• Korea journal of population studies
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• v.32 no.1
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• pp.1-23
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• 2009

This paper uses a survey data to analyze the age-specific fertility rates, age-specific cumulative fertility rates, and ages of marriage of the five birth cohorts of Korean women born in the 1940s and thereafter. It was found that later cohorts reach their highest age-specific fertility rate at higher ages than earlier cohorts. The age-specific cumulative fertility rates of the 1950s and 1960 cohorts were found to be much lower than those of the immediately preceding cohorts, while those of the 1970s and 1980s cohorts were not different from those of the 1960s cohorts. Women belonging to later cohorts were found to get married at relatively higher ages. The estimation results of the hazard model show that women belonging to later cohorts and those with more schooling have a tendency to get married at higher ages. The effect of the birth cohorts is thought to be due to the economic, social, and cultural changes in Korea during the late 50 years or so. The time interval between a woman‘s marriage and first birth was found not to be affected by either the year of marriage or that of her birth. Also, those who remained employed for some time around their marriage and those with low schooling were found to have a lower first child birth hazard, which implies that married women’s employment status and family income play an important role in their decisions on childbirth.

• Journal of Nutrition and Health
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• v.51 no.1
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• pp.40-49
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• 2018

Purpose: The number of patients with dyslipidemia have been increasing steadily over the past few decades in South Korea. The association between the chromium level and chronic disease has attracted considerable interest, but few studies have been conducted on the Korean population. The aim of this study was to identify the dietary and non-dietary correlates of the toenail chromium level, and evaluate the association between the toenail chromium level and dyslipidemia. Methods: The baseline data of an ongoing prospective cohort study in Yeungnam area in South Korea were analyzed. A total of 500 participants aged 35 years or older who completed questionnaires on their demographics, lifestyle characteristics, and medical information were included. The toenail chromium level was analyzed by neutron activation analysis. The dietary intake was assessed using a validated 146-item semi-quantitative food frequency questionnaire. The blood lipid profiles were obtained from medical examinations conducted by the Korean National Health Insurance Service or medical institutions. Results: Higher chromium levels were associated with the residential area (urban), higher education level, higher intakes of noodles and vegetables, and lower intake of fruits. Multiple logistic regression analysis showed that the toenail chromium levels were not associated significantly with the prevalence of dyslipidemia (odds ratio: 0.99, 95% confidence interval: 0.61 ~ 1.60). Conclusion: This study is the first study in Korea to determine the independent correlates of the toenail chromium levels and the association between chromium exposure and dyslipidemia. These findings provide useful scientific evidence for the development of chromium intake guidelines for the Korean population.

• Journal of Environmental Health Sciences
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• v.47 no.5
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• pp.486-495
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• 2021

Background: Particulate matter (PM) is one of the leading causes of premature death worldwide. Previous studies in South Korea have applied a relative risk calculated from Western populations when estimating the disease burden attributable to PM. However, the relative risk of PM on health outcomes may not be the same across different countries or regions. Objectives: This study aimed to estimate the premature deaths and socioeconomic costs attributable to long-term exposure to PM in South Korea. We considered not only the difference in PM concentration between regions, but also the difference in relative risk. Methods: National monitoring data of PM concentrations was obtained, and missing values were imputed using the AERMOD model and linear regression model. As a surrogate for relative risk, hazard ratios (HRs) of PM for cardiovascular and respiratory mortality were estimated using the National Health Insurance Service-National Sample Cohort. The nation was divided into five areas (metropolitan, central, southern, south-eastern, and Gangwon-do Province regions). The number of PM attributable deaths in 2018 was calculated at the district level. The socioeconomic cost was derived by multiplying the number of deaths and the statistical value of life. Results: The average PM₁₀ concentration for 2014~2018 was 45.2 ㎍/m³. The association between long-term exposure to PM₁₀ and mortality was heterogeneous between areas. When applying area-specific HRs, 23,811 premature deaths from cardiovascular and respiratory disease in 2018 were attributable to PM₁₀ (reference level 20 ㎍/m³). The corresponding socioeconomic cost was about 31 trillion won. These estimated values were higher than that when applying nationwide HRs. Conclusions: This study is the first research to estimate the premature mortality caused by long-term exposure to PM using relative risks derived from the national population. This study will help precisely identify the national and regional health burden attributed to PM and establish the priorities of air quality policy.

• Journal of Chest Surgery
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• v.54 no.5
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• pp.369-376
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• 2021

Background: Sutureless and rapid deployment valves for aortic valve replacement (AVR) were introduced in Korea in December 2016. This study evaluated changing trends in the prosthetic valves used for AVR in Korea after the introduction of sutureless and rapid deployment valves. Methods: From December 2016 to December 2018, 4,899 patients underwent AVR in Korea. After applying the exclusion criteria, 4,872 patients were analyzed to determine changes in the type of prosthetic valve used for AVR. The study period was divided into 5 groups corresponding to 5-month intervals. Results: The total number of AVR cases was 194.88±28.78 per month during the study period. Mechanical valves were used in approximately 27% to 33% of cases, and the proportion of mechanical valve use showed a tendency to decrease, with marginal significance overall (p=0.078) and significant decreases in patients less than 60 years of age and in men (p=0.013 and p=0.023, respectively). The use of sutureless valves increased from 13.4% to 25.8% of cases (p<0.001), especially in elderly patients (>70 years) and those requiring concomitant surgery. In a comparison between sutureless and rapid deployment valves, the use of Perceval S valves (a type of sutureless valve), gradually increased (p<0.001). Conclusion: After the introduction of sutureless and rapid deployment valves in Korea, the rate of use of these new valves remarkably increased, especially in elderly patients and those requiring concomitant surgery. Further studies should investigate the clinical outcomes of these new prostheses.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.231-242
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• 2019

The aim of this study was the relationship between smoking, alcohol drinking and vitamin D level among Korean adults using data from the '6th(2013-2014) Korean National Health and Nutrition Examination Survey'. The data used in this study were analyzed for 3,565 people who were over the age of 19 ages and checked vitamin D level and consumption frequencies of vitamin D rich foods among 15,568 respondents to the '6th(2013-2014) Korean National Health and Nutrition Examination Survey'. The subjects were divided into four groups: None group(non-smoking and non-alcohol drinking), smoking only group, alcohol drinking only group and both group (smoking and alcohol drinking). The mean serum vitamin D level of the subjects was $16.5{\pm}0.20ng/mL$ and 73.5% of vitamin D levels were insufficient and deficiency. The results from hierarchical multiple logistic regression showed that the Odds ratio for insufficient vitamin D due to smoking and alcohol drinking were significantly higher in the smoking only group 2.281(95% CI 1.080-4.817)times and both group 1.356(95% CI 1.010-1.922)times than none group. Our results showed the relationship between smoking, alcohol drinking and vitamin D level was significant in Korean adults. Future studies, such as a more systematic cohort study investigating the relationship between smoking, alcohol drinking and vitamin D level may be helpful in confirming the causal relationship between smoking, alcohol drinking and vitamin D level.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.1
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• pp.57-63
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• 2019

Hypertension is caused by a combination of genetic and environmental factors. In advanced countries, more than 30% of adults have hypertension. Among the genetic factors affecting hypertension, there are reports from European cohort studies that variants of the MACROD2 gene are correlated with blood pressure and the hypertension status. In this study, genetic polymorphisms of the MACROD2 gene region were selected and extracted based on Korean Genome and Epidemiology data, and logistic regression analysis was then performed for the hypertensive state. Linear regression analysis was also performed for the systolic and diastolic blood pressure. As a result, 16 SNPs showed a statistically significant association with a hypertensive state, and 2 SNPs (rs16996211, rs6034240) showed statistical significance, even in blood pressure. The most significant rs16996211 had a relative risk of hypertension of 0.85 (CI: 0.76~0.95, $P=3.1{\times}10^{-3}$), as well as an association with the systolic blood pressure (beta=-0.75, P=0.024) and diastolic blood pressure (beta=-0.59, P=0.01). These results suggest that polymorphisms of the MACROD2 gene are associated with hypertension in both Caucasians and Koreans, and highlight the potential genetic correlations with the pathogenesis of hypertension.

• Journal of Nutrition and Health
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• v.52 no.5
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• pp.465-474
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• 2019

Purpose: This study examined the association between the serum 25-hydroxyvitamin D concentration and the cognitive functions in Korean elderly. Methods: The subjects were 393 adults aged 60 years or older who participated in the Yangpyeong cohort between July 2009 and August 2010. The subjects were classified into deficiency, insufficiency, or adequacy groups according to the serum 25-hydroxyvitamin D concentration diagnostic criteria suggested by the US Institute of Medicine (IOM). The cognitive function was assessed based on the Korean version of the Mini-Mental State Examination (MMSE-KC). The dietary intake was assessed using the quantitative food frequency questionnaire with 106 food items. Results: The proportions of deficiency, insufficiency, or adequacy in serum 25-hydroxyvitamin D were 6.6%, 44.5%, and 48.9%, respectively. The serum 25-hydroxyvitamin D concentration was significantly higher in men than in women and in outdoor workers than in other occupations. The adequacy group had higher MMSE-KC scores than the other two groups, but not to a significant degree. The proportion of cognitive impairment tended to decrease with increasing serum vitamin D concentration to deficiency, insufficiency, and adequacy (p for trend = 0.029). The deficiency group had a 2.28 times higher risk of cognitive impairment than the adequacy group, but the difference was not statistically significant (OR, 2.28; 95% CI, 0.18 ~ 1.07, p for trend = 0.119). Conclusion: The serum vitamin D concentration tended to be associated with the cognitive function in elderly Koreans living in rural areas. To confirm the associations, further longitudinal studies with large samples were required.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.36-44
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• 2019

Swallowing impairment is a frequent complication following stroke. The characteristics of swallowing impairment with stork patient can facilitate identification of individuals at risk of dysphagia would be of great helpful. The present study examined oropharyngeal swallowing impairment with subacute stroke patients using the Modified Barium Swallowing Impairment Profile(MBSImP). The 49 consecutive patients with the supratentorial stroke met inclusion criteria for the present study. A retrospective review was performed of patients who underwent the videofluoroscopic swallowing study(VFSS). Of Stroke patients, 95.9% exhibited abnormal function of lip closure. 98% and 57.1 % shown abnormal tongue function and lingual motion, respectively. Oral residue was present in 51% and delayed pharyngeal response was present in 89.9%. In addition, abnormal laryngeal and hyoid excursion was seen in 42.9% and 87.8%, respectively. Abnormal function of soft palate elevation was present in 18.4% and abnormal epiglottic movement was seen in 4.1%. 30.6% of 30.6% of these patients exhibited abnormal laryngeal closure. All of the stroke patients(100%) in this study exhibited abnormal pharyngeal stripping wave and pharyngoesophageal segment opening. Abnormal tongue base retraction and oral reside were present 91.8%, respectively. The results suggest that stroke patient is more likely to exhibit reduced swallowing functions including lip closure, tongue control, initiation of pharyngeal swallow, anterior hyoid motion, tongue base retraction, pharyngeal residue and pharyngoesophageal contraction. Therefore, these data could provide valid and precise information regarding physiological evidence to delineate symptoms of dysphagia in this stroke cohort. Future studies should explore the bolus effect in the swallowing impairment.

• Korean Journal of Community Nutrition
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• v.26 no.4
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• pp.280-295
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• 2021

Objectives: This study aimed to examine the characteristics of patients according to their nutritional status as assessed by five nutritional screening tools: Patient-Generated Subjective Global Assessment (PG-SGA), NUTRISCORE, Nutritional Risk Index (NRI), Prognostic Nutritional Index (PNI), and Controlling Nutritional Status (CONUT) and to compare the agreement, sensitivity, and specificity of these tools. Methods: A total of 952 gastric cancer patients who underwent gastrectomy and chemotherapy from January 2009 to December 2012 at the Samsung Medical Center were included. We categorized patients into malnourished and normal according to the five nutritional screening tools 1 month after surgery and compared their characteristics. We also calculated the Spearman partial correlation, Cohen's Kappa coefficient, the area under the curve (AUC), sensitivity, and specificity of each pair of screening tools. Results: We observed 86.24% malnutrition based on the PG-SGA and 85.82% based on the NUTRISCORE among gastric cancer patients in our study. When we applied NRI or CONUT, however, the malnutrition levels were less than 30%. Patients with malnutrition as assessed by the PG-SGA, NUTRISCORE, or NRI had lower intakes of energy and protein compared to normal patients. When NRI, PNI, or CONUT were used to identify malnutrition, lower levels of albumin, hemoglobin, total lymphocyte count, total cholesterol, and longer postoperative hospital stays were observed among patients with malnutrition compared to those without malnutrition. We found relatively high agreement between PG-SGA and NUTRISCORE; sensitivity was 90.86% and AUC was 0.78. When we compared NRI and PNI, sensitivity was 99.64% and AUC was 0.97. AUC ranged from 0.50 to 0.67 for comparisons between CONUT and each of the other nutritional screening tools. Conclusions: Our study suggests that PG-SGA and NRI have a relatively high agreement with the NUTRISCORE and PNI, respectively. Further cohort studies are needed to examine whether the nutritional status assessed by PG-SGA, NUTRISCORE, NRI, PNI, and CONUT predicts the gastric cancer prognosis.

• Korean Journal of Community Nutrition
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• v.27 no.3
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• pp.205-222
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• 2022

Objectives: This study examined the characteristics of patients according to nutritional status assessed by five nutritional screening tools: Patient-Generated Subjective Global Assessment (PG-SGA), NUTRISCORE, Nutritional Risk Index (NRI), Prognostic Nutritional Index (PNI), and Controlling Nutritional Status (CONUT) and to compare the agreement, sensitivity, and specificity of these tools. Methods: A total of 952 gastric cancer patients who underwent gastrectomy and chemotherapy from January 2009 to December 2012 were included. The patients were categorized into malnutrition and normal status according to five nutritional screening tools one month after surgery. The Spearman partial correlation, Cohen's Kappa coefficient, the area under the curve (AUC), sensitivity, and specificity of each two screening tools were calculated. Results: Malnutrition was observed in 86.24% of patients based on the PG-SGA and 85.82% based on the NUTRISCORE. When NRI or CONUT were applied, the proportions of malnutrition were < 30%. Patients with malnutrition had lower intakes of energy and protein than normal patients when assessed using the PG-SGA, NUTRISCORE, or NRI. Lower levels of albumin, hemoglobin, total lymphocyte count, and total cholesterol and longer postoperative hospital stays were observed among patients with malnutrition compared to normal patients when NRI, PNI, or CONUT were applied. Relatively high agreement for NUTRISCORE relative to PG-SGA was found; the sensitivity was 90.86%, and the AUC was 0.78. When NRI, PNI, and CONUT were compared, the sensitivities were 23.72% for PNI relative to NRI, 44.53% for CONUT relative to NRI, and 90.91% for CONUT relative to PNI. The AUCs were 0.95 for NRI relative to PNI and 0.91 for CONUT relative to PNI. Conclusions: NUTRISCORE had a high sensitivity compared to PG-SGA, and CONUT had a high sensitivity compared to PNI. NRI had a high specificity compared to PNI. This relatively high sensitivity and specificity resulted in 77.00% agreement between PNI and CONUT and 77.94% agreement between NRI and PNI. Further cohort studies will be needed to determine if the nutritional status assessed by PG-SGA, NUTRISCORE, NRI, PNI, and CONUT predicts the gastric cancer prognosis.