Introduction:
Although cigarette smoking, physical inactivity, obesity, and poor diet each have been linked to the risk of premature death, little is known about their relative individual and combined impact, adapted from the American Heart Association (AHA)’s new cardiovascular health construct, on mortality outcomes. We hypothesized that the individual and the combined health behaviors were inversely associated with all-cause mortality. The purpose of the study is to estimate the mortality effects of the 4 AHA defined cardiovascular health behaviors by examining the associated population attributable fractions (PAFs) of individual and combination factors.
Methods:
The study included 11240 (24% women) participants from the Aerobics Center Longitudinal Study (ACLS). Slightly modified AHA cardiovascular health behaviors (smoking, BMI, cardiorespiratory fitness and diet) were collected between 1987 and 1999 as part of the clinical examination. We used cardiorespiratory fitness as an objective marker of recent physical activity habits. Individuals with a history of a cardiovascular disease, or cancer were excluded. The cohort was followed to December 2003 or death. PAFs were calculated after adjusting for age, gender, hypertension, diabetes, hypercholesterolemia, family history of CVD, and the four health behaviors.
Results:
Two hundred and sixty-eight deaths were documented during an average 12 years of follow-up. Low fitness had the highest PAFs at the 5
th
, 10
th
, and 15
th
year of follow-up, respectively: 6.6% (95% CI: 1.6% - 11.4%), 6.4% (95% CI: 1.5% - 11.0%), and 5.5% (95% CI: 1.3% - 9.6%). Current smokers had the second highest PAFs at the 5
th
, 10
th
, and 15
th
year of follow-up, respectively: 5.4% (95% CI: 0.1% - 10.3%), 5.2% (95% CI: 0.1% - 9.9%), and 5.0% (95% CI: 0.2% - 9.5%). Additional adjustment for other confounders in the model did not change the above associations. The PAFs for overweight or obese and unhealthy diet were not significant in the current study.
Conclusion:
Assuming a causal relationship between smoking, low fitness and mortality, avoidance of these two cardiovascular health risk factors would have prevented 13% of the deaths in the ACLS population. Targeted interventions to increase fitness as well as stopping smoking would most likely promote longevity.
Ideal Cardiovascular Health and Mortality: Aerobics Center Longitudinal Study
