Purpose: We assessed the effects of the four newly defined American Heart Association (AHA) lifestyle factors on mortality by examining the associated population attributable fractions (PAFs) of these factors.
Methods: Slightly modified AHA cardiovascular health factors (smoking, BMI, cardiorespiratory fitness, and diet) were measured among 11,240 (24% women) participants from the Aerobics Center Longitudinal Study between 1987 and 1999. The cohort was followed to December 31, 2003 or death. PAFs were calculated as the proportionate reduction in death attributable to identified risk factors.
Results: During an average 12 years of follow-up, 268 deaths occurred. Low fitness had the highest PAFs at the 5th, 10th, and 15th year of follow-up, respectively: 6.6%, 6.4%, and 5.5%. Current smokers had the second highest PAFs at the 5th, 10th, and 15th year of follow-up, respectively: 5.4%, 5.2%, and 5.0%. Additional adjusting for other confounders in the model did not change the above associations. The PAFs for overweight or obesity and unhealthy diet were not significant in the current analyses.
Conclusions: Assuming a causal relationship between smoking, low fitness and mortality, avoidance of both would have prevented 13% of the deaths in the current population. Preventive interventions to increase physical activity and stop smoking would most likely promote longevity.