Blood levels of cadmium and lead in residents near abandoned metal mine areas in Korea.

We analyzed national data on blood lead levels (BLL) and blood cadmium levels (BCL) in residents living near 38 abandoned metal mining areas (n = 5,682, 18-96 years old) in Korea that were collected by the first Health Effect Surveillance for Residents in Abandoned Metal mines (HESRAM) from 2008 to 2011. The geometric mean BCL and BLL were 1.60 µg/L (95 % CI = 1.57-1.62 µg/L) and 2.87 µg/dL (95 % CI = 2.84-2.90 µg/dL), respectively, notably higher than levels in the general population in Korea and other countries. We found significantly higher BLL and BCL levels in people living within 2 km of an abandoned metal mine (n = 3,165, BCL = 1.87 µg/L, BLL = 2.91 µg/dL) compared to people living more than 2 km away (n = 2,517, BCL = 1.31 µg/L, BLL = 2.82 µg/dL; P < 0.0001) and to the general population values reported in the literature.

A cohort study of hyperuricemia in middle-aged South Korean men.

Few prospective studies have assessed the incidence and determinants of asymptomatic hyperuricemia in free-living populations. The authors' goals in this study were to estimate the incidence of hyperuricemia and quantify the dose-response relations of specific risk factors with hyperuricemia in middle-aged South Korean male workers. The authors followed a cohort of 10,802 hyperuricemia-free men aged 30-59 years, examining them annually or biennially at a university hospital in Seoul, South Korea, from 2002 to 2009. A parametric Cox model and a pooled logistic regression model were used to estimate adjusted hazard ratios for incident hyperuricemia (defined as serum uric acid level ≥7.0 mg/dL) according to prespecified risk factors. During 51,210.6 person-years of follow-up, 2,496 men developed hyperuricemia (incidence rate = 48.7 per 1,000 person-years, 95% confidence interval: 46.8, 50.7). The incidence of hyperuricema increased across baseline categories of age, body mass index, alcohol intake, blood pressure, metabolic syndrome, high-sensitivity C-reactive protein, triglycerides, gamma-glutamyltransferase, and fatty liver, whereas fasting glucose, estimated glomerular filtration rate, and high density lipoprotein cholesterol levels were inversely associated with incident hyperuricemia. Development of hyperuricemia, a very common outcome among apparently healthy South Korean men, was predicted by a variety of cardiovascular and metabolic risk factors, suggesting that lifestyle modification may help reduce the incidence of hyperuricemia.

Relationship between chronic kidney disease and risk of coronary heart disease in Korean men.

There have been many epidemiological researches of chronic kidney disease (CKD), accompanied by an increase in the incidence of coronary heart disease (CHD). However, as far as we know, little research has been done to examine the extent of the relationship between CKD and CHD as estimated by Framingham risk score (FRS) in Korean men. CKD was defined as either proteinuria or an eGFR of < 60 mL/min per 1.73 m(2). The FRS has been used to predict the 10-yr risk of coronary events and usually divided into three levels of risk < 10% (low), 10%-19% (intermediate) and ≥ 20% (high). We defined FRS ≥ 10% as more-than-a-moderate CHD risk group and FRS ≥ 20% as a high CHD risk group, respectively. After adjusting for covariates, multivariable-adjusted logistic regression analyses showed a strong statistical significant relationship between CKD and high risk of CHD (adjusted OR, 1.95 [95% CI, 1.32-2.87]). Dipstick urinalysis and eGFR can be readily measured in most clinical settings. The measurement of kidney function may represent a relatively inexpensive and efficient way to identify individuals at higher risk for CHD.

Apolipoprotein B is highly associated with the risk of coronary heart disease as estimated by the Framingham risk score in healthy Korean men.

The aim of this study was to examine the association between serum apolipoprotein B (apoB) and the risk of coronary heart disease (CHD) using Framingham risk score (FRS) in healthy Korean men. A total of 13,523 men without medication history of diabetes and hypertension were enrolled in this study. The FRS is based on six coronary risk factors. FRS ≥ 10% was defined as more-than-a-moderate risk group and FRS ≥ 20% as high risk group, respectively. The logistic regression analyses were conducted. When quartile 1 (Q1) set as a reference, in unadjusted analyses, the Q2, Q3, Q4 of apoB level had increased odds ratio (OR) for the risk of CHD in both more-than-a-moderate risk and high risk group, respectively. After adjusting for confounding variables, multivariable-adjusted logistic regression analyses showed a strong relationship between the quartiles of apoB level and more-than-a-moderate risk and high risk group, respectively. These associations were attenuated, but still remained statistically significant. ApoB is found to be independently related to the risk of CHD using FRS in healthy Korean men, and the link between apoB and the risk of CHD is dose-dependent.

Time-dependent association between metabolic syndrome and risk of CKD in Korean men without hypertension or diabetes.

BACKGROUND: The time-dependent association between metabolic syndrome and risk of chronic kidney disease (CKD) is not clear. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: The study cohort was composed of 10,685 healthy men without CKD, hypertension, or diabetes who participated in a health-checkup program at a large work site. PREDICTOR: Metabolic syndrome. OUTCOMES & MEASUREMENTS: CKD was defined as an estimated glomerular filtration rate (GFR) less than 60 mL/min/1.73 m(2). A standard Cox proportional hazards model and a time-dependent Cox model were used to calculate adjusted hazard ratios (HRs) in the CKD model. RESULTS: During 40,616.8 person-years of follow-up, 291 incident cases of CKD developed; 787 patients (7.4%) had metabolic syndrome at baseline and 1,444 (14.4%) developed incident metabolic syndrome during follow-up. After adjustment for age, baseline GFR, gamma-glutamyltransferase level, and uric acid level, metabolic syndrome at baseline was associated with a significantly increased risk of CKD (HR, 1.99; 95% confidence interval, 1.46 to 2.73). Metabolic syndrome over time as a time-dependent variable also predicted the development of CKD (HR, 1.83; [corrected] 95% confidence interval, 1.34 to 2.49) [corrected] The relationship between metabolic syndrome and incident CKD remained significant, even after further adjustment for the homeostasis model assessment of insulin resistance, high-sensitivity C-reactive protein level, current smoking, alcohol consumption, or regular exercise. In addition, there were graded relationships between number of metabolic syndrome traits or quintile of homeostasis model assessment of insulin resistance over time as a time-dependent variable and risk of CKD. Both increased triglyceride and low high-density lipoprotein cholesterol levels among metabolic syndrome traits were associated with significantly increased risk of CKD. These results were effectively unchanged, even after additional adjustment for incident hypertension and incident diabetes. LIMITATIONS: Estimated GFR was used instead of a directly measured GFR to define CKD. CONCLUSION: Metabolic syndrome is an independent risk factor for the development of CKD in Korean men without hypertension or diabetes, even with changes in status of metabolic syndrome over time.

Changes in body weight predict CKD in healthy men.

Several recent prospective studies have reported that obesity is associated with an increased risk for chronic kidney disease (CKD), but it is unknown whether weight gain increases the risk for CKD if one remains within the "normal" category of body mass index (BMI). We prospectively followed a cohort of 8792 healthy men who had no known risk factors for CKD and participated in a comprehensive health evaluation program at a large worksite. During 35,927 person-years of follow-up, 427 new incident cases of CKD (estimated GFR <64 ml/min per 1.73 m(2)) developed. Cox proportional hazards modeling revealed that in both the normal-weight and overweight groups, a U-shaped association between weight change categories and development of CKD was observed after adjustment for age, baseline GFR, baseline BMI, HDL, fasting blood glucose, uric acid, and exercise habits. The lowest risk for CKD was observed among those whose weight changed -0.25 to <0.25 kg/yr (P < 0.001 for quadratic term). Weight change as a time-dependent variable was significantly related to CKD incidence. These relationships remained significant even after further adjustment for Homeostasis Model Assessment of Insulin Resistance, high-sensitivity C-reactive protein, systolic BP, diastolic BP, metabolic syndrome, incident hypertension, or incident diabetes. In summary, increases in body weight are independently associated with an increased risk for CKD, even when the BMI remains within the normal range.

Risk factors for bone mineral density at the calcaneus in 40-59 year-old male workers: a cross-sectional study in Korea.

BACKGROUND: Few epidemiologic studies have attempted to investigate the prevalence and risk factors for osteopenia and osteoporosis in middle-aged Asian men. We performed this study to determine the prevalence and risk factors of osteopenia and osteoporosis in this population. METHODS: This cross-sectional study was conducted from March to July, 2004. The subjects were 2,073 males aged from 40 to 59 years in the KHNP (Korea Hydro & Nuclear Power) workplace-based cohort. Bone mineral density (BMD) was measured by peripheral, dual-energy, X-ray absorptiometry (DXA) at the calcaneus. Anthropometric and lifestyle factors were investigated using a standard, self-reported questionnaire. RESULTS: BMD was 0.60 +/- 0.09 g/cm2 (mean +/- standard deviation) and was negatively correlated with age (r = -0.18, P < 0.001), but positively correlated with waist-to-hip ratio (WHR; r = 0.15, P < 0.001), body fat (r = 0.10, P < 0.001), BMI (r = 0.35, P < 0.001), height (r = 0.26, P < 0.001), and weight (r = 0.43, P < 0.001). In multiple linear regression analysis, the independent determinants associated with BMD were increasing age (coefficient = -0.002, P < 0.001), physical activity (< or = 2/week vs. > or = 3/week; coefficient = 0.017, P < 0.001), WHR (coefficient = -0.796, P < 0.001), body mass index (BMI; coefficient = 0.023, P < 0.001) and smoking status (never vs. ever; coefficient = -0.018, P < 0.001). CONCLUSION: We suggest that BMD of the calcaneus is correlated negatively with exposure to smoke and increased WHR, but positively with regular exercise and increased BMI.

Radiation-related occupational cancer and its recognition criteria in South Korea.

Ionizing radiation is a well-known carcinogen, and is listed as one carcinogenic agent of occupational cancer. Given the increase in the number of workers exposed to radiation, as well as the increase in concern regarding occupational cancer, the number of radiation-related occupational cancer claims is expected to increase. Unlike exposure assessment of other carcinogenic agents in the workplace, such as asbestos and benzene, radiation exposure is usually assessed on an individual basis with personal dosimeters, which makes it feasible to assess whether a worker's cancer occurrence is associated with their individual exposure. However, given the absence of a threshold dose for cancer initiation, it remains difficult to identify radiation exposure as the root cause of occupational cancer. Moreover, the association between cancer and radiation exposure in the workplace has not been clearly established due to a lack of scientific evidence. Therefore, criteria for the recognition of radiation-related occupational cancer should be carefully reviewed and updated with new scientific evidence and social consensus. The current criteria in Korea are valid in terms of eligible radiogenic cancer sites, adequate latent period, assessment of radiation exposure, and probability of causation. However, reducing uncertainty with respect to the determination of causation between exposure and cancer and developing more specific criteria that considers mixed exposure to radiation and other carcinogenic agents remains an important open question.

Comparison of work-related musculoskeletal symptoms between male cameramen and male office workers.

BACKGROUND: Previous studies have classified cameramen's job as physiologically heavy work and identified the risk factors of work-related musculoskeletal disorders (WRMDs) in cameramen. However, those studies limited their research subjects to cameramen. In this study, we compared the frequency and severity of WRMDs between cameramen and office workers. METHODS: A total of 293 subjects working in four broadcasting companies in Korea were recruited. A questionnaire survey was conducted for a month, starting in October 2016. The subjects were divided into cameramen and office workers according to their occupation. We compared the frequency and severity of WRMDs and ergonomic risk assessment results between the two groups. RESULTS: The high-risk WRMD group had a higher proportion of cameramen than office workers. Moreover, the high ergonomic risk group also had a higher proportion of cameramen than office workers for WRMDs in the upper extremities and waist+lower extremities. In the multivariable-adjusted model comparing cameramen and office workers, the odds ratio (OR) with 95% confidence interval (95% CI) for high-risk WRMDs was 3.50 (95% CI: 1.92-7.72) for the upper extremities and 3.18 (95% CI: 1.62-6.21) for the waist and the lower extremities. The ORs by body parts were 3.11 (95% CI: 1.28-7.57) for the neck, 3.90 (95% CI: 1.79-8.47) for the shoulders, and 4.23 (95% CI: 1.04-17.18) for the legs and feet. CONCLUSIONS: Our study suggests that cameramen are at high risk of WRMDs. Workplace improvements and management of the neck, shoulders, and lower extremities, which are susceptible to WRMDs, are necessary to prevent musculoskeletal disorders among cameramen.

Hazards and health problems in occupations dominated by aged workers in South Korea.

BACKGROUND: South Korea's population is aging more rapidly than any other country. Aging of the productive population will lead to shortage of labor and the decreasing quality of the labor force in South Korea. South Korea needs health care strategies to support the establishment of work environments that are appropriate for elderly workers who have reduced physical capacity. This paper aims to identify occupations that are dominated by aged workers and assess the exposure to hazards and work-related health problems of aged workers in these occupations. METHODS: We identified the 20 occupations in South Korea that employ the most aged workers (at least 55 years-old), among all 149 occupations that are defined as minor categories (identified by three digits) by the Korean Standard Classification of Occupations (KSCO). Exposure to hazards and work-related health problems of individuals in these occupations were evaluated by analyzing the results of the fourth Working Conditions Survey of 2014. RESULTS: Among the 20 occupations that employ the most aged workers, 'Elementary Occupations', which the KSCO classifies as major category (9), had the largest proportion of aged workers. After this, there were five occupations of skilled manual workers and six occupations of skilled non-manual workers. Aged workers in elementary and skilled manual occupations reported frequent exposure to job-specific hazards, such as noise, vibrations, high and low temperatures, solvents, and chemicals. Relative to other workers, aged workers in the occupations reported more frequent exposure to ergonomic hazards, such as tiring or painful positions, carrying or moving heavy loads, and repetitive movements, and also reported more work-related musculoskeletal disorders and general fatigue. Injury due to accident was common in machinery-handling occupations. CONCLUSION: Job-specific hazards should be reduced to prevent occupation-related disorders in elementary and skilled manual occupations that are dominated by aged workers.

Independent association between glycated hemoglobin and arterial stiffness in healthy men.

AIMS/INTRODUCTION: Many studies have reported that high levels of glycated hemoglobin (HbA1c) are strongly associated with an increased risk of cardiovascular disease. Many researchers have not studied the association of HbA1c with various subclinical atherosclerosis phenotypes. We evaluated the impact of HbA1c on arterial stiffness and atherosclerosis in healthy Korean healthy men. MATERIALS AND METHODS: The study population included healthy adult men who participated in health check-ups. All participants fasted for at least 8 h before taking the blood sample for fasting blood glucose, HbA1c, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triglyceride. Arterial stiffness was measured using brachial-ankle pulse wave velocity. Hierarchical regression analysis allowed us to determine the relationship between brachial-ankle pulse wave velocity (baPWV) and potential risk factors for cardiovascular disease. RESULTS: Age and HbA1c were significantly related to baPWV, in model 1. In model 2, blood pressure was added to model 1. Systolic blood pressure was a more significant variable, which was more affected on baPWV than diastolic blood pressure. In the case of model 3, we included all variables regarding arterial stiffness. According to model 3, the most explainable variable was age, and then systolic blood pressure, body mass index and triglyceride, respectively. CONCLUSIONS: We analyzed the associations between HbA1c, which is one of the risk factors, and arterial stiffness independently. An arterial stiffness measurement using baPWV can show the level of severity of the arteriosclerosis. When the level of stiffness has been increased, we could assume that the risk of arteriosclerosis would be increased. It can also be related to the increase of the risk of cardiovascular disease.

Risk Factors for Progression of Early Age-Related Macular Degeneration in Koreans.

PURPOSE: To identify risk factors for the progression of early age-related macular degeneration (AMD) in Koreans. METHODS: This study was conducted at a health-screening center and followed a prospective cohort study design. Of 10,890 participants older than 50 years, 318 (2.92%) presented with early AMD. Among these 318 participants, we re-examined 172 participants after a mean duration of 4.4 years. Progression was defined by the Age-Related Eye Disease Study (AREDS) simplified AMD severity scale. Multivariable logistic regression was used to examine associations between AMD progression and baseline physical, demographic, behavioral, and ocular characteristics. RESULTS: Of the 172 participants with early AMD who were re-examined, 34 (19.8%) had progression. Multivariable analyses revealed that current smoking (odds ratio, OR, 7.0, 95% confidence interval, CI, 1.4-34.4, adjusted for age, alcohol consumption, body mass index, BMI, blood pressure, BP, total cholesterol, and high density lipoprotein, HDL, cholesterol) and hypertension (OR 10.3, 95% CI 1.9-55.7, adjusted for age, smoking status, alcohol consumption, BMI, total cholesterol, and HDL cholesterol) were independently associated with progression of early AMD. Additionally, the presence of a central drusen lesion within one-third disc diameter of the macula (age-adjusted OR 4.8, 95% CI 1.3-17.6) and 20 or more drusen (age adjusted OR 7.8, 95% CI 2.5-24.0) were independently associated with progression of early AMD. CONCLUSION: Current smoking, hypertension, central drusen location, and increasing number of drusen were associated with an increased risk of early AMD progression in Koreans.

Health care strategy for ensuring work ability in an aging Korea.

The rapid aging trend in South Korea will cause a growing shortage of labor and decreasing quality of the labor force. The purpose of this commentary is to recommend a health care strategy to maintain and promote the work ability of employees in an aging Korea. Strategies to promote the work ability require the collaboration of governmental agencies at the central and local levels. First, the common goal should be the reinforcement of follow-up measure in general medical examinations and the promotion of healthy lifestyles for workers. Second, collaborating activities should be performed among the Worker's Health Center, the Health Promotion Center, and community health centers. In conclusion, health care strategies for ensuring the work ability in an aging Korea require the collaboration of governmental agencies at the central and local levels.

Comparison of sleep quality based on direction of shift rotation in electronics workers.

BACKGROUND: Previous studies have reported the effects of direction of shift rotation on sleep, however, the findings are inconsistent. In this study, we investigated sleep quality related to direction of shift rotation using large-scale data from shiftwork-specific health examinations of electronics workers. METHODS: This study included 4750 electronics workers working in a rotating 3-shift system who completed a medical examination for shift workers survey from January 1 to December 31, 2014, at a general hospital. The subjects were categorized into one of two groups according to direction of shift rotation. We compared sleep quality index between the subjects who worked in forward rotation and backward rotation systems. RESULTS: Backward rotation was positively associated with prevalence of poor sleep quality. In the multivariable-adjusted model, when comparing backward rotation to forward rotation, the odds ratio (OR) with 95 % confidence interval (95 % CI) for poor sleep quality was 1.95 (1.58-2.41). After stratifying by gender, the ORs (95 % CIs) for poor sleep quality in male and female was 1.92 (1.47-2.49) and 2.13 (1.47-3.08), respectively. In subgroup analyses, backward rotation was significantly associated with poor sleep quality in workers ≥30 years of age compared with workers <30 years of age (adjusted OR 2.60 vs. 1.89, respectively; P for interaction <0.001). CONCLUSIONS: Our study supports that a backward rotation system is associated with poor sleep quality. Forward rotation systems should be considered to reduce sleep problems.

Risk factors of work-related upper extremity musculoskeletal disorders in male cameramen.

OBJECTIVE: The aim of this study is to determine the risk factors related to upper extremities work-related musculoskeletal disorders (WRMSDs) in cameramen. METHODS: A questionnaire survey was performed on 166 cameramen in a broadcasting station. The questionnaire consisted of questions on the general characteristics, the health behavior, work type and duration, physical burden, ergonomic posture, and musculoskeletal symptoms. Definition of musculoskeletal disorders was based on NIOSH criteria. RESULTS: The positive rate of WRMSDs symptoms by parts of the body was turned out to be the highest in the shoulder (14.5%) and the lowest in arm and elbow (6%). Logistic regression analysis revealed that symptoms in the shoulders increased with BMI (OR = 3.62, 95% CI = 1.03-12.71), physical burden (OR = 9.29, 95% CI = 1.72-61.78 in the very hard group) and ergonomic factors (OR = 4.50, 95% CI = 1.03-19.68). Ergonomic factors were only related to the symptoms of hand and wrist (OR = 10.21, 95% CI = 1.02-102.20). WRMSDs symptoms, in the whole upper extremities, were higher in the 50 or older age group (OR = 5.86, 95% CI = 1.03-33.26), higher BMI group (OR = 3.26, 95% CI = 1.28-13.53), non-exercise group (OR = 2.37, 95% CI = 1.24-12.59), high physical burden group (OR = 7.6, 95% CI = 1.34-52.74), and high grade ergonomic risk group (OR = 4.82, 95% CI = 1.29-16.06). CONCLUSION: The most serious musculoskeletal disorders of male cameramen were shoulder pain. Ergonomic factors and physical burden were the most significant factors affecting WRMSDs in cameramen in this study. Cameramen should be educated to be able to improve the ergonomic occupational environment and to set up preventive measures against the risk factors during work.

Association of cadmium with diabetes in middle-aged residents of abandoned metal mines: the first health effect surveillance for residents in abandoned metal mines.

OBJECTIVE: The aim of this study was to determine the association between urinary cadmium (U-cd) concentration and diabetes in middle-aged Korean residents of abandoned mines using the first Health Effect Surveillance for Residents in Abandoned Metal mines (HESRAM). METHODS: This study was cross-sectional study conducted on 719 residents between 40-70 years in 38 abandoned metal mines in Korea. Data was collected by HESRAM from 2008 to 2011. The correlation coefficient of U-cd and fasting blood glucose, odds ratio in urinary cadmium tertiles and diabetes prevalence was analyzed according to the sex category. RESULTS: The correlation coefficient U-cd concentration and fasting blood glucose was 0.182 in male. Logistic regression analysis in male revealed a third tertile odds ratio of U-cd (2 µg/g creatinine < U-cd) while diabetes prevalence was 1.81 (95 % CI 1.05-3.12) with adjusted age, BMI, smoking and alcohol consumption, region, family income. On the other hand, the odds ratio for third tertile of U-cd (3 µg/g creatinine < U-cd) between diabetes prevalence in female was 1.39 (95 % CI 0.52-3.72) in addition to adjusted menopausal status. CONCLUSIONS: Environmental exposure to cadmium in abandoned mine residents was associated with diabetes in male. Closed monitoring and periodic evaluation of the health effects of chronic environmental exposure on abandoned mines residents will be needed.

Increasing risk of diabetes mellitus according to liver function alterations in electronic workers.

AIMS/INTRODUCTION: We sought to determine the association between change in fasting plasma glucose (FPG) and levels of liver enzymes, such as aspartate transaminase, alanine transaminase and gamma-glutamyltransferase, from health examinations. MATERIALS AND METHODS: A total of 9,393 health screen examinees with no evidence of viral hepatitis, liver diseases, abnormal liver function and diabetes in their past disease history were enrolled in the present study. All the participants underwent three health examinations. Group 1 and 4 were stationary groups of those with normal liver enzyme levels in the first and second health examinations (G1), and abnormal liver enzyme levels in the first and second health check-up (G4). Groups 2 and 3 were altered groups of those with abnormal liver enzyme levels in the first health examination, which became normal in the second health examination (G2), and from a normal liver enzymes level to an abnormal liver enzymes level (G3). RESULTS: FPG levels were elevated in male participants (P < 0.01), and were related to old age (P < 0.01), drinking (P < 0.01), smoking (P < 0.01) and so on. There was a strong relationship between FPG levels in the last health examination and altered liver function enzyme levels from the first health examination to the second check-up. In other words, group 4 had the highest level of FPG compared with the other groups (G1 < G2 < G3). CONCLUSIONS: An association was observed between FPG levels and abnormal liver function in manufacturing workers. Abnormal liver function can be closely associated with the development of diabetes.

The Magnitude of Mortality from Ischemic Heart Disease Attributed to Occupational Factors in Korea - Attributable Fraction Estimation Using Meta-analysis.

OBJECTIVES: Ischemic heart disease (IHD) is a major cause of death in Korea and known to result from several occupational factors. This study attempted to estimate the current magnitude of IHD mortality due to occupational factors in Korea. METHODS: After selecting occupational risk factors by literature investigation, we calculated attributable fractions (AFs) from relative risks and exposure data for each factor. Relative risks were estimated using meta-analysis based on published research. Exposure data were collected from the 2006 Survey of Korean Working Conditions. Finally, we estimated 2006 occupation-related IHD mortality. RESULTS: FOR THE FACTORS CONSIDERED, WE ESTIMATED THE FOLLOWING RELATIVE RISKS: noise 1.06, environmental tobacco smoke 1.19 (men) and 1.22 (women), shift work 1.12, and low job control 1.15 (men) and 1.08 (women). Combined AFs of those factors in the IHD were estimated at 9.29% (0.3-18.51%) in men and 5.78% (-7.05-19.15%) in women. Based on these fractions, Korea's 2006 death toll from occupational IHD between the age of 15 and 69 was calculated at 353 in men (total 3,804) and 72 in women (total 1,246). CONCLUSION: We estimated occupational IHD mortality of Korea with updated data and more relevant evidence. Despite the efforts to obtain reliable estimates, there were many assumptions and limitations that must be overcome. Future research based on more precise design and reliable evidence is required for more accurate estimates.

Serum uric acid levels predict incident nonalcoholic fatty liver disease in healthy Korean men.

The objective of the study was to assess the prospective association between serum uric acid levels and incident nonalcoholic fatty liver disease in a cohort of healthy Korean men. A cohort study was performed on 5741 Korean men, 30 to 59 years of age, with no evidence of fatty liver disease on liver ultrasound and with no major risk factors for liver disease at baseline. Study participants were followed in annual or biennial health examinations between 2002 and 2008. The presence of fatty liver was determined at each examination by ultrasound. Cox proportional hazards models were used to evaluate the association of baseline and time-dependent levels of serum uric acid with incident fatty liver, adjusted for potential confounders. During 23,995 person-years of follow-up, 1717 participants developed fatty liver on ultrasound examination. After adjustment for age, body mass index, smoking, and alcohol intake, the hazard ratios (95% confidence intervals) for incident fatty liver comparing quartiles 2 to 4 of serum uric acid to quartile 1 were 1.17 (1.01-1.37), 1.28 (1.11-1.48), and 1.51 (1.31-1.73), respectively (P for trend = .001). The adjusted hazard ratio comparing participants with hyperuricemia (serum uric acid ≥7.0 mg/dL) to those with normouricemia (<7.0 mg/dL) was 1.29 (1.14-1.46). A graded and statistically significant association persisted after adjusting for other cardiometabolic factors and also in time-dependent models. Serum uric acid was an independent risk factor of incident fatty liver detected by ultrasonography. Additional research should clarify the mechanisms underlying this association and the role of hyperuricemia in the development of fatty liver.