Abstract MP025: Physical Activity and Risk of Coronary Heart Disease in Young Women
Background: The majority of studies on the association between physical activity and coronary heart disease (CHD) risk have been conducted in middle-aged and older populations. Although physical activity has been shown to lower risk of CHD in women by approximately 30%, evidence for the benefits of exercise for CHD in young women is very limited.
Methods and Results: We conducted a prospective cohort study among 114 054 women, 25–42 years of age at baseline, enrolled in the Nurses’ Health Study II and followed from 1989 to 2009. Leisure-time physical activity was assessed at baseline and during follow-up through a series of questions on the specific type of activity and the average time per week spent on the activity over the previous year. Additionally, at baseline, women were asked the number of months per year they participated in strenuous exercise or sports during high school and ages 18–22. During 20 years of follow-up, we documented 518 new cases of non-fatal MI and fatal CHD. After adjusting for age and other cardiovascular risk factors, the rate ratios (RR) (95% confidence intervals [CI]) corresponding to 0, 0.1 – 3.5, 3.6 – 8.8, 8.9 – 21.0, and > 21 MET-hours/week of physical activity were 1.0, 0.93 (0.71, 1.21), 0.73 (0.56, 0.95), 0.67 (0.52, 0.88), and 0.63 (0.49, 0.83) (p for trend = 0.001). There was no evidence of effect modification by age or body mass index. Specifically in women less than 50 years of age, the corresponding RR were 1.0, 0.97 (0.70, 1.35), 0.75 (0.53, 1.04), 0.69 (0.50, 0.96), and 0.63 (0.45, 0.88) (p for trend = 0.008). Brisk walking alone was also associated with significant reductions in CHD risk. In contrast to physical activity during adulthood, frequency of participation in strenuous activity in high school or during ages 18–22 was not associated with risk of CHD when adjusted for current physical activity.
Conclusions: These prospective data suggest that physical activity is associated with substantial risk reductions in the incidence of coronary heart disease in young women.
- © 2012 by American Heart Association, Inc.