A new study has become the first to uncover a link between a history of asthma and an increased likelihood of left ventricular hypertrophy, a risk factor for heart failure.
Now, the new research - recently published in the journal JACC: Heart Failure - suggests that people who have a history of asthma may also be at greater risk of left ventricular hypertrophy (LVH).
LVH is a condition characterized by the thickening and enlargement of the left ventricle, which is the heart chamber responsible for pumping oxygen-rich blood around the body.
Many patients with LVH do not experience any signs or symptoms, particularly in the early stages. When symptoms do arise, they may include shortness of breath, chest pain, fatigue, heart palpitations, and dizziness or fainting.
Higher LVM with history of asthma
For the new study, senior author Dr. Lu Qi, of the Tulane University Obesity Research Center in New Orleans, LA, and colleagues assessed the health data of 1,118 adults who were part of the Bogalusa Heart Study.
All adults had completed questionnaires detailing their history of asthma from childhood. Subjects were followed up for around 10 years.
At two to four time points during follow-up, participants' left ventricular mass (LVM) - that is, the size of the left ventricle - was assessed using echocardiography. The researchers accounted for the body size of participants by indexing their LVM for height, providing them with a left ventricular mass index (LVMI).
Compared with adults who did not have a history of asthma, those who did have a history of the respiratory condition were found to have a higher adjusted mean LVM, as well as a higher LVMI.
The link between asthma history and greater LVM and LVMI was stronger among participants who had higher systolic blood pressure, the team reports.
The findings remained after accounting for other key risk factors for CVD, including age, smoking status, heart rate, and use of blood pressure medication.
Commenting on the what the results indicate, the researchers say:
"Our data suggest that aggressive lifestyle modifications or even pharmacological treatment may be applied to people with a history of asthma, especially those also affected by high blood pressure, to lower CV [cardiovascular] risk."
"Further studies are warranted to verify our findings in other cohorts," the team adds.
More research needed
While the team's findings raise further questions about how asthma history affects heart health, Dr. John S. Gottdiener, of the University of Maryland School of Medicine in Baltimore, notes that a lack of baseline echocardiography is a major limitation of the study.
"All we know is the difference in left ventricular mass between those who did and did not have a diagnosis of asthma years before echocardiography was performed," he writes in an editorial linked to the research.
"We look forward to further studies which will accurately determine the association of asthma with death, heart failure, myocardial infarction, and stroke," adds Dr. Gottdiener.
"Of particular value will be learning how severe and long the asthmatic exposure needs to be to pose significant risk. This together with determining potential pathophysiologic mechanisms will help to intelligently design effective prevention interventions validated by randomized controlled trials."