Won Kyung Lee

The Effect of Eating Behavior on Being Overweight or Obese During Preadolescence

Objectives Being overweight or obese is central to metabolic syndrome, and these characteristics constitute dominant risk factors for chronic diseases. Although behavioral factors, including eating habits and sedentary lifestyles, are considered to be determinants of obesity, the specific childhood factors that contribute to this condition have not been clearly defined. Methods The subjects consisted of 261 children aged 7-9 years who were recruited from an elementary school during October 2003. Information was obtained from their parents using a questionnaire focused on eating behaviors and lifestyle factors, additional data were also collected via anthropometric measurements and biochemical examinations, including blood tests. Results A total of 48 (18.4%) of the 261 children were overweight, and 34 (70.8%) had at least one other component of metabolic syndrome. Eating behaviors emerged as significant lifestyle-related risk factors for being overweight or obese. Those who engaged in overeating more than twice per week had three times the risk of being overweight (odds ratio [OR], 3.10, 95% confidence interval [CI], 1.39 to 6.92), and those who ate rapidly had three times the risk of being overweight (OR, 3.28; 95% CI, 1.68 to 6.41). Those who had fewer family meals (fewer than 2-3/month) had a nine times higher risk of being overweight than those who had family meals more frequently (at least 1/day) (OR, 9.51; 95% CI, 1.21 to 74.82). Conclusions This study showed that being overweight or obese during preadolescence is associated with a higher risk of metabolic syndrome and is related to unhealthy eating behaviors. Thus, weight-control strategies and healthy eating behaviors should be developed early in life to reduce the risk for metabolic syndrome.

Disability-adjusted Life Years for 313 Diseases and Injuries: the 2012 Korean Burden of Disease Study

This study is part of a 5-year research project on the national burden of diseases, injuries, and risk factors in Korea. Using disability-adjusted life years (DALYs), a metric introduced by the 1990 Global Burden of Disease (GBD) project, we performed a comprehensive and detailed assessment of the magnitude and distribution of both fatal and non-fatal health problems in the Korean population. The concept and general approach were consistent with the original GBD study, with some methodological modifications to make the study more suitable for Korea. We computed DALYs for 313 causes in both sexes and nine age groups using the entire populations medical records and newly generated Korean disability weights. In 2012, the dominant disease burden was non-communicable diseases, which accounted for 85.21% of total DALYs, while injuries accounted for 7.77% and communicable, maternal, neonatal, and nutritional disorders for 7.02%. Of the total DALYs, 88.67% were from years lived with disability and 11.32% were from years of life lost due to premature mortality. Diabetes mellitus was the leading cause of DALYs, followed by low back pain, chronic obstructive pulmonary disease, ischemic heart disease, ischemic stroke, cirrhosis of the liver, falls, osteoarthritis, motorized vehicle with three or more wheels, and self-harm. The results reported here identify key health challenges and opportunities for future health interventions and policy changes, and provide information that will help assess the major public health issues in Korea, a nation faced with one of the worlds most rapidly ageing populations.

Risks of Lung Cancer due to Radon Exposure among the Regions of Korea

Radon is likely the second most common cause of lung cancer after smoking. We estimated the lung cancer risk due to radon using common risk models. Based on national radon survey data, we estimated the population-attributable fraction (PAF) and the number of lung cancer deaths attributable to radon. The exposure-age duration (EAD) and exposure-age concentration (EAC) models were used. The regional average indoor radon concentration was 37.5 95 Bq/m3. The PAF for lung cancer was 8.3% (European Pooling Study model), 13.5% in males and 20.4% in females by EAD model, and 19.5% in males and 28.2% in females by EAC model. Due to differences in smoking by gender, the PAF of radon-induced lung cancer deaths was higher in females. In the Republic of Korea, the risk of radon is not widely recognized. Thus, information about radon health risks is important and efforts are needed to decrease the associated health problems. Graphical Abstract

Change in Causes of Injury-Related Deaths in South Korea, 1996–2006

Background The aims of this study were to describe temporal patterns of injury-related mortality by sex, age group, and mechanism, and to identify changes in the leading causes of injury-related deaths in South Korea from 1996 through 2006. Methods This retrospective, descriptive study analyzed national data on all injury-related deaths reported in official death certificates from 1996–2006. Incidence rates of fatal injuries are presented as crude and age-standardized rates per 100 000 population, and percentage changes in injury-related mortalities over the 11-year period were calculated with respect to intention, sex, and age. The 4 most common mechanisms (fall, poisoning, suffocation, and drowning) were then classified as unintentional injuries or suicides. Results Overall injury-related mortality decreased 31.7% during the study period (1996–2006). Despite this overall decreasing trend, injury-related mortality increased among adults aged 65 years or older. In particular, injury-related mortality among women older than 80 years doubled since 1996. Suicide replaced transport as the leading cause of injury-related deaths between 2003 and 2006. With regard to intention, sex, and age, the most noticeable changes during the study period were increases in unintentional fall among elderly adults and suicidal fall among adolescents. Conclusions The incidence rate for all injuries generally decreased from 1996–2006. However, the incidence rate of fall injuries increased among elderly adults, and suicide increased among adolescents. These findings suggest that further investigation of the characteristics and trends of injuries is necessary to develop and implement effective interventions.

Effect of Preexisting Musculoskeletal Diseases on the 1-Year Incidence of Fall-related Injuries

Objectives People who have chronic diseases, as well as gait imbalance or psychiatric drug use, may be susceptible to injuries from falls and slips. The purpose of this study was to evaluate the effect of musculoskeletal diseases on incidental fall-related injuries among adults in Korea. Methods We analyzed data from the 4th Korea National Health and Nutrition Examination Survey (2007-2009), which are national data obtained by a rolling survey sampling method. The 1-year incidence of fall-related injuries was defined by health service utilization within the last year due to injury occurring after a slip and fall, and musculoskeletal diseases included osteoarthritis, rheumatoid arthritis, osteoporosis, and back pain. To evaluate the effects of preexisting musculoskeletal diseases, adults diagnosed before the last year were considered the exposed group, and adults who had never been diagnosed were the unexposed group. Results The weighted lifetime prevalence of musculoskeletal disease was 32 540 per 100 000 persons. Musculoskeletal diseases were associated with a higher risk of fall-related injury after adjustment for sex, age, residence, household income, education, occupation, visual disturbance, paralysis due to stroke, and medication for depression (odds ratio [OR], 1.41; 95% confidence interval [CI], 1.03 to 1.93). As the number of comorbid musculoskeletal diseases increased, the risk of fall-induced injuries increased (p-value for trend <0.001). In particular, patients who had any musculoskeletal condition were at much higher risk of recurrent fall-related injuries (OR, 6.20; 95% CI, 1.06 to 36.08). Conclusions One must take into account the risk of fall-related injuries and provide prevention strategies among adults who have musculoskeletal diseases.

Modifying effect of heat waves on the relationship between temperature and mortality

Studies conducted to evaluate temporal trends of heat-related mortality have not considered the effects of heat waves; although it is known they can affect mortality and act as a modifying factor. After adjusting for long-term trends and seasonality, the effects of temperature on non-accidental deaths in Seoul and Busan (inland and coastal cities, respectively) were analyzed using a generalized additive model of Poisson distribution. We evaluated temporal trends of heat-related mortalities in four periods (1991-1995, 1996-2000, 2001-2005, and 2006-2012). The effects of temperature on mortality were evaluated according to the occurrence of a heat wave and results were compared in the two cities. The effect of temperature on mortality was the greatest in 1991-1995 in Seoul; no significant change was observed in Busan. When we stratified the study period by heat wave status, the risk increase in mortality was 15.9% per 1℃ during years with a heat wave in Seoul, which was much higher than 0.31% increase observed during years without a heat wave. On the other hand, Busan showed a linear relationship between temperature and mortality and no significant difference between years with or without a heat wave. Variations in the relationship between temperature and mortality could be misunderstood if heat waves are not considered. Furthermore, heterogeneity was found in the modifying effect of heat waves on heat-related mortality in inland and coastal cities. The findings of this study help understand relations between temperature and mortality.

Digital breast tomosynthesis and breast ultrasound: Additional roles in dense breasts with category 0 at conventional digital mammography

PURPOSE To compare the diagnostic performances of digital breast tomosynthesis (DBT) and ultrasound for the dense breasts with category 0 at conventional digital mammography. MATERIALS AND METHODS This retrospective study was approved by the institutional review board, and informed consent was waived. Among the 1103 patients who underwent screening digital mammography at our institution, 769 (69.7%) patients had dense breasts. Of the 769 patients, 229 (29.8%) lesions were categorized as 0. DBT, breast ultrasound and digital mammography were performed in 108 (47.2%) patients. BI-RADS final assessments for DBT and ultrasound were recorded. Categories 1-3 were clinically considered as benign, and categories 4 and 5 were clinically considered as malignant. The diagnostic performances of breast ultrasound and DBT were correlated with final pathologic reports or follow-up images. RESULTS Among 108 lesions, 17 (15.7%) were malignant and 91 (84.3%) were benign. Sensitivity was 100% for both ultrasound (17/17) and DBT (17/17) and negative predictive value was also 100% for both ultrasound (49/49) and DBT (74/74). Specificity and positive predictive value for ultrasound were 53.9% (49/91) and 28.8% (17/59), respectively. Specificity and positive predictive value for DBT were 81.3% (74/91) and 50% (17/34), respectively. DBT showed higher diagnostic accuracy than that of breast ultrasound (DBT: 84.3%, 91/108; ultrasound: 61.1%, 66/108; p<0.001). The benign biopsy rate of DBT (50%, 17/34) was lower than that of ultrasound (71.2%, 42/59). CONCLUSION DBT showed better diagnostic performance than breast ultrasound for dense breasts with category 0. DBT may reduce the benign biopsy rate and short term follow-up.

The population attributable fraction of low education for mortality in South Korea with improvement in educational attainment and no improvement in mortality inequalities

BackgroundThe educational attainment of Koreans has greatly increased, which was expected to reduce the magnitude of the population attributable fraction (PAF) of mortality associated with low education levels. However, increase in the relative risk (RR) of mortality among those with lower educational levels actually increased the PAF. The purpose of this study was to examine the change in the PAF of lower educational levels for mortality in Korea, where educational attainment has improved and is associated with the exacerbation of inequalities in mortality levels.MethodsNational census data were used to derive educational levels. The mortality-associated RR of lower educational levels was calculated by reference to national census and death certificate data from 1995, 2000, 2005, and 2010. PAFs were calculated for all-cause mortality, malignant neoplasms, cerebrovascular disease, heart disease, and suicide by gender and age group (30–44 and 45–59 years).ResultsThe PAF of low educational level in terms of total mortality has decreased since 1995 in both genders. This trend was more prominent among those aged 30–44 years. However, the PAFs of suicide in younger females (30–44 years) and of cerebrovascular disease in older males (45–59 years) have increased. The RRs of all-cause mortality and those of the four leading causes of death in those with the lowest educational levels have increased, especially in females aged 30–44 years.ConclusionsThe consistent and sharp increase in the attainment of education has contributed to the reduction in the PAFs of lower education for mortality, despite the fact that mortality inequalities have not improved. Efforts to reduce health inequalities must promote healthy public policy and address public health policies.

Disability-adjusted Life Years (DALYs) for Mental and Substance Use Disorders in the Korean Burden of Disease Study 2012

The purpose of this study was to estimate the national burden of mental substance disorders on medical care utilization in Korea using National Health Insurance System (NHIS) data and updated disability weight, in terms of disability-adjusted life years (DALYs). For each of the 24 disorders, the incident years lived with disability (YLDs) was calculated, using NHIS data to estimate prevalence and incidence rates. The DisMod-II software program was used to model duration and remission. The years of life lost (YLLs) due to premature death were calculated from causes of death statistics. DALYs were computed as the sum of YLDs and YLLs, and time discounting and age weighting were applied. The year examined was 2012, and the subjects were divided into 9 groups according to age. In 2012, the Korean burden of mental and substance use disorders was 945,391 DALYs. More than 98% of DALYs were from YLDs, and the burden in females was greater than that in males, though the burden in males aged less than 19 years old was greater than that in females. Unipolar depressive disorders, schizophrenia, and anxiety disorders were found to be major diseases that accounted for more than 70% of the burden, and most DALYs occurred in their 30–59. Mental and substance use disorders accounted for 6.2% of the total burden of disease and were found to be the 7th greatest burden of disease. Therefore, mental and substance use disorders need to be embraced by mainstream health care with resources commensurate with the burden.

Public Awareness of Stroke and Its Predicting Factors in Korea: a National Public Telephone Survey, 2012 and 2014

The aim of this study was to investigate time trends in the public awareness of stroke and its predicting factors. The target population was 9,600 community-dwelling adults, aged 19–79 years, in 16 metropolitan cities and provinces in Korea. The survey samples in 2012 and 2014 were selected separately (entirely different sets of subjects) using a proportionate quota sampling method. Information concerning knowledge of stroke and demographics was collected by trained telephone interviewers using random digit dialing. After excluding subjects with a non-response or refusal to answer any question, the analyses included 8,191 subjects in 2012 and 8,127 subjects in 2014. Respondents’ awareness of stroke warning signs (numbness or weakness, difficulty speaking or understanding speech, dizziness, visual impairment, and severe headache) was highest for difficulty speaking or understanding speech (80.9% in 2012 and 86.4% in 2014). There were significant increases in the proportion of respondents understanding the appropriate action (i.e., calling an ambulance) at the time of stroke occurrence (59.6% to 67.1%), and in the proportion aware of the general need for prompt treatment (86.7% to 89.8%). In multivariable logistic regression analysis, older age, higher education level, higher household income, current non-smoking, exposure to stroke-related public relations materials, and experience of stroke education were significantly associated with both high knowledge of stroke warning signs and awareness of the need for prompt treatment. Between 2012 and 2014, the public’s awareness of stroke increased significantly. More specialized interventions, including public relations materials and education, should focus on subgroups who have lower stroke knowledge.