ABSTRACT
Background As a group of environmental pollutants, polycyclic aromatic hydrocarbons (PAHs) are neurotoxic and may cause mild cognitive impairment (MCI) by inducing inflammation. Whether neutrophil-lymphocyte ratio (NLR), an inflammatory indicator, plays a mediating role in the relationship between PAHs exposure and MCI is unclear yet. Objective To investigate a potential mediating role of NLR in the association between exposure to PAHs and MCI in coke oven plant workers. Methods Eleven urine hydroxylated PAHs (OH-PAHs) of 530 coke oven plant workers were determined by high performance liquid chromatography tandem mass spectrometry. NLR was derived from participants' routine blood examination results using a fully automated haematology analyser. The associations between urinary OH-PAHs and MCI were analyzed by binary logistic regression, the associations between urinary OH-PAHs and NLR were analyzed by multiple linear regression, and the role of NLR in the relationship between urinary OH-PAHs and MCI was evaluated by mediating effect analysis. Results After controlling for confounding factors and other OH-PAHs, the results of binary logistic regression showed that for every e-fold (e is the base of the natural logarithm) increase in the concentration of 2-hydroxynaphthalene (2-OHNap) and 1-hydroxyphenanthrene (1-OHPhe), the OR (95%CI) values of reporting MCI positive were 1.21 (1.02, 1.43) and 1.25 (1.04, 1.51) respectively. For each unit increase of NLR, the OR (95%CI) of reporting MCI positive was 1.56 (1.12, 2.18). The results of multiple linear regression showed that each unit increase in natural log-transformed levels of 1-OHPhe was associated with 0.05 (95%CI: 0.01, 0.10) increase of NLR. The results of mediating effect analysis showed that the association between urinary 1-OHPhe and MCI was partially mediated by peripheral blood NLR, with a mediation ratio of 9.8%. Conclusion Exposure to PAHs in coke oven plant workers may increase the risk of reporting MCI positive partially through increased NLR in peripheral blood.
ABSTRACT
Background As a complex organic pollutant, polycyclic aromatic hydrocarbons (PAHs) exposure shares the common exposure characteristics of multiple hydroxyl metabolites. Most studies have analyzed independent effect of each PAHs metabolite and have adjusted for the potential confounding effects induced by other metabolites concomitantly, without considering possible interactions among them. Proper statistical methods are needed to study their toxic effects. Objective To explore the applicability of logistic regression, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) in evaluating the correlation between mixed exposures to exogenous chemicals and health outcomes, compare the advantages and limitations of the three models, and propose analytical strategies for evaluating the health effects of mixed chemical exposure for application in the analysis of the association between PAHs exposure and cognition. Methods Urine samples were collected of workers from a coke oven plant and a water treatment plant in Shanxi Province, who participated in their routine employee healthexamination. Mono-hydroxylated PAHs were detected by high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS), cognitive function was assessed using the Montreal Cognitive Assessment (MoCA). A cut-off value of MoCA less than 26 was considered mild cognitive impairment (MCI). According to a predetermined inclusion and exclusion criteria, 1 051 cases were included in the final data analysis. Logistic regression, WQS regression, and BKMR were used to analyze the relationship between PAHs metabolites and MCI. Results The prevalence rate of reporting MCI among the 1 051 workers was 21.7% (228/1 051). The concentration of 2-hydroxynathalene (2-OHNAP) was the highest among the 11 PAHs metabolites with a median concentration of 0.30 μg·L−1, followed by 9-hydroxyphenanthrene (9-OHPHE) (0.26 μg·L−1). There were significant differences between the two groups in 2-OHNAP, 1-hydroxynaphthalene (1-OHNAP), 2-hydroxyfluorene (2-OHFLU), 9-OHPHE, 1-hydroxyphenanthrene (1-OHPHE), and 1-hydroxypyrene (1-OHPYR) (all Ps<0.05). In the logistic regression, 2-OHNAP and 2-OHPHE were associated with MCI, and the OR (95%CI) for reporting MCI was 1.28 (1.01-1.67) and 1.27 (1.00-1.72) for each 10-fold increase in 2-OHNAP and 2-OHPHE concentrations, respectively. In the WQS regression analysis, the WQS index was positively correlated with the prevalence rate of reporting MCI (OR=1.37, 95%CI: 1.10-1.72). In the BKMR analysis, compared with the median exposure levels of all chemicals, the overall effect was statistically significant when all PAHs metabolites concentrations were at or above their 30th percentile; when all exposures were at the 75th percentile, the risk of reporting MCI increased by 6%. Conclusion Based on the results of these three models, 2-OHNAP and 2-OHPHE are the most important factors related to cognitive. It is recommended to use a combination of traditional logistic regression and either WQS or BKMR to study the association between PAHs and MCI.
ABSTRACT
Objective To investigate the correlation between the location of ruptured intracranial vertebral artery dissecting aneurysm (VADA)and the outcome after endovascular treatment. Methods Thirty-six patients with ruptured intracranial VADA undergoing endovascular treatment were enrolled retrospectively. According to the relationship between VADA and the location of the opening of posterior inferior cerebellar artery(PICA),they were divided into 3 groups:proximal to PICA group (n=13), distal to PICA group (n=13),and PICA involvement group (n=10). The demographic data, vascular risk factors, clinical features, imaging features, endovascular treatment mode, postoperative complications, and differece of the good outcome rate(defined as the modified Rankin scale 0-2)after 6 months of treatment were compared.Results Seven patients in the proximal to PICA group received reconstructive endovascular treatment (RET), and 6 received endovascular internal trapping(EIT);the good outcome rate was 100%(13/13).Seven patients in the distal to PICA group received RET,6 were treated with EIT;the good outcome rate was 84.6%(11/13).Four patients in the PICA involvement group received RET,and 6 received EIT,and 2 of them received contralateral vertebral artery retrograde PICA stenting combined with VADA segment and proximal vertebral artery coil embolization;the good outcome rate was 60.0%(6/10). There were significant differences in the overall outcome good rate among the 3 groups (P<0.05). The good outcome rate in the PICA involvement group was significant lower than that in the proximal to PICA group,and significantly lower than that in the proximal to PICA combined with distal to PICA group(P<0.05).Multivariate logistic regression analysis showed that only Fisher grade 3-4 was the independent risk factor for poor outcome (odds ratio 28.0, 95% confidence interval 1.71-458.82; P=0.020). Conclusions The surgical options of endovascular treatment for ruptured intracranial VADA needs to evaluate the relationship between the location of dissecting aneurysms and the PICA origin. The risk of endovascular treatment in patients with intracranial VADA involving the origin of PICA is higher and it may affect the outcome.