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Abstract: Trifluralin, 2,6-dinitro-N,N-dipropyl-4-trifluoromethylaniline, is a 2,6-dinitro herbicide widely used to control annual grasses and broadleaf weeds in agricultural settings. The association between trifluralin use and common cancer incidence was evaluated among 50,127 private and commercial pesticide applicators in the Agricultural Health Study (AHS), a prospective cohort study of licensed pesticide applicators and their spouses in Iowa and North Carolina. Poisson regression was used to examine internal dose–response relationships, while controlling for important lifestyle factors and other agricultural exposures. Two metrics of exposure (lifetime days and intensity-weighted lifetime days) were used in exposure–response analyses with non-exposed applicators, as well as applicators in the lowest tertile of exposure, as reference groups. Incident cancers were identified through state tumor registries from enrollment in 1993 through 2002. Trifluralin exposure was not associated with cancer incidence overall among 51% of private and commercial applicators (n=25,712) who had used trifluralin. However, there was an excess of colon cancer in the exposure category of higher half of highest tertile (rate ratios (RR) of 1.76 (95% CI=1.05–2.95) using the non-exposed as a referent and 1.93 (95% CI=1.08–3.45) using those with the lowest tertile of exposure as the referent). There was also a non-significantly elevated risk for kidney cancer and bladder cancer in the highest exposure group, although only the kidney cancer finding was consistent across exposure metrics. Although there was a possible link between trifluralin exposure and colon cancer, small numbers and inconsistencies in dose–response and subgroup analyses indicate that this may be a chance finding. [Copyright &y& Elsevier]

Objectives. Public health concern about the health effects of radio-frequency electromagnetic fields (RF-EMFs) has increased with the increase in public exposure. This study was to evaluate some health effect of RF exposure by the AM radio broadcasting towers in Korea. Methods. We calculated cancer mortality rates using Korean death certificates over the period of 1994–1995 and population census data in ten RF-exposed areas, defined as regions that included AM radio broadcasting towers of over 100 kW, and in control areas, defined as regions without a radio broadcasting tower inside and at least 2 km away from the towers. Results. All cancers-mortality was significantly higher in the exposed areas [direct standardized mortality rate ratio (MRR) =1.29, 95%CI=1.12–1.49]. When grouped by each exposed area and by electrical power, MRRs for two sites of 100 kW, one site of 250 kW and one site of 500 kW, for all subjects, and for one site of 100 kW and two sites of 250 kW, for male subjects, showed statistically significant increases without increasing trends according to the groups of electric power. Leukemia mortality was higher in exposed areas (MRR=1.70, 95% CI=0.84–3.45), especially among young adults aged under 30 years (0–14 years age group, MRR=2.29, 95% CI=1.05–5.98; 15–29 age group, MRR=2.44, 95% CI=1.07–5.24) . Conclusions. We observed higher mortality rates for all cancers and leukemia in some age groups in the area near the AM radio broadcasting towers. Although these findings do not prove a causal link between cancer and RF exposure from AM radio broadcasting towers, it does suggest that further analytical studies on this topic are needed in Korea. [ABSTRACT FROM AUTHOR]

To evaluate the potential association between NAT1/NAT2 polymorphisms and breast cancer, a case-control study was conducted in Korean women (254 cases, 301 controls). NAT1 *4/*10 genotype (42%) was the most common NAT1 genotype in this Korean population. The frequencies of slow, intermediate and rapid NAT2 acetylator genotype were 16, 39 and 44% in cases and 16, 42 and 42% in controls. Neither NAT1 rapid (homozygous or heterozygous NAT1 *10) (OR=1.2, 95% CI=0.8–1.9) nor NAT2 rapid acetylator genotype (OR=1.2, 95% CI=0.8–1.7) showed significant association with breast cancer risk. Although the risk of NAT2 rapid acetylator genotype in postmenopausal women (OR=1.4, 95% CI=0.7–2.8) was higher than that in premenopausal women (OR=1.1, 95% CI=0.7–1.7), those were not statistically significant. However, combinations of NAT1, GSTM1 and GSTT1 genotypes showed a significant linear gene-dosage relationship with breast cancer (p for trend=0.04) and those women with NAT2 rapid acetylator and both GSTM1 and GSTT1 null genotypes were at the elevated risk (OR=3.1, 95% CI=1.0–9.1). These results suggest that genetic polymorphisms of NAT1 and NAT2 have no independent effect on breast cancer risk, but they modulate breast cancer risk in the presence of GSTM1 and GSTT1 null genotypes. [Copyright &y& Elsevier]

Background: The 2021 Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline for the management of blood pressure (BP) in chronic kidney disease (CKD) recommends a target systolic BP of <120 mmHg as this target can provide cardiovascular benefits. However, it remains unclear whether implementing the new BP target could improve kidney outcomes. Methods: The association between the 2021 KDIGO BP target and CKD progression was examined and compared with the 2012 KDIGO BP target among 1724 participants included in the KoreaN Cohort Study for Outcomes in Patients With CKD. The main exposure was the BP status categorized according to the 2012 or 2021 KDIGO guideline: (1) controlled within the 2021 target, (2) controlled within the 2012 target only, and (3) above both targets. The primary outcome was a composite kidney outcome of ≥50% decline in the estimated glomerular filtration rate from baseline or the initiation of kidney replacement therapy during the follow‐up period. Results: Composite kidney outcomes occurred in 650 (37.7%) participants during the 8078 person‐years of follow‐up (median, 4.9 years). The incidence rates of this outcome were 55, 66.5, and 116.4 per 1000 person‐years in BP controlled within the 2021 and 2012 KDIGO targets, and BP above both targets, respectively. In the multivariable cause‐specific hazard model, hazard ratios for the composite outcome were 0.76 (95% confidence interval (CI), 0.60–0.95) for BP controlled within the 2021 target and 1.36 (95% CI, 1.13–1.64) for BP above both targets, compared with BP controlled within 2012 target only. Conclusion: The newly lowered BP target by the 2021 KDIGO guideline was associated with improved kidney outcome compared with BP target by the 2012 KDIGO guideline. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate changes in health-related quality of life (HRQOL) in patients with chronic kidney disease (CKD) according to decline in kidney function. HRQOL was assessed using the Short Form-36 questionnaire composed of a physical component summary (PCS) and mental component summary (MCS). Rapid decline in kidney function was defined as a decline in the estimated glomerular filtration rate (eGFR) of > 3 mL/min/1.73 m2/year. Rapid deterioration of HRQOL was defined a change in the HRQOL value greater than the median. Among 970 patients, 360 (37.1%) were in the rapid kidney function decline group. In 720 patients who were 1:1 propensity score-matched, the baseline eGFR was not significantly different between the non-rapid and rapid kidney function decline groups. Compared with the baseline PCS score, the 5-year PCS score decreased in the non-rapid and rapid kidney function decline groups. The 5-year MCS score significantly decreased in the rapid kidney function decline group alone. Rapid decline in kidney function was significantly associated with rapid deterioration of the PCS (odds ratio [OR]: 1.48; 95% confidence interval [CI]: 1.07–2.05; P = 0.018) and MCS (OR: 1.89; 95% CI 1.36–2.62; P < 0.001) scores. Rapid decline in kidney function was associated with rapid deterioration of HRQOL in patients with CKD. [ABSTRACT FROM AUTHOR]

High coronary artery calcification (CAC) burden is a significant risk factor for adverse cardiovascular and kidney outcomes. However, it is unknown whether changes in the coronary atherosclerotic burden can accompany changes in kidney disease progression. Here, we evaluated the relationship between CAC progression and the risk of kidney failure with replacement therapy (KFRT). We analyzed 1173 participants with chronic kidney disease (CKD) G1 to G5 without kidney replacement therapy from the KoreaN Cohort Study for Outcomes in Patients With Chronic Kidney Disease (KNOW-CKD). Participants were categorized into three groups according to the change in the CAC score between enrollment and year 4 (non-progressors, ≤0 AU; moderate progressors, 1–199 AU; and severe progressors, ≥200 AU). The primary outcome was the development of KFRT. During a follow-up period of 4690 person-years (median, 4.2 years), the primary outcome occurred in 230 (19.6 %) participants. The incidence of KFRT was 37.6, 54.3, and 80.9 per 1000 person-years in the non-, moderate, and severe progressors, respectively. In the multivariable cause-specific hazard model, the hazard ratios (HRs) for the moderate and severe progressors were 1.71 (95 % confidence interval [CI], 1.02–2.87) and 2.55 (95 % CI, 1.07–6.06), respectively, compared with non-progressors. A different definition of CAC progression with a threshold of 100 AU yielded similar results in a sensitivity analysis. CAC progression is associated with an increased risk of KFRT in patients with CKD. Our findings suggest that coronary atherosclerosis changes increase the risk of CKD progression. [Display omitted] • Coronary artery calcification (CAC) is common in patients with chronic kidney disease (CKD). • CAC progression was more evident in patients with advanced CKD. • Greater CAC progression was associated with a higher risk for kidney failure with replacement therapy in patients with CKD. • CAC score assessment and follow-up could serve as a valuable tool for risk stratification in patients with CKD. [ABSTRACT FROM AUTHOR]

Proteinuria is typically quantified according to the spot urine protein–creatinine ratio (UPCR) and an association with cardiovascular events has not been thoroughly investigated in chronic kidney disease (CKD) patients. We investigated whether the severity of proteinuria assessed by spot UPCR is associated with an increased risk for cardiovascular outcomes in the CKD population, and whether the relationship is influenced by urine creatinine concentration. We analyzed 1746 patients enrolled as part of The KoreaN cohort study for Outcome in patients With Chronic Kidney Disease (KNOW-CKD). Multivariable Cox proportional hazard analysis was performed to evaluate models with proteinuria as a predictor of renal events and extended major adverse cardiovascular events (eMACEs). Risk for renal events was significantly associated with proteinuria across all eGFR and UPCR categories. By contrast, risk for eMACEs increased significantly with UPCR in patients with eGFR ≥ 60 mL/min/1.73 m2 (hazard ratio [HR] 2.109; 95% confidence interval [CI] 1.375–3.235; P = 0.001), but not in patients with eGFR < 60 mL/min/1.73 m2 (HR 1.086; 95% CI 0.910–1.296; P = 0.358). However, in those with the lower eGFR, risk for eMACEs increased significantly with UPCR in participants with urine creatinine concentration ≥ 95 mg/dL (HR 1.503; 95% CI 1.047–2.159; P = 0.027). In non-dialysis CKD patients, the prognostic value of UPCR for eMACEs is weakened in patients with reduced eGFR levels, for whom it has prognostic significance only in patients with high urine creatinine concentration. [ABSTRACT FROM AUTHOR]

Chronological age (CA) predicts health status but its impact on health varies with anthropometry, socioeconomic status (SES), and lifestyle behaviors. Biological age (BA) is, therefore, considered a more precise predictor of health status. We aimed to develop a BA prediction model from self-assessed risk factors and validate it as an indicator for predicting the risk of chronic disease. A total of 101,980 healthy participants from the Korean Genome and Epidemiology Study were included in this study. BA was computed based on body measurements, SES, lifestyle behaviors, and presence of comorbidities using elastic net regression analysis. The effects of BA on diabetes mellitus (DM), hypertension (HT), combination of DM and HT, and chronic kidney disease were analyzed using Cox proportional hazards regression. A younger BA was associated with a lower risk of DM (HR = 0.63, 95% CI: 0.55–0.72), hypertension (HR = 0.74, 95% CI: 0.68–0.81), and combination of DM and HT (HR = 0.65, 95% CI: 0.47–0.91). The largest risk of disease was seen in those with a BA higher than their CA. A consistent association was also observed within the 5-year follow-up. BA, therefore, is an effective tool for detecting high-risk groups and preventing further risk of chronic diseases through individual and population-level interventions. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: As the population of patients with lung cancer increases, the expenditure on lung cancer treatment will become a huge economic burden in many countries. To support public health services for the treatment of lung cancer, the calculation of lung cancer-specific costs is important. Methods: This study included newly diagnosed 76 lung cancer patients who had survived for at least 5 years after the diagnosis in a tertiary care hospital in South Korea. Direct medical costs were calculated from health care claims obtained from Seoul National University Hospital, which included out-of-pocket expenditures. Direct non-medical and indirect costs were calculated from national statistics. Results: Mean direct medical costs, direct non-medical costs, and indirect costs amounted to $21,321, $6444 and $4943 respectively, based on an exchange rate of Korean Won 1200=US $1. The average cost for treatment of one lung cancer patient for all 5 years was $32,708. This constituted 44.7% of the per capita income during the same 5-year period. Conclusion: The economic burden of lung cancer treatment is significant in Korea. [Copyright &y& Elsevier]

To evaluate the association between genetic polymorphism of GSTM1, GSTT1 and development of bladder cancer, a hospital-based case-control study was conducted in South Korea. The study population consisted of 232 histologically confirmed male bladder cancer cases and 165 male controls enrolled from urology departments with no previous history of cancer or systemic diseases in Seoul during 1997–1999. The GSTM1 null genotype was significantly associated with bladder cancer (OR: 1.6, 95% CI: 1.0–2.4), whereas the association observed for GSTT1 null genotype did not reach statistical significance (OR: 1.3, 95% CI: 0.9–2.0). There was a statistically significant multiple interaction between GSTM1 and GSTT1 genotype for risk of bladder cancer (P=0.04); the risk associated with the concurrent lack of both of the genes (OR: 2.2, 95% CI: 1.2–4.3) was greater than the product of risk in men with GSTM1 null/GSTT1 present (OR: 1.3, 95% CI: 0.7–2.5) or GSTM1 present/GSTT1 null (OR: 1.1, 95% CI: 0.6–2.2) genotype combinations. [Copyright &y& Elsevier]

Proteinuria and hyperphosphatemia are risk factors for cardiovascular disease in patients with chronic kidney disease (CKD). Although the interaction between proteinuria and the serum phosphate level is well established, the mechanistic link between the two, particularly the extent to which this interaction is mediated by phosphate-regulating factors, remains poorly understood. In this study, we examined the association between proteinuria and the serum phosphate level, as well as potential mediators, including circulating fibroblast growth factor (FGF23)/klotho, the 24-h urinary phosphate excretion rate to glomerular filtration rate ratio (EP/GFR), and the 24-h tubular phosphate reabsorption rate to GFR ratio (TRP/GFR). The analyses were performed with data from 1793 patients in whom 24-h urine protein and phosphate, serum phosphate, FGF23, and klotho levels were measured simultaneously, obtained from the KoreaN cohort study for Outcome in patients With Chronic Kidney Disease (KNOW-CKD). Multivariable linear regression and mediation analyses were performed. Total, direct, and indirect effects were also estimated. Patients with high serum phosphate levels were found to be more likely to exhibit greater proteinuria, higher FGF23 levels, and lower klotho levels. The 24-h EP/GFR increased and the 24-h TRP/GFR decreased with increasing proteinuria and CKD progression. Simple mediation analyses showed that 15.4% and 67.9% of the relationship between proteinuria and the serum phosphate level were mediated by the FGF23/klotho ratio and 24-h EP/GFR, respectively. Together, these two factors accounted for 73.1% of the relationship between serum markers. These findings suggest that proteinuria increases the 24-h EP/GFR via the FGF23/klotho axis as a compensatory mechanism for the increased phosphate burden well before the reduction in renal function is first seen. [ABSTRACT FROM AUTHOR]

Purpose: Obesity is linked to poor health-related quality of life (HRQOL) in the general population, but its role in chronic kidney disease (CKD) is uncertain.Methods: We conducted a cross-sectional study that investigated 1880 participants from the KoreaN cohort study for Outcome in patients With CKD (KNOW-CKD) who underwent complete baseline laboratory tests, health questionnaires, and HRQOL. HRQOL was assessed by physical component summary (PCS) and mental component summary (MCS) of the SF-36 questionnaire. We used multivariable linear regression models to examine the relationship between Body Mass Index (BMI) and sex-specific waist circumference (WC) with HRQOL.Results: Adults with higher BMI and greater WC showed lower PCS. After adjusting for age, sex, socioeconomic state, comorbidities, and laboratory findings, we found that WC, but not BMI, was associated with PCS. Greater WC quintiles were associated with lower PCS [WC-4th quintile (β, - 2.63, 95% CI - 5.19 to - 0.06) and WC-5th quintile (β, - 3.71, 95% CI - 6.28 to - 1.15)]. The association between WC and PCS was more pronounced in older adults, woman, patients with diabetes, cardiovascular disease, or lower eGFR. The relationship between BMI and WC with MCS was not significant.Conclusions: In adults with CKD, WC is a better indicator of poor physical HRQOL than BMI. The association between WC and physical HRQOL is modified by age, sex, eGFR, and comorbidities such as diabetes and cardiovascular disease. [ABSTRACT FROM AUTHOR]

Background: Anemia is a common complication among patients with chronic kidney disease (CKD), and it is associated with unfavorable clinical outcomes in patients with CKD independent of the estimated glomerular filtration rate (eGFR). We assessed the association of the urinary albumin-to-creatinine ratio (ACR) and eGFR with anemia in CKD patients. Methods: We conducted a cross-sectional study using baseline data from the KoreaN Cohort Study for Outcome in Patients With Chronic Kidney Disease (KNOW-CKD). Multiple regression analysis was performed to identify the independent association of albuminuria with anemia. Furthermore, odds ratios for anemia were calculated by cross-categorization of ACR and eGFR. Results: Among 1,456 patients, the mean age was 53.5 ± 12.4 years, and the mean eGFR and ACR were 51.9 ± 30.5 mL/min per 1.73 m2 and 853.2 ± 1,330.3 mg/g, respectively. Anemia was present in 644 patients (40.5%). Multivariate analysis showed that the odds ratio of anemia increased according to ACR levels, after adjusting for age, sex, eGFR, body mass index, pulse pressure, cause of CKD, use of erythropoiesis stimulating agents, serum calcium and ferritin (ACR < 30 mg/g as a reference group; 30–299 mg/g, adjusted odds ratio (OR) = 1.43, 95% confidence interval (CI) = 0.88–2.33; ≥300 mg/g, adjusted OR = 1.86, 95% CI = 1.12–3.10). In addition, graded associations were observed in cross-categorized groups of a higher ACR and eGFR compared to the reference group with an ACR <30 mg/g and eGFR ≥60 mL/min per 1.73 m2. Conclusion: The present study demonstrated that albuminuria was a significant risk factor for anemia in CKD patients independent of the eGFR. [ABSTRACT FROM AUTHOR]

Background: Spontaneous abortion (SA) affects 11.2% of recognized pregnancies in Korea. Many studies have focused on the increased risk of SA in obese populations, but there are few studies that have focused on underweight (Body mass index (BMI) <18.5 kg/m2) women, especially in relation to pre-pregnancy BMI. The aim of this study was to examine the role of pre-pregnancy BMI at age 18-20 in later SA.Methods: Among the women who were ever pregnant in the Health Examinees Study (HEXA), which was one of the cohorts studied in the KoGES (Korean Genome and Epidemiology Study) from 2004 to 2012 (N = 80,447), the likelihood of SA based on pre-pregnancy BMI, classified by the criteria for Asians (Underweight: <18.5 kg/m2; Normal range: 18.5-22.9 kg/m2; Overweight at risk: 23-24.9 kg/m2; Obese I: 25-29.9 kg/m2; Obese II: ≥30 kg/m2), was presented as odds ratios (ORs) and 95% confidence intervals (95% CIs) using logistic regression models.Results: Being underweight or obese relative to the normal weight range was associated with a higher likelihood of SA (OR = 1.10 [95% CI = 1.05-1.15] in underweight women and OR = 1.06 [95% CI = 0.96-1.16] in obese women), and this effect was much greater in women who experienced recurrent SAs (for three or more SAs: OR = 1.29 [95% CI 1.14-1.46] in underweight women and OR = 1.39 [95% CI 1.09-1.78] in obese women). Obesity was associated with an increased likelihood of SA at a younger age (≤25 years), whereas underweight was associated with an increased OR of SA at an older age (≥26 years).Discussion: As this study was conducted with baseline data of original cohort which focused on other chronic diseases, recall for previous pregnancy-related information might be less accurate. However, this study shows strength in its large size and prospective potential.Conclusions: Pre-pregnancy BMI at ages 18-20 years revealed a U-shaped association with SA, and underweight and obese women showed increased likelihood for SA during different age periods. [ABSTRACT FROM AUTHOR]

Purpose Kappa is a widely used measure of agreement. However, it may not be straightforward in some situation such as sample size calculation due to the kappa paradox: high agreement but low kappa. Hence, it seems reasonable in sample size calculation that the level of agreement under a certain marginal prevalence is considered in terms of a simple proportion of agreement rather than a kappa value. Therefore, sample size formulae and nomograms using a simple proportion of agreement rather than a kappa under certain marginal prevalences are proposed. Methods A sample size formula was derived using the kappa statistic under the common correlation model and goodness-of-fit statistic. The nomogram for the sample size formula was developed using SAS 9.3. Results The sample size formulae using a simple proportion of agreement instead of a kappa statistic and nomograms to eliminate the inconvenience of using a mathematical formula were produced. Conclusions A nomogram for sample size calculation with a simple proportion of agreement should be useful in the planning stages when the focus of interest is on testing the hypothesis of interobserver agreement involving two raters and nominal outcome measures. [ABSTRACT FROM AUTHOR]

Background: Changes in lifestyle including obesity epidemic and reduced physical activity influenced greatly to increase the cancer burden in Korea. The purpose of the current study was to perform a systematic assessment of cancers attributable to obesity and physical inactivity in Korea. Methodology/Principal Findings: Gender- and cancer site-specific population-attributable fractions (PAF) were estimated using the prevalence of overweight and obesity in 1992–1995 from a large-scale prospective cohort study, the prevalence of low physical activity in 1989 from a Korean National Health Examination Survey, and pooled relative risk estimates from Korean epidemiological studies. The overall PAF was then estimated using 2009 national cancer incidence data from the Korea Central Cancer Registry. Excess body weight was responsible for 1,444 (1.5%) and 2,004 (2.2%) cancer cases among men and women, respectively, in 2009 in Korea. Among men, 6.8% of colorectal, 2.9% of pancreatic, and 16.0% of kidney cancer was attributable to excess body weight. In women, 6.6% of colorectal, 3.9% of pancreatic, 18.7% of kidney, 8.2% of postmenopausal breast, and 32.7% of endometrial cancer was attributable to excess body weight. Low leisure-time physical activity accounted for 8.8% of breast cancer, whereas the PAF for overall cancer was low (0.1% in men, 1.4% in women). Projections suggest that cancers attributable to obesity will increase by 40% in men and 16% in women by 2020. Conclusions/Significance: With a significantly increasing overweight and physically inactive population, and increasing incidence of breast and colorectal cancers, Korea faces a large cancer burden attributable to these risk factors. Had the obese population of Korea remained stable, a large portion of obesity-related cancers could have been avoided. Efficient cancer prevention programs that aim to reduce obesity- and physical inactivity-related health problems are essential in Korea. [ABSTRACT FROM AUTHOR]

Aims: Oxidative stress generated either by exogenous or endogenous sources can lead to progressive organ damage and skin ageing over a long period of time. Moreover, some dermatological signs are independent of chronological ageing, and may reflect the long-term redox state of internal organs. Therefore, we hypothesized that there might be an association between facial wrinkles and decreased renal function, an oxidative stress-related disease. Methods: A cross-sectional study was carried out in a Korean population of 264 adults aged 30 years and older. Facial wrinkle scores in the crow's-foot area were estimated using a standardized form of visual assessment. As an index of renal function, we determined estimated glomerular filtration rate (eGFR). Lipid hydroperoxide (LPO) assay was performed to measure the levels of oxidative stress. Results: After adjusting for possible confounders, lower eGFRs and higher LPO levels were found in those with severe facial wrinkles. Conclusion: We conclude that severe facial wrinkles might be used as a predictive marker of decreased renal function, independently of age, gender and other established risk factors. [ABSTRACT FROM AUTHOR]

Abstract: Background: Hypoxia inducible factor 1 α (HIF-1A) is activated by low oxygen condition tension, a key regulator of the gene involved in the cellular response to hypoxia. Tumors exhibiting extensive hypoxia are more aggressive than tumors oxygenized better. Methods: To evaluate the potential role of the polymorphisms of HIF-1A in the etiology of breast cancer, histologically confirmed incident breast cancer cases (n =1599) and control subjects (n =1536) were recruited. Results: Two selected SNPs (Ex15 + 197C > T and P582S) were not associated with overall breast cancer risk (TT vs. CC: OR=0.9, 95% CI=0.6–1.5, Ser/Ser vs. Pro/Pro: OR=5.5, 95% CI=0.7–45.4, respectively). However, when stratified analyses were performed, significant associations were observed between Ser/Ser genotype at codon 582 and breast cancer risk among women with larger tumor size (> 2 cm) (OR=10.1, 95% CI=1.1–91.1) or without lymph node involvement (OR=9.3, 95% CI=1.1–79.4), although confidence intervals were wide. Conclusions: Our findings support the hypothesis that the HIF-1Α P582S variant may confer susceptibility to subgroups of breast cancer in Korean women. However, further study is warranted due to low statistical power caused by very low minor allele frequencies. [Copyright &y& Elsevier]

Abstract: Objectives: We conducted this study to examine premenopausal risk factors associated with premature ovarian failure (POF) and early menopause (EM) among Korean women. Methods: A 73% of total women aged 30–69 at four districts in the KMCC (Korean Multi-center Cancer Cohort) was participated in this study during 2002–2003. We selected 137 POF and 281 EM cases who had menopause before age 40 and at age 40–44, respectively, and 1318 normal menopause (NM) controls that experienced menopause at age 45–60, and among them, selected idiopathic POF (n =84) and EM (n =261) after excluding surgical/medical menopause. We collected the information of premenopausal lifestyle and reproductive risk factors. Multivariate and polytomous logistic regression were used to estimate POF and EM risk and to differentiate POF and EM risk using ordinal and nominal scale. Results: Cigarette smoking was associated with an increased risk of idiopathic POF (OR=1.82 [1.03–3.23]), whereas oral contraceptive use was associated with a reduced risk of natural EM (OR=0.62 [0.43–0.90]). Idiopathic POF risk by both factors differed from idiopathic EM risk (p-nominal<0.05). Factors related to ovulation, such as later menarche, irregular menstruation and longer breast feeding cumulatively reduced the risk of natural EM and POF (p-ordinal<0.05). In analysis including medical and surgical menopause, lung tuberculosis, hysterectomy, past cancers, and lower number of deliveries before menopause were associated with POF. Conclusions: Our findings indicate that etiology in POF development may partly differ from that in EM. [Copyright &y& Elsevier]

The estrogen receptor-alpha (ERα) has been known to play a role in the development and progression of breast cancer. Several genetic polymorphisms in the ERα gene have been related to breast cancer risk and/or different tumor characteristics. In this study, PCR and direct sequencing based methods were used to examine this issue further in a Korean study population consisting of 155 women, 110 with breast cancer and 45 without cancer. We also assessed the potential role of the ERα genotype in ER, PR, p53, c-erbB2, and bcl-2 expression. Only one of the allelic variants of ERα gene was found in our study subjects; the (C975G) change was present in half of the study subjects. Although this allele had no direct effect in individual breast cancer risk, it was positively associated with tumor PR (P for trend=0.04) and ER expression (P for trend=0.06) and negatively associated with p53 expression (P for trend=0.02). [Copyright &y& Elsevier]

Objectives. To study the epidemiologic details of urolithiasis in Seoul, Korea. The prevalence of urolithiasis varies by different regions in the world and has been reported to be 4% to 15%.Methods. A total of 2643 persons 40 to 79 years old living in Seoul were selected by stepwise random sampling. Questionnaires were used and completed by trained interviewers concerning whether the subjects had experienced urinary stone disease at any time in their life.Results. Of 2643 persons interviewed, 65 experienced 78 episodes of urinary stone formation in their lifetime. Calibrated after the Seoul population census, the overall standardized lifetime prevalence rate was estimated to be 3.5%, 6.0% in men and 1.8% in women. The point prevalence rate was estimated to be 0.9%, 1.9% in men and 0.3% in women. Most of the urinary stone diseases were diagnosed at the fifth decade. Kidney stones in family members were present in 8.1% of patients with stones and 4.1% of stone-free control individuals. Twenty percent of the patients with stones experienced recurrences.Conclusions. In this first systematically assessed epidemiologic survey about the rate of urolithiasis in Korea, 6.0% of Korean men and 1.8% of women are expected to experience urinary stone disease during their lifetime. [Copyright &y& Elsevier]

Apparent treatment-resistant hypertension (ATRH) is closely related to chronic kidney disease (CKD); however, the long-term outcomes and the effects of improvement in ATRH in patients with CKD are not well understood. We evaluated the relationship between the persistence of ATRH and the progression of CKD. This cohort study enrolled 1921 patients with CKD. ATRH was defined as blood pressure above 140/90 mmHg and intake of three different types of antihypertensive agents, including diuretics, or intake of four or more different types of antihypertensive agents, regardless of blood pressure. We defined ATRH subgroups according to the ATRH status at the index year and two years later. The prevalence of ATRH at baseline was 14.0%. The presence of ATRH at both time points was an independent risk factor for end-point renal outcome (HR, 1.41; 95% CI, 1.04–1.92; p = 0.027). On the other hand, the presence of ATRH at any one of the time points was not statistically significant. In conclusion, persistent ATRH is more important for the prognosis of renal disease than the initial ATRH status. Continuous follow-up and appropriate treatment are important to improve the renal outcomes. [ABSTRACT FROM AUTHOR]

Background: Smoking is by far the most important cause of cancer that can be modified at the individual level. Cancer incidence and mortality rates in Korea are the highest among all Asian countries, and smoking prevalence in Korean men is one of the highest in developed countries. The purpose of the current study was to perform a systematic review and provide an evidence-based assessment of the burden of tobacco smoking-related cancers in the Korean population.Methods: Sex- and cancer-specific population-attributable fractions (PAF) were estimated using the prevalence of ever-smoking and second-hand smoking in 1989 among Korean adults, respectively, and the relative risks were estimated from the meta-analysis of studies performed in the Korean population for ever-smoking and in the Asian population for passive smoking. National cancer incidence data from the Korea Central Cancer Registry and national cancer mortality data from Statistics Korea for the year 2009 were used to estimate the cancer cases and deaths attributable to tobacco smoking.Results: Tobacco smoking was responsible for 20,239 (20.9%) cancer incident cases and 14,377 (32.9%) cancer deaths among adult men and 1,930 (2.1%) cancer incident cases and 1,351 (5.2%) cancer deaths among adult women in 2009 in Korea. In men, 71% of lung cancer deaths, 55%-72% of upper aerodigestive tract (oral cavity, pharynx, esophagus and larynx) cancer deaths, 23% of liver, 32% of stomach, 27% of pancreas, 7% of kidney and 45% of bladder cancer deaths were attributable to tobacco smoking. In women the proportion of ever-smoking-attributable lung cancer was 8.1%, while that attributable to second-hand smoking among non-smoking women was 20.5%.Conclusions: Approximately one in three cancer deaths would be potentially preventable through appropriate control of tobacco smoking in Korean men at the population level and individual level. For Korean women, more lung cancer cases and deaths were attributable to second-hand than ever-smoking. Effective control programs against tobacco smoking should be further developed and implemented in Korea to reduce the smoking-related cancer burden. [ABSTRACT FROM AUTHOR]

Background: In the Republic of Korea, cancer is the most common cause of death, and cancer incidence and mortality rates are the highest in East Asia. As alcoholic beverages are carcinogenic to humans, we estimated the burden of cancer related to alcohol consumption in the Korean population.Methods: The cancer sites studied were those for which there is convincing evidence of a positive association with alcohol consumption: oral cavity, pharynx, esophagus, colon, rectum, liver, larynx and female breast. Sex- and cancer-specific population attributable fractions (PAF) were calculated based on: 1) the prevalence of alcohol drinkers among adults ≥ 20 years of age in 1989; 2) the average daily alcohol consumption (g/day) among drinkers in 1998; 3) relative risk (RR) estimates for the association between alcohol consumption and site-specific cancer incidence obtained either from a large Korean cohort study or, when more than one Korean study was available for a specific cancer site, meta-analyses were performed and the resulting meta-RRs were used; 4) national cancer incidence and mortality data from 2009.Results: Among men, 3% (2,866 cases) of incident cancer cases and 2.8% (1,234 deaths) of cancer deaths were attributable to alcohol consumption. Among women, 0.5% (464 cancer cases) of incident cancers and 0.1% (32 deaths) of cancer deaths were attributable to alcohol consumption. In particular, the PAF for alcohol consumption in relation to oral cavity cancer incidence among Korean men was 29.3%, and the PAFs for pharyngeal and laryngeal cancer incidence were 43.3% and 25.8%, respectively. Among Korean women, the PAF for colorectal cancer incidence was the highest (4.2%) and that for breast cancer incidence was only 0.2%. Avoiding alcohol consumption, or reducing it from the median of the highest 4th quartile of consumption (56.0 g/day for men, 28.0 g/day for women) to the median of the lowest quartile (2.80 g/day for men, 0.80 g/day for women), would reduce the burden of alcohol-related cancers in Korea.Conclusions: A reduction in alcohol consumption would decrease the cancer burden and a significant impact is anticipated specifically for the cancers oral cavity, pharynx, and larynx among men in the Republic of Korea. [ABSTRACT FROM AUTHOR]