Fitness in Young Adults and Cardiovascular Risk

Study Questions:

Is cardiorespiratory fitness in early adulthood associated with long-term risk of cardiovascular disease (CVD)?

Methods:

Data from the CARDIA (Coronary Artery Risk Development in Young Adults) study, a prospective study of US adults, ages 18-30 years, were used for the present analysis. A total of 4,872 participants who completed treadmill exercise testing at baseline (March 1985 through June 1983) and 2,472 adults who completed a second treadmill test 7 years later were followed for a median of 26.9 years. Follow-up was complete in August 2011. The primary outcome of interest was coronary artery calcium (CAC) assessed at years 15 (2000-2001), 20 (2005-2006), and 25 (2010-2011), and left ventricular mass assessed at years 5 (1990-1991) and 25 (with global longitudinal strain). Incident CVD and all-cause mortality were additional adjudicated outcomes.

Results:

Among the 4,872 adults who had a baseline treadmill test, 273 (5.6%) died and 193 (4.0%) experienced CVD events during follow-up. After adjustment for multiple factors, each additional minute of exercise test duration (at baseline) was associated with a 15% lower hazard of death (hazard ratio [HR], 0.85; 95% confidence interval [CI], 0.80-0.91; p < 0.001) and a 12% lower hazard of CVD (HR, 0.88; 95% CI, 0.81-0.96; p = 0.002). Higher levels of baseline cardiorespiratory fitness were associated with significantly lower left ventricular mass index (p = 0.02) and significantly better global longitudinal strain (p < 0.001) at year 25. A 1-minute reduction in fitness by year 7 was associated with 21% and 20% increased hazards of death (HR, 1.21; 95% CI, 1.07-1.37; p = 0.002) and CVD (HR, 1.20; 95% CI, 1.06-1.37; p = 0.006), respectively. Fitness and change in fitness was not associated with CAC.

Conclusions:

The investigators concluded that higher levels of fitness at baseline and improvement in fitness early in adulthood are favorably associated with lower risks for CVD and mortality. Fitness and changes in fitness are associated with myocardial hypertrophy and dysfunction, but not CAC.

Perspective:

These data support the need for routine exercise counseling by providers, starting at a young age. Efforts to support exercise in the workplace and community make sense from a public health perspective.

Keywords: Cardiovascular Diseases, Exercise, Exercise Test, Hypertrophy, Left Ventricular, Primary Prevention, Risk Factors, Vascular Calcification, Ventricular Dysfunction, Left, Young Adult


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