Tzu-Chieh Chou

Varicella vaccination alters the chronological trends of herpes zoster and varicella.

Background Population studies on trends of varicella and herpes zoster (HZ) associated with varicella zoster vaccination and climate is limited. Methods This study used insurance claims data to investigate the chronological changes in incident varicella and HZ associated with varicella zoster vaccination. Poisson regression was used to estimate the occurrence of varicella associated with the occurrence of HZ and vice versa by year, season, sex, temperature, and sunny hours. Results The varicella incidence declined from 7.14 to 0.76 per 1,000 person-years in 2000–2009, whereas the HZ incidence increased from 4.04 to 6.24 per 1,000 person-years. Females tended to have a higher risk than men for HZ (p<0.0001) but not varicella. The monthly mean varicella incidence was the lowest in September (160 cases) and the highest in January (425 cases), while the mean HZ incidence was lower in February (370 cases) and higher in August (470 cases). HZ was negatively associated with the incidence of varicella before and after the varicella zoster vaccination (p<0.001), increased 1.6% within one week post-vaccination. The effect of temperature on HZ was attenuated by 18.5% (p<0.0001) in association with vaccination. The varicella risk was positively associated with sun exposure hours, but negatively associated with temperature only before vaccination. Conclusions The varicella vaccination is effective in varicella prevention, but the incidence of HZ increases after vaccination. HZ has a stronger association with temperature and UV than with seasonality while varicella risk associated with temperature and UV is diminished.

Elevated triglyceride and decreased high density lipoprotein level in carbon disulfide workers in Taiwan

Carbon disulfide (CS2) is a man-made product utilized primarily in the manufacture of viscose rayon. Overexposure to CS2 has been associated with an increase in coronary heart disease. The aims of this study were to examine the dose-response relationship of CS2 exposure and elevated lipid profile tests among CS2-exposed workers in Taiwan. A total of 132 workers were recruited from two viscose rayon plants. Air sampling was performed to determine the CS2 exposure of workers. Demographic data and work history were gathered by a standard self-administered questionnaire. Lipid profile tests were also performed by routine methods. The average CS2 exposure concentration was 50.6 ± 25.6 ppm (range: 24–127 ppm) in the high-exposure group, 12.9 ± 5 ppm (range: 5.2–22.3 ppm) in the mid-exposure group, and 3.5 ± 1.2 ppm (range 0.97–5.2 ppm) in the low-exposure group. There were 21 out of 33 (63.7%) elevated triglyceride levels among high-CS2-exposure workers, 27 out of 64 (42.2%) among the middle-CS2-exposure, and 14 out of 35 (40%) among low-CS2-exposure workers, respectively. Compared to the low-CS2-exposure workers, the age- and weight-adjusted odds ratios (and 95% confidence intervals) of the prevalence of elevated triglyceride value were 1.12 (0.5, 2.7) for middle-CS2-exposure workers, and 2.81 (1.02, 7.8) for high-CS2-exposure workers. There was a significant linear trend between CS2 exposure and the prevalence of elevated triglyceride value (P = 0.046) after adjusting for other factors. There was also a lower prevalence of elevated HDL level in high-CS2-exposure workers than low-CS2-exposure workers (15.2% versus 31.4%). Compared to the low-CS2-exposure workers, the age- and weight-adjusted odds ratio (and 95% confidence intervals) of elevated HDL level were 0.34 (0.1, 1.18) for high-CS2-exposure workers, which was borderline significant. In conclusion, this study suggests that elevated triglyceride level and decreased HDL level are associated with CS2 exposure. The study also suggests that exposure to CS2 (concentration >23.2 ppm, which was above the current TLV-TWA of 10 ppm) are significantly associated with increased risk and decreased protective effect for coronary heart disease.

Increased risk of cardiovascular events in patients with herpes zoster: A population‐based study

The association between herpes zoster and cardiovascular complications remains vague with limited study on the association between these two disorders. This study evaluated the risk of cardiovascular diseases in patients with herpes zoster. From insurance claims data of Taiwan, 19,483 patients with herpes zoster diagnosed in 1998–2008 and 77,932 subjects without herpes zoster were identified in this study. Both cohorts were followed up until the end of 2010 to measure the incidence of arrhythmia and coronary artery disease. The incidence rate ratio and adjusted hazard ratio (HR) of the cardiovascular complications with 95% confidence interval (CI) were estimated. The incidence of arrhythmia was 1.17‐fold greater in the herpes zoster cohort than in the non‐herpes zoster cohort (13.2 vs. 11.3 per 1,000 person‐years), with an adjusted HR of 1.16 (P < 0.01). The coronary artery disease incidence in the herpes zoster cohort was 1.16‐fold higher than that in the non‐herpes zoster cohort (9.02 vs. 7.83 per 1,000 person‐years), with an adjusted HR of 1.11 (P < 0.01). Over the stratified follow‐up years, adjusted HRs were 1.22 (95% CI = 1.12–1.34) for arrhythmia and 1.14 (95% CI = 1.02–1.28) for coronary artery disease within 2 years after herpes zoster diagnosis. The risk measured for these disorders declined over time. Comorbidities of hypertension, diabetes, and hyperlipidemia also contributed to these cardiovascular disorders with greater extent. It is concluded that the contribution of herpes zoster to the risk of arrhythmia and cardiovascular diseases is less strong than that of hypertension, diabetes, and hyperlipidemia. J. Med. Virol. 86:772–777, 2014.

The Association between Obstructive Sleep Apnea and Metabolic Markers and Lipid Profiles

Purpose The purpose of this study was to investigate the association between apnea-hypopnea index (AHI) and metabolic markers and whether the elevated risk of Metabolic Syndrome (MetS) is related to Obstructive Sleep Apnea (OSA). Methods This cross-sectional study recruited 246 male bus drivers from one transportation company in Taiwan. Each participant was evaluated by a polysomnography (PSG) test and by blood lipids examination. Severity of OSA was categorized according to the apnea-hypopnea index (AHI). Results The results showed that a 73.3% prevalence of MetS in OSA (AHI > 15) and a 80.0% prevalence of MetS in severe OSA (AHI > 30) were found. After adjusting for confounding variables, an increased level of Body-Mass Index (BMI) and two non-MetS cardiovascular risk factors, total cholesterol/HDL-C ratio and TG/HDL-C ratio was significantly associated with AHI in subjects with severe OSA. MetS was about three times to be present in subjects with severe OSA, even adjusted for BMI. Conclusions The findings showed a high prevalence of MetS in OSA among professional drivers, especially in the severe group category. BMI was the major contributing factor to OSA. However, the present study did not find a sensitive clinical marker of a detrimental metabolic profile in OSA patients.

Low-Density Lipoprotein Electronegativity Is a Novel Cardiometabolic Risk Factor

Background Low-density lipoprotein (LDL) plays a central role in cardiovascular disease (CVD) development. In LDL chromatographically resolved according to charge, the most electronegative subfraction–L5–is the only subfraction that induces atherogenic responses in cultured vascular cells. Furthermore, increasing evidence has shown that plasma L5 levels are elevated in individuals with high cardiovascular risk. We hypothesized that LDL electronegativity is a novel index for predicting CVD. Methods In 30 asymptomatic individuals with metabolic syndrome (MetS) and 27 healthy control subjects, we examined correlations between plasma L5 levels and the number of MetS criteria fulfilled, CVD risk factors, and CVD risk according to the Framingham risk score. Results L5 levels were significantly higher in MetS subjects than in control subjects (21.9±18.7 mg/dL vs. 11.2±10.7 mg/dL, P:0.01). The Jonckheere trend test revealed that the percent L5 of total LDL (L5%) and L5 concentration increased with the number of MetS criteria (P<0.001). L5% correlated with classic CVD risk factors, including waist circumference, body mass index, waist-to-height ratio, smoking status, blood pressure, and levels of fasting plasma glucose, triglyceride, and high-density lipoprotein. Stepwise regression analysis revealed that fasting plasma glucose level and body mass index contributed to 28% of L5% variance. The L5 concentration was associated with CVD risk and contributed to 11% of 30-year general CVD risk variance when controlling the variance of waist circumference. Conclusion Our findings show that LDL electronegativity was associated with multiple CVD risk factors and CVD risk, suggesting that the LDL electronegativity index may have the potential to be a novel index for predicting CVD. Large-scale clinical trials are warranted to test the reliability of this hypothesis and the clinical importance of the LDL electronegativity index.

Effect of hand dermatitis on the total body burden of chromium after ferrous sulfate application in cement among cement workers

Background:  Ferrous sulfate (FeSO4) added to cement has been used to reduce the prevalence of dermatitis in workers. However, the effect of dermatitis on the total uptake of chromium in cement with or without FeSO4 has not been previously explored.

Biological monitoring of carbon disulphide: kinetics of urinary 2-thiothiazolidine-4-carboxylic acid (TTCA) in exposed workers

The objectives of this study was to establish the kinetics of urinary 2-thiothiazolidine-4-carboxylic acid (UTTCA) for workers exposed to carbon disulphide (CS2) and to investigate the effects of volume and creatinine adjustment methods for urine measurement. Ten workers in the spinning department of a rayon factory were individually monitored for airborne CS2 concentrations, with consecutive urine samples collected for 24-38 hours after termination of exposure. The U-TTCA, urine volume and creatinine level were measured for each sample. First-order and biphasic kinetics were determined using the curve-fit method, for the measurement series. For the first-order kinetics linearity fit, statistically significant correlation coefficients of 0.74-0.98 and 0.86-0.99 were derived for the volume- and creatinine-adjusted methods, respectively. For the biphasic kinetics approach, the overall correlation coefficients were 0.544-0.999 and 0.171-0.999 for the first and second phases of the creatinine-adjusted method, respectively. A post-shift U-TTCA of 3.0 mg/g Cr. equivalent, 40% below the current BEI setting at nearly PEL exposed level, was found. In conclusion, first-order kinetic response was confirmed for U-TTCA. Both volume- and creatinine-based urine adjustment are satisfactory for TTCA assessment as a biomarker of individual CS2 exposure although the correlation for creatinine-based measurement was modestly superior to the volume-based analogue. Based on the results of this study, we recommend a re-evaluation of the current biological exposure index of 5 mg/g creatinine at a CS2 exposure level of 10 ppm.

Predictors for progression of sleep disordered breathing among public transport drivers: a 3-year follow-up study

STUDY OBJECTIVES Sleep-disordered breathing (SDB) is associated with an increased risk of motor vehicle crashes. This study aimed to understand SDB progression and related factors among professional drivers. METHODS A total of 524 professional male drivers from a transportation company were included in this study. These drivers completed overnight in-home pulse oximetry studies both in 2006 and in 2009. Participants with abnormal results (oxygen desaturation index [ODI] ≥ 10 events/h) comprised the SDB group. Data included questionnaire information on demographics, medical history, SDB symptoms, and anthropometric measurements. RESULTS A total of 318 male workers were recruited for further analysis. Fifty of these workers belonged to the SDB group. Workers with untreated SDB significantly progressed to a more severe state after three years. Baseline body mass index (BMI), baseline ODI, and change in BMI were all significant positive predictors of SDB progression (β = 0.823, 0.242, and 1.626; p = 0.047, 0.013, and 0.004, respectively). Compared with non-SDB drivers, SDB subjects showed a greater proportion of newly diagnosed cardiovascular disease (38.0%) at follow-up. CONCLUSIONS Untreated SDB was a gradually progressive disorder in professional drivers over a three-year period. Subjects with high BMI and moderate to severe SDB should be closely monitored to allow for early detection of worsening SDB. Weight control should be highlighted in the management of SDB. COMMENTARY A commentary on this article appears in this issue on page 409.

Assessment of Airborne and Dermal Exposure to 2-Ethoxyethyl Acetate in an Occupational Environment

BACKGROUND Because of its chemical-physical properties, 2-ethoxyethyl acetate (EEAc) can penetrate through the skin. However, no actual occupational environmental studies or empirical dermal exposure measurements have been performed. METHODS Twenty workers from a commercial label silk screening shop were recruited and they completed a questionnaire of demographic information. Environmental monitoring of EEAc exposure via respiratory and dermal routes was performed for five consecutive working days. RESULTS Airborne EEAc concentration was over the permissible exposure limit of 5 ppm in 90% of the participants. The dermal EEAc concentration was highest on the palms. The EEAc concentration correlated with skin exposure level (P < 0.001). The dermal EEAc concentrations in individuals who did not wear gloves were higher than in those who wore gloves. CONCLUSIONS EEAc on the skin is strongly associated with airborne EEAc. Wearing impermeable gloves during high-risk tasks (cleaning process) can reduce EEAc dermal exposure on the palms.

Electrocardiographic abnormality for workers exposed to carbon disulfide at a viscose rayon plant.

Objective: This study investigated electrocardiography (ECG) manifestations for male workers with carbon disulfide exposure at rayon manufacturing plants. Methods: A total of 251 men in the exposure group and 226 administrative clerks in the reference group received physical examinations and completed questionnaires. Results: The prevalence of ECG abnormalities was much higher in the carbon disulfide exposure group (25.9%, n = 65) than in the reference group (2.7%, n = 6), with an odds ratio (OR) of 12.8 (95% confidence interval [CI] = 5.4–30.2). The foremen were at the highest risk of abnormal ECG (OR = 20.6, 95% CI = 6.5–65.2), followed by filament-spinning workers (OR = 14.2, 95% CI = 5.7–35.3), viscose-manufacturing workers (OR = 11.3, 95% CI = 4.3–30.1), and carbon disulfide-manufacturing workers (OR = 8.1, 95% CI = 2.7–25.6). The multivariate logistic regression analysis based on cumulative exposure index also showed a dose–response relationship with the exposure, and the risk of ECG abnormality could be initiated at the exposure history of 31 to 57 year-ppm with an OR of 7.2 (95% CI = 1.5–36.7). Conclusions: In general, the ECG abnormalities observed in workers at the permissible exposure level of carbon disulfide implicate the importance of environmental control of the chemical and of workers’ education in exposure prevention at work.