BACKGROUND: According to US-EPA report, the use of pyrethrins and pyrethroids has increased during the past decade, and their area of use included not only in agricultural settings, but in commerce, and individual household. It is known that urinary 3-PBA, major metabolite of pyrethroid, have some associations with health effect in nervous and endocrine system, however, there’s no known evidence that urinary 3-PBA have associations with obesity. METHOD: We used data of 3671 participants aged above 19 from the Korean National Environmental Health Survey in 2009–2011. In our analysis, multivariate piece-wise regression and logistic regression analysis were used to investigate the association between urinary 3-PBA (3-Phenoxybenzoic Acid) and BMI. RESULT: Log-transformed level of urinary 3-PBA had significantly positive association with BMI at the low-level range of exposure (p < 0.0001), and opposite associations were observed at the high level exposure (p = 0.04) after adjusting covariates. In piece-wise regression analysis, the flexion point that changes direction of the associations was at around 4 ug/g creatinine of urinary 3-PBA. As quintiles based on concentration of urinary 3-PBA increased to Q4, the ORs for prevalence of overweight (BMI ≥ 23 kg/m2) were increased, and the OR of Q5 was lower than that of Q4 (OR = 1.810 for Q4; OR = 1.483 for Q5). In the analysis using obesity (BMI ≥ 25 kg/m2) as outcome variable, significant associations were observed between obesity and quintiles of 3-PBA, however, there were no differences between the OR of Q5 and that of Q4 (OR = 1.659 for Q4; OR = 1.666 for Q5). CONCLUSION: Our analysis suggested that low-level of pyrethroid exposure has positive association with BMI, however, there is an inverse relationship above the urinary 3-PBA level at 4 ug/g creatinine. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40557-015-0079-7) contains supplementary material, which is available to authorized users.
Adult* ; Body Mass Index* ; Commerce ; Creatinine ; Endocrine System ; Environmental Health* ; Family Characteristics ; Humans ; Logistic Models ; Methods ; Multivariate Analysis ; Obesity ; Overweight ; Prevalence ; Pyrethrins

Gram-negative bacterial pathogens produce outer membrane vesicles (OMVs) and this secreted cargo plays a role in host-pathogen interactions. OMVs isolated from Burkholderia cepacia induce the cytotoxicity and pro-inflammatory responses both in vitro and in vivo, but OMV components associated with host pathology have not been characterized. This study analyzed the proteomes of OMVs produced by B. cepacia ATCC 25416 and investigated whether proteins in B. cepacia OMVs were responsible for host pathology in vitro. Proteomic analysis revealed that a total of 265 proteins were identified in B. cepacia OMVs. Of the 265 OMV proteins, 179 (67.5%), 32 (12.1%), 27 (10.2%), 17 (6.4%), and 10 (3.8%) were predicted to be located in the cytoplasm, inner membrane, periplasmic space, outer membrane, and extracellular compartment, respectively. Several putative virulence factors were also identified in B. cepacia OMVs. B. cepacia OMVs slightly induced the cytotoxicity in lung epithelial A549 cells, but there was no difference in cytotoxic activity between intact OMVs and proteinase K-treated OMVs. B. cepacia OMVs stimulated the expression of pro-inflammatory cytokine and chemokine genes in A549 cells, but the expression of these cytokine genes was significantly inhibited in A549 cells incubated with proteinase K-treated OMVs. In conclusion, our results suggest that proteins in B. cepaciaOMVs are directly responsible for pro-inflammatory responses in lung epithelial cells.