Is fasting insulin associated with blood pressure in obese children?

Primary objective : We tested whether fasting insulin levels are associated with blood pressure in a large sample of obese children. Subjects and methods : Three hundred and rf ty obese children (F:M ratio = 1.03) of 10.1 +/- 2. 7 y of age (mean +/- SD) were consecutively enrolled at an Outpatient Paediatric Clinic. Obesity was diagnosed on the basis of a relative weight for age > 120% and hypertension on the basis of a systolic (SBP) or diastolic (DBP) blood pressure > 95th percentile for age after adjustment for height (Ht). Main outcome and results : Insulin was significantly higher in hypertensive. n = 202; 58%) than normotensive. n = 148; 42%) children (16 vs 14 mu U mL(1), geometric mean, p < 0.01, ANOVA) but the difference was not clinically relevant. Moreover, (log-transformed) insulin explained only 7 and 4% of SBP and DBP variance, respectively (p < 0.0001 for both) and this contribution disappeared after the confounding effects of age, weight or other anthropometric dimensions were taken into account (p = ns, ANCOVA). Conclusions: This study does not support the hypothesis of a clinically relevant association between fasting insulin and blood pressure in obese children.