Dose Response Between Physical Activity and Risk of Coronary Heart Disease: A Meta-Analysis

Study Questions:

What amount of physical activity is required to lower risk of coronary heart disease (CHD) when assessing the dose response?

Methods:

An aggregate data meta-analysis was conducted of epidemiological studies investigating physical activity and primary prevention of CHD. After reviewing 3,194 abstracts, the authors included 33 prospective cohort studies published in English since 1995. A random-effects generalized least squares spline model was used for trend estimation to derive pooled dose-response estimates.

Results:

Among the 33 studies, nine allowed quantitative estimates of leisure-time physical activity. Individuals who engaged in the equivalent of 150 minutes/week of moderate-intensity leisure-time physical activity had 14% lower CHD events (relative risk [RR], 0.86; 95% confidence interval [CI], 0.77-0.96) compared with those reporting no leisure-time physical activity. Those engaging in the equivalent of 300 minutes/week of moderate-intensity leisure-time physical activity (2008 US federal guidelines for additional benefits) had a 20% (RR, 0.80; 95% CI, 0.74-0.88) lower risk. At higher levels of physical activity, RRs were modestly lower. People who were physically active at levels lower than the minimum recommended amount also had significantly lower risk of CHD. There was a significant interaction by sex (p = 0.03); the association was stronger among women than men. There was an added benefit of high- versus low-intensity physical activity (RR of 0.75 for CHD).

Conclusions:

The findings provide quantitative data supporting US physical activity guidelines, which stipulate that “some physical activity is better than none” and “additional benefits occur with more physical activity.”

Perspective:

This excellent meta-analysis speaks for itself. The only weakness is the inability to have a uniform definition for CHD between studies.

Clinical Topics: Prevention

Keywords: Risk, Leisure Activities, Motor Activity, Coronary Disease, Primary Prevention


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