Influence of obesity and insulin resistance on left atrial size in children.
BACKGROUND
Left atrial (LA) enlargement has been linked to obesity and insulin resistance in adults.


OBJECTIVE
The purpose of this study was to determine the association in children between LA area and: (i) different components of the metabolic syndrome including obesity (OB), measures of body mass index (BMI) and waist circumference (WC), homeostasis model assessment-insulin resistance (HOMA-IR, proinsulin), and blood pressure (BP); and (ii) left ventricular mass (LVM) and diastolic function, measured using echo Doppler.


RESULTS
Eighty-four (44 females) subjects, [40 OB (BMI>95%), 28 overweight (BMI>85%)], 16 non-OB (BMI<85%)] aged 9+/-2.24 yrs were matched for sex and age. BMI, WC, BP, Tanner stage, and Mode M, 2-dimensional and Doppler transmitral echocardiography were assessed. A standard oral glucose tolerance test (OGTT) was done, measuring glucose, insulin, and proinsulin concentrations. Hypertension was only present in OB subjects (25%). Significant univariate association (p<0.001) was found between LA area and height (r=0.52), age (r=0.45), Tanner stage (r=0.45), BMI (r=0.66), WC (r=0.70), systolic BP (r=0.52), diastolic BP (r=0.53), proinsulin (r=0.36), and HOMA-IR (r=0.36). In the multivariate regression analysis, independent variables were entered in a stepwise fashion: initially, gender (p=0.006) and Tanner stage (p=0.011) were still significant independent correlates of LA area after adjusting for age, gender, and Tanner stage. Subsequently, incorporation of WC showed that WC (p=0.018) was a significant independent correlate of LA area. A larger model constructed to test the significance of adjustment factors, including WC, BP, LVM, and HOMA-IR showed that WC (p<0.001) was the only significant independent variable.


CONCLUSIONS
LA enlargement is present in childhood and is related to abdominal OB and insulin resistance, suggesting that children with central OB are at increased risk for cardiovascular disease.
Hirschler
Valeria
V
Department of Nutrition and Diabetes of Durand Hospital, Buenos Aires, Argentina. vhirschler@intramed.net.ar
Acebo
H Laura Perez
HL
Fernandez
Graciela B
GB
de Luján Calcagno
María
M
Gonzalez
Claudio
C
Jadzinsky
Mauricio
M
D001794:Blood Pressure; D015992:Body Mass Index; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000473:pathology* / Q000503:physiopathology; D015150:Echocardiography, Doppler; D005260:Female; D006325:Heart Atria / Q000033:anatomy & histology*; D006352:Heart Ventricles / Q000033:anatomy & histology; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D015999:Multivariate Analysis; D009765:Obesity / Q000473:pathology* / Q000503:physiopathology; D011384:Proinsulin / Q000097:blood; D011627:Puberty / Q000502:physiology; D012044:Regression Analysis
D011384:Proinsulin