The AHA also classifies physical inactivity as a major risk factor. The extent to which physical inactivity raises coronary risk independently of the major risk factors is uncertain. Certainly, physical inactivity has an adverse effect on several known risk factors. Even though physical inactivity is an independent risk factor, physical activity levels are difficult to reliably measure in individual patients. For these reasons, physical inactivity is not included in quantitative risk assessment.
Physical inactivity constitutes an independent target for intervention.
Physicians should encourage all of their patients to engage in an appropriate exercise regimen, and high-risk patients should be referred for professional guidance in exercise training. There is little doubt that a positive family history of premature CHD imparts incremental risk at any level of risk factors. This association has been shown by the Framingham Heart Study. Nonetheless, the degree of independence from other risk factors and the absolute magnitude of incremental risk remain uncertain. For this reason, Framingham investigators did not include family history among the major independent risk factors.