Sang-Hwan Han

Osteoporosis in males is becoming an important health concern in an aging society. The aim of this study was to investigate the associations between cadmium exposure and osteoporosis by considering the effect of obesity in aged males using a representative sample of the Korean population. Using the fourth and fifth Korea National Health and Nutrition Examination Survey data, 1098 males over 50 years of age were analyzed. The blood cadmium concentration was measured. The bone mineral density in the total hip, femur neck, and lumbar spine was measured using dual-energy X-ray absorptiometry. T-scores to determine the presence of osteoporosis were calculated using a Korean reference. Subjects were stratified into two groups according to obesity status (body mass index 2 and ≥25 kg/m²). In comparison with obese subjects with blood cadmium 1.50 μg/L had odds ratios of 4.57 (95% confidence interval [CI] 1.49–14.01) and 5.71 (95% CI 1.99–16.38) at the femur neck and any site, respectively, after adjusting for potential confounders such as age, serum creatinine, vitamin D deficiency, smoking, alcohol drinking, and physical activity level. However, this association was not significant in non-obese males. In conclusion, the effect of cadmium on osteoporosis was different by obesity status in aged males.

The aim of this study was to examine the association between shift work and hyperuricemia among steel company workers. We examined 1,029 male workers at a Korean steel company between June 6 and June 28, 2013. We conducted anthropometric measurements, questionnaire surveys, and blood tests. Hyperuricemia was defined as a serum uric acid concentration of ≥7.0 mg/dL. Logistic regression analyses were performed. In the full model, analysis was adjusted for covariates including age, body mass index, lifestyle factors, and comorbidities. The odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated for all models. The participants included 276 daytime workers and 753 shift workers. Among daytime workers, 72 (26.1%) individuals had hyperuricemia, as did 282 (37.5%) individuals among shift workers (p <0.001). There was a statistically significant association between shift work and hyperuricemia. In the unadjusted model, the OR of shift work was 1.70 (95% CI 1.25-2.31) for hyperuricemia. In the full model, the OR of shift work was also statistically significant after adjustment for covariates (OR 1.41, 95% CI 1.02-1.96). Among male steel workers, a significant association between shift work and hyperuricemia was observed.

Uric acid concentration is known to increase the prevalence of metabolic syndrome by affecting its components, resulting in increased risk of cerebrovascular and cardiovascular diseases, and long-term lead exposure is known to affect this serum uric acid level. In this study, we aimed to examine the association between the causes of hyperuricemia and metabolic syndrome, and to determine whether an increased blood lead level affects hyperuricemia. Anthropometric measurements, surveys, and blood tests were conducted between May and June 2012 in 759 men working in the steelmaking process at a domestic steel company. Workers were divided into 2 groups according to the presence or absence of hyperuricemia, and an analysis was performed to examine its association with metabolic syndrome. In addition, the workers were divided into 3 groups according to the blood lead level to analyze the association between blood lead and hyperuricemia. The geometric mean (standard deviation) of the blood lead levels in the hyperuricemia group was significantly higher than that of the healthy group (3.8 [1.8] vs. 3.3 [1.8] μg/dL). The adjusted odds ratio for metabolic syndrome of the hyperuricemia group increased significantly to 1.787 (1.125-2.839) compared with the healthy group. In addition, the adjusted odds ratios for the occurrence of hyperuricemia in the tertile 2 (2.61-4.50 μg/dL) and tertile 3 groups (>4.50 μg/dL) according to blood lead level significantly increased to 1.763 (1.116-2.784) and 1.982 (1.254-3.132), respectively, compared with the tertile 1 group (< 2.61 μg/dL). Hyperuricemia is believed to function as an independent risk factor for metabolic syndrome, while lead seems to increase the serum uric acid level even at a considerably low blood level. Therefore, attention should be given to patients with hyperuricemia and metabolic syndrome who are prone to lead exposure, and a prospective study should be conducted to identify their causal relationship.

Objective: This study investigated the number of Korean adults who had a normal body mass index (BMI) but high body‐fat percentage (BF%) and determined their increased risk factors for cardiovascular diseases, including high blood pressure, hyperglycemia, and dyslipidemia.Design and Methods: This cross‐sectional study was based on 12,386 subjects (6,534 men and 5,852 women), with a normal BMI, between 30 and 49 years of age. Subjects were categorized into two groups by BF% (normal BF% group, BF% n = 1,572; 291 [4.5%] men and 1,281 [21.9%] women). Subjects with a high BF% had a significantly higher prevalence of high blood pressure (men only), hyperglycemia, and dyslipidemia. Multiple logistic regression analyses revealed that subjects with a normal BMI and high BF% had a 1.63 (adjusted odds ratio, 95% confidence interval: 1.21–2.19) in men and 1.56 (adjusted odds ratio, 95% confidence interval: 1.36–1.80) in women increased risk of one or more cardiovascular risk factors compared to subjects in the normal BMI and normal BF% group, even after adjusting for abdominal obesity.Conclusion: High BF% is associated with a high cardiometabolic risks, regardless of abdominal obesity, in normal‐weight Korean adults. Thus, follow‐up screening of those with a high BF% may be necessary to detect and prevent cardiometabolic diseases, particularly for women with a normal BMI.

A Case‐crossover Study of Transient Risk Factors for Occupational Traumatic Hand Injuries in Incheon, Korea: Won‐Jun CHOI, et al. Department of Ocean and Underwater Medicine, Maritime Medical Center, ROK Navy, Korea—Objectives: A casecrossover study was conducted to identify transient risk factors for occupational acute hand injuries.Methods: In total, 98 subjects were recruited from a hospital specializing in occupational accidents and trauma. Patients who had injured fingers, hands or wrists during work were interviewed within 30 days after their accidents.Results: The relative risks for each factor were as follows: 22.9 for unusual or malfunctioning machines (95% confidence interval [CI] 14.4–36.4), 3.3 for wearing gloves (95% CI 1.9–5.7), 5.7 for unusual tasks (95% CI 3.8–8.8), 12.1 for altered work methods (95% CI 8.4–17.6), 4.1 for rushing (95% CI 2.6–6.3), 12.9 for being distracted (95% CI 7.9–20.9), 1.2 for feeling ill (95% CI 0.4–3.6) and 1.0 for working overtime (95% CI 0.6–1.6).Conclusion: The results suggest that some transient risk factors were associated with occupational acute hand injuries. These risk factors are probably preventable, and modifying unsafe or unusual conditions is important to reduce occupational traumatic hand injuries.

Um IY, et al. Korean J Occup Environ Med. 2012 Dec;24(4):365-374. https://doi.org/10.35371/kjoem.2012.24.4.365

Kang Y, et al. Korean J Occup Environ Med. 2010 Mar;22(1):58-63. https://doi.org/10.35371/kjoem.2010.22.1.58

Objectives: The prevalence of musculoskeletal symptoms and related factors were investigated by a structured questionnaire among male steel workers at a large steel company in Korea including a number of aged employees and workers with prior acute injuries. Methods: Of an eligible 2,093 workers, 1,836 responded to the survey. Among 39 job groups, 8 major job groups (1,068 subjects) were selected to evaluate the potential risk factors of musculoskeletal symptoms. Results: The prevalence of musculoskeletal symptoms was 19.1% for the upper extremities, 7.6% for the back, and 7.7% for the lower extremities. Regardless of body part, the prevalence was 25.5%. In logistic regression analysis, among workers of 8 major job groups, those who experienced prior acute injuries were more likely to have musculoskeletal symptoms in the same region as that of the injury (for the upper extremities, odds ratio [OR] 2.19, 95% confidence interval [CI] 1.51-3.16; for the back, OR 7.35, 95% CI 4.01-13.48; for the lower extremities, OR 4.20, 95% CI 2.33-7.57), after adjusting for age, duration of employment, and job contents. Conclusions: The effect of job contents differed according to the presence of prior acute injury. Among workers with prior injuries, the relationship between job contents and musculoskeletal symptoms was not statistically significant in general. Among workers with no prior injuries, job contents was a significant variable for the musculoskeletal symptoms of the upper extremities and back, after adjusting for age and duration of employment. These findings suggest that prior acute injuries are a potential risk factor for musculoskeletal disorders in the workforce. More detailed and specific strategies for managing musculoskeletal disorders including prevention of musculoskeletal injuries is needed.

Choi WJ, et al. Korean J Occup Environ Med. 2008 Sep;20(3):205-214. https://doi.org/10.35371/kjoem.2008.20.3.205

Has developed and implemented a medical ethics course entitled, "Life and Society II". The course uses dilemma discussion based on medical case studies to allow students to develop their moral reasoning ability in both clinical and hospital settings. The course was developed by the faculty of medicine during the 1998-1999 academic years. The program was designed in a four-stage process: 1) learning objectives were identified, 2) contemporary controversies and relevant ethical issues were chosen based on relevance to modern medical practice, 3) a syllabus was drafted based on the aforementioned ethical issues and teaching methods appropriate for each issue were integrated into the syllabus, and 4) tutorial manuals were produced. The course was taught to 41 second-year premedical students and evaluated by student surveys. The learning goals were identified through both a literature survey of contemporary issues in medical ethics and an in-house survey of important content to teach in a medical ethics course. The curriculum was designed based on the identification of specific learning objectives per ethical issue, selection of appropriate materials and content, organization of dilemma scenarios and formulation of questions for discussion. The course was taught using a variety of teaching formats: dilemma discussions, seminars, tutorials, lectures, assigned readings and student presentations. Positive results were obtained from the student surveys: it was discovered that most students thought that the course's learning objectives were achieved. Furthermore, of all the teaching methods employed, most of our students felt that discussing dilemmas was the most effective method for developing moral reasoning ability.