS are guarantors.
Funding: The Whitehall study was supported by the British Heart Foundation and Medical Research Council. JE and MJS are supported by the British Heart Foundation and MM by a MRC research professorship. All of the analyses were carried out independently of the sources of support.
Competing interests: None declared.
Ethical approval: Both the original survey and this study were approved by the ethics committees of the participating institutions. Participants provided consent to take part in the original survey in 1967-70. Surviving participants provided written consent to take part in the re-survey of survivors in 1997.
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