Exercise and heart health

 

A chara, – A front-page article (September 21st), reported findings from a Korean study published in the journal, Heart.

The article stated that “exercise could increase heart attack risk”. In our opinion, this is an entirely incorrect interpretation of the study and the assertion is in no way supported by the evidence presented in the paper referred to.

First, the risk of heart attack was not investigated in the study. In fact, it is one of its central limitations and is clearly acknowledged as such by the authors.

Second, what the article does show, is that there appeared to be a higher rate of calcium deposition in the heart arteries of patients who exercise more.

While this is an interesting finding, it may be misleading: as calcium deposition increases with age, it might simply reflect the fact that patients in the study who were active were marginally older (and tended to have higher blood pressure) than the patients who were inactive.

Third, even if the association were true, and not due to confounding factors such as age or blood pressure differences between the groups, this increase in calcium deposition might represent a positive phenomenon, related to improved healing and stabilisation of cholesterol deposits in the heart arteries.

In fact, this is explicitly stated by the authors as one of the conclusions in the final line of the study.

Finally, independent of the academic question examined in the Korean study, the authors are at pains to point out that the heart disease-related benefits of physical activity are unquestionable.

Current expert guidelines in Europe and the US recommend at least 150 minutes of moderate intensity exercise per week (eg, brisk walking, light jogging) or at least 75 minutes of vigorous intensity exercise per week (eg, jogging, running) in order to prevent heart disease.

It is most important that this message is not lost in translation.

– Is mise,

Is mise,

Prof ROBERT BYRNE,

Professor of Cardiovascular Research, RCSI, Director of Cardiology and Director of Cardiovascular Research Institute (CVRI) Dublin, Mater Private Network

Dr RÓISÍN COLLERAN,

Honorary Senior Lecturer, RCSI, Consultant Cardiologist, Mater Private Network

Dr HIMANSHU RAI

Honorary Senior Lecturer, RCSI, Director of Cardiovascular Imaging Core Laboratory, CVRI Dublin, Mater Private Network