Not only baseline but cumulative exposure of remnant cholesterol predicts the development of nonalcoholic fatty liver disease: a cohort study

BACKGROUND AND AIM@#Remnant cholesterol (remnant-C) mediates the progression of major adverse cardiovascular events. It is unclear whether remnant-C, and particularly cumulative exposure to remnant-C, is associated with nonalcoholic fatty liver disease (NAFLD). This study aimed to explore whether remnant-C, not only baseline but cumulative exposure, can be used to independently evaluate the risk of NAFLD.@*METHODS@#This study included 1 cohort totaling 21,958 subjects without NAFLD at baseline who underwent at least 2 repeated health checkups and 1 sub-cohort totaling 2,649 subjects restricted to those individuals with at least 4 examinations and no history of NAFLD until Exam 3. Cumulative remnant-C was calculated as a timeweighted model for each examination multiplied by the time between the 2 examinations divided the whole duration. Cox regression models were performed to estimate the association between baseline and cumulative exposure to remnant-C and incident NAFLD.@*RESULTS@#After multivariable adjustment, compared with the quintile 1 of baseline remnant-C, individuals with higher quintiles demonstrated significantly higher risks for NAFLD (hazard ratio [HR] 1.48, 95%CI 1.31-1.67 for quintile 2; HR 2.07, 95%CI 1.85-2.33 for quintile 3; HR 2.55, 95%CI 2.27-2.88 for quintile 4). Similarly, high cumulative remnant-C quintiles were significantly associated with higher risks for NAFLD (HR 3.43, 95%CI 1.95-6.05 for quintile 2; HR 4.25, 95%CI 2.44-7.40 for quintile 3; HR 6.29, 95%CI 3.59-10.99 for quintile 4), compared with the quintile 1.@*CONCLUSION@#Elevated levels of baseline and cumulative remnant-C were independently associated with incident NAFLD. Monitoring immediate levels and longitudinal trends of remnant-C may need to be emphasized in adults as part of NAFLD prevention strategy.

Relationship between solar greenhouse working and anisometropia / 环境与职业医学

Background Due to long working time and complex and changeable lighting conditions, greenhouse workers' anisometropia is an issue of concern. Objective This study is conducted to evaluate the relationship between solar greenhouse working and anisometropia of workers. Methods Subjects of a solar greenhouse group and a non-greenhouse group in northwest area of China were selected. Questionnaire survey was used to collect general demographicinformation. Standard Logarithmic Visual Acuity Chart (GB 11533—2011) was used to measure naked eye vision before working, the absolute value of binocular visual acuity difference was calculated and converted into classification variables, and both anisometropia absolute value and classification variables of anisometropia were used as indicators to compare the difference of the two groups. A cumulative exposure index that multiplies exposure time and number of greenhouses was further introduced to evaluate cumulative exposure levels of the greenhouse workers and was used to divide them into low, medium, and high cumulative exposure subgroups. Generalized linear model and logistic regression model were used to analyze possible risk factors associated with anisometropia. Results A total of 1002 subjects were enrolled in this study, including 739 workers in the greenhouse group and 263 workers in the non-greenhouse group. The medians (interquartile intervals) of anisometropia of the greenhouse group and non-greenhouse group were 0.1 (0, 0.2) and 0 (0, 0.1) respectively, and the difference was statistically significant (P<0.05). The proportions of anisometropia=0, ≤0.2, and >0.2 in the greenhouse group were 34.2%, 55.2%, and 10.6%, respectively, and those in the non-greenhouse group were 58.2%, 34.6%, and 7.2%, respectively. The difference of anisometropia distribution between the two groups was statistically significant (P<0.05). According to the cumulative exposure index, the greenhouse group was divided into low, medium, and high cumulative exposure subgroups, with 154 (21.0%), 188 (25.6%), and 392 (53.4%) workers, respectively. There was no statistical significance in anisometropia among workers with different cumulative exposure levels (P>0.05). The results of multiple generalized linear analysis showed that greenhouse working was a risk factor of anisometropia (b=0.053, P<0.05), and the results of multiple logistic regression analysis showed that greenhouse working was associated with an increased risk of anisometropia (OR=2.586, 95%CI: 1.473-4.539). The results of multiple generalized linear analysis showed that medium exposure level increased the degree of anisometropia after adjusting age, gender, and other factors (b=0.054, P<0.05). Conclusion Solar greenhouse working may be a risk factor for increasing anisometropia in workers.

Prevalence characteristics and influencing factors of work-related musculoskeletal disorders in solar greenhouse workers / 环境与职业医学

Background In the process of greenhouse working, labor intensity is high and repetitive work involves multiple body parts such as limbs, neck, upper back, and lower back. The prevalence and comorbidity of work-related musculoskeletal disorders (WMSDs) in greenhouse workers are worthy of attention. Objective This study is conducted to investigate the prevalence and comorbidity, as well as potential influencing factors of WMSDs in greenhouse workers. Methods A total of 722 greenhouse workers were selected as the subjects for a cross-sectional epidemiological survey. Through questionnaire survey and physical examination, basic information of the subjects and the prevalence of WMSDs were collected. The participants were divided into low, medium, and high cumulative exposure groups by cumulative exposure index matrix. Chi-square test was used to analyze the difference of prevalence among different cumulative exposure levels, the correlation between the prevalence of WMSDs in paired sites was calculated as prevalence ratio (PR) by using the log-binomial model, the prevalence of multi-site WMSDs in each group was compared by Wilcoxon rank sum test, and the influencing factors of multi-site WMSDs were evaluated by multi-classification logistic regression model. Results The prevalence rate of WMSDs in the greenhouse workers was 78.7% (568/722). The main affected sites of body were lower back, legs, neck, and shoulders, and associated prevalence rates were 47.6%, 46.0%, 27.1%, and 23.8%, respectively. By constructing a cumulative exposure index matrix, the low, medium, and high cumulative exposure groups contained 121, 196, and 405 workers respectively. The prevalence rates of WMSDs in lower back, legs, or shoulders were significantly different among groups with different exposure levels (P<0.05), and the prevalence rates increased with higher cumulative exposure levels (lower back, \begin{document}${χ} _{{{\rm{trend}}}}

Effect of occupational high temperature exposure on type 2 diabetes in male steel workers / 中国职业医学

OBJECTIVE: To explore the effect of occupational high temperature exposure on type 2 diabetes( T2 DM) in male steel workers. METHODS: A cluster random sampling method was used to select 684 male steel workers,who exposed to occupational high temperature in a steel enterprise in Tangshan City,as the high temperature group,and 1 153 male steel workers without occupational high temperature exposure as the control group. The high temperature level of workers in these two groups was measured. The cumulative exposure( CE) of high temperature was calculated,and occupational health exam was performed. The multivariate logistic regression analysis and restricted cubic splines were used to analyze the relationship between high temperature CE and T2 DM. RESULTS: The prevalence of T2 DM in high-temperature group was higher than that in the control group( 13. 0% vs 7. 9%,P < 0. 05). The multivariate logistic regression analysis results showed that the risk of T2 DM in the high temperature group was higher than that in the control group after adjusting for age,body mass index,smoking,drinking,physical exercise and parents with diabetes( P < 0. 05). The 95% confidence interval was 1. 65( 1. 17-2. 33). Restricted cubic spline analysis showed that the high temperature CE was correlated with the prevalence of T2 DM in workers( P < 0. 01) and showed a linear correlation( nonlinearity test,P > 0. 05). CONCLUSION: Occupational high temperature exposure is associated with the occurrence of T2 DM in male steel workers. The male steel workers with high temperature CE show high prevalence of T2 DM risk.

Association between cumulative exposure to blood pressure and new-onset chronic kidney disease / 中华肾脏病杂志

Objective To investigate the association between cumulative exposure blood to pressure (cum BP) and new-onset chronic kidney disease (CKD).Methods In this prospective cohort study,101 510 employees of Kailuan Group receiving annual health examination during 2006 to 2007 were observed.The participants received the second,third,and fourth annual health examinations during 2008 to 2009,2010 to 2011,and 2012 to 2013 year respectively.Their urinary and serum creatinine were tested,and participants with incomplete SBP,DBP data and CKD were excluded.Further excluding those who somehow failed to take annual health examination,with incomplete data,or new-onset CKD 27 809 participants were selected in the analysis.According to cum BP exposure quintile grouping:Q1 ＜ 3.70 scores;Q2:3.70-6.16 scores;Q3:6.17-8.45 scores;Q4:8.46-10.95scores;Q5 ≥ 10.96 scores.Multivariate Logistic regression was used to analyze the association between cum BP level and new-onset CKD by cum BP exposure quintile grouping.Results The rise of cum BP exposure level caused the increased incidence of CKD.The incidences of CKD in the five quintile groups were 2.59％,3.11％,4.19％,5.81％,and 7.73％ respectively (P＜ 0.01).Compared with Q1 group,multivariate logistic regression analysis showed that after the adjustment of age,gender,education,income,smoking,drinking,BMI,FBG,TC,TG,LDL,HDL,UA and CRP,the incidences of CKD gradually increased in the Q2,Q3,Q4,and Q5 cum BP quintile groups,and OR(95％CI) values were 1.08(0.86-1.35),1.26(1.01-1.58),1.57(1.27-1.95),1.78(1.43-2.21) respectively (P for trend ＜0.01).Similar results were obtained in different genders.For each single point increase of cum BP exposure level,the incidence of CKD increased 6％ in the general population (P for trend ＜ 0.01),increased 8％ in male (P for trend ＜ 0.01),and 3％ in female (P for trend=0.12).Conclusion As the cumulative exposure to blood pressure increases,the risk of CKD incidence rises,especially in men.

Carbon disulfide exposure estimate and prevalence of chronic diseases after carbon disulfide poisoning-related occupational diseases

BACKGROUND: In Korea, Carbon disulfide (CS2) toxicity was an important social problem from the late 1980s to the early 1990s but there have been few large-scale studies examining the prevalence of diseases after CS2 exposure discontinuance. So we investigated past working exposure to CS2 characteristics from surviving ex-workers of a rayon manufacturing plant including cumulative CS2 exposure index. Furthermore, we studied the prevalence of their chronic diseases recently after many years. METHODS: We interviewed 633 ex-workers identified as CS2 poisoning-related occupational diseases to determine demographic and occupational characteristics and reviewed their medical records. The work environment measurement data from 1992 was used as a reference. Based on the interviews and foreign measurement documents, weights were assigned to the reference concentrations followed by calculation of individual exposure index, the sum of the portion of each time period multiplied by the concentrations of CS2 during that period. RESULTS: The cumulative exposure index was 128.2 ppm on average. Workers from the spinning, electrical equipment repair, and motor repair departments were exposed to high concentrations of ≥10 ppm. Workers from the maintenance of the ejector, manufacturing of CS2, post-process, refining, maintenance and manufacturing of viscose departments were exposed to low concentrations below 10 ppm. The prevalence for hypertension, coronary artery disease, cerebrovascular disease, diabetes, arrhythmia, psychoneurotic disorder, disorders of the nervous system and sensory organ were 69.2%, 13.9%, 24.8%, 24.5%, 1.3%, 65.7%, 72.4% respectively. CONCLUSIONS: We estimated the individual cumulative CS2 exposure based on interviews and foreign measurement documents, and work environment measurement data. Comparing the work environment measurement data from 1992, these values were similar to them. After identified as CS2 poisoning, there are subjects over 70 years of average age with disorders of the nervous system and sensory organs, hypertension, psychoneurotic disorder, cerebrovascular disease, diabetes, coronary artery disease, and arrhythmia. Because among ex-workers of the rayon manufacturing plant, only 633 survivors recognized as CS2 poisoning were studied, the others not identified as CS2 poisoning should also be investigated in the future.

Determination of Chlorinated Persistent Organic Pollutants in Infant Hair by Gas Chromatography_High Resolution Mass Spectrometry / 分析化学

Infant hair is a good medium to assess the cumulative exposure level of infant in the mother ' s body. Chlorinated persistent organic pollutants were ubiquitous and with the highest volume concentration in the human body. In this experiment, 20 infant hairs were collected from Beijing. The sample was overnight incubated in HCl, extracted with the mixture of hexane and dichloromethane, and cleaned up by a cartridge filled with alumina and acidified silica. The final eluate was concentrated, and 16 kinds of typical chlorinated persistent organic pollutants were detected with gas chromatography_high resolution mass spectrometry ( HRGC_MS). The results showed that the detection limit of the target compounds in sample was 1. 00-2. 50 μg/kg, the recovery of surrogate in all samples was more than 67 . 6%, and the range of recoveries for target compounds in spiked sample was 62. 5%-92. 3%. The positive rate is 100% for hexachlorobenzene,β_HCH and p, pˊ_DDE, 85% for γ_HCH, 50% for PCB28, and 40% for PCB52. The concentrations of Hexachlorobenzene, HCHs, DDTs and PCBs were 5. 48-8. 40 μg/kg, 3. 86-27. 1 μg/kg, 1. 16-18. 3 μg/kg and 2. 20-22. 1 μg/kg, respectively. The average concentrations were 7. 84 μg/kg for hexachlorobenzene, 6. 93 μg/kg for HCHs, 5. 53 μg/kg for DDTs, and 3. 44 μg/kg for PCBs. The method and the analysis results can be used to evaluate the accumulation level and cumulative exposure level of 16 target compounds for fetal in motherˊs body.

Acquried Dyschromatopsia in Women Workers in Shoe Manufacturing Who were Exposed to Organic Solvents / 대한산업의학회지

OBJECTIVES: This study was undertaken to investigate the relationship between color vision defects and occupational exposure to mixed organic solvents in women workers who were engaged in the shoe manufacturing industry. METHODS: A total of 173 women workers were involved in this study, 85 of whom were exposed to mixed organic solvents and were defined as the exposed group, and 88 workers comprised the non-exposed control group. The patients were questioned as to their drinking history, the year in which they were exposed and whether they had eye symptoms of blurred vision, eye fatigue, and eye irritation. The exposed workers in the shoe manufacturing factory were engaged in 3 work areas which were pasting, trimming, and cleaning. Their Color vision was assessed using the Hahn's double 15 hue test under standard illumination and their current and cumulative exposure levels were measured. RESULTS: The prevalence of color vision defect was 21.2% in the exposed group and 8.0% in the control group, and the blue-yellow defect was found to be 5.9 % in the exposed group. The logistic regression for the acquired dyschromatopsia and color confusion index showed that there were no variables that had significant relationships. Eye symptoms were more frequently developed in the exposed group. CONCLUSIONS: There is a possibility of developing color vision defects when workers are exposed to mixed organic solvents. However, the results of the color confusion index showed that there was no significant relationship to the cumulative exposure level, because of the low exposure level and high occupational turn over rate of the workers. Because the workers in the present study were exposed to low level solvents it will be necessary to study workers exposed to higher levels of organic solvents.

The Association of Exposure to Organic Solvents with Liver Function / 대한산업의학회지

OBJECTIVES: This study was conducted to evaluate the association of cumulative exposure to organic solvent with liver function. METHODS: We conducted a cross sectional study. 461 male workers who perform painting job at a shipyard and use organic solvents routinely and 125 workers of the same shipyard who never have been exposed to organic solvents were studied. All subjects who were confirmed not having HBsAg surveyed their age, BMI(body mass index), alcohol drinking and smoking history, and examined liver function test (SGOT, SGPT, gamma-GTP, Total protein, albumin, total bilirubin, direct bilirubin). The amount of cumulative exposure (CE) to mixed organic solvents were measured by biological monitoring method using their metabolites in urine. RESULTS: The CE was observed as a significant variable with logistic regression analysis on abnormality of SGOT(>35IU/L), SGPT(>40IU/L) and gamma-GTP(>63IU/L), their odds ratio were 1.10 (95 %CI, 1.02-1.20), 1.10 (95 %CI, 1.01-1.19), and 1.10 (95 %CI, 1.01-1.19) each. CONCLUSIONS: Therefore we suggest that the cumulative exposure to mixed organic solvents might be a significant variable on abnormal liver function indices (SGOT, SGPT,gamma-GTP) in male shipyard workers

The relationship between the utilization of health center and exposed amount to solvent by using cumulative exposure index / 예방의학회지

This study was conducted in order to clarify the factors affecting the number of utilization to health center for the shipyard workers who have been work in exposed environment to solvent. At first the tendencies of the number of utilization to health center in accordance with cumulative exposure(CE), lifetime weighted average exposure(LWAE), one's place of duty, work contents, states of using safety apparatus, the degree of the knowledge on handling solvents, exposure year. 1) The increase in the cumulative exposure(CE) was significantly higher in the number of utilization to health center. The group with longer exposure year showed significantly higher number of utilization to health center(p<0.01). Considering the work contents such as power blasting, spray, mixing and touch-up, the group of touch-up showed higher number of utilization to health center and this difference was statistically significant(p<0.001). Those who were not using the safety apparatus, showed higher number of utilization to health center, which was statistically significant(p<0.05). The degree of the knowledge on handling the solvent had no relation with using health center. 2) The results conducted from this study by multiple regression analysis in clarifying the factors affecting the number of utilization to health center, CE, exposure year and using safety apparatus was significant factor in utilization of health center.

Manganese Concentration in Blood and Urine of Manganese Exposed Welding Workers / 대한산업의학회지

Blood and urine samples were taken from 447 welders exposed to manganese containing welding fumes and 127 office workers not exposed to welding fumes as a control. The air samples were analyzed by flame atomic absorption spectrophotometer (Varian 30A, Australia), and blood and urine samples were analyzed by flameless atomic absorption spectrophotometer(Z-8100, Hibachi, Japan). Data were evaluated in accordance with type of industry, smoking habits, and work duration. The results obtained were as follows: 1. The limit of detection(LOD) levels of manganese in blood and urine were 0.11 microgram/100ml of and 0.14 microgram/l, respectively. Our results of manganese concentration were shown within +/-2 standard deviation which was the upper and lower warning limit (UWL or LWL) on quality control chart. 2. The airborne concentrations of manganese in welding workplaces were 0.067 mg/m3 showing differences by type of industry ; 0.017 mg/m3 in automobile assembly and manufacturing industries, 0.084 mg/m3 in steel heavy industries and 0.180 mg/m3 in shipyards. 3. The blood manganese concentrations showed differences by type of industry showing the highest values of 1.70 microgram/100m1 in shipyards, 1.24 microgram/100m1 in automobile assembly and manufacturing industries and 1.11 microgram/100ml in steel heavy industries. Urinary manganese concentration corrected by urinary creatinine concentrations was 0.34 microgram/g creatinine in automobile assembly and manufacturing industries, 0.43 microgram/g creatinine in steel heavy industries and 0.48 microgram/g creatinine in shipyards. There were no difference urinary manganese concentrations by type of industry. 4. The overall blood manganese concentration was 1.26 microgram/100ml, and urinary manganese concentration was 0.35 microgram/g creatinine in welders. In contrast to these values, blood and urinary manganese concentrations were lower in control group showing 0.73 microgram/100m1, and 0.28 microgram/g creatinine, respectively. 5. Smoking habits did not seem to affect on blood and urinary manganese concentrations both in welders and office workers. 6. Blood manganese concentrations were significantly higher in welder who had worked longer than 10 years than in welder who had worked less than 10 years. 7. The blood manganese concentrations were significantly correlated to airborne manganese concentrations(r=0.318, n=64), work duration(r=0.425, n=538), and cumulative exposure indices(CEI) (r=0.354, n=64).

Assessment of Cadmium in Blood and Urine of Occupationally Exposed Workers and Renal Dysfunction by Cumulative Exposure Estimate / 대한산업의학회지

88 workers exposed to cadmium were examined at the 12 factories using or producing cadmium in order to know the present state of cadmium exposure and renal dysfunction in 1992. Cadmium in blood and in urine were measured and compared by the 3 exposure level of cadmium in air. Cadmium in blood of low, moderate and high exposure group were 2.5, 3,8 and 7.6 microgram/L, respectively. Cadmium in urine were 1.8(1.3), 3.8(2,6) and 7.9 microgram/L(6.1 microgram/g creatinine) , resrectively. However, there was no relationship between Urinary cadmium and beta(2)-microglobulin. Cumulative exposure estimate (CEE) was calculated by multiplying the mean ambient cadmium level of the factory and working duration. CEE has a high correlation with cadmium in blood and urine, but no relation to beta(2)-microglobulin. Because working durations were relatively shorter than European workers', the highest CEE was just 300 microgram. year/m(3), which was not enough to induce renal tubular dysfunction. This study, however, suggested the possibility that renal tubular dysfunction caused by cadmium could be happened in Korea in the near future.

Neurobehavioral Changes according to Cumulative Exposure of Complex Organic Solvents / 예방의학회지

A cross sectional study was performed to evaluate the neurobehavioral effects of chronic exposure of complex organic solvents, using NCTB(Neurobehavioral Core Test Battery) recommended by WHO(World Health organization). Forty female shoe factory workers and twenty-two controls matched with age were participated. The tests were performed in the morning before start of work, to exclude the effects of acute exposure. Workers were exposed mainly to toluene, methyl ethyl ketone, n-hexane, cyclo-hexane, dichloroethylene, trichloroethylene, benzene, xylenes etc. The ranges of present solvent exposure of hygienic effect were 0.46~0.71 in the process using adhesives indirectly, and 1.83-2.39 in the process using it directly. We reclassified the subjects, according to cumulative exposure. It showed significantly poorer performances in high exposed group on Santa Ana Dexterity and Benton visual Retention, compared with control group. After controlling confounder, the significances were still remained. But, further cohort studies, having the information of personal exposure dose from entering a factory, are required to clarify the effects of chronic exposure of complex organic solvents in relation to dose and duration of exposure.