Gender Differences in the Effect of Adiposity on Markers of Cardiovascular Risk in Prepubertal Children

Introduction: In recent 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 old children. 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, 24-hour ambulatory blood pressure, and pulse wave velocity. We classified obesity according to World Health Organization body mass index for age reference values. Results: When adjusting for age and height, non-highdensity lipoproteins 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 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-insulin resistance levels 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 = 0.003). Overweight girls had an increase of 0.25 m/s and obese girls an increase of 0.50 m/s in pulse wave velocity. No significant effect was found among boys (p = 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 pulse wave velocity was only associated with overweight and obesity in females.