Shift Work Is Associated with Metabolic Syndrome in Young Female Korean Workers / 가정의학회지

BACKGROUND: Shift work is associated with health problems, including metabolic syndrome. This study investigated the association between shift work and metabolic syndrome in young workers. METHODS: A total of 3,317 subjects aged 20–40 years enrolled in the 2011–2012 Korean National Health and Nutrition Examination Survey were divided into shift and day workers. We conducted a cross-sectional study and calculated odds ratios using multivariate logistic regression analysis in order to examine the association between shift work and metabolic syndrome. RESULTS: The prevalence of metabolic syndrome was 14.3% and 7.1% among male and female shift workers, respectively. After adjusting for confounding factors, shift work was associated with metabolic syndrome in female workers (odds ratio, 2.53; 95% confidence interval, 1.12 to 5.70). CONCLUSION: Shift work was associated with metabolic syndrome in young women. Timely efforts are necessary to manage metabolic syndrome in the workplace.

Comparison of the Serum Cholesterol, Insulin Resistance and Markers of Metabolic Syndrome Based on Hepatitis C Virus RNA / 農村醫學 地域保健

OBJECTIVES: We compared the difference of lipid, insulin resistance and metabolic markers based on HCV RNA in Korean adults. METHODS: This was a cross-sectional study of 222 subjects visited the health promotion center of Pusan national university hospital from 2004 to 2007. Subjects were anti-HCV antibody positive and were performed RT-PCR for HCV RNA. The HCV RNA (+) group were 85 subjects, HCV RNA (−) control group were 115 subjects, and the HCV RNA (−) but past positive group were 22 subjects. We performed anthropometry, anti-HCV, RT-PCR, plasma concentrations of insulin, total cholesterol, LDL-cholesterol, HDL-cholesterol, and triglyceride. RESULTS: BMI, waist circumference, blood pressure, fasting plasma glucose, triglyceride, HDL cholesterol, insulin resistance such as HOMA-IR and QUICKI were not significantly different between HCV RNA positive and negative groups. The serum total cholesterol and LDL cholesterol level were significantly lower in the HCV RNA positive group than in the negative group (186.24±37.63 vs 197.22±37.23 mg/dl, p=0.041, 111.66±34.06 vs 121.38±35.50 mg/dl, p=0.042). After adjusting age and sex, high total cholesterol (≥ 200mg/dl) (adjusted OR=0.51, 95%CI 0.28-0.94, p=0.03) and high LDL cholesterol (≥ 130mg/dl) (adjusted OR=0.46, 95%CI 0.24~0.87, p=0.02) were inversely associated with being HCV RNA positive (p<0.05). CONCLUSIONS: The serum total cholesterol and LDL-cholesterol level were significantly lower in HCV RNA (+) group than in HCV RNA (−) group, but not in HCV RNA (−) but past positive group. Prospective cohort studies are needed to clarify the relationship between HCV RNA and metabolic markers.

The Cumulative Recurrence Rate of Colonic Adenomatous Polyps After Colon Polypectomy in a Single University Hospital Health Check-up Examinees / 農村醫學 地域保健

OBJECTIVES: Colonoscopy is a popular tool for screening for colon cancer throughout the world. The incidence of polypectomy and follow-up colonoscopy are persistently increasing but the studies about follow-up test after polypectomy are still lack of its domestic sources. This study is designed to look into the recurrence rate of colon polyps and risk factors after polypectomy. METHODS: This is a retrospective study by reviewing medical charts of 147 patients who underwent polypectomy and follow-up colonoscopy from Jan. 2000 to Mar. 2008. The Kudo classification was used to describe the polyps found in the colonoscopy. The follow-up period was defined as the term between polypectomy and the first colonoscopy follow up. RESULTS: Seventy six point two percent of the enrolled patient were male and the mean age was 56.5 +/- 8.1. Mean follow-up period was 24.9 +/- 13.7 (6 - 65) months. The cumulative recurrence rate of 1 year was 11.6%. The rate of 2 years was 36.7% and that of 3 years was 55.8%. The number of polyps was the factor which statistically showed significant relation of its recurrence rate. The histological morphology characteristic of polyps could be one independent factor which may be associated to the recurrence of polyps. CONCLUSIONS: The importance of colonoscopy follow up after polypectomy was clearly emphasized through the cumulative recurrence rate of 55.8%. Therefore, there is a need for more domestic studies with a large number of patients about the recurrence of polyps after polypectomy.

Corrigendum: Suicide Rate Differences by Sex, Age, and Urbanicity, and Related Regional Factors in Korea / 예방의학회지

The funding acknowledgment in this article was omitted as published.

Suicide Rate Differences by Sex, Age, and Urbanicity, and Related Regional Factors in Korea / 예방의학회지

OBJECTIVES: Identify the characteristics related to the suicide rates in rural and urban areas of Korea and discover the factors that influence the suicide rate of the rural and urban areas. METHODS: Using the data on causes of death from 2006 to 2008, the suicide rates were calculated and compared after age-standardization based on gender, age group and urbanicity. And, in order to understand the factors that influence suicide rate, total 10 local characteristics in four domains - public service, social integration, residential environment, and economic status - were selected for multiple regression analysis. RESULTS: The suicide rates were higher in men than women, in rural areas than urban, and in older people than the younger. Generally, although there were variations according to age group and urbanicity, suicide rates were significantly related to residential environment and regional economic status but not related to regional welfare spending and social integration. In addition, the population over the age of 65 years, only regional economic status has significantly influence on their suicide rates. CONCLUSIONS: The influence of characteristics of regions on suicide rate is various by age-group, gender, and urbanicity. Therefore, in order to lower suicide rate and reduce the gap between regions, various approaches must be adopted by taking into account the socioeconomic characteristics of the regions.

Sex Differences in Lifestyle Factors of Metabolic Syndrome in Korean Adults

BACKGROUND: Metabolic syndrome is a major risk factor for cardiovascular disease. The combination of an aging population with a chronic diseased population is leading to an increase in the mortality rate due to cardiovascular diseases. The purpose of this study was to assess the prevalence of metabolic syndrome in the Korean population and to evaluate its related factors for sex differences. METHODS: From April 2007 to December 2008, a total of 2,729 volunteers aged 40-69 years living in Changwon city underwent a clinical examination at a hospital in Changwon, Korea. Metabolic syndrome was diagnosed following the criteria defined in Circulation 2009. The clinical examination included measuring anthropometric variables and cardiovascular risk factors, while lifestyle factors were assessed through a questionnaire. RESULTS: The prevalence of metabolic syndrome in our sampling pool was 25.2% with a break down by sex showing a rate of 30.2% in men and 22.2% in women. Related factors associated with metabolic syndrome common to both sex were age, self-health assessment, and alcohol consumption. Sleep duration seemed to be a related factor in men, while income, education, and menstruation status played significant roles in women. CONCLUSIONS: To better manage metabolic syndrome, men need to be educated on alcohol use and women of low socioeconomic status require particular attention as do the aging population and postmenopausal women.

Deprivation and Mortality at the Town Level in Busan, Korea: An Ecological Study / 예방의학회지

OBJECTIVES: Busan is reported to have the highest mortality rate among 16 provinces in Korea, as well as considerable health inequality across its districts. This study sought to examine overall and cause-specific mortality and deprivation at the town level in Busan, thereby identifying towns and causes of deaths to be targeted for improving overall health and alleviating health inequality. METHODS: Standardized mortality ratios (SMRs) for all-cause and four specific leading causes of death were calculated at the town level in Busan for the years 2005 through 2008. To construct a deprivation index, principal components and factor analysis were adopted, using 10% sample data from the 2005 census. Geographic information system (GIS) mapping techniques were applied to compare spatial distributions between the deprivation index and SMRs. We fitted the Gaussian conditional autoregressive model (CAR) to estimate the relative risks of mortality by deprivation level, controlling for both the heterogeneity effect and spatial autocorrelation. RESULTS: The SMRs of towns in Busan averaged 100.3, ranging from 70.7 to 139.8. In old inner cities and towns reclaimed for replaced households, the deprivation index and SMRs were relatively high. CAR modeling showed that gaps in SMRs for heart disease, cerebrovascular disease, and physical injury were particularly high. CONCLUSIONS: Our findings indicate that more deprived towns are likely to have higher mortality, in particular from cardiovascular disease and physical injury. To improve overall health status and address health inequality, such deprived towns should be targeted.

Health Behavior and Metabolic Syndrome / 가정의학회지

BACKGROUND: Life style has been shown to improve risk factors comprising the metabolic syndrome. Metabolic syndrome is a prime candidate for lifestyle modification utilizing the tools of exercise, nutritional therapy and so on. Therefore, we examined the prevalence of metabolic syndrome according to health behaviors. METHODS: A total of 1,240 adults were recruited into this cross-sectional study. The subjects were examined on body mass index, waist circumference, blood pressure, and lipid profile. Medical history was reviewed and daily calorie intake was examined by food frequency questionnaire. Six healthy behaviors, sleeping hours, smoking, drinking, exercise, calorie intake and body weight of subjects, were examined. Each healthy behaviors were categorized into three groups. Metabolic syndrome as diagnosed by ATP III criteria. RESULTS: The study subjects consisted of 57.1% men and 42.9% women. The prevalence of metabolic syndrome was 14.3%. The prevalence of metabolic syndrome was lower in the group with good healthy behaviors. The subjects with more good healthy behaviors had a lower prevalence of metabolic syndrome than those with less good healthy behaviors (0, 50.0%; 1, 41.0%; 2, 30.6%; 3, 13.8%; 4, 8.5%; 5, 5.3%; and 6, 4.3%). Relative to the subjects with high good health behavior score, those with low good health behavior score were at significantly increased risk of metabolic syndrome (odds ratio = 4.25, 95% CI 2.97-6.08). CONCLUSION: The subjects with much more good healthy behaviors had a substantially lower risk of being diagnosed with the metabolic syndrome compared to those with lesser good healthy behaviors. This finding suggests that lifestyle modification may be appropriate as the first-line intervention to metabolic syndrome.

Prevalence of Spondylolysis in Pre-employment Screening Examination

OBJECTIVE: In Korea, there appears to be an increase in the diagnosis of lumbar spine disorders recently. This trend has urged employers to screen new employees for this disorder. One of the methods for the investigation is the radiological examination of the lumbar spine. We studied the prevalence of spondylolysis according to age and sex with lumbar X-ray (anterior-posterior view and lateral view) of new employees in pre-employment screening examination. We also estimated the outbreak period of spondylolysis by analysing the prevalence rates at each age group, which were the results of our study. METHODS: We gathered the data of lumbar X-ray findings for new employees, who had recieved pre-employment screening examinations in the department of occupational and environmental medicine of Masan Samsung Hospital Korea during a period from January 1, 2002 to December 31, 2005. We analyzed the data to obtain the age and sex prevalence of spondylolysis and spina bifida. RESULTS: The prevalence of spondylolysis for the pre-employment screening examination was 5.9% (male 6.6%; female 4.3%) in this study. The prevalence of spondylolysis after adjusting age and sex was 9.0%. The prevalence of spondylolysis was positively correlated with age, and showed to be higher in female than male. Body mass index of spondylolytic subjects was higher than that of normal. The prevalence of spondylolysis was significantly higher in those with spina bifida than normal subjects. CONCLUSION: The prevalence of spondylolysis of the pre-employment screening examination was 5.9% in this study. The factors which relates with spondylolysis were age, BMI and the prevalence of spina bifida.

The Role of C-reactive Protein as a Inflammation-related Factor in Metabolic Syndrome / 가정의학회지

BACKGROUND: The metabolic syndrome has been known as the cluster of insulin resistance, dyslipidemia, hypertension, and abdominal obesity. There have been many studies about the inflammatory role in atherosclerosis and cardiovascular diseases, also. We aimed to elucidate the role of high sensitivity C-reactive protein (hs-CRP) as a inflammation-related factor in metabolic syndrome in Korean adults by correlation and factor analysis. METHODS: A cross sectional study was carried out in 1,512 men and 1,836 women (over 20 years old) who had an examination at a center for health promotion of an university hospital from May 2004 through March 2005. The NCEP-ATP III definition and Asian-Pacific adjusted criteria were used to obtain the metabolic syndrome group. And we evaluated the role and gender difference of hs-CRP in metabolic syndrome by correlation and factor analysis. RESULTS: In women, hs-CRP was statistically correlated with most metabolic variables, especially insulin resistance. In factor analysis, 3 factors (obesity, blood pressure, and insulin resistance) were obtained in men and 4 factors (obesity, blood pressure, insulin resistance, and dyslipidemia) in women, respectively. In women, hs-CRP was a part of dyslipidemia factor. CONCLUSION: In factor anaylsis of metabolic syndrome factors with hs-CRP, hs-CRP was not a significant factor in men, but was included as a part of dyslipidemia factor in women.

The Prevalence and Risk Factors of Overactive Bladder in Korean Children: A Comparative Analysis according to Definition / 대한비뇨기과학회지

PURPOSE: We wanted to estimate the prevalence and risk factors of overactive bladder(OAB) in Korean children who were 5-13 years of age, according to the definition of OAB. MATERIALS AND METHODS: A randomly selected cross-sectional study was conducted on 26 kindergartens and 27 elementary schools nationwide in Korea. There were 19,240 children; a parent was asked to complete the questionnaires, which included items about OAB and the children's voiding and defecating habits. OAB was defined as urgency with or without urge incontinence, and usually with an increased daytime frequency and nocturia(ICCS 2006, group A) or an increased daytime frequency(>8 times/day) and/or urge urinary incontinence with or without urgency (group B); its prevalence and associated factors were investigated. RESULTS: The response rate for the questionnaires was 85.84%. The overall prevalence of OAB was 16.59%(group A) and 18.79%(group B). For groups A and B, the prevalence of OAB decreased with age from 22.89% to 12.16% and from 40.44% to 9.60%, respectively(p=0.0001). The overall rate of wet and dry OAB was 26.97% and 73.03%, respectively. Compared to the normal group, the children with OAB had a higher prevalence of nocturnal enuresis(NE), constipation, fecal incontinence, a history of urinary tract infection and delayed bladder control in both groups A and B(p<0.05). The rate of increased daytime frequency and urge incontinence were 3.69% and 2.31%(p=0.009), and 26.97% and 14.78%(p=0.0001) in group A and for the non-OAB children, respectively; their prevalence in group A decreased with age from 5.04% to 3.06% and from 45.74% to 18.50%, respectively(p=0.0001). CONCLUSIONS: The overall prevalence of OAB in group A for Korean children 5-13 years of age was similar to that in group B. However, the range of prevalence in group B was much more variable than that in group A. NE, constipation, fecal incontinence, a history of urinary tract infection and delayed bladder control may be risk factors for OAB in children.

The Steroid Effect on the Blood-Ocular Barrier Change Induced by Triolein Emulsion as seen on Contrast-Enhanced MR Images

OBJECTIVE: The purpose of this study is to evaluate the effect of dexamethasone on the damaged blood-ocular barrier caused by triolein emulsion, using contrast-enhanced MR imaging. MATERIALS AND METHODS: An emulsion of 0.1-mL triolein in 20 mL of saline was infused into the carotid arteries of 32 cats, 12 cats were placed in the treatment group and 18 cats were placed in the Control group. Thirty minutes after the infusion of triolein emulsion, a set of orbital pre- and post-contrast T1-weighted MR images (T1WIs) were obtained. Infusion of 10 mg/kg dexamethasone into the ipsilateral carotid artery of each of the cats in the treatment group cats and 20 mL saline in each of the cats in the control group was given. A second set of pre- and post-contrast orbital T1WIs were obtained three hours following triolein emulsion infusion. Qualitative analysis was performed for the the anterior chamber (AC), the posterior chamber (PC), and in the vitreous humor of the ipsilateral and contralateral eyes. The signal intensity ratios of the ipsilateral eye over the contralateral eye were quantitatively evaluated in the three ocular chambers on the first and second set of T1WIs, and were then statistically compared. RESULTS: Qualitatively, the AC, the PC or the vitreous did not show immediate contrast enhancement on the first and the second set of post-contrast T1WIs. However, the AC and the PC showed delayed contrast enhancement for both groups of cats on the second pre-contrast T1WIs. No enhancement or minimally delayed enhancement was seen for the vitreous humor. Quantitatively, the signal intensity ratios in the PC of the treatment group of cats were statistically lower than the ratios of the control group of cats for the second set of T1WIs (p = 0.037). The AC and vitreous showed no statistically significant difference between the feline treatment group and control group (p > 0.05). CONCLUSION: Contrast-enhanced MR images revealed increased vascular permeability in the PC of the eye after infusion of triolein emulsion. Dexamethasone seems to decrease the breakdown of the blood-aqueous barrier in the PC.

Effectiveness and Complications of Combination Therapy with Interferon Alpha and Ribavirin in Patients with Chronic Hepatitis C / 대한소화기학회지

BACKGROUND/AIMS: The effectiveness of combination therapy with conventional or pegylated interferon alpha and ribavirin in patients with chronic hepatitis C is well understood. However, the profound investigation about complications of the treatment has been rarely reported in Korea, where patients have broader spectrum of disease manifestations. The aim of this study was to evaluate the effectiveness and complications of the combination therapy of interferon alpha and ribavirin in patients with chronic hepatitis C. METHODS: Two hundred and forty patients with chronic hepatitis C were included. All patients were treated with interferon alpha (3 million units thrice a week) in combination with ribavirin (800-1,200 mg, depending on body weight). Patients were treated for 6 or 12 months according to the genotypes (genotype 1; 12 months, non-1; 6 months). We retrospectively evaluated ETR (end of treatment response) and SVR (sustained virologic response) on the basis of intent-to-treat in patients completing the therapy. RESULTS: In 154 patients who had completed the therapy, ETR was 79.2% and SVR was 61.0%. Multivariate analysis showed that genotype and early virologic response at 3 months of treatment were indepedent predictive factors of SVR. Due to insufficient response, 11.3% of the patients discontinued the therapy. In addition, 24.5% of the patients prematurely discontinued the therapy due to adverse events including aggravated liver function (15.4%), failure to return (7.9%), and others (1.2%). Dose modifications of interferon alpha or ribavirin were required due to anemia (15.4%), neutropenia (8.8%), or thrombocytopenia (4.6%). CONCLUSIONS: The overall SVR of patients who had completed the combination therapy with interferon alpha and ribavirin was 61.0%. However, about one third of the patients discontinued the therapy prematurely due to insufficient response, adverse events and/or noncompliance.

Induction Chemotherapy of Docetaxel and Cisplatin for the Elderly Patients with Squamous Cell Carcinoma of the Head and Neck / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Although concurrent chemoradiotherapy (CCRT) has been considered as a standard treatment for locally advanced squamous cell carcinoma of the head and neck (SCCHN), this treament is associated with increased toxicities such as mucositis and dermatitis. As a result, the dose intensity can be reduced and interruptions of radiotherapy are more common for CCRT than for sequential treatment, especially for the elderly patients. This prospective study was performed to assess the efficacy and safety profiles of the induction chemotherapy of docetaxel and cisplatin for elderly patients with locally advanced SCCHN. MATERIALS AND METHODS: Patients over 65 years of age with locally advanced SCCHN were treated with docetaxel (70 mg/m(2)) and cisplatin (75 mg/m(2)) every 21 days. The chemotherapy consisted of two cycles with a third cycle that was administered to the responding patients. Patients who did not respond to initial chemotherapy underwent radiotherapy as a definitive local treatment. RESULTS: Fifty patients were enrolled in this study and 44 patients were assessable for response and toxicity. The overall response rate was 88%, 16 patients (36%) achieved a complete response and 23 patients (52%) achieved a partial response. After a median follow-up of 24 months (range: 9~38 months) the median disease free period and overall survival period had not yet been reached. The one year and two year survival rates were 89% and 70%, respectively. The most common grade 3/4 adverse event was neutropenia, which occurred in 33 patients (75%) and 4 patients had febrile neutropenia. CONCLUSION: Combination chemotherapy of docetaxel and cisplatin is an effective regimen with an acceptable safety profile as the induction treatment for elderly patients suffering with SCCHN.

Predictors of Lamivudine Resistance in Patients with Chronic Hepatitis B Virus Infection / 대한간학회지

BACKGROUND/AIM: Drug resistance is a major concern during nucleos(t)ide analogues therapy in patients with chronic hepatitis B virus (HBV) infections. The aim of this study was to measure the risk of lamivudine resistance provided for each predictive factor in patients with chronic HBV infections. METHODS: A total of 183 patients were analyzed among 315 patients with chronic HBV infections enrolled in a tertiary referral hospital between January 2001 and December 2003 on this retrospective cohort study. AST/ALT, HBeAg/anti-HBe, serum HBV DNA levels were tested for every 3 or 6 months. HBV DNA level was tested using Cobas Amplicor HBV Monitor test(TM). Viral breakthrough was defined as HBV DNA > or = 5 log10 copies/mL on two consecutive visits in patients who, on treatment, achieved HBV DNA < 5 log10 copies/mL. The risk of viral breakthrough was measured using Cox proportional hazards model for variables: age, sex, BMI (kg/m2), baseline ALT, HBeAg positivity, baseline HBV DNA level, serum HBV DNA level at 6 month of lamivudine therapy. RESULTS: The cumulative rates of viral breakthrough were 9.6%, 39.0%, 55.8% at 12, 24, 36 months, respectively. Serum HBV DNA level of 6 month of lamivudine therapy and presence of HBeAg were independent predictors for viral breakthrough. The relative risk was 1.43 (95% C.I. 1.09-1.89, P=0.010) for serum HBV DNA level at 6 months of lamivudine therapy and 1.77 (95% C.I. 1.06-2.95, P=0.029) for presence of HBeAg. CONCLUSIONS: Serum HBV DNA level at 6 months of therapy and HBeAg positivity were predictors of early lamivudine resistance in patients with chronic HBV infections. An alternate therapy should be considered when serum viral load is high at 6 months of lamivudine therapy.

Effect Assessment of Worksite-based, Post-examination, Health Care Management System / 대한산업의학회지

OBJECTIVES: This study was conducted to develop a worksite-based, post-examination, health care management system for continuous and systematic management of workers with hypertension, diabetes mellitus, hyperlipidemia, and abnormal LFT detected by periodic health examination and to assess the effectiveness such a system as an intervention study. METHODS: Study subjects were selected from workers with hypertension, diabetes mellitus, hyperlipidemia, and abnormal LFT according to the selection criteria. The intervention group, but not the control group, received medical treatment of disease, follow up examination, and health education which consisted of information about the disease and the importance of life-style modification through periodic interview using the resources of occupational health service center in the worksite. To assess the effectiveness of this system, we compared follow up examination data from the intervention group with periodic examination data from the worksite control group. RESULTS: In the intervention group a significant reduction trend was recorded for systolic and diastolic blood pressure, fasting blood sugar, postprandial 2 hour glucose, total cholesterol, triglyceride, LDL-cholesterol, AST, ALT, and gamma-GTP, and a rising trend for HDL-cholesterol. Significant group differences ware recorded for fasting blood sugar, postprandial 2 hour glucose, total cholesterol, AST, and ALT. CONCLUSIONS: The worksite-based, post-examination, health care management system was effective for the continuous and systematic management of workers who had abnormal findings detected by periodic health examination.

Report on the Patients Parents' Understanding and the Pediatricians' Understanding of Cryptorchidism: The Optimal Time for Surgical Correction / 대한비뇨기과학회지

PURPOSE: Cryptorchidism is a common congenital anomaly seen in urology practice, and early diagnosis and treatment plays an important role in the prognosis of the disease. This survey was performed to discover how many parents and primary care physicians understand cryptorchidism from the aspect of the optimal time for surgical correction. MATERIALS AND METHODS: 100 pediatricians and 200 parents of the patients who were operated on for treating cryptorchidism in Pusan National University Hospital (PNUH) between the years 2000 and 2004 were enrolled in this survey. We sent out survey letters and conducted individual counseling secessions with using questionnaires that consisted of 11 items for the parents and 12 items for the pediatricians. RESULTS: Most of the parents (62.7%) and a portion of the pediatricians (21.1%) preferred to operate beyond 2 years of age for treating cryptorchidism. For the pediatricians, there was no significant interconnection between the physicians' gender, the post-residentship interval, experience of employment, the practice duration, the necessity of hormonal therapy and the additional studies on the univariated and multivariated analyses (p>0.05). However, with a longer post-residentship interval and practice duration, the pediatricians tended to prefer delayed orchiopexy (p<0.05). For the parents, there was a significant relationship between paternal age, the parents' academic background and income level and the optimal operation time on both the univariated and multivariaged analyses (p<0.05). The younger parents, the more educated parents and the higher income parents showed earlier recognition of cryptorchidism and they preferred earlier orchiopexy (p<0.05). CONCLUSIONS: The education programs and public activities targeting on the parents and the primary care physicians should be emphasized for achieving a better therapeutic outcome of cryptorchidism.

The Association between Pneumoconiosis and Genetic Polymorphism of GSTM1, GSTT1, GSTP1, NAT2, CYP2E1 and CYP1A1 / 대한산업의학회지

OBJECTIVES: To investigate effects of genetic polymorphism of glutathione S-transferase M1 (GSTM1), glutathione S-transferase T1 (GSTT1), glutathione S-transferase P1 (GSTP1), N-acetyltransferase (NAT2), cytochrome P450 2E1 (CYP2E1) and cytochrome P450 1A1 (CYP1A1) on pneumoconiosis. METHODS: Eighty-five pneumoconiosis patients and 122 age and sex matched healthy controls were enrolled. Direct interview and standard questionnaire were conducted and the genotypes of GSTM1, GSTT1, GSTP1, NAT2, CYP2E1 and CYP1A1 were investigated using multiplex PCR or PCR-RFLP methods with DNA extracted from venous blood. The relationship was investigated between the severity of pneumoconiosis and the polymorphism of GSTM1, GSTT1, GSTP1, NAT2, CYP2E1 and CYP1A1, and also with various environmental factors including smoking. RESULTS: We observed a significantly higher rate of genetic polymorphism in pneumoconiosis patients than in normal subjects. The odds ratio (95% CI) of NAT2 was 2.09 (1.19-3.68). In addition, smoking was related significantly with pneumoconiosis (OR 2.89, 95% CI 1.40-5.95). In multiple logistic regression analyses, NAT2 and smoking were significant risk factors for the development of pneumoconiosis (OR 1.84, 95% CI 1.00-3.37; OR 2.98, 95% CI 1.40-6.35, respectively). The age of onset of the disease and smoking were significantly related with moderate or severe pneumoconiosis (OR 0.91, 95% CI 0.83-0.99; OR 6.94, 95% CI 1.54-31.30, respectively). However there was no significant difference between the rate of genetic polymorphism of GSTM1, GSTT1, GSTP1, CYP2E1 and CYP1A1 in the two groups. CONCLUSION: NAT2 genetic polymorphism was higher in pneumoconiosis patients than in normal subjects. The age of onset of the disease and smoking were significantly related with pneumoconiosis. However, the genetic polymorphism of GSTM1, GSTT1, GSTP1, CYP2E1 and CYP1A1 was not related with development or severity of pneumoconiosis.

Risk Factor Assessment Using Surface Electromyography and Electrogoniometer among Automobile Part Manufacturers / 대한산업의학회지

OBJECTIVES: As automobile part manufacturing is characterized by high speed and high repetition, observation methods which are usually utilized for static posture are inappropriate to evaluate musculoskeleatal risk factors. This study quantified the risk factors of musculoskeletal disorders on the forearm and suggested exposure limits by estimating the risk factors using surface electromyography (EMG) and electrogoniometer. METHODS: Ten percent of the total workers at 3 automobile part manufacturing factories were randomly selected, and 99 male workers were recruited as study subjects. The study was conducted during May 2003 to September 2004. The workers were equipped with electrogoniometers on the wrist and the elbow, surface EMGs on the skin of the flexor digitorum superficialis (FDS) and extensor carpi radialis (ECR) muscles, and the heart beat recorder during work as indicators of joint movement, local muscle tension and physical work load, respectively. RESULTS: After controlling for age, body mass index and job stress, wrist flexion maximum angle, FDS relative activity (RA) and ECR RA were significantly associated with forearm musculoskeletal symptoms. The odds ratios of the forearm were 5.0(95% CI: 1.1-22.7), 14.0(95% CI: 1.5-128.8) and 7.3(95% CI: 1.1-49.4) for wrist flexion maximum angle more than 76 degrees, FDS RA more than 2.8%, and ECR RA more than 3.5%, respectively. CONCLUSIONS: Joint angle and focal muscle activity were associated with forearm musculoskeletal symptoms. To reduce forearm musculoskeletal symptoms among automobile part manufacturers, the wrist flexion angle, and FDS and ECR activity need to be reduced below the guidelines recommended in this study.

Validity of the Energy Expenditure Prediction Program to Evaluate Energy Expenditure During Work / 대한산업의학회지

OBJECTIVES: The Energy Expenditure Prediction ProgramTM (EEPP) has been considered as a simple and quantitative method to evaluate physical work load. However, the adoption of EEPP directly to Korean workers is problematic because it was developed in a laboratory setting for Caucasians. Therefore, this study was conducted to validate EEPP for Korean workers. METHODS: The study subjects consisted of 60 workers from two factories. Cycle ergometer test was conducted to calculate physical work capacity, and heart rate monitoring was conducted to check heart rate during work. After observing the task, energy expenditure was estimated by EEPP. RESULTS: EEPP underestimated energy expenditure less than EEHR (energy expenditure checked by heart rate) did(p<0.0001). The factors effecting EEHR were EEPP and task type. After dividing the task into regular and irregular tasks, the irregular task had a larger difference between the values from the two methods. We provided task specific regression models between EEHR and EEPP. CONCLUSIONS: Because EEPP underestimated energy expenditure, it needs to be adjusted before use with Korean workers. It is suggested that different adjusting equations are formulated for regular and irregular tasks. Further study to develop a specific energy estimation model appropriate for Koreans is needed to obtain more precise estimation.