Abstracts: ISEE 22nd Annual Conference, Seoul, Korea, 28 August–1 September 2010: Climate Change and Environmental Health
To quantify the association between health indices; systolic blood pressure (SBP, mm Hg), diastolic blood pressure (DBP, mm Hg), brachial artery diameter (cm), internal carotid artery diameter (cm) and weather variables; discomfort index (DI), apparent temperature (AT), heat index (HI), and ultra violet index (UVI) with categorization using different cutoff point for the short term exposure.
A total of 103 participants were involved in this panel study and the biological variables were collected once every month with meteorological information such as DI, AT, HI, and UVI. Mixed effects model analysis was used to quantify the associations between health outcomes and the meteorological variables after adjusting for school, sex, current smoking status, and body mass index (BMI).
The biological outcomes of the panel showed significant changes by both DI and AT while less changes by HI and UVI. Through current DI and AT categorization set by Korea Meteorology Administration, SBP declined by 2.65 (95% CI: −3.72, −1.58) and 1.4 (95% CI: −2.41, −0.434) and DBP declined by 1.66 (95% CI: −2.51, −0.805) and 0.903 (95% CI: −1.69, −0.121), respectively. On the other hand, when the newly categorized cutoff point out of mixed effect model is applied to DI and AT, SBP declined by 5.23 (95% CI: −7.06, −3.40) and 2.86 (95% CI: −3.96, −1.75), and DBP by 4.18 (95% CI: −5.57, −2.79) and 1.33 (95% CI: −2.21, −0.448). Declines of SBP and DBP can explain increase of brachial artery diameter and internal carotid artery diameter.
We found that change of weather affects human health outcomes including blood pressure and the effect size is bigger when the higher level of cutoff point is applied than the current standard. This suggests the possibility of recategorizing current cutoff values upward to the higher level to reflect Koreans' biological response.