Gender differences in the effect of adiposity on markers of cardiovascular risk in prepubertal children [Diferenças entre géneros no efeito da adiposidade nos marcadores de risco cardiovascular em crianças pré-púberes]

INTRODUCTION: In the last years, evidence has started to emerge on the presence of cardiometabolic differences between genders before puberty. This study aims to evaluate if the association between obesity and markers of cardiovascular risk is different between genders in 8 to 9-year-olds. METHODS: Cross sectional study of 315 children (167 boys) aged 8-9 years old, followed in the birth cohort Generation XXI (Portugal). Measures included anthropometrics, insulin resistance levels (HOMA-IR), 24-hour ambulatory blood pressure and pulse wave velocity (PWV) were measured. We classified obesity according to WHO body mass index(BMI)-for-age reference values. RESULTS: When adjusting for age and height, non-HDL cholesterol was higher among overweight and obese girls (16.22 and 19.75 mg/dL, respectively) and there was no effect among boys, although the interaction term with gender was not significant. The level of triglycerides was higher among the obese in both genders. Obese and overweight girls and obese boys showed increased log-HOMA-IR compared to their normal weight counterparts (0.09 increase for overweight girls, 0.29 for obese girls and 0.12 for obese boys) and gender had a significant interaction in this effect (p for interaction=0.003). Overweight girls had an increase of 0.25 m/s in PWV and obese girls an increase of 0.50 m/s. No effect was found among boys (p for interaction=0.031). DISCUSSION: Gender plays a significant role in the effect of adiposity on insulin resistance and pulse wave velocity. A stronger association between obesity and insulin resistance was observed in girls and PWV was only associated with overweight-obesity in females.This project was supported by FEDER funds from Programa Operacional Factores de Competitividade – COMPETE (FCOMP-01-0124-FEDER-028751) and by national funds from the Portuguese Foundation for Science and Technology, Lisbon, Portugal (PTDC/DTP-PIC/0239/2012). Liane Correia-Costa was supported by the Portuguese Foundation for Science and Technology (grant SFRH/SINTD/95898/2013)