Mon, Sept 19 at noon:
Paradox of Unintended Pregnancy, Jennifer Barber
Turkbey, E.B., N.W. Jorgensen, W.C. Johnson, A.G. Bertoni, J.F. Polak, Ana Diez Roux, R.P. Tracy, J.A. Lima, and D.A. Bluemke. 2010. "Physical activity and physiological cardiac remodelling in a community setting: the Multi-Ethnic Study of Atherosclerosis (MESA)." Heart, 96(1): 42-48.
Objective: To evaluate the association of physical activity with left ventricular structure and function in the general population in a community setting. Design: Cross-sectional study. Setting: The Multi-Ethnic Study of Atherosclerosis (MESA), a population-based study of subclinical atherosclerosis. Participants: A multiethnic sample of 4992 participants (aged 45-84 years; 52% female) free of clinically apparent cardiovascular disease. Interventions: Physical activity induces beneficial physiological cardiac remodelling in a cross-sectional study of non-athlete individuals. Main Outcome Measures: Left ventricular mass, volumes and function were assessed by cardiac magnetic resonance imaging. Physical activity, defined as intentional exercise and total moderate and vigorous physical activity, was assessed by a standard semiquantitative questionnaire. Results: Left ventricular mass and end-diastolic volume were positively associated with physical activity (eg, 1.4 g/m(2) (women) and 3.1 g/m(2) (men) greater left ventricular mass in the highest category of intentional exercise compared with individuals reporting no intentional exercise; p = 0.05 and p < 0.001, respectively). Relationships were non-linear, with stronger positive associations at lower levels of physical activity (test for non-linearity; p = 0.02 and p = 0.03, respectively). Cardiac output and ejection fraction were unchanged with increased physical activity levels. Resting heart rate was lower in women and men with higher physical activity levels (eg, -2.6 beats/minute lower resting heart rate in the highest category of intentional exercise compared with individuals reporting no intentional exercise; p < 0.001). Conclusions: In a community-based population free of clinically apparent cardiovascular disease, higher physical activity levels were associated with proportionally greater left ventricular mass and end-diastolic volume and lower resting heart rate.
Country of focus: United States of America.