"Engaging in exercise is beneficial for lowering the risk of having a heart attack in young women. Exercise did not have to be strenuous to be beneficial; moderate-intensity physical activity, including brisk walking, was associated with lower risk of heart disease," Dr Andrea K Chomistek (Indiana University Bloomington School of Public Health) told heartwire from Medscape by email.
Researchers led by Chomistek conducted a prospective analysis of data on 97,230 women participating in the Nurses' Health Study II, who were 27 to 44 years old at baseline in 1991. They assessed leisure-time physical activity biennially through questionnaires filled out by the participants and used Cox proportional-hazards analysis to study associations between CHD risk and frequency, type, and volume of physical activity.
During 20 years of follow-up, the researchers observed 544 incident CHD cases. They found the hazard ratio to be 0.75 (P=0.01) when comparing 30 or more with less than 1 metabolic equivalent of task-hours (MET) per week of physical activity.
Women reporting 15 or more METs of moderate-intensity physical activity a week had a 33% lower risk of CHD compared with women reporting no physical activity (HR 0.67, P=0.01). Women reporting 15 or more METs of vigorous activity a week had a 23% lower risk of CHD.
When they repeated the analysis at 2 and 4 years lag, they found that the total leisure-time activity and moderate-activity results were no longer statistically significant, but the vigorous-activity results remained significant.
They also found that aerobics, outdoor work, and brisk walking were each significantly associated with lower risk of CHD (P=0.04, 0.04, and 0.001, respectively). Brisk walking for 2.5 or more hours per week resulted in a 35% risk reduction for CHD compared with women who reported no walking.
They did not find a statistically significant association between physical activity and body mass index and risk reduction.
"It is important for everyone to be active. In particular, for patients who are inactive, physicians should emphasize that they don't need to run a marathon or join a gym to lower their risk of having a heart attack—walking alone is beneficial," Chomistek said. "I was not surprised by this result because the benefit of walking has been shown previously in middle-aged and older adults as well. Walking is a great form of exercise.
"With regard to physical activity, every little bit counts. It doesn't matter if the exercise is vigorous or moderate or if you do it 6 days a week or 3. . . . It's just important to be active," she concluded.
Dr Erin D Michos (Johns Hopkins School of Medicine, Baltimore, MD), coauthor of an accompanying editorial, told heartwire by email, "The marked decline in the death rates of cardiovascular diseases since the 1970s is a tremendous public-health success story. However, more recent data published just last month in JAMA Cardiology has shown that since 2011 that this decline is slowing down."
"Notably, for young women under the age of 55, while the absolute CVD mortality rate is still relatively low, the rate has been stagnant and not declining as [the rate] has been for older adults," she said.
"Younger women <55 years of age may be a neglected demographic group as a target of CVD prevention efforts due to their lower perceived risk. I think we as healthcare providers spend a lot of our preventive efforts focusing on older adults who are at higher cardiovascular risk in general," Michos continued.
She offered suggestions: "We think that future preventive efforts should actually focus on a 'family-centered' approach, rather than solely an individualized-approach. Possible suggestions include taking advantage of the widespread use of mobile technology to utilize text prompts of fitness reminders and diet/fitness apps to help track, motivate, and prompt lifestyle changes. We also recommend involving women's larger global social networks and community-based interventions."
The National Institutes of Health supported this research. The authors reported no relevant financial relationships.
Heartwire from Medscape © 2016 Medscape, LLC
Cite this: Leisure-time Physical Activity Decreases Risk of Cardiovascular Disease in Younger Women - Medscape - Jul 26, 2016.