Background

Children with obesity(CWO) are at increased risk for hypertension (HTN).If blood pressure (BP) is elevated, AAP guidelines recommend lifestyle intervention(LI) (healthy diet, sleep and physical activity) for 6-12 months. If BP is Stage I, LI is 3 months, if Stage II then after evaluation the child is treated with medication. Due to recent changes in guidelines, more CWO are meeting criteria for all stages. The primary purpose of this study is to see if change in systolic BP(SBP) over time depends on the baseline BMI percentile (%BMIp95) in CWO with elevated SBP receiving intensive LI.

Methods

Data from subjects in a pediatric weight management program was retroactively reviewed. Inclusion criteria: baseline SBP >120 mm Hg, age 6-18, 2 or more visits, and baseline HbA1c < 6.5%. Baseline %BMIp95 was categorized as: Overweight(OW)85-94%, Grade 1:95-119%, Grade 2: 120-139%, Grade 3: 140-159%, Grade 4:>159%. Subject characteristics were summarized using median with minimum and maximum, or frequency with percentage. A linear growth model with unstructured covariance was used to model SBP over time.

Results

238 subjects met inclusion criteria. Visits within 12 months of baseline were assessed. Change in SBP over time did not significantly depend on BMI group(P=0.374). On average, SBP declined over time for all BMI categories. Average SBP decreased by 0.96 (p=0.28), 0.42 (p=0.07), 0.83 (p<0.001), 0.30 (p=0.2) and 0.77 (p<0.001) mm Hg per month for subjects who were OW,followed by grades 1 to 4 respectively. SBP was significantly higher at baseline for Grade 4 compared to OW subjects.(mean 130.7 vs 120 mmHg;P=0.04).

Conclusions

Current recommendations are for LI up to 12 months in CWO with elevated BP. We observed decreases in mean SBP over time (12 months) in subjects in all BMI groups. However despite intensive LI Groups 3 and 4 did not achieve SBP <120 mm Hg, suggesting that severely obese CWO are at higher risk for sustained elevated SBP than those with %BMIp95 <140 and not as responsive to LI.