Adjusting Adiposity and Body Weight Measurements for Height Alters the Relationship With Blood Pressure in Children

Abstract

Adiposity measures are associated with increased pediatric blood pressure (BP). However, this correlation can be confounded by the relationship of both variables to height. We evaluated whether adiposity and anthropometric measures were associated with pediatric BP before and after adjusting each value for height. Participants included 281 African-American (AA), European-American (EA), and Hispanic-American (HA) children aged 7-12 years. BP percentiles were calculated according to pediatric guidelines using the average of four measurements. Total fat mass was determined using dual-energy X-ray absorptiometry. Socioeconomic status (SES) was calculated with the Hollingshead index. Adiposity measures were indexed for height using log-log regression analysis. Partial correlations identified measures associated with BP. Linear regression was used to test the association of those measures with absolute BP, whereas logistic regression was used to evaluate the odds for hypertension. More AAs (16.3%) presented with potential hypertension than EA (5.1%) or HA (2.7%) children. After adjusting for covariates, fat mass, body mass index, and waist circumference were positively significantly associated with absolute BP and hypertension in AA and EA children (P < 0.05). When these measures were height-indexed, only waist remained significantly positively associated with hypertension risk in these two groups. No measures were significantly associated with BP among HA children. In this multiethnic pediatric population, waist circumference was the strongest significant adiposity predictor of hypertension risk among AA and EA children. Additional research is needed to determine which environmental and genetic factors contribute to pediatric hypertension, particularly among HA groups.