Physical Activity Can Lower Risk of Heart Damage, Says New Study

Apr 25, 2017 by News Staff / Source

According to a new study, physical activity can lower the risk of myocardial damage in middle-aged and older adults and reduce the levels of myocardial damage in people who are obese.

                 Physical activity is inversely associated with chronic subclinical myocardial damage, according to a study by Florido et al. Image credit: Skeeze.

“Physical activity is associated with reduced risk of heart failure, particularly among obese people,” the team behind the study said.
“Heart failure may be caused by subclinical myocardial damage, in which there is damage to the heart muscle but a patient does not show sign or symptoms.”
The scientists studied 9,427 participants aged 45-64 years without cardiovascular disease and a body mass index of more than 18.5 kg/m2.
Physical activity was categorized per American Heart Association guidelines as ‘recommended’ (at least 75 min/week of vigorous intensity or at least 150 min/week of a combination of moderate to vigorous intensity), ‘intermediate’ (1-74 min/week of vigorous intensity or 1-149 min of a combination of moderate to vigorous intensity), or ‘poor’ (no moderate to vigorous exercise).
                To measure damage to the heart, the authors assessed levels of high-sensitivity cardiac troponin T (hs-cTnT). Elevated levels of this myofibrillar protein are considered a marker of heart damage and have been shown to be associated with future heart failure.
Elevated levels of hs-cTnT were observed in 7.2% of the total study population.
Individuals with lower levels of physical activity were significantly more likely to have elevated levels of this biomarker suggesting higher heart damage.
For example, participants who performed poor and intermediate levels of physical activity were 39% and 34% more likely to have heart damage than persons who engaged in recommended levels of physical activity.
               The researchers subsequently looked at the combined associations of physical activity and obesity with this blood marker of heart damage.
“Obesity had been previously shown to be strongly associated with elevated levels of hs-cTnT, and the combination of obesity and elevated hs-cTnT was associated with a significantly increased risk of future heart failure,” the authors said.
In this work, they demonstrated that participants with obesity who performed poor levels of exercise had the highest likelihood of having elevated hs-cTnT levels.
Participants with obesity who performed recommended levels of physical activity had a weaker association with elevated levels of hs-cTnT, and after adjustment for traditional cardiac risk factors, this was association was no longer statistically significant.
              These results suggest physical activity may lessen the association of obesity and heart damage.
The authors also found a significant interaction between physical activity and obesity on elevated levels of hs-cTnT, which indicates that the protective association of physical activity and heart damage may be stronger among individuals with obesity, a group at particularly high risk for future heart failure.
“The protective association of physical activity against subclinical myocardial damage may have implication for heart failure risk reduction, particularly among the high-risk group of individuals with excess weight,” said Dr. Roberta Florido, cardiology fellow at Johns Hopkins Hospital and lead author of the study.
“Promoting physical activity may be a particularly important strategy for heart failure risk reductions among high risk groups such as those with obesity.”
The findings were published in the online edition of the JACC: Heart Failure on April 24, 2017.
_____
Roberta Florido et al. 2017. Physical Activity, Obesity, and Subclinical Myocardial Damage. JACC: Heart Failure 5 (5): 377-384; doi: 10.1016/j.jchf.2017.02.002