Ability to pay and catastrophic health expenditure of urban and rural deceased households over the past decade (2009-2018).

INTRODUCTION: Examining the equity of health care and financial burden in households of deceased individuals in urban and rural areas is crucial for understanding the risks to both national and individual household finances. However, there is a lack of research on catastrophic health expenditure (CHE) in these households, specifically in urban and rural contexts. This study aims to identify the ability to pay and equity of CHE for both households of deceased individuals in urban and in rural areas. METHODS: This study analysed data from the Korea Health Panel for 10 years (2009-2018) and targeted 869 deceased individuals and their households in the Republic of Korea (South Korea). Annual household income and living costs were adjusted based on equivalent household size, and the difference between these values represented the household's ability to pay. Out-of-pocket (OOP) expenditure included copayments and uninsured healthcare expenses for emergency room visits, inpatient care, outpatient treatments and prescription medications. CHE was defined as OOP expenditure reaching or exceeding 40% of the household's ability to pay. ANCOVA was performed to control for confounding variables, and the equity of CHE prevalence between urban and rural area was assessed using χ2 analysis. RESULTS: Compared to urban households, the rural households of deceased individuals had, respectively, fewer members (2.7 v 2.4, p=0.03), a higher rate of presence of a spouse (63.8% v 70.7%, p=0.04) and a higher economic activity rate (12.7% v 20.5%, p=0.002). The mean number of comordities before death was 3.7 in both urban and rural areas, and there was no difference in the experience of using over-the-counter medicines for more than 3 months, emergency room, hospitalisation, and outpatient treatment. In addition, annual household OOP expenditures in urban and rural areas were US$3020.20 and US$2812.20, respectively, showing no statistical difference (p=0.341). This can be evaluated as a positive effect of various policies and practices aimed at alleviating urban-rural health equity. However, the financial characteristics of the household of the deceased in the year of death differed decisively between urban and rural areas. Compared to urban households, the annual income of rural households (US$15,673.80 v US$12,794.80, respectively, p≤0.002) and the annual ability to pay of rural households (US$14,734.10 v US$12,069.30, respectively, p=0.03) were lower. As a result, the prevalence of CHE was higher in rural areas than in urban areas (68.3% v 77.6%, p=0.003). CONCLUSION: The findings of this study highlight the higher risk of CHE in rural areas due to the lower income level and ability to pay of the household of the deceased. It is evident that addressing the issue of CHE requires broader social development and policy efforts rather than individual-level interventions focused solely on improving health access and controlling healthcare costs. The findings of this study contribute to the growing evidence that income plays a crucial role in rural health outcomes.

Socioeconomic class and antenatal and postpartum care inequality in the viewpoint of Korea's response to the low fertility rate.

The author pays attention to the low total fertility rate (0.78 in Korea in 2022) and inequality in antenatal and postpartum care between socioeconomic classes. I analyzed the data of the Korea Health Panel (2008-2016), 1,196 postpartum women. Low-income households have low fertility rates and less experience with antenatal and postpartum care, and postpartum care costs tend to be time-series lower than others. In order to solve the problem of low fertility due to economic burden, policy governance should focus on equity in antenatal and postpartum care. This is to go beyond women's health and ultimately contribute to social health.

Household catastrophic health expenditure related to pain in Korea.

Background: The data related to pain and catastrophic health expenditure (CHE) needed to be further explored. This study aims to understand the relationship between pain and CHE. Methods: Using cross-sectional analysis of 4-year data (2015-2018) from the Korea Health Panel, the prevalence of CHE and adjusted odds ratio (AOR) by pain type were confirmed. Results: Among participants (n = 46,597), the prevalence of pain and severe pain were 24.2% and 1.1%, respectively. The use of medical services in emergency rooms, hospitalizations, and outpatients increased in the order of pain-free, pain, and severe pain (P < 0.001). Prevalence of household CHE was 3.3% vs. 11.1% vs. 25.9%, (P < 0.001). The AOR of CHE was 1.5 (95% confidence interval [CI], 1.4-1.7) for pain and 3.1 (95% CI, 2.5-3.9) for severe pain. Household capacity to pay per year was lower and lower in the order of pain-free, pain, and severe pain ($25,094 vs. $17,965 vs. $14,056, P < 0.001). Also, the household out-of-pocket expenditure per year was higher and higher in the order of pain-free, pain, and severe pain ($1,649, $1,870, $2,331, P < 0.001). Conclusions: It can be inferred that pain is one of the mechanisms of poverty. Positivist healthcare policies for the prevention and management of pain should be sought.

Time Series Trend in High BMI and High Out-of-Pocket Expenditure Among Women With Disability.

Health with disability is directly related not only to an individual's quality of life but also to national medical finance. This study focuses on trends in BMI and out-of-pocket (OOP) expenditure of both types of indirect cost exclusion and inclusion. Participants were women with disability (n = 3200) and women without disability (n = 53 082) among adults aged 19 and older from Korea Health Panel from 2009 to 2016. Women with disability had a higher BMI (23.9) than women without disability (22.7), and this time series trend was significant for 8 years (P < .0001). Annual OOP expenditures of both types were higher for women with disability than for women without disability (P < .0001): excluding indirect costs, $518.9 versus $649.4; Including indirect costs, $534.5 versus $681.8. The y-intercept of disability itself and slope of one unit of BMI for both types of annual OOP expenditure is significant (P < 0001): excluding indirect cost, $29.0 and $4.4; including indirect cost, $35.2 versus $4.6. In women with disability, annual OOP expenditure for both types were higher when they were physically inactive (P < .05): excluding indirect cost, $714.1 versus $823.1; including indirect cost, $746.2 versus $880.0. When physical inactivity and overweight and obesity interacted, it increased more than normal weight in dose response manner (P < .05): excluding indirect costs, $799.2 < $800.3 < $886.1; Including indirect costs, $860.2 < $845.9 < $927.5. These results suggest that women with disability are in relatively poor health. It is proposed that inequality of BMI for women with disability can be developed as an agenda from health policy.

A Retro-Aldol Reaction Prompted the Evolvability of a Phosphotransferase System for the Utilization of a Rare Sugar.

The evolution of the bacterial phosphotransferase system (PTS) linked to glycolysis is dependent on the availability of naturally occurring sugars. Although bacteria exhibit sugar specificities based on carbon catabolite repression, the acquisition and evolvability of the cellular sugar preference under conditions that are suboptimal for growth (e.g., environments rich in a rare sugar) are poorly understood. Here, we generated Escherichia coli mutants via a retro-aldol reaction to obtain progeny that can utilize the rare sugar d-tagatose. We detected a minimal set of adaptive mutations in the d-fructose-specific PTS to render E. coli capable of d-tagatose utilization. These E. coli mutant strains lost the tight regulation of both the d-fructose and N-acetyl-galactosamine PTS following deletions in the binding site of the catabolite repressor/activator protein (Cra) upstream from the fruBKA operon and in the agaR gene, encoding the N-acetylgalactosamine (GalNAc) repressor, respectively. Acquired d-tagatose catabolic pathways then underwent fine-tuned adaptation via an additional mutation in 1-phosphofructose kinase to adjust metabolic fluxes. We determined the evolutionary trajectory at the molecular level, providing insights into the mechanism by which enteric bacteria evolved a substrate preference for the rare sugar d-tagatose. Furthermore, the engineered E. coli mutant strain could serve as an in vivo high-throughput screening platform for engineering non-phosphosugar isomerases to produce rare sugars. IMPORTANCE Microorganisms generate energy through glycolysis, which might have preceded a rapid burst of evolution, including the evolution of cellular respiration in the primordial biosphere. However, little is known about the evolvability of cellular sugar preferences. Here, we generated Escherichia coli mutants via a retro-aldol reaction to obtain progeny that can utilize the rare sugar d-tagatose. Consequently, we identified mutational hot spots and determined the evolutionary trajectory at the molecular level. This provided insights into the mechanism by which enteric bacteria evolved substrate preferences for various sugars, accounting for the widespread occurrence of these taxa. Furthermore, the adaptive laboratory evolution-induced cellular chassis could serve as an in vivo high-throughput screening platform for engineering tailor-made non-phosphorylated sugar isomerases to produce low-calorigenic rare sugars showing antidiabetic, antihyperglycemic, and antitumor activities.

Comparison of out-of-pocket expenditure and catastrophic health expenditure for severe disease by the health security system: based on end-stage renal disease in South Korea.

BACKGROUND: Korea's health security system named the National Health Insurance and Medical Aid has revolutionized the nation's mandatory health insurance and continues to reduce excessive copayments. However, few studies have examined healthcare utilization and expenditure by the health security system for severe diseases. This study looked at reverse discrimination regarding end-stage renal disease by the National Health Insurance and Medical Aid. METHODS: A total of 305 subjects were diagnosed with end-stage renal disease in the Korea Health Panel from 2008 to 2013. Chi-square, t-test, and ANCOVA were conducted to identify the healthcare utilization rate, out-of-pocket expenditure, and the prevalence of catastrophic expenditure. Mixed effect panel analysis was used to evaluate total out-of-pocket expenditure by the National Health Insurance and Medical Aid over a 6-year period. RESULTS: There were no significant differences in the healthcare utilization rate for emergency room visits, admissions, or outpatient department visits between the National Health Insurance and Medical Aid because these healthcare services were essential for individuals with serious diseases, such as end-stage renal disease. Meanwhile, each out-of-pocket expenditure for an admission and the outpatient department by the National Health Insurance was 2.6 and 3.1 times higher than that of Medical Aid (P < 0.05). The total out-of-pocket expenditure, including that for emergency room visits, admission, outpatient department visits, and prescribed drugs, was 2.9 times higher for the National Health Insurance than Medical Aid (P < 0.001). Over a 6-year period, in terms of total of out-of-pocket expenditure, subjects with the National Health Insurance spent more than those with Medical Aid (P < 0.01). If the total household income decile was less than the median and subjects were covered by the National Health Insurance, the catastrophic health expenditure rate was 92.2%, but it was only 58.8% for Medical Aid (P < 0.001). CONCLUSION: Individuals with serious diseases, such as end-stage renal disease, can be faced with reverse discrimination depending on the type of insurance that is provided by the health security system. It is necessary to consider individuals who have National Health Insurance but are still poor.

Disease Burden of the Kidney Disabled in Korea, 2009-2013: The Gap with That of the Non-Kidney Disabled Continues.

Kidney disability due to kidney failure could be considered to be the most severe of all the internal-organ disabilities. The purpose of this study was to identify the disease burden between the kidney and non-kidney disabled among the internal-organ disabled, based on the number of chronic diseases, annual out-of-pocket expenditure, and quality of life. From 2009 to 2013, 308 people (6.5%) with internal-organ disabilities were extracted out of 4732 people with disabilities in the Korea Health Panel. We compared the disease burden of 136 people with kidney disability (44.2%) and 172 people with non-kidney disability (55.8%), and confirmed the trend of disease burden over five years through panel analysis. The disease burden gap between kidney and non-kidney disabilities was, respectively, the number of chronic diseases (4.7 vs. 3.3, p < 0.0001), annual out-of-pocket expenditure ($1292 vs. $847, p < 0.004), and quality of life score out of 100 (49.2 vs. 60.2, p < 0.0001). In addition, when looking at the five-year trend of the three disease burden indexes, the kidney disabled were consistently worse than the non-kidney disabled (p < 0.01). In conclusion, health policy planners aiming for health equity need to seek practical strategies to reduce the gap in the disease burden among people with disabilities.

Association between domperidone use and adverse cardiovascular events: A nested case-control and case-time-control study.

PURPOSE: To assess the association between domperidone and adverse cardiovascular events. METHODS: We conducted nested case-control and case-time-control studies using Korea's healthcare database (2002-2015). We identified patients without history of hospitalization, cancer, or cardiovascular diseases in 2002. From our cohort, those diagnosed with an adverse cardiovascular event (case), composite of arrhythmia, hypertension, or acute myocardial infarction were matched to two controls using risk-set sampling on various sociodemographic variables. Exposure was assessed in the 1 to 7 days, or in the 1 to 7 days (hazard period) and 91 to 97 days (control period) prior to index date, in nested case-control and case-time control studies, respectively. We compared domperidone to metoclopramide or non-use and estimated odds ratios (OR) with 95% confidence intervals (CI) using conditional logistic regression. RESULTS: From 627 799 patients, we identified 71 555 cases and 141 833 controls. In the nested case-control study, while the risk of cardiovascular events was increased with domperidone (OR 1.38, 95% CI 1.28-1.47) compared to non-use, the risk was reduced (0.64, 0.57-0.72) compared to metoclopramide. In the case-time-control study, similar increased risk was found when compared to non-use (1.40, 1.29-1.52) but a reduced risk as compared with metoclopramide (0.63, 0.54-0.72). Risk of myocardial infarction associated with domperidone was highest (nested case-control: 1.94, 1.33-2.83; case-time-control: 1.91, 1.01-3.62) when compared to non-use but did not indicate an increased risk when compared to metoclopramide (nested case-control: 0.60, 0.32-1.13; case-time-control: 0.70, 0.25-1.98). CONCLUSION: Our findings support a positive association between domperidone and adverse cardiovascular events. However, domperidone may have a safer cardiovascular profile than metoclopramide.

Associations of Food-Chewing Discomfort with Health Behaviors and Cognitive and Physical Health Using Pooled Data from the Korean Health Panel (2010-2013).

Using 4 years of pooled data from the Korean Health Panel (2010-2013), the prevalence of food-chewing discomfort in adults over the age of 19 was investigated and the cross-sectional relationship between food-chewing discomfort and health behaviors and cognitive and physical health was identified. The prevalence of food-chewing discomfort was 31%: young adults (<40 years), 17.9%; middle-aged adults (40-64 years), 28.9%; and older adults (≥65 years), 57.1% (p < 0.0001). When food-chewing discomfort was sometimes, often, or always rather than never, odds ratios (ORs) were analyzed after controlling for sociodemographic characteristics. Significant OR results of target variables were smoking (OR 1.15, 1.37, 1.50), drinking (1.08, 0.87, 0.73), problem drinking (1.87, 1.67, 1.34), abstinence from drinking (1.23, 1.34, 1.42), nonphysical activity (OR 0.87 only significant, 0.94 nonsignificant, 1.10 nonsignificant), memory decline (2.07, 2.56, 3.31), decision-making difficulty (1.76, 2.78, 4.37), limitation of daily life due to illness (2.29, 3.60, 3.92), and the presence of a chronic disease (1.28, 1.62, 1.73), respectively. In conclusion, there were associations of food-chewing discomfort with increased smoking and decreased alcohol consumption, with increased difficulty in decision-making and memory decline, limitations in daily life due to disease, and the presence of chronic diseases. Therefore, it is necessary to investigate the causal relationship between chewing and health behaviors and cognitive and physical health through longitudinal studies.

The Influence of Pain on Frailty among the Elderly: Based on Korea Health Panel.

BACKGROUND: Interests between pain and frailty have been increasing in aging or aged societies. This study aimed to identify the prevalence of pain and frailty and to find the influence of pain on frailty. METHODS: Subjects were selected with aged 65 yr or older among pooled Korea Health Panel data from 2009 to 2013. The prevalence of pain was determined by combining some pain and extreme pain and also, frailty was defined when subjects had at least one of the following 6-domain frailty: physical inactivity, mobility reduction, dependence of daily life, depression, multimorbidity, and disability. RESULTS: The prevalence of pain and frailty was 56.1% and 59.8%. It was significantly higher in female (66.1% and 65.2%) and the oldest-old (69.4% and 71.8%). After adjusting for gender, age group, spouse, illiteracy, and economic activity, odds ratios of frailty for some pain and extreme pain were 2.8 (95% CI 2.6-3.0) and 10.5 (95% CI 8.0-13.8) in total subjects. The odds ratios of each 6-domain frailty for some and extreme pain were also significant. Among them, mobility reduction was 5.1 (95% CI 4.5-5.8) and 16.5 (95% CI 13.6-20.1), and dependence of daily life was 3.9 (95% CI 3.5-4.5) and 12.4 (95% CI 10.2-15.1). CONCLUSION: Among the elderly, prevalence of frailty (59.8%) was somewhat higher than that of pain (56.1%). Female and oldest-old had higher prevalence of pain and frailty. In addition, some pain and extreme pain had a decisive influence on frailty and each 6-domain frailty. Therefore, pain control is essential to prevent or manage frailty.

Physician and pharmacist satisfaction and clinical needs for the real-time medication surveillance program in South Korea.

BACKGROUND: Since December 2010, a nationwide real-time medication surveillance program has been implemented in Korea to prevent potential adverse drug reactions. Our goal was to evaluate physicians' and pharmacists' satisfaction and clinical needs for the medication surveillance program in Korea. METHODS: Both web- and paper-based surveys were conducted using a structured questionnaire among 1164 physicians and pharmacists from May 23, 2014 to August 11, 2014. The survey consisted of questions about the participant's satisfaction with the medication surveillance program, clinical usefulness, clinical need for the medication surveillance program, and sociodemographic characteristics. Multivariate ordinal logistic regression was performed to investigate the factors influencing satisfaction levels with the medication surveillance program. RESULTS: We analyzed data from 1120 respondents, including 503 physicians and 617 pharmacists. Overall, 63.1% of the respondents were satisfied with the medication surveillance program. Pharmacists were more satisfied with the program than were physicians (69.1% vs. 55.6%; adjusted odds ratio, 2.13; 95% confidence interval, 1.65-2.76). Among the respondents, 77.8% cited a decrease in therapeutic duplication to be a major improvement resulting from the medication surveillance program, 82.6% considered the drug-drug interaction information useful, and 48.7% suggested that the program should include information on liver or kidney disease-drug interaction. CONCLUSIONS: Overall, 63.0% of physicians and pharmacists were satisfied, and a decrease in therapeutic duplication was regarded as the most beneficial component. Further improvements by considering clinical needs of physicians and pharmacists will be needed to increase satisfaction.

Regulatory effect of decreasing therapeutic duplication of respiratory drugs using a prescription database between 2012 and 2015.

Duplicative drug use increases the risk of adverse drug reactions and expends healthcare resources unnecessarily. No epidemiological evidence of the prevalence of therapeutic duplication (TD) involving respiratory system drugs exists. Therefore, we describe the prescription patterns of these drugs and estimate changes in TD rates following implementation of a new regulation in 2013. A time-series analysis using national healthcare data was conducted, involving eight classes, and patients prescribed any of these drugs between 2012 and 2015. We used two definitions of TD; duplicative prescriptions overlapped for more than 30 days by the same prescriber and for more than 1 day by different prescribers. We calculated relative and absolute difference in TD rates after the regulation. TD by the same prescriber decreased for respiratory drugs of six classes, but increased more than 10% for antihistamines (+10.28, +0.05). TD by a different prescriber decreased only for xanthine bronchodilators, but increased more than 10% for beta-receptor agonists (+27.07, +1.42), leukotriene receptor antagonists (+16.10, +0.44), cough suppressants (+15.64, +0.52), mucolytic agents (+11.16, +0.67). The 2013 regulation regarding respiratory drugs did not have the anticipated effect of reducing TD prevalence; more effective interventions are needed.

Effect of providing drug utilization review information on tricyclic antidepressant prescription in the elderly.

Tricyclic antidepressants are known as potentially inappropriate medications in the elderly. A notification issued in July 2015 in South Korea recommended caution while prescribing tricyclic antidepressants to the elderly. Further, since October 2015, the nationwide computerized drug utilization review monitoring system provides a pop-up window, on a real-time basis, whenever tricyclic antidepressants are prescribed to elderly outpatients. Therefore, we evaluated whether providing drug utilization review information was effective in reducing tricyclic antidepressant prescription to elderly outpatients. We used the Health Insurance Review and Assessment Service-Adult Patient Sample data from 2014 to 2016. Data related to the prescription of tricyclic antidepressants to outpatients aged 65 years or more were extracted. We determined the number of prescriptions per day per 100,000 elderly patients in each month, compared the average number of prescriptions before and after the drug utilization review information was provided, and evaluated the changes in the number of prescriptions by using an interrupted time series analysis. The average number of tricyclic antidepressant prescriptions per day per 100,000 elderly patients decreased from 76.6 (75.5 to 77.6) to 65.7 (64.5 to 66.9), a 14.2% reduction after the provision of drug utilization review information started. Following initiation of provision of drug utilization review information, there was an immediate drop of 9.2 tricyclic antidepressant prescriptions per day per 100,000 elderly patients, whereas there was no statistically significant change in trends. Providing the drug utilization review information on tricyclic antidepressant prescription for the elderly contributed to the reduction in tricyclic antidepressant prescriptions.

Mitochondrial Mutations in Cholestatic Liver Disease with Biliary Atresia.

Biliary atresia (BA) results in severe bile blockage and is caused by the absence of extrahepatic ducts. Even after successful hepatic portoenterostomy, a considerable number of patients are likely to show progressive deterioration in liver function. Recent studies show that mutations in protein-coding mitochondrial DNA (mtDNA) genes and/or mitochondrial genes in nuclear DNA (nDNA) are associated with hepatocellular dysfunction. This observation led us to investigate whether hepatic dysfunctions in BA is genetically associated with mtDNA mutations. We sequenced the mtDNA protein-coding genes in 14 liver specimens from 14 patients with BA and 5 liver specimens from 5 patients with choledochal cyst using next-generation sequencing. We found 34 common non-synonymous variations in mtDNA protein-coding genes in all patients examined. A systematic 3D structural analysis revealed the presence of several single nucleotide polymorphism-like mutations in critical regions of complexes I to V, that are involved in subunit assembly, proton-pumping activity, and/or supercomplex formation. The parameters of chronic hepatic injury and liver dysfunction in BA patients were also significantly correlated with the extent of hepatic failure, suggesting that the mtDNA mutations may aggravate hepatopathy. Therefore, mitochondrial mutations may underlie the pathological mechanisms associated with BA.

Factors associated with intention to be tested for HIV among men who have sex with men in a country with a very low HIV prevalence.

This study examined factors associated with the intention to take an HIV test among men who have sex with men (MSM) in South Korea. An internet website-based survey was conducted among users of the only and largest online MSM website between 20 July 2016, and 20 August 2016. A total of 2915 participants completed the survey and answered questions related to sociodemographic information, health behaviors, sexual behaviors, and HIV testing history. Of these, 2587 (88.7%) participants responded as having an intention to take an HIV test. A multivariable logistic regression analysis revealed the following as having reduced the intention to undergo HIV testing: very good subjective health status and no sexual interactions during the last 6 months (Adjusted odds ratios [AOR] 0.45 and 0.54, respectively). In contrast, increased intention to take an HIV test was associated with being 20-29 years old, 30-39 years old, not paying or receiving money for sex, having a history of HIV testing, and taking an HIV test once per 12 months (AOR 2.64, 2.13, 1.54, 1.81, and 2.17, respectively). In conclusion, HIV testing among MSM in this study was associated with age, subjective health status, sex(es) of one's sexual partner(s) during the last 6 months, sexual risk behaviors, HIV testing history, and undergoing regular HIV testing.

Prevalence and trends of pain associated with chronic diseases and personal out-of-pocket medical expenditures in Korea.

BACKGROUND: There have been few studies about pain using a big data. The purpose of this study was to identify the prevalence of pain, and trends of pain associated with chronic diseases and personal out-of-pocket medical expenditures over time. METHODS: Subjects were 58,151 individuals, using the Korea Health Panel from 2009 to 2013. Chi-square and multinomial logistic regression were conducted to identify the prevalence and odds ratios (ORs) of pain. Repeated measures ANOVA was used to find the trend over these 5 years. RESULTS: Prevalence of mild and severe pain was 28.1% and 1.7% respectively. The ORs of mild and severe pain were 1.6 and 1.4 in females compared with males. From 2009 to 2013, numbers of chronic diseases producing mild pain were 2.1, 2.4, 2.8, 2.9, and 3.1 and those producing severe pain were 3.0, 3.4, 3.9, 4.2, and 4.4, respectively. After applying the average South Korean inflation rate by year over 5 years, the annual, personal out-of-pocket medical expenditures (unit: ￦1,000) for mild pain were 322, 349, 379, 420, and 461, and those for severe pain were 331, 399, 504, 546, and 569, respectively (P < 0.0001). CONCLUSIONS: The pain prevalence was 29.8%. The numbers of chronic diseases and the personal out-of-pocket medical expenditures revealed increasing trends annually, especially in those with pain. Therefore, to eliminate and alleviate the pain, there needs to be further study for developing a systemic approach.

TM0416, a Hyperthermophilic Promiscuous Nonphosphorylated Sugar Isomerase, Catalyzes Various C5 and C6 Epimerization Reactions.

There is currently little information on nonphosphorylated sugar epimerases, which are of potential interest for producing rare sugars. We found a gene (the TM0416 gene) encoding a putative d-tagatose-3-epimerase-related protein from the hyperthermophilic bacterium Thermotoga maritima We overexpressed the TM0416 gene in Escherichia coli and purified the resulting recombinant protein for detailed characterization. Amino acid sequence alignment and a structural similarity search revealed that TM0416 is a putative nonphosphorylated sugar epimerase. The recombinant enzyme exhibited maximal C-3 epimerization of l-ribulose to l-xylulose at ∼80°C and pH 7 in the presence of 1 mM Mn2+ In addition, this enzyme showed unusually high activity for the epimerization of d-tagatose to d-sorbose, with a conversion yield of 20% after 6 h at 80°C. Remarkably, the enzyme catalyzed the isomerization of d-erythrose or d-threose to d-erythrulose significantly, with conversion yields of 71% and 54.5%, respectively, after 6 h at 80°C at pH 7. To further investigate the substrate specificity of TM0416, we determined its crystal structures in complex with divalent metal ions and l-erythrulose at resolutions of 1.5 and 1.6 Å. Detailed inspection of the structural features and biochemical data clearly demonstrated that this metalloenzyme, with a freely accessible substrate-binding site and neighboring hydrophobic residues, exhibits different and promiscuous substrate preferences, compared with its mesophilic counterparts. Therefore, this study suggests that TM0416 can be functionally classified as a novel type of l-ribulose 3-epimerase (R3E) with d-erythrose isomerase activity.IMPORTANCE Rare sugars, which occur naturally in small amounts, have attracted considerable attention in the food and drug industries. However, there is little information on nonphosphorylated sugar epimerases, which might potentially be applied for the production of rare sugars. This study describes the characterization and functional annotation of a putative nonphosphorylated sugar 3-epimerase from a hyperthermophilic bacterium. Furthermore, we determined its crystal structures in complex with divalent metal ions and l-erythrulose, highlighting its metal-dependent, bifunctional, sugar-isomerizing activity. This hyperthermophilic R3E exhibited d-erythrose/d-threose isomerase activity, with structural features near the substrate-binding site distinct from those of its mesophilic counterparts. Moreover, this metalloenzyme showed unusually high activity for the epimerization of d-tagatose to d-sorbose at 70°C. Therefore, TM0416 can be functionally classified as a novel type of promiscuous R3E with a potential for the production of rare sugars for the food and pharmaceutical industries.

The Association between Sleep Duration and Overweight in a School-Age Population in Seoul.

BACKGROUND: This study aimed to investigate the association between body mass index standard deviation scores and sleep duration in a school-age population in Seoul. METHODS: By using the secondary data of a sample survey (n=25,182) of the Student Health Examination in 2010, the proportions of those who were overweight (World Health Organization definition of body mass index >1.0 standard deviation score) were identified. The association of overweight with sleep duration was also explored after adjusting for age and for meat and vegetable intake, by using multiple logistic and linear regression analysis. RESULTS: Only 23.2% of participants slept 8 hours or more per day. The proportions of overweight participants were 34.2% of boys and 19.5% of girls. Significant odds ratios for overweight according to sleep duration (based on ≥8 sleeping hours) were 1.28 (for less than 6 hours), 1.31 (for 6-7 hours), and 1.28 (for 7-8 hours) in boys; and 1.19 (for 6-7 hours) and 1.17 (for 7-8 hours) in girls. Furthermore, significant regression coefficients for standard deviation scores (based on ≥8 sleeping hours) were 0.218 for less than 6 hours, 0.149 for 6-7 hours, and 0.099 for 7-8 hours in boys, and 0.137, 0.101, and 0.079 in girls, respectively. CONCLUSION: To prevent and manage overweight, it is necessary to develop a school health policy for ensuring optimal sleep duration in school-age population.

Agreement Between Actual and Perceived Body Weight in Adolescents and Their Weight Control Behaviors.

BACKGROUND: To investigate the agreements between actual and perceived body weight status among adolescents and to identify the associations of disagreements with their weight control behaviors. METHODS: This study used the secondary data of a sample survey (n=13,871) of the Seoul Student Health Examination among middle and high schools in 2010. Agreements between actual (underweight, normal, overweight, and obese, according to 2007 Korean National Growth Charts) and perceived body weight status (underweight, normal, overweight, and obese) were examined using Chi-square and Cohen's kappa agreement, and then multinomial logistic regression including gender, grade, and attempt of weight control or method of weight control was done. RESULTS: Agreements between actual and perceived body weight status were only 45.2%, and disagreements were up to 54.8%, including mild over- (20.4%), severe over- (1.8%), mild under- (29.5%), and severe under-estimation (3.1%). The kappa coefficient of agreement was only 0.19. The odds ratios on severe over-estimated perception were 1.59 (95% CI, 1.22-2.07) in female subjects, 1.78 (95% CI, 1.36-2.34) in diet control behaviors, and 1.53 (95% CI, 1.18-2.00) in exercise. The odds ratios on severe under-estimated perception were only 0.40 (95% CI, 0.32-0.50) in female subjects but 5.77 (95% CI, 3.68-9.06) in taking medication. CONCLUSION: There were associations of body weight control behaviors with disagreements of actual and perceived weight status. Therefore, further study is needed to identify the weight disagreement-related factors and to promote the desired weight control behaviors for adolescents.

Association of Meat Intake with Overweight and Obesity among School-aged Children and Adolescents.

BACKGROUND: This study aimed to investigate the association of overweight and obesity with red and white meat intake among children and adolescents using secondary survey data (n=16,261) from in-school Student Health Examination conducted in 2006 and 2007. METHODS: Descriptive statistics was conducted to investigate the frequency of meat intake per week. The body mass index (BMI) grades for obesity in boys and girls were classified using the standards from the 2007 Korean National Growth Charts. The association of meat intake with overweight and obesity was analyzed using Chi-square test and multiple logistic regression. RESULTS: The proportion of subjects with no intake/week vs. daily meat intake/week was 5.9% and 5.5%, respectively. No intake of meat was more frequent in those who were female and in middle school, whereas daily meat intake was more frequent in those who were male and in high school. The proportions of overweight and obesity in the no meat intake/week group and daily meat intake/week group were 12.3% and 11.1% vs. 8.1% and 9.9%, respectively. After adjusting for confounding variables, including age; consumption of instant noodles, soft drinks and fast foods, dairy products, and fruits and vegetables; and skipping breakfast, the odds ratios of overweight and obesity in the no meat intake/week group were 1.41 times higher (95% confidence interval, 1.04-1.85) than those in the daily meat intake/week group. CONCLUSION: It is important to consider correcting the perception about meat intake and obesity and avoid restricting meat intake to prevent overweight and obesity among children and adolescents.