Prehypertension in outpatient obese children

The aim of the study was to analyze the prevalence of prehypertension (PH) in obese (OB) children and its relation with estimated glomerular filtration rate (eGFR) and left ventricular (LV) function.

The study included 447 OB and 131 normal-weight children. PH was defined according to the criteria proposed by the National High Blood Pressure Education Program Working Group on High Blood Pressure in Children and Adolescents. Insulin sensitivity was evaluated by HOMA(IR), and eGFR was calculated by Schwartz's formula. LV function was analyzed by echocardiography in 165 OB children.

PH was observed in 79 OB children (17.7%) and in 2 (1.5%) controls. Among OB children, those with PH had greater percentage of males (P < 0.05), higher level of body mass index (BMI) (P < 0.001), waist circumference (WC) (P < 0.005), and HOMA(IR) (P < 0.001), compared to PH- children. The two groups did not differ for eGFR and LV function. At logistic regression analysis, PH was independently associated with male gender (P < 0.025) and HOMA(IR) (P < 0.002). Gender analysis showed that boys with PH presented higher levels of BMI (P < 0.005), WC (P < 0.01), HOMA(IR) (P < 0.001), and triglycerides (P < 0.005) compared to PH- boys. Females with PH were older and in more advanced postpubertal stage, had higher BMI, WC (P < 0.05, for all), and HOMA(IR) (P < 0.025), compared to PH- girls.

In a population of outpatient OB children, the prevalence of PH was 17.7% and boys were more likely than girls to have PH. This condition is characterized by insulin resistance in both sexes but no impairment in glomerular and LV function.