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 5-16y 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 (r² = 0.23; P <0.01), IR_HOMA (r² = 0.17; P <0.02), systolic and diastolic blood pressure (r²=0.20; P=0.006 and r² = 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 ≥ 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.