The utility of ambulatory blood pressure monitoring in obese children

Relationship of ambulatory blood pressure and body mass index to left ventricular mass index in pediatric patients with casual hypertension

Both obesity and hypertension are associated with left ventricular hypertrophy (LVH) in children. Our objective was to compare the prevalence of LVH in obese and nonobese subjects with casual hypertension who underwent ambulatory blood pressure monitoring (ABPM). Untreated children (aged 6-20 years) underwent 24-hour ABPM, and left ventricular mass index (LVMI) was measured. Subjects were classified into three groups: white coat hypertension (WCH), prehypertension (pre-HT), and hypertension (HT). The prevalence of LVH was compared between obese and nonobese subjects among the groups. Of 69 children who underwent ABPM, thirty-two patients (46%) had WCH, 13 (19%) had pre-HT, and 24 (35%) had HT. Mean age, BMI, and LVMI were similar in the groups (P = not significant [NS]). In all, 22 patients (32%) had LVH, with no difference among WCH versus pre-HT versus HT (37.5% vs. 46% vs. 16.7%, P = NS). Twenty-seven subjects (39%) were obese. The ratio of LVH in obese to nonobese was 55.5% to 16.6% (P = .001). In both pre-HT and WCH, patients with LVH had a significantly higher BMI z score (P = .02 and P = .01, respectively). LVMI correlated strongly with BMI z score (P = .0001) but not with any blood pressure parameter. Almost half of children with casual HT have WCH. LVH is prevalent in a third of children with HT, pre-HT, and WCH. In both pre-HT and WCH, patients with LVH were more likely to be obese. More than half of all the obese subjects had LVH. Obese children in all three groups may be at a greater risk for end organ damage.

Ambulatory blood pressure monitoring and blood pressure load in obese children

BACKGROUND AND OBJECTIVES

This study was aimed at evaluating the significance of blood pressure (BP) load in ambulatory blood pressure monitoring (ABPM) in obese children and adolescents.

SUBJECTS AND METHODS

ABPM was conducted for 60 selected patients who had visited Sunlin Hospital between January 2008 and August 2008. Patients were classified into 3 groups; an obese group whose body mass index (BMI) was > the 95th percentile, an overweight group whose BMI was > the 85th percentile but less than the 95th percentile, and a normal group whose BMI was below the 85th percentile. Overall mean BP, day and night BP and BP load were measured by ABPM.

RESULTS

Of the 60 patients, twenty-seven children belonged to the obese group, 9 and 24 to the overweight and the normal group, respectively. Among the three groups, the overall average systolic and diastolic BP, daytime diastolic BP, and systolic BP loads in daytime and nighttime were statistically different. Comparing the obese group with the normal group, systolic BP loads in daytime and nighttime in the obese group were significantly higher than those in the normal group. Also, the obese group had more patients whose BP loads were over 25% greater than the normal group while the difference in the number of patients with overall hypertension was not significantly different.

CONCLUSION

Assessment of children's BP through assessment of BP load is a more detailed and precise tool than assessment through mean BP using ABPM and BP can be better controlled using measurement of BP load.