• 응용통계연구
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• 제29권3호
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• pp.549-557
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• 2016

장기간의 기후 자료가 누적되다 보면 자료의 수집과정에서 시스템적 오류나 측정 장비의 고장 등으로 인하여 연속적 결측이 종종 발생하게 된다. 연속적인 결측 형태를 갖는 경우 시계열 결측 자료를 대체하는 것에 어려움이 따른다. 이러한 경우 참조시계열을 이용하여 결측값을 대체할 수 있다. 참조시계열은 결측이 발생한 시계열과 관련성이 높은 주변지점의 시계열로 구성할 수 있다. 본 연구에서는 결측값을 대체시킬 수 있는 3가지 결측복원 기법-수정된 정규화비율 방법, 회귀 방법, IDW 방법-을 비교하는 시뮬레이션을 수행하였다. 우리나라 14개 지점의 기후관측소의 일평균기온값을 대상으로 비교한 결과 남쪽 해안가에 위치한 기후관측소의 자료에 대해서는 IDW 방법이 가장 정확한 것으로 나타났으며, 그 외 지역의 기후관측소 자료에 대해서는 회귀 방법이 가장 정확한 것으로 나타났다.

• Clinical and Experimental Pediatrics
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• 제59권7호
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• pp.298-302
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• 2016

Purpose: Recent reports showed that plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) could be a useful biomarker of intravenous immunoglobulin (IVIG) unresponsiveness and coronary artery lesion (CAL) development in Kawasaki disease (KD). The levels of these peptides are critically influenced by age; hence, the normal range and upper limits for infants and children are different. We performed an age-adjusted analysis of plasma NT-proBNP level to validate its clinical use in the diagnosis of KD. Methods: The data of 131 patients with KD were retrospectively analyzed. The patients were divided into 2 groups-group I (high NT-proBNP group) and group II (normal NT-proBNP group)-comprising patients with NT-proBNP concentrations higher and lower than the 95th percentile of the reference value, respectively. We compared the laboratory data, responsiveness to IVIG, and the risk of CAL in both groups. Results: Group I showed significantly higher white blood cell count, absolute neutrophil count, C-reactive protein level, aspartate aminotransferase level, and troponin-I level than group II (P<0.05). The risk of CAL was also significantly higher in group I (odds ratio, 5.78; P=0.012). IVIG unresponsiveness in group I was three times that in group II (odds ratio, 3.35; P= 0.005). Conclusion: Age-adjusted analysis of plasma NT-proBNP level could be helpful in predicting IVIG unresponsiveness and risk of CAL development in patients with KD.

• Korean Circulation Journal
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• 제53권12호
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• pp.843-854
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• 2023

Background and Objectives: We evaluated the effect of diabetes on the relationship between body mass index (BMI) and clinical outcomes in patients following percutaneous coronary intervention (PCI) with drug-eluting stent implantation. Methods: A total of 6,688 patients who underwent PCI were selected from five different registries led by Korean Multicenter Angioplasty Team. They were categorized according to their BMI into the following groups: underweight (<18.5 kg/m²), normal weight (18.5-24.9 kg/m²), overweight to obese (≥25.0 kg/m²). Major adverse cardiac and cerebrovascular events (MACCE), defined as a composite of death, nonfatal myocardial infarction, stroke, and target-vessel revascularization, were compared according to the BMI categories (underweight, normal and overweight to obese group) and diabetic status. All subjects completed 1-year follow-up. Results: Among the 6,688 patients, 2,561 (38%) had diabetes. The underweight group compared to normal weight group had higher 1-year MACCE rate in both non-diabetic (adjusted hazard ratio [HR], 2.24; 95% confidence interval [CI], 1.04-4.84; p=0.039) and diabetic patients (adjusted HR, 2.86; 95% CI, 1.61-5.07; p<0.001). The overweight to obese group had a lower MACCE rate than the normal weight group in diabetic patients (adjusted HR, 0.67 [0.49-0.93]) but not in non-diabetic patients (adjusted HR, 1.06 [0.77-1.46]), with a significant interaction (p-interaction=0.025). Conclusions: Between the underweight and normal weight groups, the association between the BMI and clinical outcomes was consistent regardless of the presence of diabetes. However, better outcomes in overweight to obese over normal weight were observed only in diabetic patients. These results suggest that the association between BMI and clinical outcomes may differ according to the diabetic status.

• Journal of Preventive Medicine and Public Health
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• 제32권4호
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• pp.513-525
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• 1999

Objectives : High-normal blood pressure' is a factor influencing decision to initiate targeted intensive intervention strategy in westernized populations. JNC-VI offered the vigorous lifestyle modification for persons with 'high-normal blood pressure', who could be early detected. As a hypertension seems to be the result of multiple genetic factors operating in concert with associated environmental factors, it will be necessary to identify the high-normal blood pressure as a risk factor of hypertension for applying primary prevention strategy in Korean people. Methods : Although cohort study design might be adequate to recruit incidence cases, to keep time sequence of events, and to prevent information bias, nested case-control study was chosen for avoiding measurement errors because hypertension is a benign disease. Source population was the 'Seoul Cohort' participants and follow-up was done by using Korea Medical Insurance Corporation's database on the utilization of health services from 1 Jan93 to 30Jun97. Incidence cases were ascertained through the chart review, telephone contacts, and direct blood pressure measurements. Controls included the pairing of 4 individuals to each case on the basis of age. Results : As 75% of 247 incident cases had high-normal blood pressure, the crude odds ratio for hypertension was 2.04 (95% CI 1.47-2.83). Another statistically significant risk factors of hypertension were body mass index, dietary fiber, alcohol consumption, weekly activity and history of quitting smoking. The multivariate odds ratio of high-normal blood pressure adjusted for all risk factors was 1.84 (95% CI 1.31-2.56). Among high-normal blood pressure group, body mass index, weekly ethanol amounts, weekly physical activity, and dietary fiber except history of quitting smoking were still risk factors of hypertension. Conclusion : 'High-normal blood pressure' is a risk factor for hypertension in Korean middle-aged men, which represents that the vigorous lifestyle modification for persons with 'high-normal blood pressure' is need.

• Neonatal Medicine
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• 제25권3호
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• pp.118-125
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• 2018

Purpose: The pre-pregnancy body mass index (BMI) is associated with adverse neonatal outcomes. However, studies on very low birth weight (VLBW) infants are rare. This study aimed to investigate the effect of maternal pre-pregnancy BMI on VLBW infants. Methods: This retrospective study evaluated singleton VLBW infants born at the CHA Gangnam Medical Center from 2006 to 2016. The neonates were classified into three groups according to the maternal pre-pregnancy BMI: underweight (<$18.5kg/m^2$), normal weight (${\geq}18.5$ to <$23kg/m^2$), and overweight or obese (${\geq}23kg/m^2$). Clinical characteristics and morbidities of mothers and infants were analyzed. Results: A total of 181 infants belonging to underweight (16.6%), normal weight (58.6%), and overweight or obese (24.8%) groups were enrolled. The pre-pregnancy BMI had a significant negative correlation with gestational age (r=-0.198, P=0.001) and a significant positive correlation with the z-score of the birth weight (r=0.078, P=0.001) and body length (r=0.067, P=0.008). The number of extremely preterm infants was significantly higher in the overweight or obese group. The proportion of risk of small for gestational age infants was higher in the underweight group (adjusted odds ratio [OR], 2.958; 95% confidence interval [CI], 1.113 to 7.864), whereas that of infants with severe retinopathy of prematurity was higher in the overweight or obese group (adjusted OR, 9.546; 95% CI, 1.230 to 74.109). Conclusion: In our population of VLBW infants, the pre-pregnancy BMI was associated with gestational age, intrauterine growth, and adverse neonatal outcomes. Therefore, proper weight control before pregnancy is important.

• 지역사회간호학회지
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• 제28권4호
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• pp.359-365
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• 2017

Purpose: This study aims to investigate gender differences in the association between depressive symptoms and weight, weight perception, and body satisfaction among Korean adolescents. Methods: A secondary data analysis was performed on data from 33,374 adolescents who participated in the 2015 Adolescent Health Behavior Online Survey. They were classified as underweight, normal weight, or overweight/obese; weight perception was classified into perception of being underweight, normal weight, or overweight/obese; and weight satisfaction into desire to gain weight, satisfied, and desire to lose weight. Results: Among boys, perception of being underweight (adjusted odds ratio [AOR]: 1.20, 95% confidence interval [CI]: 1.07~1.35) and desire to gain weight (AOR: 1.45, 95% CI: 1.30~1.62) were associated with depression. Among girls, perception of being overweight or obese (AOR: 1.18, 95% CI: 1.07~1.29) and a desire to lose weight (AOR: 1.30, 95% CI: 1.18~1.42) were associated with depression. Conclusion: Gender differences were observed in the association between weight perception and depression in adolescents. The perception of being underweight among boys and the perception of being overweight/overweight among girls were associated with depression. Thus, gender-specific intervention programs to correct weight perception and weight satisfaction are needed in order to relieve depressive symptoms in adolescents.

• Korean Journal of Radiology
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• 제20권6호
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• pp.976-984
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• 2019

Objective: To establish diagnostic criteria for pulmonary arterial hypertension (PAH) in children by using parameters obtained through noninvasive cardiac computed tomography (CCT). Materials and Methods: We retrospectively measured parameters from CCT images of children from a single institution in a multiple stepwise process. A total of 208 children with mean age of 10.5 years (range: 4 days-18.9 years) were assessed. The variables were classified into three groups: the great arteries; the ventricular walls; and the bilateral ventricular cavities. The relationship between the parameters obtained from the CCT images and mean pulmonary arterial pressure (mPAP) was tested and adjusted by the children's body size. Reference curves for the pulmonary trunk diameter (PTD) and ratio of diameter of pulmonary trunk to ascending aorta (rPTAo) of children with CCT images of normal hearts, adjusted for height, were plotted. Threshold lines were established on the reference curves. Results: PTD and rPTAo on the CCT images were significantly positively correlated with mPAP (r > 0.85, p < 0.01). Height was the body size parameter most correlated with PTD (r = 0.91, p < 0.01) and rPTAo (r = -0.69, p < 0.01). On the basis of the threshold lines on the reference curves, PTD and rPTAo both showed 88.9% sensitivity for PAH diagnosis, with negative predictive values of 93.3% and 92.9%, respectively. Conclusion: PTD and rPTAo measured from CCT images were significantly correlated with mPAP in children. Reference curves and the formula of PTD and rPTAo adjusted for height could be practical for diagnosing PAH in children.

• Asian Pacific Journal of Cancer Prevention
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• 제13권7호
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• pp.3271-3274
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• 2012

Purpose : This study was performed to assess whether the weight status is associated with screening rates of breast and cervical cancer in Korean women. Methods: Study participants included women aged between 30 and 80 years from the 4th Korea National Health and Nutrition Examination Survey from 2007 to 2009. Body mass index was classified into ${\sim}18.4kg/m^2$ (underweight), $18.5{\sim}22.9kg/m^2$ (normal), $23{\sim}24.9kg/m^2$ (overweight), $25.0{\sim}29.9kg/m^2$ (moderate obesity) and $30.0kg/m^2$~ (severe obesity) according to the Asia Pacific Standards of WHO recommended definition of obesity. Screening rates of breast and cervical cancer were estimated by the recommendation of the National Cancer Screening Program of the National Cancer Center, Korea. Results : The overall screening rates for breast and cervical cancer were 51.3% and 50.1%, respectively. After covariate adjustment, the screening rates for breast cancer (adjusted odds ratio, 0.70; 95% confidence interval, 0.51 to 0.97) and cervical cancer (adjusted odds ratio, 0.71; 95% confidence interval, 0.53 to 0.94) were significantly lower in the women with severe obesity. Conclusion: Obesity is associated with lower compliance with breast and cervical cancer screening guidelines in Korean women.

• Journal of Preventive Medicine and Public Health
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• 제41권6호
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• pp.407-412
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• 2008

Objectives: The purpose of this study was to evaluate the relationship of nonalcoholic fatty liver and cardiovascular risk factors. Methods: This study was conducted to investigate the association of nonalcoholic fatty liver and cardiovascular risk factors for adult men (n=2976) and women (n=2442) who were over 19 years old, after excluding the HBsAg(+) or anti-HCV(+) patients and the men and women with increased alcohol intake (men: 40g/week, women: 20g/week). Results: Compared with the normal liver subjects, the nonalcoholic fatty liver subjects showed a significantly increased frequency of abnormal systolic blood pressure (${geq}120mmHg$), fasting blood sugar (${\geq}100mg/dL$), total cholesterol ($({\geq}200 mg/dL$), triglyceride ($({\geq}150mg/dL$), high density lipoprotein cholesterol (<40 mg/dL), low density lipoprotein cholesterol ($({\geq}130g\; m/dL$) and abdominal obesity in men, and all these measures were significantly increased in the women except for abnormal HDL cholesterol. After adjusting for the body mass index, age, smoking, exercise and a nonalcoholic liver, the odds ratios of an abnormal waist hip ratio were 1.35(95% Confidence Interval=1.05-4.72) in the mild fatty liver, 1.61 (1.19-2.18) in the moderate fatty liver, 2.77(1.57-4.92) in the severe fatty liver compared with a normal liver. The adjusted odds ratios for abnormal fasting blood sugar were 1.26(1.03-1.53) in the mild fatty liver, 1.62(1.27-2.06) in the moderate fatty Iiver and 1.77(1.12-2.78) in the severe fatty liver. The adjusted odds ratios for abnormal triglyceride were 1.38(1.11-1.72) in the mild fatty liver, 1.73(0.33-2.24) in the moderate fatty liver and 1.91 (1.17-3.10) in the severe fatty liver of men. Adjusted odds ratios for abnormal triglyceride were 1.50(1.04-2.15) in mild, 1.71(1.07-2.68) in moderate, 1.81(0.69-4.38) in severe fatty liver of women. Conclusions: The nonalcoholic fatty liver subjects had more cardiovascular risk factors compared with the normal liver subjects. Thus, prevention and treatment of the nonalcoholic fatty liver is necessary by lifestyle modifications such as restriction of alcohol intake, no smoking, exercise and adequate eating habits.

• Korean Journal of Radiology
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• 제24권9호
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• pp.849-859
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• 2023

Objective: The prognostic value of the volume and density of skeletal muscles in the abdominal waist of patients with colon cancer remains unclear. This study aimed to investigate the association between the automated computed tomography (CT)-based volume and density of the muscle in the abdominal waist and survival outcomes in patients with colon cancer. Materials and Methods: We retrospectively evaluated 474 patients with colon cancer who underwent surgery with curative intent between January 2010 and October 2017. Volumetric skeletal muscle index and muscular density were measured at the abdominal waist using artificial intelligence (AI)-based volumetric segmentation of body composition on preoperative pre-contrast CT images. Patients were grouped based on their skeletal muscle index (sarcopenia vs. not) and muscular density (myosteatosis vs. not) values and combinations (normal, sarcopenia alone, myosteatosis alone, and combined sarcopenia and myosteatosis). Postsurgical disease-free survival (DFS) and overall survival (OS) were analyzed using univariable and multivariable analyses, including multivariable Cox proportional hazard regression. Results: Univariable analysis showed that DFS and OS were significantly worse for the sarcopenia group than for the non-sarcopenia group (P = 0.044 and P = 0.003, respectively, by log-rank test) and for the myosteatosis group than for the non-myosteatosis group (P < 0.001 by log-rank test for all). In the multivariable analysis, the myosteatotic muscle type was associated with worse DFS (adjusted hazard ratio [aHR], 1.89 [95% confidence interval, 1.25-2.86]; P = 0.003) and OS (aHR, 1.90 [95% confidence interval, 1.84-3.04]; P = 0.008) than the normal muscle type. The combined muscle type showed worse OS than the normal muscle type (aHR, 1.95 [95% confidence interval, 1.08-3.54]; P = 0.027). Conclusion: Preoperative volumetric sarcopenia and myosteatosis, automatically assessed from pre-contrast CT scans using AI-based software, adversely affect survival outcomes in patients with colon cancer.