Ambulatory blood pressure parameters in office normotensive obese and non-obese children: relationship with insulin resistance and atherosclerotic markers.

OBJECTIVES: To determine differences in ambulatory blood pressure (ABP) parameters between office normotensive obese and non-obese children and to evaluate correlations of ABP parameters with insulin resistance and the lipid profile. SUBJECTS AND METHODS: Thirty-eight obese [body mass index (BMI) above the 95th percentile] and 38 non-obese children aged 9-17 years were recruited. All subjects who were normotensive during office visits and who underwent 24-hour ABP monitoring were evaluated. Insulin resistance and the lipid profile were also evaluated. RESULTS: The mean daytime, night-time and 24-hour systolic blood pressure (SBP) and the daytime and 24-hour diastolic blood pressure (DBP) in normotensive obese children were significantly higher compared to the values in non-obese children (p < 0.05). There was no difference in the frequency of nocturnal non-dippers and nocturnal hypertension (night-time SBP at or above the 95th percentile) between the two groups (p > 0.05). Children with night-time SBP at or above the 95th percentile and non-dippers had higher atherosclerotic markers than children with night-time SBP below the 95th percentile and dippers (p < 0.05). In logistic regression analysis, the low-density lipoprotein cholesterol (LDL-C):high-density lipoprotein cholesterol (HDL-C) ratio and night-time SBP had significantly positive associations with being obese in adolescents (OR 6.54, 95% CI 1.15-37.07, p = 0.03, and OR 1.1, 95% CI 1.01-1.19, p = 0.02, respectively). CONCLUSION: Normotensive obese children had higher ABP parameters. A high LDL-C:HDL-C ratio and night-time SBP were associated with an increased risk of being obese. High LDL-C:HDL-C ratios and total cholesterol:HDL-C levels in children and adolescents may be risk factors for night-time hypertension.