It is known that factors including obesity, smoking and high blood pressure increase the risk of heart disease in women, however a new study suggests that physical activity from the age of 30 has the biggest impact.
For this latest study, the researchers wanted to compare estimates of the main four risk factors of heart disease, namely, high body mass index (BMI), smoking, high blood pressure and physical inactivity. The study notes that these factors are responsible for over half the global prevalence of heart disease, the leading cause of death across high income countries.
The researchers used data on 32,254 participants in the Australian Longitudinal Study on Women's Health, which tracks the long-term health of women born in certain spans of time between 1921 and 1978. They then employed a mathematical formula used to assess the proportion of disease in a specific population that would vanish if exposure to a certain risk factor were removed. Data from the Global Burden of Disease study were also used and applied to the Australian women who took part in the study.
The investigators observed that smoking prevalence fell from 28% in women 22-27 years old to 5% in those between the ages of 73 and 78.
However, inactivity prevalence and high blood pressure increased across their lifespans, from age 22 to 90, and overweight prevalence increased between the ages of 22 and 64, declining after those ages.
The team then combined prevalence with relative risk data, which reveals the likelihood that a woman with a specific risk factor will develop heart disease, compared with a woman without that risk factor.
After combining this data, the researchers observed that, until the age of 30, smoking had the greatest influence on heart disease risk.
Between the ages of 30 and 90, however, it was found that low physical activity levels had the greatest effect on higher levels of population risk, compared with any of the other risk factors.
The World Health Organisation (WHO) recommend that all adults get 150 minutes of moderate intensity physical activity each week, and the researchers say if every woman between 30 and 90 were to reach this recommendation, large numbers of lives would be saved.
Based on their results, the researchers say the effect of different risk factors on chances of developing heart disease change throughout a woman's life. The report adds:
"Our data suggest that national programs 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."
The study was published in the British Journal of Sports Medicine.
