Duk-Hee Lee

Vitamin D is important because it has roles in maintaining musculoskeletal health, redox homeostasis, and the immune system; however, it is commonly dysregulated by endocrine disrupting chemicals, particularly phthalates and bisphenol A (BPA). Continuous exposure to phthalates and BPA may alter the endogenous metabolite profiles associated with vitamin D activity, although the specific metabolites are yet to be identified. In this study, we identified the endogenous metabolites altered by phthalates and BPA exposure through untargeted metabolic profiling and investigated the role of these metabolites in vitamin D activity. Plasma metabolic profiling using liquid chromatography-mass spectrometry was performed in two groups: severe 25-hydroxyvitamin D (25(OH)D) deficiency and high exposure to phthalates and BPA (Group A) and 25(OH)D deficiency and low exposure to phthalates and BPA (Group B …

Recently, both weight loss and weight gain were associated with an increased risk of cardiovascular disease (CVD) and allcause mortality among over 1.5 million Korean patients with type 2 diabetes mellitus, indicating a clear U-shaped association 1. While the poor prognosis in patients with weight gain was in line with the current paradigm of obesity, the increased risk of CVD and death in patients with weight loss seemed counterintuitive. The authors interpreted this as surprising because of the well-known benefits of weight loss to cardiometabolic profiles and provided several methodological explanations such as loss of lean mass, body weight fluctuation, or unintentional weight loss 1. However, the dynamics of lipophilic pollutants stored in adipose tissue may be involved in the U-shaped association between weight change and poor prognosis among patients with type 2 diabetes mellitus.

Persistent organic pollutants (POPs) are lipophilic environmental toxins, and the level of chemicals accumulated in the body through the food chain has been linked to the incidence of diseases such as type 2 diabetes, cardiovascular disease, and cancer. We analyzed the concentration of POPs and circulating metabolites and investigated the associations between the concentration of plasma metabolites and the levels of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) to determine the effect of the accumulation of POPs in human samples. Metabolic profiling of plasma from 276 Korean participants was performed using 1H nuclear magnetic resonance (NMR) and statistical analyses. The concentrations of PCBs and OCPs in each sample were measured. Correlation analysis and a covariate-adjusted general linear model (GLM) were used to investigate the association of the concentration of …

I have read the article by Lee et al. 1 with great interest. This article reported favourable post-operative overall survival among obese patients with lung adenocarcinoma, a phenomenon known as the obesity paradox. Besides lung cancer, a better prognosis among overweight or obese patients has been repeatedly observed among patients with a broad range of diseases. For example, in 2021, this journal published several articles regarding the obesity paradox among patients with stroke, 2 sepsis, 3 and heart failure. 4 Among several possible explanations for the obesity paradox, the methodological limitation of body mass index (BMI) as a marker of obesity has been considered a major underlying mechanism. 5 BMI does not delineate adipose tissue distribution or distinguish between fat and lean body mass. Thus, body composition phenotypes have been considered as missing links in the obesity paradox. 6 …

BackgroundChronic exposure to low-dose persistent organic pollutants (POPs) can induce mitochondrial dysfunction. This study evaluated the association between serum POP concentrations and oxygen consumption rate (OCR) as a marker of mitochondrial function in humans and in vitro cells.MethodsSerum concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were measured in 323 adults. The OCRs of platelets and peripheral blood mononuclear cells (PBMCs) were assessed in 20 mL of fresh blood using a Seahorse XF analyzer. Additionally, the in vitro effects of Arochlor-1254, β-hexachlorocyclohexane, and p, p′-dichlorodiphenyltrichloroethane at concentrations of 0.1 pM to 100 nM were evaluated in human platelets, human PBMCs, and Jurkat T-cells.ResultsThe association between serum POP concentrations and OCR differed depending on the cell type. As serum …

The Alzheimer’s Management by Albumin Replacement (AMBAR) trial demonstrated the clinical efficacy of plasma exchange (PE) with albumin replacement for slowing the progression of disease in patients with mild-to-moderate Alzheimer’s disease (AD). 1, 2 Although the main hypothesized mechanism in AMBAR was a decrease in neurotoxic amyloid beta (Aβ) amount, its quantification in the cerebrospinal fluid revealed no clear evidence in this regard, implying the presence of alternative mechanisms beyond Aβ binding. At present, the elimination of dysfunctional albumin, inflammatory mediators, neurotoxic autoantibodies, and other pro-aging-related proteins have been proposed as possible underlying mechanisms. 3 Importantly, PE can effectively remove persistent organic pollutants (POPs) that have recently emerged as a novel risk factor for dementia. 4, 5 Human adipose tissue is contaminated by a large …

Preventive & Social Medicine chemicals, including POPs, impair the immune system at high doses. 11, 12 Exposure to 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) induces several immunotoxic effects on both innate and adaptive immune responses through aryl hydrocarbon receptors. 13, 14 In a previous study, TCDD administration to laboratory animals resulted in decreased resistance to numerous bacteria, viruses, and parasites. 15 In addition to TCDD, other POPs, classified as organochlorine pesticides, polychlorinated biphenyls, and polybrominated diphenyl ethers, have also demonstrated immunotoxicity in many in vitro and in vivo studies. 16-18Early toxicological studies have focused on the immunotoxicity of high doses of individual chemicals; however, recent studies have highlighted the effect of chronic exposure to lowdose environmental pollutants on the immune system. 19, 20 In contemporary …

BackgroundLow-dose persistent organic pollutants (POPs), especially organochlorine pesticides (OCPs), have emerged as a new risk factor of many chronic diseases. As serum concentrations of POPs in humans are mainly determined by both their release from adipose tissue to circulation and their elimination from circulation, management of these internal pathways may be important in controlling the serum concentrations of POPs. As habitual physical activity can increase the elimination of POPs from circulation, we evaluated whether chronic physical activity is related to low serum POP concentrations.MethodsA cross-sectional study of 1,850 healthy adults (age≥ 20 years) without cardio-metabolic diseases who participated in the US National Health and Nutrition Examination Survey 1999 to 2004 was conducted. Information on moderate or vigorous leisure-time physical activity was obtained based on questionnaires. Serum concentrations of OCPs and polychlorinated biphenyls were investigated as typical POPs.ResultsSerum concentrations of OCPs among physically active subjects were significantly lower than those among physically inactive subjects (312.8 ng/g lipid vs. 538.0 ng/g lipid, P< 0.001). This difference was maintained after adjustment for potential confounders. When analyses were restricted to physically active subjects, there were small decreases in the serum concentrations of OCPs with increasing duration of physical activity, showing a curvilinear relationship over the whole range of physical activity (P quadratic< 0.001). In analyses stratified by age, sex, body mass index, and smoking status, a strong inverse association …

The prevailing strategy against COVID-19 is to suppress transmission until vaccine development is completed. However, the development of effective and safe vaccines, especially for RNA viruses, is difficult and often requires a long time. Additionally, in the case of infectious diseases such as COVID-19, which have a high proportion of asymptomatic or mildly symptomatic patients with a high transmission rate, the effectiveness of suppressing transmission is limited. Therefore, rather than the one-size-fits-all approach, I suggest a two-track approach involving a suppression strategy for the high-risk group and an immunity-based strategy for the low-risk group. The key concepts of the immunity-based strategy are cross-immunity and herd immunity. Although the original concept of herd immunity was comprehensive and closely related to cross-immunity, it has shrunk to just a threshold of specific antibodies against specific pathogens since the advent of vaccines. We need to incorporate these two concepts into an effective public health strategy against the COVID-19 epidemic as well as future epidemics of other emerging infectious diseases.

ObjectivesThis study was conducted to explore recent trends in the prevalence of pediatric elevated blood pressure and hypertension (HTN) in Korea and the United States, applying the new HTN reference values for adolescents.MethodsThis study analyzed 17 339 (8755 Korean and 8584 American) adolescents aged 10 to 17 who participated in the Korea National Health and Nutrition Examination Survey and the National Health and Nutrition Examination Survey, respectively, between 2005 and 2016. HTN was defined using percentile-based reference values for non-overweight adolescents from 7 nations, and obesity was defined by body mass index (BMI) based on country-specific growth charts. All analyses were stratified by sex and year-over-year changes were evaluated by calculating the p for trend.ResultsSystolic blood pressure showed a statistically meaningful upward trend in Korean boys and girls …

We have read with a great interest the article written by Song and colleagues 1 assessing seroprevalence of coronavirus disease 2019 (COVID-19) in Daegu, Korea, aftermath of the largest epicenter in Korea. The study is in line with previous assumptions that there may had been a large transmission of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) resulting asymptomatic infection in the general population. However, a few points should be clarified prior to drawing conclusions.First, the performance of the antibody assay that was used in the study should be noted. The clinical specificity of assays should be vigorously evaluated before applying to the large-scale evaluation of a population. The authors described the specificity of the assay as 92%, which the number may not be drawn from 30 specimens. If the specificity is 92%, which means that false-positive rate is 8%, the prevalence of 7.6% can be attributed to false-positive results, not from past-infection. The authors have assumed that moderate performance is acceptable in estimating the seroprevalence in population. However, even if the performance obtained from study is adequate, the application of the assay into general population should be cautious. The positive predictive value of diagnostic assays is affected by the disease prevalence. 2 Low prevalence may result in a high false positive rate, or a low positive predictive value, vice versa.

Introduction While type 2 diabetes (T2D) has been associated with increased all-cause mortality among women diagnosed with breast cancer (BC), the association between T2D and breast cancer-specific (BCS) mortality is unresolved. The goal of this study was to examine the association between T2D and BCS mortality and examine the influence of metformin treatment on mortality rates. Methods A retrospective cohort study was conducted between 2002 and 2008 at Emory University Hospitals among non-Hispanic black and white women who had confirmed diagnosis of stage I-III BC and known diabetes status (T2D: n = 73; non-T2D: n = 514). Cox proportional hazard models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI). Results Compared to non-T2D patients, T2D women had almost a 2-fold increase in BCS mortality after adjusting for covariates (HR = 2.01; 95%CI = 1.02–3.98). Though attenuated, the increased hazard of death was also observed for all-cause mortality (HR = 1.74; 95%CI = 1.06–2.87). T2D patients who were not on metformin had substantially higher hazard of BCS mortality compared to non-diabetic patients (HR = 4.54; 95%CI = 1.98–10.44), whereas the association among T2D patients treated with metformin was weak (HR = 1.20; 95%CI = 0.36–3.97) and included the null. Conclusions Among women with BC, T2D is associated with increased BCS mortality. Metformin treatment for T2D during the initial diagnosis of BC may improve outcomes.

Objective The aim of this paper is to propose a new hypothesis for the role of lipophilic chemical mixtures stored in adipose tissue in the development of dementia. Specifically, we present how the dynamics of these chemicals can explain the unexpected findings from the Action for Health in Diabetes (Look AHEAD) study, which failed to show long‐term benefits of intentional weight loss on cognition, despite substantial improvements in many known risk factors for dementia. Moreover, we discuss how the role of obesity in the risk of dementia can change depending on the dynamics of these chemicals in adipose tissue. New hypothesis Human adipose tissue is widely contaminated with various neurotoxic chemicals. Typical examples are persistent organic pollutants (POPs), strong lipophilic chemicals with long half‐lives. Both unintentional and intentional weight loss increases the release of POPs from adipocytes …

BackgroundSeroprevalence studies of coronavirus disease 2019 (COVID-19) from many countries have shown that the number of undiagnosed missing cases is much larger than that of confirmed cases, irrespective of seroprevalence levels. Considering the strategy of Korea entailing massive testing and contact tracing from the beginning of epidemic, the number of undiagnosed missing cases in Korea may be negligible. This study was conducted to estimate the seroprevalence of COVID-19 among individuals who were never diagnosed with COVID-19 in Daegu, the epicenter of COVID-19 epidemic in Korea.MethodsSerologic testing for immunoglobulin G antibody based on immunochromatographic assay was conducted in 103 patients and 95 guardians aged 18 to 82 years without any history of COVID-19 diagnosis, who visited outpatient clinics of a single university-affiliated hospital from May 25 to June 5 …

Can habitual exercise really increase serum concentrations of persistent organic pollutants? Can habitual exercise really increase serum concentrations of persistent organic pollutants? Environ Int. 2020 Jul;140:105615. doi: 10.1016/j.envint.2020.105615. Epub 2020 Mar 14. Authors Yu-Mi Lee 1 , Duk-Hee Lee 2 Affiliations 1 Department of Preventive Medicine, School of Medicine, Kyungpook National University, Daegu, Republic of Korea. 2 Department of Preventive Medicine, School of Medicine, Kyungpook National University, Daegu, Republic of Korea; BK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science, Kyungpook National University, Republic of Korea. Electronic address: lee_dh@knu.ac.kr. PMID: 32183987 DOI: 10.1016/j.envint.2020.105615 No abstract available Publication types Letter Research Support, Non-US Gov't Comment MeSH terms Adolescent Child …

In the general population, chronic exposure to low-dose persistent organic pollutants (POPs), particularly organochlorine pesticides (OCPs), has been recently linked to many chronic diseases. Widespread contamination of the food chain and human adipose tissue has made avoiding exposure to these chemicals impossible; thus, alternative strategies for decreasing the chemical burden must be investigated. Recently, macronutrient intake was found to significantly modify the toxicokinetics of POPs in animal experimental studies. Thus, we evaluated whether macronutrient intake was related to serum concentrations of OCPs in healthy adults without cardio-metabolic diseases. Subjects included 1,764 adults, aged 20 years or above, who participated in the National Health and Nutrition Examination Survey 1999–2004. Macronutrient intake was assessed based on a 24-h dietary recall interview. Six individual OCPs …

BackgroundLack of sunlight exposure is the primary reason for the worldwide epidemic of vitamin D deficiency. Although recommended sunlight exposure guidelines exist, there is no evidence regarding whether current guidelines are optimal for increasing vitamin D levels among individuals with vitamin D deficiency.MethodsSixty Korean adults aged 20–49 years with serum 25-hydroxyvitamin D (25 [OH] D) levels of< 20 ng/mL were randomly assigned to three groups: sunlight exposure (n= 20), vitamin D supplementation groups (n= 20), and daily living (n= 20) for 1 month. The sunlight exposure group had sunlight exposure on 20% to 30% of their body surface areas for 30–60 minutes per day, 3 times a week during the summer season. Vitamin D supplementation was prescribed with 800 IU/day of vitamin D. The serum levels of 25 (OH) D were measured at baseline and at 1-month follow-up examinations.Results …

PurposePositive relationships between persistent organochlorine pollutants and cardiovascular disease have been suggested. We hypothesized that pollutants measured in young adulthood associate positively with incident cardiovascular disease in 30-year follow-up.MethodsA nested case control study examined pollutants and diabetes, assaying chemicals in blood serum from 1987-88 (year 2) among 90 who developed diabetes by 2005 (Coronary Artery Risk Development in Young Adults Study year 20) and 90 who did not. 32 pollutants were included: 8 organochlorine pesticides, 23 polychlorinated biphenyls, 1 polybrominated biphenyl. Cardiovascular events, assessed annually through 2018, include coronary heart disease, hospitalized heart failure, stroke, transient ischemic attack, and peripheral arterial disease. Cox proportional hazards models were adjusted for year 2 age, sex, race, and triglycerides …

Intentional weight loss can increase health risk in the long‐term, despite short‐term benefits, because human adipose tissue is widely contaminated with various lipophilic environmental contaminants, especially persistent organic pollutants (POPs). Recently, chronic exposure to low POPs has emerged as a new risk factor for common metabolic diseases and cardiovascular diseases. The amount of POPs released from adipocytes to the circulation increases during weight loss, thereby increasing POPs exposure of other critical organs. Possible harmful effects due to release of POPs during weight loss are opposite to those usually expected from losing weight. It is speculated that this tradeoff can explain recent puzzling findings on intensive weight loss. The presence of POPs in adipose tissue adds a challenge to weight management and an optimal strategy of weight management needs to consider both fat mass …

Letter to the Editor: Effect of fatty fish or nut consumption on concentrations of persistent organic pollutants in overweight or obese men and women: A randomized controlled clinical trial. - Abstract - Europe PMC Sign in | Create an account https://orcid.org Europe PMC Menu About Tools Developers Help Contact us Helpdesk Feedback Twitter Blog Tech blog Developer Forum Europe PMC plus Search life-sciences literature (42,156,827 articles, preprints and more) Search Advanced search Feedback This website requires cookies, and the limited processing of your personal data in order to function. By using the site you are agreeing to this as outlined in our privacy notice and cookie policy. Abstract Full text Funding Letter to the Editor: Effect of fatty fish or nut consumption on concentrations of persistent organic pollutants in overweight or obese men and women: A randomized controlled clinical trial. Lee YM 1 , Lee …