• Journal of Korean Medical Science
• /
• v.33 no.44
• /
• pp.278.1-278.12
• /
• 2018

Background: We evaluated the association of blood pressure (BP) with blood levels of cadmium, lead, and cadmium and lead together (cadmium + lead) in a representative sample of adolescents from Korea. Methods: We used 2010-2016 data from the Korean National Health and Nutrition Examination Survey. This cross-sectional study enrolled adolescents aged at 10-18 years-old who completed a health examination survey and had blood measurements of lead and cadmium. The association of adjusted mean differences in diastolic and systolic BP with doubling of blood lead and cadmium were estimated by regression of BP against ${\log}_2$-transformed blood metals and their quartiles after covariate adjustment. Adjusted odds ratio for prehypertension were calculated for ${\log}_2$-transformed blood levels of lead and cadmium and their quartiles. Results: Our analysis of adolescents in Korea indicated that blood levels of lead and cadmium were not significantly associated with increased BP or risk of prehypertension. However, the cadmium + lead level was associated with prehypertension. Previous studies showed that blood levels of lead and cadmium were associated with increased BP and risk of hypertension in adult populations. We found no such association in Korean adolescents. Conclusion: We found that the cadmium + lead level was associated with prehypertension. The differences between adults and adolescents are because adolescents generally have lower levels of these blood metals or because adolescents only rarely have hypertension.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.38 no.4
• /
• pp.117-131
• /
• 2015

Conventional data envelopment analysis (DEA) models require that inputs and outputs are given as crisp values. Very often, however, some of inputs and outputs are given as imprecise data where they are only known to lie within bounded intervals. While a typical approach to addressing this situation for optimization models such as DEA is to conduct sensitivity analysis, it provides only a limited ex-post measure against the data imprecision. Robust optimization provides a more effective ex-ante measure where the data imprecision is directly incorporated into the model. This study aims to apply robust optimization approach to DEA models with imprecise data. Based upon a recently developed robust optimization framework which allows a flexible adjustment of the level of conservatism, we propose two robust optimization DEA model formulations with imprecise data; multiplier and envelopment models. We demonstrate that the two models consider different risks regarding imprecise efficiency scores, and that the existing DEA models with imprecise data are special cases of the proposed models. We show that the robust optimization for the multiplier DEA model considers the risk that estimated efficiency scores exceed true values, while the one for the envelopment DEA model deals with the risk that estimated efficiency scores fall short of true values. We also show that efficiency scores stratified in terms of probabilistic bounds of constraint violations can be obtained from the proposed models. We finally illustrate the proposed approach using a sample data set and show how the results can be used for ranking DMUs.

• Journal of the Korean Society of Food Culture
• /
• v.36 no.4
• /
• pp.401-411
• /
• 2021

Diet is important for muscle health and offers a protective effects against the loss of skeletal muscle mass and physical functions with advancing age. We analyzed the relationship between diet, metabolic disease risk, and sarcopenia in Korean female adults using the 2009-2011 Korea National Health and Nutrition Examination Survey (KNHANES). A total of 2038 adult women aged 50-64 years were classified into four groups based on the diagnosis of menopause and sarcopenia. The groups were the non-menopause and non-sarcopenia group (NMNS, n=249), the non-menopause and sarcopenia group (NMS, n=14), the menopause and non-sarcopenia group (MNS, n=1,653), and the menopause and sarcopenia group (MS, n=122). The socio-demographics, anthropometrics, blood profile, and dietary data of the subjects were collected. Those who were in both the sarcopenia groups were more obese (p<0.001), had greater waist circumferences (p<0.001), higher body mass index (p<0.001), and higher obesity rates (p<0.001) after adjustment for covariants. Both the sarcopenia groups also had higher plasma levels of total cholesterol (p<0.001), HbA1c (p=0.001), and vitamin D (p=0.020) than both the non-sarcopenia groups. Both the sarcopenia groups demonstrated a decreased intake of calcium (p=0.05), potassium (p=0.008), and niacin (p=0.008) than both the non-sarcopenia ones. Among the four groups, the NMS group showed the highest levels of total cholesterol, obesity, and lowest intake of micronutrients such as calcium, niacin, and potassium. Thus, muscle mass maintenance through weight control and adequate nutrient intake appears to demonstrate a potential association with preventing sarcopenia in Korean middle-aged women.

• Nutrition Research and Practice
• /
• v.13 no.2
• /
• pp.141-149
• /
• 2019

BACKGROUND/OBJECTIVES: This study examined the association between refined grain consumption by subtype and the incidence of hypertension from the Korean Genome and Epidemiology Study data. SUBJECTS/METHODS: In total, 5,018 participants (2,439 men and 2,579 women) from 40 to 69 years without hypertension were recruited at the beginning (2001-2002). Blood pressure and antihypertensive medication use were assessed biennially for the incidence of hypertension during the 8-year follow-up period (2009-2010). Hypertension was diagnosed as systolic blood pressure ${\geq}140mmHg$ or diastolic blood pressure ${\geq}90mmHg$ or antihypertensive medication use. Dietary intake including refined grains was assessed by a food frequency questionnaire at baseline and the follow-up (2005-2006). A multivariate Cox proportional hazard model was used to examine hazard ratios (HRs) and 95% confidence intervals (CIs) for incident hypertension according to refined-grain consumption. RESULTS: A total of 1,377 cases of hypertension (710 men and 667 women) were newly ascertained. Frequent noodle consumers (${\geq}5servings/week$) among the women had a 2.3-fold higher risk of hypertension than infrequent noodle consumers after adjustment for potential confounders (HR = 2.31, 95% CI = 1.33-4.01, P for trend = 0.0001). However, no significant association was found among the men. The intake of other refined grain products such as white rice and breads was not associated with the incidence of hypertension. CONCLUSION: Frequent noodle consumption was positively associated with a risk of incident hypertension in South Korean women.

• The Korean Journal of Food And Nutrition
• /
• v.32 no.1
• /
• pp.69-78
• /
• 2019

We investigated coffee consumption in relation to the abdominal obesity as defined by waist circumference in Korean women aged 19~64 years, using data from the National Health and Nutrition Examination Survey 2012~2016. The participants to the study were classified according to 3-in-1 coffee consumption level (none-coffee, ${\leq}1$ time/day of 3-in-1 coffee, >1 time/day of 3-in-1 coffee) by a food frequency questionnaire. The analysis was conducted by the following age groups: <50 years and $50{\leq}$ years. The 3-in-1 coffee consumption group had significantly more smokers and more alcohol consumption frequency as compared to the none-coffee group. The energy intake from the participants in the 3-in-1 coffee consumption of ${\leq}1$ time/day of 3-in-1 coffee group, and >1 time/day of 3-in-1 coffee group were 131.2 kcal/day and 123.1 kcal/day. In the 50 years or over age group, >1 time/day of 3-in-1 coffee group was at a lower risk of abdominal obesity as defined by waist circumference, compared with the non-coffee group multivariable adjustment (OR: 0.44, 95% CI: 0.25~0.77). Our findings suggest that the 3-in-1 coffee consumption may be related to abdominal obesity as defined by waist circumference in Korean females aged 50 years or over.

• Nutrition Research and Practice
• /
• v.15 no.3
• /
• pp.329-345
• /
• 2021

BACKGROUD/OBJECTIVES: Evidence has suggested an association between serum vitamin D and metabolic syndrome (MetS), but prospective studies are very limited. The objective was to assess the dose-response association between serum vitamin D concentration and MetS risk using a systematic review and meta-analysis of updated observational studies. MATERIALS/METHODS: Using MEDLINE, PubMed, and Embase, a systematic literature search was conducted through February 2020 and the references of relevant articles were reviewed. A random-effects model was used to estimate the summary odds ratio/relative risk and 95% confidence interval (CI). Heterogeneity among studies was evaluated with I² statistic. In total, 23 observational studies (19 cross-sectional studies, and four cohort studies) were included in the meta-analysis. RESULTS: The pooled estimates (95% CI) for MetS per 25-nmol/L increment in serum vitamin D concentration were 0.80 (95% CI, 0.76-0.84; I² = 53.5) in cross-sectional studies, and 0.85 (95% CI, 0.72-0.98; I² = 85.8) in cohort studies. Similar results were observed, irrespectively of age of study population, study location, MetS criteria, and adjustment factors. There was no publication bias for the dose-response meta-analysis of serum vitamin D concentrations and MetS. CONCLUSIONS: Dose-response meta-analysis demonstrated that a 25-nmol/L increment in the serum vitamin D concentration was associated with 20% and 15% lower risks of MetS in cross-sectional studies and cohort studies, respectively.

• Journal of Digital Convergence
• /
• v.11 no.5
• /
• pp.371-384
• /
• 2013

The purpose of this study was to develop the risk-adjusted mortality model using Korean Hospital Discharge Injury data and US National Hospital Discharge Survey data and to suggest some ways to manage hospital mortality rates through comparison of Korea and United States Hospital Standardized Mortality Ratios(HSMR). This study used data mining techniques, decision tree and logistic regression, for developing Korea and United States risk-adjustment model of in-hospital mortality. By comparing Hospital Standardized Mortality Ratio(HSMR) with standardized variables, analysis shows the concrete differences between the two countries. While Korean Hospital Standardized Mortality Ratio(HSMR) is increasing every year(101.0 in 2006, 101.3 in 2007, 103.3 in 2008), HSMR appeared to be reduced in the United States(102.3 in 2006, 100.7 in 2007, 95.9 in 2008). Korean Hospital Standardized Mortality Ratios(HSMR) by hospital beds were higher than that of the United States. A two-aspect approach to management of hospital mortality rates is suggested; national and hospital levels. The government is to release Hospital Standardized Mortality Ratio(HSMR) of large hospitals and to offer consulting on effective hospital mortality management to small and medium hospitals.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.17 no.1
• /
• pp.3-9
• /
• 2006

Objectives: Obesity is one of risk factors for psychological and social adjustment problems (depression, low self esteem, low school function etc). Quality of life(QOL) is comprehensive and multidimensional construct including physical, emotional, social and school functioning. Some authors reported that child and adolescent obesity is associated with impaired QOL. This study was to examine the association between QOL and body mass index (BMI) in middle school students. Methods : Cross sectional analysis of 471 adolescents between the ages of 13 and 14 years ($mean{\pm}SD,\;13.4{\pm}0.6$), who attended one of middle schools in Seoul, Korea. Participants' QOL were scored by using Korean version of pediatric QOL inventory generic score scale ($PedsQL^{TM}$ 4.0). Participants had a $mean{\pm}SD\;BMI\;of\;21.3{\pm}4.0$. Self reports and parent proxy reports using $PedsQL^{TM}$ 4.0 were administered to measure participant's QOL. Participants were divided into four groups by BMI (Male: obesity group >26.5, at risk group 23.2-26.5, normal weight group 15.8-23.1, underweight group <15.8, Female : obesity group >25.2, at risk group 22.9-25.2, normal weight group 16.0-22.8, underweight group <16.0). Results : Compared with other groups, obese adolescents reported significantly(p<0.01) love. QOL in all domains. Obese adolescents were more likely to have impaired QOL than normal weight adolescents (Odds Ratio, 8.3, 95% confidence interval, 4.0-16.7). Conclusion : Obese adolescents have lower QOL than normal weight adolescents. Psychiatrist, parents, and teachers need to be informed of the risk fur impaired QOL in obese adolescents to target interventions that could enhance health outcomes.

• Journal of Preventive Medicine and Public Health
• /
• v.34 no.1
• /
• pp.9-20
• /
• 2001

Objectives : To explore the relationship between Percutaneous Transluminal Coronary Angioplasty(PTCA) volume and the associated immediate outcome. Methods : A total of 1,379 PTCAs were peformed in 25 hospitals in Korea between October 8 and December 31 in 1997. Data from 1,317 PTCAs (95.5%) were collected through medical record abstraction. Inter-observer reliability of the data was examined using the Kappa statistic on a subsample of 110 PTCA procedures from five hospitals. Intra-observer reliability of the data was also examined. PTCA success and immediate adverse outcomes were selected as the outcome variables. A successful PTCA was defined as a case that shows less than 50% diameter stenosis and more than 20% reduction of diameter stenosis. Immediate adverse outcomes included deaths during the same hospitalization, emergency coronary artery bypass graft (CABG) within 24 hours after PTCA, and acute myocardial infarction within 24 hours after PTCA. The numbers of PTCAs performed in 1997 per hospital were used as the volume variables. Results : Without adjusting for patient risk factors that may affect outcomes, procedures at high volume hospitals ($\geq200$ cases per year) had a greater success rate (P=0.001) than low volume hospitals. There was a marginally significant difference (P=0.070) in major adverse outcome rates between high and low volume hospitals. After adjusting for risk factors, there were significant differences in procedural failure and major adverse outcome rates between high and low volume hospitals. Conclusions : After adjusting for patient clinical risk factors, the hospital volume of PTCA was associated with immediate outcomes. It is recommended that a PTCA volume per year be established in order to improve the immediate outcome of this procedure in Korea.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.1
• /
• pp.340-348
• /
• 2016

This study, through a review of advanced research, first, examined the attitudes to products traded in import agency shopping malls and the characteristic variables(product characteristic, customer characteristic) that influence the purchasing intention to understand influencing relationship. Second, the role of adjustment in the relationship between the attitude to the products and the purchasing intention was examined by putting the perceived risk to the moderating variables. Third, efficient controllable basic data in the characteristic variables capable of influencing the management of and import agency shopping mall based on the implications was obtained from the above research result. The 126 responses collected from a questionnaire were analyzed using the SPSS 23.0 statistics package, and the analysis result can be summarized as follows. First, the main cause that influences the attitude of treated products in an import agency shopping mall is the country of origin, national image, innovativeness and price perception, not the brand image. Second, the attitude of the products influences the purchasing intention of the import agency shopping mall. Third, the perceived risk partially plays a role as a moderating variable in the relationship between the attitude of products and the purchasing intention.