• Journal of Preventive Medicine and Public Health
• /
• 제36권4호
• /
• pp.367-372
• /
• 2003

Objectives : There are many concerns about ginseng as a cancer chemopreventive substance, but there have been few epidemiological studies on ginseng, This study sought to examine the relationships between ginseng intake and cancer incidence in the Kangwha cohort. Methods ; Between March 1985 and December 1999, 2697 males, aged 55 or over, as of 1985, were followed up for their cancer incidence. The cancer incidence rate, standardized incidence ratio and risk ratios were calculated according to ginseng intake. A Cox proportional hazard model was used to adjust for age at entry, smoking, alcohol intake, hypertension, and body mass index. Results & Conclusions : The ginseng intake group had the same cancer (C00-C97) incidences (Standardized Incidence Ratio: SIR=1.11, 95% Confidence Interval=0.97-1.27) and the same risk ratio (RR=1.09, 95% Confidence Interval=0.85-1.41) as the no-intake group. Analyzing the subjects that had followed up from 1990, however, the ginseng intake group had lower cancer incidences at all sites (RR=0.79, 95% Confidence Interval=0.58-1.09). This was a cohort study to try and evaluate the association between ginseng intake and the incidences of cancer, The results of this study provide no clear conclusions on the cancer preventive effects of ginseng. Therefore, further study is needed in the future.

• 한국환경보건학회지
• /
• 제34권1호
• /
• pp.1-11
• /
• 2008

The purpose of this study was to investigate air quality in Chungju, Korea, using data obtained with a local air quality monitoring system. We have utilised cohort studies to investigate the relations between environmental pollution and the health of residents near large industrial complexes since 2004. This study analyzes the $O_3,\;NO_2,\;SO_2,\;CO\;and\;PM_{10}$ concentration in Chungju from 2002 to 2006. Air pollutants are closely related to the number of manufacturing facilities and cars, energy utilization and weather conditions. Generally, the diurnal concentration of air pollutants in Chungju reached the highest level in the morning (about$08:00{\sim}$) and early evening (about$19:00{\sim}$). On the other hand, the diurnal concentration of ozone as recorded gives the highest amount in late afternoon (about$16:00{\sim}$) and lowest in early morning (about$08:00{\sim}$). The concentration of air pollutants in Chungju was highest from winter to spring and lowest during the summer season. On the other hand, the monthly variation of ozone concentration was greatest in June and smallest in December. Also the, $PM_{10}$ concentration posted the highest record in April and the lowest during September. In general, this study analyzed air pollution changes in Chungju as well as in large scale industrial complex regions within Korea such as Ulsan, Pohang, Kwangyang, Sihwa Panwol and Gangneung in Korea. We compared the air quality of Chungju with those of these cites and found that air pollutants except for CO in Chungju was generally lower than large industrial complex regions.

• Journal of Periodontal and Implant Science
• /
• 제50권5호
• /
• pp.303-312
• /
• 2020

Purpose: The purpose of this study was to evaluate severe periodontitis with tooth loss as a modifiable risk factor for Alzheimer dementia (AD), vascular dementia (VaD), and mixed dementia (MD) using the National Health Insurance Service-National Health Screening Retrospective Cohort database with long-term follow-up over 14 years. Methods: Multivariate Cox hazards regression analysis was applied to a longitudinal retrospective database, which was updated in 2018, to evaluate the association between severe periodontitis with few remaining teeth and dementia after adjusting for potential risk factors, including sociodemographic factors and comorbid diseases. Results: Among 514,866 individuals in South Korea, 237,940 (46.2%) participants satisfying the inclusion criteria were selected. A total of 10,115 age- and sex-matched participants with severe periodontitis and 10,115 periodontally healthy participants were randomly selected and evenly assigned. The results showed that the risks of AD (hazard ratio [HR], 1.08), VaD (HR, 1.24), and MD (HR, 1.16) were significantly higher in patients with severe periodontitis with 1-9 remaining teeth after adjustment for sociodemographic factors, anthropomorphic measurements, lifestyle factors, and comorbidities. Conclusions: Severe periodontitis with few remaining teeth (1-9) may be considered a modifiable risk factor for the development of AD, VaD, and MD in Korean adults.

• Journal of Preventive Medicine and Public Health
• /
• 제41권1호
• /
• pp.45-50
• /
• 2008

Objectives : To determine the relationship between exercise and the incidence of type 2 diabetes in an impaired fasting glucose group. Methods : This prospective cohort study was conducted in 19,440 men and 4,297 women, aged 30-69 years, with impaired fasting glucose at baseline who had undergone biennial medical evaluation through the National Health Insurance Corporation from 2000 to 2004. Impaired fasting glucose was defined as fasting glucose of 100 to 125 mg/dl and the subjects were divided into 3 groups depending on weekly exercise frequency. Multivariate logistic regression analysis was used to evaluate the association between the baseline exercise status and incidence of type 2 diabetes. Results : During the 4-year follow-up, a total of 3,239 men and 283 women developed type 2 diabetes, a cumulative incidence of 16.6% for men, and 6.5% for women. Also, 1,688 men (21.2%) and 127 women (15.2%) developed type 2 diabetes in the obese group. The adjusted relative risk (RR) of developing type 2 diabetes in non-exercising men was significantly higher than exercising men regularly (RR= 1.375, 95% CI=1.236-1.529)(p<0.0001), and the RR for non-exercising women was higher than exercising women regularly (RR=1.124, 95% CI=0.711-1.778). The RR for non-exercise men/women in the obese group was 1.571 (95% CI=1.351-1.827)(p<0.0001)/1.869 (95% CI=0.846-4.130). Conclusions : Regular exercise is effective in preventing type 2 diabetes in people with impaired fasting glucose, and particularly in obese people. People with risk factors for diabetes should participate in a regular exercise program.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권7호
• /
• pp.4215-4221
• /
• 2013

Purposes: Lung cancer is prevalent worldwide and improvements in timely and effective diagnosis are need. Pentraxin-3 as a novel serum marker for lung cancer (LC) has not been validated in large cohort studies. The aim of the study was to assess its clinical value in diagnosis and prognosis. Methods: We analyzed serum PTX-3 levels in a total of 1,605 patients with LC, benign lung diseases and healthy controls, as well as 493 non-lung cancer patients including 12 different types of cancers. Preoperative and postoperative data were further assessed in patients undergoing LC resection. The diagnostic performance of PTX-3 for LC and early-stage LC was assessed using receiver operating characteristics (ROC) by comparing with serum carcinoembryonic antigen (CEA), cytokeratin 19 fragments (CYFRA 21-1). Results: Levels of PTX-3 in serum were significantly higher in patients with LC than all controls. ROC curves showed the optimum diagnostic cutoff was 8.03ng/mL (AUC 0.823, [95%CI 0.789-0.856], sensitivity 72.8%, and specificity 77.3% in the test cohort; 0.802, [95%CI 0.762-0.843], sensitivity 69.7%, and specificity 76.4% in the validate cohort). Similar diagnostic performance of PTX-3 was observed for early-stage LC. PTX-3 decreased following surgical resection of LC and increased with tumor recurrence. Significantly elevated PTX-3 levels were also seen in patients with non-lung cancers. Conclusions: The present data revealed that PTX-3 was significantly increased in both tissue and serum samples in LC patients. PTX-3 is a valuable biomarker for LC and improved identification of patients with LC and early-stage LC from those with non-malignant lung diseases.

• Journal of Korean Neurosurgical Society
• /
• 제63권6호
• /
• pp.730-737
• /
• 2020

Objective : Spinal degeneration is a progressive disease, worsening over time. Lumbar degenerative disease (LDD) is a major spinal disease in elderly patients. Surgical treatment is considered for medically intractable patients with LDD and reoperation after primary surgery is not uncommon. The surgical outcome is occasionally unpredictable because of comorbidities. In the present study, the relationship between comorbidities and the incidence of reoperation for LDD over time was determined. Methods : The claims data of the health insurance national database were used to identify a cohort of patients who underwent spinal surgery for LDD in 2009. The patients were followed up until 2016. Medical comorbidity was assessed according to the Charlson comorbidity index (CCI). Cox proportional hazard regression modeling was used to identify significant differences in sex, surgery, age, causative disease, and comorbidity. Results : The study cohort included 78241 patients; 10328 patients (13.2%) underwent reoperation during the observation period. The reoperation rate was statistically higher (p<0.01) in males, patients 55-74 years and 65-74 years of age, and patients with decompression or discectomy. Significant association was found between increasing reoperation rate and CCI score (p<0.01). Based on multivariate analysis of comorbidities, the significantly higher reoperation rates were observed in patients with peripheral vascular disease, pulmonary lung disease, peptic ulcer, diabetes, and diabetes complications (p<0.01). Conclusion : The study results indicate the reoperation rate for LDD is associated with patient comorbidities. The comorbidities identified in this study could be helpful in future LDD studies.

• Journal of Preventive Medicine and Public Health
• /
• 제53권5호
• /
• pp.342-352
• /
• 2020

Objectives: The aim of this retrospective cohort study was to investigate whether non-alcoholic fatty liver disease (NAFLD) was associated with incident bone mineral density (BMD) decrease. Methods: This study included 4536 subjects with normal BMD at baseline. NAFLD was defined as the presence of fatty liver on abdominal ultrasonography without significant alcohol consumption or other causes. Decreased BMD was defined as a diagnosis of osteopenia, osteoporosis, or BMD below the expected range for the patient's age based on dual-energy X-ray absorptiometry. Cox proportional hazards models were used to estimate the hazard ratio of incident BMD decrease in subjects with or without NAFLD. Subgroup analyses were conducted according to the relevant factors. Results: Across 13 354 person-years of total follow-up, decreased BMD was observed in 606 subjects, corresponding to an incidence of 45.4 cases per 1000 person-years (median follow-up duration, 2.1 years). In the model adjusted for age and sex, the hazard ratio was 0.65 (95% confidence interval, 0.51 to 0.82), and statistical significance disappeared after adjustment for body mass index (BMI) and cardiometabolic factors. In the subgroup analyses, NAFLD was associated with a lower risk of incident BMD decrease in females even after adjustment for confounders. The direction of the effect of NAFLD on the risk of BMD decrease changed depending on BMI category and body fat percentage, although the impact was statistically insignificant. Conclusions: NAFLD had a significant protective effect on BMD in females. However, the effects may vary depending on BMI category or body fat percentage.

• Safety and Health at Work
• /
• 제2권2호
• /
• pp.135-147
• /
• 2011

Objectives: The purpose of this study was to evaluate cancer risks in the Korean semiconductor industry. Methods: A retrospective cohort study was performed in eight semiconductor factories between 1998 and 2008. The number of subjects was 113,443 for mortality and 108,443 for incidence. Standardized mortality ratios (SMR) and standardized incidence ratios (SIR) were calculated. Results: The SMR of leukemia was 0.39 (95% Confidence Interval 0.08-1.14) in males (2 cases) and 1.37 (0.55-2.81) in females (7 cases). The SMR of non-Hodgkin's lymphoma (NHL) was 1.33 (0.43-3.09, 5 cases) in males and 2.5 (0.68-6.40, 4 cases) in females. The SIR of leukemia was 0.69 (0.30-1.37, 8 cases) in males and 1.28 (0.61-2.36, 10 cases) in females. The SIR of NHL in females was 2.31 (1.23-3.95, 13 cases) and that of thyroid cancer in males was 2.11 (1.49-2.89, 38 cases). The excess incidence of NHL was significant in female assembly operators [SIR=3.15 (1.02-7.36, 5 cases)], but not significant in fabrication workers. The SIR of NHL in the group working for 1-5 years was higher than the SIR of NHL for those working for more than five years. The excess incidence of male thyroid cancer was observed in both office and manufacturing workers. Conclusion: There was no significant increase of leukemia in the Korean semiconductor industry. However, the incidence of NHL in females and thyroid cancer in males were significantly increased even though there was no definite association between work and those diseases in subgroup analysis according to work duration. This result should be interpreted cautiously, because the majority of the cohort was young and the number of cases was small.

• Journal of Preventive Medicine and Public Health
• /
• 제35권4호
• /
• pp.351-358
• /
• 2002

Objective : To evaluate the relationship between physical activity and the risk of hip fracture in the elderly Korean people. Methods : The study population was a Physical Activity Subcohort (n=8,908) extracted from the Korean Elderly Pharmacoepidemiological Cohort (KEPEC). Physical activity information was obtained from a mailed questionnaire surveys. The outcome data was collected from claims data gathered between Jan. 1993 and Dec. 1998. A hospital survey relating to potential cases was conducted to confirm the final diagnoses. The abstracted data was reviewed by a medical doctor before the final diagnoses were confirmed. A mailing questionnaire survey was performed to obtain information on potentially confounding variables, including alcohol intake, smoking habits, weight, height and postmenopausal duration. There were 79 confirmed cases hospitalized due to hip fractures between Jan. 1993 and Dec. 1998. Relative risk of physical activity scores on the hip fracture, and their 95% confidence intervals, were estimated by a Cox's proportional hazard model using SAS for Windows ver.6.12. Results : Compared to the reference group, the adjusted relative risk of hip fracture associated with the most physical active category: after controlling for age, weight and alcohol intake in the males, and for weight, alcohol intake and postmenopausal duration in the females, were 1.04 (95% CI=0.35-3.06) and 0.f4 (95% CI=0.26-0.77), respectively. Conclusions : Physical activity may protect elderly women from hip fracture.

• Journal of Korean Medical Science
• /
• 제33권53호
• /
• pp.341.1-341.11
• /
• 2018

Background: The converging epidemics of tuberculosis (TB) and end-stage renal disease (ESRD) have generated a significant public health burden, however, previous studies have been limited to a small number of patients. This nationwide cohort study aimed to assess the rate of developing active TB among patients receiving dialysis for ESRD. Methods: The Korean national health insurance database was used to identify patients receiving dialysis for new-onset ESRD during 2004-2013, who were propensity score matched to an equivalent number of non-dialysis subjects from the general population. The incidences of active TB in the ESRD and control cohorts were calculated for 2004-2013, and multivariable Cox proportional hazards model was used to evaluate the ESRD-related risk of active TB. Results: During 2004-2013, 59,584 patients received dialysis for newly diagnosed ESRD. In the dialysis and control cohorts, 457 (0.8%) and 125 (0.2%) cases of active TB were detected, respectively. Patients with ESRD were associated with a significantly higher risk of active TB compared to the controls (incidence rate ratio, 4.80). The ESRD cohort had an independently elevated risk of active TB (adjusted hazard ratio, 4.39; 95% confidence interval, 3.60-5.37). Conclusion: We found that patients receiving dialysis for ESRD had an elevated risk of active TB. These results highlight the need for detailed and well-organised guidelines for active TB screening among patients with ESRD.