• Journal of Preventive Medicine and Public Health
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• v.36 no.3
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• pp.213-222
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• 2003

Genomic epidemiology is defined as 'an evoking field of inquiring that uses the systematic application of epidemiologic methods are approaches in population-based studies of the impact of human genetic variation on health and disease (Khoury, 1998)'. Most human diseases are caused by the intricate interaction among environmental exposures and genetic susceptibility factors. Susceptibility genes involved in disease pathogenesis are categorized into two groups: high penetrance genes (i.e., BRAC1, RB, etc.) and lour penetranoe genes (i.e., GSTs, Cyps, XRCC1, ets.), and low penetrance susceptibility genes has the higher priority for epidemiological research due to high population attributable risk. In this paper, the summarized results of the association study between single nucleotide polymorphisms (SNPs) and breast cancer in Korea were introduced and the international trends of genomic epidemiology research were reviewed with an emphasis on internee-based case-control and cohort consortium.

• 대한예방의학회:학술대회논문집
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• 2004.10a
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• pp.81.1-81.1
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• 2004

• Childhood Kidney Diseases
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• v.27 no.2
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• pp.111-116
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• 2023

Purpose: This article was to investigate the association between urinary tract infections (UTIs) and high weight status in infancy. Methods: We conducted a nationwide matched cohort study from January 2018 to December 2020 using data from the Korean National Health Insurance System and the Korean National Health Screening Program for Infants and Children. We analyzed the association between UTI diagnosis codes and high weight status (which was defined as being in the 90th percentile or higher of weight-for-age). Results: We found that 22.8% of infants with UTIs exhibited high weight status, compared to 20.0% of non-UTI infants (P<0.001). Per our multivariable analyses, the adjusted odds ratio for high weight status was 1.09 (95% confidence interval, 1.06-1.13). Conclusions: UTI in the first 12 months of life was associated with a weight-for-age percentile of ≥90. Our findings corroborate those of previous single-center studies and emphasize the importance of careful monitoring for this at-risk group.

• Journal of Preventive Medicine and Public Health
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• v.53 no.6
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• pp.476-486
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• 2020

Objectives: The objective of this study was to estimate the risk of lung cancer in relation to angiotensin II receptor blocker (ARB) use among patients with hypertension from the Korean National Health Insurance Service-National Health Screening Cohort. Methods: We conducted a retrospective cohort study of patients with hypertension who started to take antihypertensive medications and had a treatment period of at least 6 months. We calculated the weighted hazard ratios (HRs) and their 95% confidence intervals (CIs) of lung cancer associated with ARB use compared with calcium channel blocker (CCB) use using inverse probability treatment weighting. Results: Among a total of 60 469 subjects with a median follow-up time of 7.8 years, 476 cases of lung cancer were identified. ARB use had a protective effect on lung cancer compared with CCB use (HR, 0.75; 95% CI, 0.59 to 0.96). Consistent findings were found in analyses considering patients who changed or discontinued their medication (HR, 0.50; 95% CI, 0.32 to 0.77), as well as for women (HR, 0.56; 95% CI, 0.34 to 0.93), patients without chronic obstructive pulmonary disease (HR, 0.75; 95% CI, 0.56 to 1.00), never-smokers (HR, 0.64; 95% CI, 0.42 to 0.99), and non-drinkers (HR, 0.69; 95% CI, 0.49 to 0.97). In analyses with different comparison antihypertensive medications, the overall protective effects of ARBs on lung cancer risk remained consistent. Conclusions: The results of the present study suggest that ARBs could decrease the risk of lung cancer. More evidence is needed to establish the causal effect of ARBs on the incidence of lung cancer.

• Journal of Preventive Medicine and Public Health
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• v.32 no.4
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• pp.513-525
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• 1999

Objectives : High-normal blood pressure' is a factor influencing decision to initiate targeted intensive intervention strategy in westernized populations. JNC-VI offered the vigorous lifestyle modification for persons with 'high-normal blood pressure', who could be early detected. As a hypertension seems to be the result of multiple genetic factors operating in concert with associated environmental factors, it will be necessary to identify the high-normal blood pressure as a risk factor of hypertension for applying primary prevention strategy in Korean people. Methods : Although cohort study design might be adequate to recruit incidence cases, to keep time sequence of events, and to prevent information bias, nested case-control study was chosen for avoiding measurement errors because hypertension is a benign disease. Source population was the 'Seoul Cohort' participants and follow-up was done by using Korea Medical Insurance Corporation's database on the utilization of health services from 1 Jan93 to 30Jun97. Incidence cases were ascertained through the chart review, telephone contacts, and direct blood pressure measurements. Controls included the pairing of 4 individuals to each case on the basis of age. Results : As 75% of 247 incident cases had high-normal blood pressure, the crude odds ratio for hypertension was 2.04 (95% CI 1.47-2.83). Another statistically significant risk factors of hypertension were body mass index, dietary fiber, alcohol consumption, weekly activity and history of quitting smoking. The multivariate odds ratio of high-normal blood pressure adjusted for all risk factors was 1.84 (95% CI 1.31-2.56). Among high-normal blood pressure group, body mass index, weekly ethanol amounts, weekly physical activity, and dietary fiber except history of quitting smoking were still risk factors of hypertension. Conclusion : 'High-normal blood pressure' is a risk factor for hypertension in Korean middle-aged men, which represents that the vigorous lifestyle modification for persons with 'high-normal blood pressure' is need.

• Environmental Analysis Health and Toxicology
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• v.31
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• pp.23.1-23.6
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• 2016

Objectives A stable follow-up participation rate is a very important factor for validity in a cohort study. This study analyzed the factors that affect the participation rate at one hospital-based birth cohort in South Korean. Methods The participants were recruited from the Mothers' and Children's Environmental Health study between 2006 and 2010. The analysis targeted 1751 mothers who participated in a birth cohort. We conducted analyses of general characteristics during pregnancy and those of infants at birth that affect the participation rate of the 6-month follow-up survey. Results The participation rate for the 6-month follow-up survey was 60.4%. The participation rate in the follow-up of the subsequent period decreased within a 5% to 10% range compared to the number of subjects. The participation rate of premature infants was 16.9% lower than that of a full-term infant (52.6% vs. 69.5%). Analysis showed a 16.7% difference between the participation rate of low-birthweight infants in follow-ups (53.7%) and the participation rate of infants with normal weight (70.4%). The participation rate of mothers who were employed during pregnancy was significantly lower for the 6-month follow-up compared to the participation rate of mothers who were unemployed during pregnancy. Conclusions In this study, factors such as premature birth, low-birthweight, and the employment status of the mother during pregnancy affected the participation rate of the follow-up survey for the birth cohort at six months. A specific strategy is needed to encourage survey participation for the high risk groups in the follow-ups.

• Journal of Preventive Medicine and Public Health
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• v.41 no.1
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• pp.23-29
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• 2008

Objectives : We examined the association between alcohol consumption and incidence of colorectal cancer in elderly Koreans. Methods : The cohort members (n=14,304) consisted of 4,834 males and 9,470 females derived from the Korea Elderly Pharmacoepidemiologic Cohort (KEPEC), a population-based dynamic cohort. They were aged 65 years old or older and lived in Busan between 1993-1998; they were beneficiaries of the Korean Medical Insurance Corporation (KMIC). Baseline information was surveyed by a self-administered, mailed questionnaire. This study population was restricted to 14,304 participants who reported alcohol drinking habits on the questionnaire and had not been diagnosed with colorectal cancer at baseline. The adjusted hazard ratios (aHR) of status, type, frequency and daily average amount of alcohol consumption were computed with Cox's proportional hazard model, with the never-drinkers as a reference group and controlling for age and gender. Results : After 4.82 person-years of mean follow-up 112 cases of colorectal cancer occurred. The incidence densities of colorectal cancer were 161 (95% CI=123-200) for never-drinkers, 219 (95% CI=125-339) for ex-drinkers, and 137 (95% CI=84-189) for current-drinkers per 100,000 person-year. The status, type, frequency, and daily average amount of alcohol consumption were not significantly related to the incidence of colorectal cancer after controlling for age and gender. Conclusions : There was no significant association between alcohol consumption and colorectal cancer among elderly people after controlling for age and gender.

• Korean Journal of Community Nutrition
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• v.26 no.3
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• pp.211-227
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• 2021

Objectives: We aimed to examine the association between the relative preference for vegetables and meat and cancer incidence, in a population-based retrospective cohort in Korea. Methods: We included 10,148,131 participants (5,794,124 men; 4,354,007 women) who underwent national health screening between 2004 and 2005 from the National Health Information Database of the National Health Insurance Service (NHIS-NHID). Participants were asked whether they preferred consuming 1) vegetables more often, 2) both vegetables and meat or 3) meat more often. Participants were followed up to Dec. 31, 2017. All cancer and eighteen common cancer cases were identified through the code from the International Classification of Diseases, 10th revision. We estimated sex-specific relative risks and 95% confidence intervals, adjusting for age, body mass index, alcohol consumption, smoking, physical activity, and income level. Results: During an average follow-up of 12.4 years, 714,170 cancer cases were documented. In men, consuming meat more often was associated with lower risk of esophageal, liver, and stomach cancers, but higher risk of lung and kidney cancers. Consuming both vegetables and meat was associated with higher risk of prostate cancer, but with lower risk of esophageal, liver, and stomach cancers in men. In women, consuming meat more often was associated with a higher risk of colorectal cancer and breast, endometrial, and cervical cancers diagnosed before the age of 50. Consuming both vegetables and meat was associated with lower risk of liver cancer in women. Conclusions: Our study suggests a potential link between vegetable and meat intake and cancer incidence in the Korean population. Further investigation on the association between the intake of specific types of vegetables and meat and cancer risk in Korean prospective cohort studies is needed.

• Journal of Chest Surgery
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• v.54 no.2
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• pp.88-98
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• 2021

Background: This study aimed to develop a new risk prediction model for operative mortality in a Korean cohort undergoing heart valve surgery using the Korea Heart Valve Surgery Registry (KHVSR) database. Methods: We analyzed data from 4,742 patients registered in the KHVSR who underwent heart valve surgery at 9 institutions between 2017 and 2018. A risk prediction model was developed for operative mortality, defined as death within 30 days after surgery or during the same hospitalization. A statistical model was generated with a scoring system by multiple logistic regression analyses. The performance of the model was evaluated by its discrimination and calibration abilities. Results: Operative mortality occurred in 142 patients. The final regression models identified 13 risk variables. The risk prediction model showed good discrimination, with a c-statistic of 0.805 and calibration with Hosmer-Lemeshow goodness-of-fit p-value of 0.630. The risk scores ranged from -1 to 15, and were associated with an increase in predicted mortality. The predicted mortality across the risk scores ranged from 0.3% to 80.6%. Conclusion: This risk prediction model using a scoring system specific to heart valve surgery was developed from the KHVSR database. The risk prediction model showed that operative mortality could be predicted well in a Korean cohort.

• Tuberculosis and Respiratory Diseases
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• v.84 no.2
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• pp.115-124
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• 2021

Background: This study aimed to determine the parameters for worsening oxygenation in non-severe coronavirus disease 2019 (COVID-19) pneumonia. Methods: This retrospective cohort study included cases of confirmed COVID-19 pneumonia in a public hospital in South Korea. The worsening oxygenation group was defined as that with SpO₂ ≤94% or received oxygen or mechanical ventilation (MV) throughout the clinical course versus the non-worsening oxygenation group that did not experience any respiratory event. Parameters were compared, and the extent of viral pneumonia from an initial chest computed tomography (CT) was calculated using artificial intelligence (AI) and measured visually by a radiologist. Results: We included 136 patients, with 32 (23.5%) patients in the worsening oxygenation group; of whom, two needed MV and one died. Initial vital signs and duration of symptoms showed no difference between the two groups; however, univariate logistic regression analysis revealed that a variety of parameters on admission were associated with an increased risk of a desaturation event. A subset of patients was studied to eliminate potential bias, that ferritin ≥280 ㎍/L (p=0.029), lactate dehydrogenase ≥240 U/L (p=0.029), pneumonia volume (p=0.021), and extent (p=0.030) by AI, and visual severity scores (p=0.042) were the predictive parameters for worsening oxygenation in a sex-, age-, and comorbid illness-matched case-control study using propensity score (n=52). Conclusion: Our study suggests that initial CT evaluated by AI or visual severity scoring as well as serum markers of inflammation on admission are significantly associated with worsening oxygenation in this COVID-19 pneumonia cohort.