The impact of obesity on left ventricular mass and left ventricular systolic function in children

Abstract

Background Obesity causes cardiovascular disturbances. The incidence of cardiovascular disease is higher even in mildly obese patients than in lean subjects. Objectives The purpose of this study was to compare left ven- tricular (LV) mass, LV internal dimensions, and LV systolic func- tion between obese and normal children; and to determine the as- sociation of the degree of obesity with LV mass and LV systolic function. Methods This cross-sectional study was conducted on elemen- tary school students in Jakarta from February to April 2003. We measured the subjects’ body weight and height, and performed lipid profile and echocardiography examinations. Measurements of LV mass, LV internal dimensions with regard to septum thick- ness, LV internal diameter, and LV posterior wall thickness; and LV systolic function as indicated by shortening fraction and ejec- tion fraction, were performed echocardiographically. The differ- ences in measurements between obese and normal children as well as between obese children with and without lipid abnormality were analyzed. The correlation between the degree of obesity with LV size and systolic function was determined. Results Twenty-eight normal children and 62 obese children were enrolled in the study. Mean LV mass was 35.7 (SD 5.16) g/cm 3 in obese children versus 24.0 (SD 3.80) g/cm 3 in normal children (P<0.0001). Mean septum thickness was 0.8 (SD 0.14) mm in obese children versus 0.6 (SD 7.90) mm in normal children (P< 0.0001). Mean posterior wall thickness was 0.9 (SD 0.14) mm in obese children versus 0.6 (SD 9.97) mm in normal children (P<0.0001). Mean LV internal diameter was 4.0 (SD 0.34) mm in obese children versus 3.9 (SD 0.29) mm in normal children (P=0.300). There was strong correlation between the degree of obesity and LV mass (r=0.838, P<0.0001). LV systolic function (shortening fraction) was 37.1 (SD 4.20) percent in obese children versus 35.8 (SD 4.99) percent in normal children (P=0.19). Ejec- tion fraction was 67.4 (SD 5.32) percent in obese children versus 65.5 (SD 6.29) percent in normal children (P=0.13). There was weak correlation between LV systolic function and the degree of obesity (shortening fraction r=0.219, P=0.038; ejection fraction r=0.239, P=0.023). Conclusions Obese children had significantly greater LV mass, septum thickness, and posterior wall thickness than normal chil- Background dren. Such significant difference was absent for LV internal diam- eter and measures of LV systolic function. There was no signifi- cant difference in LV mass and LV systolic function between obese children with or without abnormality of lipid profile. A strong corre- lation exists between the degree of obesity and LV mass, but the correlation between degree of obesity and LV systolic function was weak

Keywords

• childhood obesity
• left ventricular mass
• left ventricular systolic function