Research News

Lack of exercise outweighs obesity among heart disease risk factors, says Australian study

BMJ 2014; 348 doi: https://doi.org/10.1136/bmj.g3182 (Published 09 May 2014) Cite this as: BMJ 2014;348:g3182
  1. Jacqui Wise
  1. 1London

Lack of exercise affects a woman’s risk of developing heart disease more than other known risk factors, including being overweight, new research has shown.1

Australian researchers writing in the British Journal of Sports Medicine said that greater effort was needed to promote exercise among women.

The study calculated the population attributable risk of heart disease for four known risk factors: high body mass index, smoking, high blood pressure, and physical inactivity. The population attributable risk is a mathematical formula for defining the proportion of disease in a population that would disappear if exposure to a specific risk factor were eliminated.

To calculate this the researchers used relative risk data from the Global Burden of Disease study combined with estimates of the prevalence of these four risk factors among 32 154 participants in the Australian Longitudinal Study on Women’s Health—a prospective study that, since 1996, has been tracking the long term health of women born in 1921-26, 1946-51, and 1973-78.

They found that relative risks and prevalence estimates varied across the adult lifespan. In young women aged up to 30 the highest population risk was attributed to smoking, with a population attributable risk of 59%; but this decreased markedly with age, falling to 5% at age 70-75. At every age from the early 30s to the late 80s the population attributable risk was highest for physical inactivity: 48% in the young cohort, 33% in the middle cohort, and 24% in the older cohort.

The researchers noted that because only 64 deaths from ischaemic heart disease occurred among young Australian women each year the results did not imply that smoking caused more heart disease in young women, but that smoking was comparatively more important at a young age than the other risk factors. The risk attributable to smoking declined rapidly with age, as many women stop smoking when they become mothers.

The researchers said that continuing efforts to stop smoking among young people were warranted but that physical inactivity was a “Cinderella” risk factor, as obesity received much more attention in Australia.

They concluded, “Our data suggest that national programmes for the promotion and maintenance of physical activity, across the adult lifespan, but especially in young adulthood, deserve to be a much higher public health priority for women than they are now.”

Notes

Cite this as: BMJ 2014;348:g3182

References

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