Waist circumference as a predictor of cardiovascular and metabolic risk factors in obese girls.

OBJECTIVES: (a). to explore the relationship between waist circumference and certain cardiovascular risk factors in a group of girls; and (b). to assess the clinical relevance of waist circumference in identifying girls with higher cardiovascular risk across puberty.

SUBJECTS AND METHODS: One-hundred and fifty-five overweight or obese girls aged 5-16 y were recruited. Overweight and obesity were defined on the basis of BMI, according to Cole.

RESULTS: : Waist circumference was significantly correlated with plasma insulin (r=0.43; P<0.001), systolic blood pressure (r=0.22; P=0.007) and IR(HOMA) (r=0.40; P<0.001). A multivariate linear correlation analysis showed that, when adjusted for age and Tanner stage, waist circumference was significantly associated with plasma insulin (r(2)=0.23; P<0.01), IR(HOMA) (r(2)=0.17; P<0.02), systolic and diastolic blood pressure (r(2)=0.20; P=0.006 and r(2)=0.32; P<0.001, respectively). A logistic regression analysis, using IR(HOMA) as the dependent variable, showed that waist circumference was a significant independent risk factor of insulin resistance (IR(HOMA)>or=2.6) in this group of girls (OR 1.10; 95% CI 1.03-1.18; P=0.003), independently of their age and Tanner stage.

CONCLUSIONS: Waist circumference of these girls was independently associated with certain cardiovascular risk factors, in particular insulin resistance and diastolic blood pressure, independently of age and Tanner stage. Thus suggesting that waist circumference may be reasonably included in clinical practice as a simple tool that may help to identify sub-groups of obese girls at higher metabolic risk across puberty.