Prevalence and risk factors for pre-hypertension among adolescents exposed to volcanic air pollution on Hawaiʻi Island

Abstract

We tested the hypothesis that exposure to volcanic air pollution (vog) is associated with elevated blood pressure (BP) in a cohort of Hawaii Island school children. Between September, 2009 and May, 2010, we measured BP in 807 participants enrolled in the Hawaii Island Children's Lung Assessment Scientific Study (HICLASS). The initial cohort of 1,986 children had been recruited in 2002-2003 from 29 Hawaii Island schools in areas with different vog exposure. Data were analyzed by uni-and multivariate logistic regression models. The mean age was 17; 51% were boys; 62% were of more than 1 race; mean BMI was 24.3 (125 had BMI>30); 32% reported asthma; 56% reported exposure to environmental tobacco smoke (ETS). Vog exposure (n) was categorized as low (168), intermittent (263), SO2 (48), or acid (328). The mean BP was 119/70 and the prevalence of BP>120/80 was 8.9%. Univariate analysis showed an association with male gender (OR 3.5, p<0.005) and obesity (OR 4.7, p<0.05), but not with vog or ETS. Multivariate analyses run separately for boys and girls (adjusting for race, BMI, asthma, tobacco smoke exposure) showed no association between BP>120/80 and vog exposure, but a strong association with obesity in both boys and girls. This study was limited by a single measurement of BP in a cross-sectional design. Longitudinal follow up, addressing obesity and other risk factors will be important to understand the relative contribution of vog and other factors in developing hypertension.