Abstracts: ISEE 21st Annual Conference, Dublin, Ireland, August 25-29, 2009: Oral Presentations
*Department of Environmental and Occupational Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan; †Department of Internal Medicine, Division of Endocrinology and Metabolism, National Cheng Kung University, Tainan, Taiwan; ‡Research Center of Environmental Trace Toxic Substance, National Cheng Kung University, Tainan, Taiwan; and §Department of Industrial Safety and Health, Hung Kuang University, Taichung, Taiwan.
Abstracts published in Epidemiology have been reviewed by the organizations of Epidemiology. Affliate Societies at whose meetings the abstracts have been accepted for presentation. These abstracts have not undergone review by the Editorial Board of Epidemiology.
Background and Objective:
Metabolic syndrome (MetS) is a cluster of metabolic risk factors and a reliable predictor of diabetes and cardiovascular disease. However, little is known on the impact of dioxins on insulin resistance and components of MetS and their interrelationship. The aims of this study were to study the impact of PCDD/Fs on MetS and some of its components (blood pressure and insulin resistance) and examine the associations between the prevalence of MetS, homoeostasis-model-assessment insulin resistance (HOMA-IR), and serum PCDD/F concentrations, and their potential interaction.
We investigated MetS-related factors and serum dioxin levels in 1423 non-diabetic persons near a deserted pentachlorophenol factory. We also used factor analysis with a set of core variables considered central features of MetS and dioxins to group similar risk factors. Finally, we investigated associations between the risk of insulin resistance (HOMA-IR>75th percentile), MetS, and serum dioxin levels and their potential interaction.
Serum dioxins were significantly increased with the number of MetS components (Ptrend < 0.05). In factor analysis, four risk factors: lipidemia, blood pressure, body size, and glycemia, accounted for 73.1% of the variance in the 10 core factors in participants and revealed that dioxins were linked to MetS through shared correlations with high blood pressure. After adjusting for confounding factors, participants with higher serum dioxin levels or insulin resistance were at significant risk for having MetS (adjusted odds ratio [AOR] 1.40 [95% CI 1.03-1.90] for dioxins; AOR 6.69 [95% CI 5.03-8.99] for insulin resistance). Participants exposed to higher levels of dioxins and possessed insulin resistance had a much greater risk (AOR 20.1 [95% CI 10.0-43.6]) of having MetS.
High-dose exposure to dioxins is suggested to be a blood pressure-related factor which raised MetS risk by modifying the effect of insulin resistance on MetS.