Relationships between Dioxin/Polychlorinayted Biphenyls and Placental n-3 and n-6 Polyunsaturated Fatty acid Status – A Cross-sectional study on Pregnant Women from Central Taiwan.

Autor: Pei-Yi Sun, 孫珮儀
Rok vydání: 2009
Druh dokumentu: 學位論文 ; thesis
Popis: 97
N-6 and n-3 polyunsaturated fatty acids (PUFA), especially DHA (docosahexaenoic acid, C22:6 n-3) and ARA (arachidonic acid, C20:4 n-6) are important in perinatal development. Because of the similar chemical properties and origins of food sources, it is possible that critical delivery of these n-6 and n-3 LCPUFA to the fetus may also serve to increase the fetal exposures to lipophilic organo-chlorines. This study was aimed to examine relationships between placental n-3 and n-6 PUFA and placental PCDD/Fs and PCBs toxic equivalent (TEQ) levels in 34 pregnant women from central Taiwan. Linear and positive associations were observed between monounsaturates (C16:1 n-7, C18:1 n-9, C20:1 n-9) and low, mid and high TEQ levels of PCDFs (p trend < 0.05). On the other hand, trends of decreases in n-6 PUFA including C20:3 n-6 (p trend=0.011), C20:4 n-6 (p trend=0.020), C22:4 n-6 (p trend=0.036) and C22:5 n-6 (p trend=0.003) were observed as PCDF increased from low to high TEQ levels. Similarly, trends of decreases in these n-6 PUFA were also found against increased PCDDs levels; however, only C20:3 n-6 (p trend=0.054) and C22:5 n-6 (p trend=0.067) were correlated and C20:4 n-6 were marginally correlated with PCDDs levels. For n-3 PUFA, only DHA was significantly decreased as PCDFs levels increased (p trend=0.025). Linear and positive associations were observed between monounsaturates (C16:1 n-7, C18:1 n-9) and low, mid and high TEQ levels of total PCBs (p trend < 0.05). Trends of increases in PUFA including C18:2 n-6 (p trend=0.035), C18:3 n-3 (p trend=0.020) were observed as dioxin-like PCBs increased from low to high TEQ levels. After adjusting for potential confounders (age, education, income, BMI) only PCDFs was marginally and negatively correlated with placental DHA (beta=-0.403, p=0.196) and total dioxin (PCDD/Fs and dioxin-like PCBs) was marginally and negatively correlated with placental ARA (beta=-2.114, p=0.057). Increases in dioxin exposures appeared to correlate with trends of decreases in some n-3 and n-6 PUFA including DHA and ARA. Mechanisms regarding placental DHA and ARA transfer which may be interfered by dioxin exposure warrant further investigations.
Databáze: Networked Digital Library of Theses & Dissertations
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