Moderate Physical Activity in Healthy Adults Is Associated With Cardiac Remodeling

Abstract

Background: Cardiac mass and volumes are often elevated in athletes, but it is not known whether moderate physical activity is also associated with cardiac dilatation and hypertrophy in a healthy adult population.

Methods and results: In total, 1096 adults (54% female, median age 39 years) without cardiovascular disease or cardiomyopathy-associated genetic variants underwent cardiac magnetic resonance imaging to determine biventricular volumes and function. Physical activity was assessed using a validated activity questionnaire. The relationship between cardiac parameters and activity was assessed using multiple linear regression adjusting for age, sex, race, and systolic blood pressure. Logistic regression was performed to determine the effect of activity on the likelihood of subjects having cardiac dilatation or hypertrophy according to standard cardiac magnetic resonance normal ranges. Increasing physical activity was associated with greater left ventricular (LV) mass (β=0.23; P<0.0001) and elevated LV and right ventricular volumes (LV: β=0.26, P<0.0001; right ventricular: β=0.26, P<0.0001). Physical activity had a larger effect on cardiac parameters than systolic blood pressure (0.06≤β≤0.21) and a similar effect to age (-0.20≤β≤-0.31). Increasing physical activity was a risk factor for meeting imaging criteria for LV hypertrophy (adjusted odds ratio 2.1; P<0.0001), LV dilatation (adjusted odds ratio 2.2; P<0.0001), and right ventricular dilatation (adjusted odds ratio 2.2; P<0.0001).

Conclusions: Exercise-related cardiac remodeling is not confined to athletes, and there is a risk of overdiagnosing cardiac dilatation or hypertrophy in a proportion of active, healthy adults.

Keywords: cardiac magnetic resonance imaging; exercise physiology; left ventricular remodeling; remodeling; right ventricle.

Figure 1.

A short-axis cine image demonstrating the assessment of biventricular volumes and function in a healthy adult (right ventricular cavity in purple, left ventricular cavity in orange, and myocardium in yellow with epicardial contours defining the left and right ventricles).

Figure 2.

A–C, Tukey box and whisker plots showing the relationship between activity level on the Copenhagen scale and indexed (A) LV mass, (B) LVEDV, and (C) RVEDV. The jittered dots show data for each subject (n=1096), with blue points indicating a value within the normal range and red points those above the normal range for that individual according to published reference ranges stratified by decade of age and sex.^, Pair wise comparisons with a Bonferroni-corrected P value <0.05 are indicated by horizontal lines. EDV indicates end diastolic volume; LV, left ventricular; and RV, right ventricular.

Figure 3.

Bar chart showing percentage of subjects classed as having LV hypertrophy, LV dilatation, or RV dilatation grouped by activity level on the Copenhagen scale (ie, a LVMi, LVEDVi, or RVEDVi above the normal range for that individual according to published reference ranges stratified by decade of age and sex^,). For LV hypertrophy, χ²(3)=39.1, P<0.0001; for LV dilatation, χ²(3)=55.2, P<0.0001; for RV dilatation, χ²(3)=89.4, P<0.0001. EDVi indicates indexed end-diastolic volume; LV, left ventricular; LVMi, indexed LV mass; and RV, right ventricular.