Obesity in Spanish schoolchildren: relationship with lipid profile and insulin resistance

This article reports cross-sectional data from a total of 1048 children, 6 to 8 years of age, categorized by presence or absence of obesity, who participated in a voluntary survey of cardiovascular risk factors in Spain over the period of 1998 to 2000, to establish the relationship between obesity and its metabolic consequences at this age. The prevalence of obesity and overweight were 9.4% and 15.7%, respectively, in boys and 10.5% and 18.0%, respectively, in girls. We observed that, in both sexes, obese children had higher triglycerides and lower high-density lipoprotein-cholesterol levels than non-obese children. No differences were found in plasma glucose or low-density lipoprotein-cholesterol levels between normal and obese children. However, we observed that insulin levels and the homeostasis model assessment for insulin resistance were significantly (p<0.001) higher in obese children of both sexes but that free fatty acid levels were lower in obese children than in nonobese children, with a statistical significance in girls (0.72+/-0.30 vs. 0.61+/-0.16 mEq/liter). In summary, our survey found some metabolic consequences of obesity similar to those found in adults (elevated triglycerides, insulin, and the homeostasis model assessment for insulin resistance, and lower high-density lipoprotein-cholesterol). However, other features (glucose, total cholesterol, low-density lipoprotein-cholesterol, and free fatty acid levels) were found to behave differently, indicating that the association of obesity with risk factors seems to change as the children age and may depend on the chronology of sexual maturation.