Duk-Hee Lee

Uppsala University, Uppsala, Uppsala, Sweden

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Publications (79)385.48 Total impact

  • Article: Association of Homocysteine Levels With Blood Lead Levels and Micronutrients in the US General Population.
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    ABSTRACT: Even though several epidemiological studies have observed positive associations between blood lead levels and homocysteine, no study has examined whether this association differs by the levels of micronutrients, such as folate, vitamin B6, and vitamin B12, which are involved in the metabolism of homocysteine. In this study, we examined the interactions between micronutrients and blood lead on homocysteine levels. This study was performed with 4089 adults aged ≥20 years old in the US general population using the National Health and Nutrition Examination Survey 2003-2004. There were significant or marginally significant interactions between micronutrients and blood lead levels on mean homocysteine levels. Positive associations between blood lead and homocysteine were clearly observed among subjects with low levels of folate or low vitamin B6 (p-trend <0.01, respectively). However, in the case of vitamin B12, there was a stronger positive association between blood lead and homocysteine among subjects with high levels of vitamin B12, compared to those with low levels of vitamin B12. In fact, the levels of homocysteine were already high among subjects low in vitamin B12, irrespective of blood lead levels. When we used hyperhomocysteinemia (homocysteine>15 µmol/L) as the outcome, there were similar patterns of interaction, though p-values for each interaction failed to reach statistical significance. In the current study, the association between blood lead and homocysteine differed based on the levels of folate, vitamin B6, or vitamin B12 present in the blood. It may be important to keep sufficient levels of these micronutrients to prevent the possible harmful effects of lead exposure on homocysteine levels.
    Journal of preventive medicine and public health = Yebang Ŭihakhoe chi. 11/2012; 45(6):387-93.
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    Article: Circulating levels of persistent organic pollutants are related to retrospective assessment of life-time weight change.
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    ABSTRACT: Background: Persistent organic pollutants (POPs) have been suggested to be linked to obesity. We have previously shown that less-chlorinated PCBs were positively related to fat mass, while highly-chlorinated PCBs were inversely related to obesity. Objective: The aim of the present evaluation is to investigate the relationship between retrospective assessed life-time change in body weight (20-70years) with circulating POP levels measured at age 70years. Methods: 1016 subjects aged 70years were investigated in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUSs) study. 16 PCBs and 3 OC pesticides were analyzed using HRGC/HRMS. Current body weight was measured and participants self-reported their weight at age 20. Results: The average estimated weight change over 50years was 14.4kg. Both the sum of OC pesticide concentrations (4.3kg more weight gain in quintile 5 vs. quintile 1, p<0.0001) and the sum of the less-chlorinated PCBs were positively related to the estimated weight change (3.7kg more weight gain in quintile 2 vs. quintile 1, non-linear relationship p=0.0015). In contrast, the sum of concentrations of highly-chlorinated PCBs were inversely related to estimated weight change (8.4kg less weight gain in quintile 5 vs. quintile 1, p<0.0001). Conclusion: High levels of OC pesticides and the less-chlorinated PCBs at age 70 were associated with a pronounced estimated weight change over the previous 50years. However, the opposite was seen for highly-chlorinated PCBs. Differences in mode of action, toxicokinetics, non-linear relationships and reverse causation might explain these discrepancies.
    Chemosphere 08/2012; · 3.21 Impact Factor
  • Article: Background exposure to persistent organic pollutants predicts stroke in the elderly.
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    ABSTRACT: Background exposure to persistent organic pollutants (POPs), lipophilic xenobiotics that accumulate mainly in adipose tissue, has recently emerged as a new risk factor for cardiovascular diseases. This prospective study was performed to evaluate if plasma concentrations of selected POPs predict incident stroke among the elderly. Twenty-one POPs (including 16 polychlorinated biphenyl (PCB) congeners, 3 organochlorine (OC) pesticides, 1 brominated diphenyl ether (BDE), and 1 dioxin) were measured in plasma collected at baseline in 898 participants aged 70 years of the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS). Stroke diagnosis was validated by hospital records. During the five year follow-up, 35 subjects developed hospital-treated stroke. After adjusting for known stroke risk factors, most PCBs with 4, 5, or 6 chlorine atoms, p,p'-DDE, trans-nonachlor, and octachlorodibenzo-p-dioxin significantly predicted the risk of stroke. Across quartiles of summary measures of PCBs and OC pesticides, the adjusted ORs were 1.0, 0.8 (95% confidence interval: 0.2-2.5), 1.2 (0.4-3.4), and 2.1 (0.7-6.2) for PCBs and 1.0, 1.2 (0.3-4.2), 2.3 (0.7-6.9), and 3.0 (1.0-9.4) for OC pesticides (P for trend=0.11 and 0.03, respectively). The adjusted ORs among participants ≥ 90th percentile of the summary measures were 5.5 (1.7-18.1) for PCBs and 4.0 (1.1-14.6) for OC pesticides; corresponding ORs for those ≥ 95th percentile were 7.8 (2.1-29.6) and 9.5 (2.3-38.9). Background exposure to POPs may play an important role in development or progression of stroke in the elderly.
    Environment international 07/2012; 47:115-20. · 4.79 Impact Factor
  • Article: Factors Associated with the Use of Gastric Cancer Screening Services in Korea: The Fourth Korea National Health and Nutrition Examination Survey 2008 (KNHANES IV).
    Ji-Yeon Shin, Duk-Hee Lee
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    ABSTRACT: Objectives: Despite government efforts to increase participation in gastric cancer screening, the rate is still suboptimal in Korea. Therefore, we explored barriers to and predictors of gastric cancer screening participation among a nationally representative sample. Methods: We used the Health Interview Survey sub-dataset derived from the Fourth Korean National Health and Nutrition Examination Survey 2008 (KNHANES IV) to evaluate participation in gastric cancer screening and factors associated with attendance in individuals age ≥40 years. We enrolled 4,464 subjects who completed the questionnaire and were not previously diagnosed with gastric cancer. Four groups of factors were considered potential predictors of gastric cancer screening in a multivariate analysis: sociodemographic, health behavior, psychological and cognitive, and dietary factors. Results: Overall, 41.3% complied with the gastric cancer screening recommendations. Younger age, lower education level, living without a spouse, frequent binge drinker, and current smoker were significantly associated with less participation in gastric cancer screening. Conclusions: To improve participation in gastric cancer screening, more focused interventions should be directed to vulnerable populations, such as groups with low socioeconomic status or unhealthy behavior. In addition, there should be new promotional campaigns and health education to provide information targeting these vulnerable populations.
    Asian Pacific journal of cancer prevention: APJCP 01/2012; 13(8):3773-9. · 0.66 Impact Factor
  • Article: Associations between organochlorine pesticides and vitamin D deficiency in the U.S. population.
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    ABSTRACT: Recently low dose organochlorine (OC) pesticides have been strongly linked to various chronic diseases including diabetes and cardiovascular diseases. Both field and animal studies have suggested a possibility that persistent lipophilic chemicals like OC pesticides can cause vitamin D deficiency, but there have been no human studies of exposure to any chemical as a possible cause of vitamin D deficiency. This study was performed to examine if serum concentrations of OC pesticides were associated with serum concentrations of 25-hydroxyvitamin D (25(OH)D) in the U.S. general population. Cross-sectional associations of serum OC pesticides with serum 25(OH)D were investigated in 1,275 subjects aged ≥20 in the National Health and Nutrition Examination Survey (NHANES), 2003-2004. We selected 7 OC pesticides detectable in ≥80% of participants. Among the 7 OC pesticides, p,p'-DDT (β = -0.022, P<0.01), p,p'-DDE (β = -0.018, P = 0.04), and β-hexachlorocyclohexane (β = -0.022, P = 0.02) showed significant inverse associations with serum 25(OH)D levels. When study subjects were stratified by age, race, and the presence of various chronic diseases, p,p'-DDT showed consistent inverse associations in all subgroups, although stronger associations tended to be observed among subjects with old age, white race, or chronic diseases. The current study suggests that the background exposure to some OC pesticides leads to vitamin D deficiency in human. Considering the importance of vitamin D deficiency in the development of chronic diseases, chemical exposure as a possible cause of vitamin D deficiency should be evaluated in prospective and experimental studies.
    PLoS ONE 01/2012; 7(1):e30093. · 4.09 Impact Factor
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    Article: Low serum glutathione peroxidase activity is associated with increased cardiovascular mortality in individuals with low HDLc's.
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    ABSTRACT: Since oxidized LDL is thought to initiate atherosclerosis and the serum glutathione peroxidase (GPx3) reduces oxidized lipids, we investigated whether high GPx3 activity reduces cardiovascular disease (CVD) mortality. We determined GPx3 in stored samples from the Minnesota Heart Survey of 130 participants who after 5 to 12 years of follow-up had died of CVD and 240 controls. Participants were 26 to 85 years old and predominantly white. In a nested case-control, study we performed logistic regressions to calculate odds ratios (OR) adjusted for age, sex, baseline year, body mass index, smoking, alcohol intake, physical activity, total and HDL cholesterols, systolic blood pressure, serum glucose and gamma glutamyltransferase (GTT) activity. The referent was the quartile with the highest GPx3 activity (quartile 4). OR's for CVD mortality for increasing quartiles of GPx3 were 2.37, 2.14, 1.83 and 1.00 (P for trend 0.02). This inverse correlation was confined to those with HDLc's below the median (P for interaction, 0.006). The OR's for increasing quartiles of GPx3 in this group were 6.08, 5.00, 3.64 and 1.00 (P for trend, 0.002). Individuals with both low HDLc and GPx3 activity are at markedly increased risk for death from CVD.
    PLoS ONE 01/2012; 7(6):e38901. · 4.09 Impact Factor
  • Article: Occurrence and accumulation patterns of polycyclic aromatic hydrocarbons and synthetic musk compounds in adipose tissues of Korean females.
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    ABSTRACT: Very few studies have reported on the occurrence and accumulation profiles of polycyclic aromatic hydrocarbons (PAHs) and synthetic musk compounds (SMCs) in human adipose tissue. In this study, concentrations of PAHs and SMCs in adipose tissues collected from Korean women in 2007 and 2008 were determined. Total concentrations of PAHs and SMCs in adipose tissues ranged from 15 to 361 (mean: 119) ngg(-1) lipid weight and from 38 to 253 (mean: 106) ngg(-1) lipid weight, respectively. Concentrations of SMCs in Korean adipose tissues were lower than those reported for European countries and the United States. Naphthalene was the most predominant PAH and HHCB was the dominant SMC found in adipose tissues. The concentrations of PAHs and SMCs were not correlated with each other, suggesting that the sources of human exposure to these two classes of compounds are different. No correlation was found between donor's age and residue levels of PAHs and SMCs. The results of this study provide baseline information on exposure of PAHs and SMCs to the general population in Korea.
    Chemosphere 11/2011; 86(5):485-90. · 3.21 Impact Factor
  • Article: Associations of persistent organic pollutants with abdominal obesity in the elderly: The Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study.
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    ABSTRACT: In animal experiments, persistent organic pollutants (POPs) have induced visceral obesity. To address this possibility in humans, we evaluated associations between POPs and abdominal obesity both cross-sectionally and prospectively. Twenty-one plasma POPs (16 polychlorinated biphenyl (PCB) congeners, 3 organochlorine (OC) pesticides, 1 brominated diphenyl ether (BDE), and 1 dioxin) were measured at baseline in 970 participants aged 70 years of the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS), with prospective analyses in 511 participants re-examined after 5 years. Abdominal obesity was defined by an increased waist circumference. In the cross-sectional analyses, concentrations of the less chlorinated PCBs, OC pesticides such as p,p'-DDE and dioxin had adjusted odds ratios of 2 to 3 for abdominal obesity. Many relations had inverted U-shapes rather than being linear, particularly in women. In contrast, concentrations of highly chlorinated PCBs were strongly inversely associated with abdominal obesity. In a single model including summary measures of the less chlorinated PCBs, highly chlorinated PCBs, and OC pesticides, both the positive associations and inverse associations strengthened. Similar but somewhat weaker associations were seen between POPs and risk of development of abdominal obesity in the prospective analyses. Using both a cross-sectional and a prospective design, low-dose exposure to less chlorinated PCBs, p,p'-DDE, and dioxin, were associated with existence or development of abdominal obesity, while highly chlorinated PCBs had an opposite association in an elderly population, despite the previous observation of higher incident diabetes associated with these same PCBs.
    Environment international 08/2011; 40:170-8. · 4.79 Impact Factor
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    Article: Polychlorinated biphenyls and organochlorine pesticides in plasma predict development of type 2 diabetes in the elderly: the prospective investigation of the vasculature in Uppsala Seniors (PIVUS) study.
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    ABSTRACT: Persistent organic pollutants (POPs), lipophilic chemicals that accumulate mainly in adipose tissue, have recently been linked to type 2 diabetes. However, evidence from prospective studies is sparse. This study was performed to evaluate prospective associations of type 2 diabetes with selected POPs among the elderly. Nineteen POPs (14 polychlorinated biphenyl [PCB] congeners, 3 organochlorine pesticides, 1 brominated diphenyl ether, and 1 dioxin) were measured in plasma collected at baseline in 725 participants, aged 70 years, of the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS). After adjusting for known type 2 diabetes risk factors, including obesity, odds ratios (ORs) (95% CIs) for type 2 diabetes at age 75 years (n = 36) according to the quintiles of a summary measure of concentrations of PCBs (vs. the lowest quintile) were 4.5, 5.1, 8.8 (1.8-42.7), and 7.5 (1.4-38.8) (P(trend) <0.01). Among organochlorine pesticides, adjusted ORs across concentrations of trans-nonachlor showed that P(trend) = 0.03. Adjusted ORs (95% CIs) across quintiles of the sum of three organochlorine pesticides were 1.1, 1.6, 1.5, and 3.4 (1.0-11.7) (P(trend) = 0.03). Neither brominated diphenyl ether 47 nor dioxin was significantly associated with incident diabetes. The sum of PCBs improved reclassification significantly when added to traditional risk factors for diabetes. Despite the small number of incident cases, this study found that environmental exposure to some POPs substantially increased risk of future type 2 diabetes in an elderly population.
    Diabetes care 06/2011; 34(8):1778-84. · 8.09 Impact Factor
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    Article: Polychlorinated Biphenyls and Organochlorine Pesticides in Plasma Predict Development of Type 2 Diabetes in the Elderly
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    ABSTRACT: OBJECTIVE—Persistent organic pollutants (POPs), lipophilic chemicals that accumulate mainly in adipose tissue, have recently been linked to type 2 diabetes. However, evidence from prospective studies is sparse. This study was performed to evaluate prospective associations of type 2 diabetes with selected POPs among the elderly. RESEARCH DESIGN AND METHODS—Nineteen POPs (14 polychlorinated biphenyl [PCB] congeners, 3 organochlorine pesticides, 1 brominated diphenyl ether, and 1 dioxin) were measured in plasma collected at baseline in 725 participants, aged 70 years, of the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS). RESULTS—After adjusting for known type 2 diabetes risk factors, including obesity, odds ratios (ORs) (95% CIs) for type 2 diabetes at age 75 years (n = 36) according to the quintiles of a summary measure of concentrations of PCBs (vs. the lowest quintile) were 4.5, 5.1, 8.8 (1.8– 42.7), and 7.5 (1.4–38.8) (Ptrend ,0.01). Among organochlorine pesticides, adjusted ORs across concentrations of trans-nonachlor showed that Ptrend = 0.03. Adjusted ORs (95% CIs) across quintiles of the sum of three organochlorine pesticides were 1.1, 1.6, 1.5, and 3.4 (1.0–11.7) (Ptrend = 0.03). Neither brominated diphenyl ether 47 nor dioxin was significantly associated with incident diabetes. The sum of PCBs improved reclassification significantly when added to traditional risk factors for diabetes. CONCLUSIONS—Despite the small number of incident cases, this study found that envi- ronmental exposure to some POPs substantially increased risk of future type 2 diabetes in an elderly population.
    Diabetes care 06/2011; 34(8-8):1778-84. · 8.09 Impact Factor
  • Article: Polybrominated diphenyl ethers, polychlorinated biphenyls, and organochlorine pesticides in adipose tissues of Korean women.
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    ABSTRACT: Studies on residue levels and accumulation profiles of persistent organic pollutants (POPs) in human adipose tissues of Korean populations are scarce. In this study, concentrations and accumulation features of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs) were measured in adipose tissues of Korean women age 40-68 years. The highest concentrations were found for PCBs and DDTs, which were 1-2 orders of magnitude greater than the concentrations of hexachlorocyclohexanes, chlordanes, and PBDEs. The concentrations of PCBs and OCPs were lower than those reported for other countries. However, PBDE concentrations were greater than those reported for other countries, suggesting that ongoing exposure to PBDEs is a concern in Korea. The profiles of PBDEs were characterized by the predominance of BDE 209, followed by nona- and octa-BDEs, which are consistent with the consumption patterns of products containing PBDEs in Korea. The concentrations of PCBs and some OCPs were significantly correlated with each other, whereas PBDEs showed low or moderate correlations with other POPs, suggesting differences in exposure routes and biotransformation potentials of the compounds studied. The concentrations of organochlorines and PBDEs were not correlated with subjects' age and body mass index. The results of this study provide baseline information on POPs in adipose tissues of the general population in Korea.
    Archives of Environmental Contamination and Toxicology 05/2011; 62(1):176-84. · 1.93 Impact Factor
  • Article: Concentrations and accumulation profiles of PCDDs, PCDFs and dioxin-like PCBs in adipose fat tissues of Korean women.
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    ABSTRACT: Reports on residue levels and accumulation profiles of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in human adipose tissue are scarce in Korea. In this study, concentrations and accumulation features of PCDD/Fs and DL-PCBs were determined in the samples of adipose tissue collected from Korean women in 2007-2008. The total dioxin-like toxic equivalent (TEQ) concentrations (3.4-42 pg g(-1) lipid wt) in Korean adipose tissues were similar to those reported in European and other Asian countries. The relative contributions of individual compounds to total TEQs were as follows: non-ortho PCBs (mean: 45%) > PCDFs (28%) > PCDDs (24%) > mono-ortho PCBs (3%), a pattern similar to those reported for seafoods in Korea. The dominant PCDD/F congeners found in adipose tissues were OCDD and 2,3,4,7,8-PeCDF and dominant PCBs were 118, 156 and 105. No correlation was found between subject's age and concentrations of dioxin-like contaminants. Body mass index was not correlated with concentrations of PCDD/Fs and was negatively (p < 0.001) correlated with concentrations of DL-PCBs. The results of this study provide baseline information on PCDD/Fs and DL-PCBs in adipose tissues of the general population in Korea.
    Journal of Environmental Monitoring 02/2011; 13(4):1096-101. · 1.99 Impact Factor
  • Article: Estimating mobile network externality surcharges in Korea.
    Jongyong Lee, Duk Hee Lee
    IJMC. 01/2011; 9:584-603.
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    Article: Associations among organochlorine pesticides, Methanobacteriales, and obesity in Korean women.
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    ABSTRACT: Although Methanobacteriales in the gut has recently been linked to obesity, no study has examined the hypothesis that waist circumference, a marker of visceral obesity, are positively associated with Methanobacteriales in the general population. Since Methanobacteriales increase in a petroleum-contaminated environment to biodegrade petroleum as one way of autopurification, we also hypothesized that high body burden of highly lipophilic petroleum-based chemicals like organochlorine pesticides (OCPs) is associated with higher levels of Methanobacteriales in the gut. Among 83 Korean women who visited a community health service center for a routine health checkup, quantitative real-time PCR (qPCR) based on 16S rDNA was used to quantify Methanobacteriales in feces. Nine OCPs were measured in both serum and feces of 16 subjects. Methanobacteriales were detected in 32.5% (27/83 women). Both BMI and waist circumference among women with Methanobacteriales were significantly higher than in women without Methanobacteriales (P = 0.04 and P = 0.01, respectively). Also, Methanobacteriales levels in feces were positively associated with BMI and waist circumference (r = +0.23 and P = 0.03 for both). Furthermore, there were significant correlations between feces Methanobacteriales levels and serum concentrations of most OCPs, including with cis-nonachlor (r = +0.53, P<0.05), oxychlordane (r = +0.46, P<0.1), and trans-nonachlor (r = +0.43, P<0.1). Despite high correlations of serum and feces concentrations of most OCPs, feces OCP concentrations were not clearly associated with feces Methanobacteriales levels. In this cross-sectional study, the levels of Methanobacteriales in the human gut were associated with higher body weight and waist circumference. In addition, serum OCP concentrations were positively correlated with levels of Methanobacteriales. There may be a meaningful link among body burden of OCP, Methanobacteriales in the gut, and obesity in the general population.
    PLoS ONE 01/2011; 6(11):e27773. · 4.09 Impact Factor
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    Article: Low dose organochlorine pesticides and polychlorinated biphenyls predict obesity, dyslipidemia, and insulin resistance among people free of diabetes.
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    ABSTRACT: There is emerging evidence that background exposure to persistent organic pollutants (POPs) are important in the development of conditions predisposing to diabetes as well as of type 2 diabetes itself. We recently reported that low dose POPs predicted incident type 2 diabetes in a nested case-control study. The current study examined if low dose POPs predicted future adiposity, dyslipidemia, and insulin resistance among controls without diabetes in that study. The 90 controls were diabetes-free during 20 years follow-up. They were a stratified random sample, enriched with overweight and obese persons. POPs measured in 1987-88 (year 2) sera included 8 organochlorine (OC) pesticides, 22 polychlorinated biphenyls (PCBs), and 1 polybrominated biphenyl (PBB). Body mass index (BMI), triglycerides, HDL-cholesterol, LDL-cholesterol, and homeostasis model assessment value for insulin resistance (HOMA-IR) were study outcomes at 2005-06 (year 20). The evolution of study outcomes during 18 years by categories of serum concentrations of POPs at year 2 was evaluated by adjusting for the baseline values of outcomes plus potential confounders. Parallel to prediction of type 2 diabetes, many statistically significant associations of POPs with dysmetabolic conditions appeared at low dose, forming inverted U-shaped dose-response relations. Among OC pesticides, p,p'-DDE most consistently predicted higher BMI, triglycerides, and HOMA-IR and lower HDL-cholesterol at year 20 after adjusting for baseline values. Oxychlordane, trans-nonachlor, and hexachlorobenzene also significantly predicted higher triglycerides. Persistent PCBs with ≥7 chlorides predicted higher BMI, triglycerides, and HOMA-IR and lower HDL-cholesterol at year 20 with similar dose-response curves. Simultaneous exposure to various POPs in the general population may contribute to development of obesity, dyslipidemia, and insulin resistance, common precursors of type 2 diabetes and cardiovascular diseases. Although obesity is a primary cause of these metabolic abnormalities, POPs exposure may contribute to excess adiposity and other features of dysmetabolism.
    PLoS ONE 01/2011; 6(1):e15977. · 4.09 Impact Factor
  • Article: Low-dose persistent organic pollutants increased telomere length in peripheral leukocytes of healthy Koreans.
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    ABSTRACT: Although shortened telomeres have been found in many cancers, elongated telomere length has been observed as an early response after low-dose treatment with various chemical carcinogens in vitro and animal experiments, suggesting low-dose exposure to carcinogenic chemicals may function as a tumour promoter at the very early stage of carcinogenesis in humans. This cross-sectional study was performed to examine whether low-dose exposure to persistent organic pollutants (POPs), lipophilic xenobiotics that mainly bioaccumulate in adipose tissue, is associated with telomere length of peripheral blood leukocytes in apparently healthy persons. Telomere length was measured using quantitative polymerase chain reaction method in 84 apparently healthy Koreans. Among various POPs, serum concentrations of organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs) and polybrominated diphenylethers were measured. Most OC pesticides and PCBs were positively and significantly associated with telomere length with correlation coefficients from about +0.25 to +0.35. The strongest associations were observed with p,p'-dichlorodiphenyldichloroethylene, PCB99, PCB153, PCB180, PCB183 and PCB187. When we examined adjusted means of telomere length by quintiles of POPs, the steeper increases of telomere length tended to be observed within relatively lower ranges of POPs. Besides serum concentrations of POPs, none of the other variables studied, including age, were associated with telomere length in this study. We found that telomere length was increasing across low doses of exposure to POPs in which the majority of study subjects were found, suggesting that low-dose POPs may act as a tumour promoter in carcinogenesis in humans.
    Mutagenesis 09/2010; 25(5):511-6. · 3.18 Impact Factor
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    Article: Differential associations of weight dynamics with coronary artery calcium versus common carotid artery intima-media thickness: The CARDIA Study.
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    ABSTRACT: Change and fluctuation in body mass index (BMI; weight (kg)/height (m)(2)) may be associated differently with coronary artery calcification (CAC) than with carotid artery intima-media thickness (IMT). The authors analyzed data on 2,243 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) Study, initially aged 18-30 years, who were examined every 2-5 years over a 20-year period (1985-2006). BMI at year 0 was associated positively and linearly with CAC at year 20; however, the association of BMI with year 20 CAC became progressively U-shaped in subsequent examinations (years 10, 15, and 20). To understand the deepening U shape, the authors modeled year 20 BMI and its history using 3 indices: year 0 BMI, linear slope of BMI during 20 years, and BMI fluctuation during 20 years. In models including these 3 terms, year 0 BMI was associated positively with CAC, as was BMI fluctuation. However, adjusted odds ratios across quintiles of BMI slope (vs. the lowest quintile) were 0.7, 0.4, 0.5, and 0.4 (P(trend) < 0.01), suggesting higher risk of CAC with weight loss, plateauing after moderate weight gain. In contrast, IMT was associated positively with BMI at all examinations and with 20-year BMI slope and was unassociated with BMI fluctuation. Surprisingly, CAC risk was higher with BMI loss and lower with BMI gain, whereas associations with IMT were as expected.
    American journal of epidemiology 07/2010; 172(2):180-9. · 5.59 Impact Factor
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    Article: Low dose of some persistent organic pollutants predicts type 2 diabetes: a nested case-control study.
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    ABSTRACT: Low doses of some persistent organic pollutants (POPs) associate cross-sectionally with type 2 diabetes, whereas associations with high POP exposures are inconsistent. We investigated whether several POPs prospectively predict type 2 diabetes within the Coronary Artery Risk Development in Young Adults (CARDIA) cohort. Participants in this nested case-control study were diabetes free in 1987-1988. By 2005-2006, the 90 controls remained free of diabetes, whereas the 90 cases developed diabetes. Using serum collected in 1987-1988, we measured 8 organochlorine pesticides, 22 polychlorinated biphenyl congeners (PCBs), and 1 polybrominated biphenyl (PBB). We compared POP concentrations from CARDIA and the National Health and Nutrition Examination Survey (NHANES) in 2003-2004. We computed odds ratios (ORs) for incident diabetes using logistic regression analysis. Chlorinated POPs in CARDIA in 1987-1988 were much higher than corresponding NHANES 2003-2004 concentrations. POPs showed nonlinear associations with diabetes risk. The highest risk was observed in the second quartiles of trans-nonachlor, oxychlordane, mirex, highly chlorinated PCBs, and PBB153-a finding that suggests low-dose effects. We concentrated risk by summing these POPs and isolated very low concentrations of multiple POPs in the lowest sextile of the sum. The adjusted OR in the second sextile vs. the lowest sextile was 5.3 overall and 20.1 for body mass index > or = 30 kg/m2. Several POPs at low doses similar to current exposure levels may increase diabetes risk, possibly through endocrine disruption. Certain POPs may a play a role in the current epidemic of diabetes, which has been attributed to obesity.
    Environmental Health Perspectives 05/2010; 118(9):1235-42. · 7.04 Impact Factor
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    Article: Association of low-dose exposure to persistent organic pollutants with global DNA hypomethylation in healthy Koreans.
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    ABSTRACT: Global DNA methylation levels have been reported to be inversely associated with blood levels of persistent organic pollutants (POPs), xenobiotics that accumulate in adipose tissue. Whether these associations extend to a population with much lower concentrations of POPs is not known. This study was performed to examine whether low-dose exposure to POPs was associated with global DNA hypomethylation in Koreans. The amount of global DNA hypomethylation was estimated by the percent 5-methyl-cytosine (%5-mC) in Alu and LINE-1 assays in 86 apparently healthy Koreans. Among various POPs, organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs), and polybrominated diphenylethers (PBDEs) were measured. Most OC pesticides were inversely and significantly associated with %5-mC in the Alu assay, with correlation coefficients in the range 0.2 to 0.3 after adjusting for age, sex, body mass index, smoking, and alcohol. The strongest OC pesticide associations with %5-mC in the Alu assay were observed with oxychlordane, trans-nonachlor, and p,p -dichlorodiphenyldichloroethylene. The correlation coefficient of age with %5-mC in the Alu assay was 0.24, similar to correlations of OC pesticides with %5-mC in the Alu assay. Most PCBs and PBDEs showed nonsignificant inverse trends with %5-mC in the Alu assay, but for some PCBs the U-shaped association was significant. On the other hand, POPs were not associated with %5-mC in the LINE-1 assay. We found that low-dose exposure to POPs, in particular OC pesticides, was associated with global DNA hypomethylation in apparently healthy Koreans.
    Environmental Health Perspectives 03/2010; 118(3):370-4. · 7.04 Impact Factor
  • Article: Relationship between cardiovascular autonomic neuropathy and coronary artery calcification in patients with type 2 diabetes.
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    ABSTRACT: To test the hypothesis that cardiovascular autonomic neuropathy (CAN) in Type 2 diabetes is a risk factor of coronary artery calcification (CAC), in this cross-sectional study, 118 patients (60 males, 58 females) with type 2 diabetes mellitus were randomly selected from the diabetes clinic of Kyungpook National University Hospital, Daegu, Korea, between January, 2008 and September, 2008. The subjects, whose mean age was 56.9+/-1.1 years, were tested for CAN by Ewing's method which employs five non-invasive tests of autonomic function. The coronary calcium score (CCS) was determined by Multi Detector-row Computed Tomography (MDCT). Statistical analysis was performed by using SPSS 13.0 (SPSS, Inc., Chicago,-Illinois). CAN was found in 31/118 (26.3%) patients. Compared to the patients without CAN, the patients with CAN were significantly older and had significantly higher triglyceride levels, blood pressure, pulse pressure, fasting c-peptide levels, CAN scores, and log-transformed coronary calcium scores [ln(CCS+1)]. The CAN scores correlated positively with ln(CCS+1) values (r = 0.214; P = 0.028). Multiple regression analysis using ln(CCS+1) as a dependent variable showed that CAN score (beta coefficient 0.623, 95% CI 0.059 approximately 1.188, P = 0.031) associated independently with ln(CCS+1). In conclusion, CAN was associated independently with CAC, which suggests that CAN is a risk factor of coronary atherosclerosis in patients with type 2 diabetes. This may help to explain the excess cardiovascular mortality seen in diabetic patients with CAN.
    Endocrine Journal 02/2010; 57(5):445-54. · 2.03 Impact Factor

Institutions

  • 2012
    • Uppsala University
      Uppsala, Uppsala, Sweden
    • National Cancer Center Korea
      Goyang, Gyeonggi, South Korea
    • Kyungpook National University Hospital
      Seoul, Seoul, South Korea
  • 2004–2012
    • Kyungpook National University
      • • Department of Preventive Medicine
      • • School of Medicine
      Sangju, North Gyeongsang, South Korea
  • 2011
    • Hanyang University
      Ansan, Gyeonggi, South Korea
  • 2004–2009
    • University of Minnesota Twin Cities
      • • Division of Epidemiology and Community Health
      • • Department of Laboratory Medicine and Pathology
      • • School of Public Health
      Minneapolis, MN, USA
  • 2008
    • KU Leuven
      • Division of Artherosclerosis and Metabolism
      Leuven, VLG, Belgium
  • 2006
    • University of Oslo
      • Department of Nutrition
      Oslo, Oslo, Norway
  • 2002–2003
    • Kosin University
      Pusan, Busan, South Korea