P0204 - Diurnal blood pressure abnormalities and cardiovascular risk markers in obese pediatric patients

Background: Hypertension is a recognized concern in obese children and can include short-term and long-term consequences. Early life hypertension is linked to increased risks for other cardiovascular disease states during adulthood, with large social and medical costs. 24-hr ambulatory blood pressure monitoring (ABPM) has become one of the most important tools in diagnosing hypertension in children and circadian patterns of blood pressure may be important disease-risks predictors.
Design/

Methods: We conducted a retrospective chart review with patients aged 7-21 years who underwent 24-hr ABPM at Kentucky Children’s Hospital from August 2012-June 2017. Retrospective data collection was approved by the IRB at the University of Kentucky. Exclusion criteria included conditions that could affect blood pressure including chronic kidney disease, congenital heart disease, and thyroid disease. Subjects were categorized by BMI into normal (below 85th percentile), overweight (85 -95th percentile), stage I obesity (95-119th percentile), stage II obesity(120-139th) and stage III obesity (>140th). Non-dipping was defined as a nocturnal BP reduction of <10%. Cardiac ultrasound evaluations (when available), blood lipid panels, thyroid status, and metabolic status were compared among groups. All statistical analyses were performed with IBMSPSS Statistics version 23 and a p<0.05 was considered significant. Statistical tests included ANOVA, Chi-square, and Somer’s D test as appropriate.

Results: 263 patients were included in the analysis, of whom 70 were normal weight, 33 overweight, 55 stage I obesity, 53 stage II, and 52 stage III obesity. There was no significant difference between normal weight and obese groups for prevalence of hypertension but there was a greater prevalence of SBP non-dipping in obese patients with increasing BMI (p=0.008). Furthermore, non-dippers had a significantly elevated LVMI as well as abnormal lab values for uric acid, blood lipid panel, creatinine, and TSH. Of the subset of patients that received sleep studies the frequency of obstructive sleep apnea was 60%, with AHI index averaging 3.152 +/- 0.54 and only a minority (20%) were compliant with their CPAP protocol.

Conclusion(s): These findings demonstrate that obese children constitute a large proportion of hypertensive children and the etiology of hypertension may be unique relative to other forms of pediatric hypertension (i.e. renal disease). Abnormal diurnal BP patterns are common in severely obese hypertensive children and several other cardiovascular disease risks are prevalent in this population. Further studies utilizing the ABPM measures on risks stratification in this very high-risk population are clearly warranted.