Left ventricular mass normalization in child and adolescent athletes must account for sex differences.

Hubert Krysztofiak,Andrzej Folga,Łukasz A Małek,Marcel Młyńczak,Wojciech Braksator,Daniel M Johnson

doi:10.1371/journal.pone.0236632

Abstract

To assess left ventricular hypertrophy, actual left ventricular mass (LVM) normalized for body size has to be compared to the LVM normative data. However, only some published normative echocardiographic data have been produced separately for girls and boys; numerous normative data for the pediatric population are not sex-specific. Thus, this study aimed to assess whether the LVM normative data should be developed separately for girls and boys practicing sports. Left ventricular mass was computed for 331 girls and 490 boys, 5-19 years old, based on echocardiography. The effect of sex on the relationship between LVM and body size was evaluated using a linear regression model. Seven sets of the LVM normative data were developed, using different methodologies, to test concordance between sex-specific and non-specific normative data. Every set consisted of normative data that was sex-specific and non-specific. Upon these normative data, for every study participant, seven pairs of LVM z-scores were calculated based on her/his actual LVM. Each pair consisted of z-scores computed based on sex-specific and non-specific normative data from the same set. The regression lines fitted to the data points corresponding to LVM of boys had a higher slope than of girls, indicating that sex affects the relationship between LVM and body size. The mean differences between the paired LVM z-scores differed significantly from 0. The percentage of discordant indications, depending on the normalization method, ranged from 66.7% to 100% in girls and from 35.4% to 50% in boys. Application of the LVM normative data that were not sex-specific made relative LVM underestimated in girls and overestimated in boys. The LVM normative data should be developed separately for girls and boys practicing sports. Application of normative data that are not sex-specific results in an underestimation of relative LVM in girls and overestimation in boys.

Highlights

Echocardiography is recommended as a first-line diagnostic tool for cardiac size evaluation in both children and adults [1,2,3]
The regression lines fitted to the data points corresponding to left ventricular mass (LVM) of boys had a higher slope than of girls, indicating that sex affects the relationship between LVM and body size
Girls LMV indexed to body surface area (BSA) LVM indexed to height2.7 LVM indexed to BSAb LVM indexed to heightbs Boys LMV indexed to BSA LVM indexed to height2.7 LVM indexed to BSAb LVM indexed to heightbs Combined groups LMV indexed to BSA LVM indexed to height2.7 LVM indexed to BSAb LVM indexed to heightbs

Summary

Introduction

Echocardiography is recommended as a first-line diagnostic tool for cardiac size evaluation in both children and adults [1,2,3]. Direct measurements of left ventricular muscle and chamber dimensions and further computation of left ventricular mass (LVM), provide the basis to diagnose hypertrophy [2,4]. The presence of left ventricular hypertrophy (LVH) is associated with increased risk for adverse cardiovascular (CV) outcomes [5,6]. Exercise is considered as a strong counter-measure against cardiovascular disease (CVD) [10,11,12,13], athletes and physically active people are not CV disease-immune population. To assess left ventricular hypertrophy, actual left ventricular mass (LVM) normalized for body size has to be compared to the LVM normative data. This study aimed to assess whether the LVM normative data should be developed separately for girls and boys practicing sports

Objectives

Methods

Results

Conclusion