Yingyan Gong

Visual dysfunction in workers exposed to a mixture of organic solvents.

The aim of this study was to investigate the relationship between the workers occupationally exposed to a mixture of organic solvents and their visual functions. Here the visual functions included color vision (CV), visual contrast sensitivity (CS) and visual evoked potentials (VEP). Test subjects were 182 workers at 53 furniture factories in the same industrial area of Japan. As control, a group consisted of 96 workers without exposure to any organic solvent was also tested. Exposure assessments were made both by the environmental concentration and biological monitoring. CV and CS tests were carried out for all the subjects. VEP was measured for 21 exposed subjects who were considered to have impaired CV and CS. In the results, the color confusion index (CCI) values of the exposed subjects were significantly higher than that of the age-matched controls (P<0.01). Their CS values were significantly lower than those in the controls at spatial frequencies of 6 and 12 cycles per degree (cpd) (P<0.01 and <0.05, respectively). A significant correlation between the concentration of urinary methylhippuric acid and contrast sensitivity was found by a multiple regression analysis (P<0.05). CCI showed a negative correlation at all spatial frequencies of CS in a simple regression analysis, no abnormal data were found by the VEP test in the exposed subjects who were found to have impaired CV and CS. The results suppose that a low concentration of the mixed organic solvents might affect the retina and optic nerve. However, it needs to be further researched if such an impact affects the Brodmanns areas of visual cortex in the brain.

Relationship of beta2-microglobulin to arterial stiffness in Japanese subjects.

β2-Microglobulin (β2m) is related to inflammatory diseases, but there have been few reports of a relationship between β2m and atherosclerosis. We have examined the influence of β2m on brachial-ankle pulse wave velocity (baPWV) to clarify whether it is related to arterial stiffness. baPWV, β2m, C-reactive protein (CRP), and conventional risk factors were measured in 614 males and 158 females. The adjusted means of baPWV were compared with the quartiles of β2m, and significant differences in baPWV were observed across the quartiles of β2m (p=0.037). After being adjusted for potential confounders, quartile 4 of β2m, quartile 4 of CRP, and the combination of high β2m plus high CRP were significantly associated with a high value of PWV (quartile 4 of β2m: odds ratio [OR] 2.53, 95% confidence interval [CI], 1.31–4.89; quartile 4 of CRP: OR 2.27, 95% CI, 1.18–4.34; high β2m plus high CRP: OR 5.60, 95% CI, 2.38–13.2). These results suggest that β2m is associated with an increase of arterial stiffness. Further studies are needed to clarify whether β2m is related to atherosclerotic diseases, and whether the combination of β2m and CRP measurement is a useful predictor for the development of atherosclerosis.

Relationships of C-reactive protein, uric acid, and glomerular filtration rate to arterial stiffness in Japanese subjects

The relationships between C-reactive protein (CRP), uric acid (UA), glomerular filtration rate (GFR), and arterial stiffness have not been fully investigated. The aim of this study was to clarify whether CRP, UA, and estimated GFR are related to arterial stiffness estimated using brachial-ankle pulse wave velocity (baPWV). The subjects were local government employees (3412 men and 854 women). baPWV, CRP, UA, GFR, and conventional risk factors were evaluated. Multiple linear regression analyses revealed that CRP and UA were significantly related to an elevation of PWV in male and female subjects, and that the estimated GFR was significantly related to an elevation of PWV in male subjects. Significant progressive increases in baPWV were observed across the quartiles of CRP in male subjects and for UA in male and female subjects. In female subjects, the relationship of quartile CRP to baPWV had marginal significance (P=0.055). But, in male and female subjects, quartile of estimated GFR had no significant association with PWV. These results suggest that CRP and UA are associated with an increase of arterial stiffness in male and female subjects, and that estimated GFR is possibly related to arterial stiffness in male subjects.

Relationship of Helicobacter pylori Infection to Arterial Stiffness in Japanese Subjects

The role of Helicobacter pylori in the pathogenesis of atherosclerosis remains controversial, and the relationship between H. pylori and the early stage of atherosclerosis has not been fully investigated. We investigated the influence of H. pylori infection on arterial stiffness to clarify whether H. pylori infection is related to early-stage atherosclerosis. The subjects were 3,412 males and 854 females. Anti-H. pylori antibody and C-reactive protein (CRP) level were measured. Arterial stiffness was evaluated using the brachial-ankle pulse wave velocity (PWV). In multivariate logistic repression analyses of male subjects, H. pylori seropositivity (odds ratio [OR] 1.27 [95% confidence interval, 1.05–1.52]) and H. pylori seropositivity with a high CRP value (>0.045 mg/dl) (OR 1.50 [1.14–1.98]) were significantly related to a high value of PWV. In the analyses of male subjects aged ≤49 years, H. pylori seropositivity (OR 1.40 [1.04–1.88]) and H. pylori seropositivity with a high CRP value (OR 1.81 [1.16–2.80]) were also significantly related to a high value of PWV. However, in male subjects aged ≥50 years and female subjects, no associations were found. These results suggest that inflammation following H. pylori infection contributes to the early stage of atherosclerosis in younger males.

Effects of styrene exposure on vibration perception threshold.

OBJECTIVES We aimed to investigate whether styrene can affect the vibration perception threshold (VPT) and to examine the dose-effect relationship at current and past styrene exposure levels. METHODS VPT was examined using a Vibrometer (TM-31A) for 67 subjects exposed to styrene in a fiberglass reinforced plastic boat plant and 151 non-exposed subjects. We selected 67 age-matched controls out of the non-exposed subjects for the analyses. End shift urinary metabolites of styrene were measured for evaluation of the dose-effect relationship for the past eight years and at the time of VPT measurement. The current exposure level was expressed by the end shift urinary mandelic acid (MA) and phenylglyoxylic acid (PGA) levels. Cumulative exposure index (CEI) were calculated based on the exposure frequency and urinary MA concentrations measured for the past eight years. RESULTS The VPT of the exposed group was higher than that of non-exposed group. Multiple regression analysis revealed that past maximum exposure level and age were significant factors explaining the variation of VPT. Dose-effect relationship was recognized in upper limbs but not in lower limbs among exposure groups. When the exposed group was divided into high- and low-level groups for the past maximum exposure level by the cutoff point of MA 0.83 g/g cr (equivalent to 50 ppm in air) and compared to the control group, we found significant differences in the VPT in upper limbs, between the high-level exposed group and control group, and in lower limbs, between both of the high- and low-level exposed groups and the control group. CONCLUSION If the maximum concentration of styrene exposure exceeded 50ppm in the past, effects of exposure to styrene on the VPT are likely to persist.