Detection of Tick-Borne Pathogens in the Korean Water Deer (Hydropotes inermis argyropus) from Jeonbuk Province, Korea

The objective of this study was to investigate the prevalence of tick-borne pathogens in the Korean water deer (Hydropotes inermis argyropus). Pathogens were identified using PCR which included Anaplasma, Ehrlichia, Rickettsia, and Theileria. Rickettsia was not detected, whereas Anaplasma, Ehrlichia, and Theileria infections were detected in 4, 2, and 8 animals, respectively. The most prevalent pathogen was Theileria. Of the 8 Theileria-positive animals, 2 were mixed-infected with 3 pathogens (Anaplasma, Ehrlichia, and Theileria) and another 2 animals showed mixed-infection with 2 pathogens (Anaplasma and Theileria). Sequencing analysis was used to verify the PCR results. The pathogens found in this study were identified as Anaplasma phagocytophilum, Ehrlichia canis, and Theileria sp. To the best of our knowledge, this is the first report identifying these 3 pathogens in the Korean water deer. Our results suggest that the Korean water deer may serve as a major reservoir for these tick-borne pathogens, leading to spread of tick-borne diseases to domestic animals, livestock, and humans. Further studies are needed to investigate their roles in this respect.

Geographic Distribution of Urologists in Korea, 2007 to 2012

The adequacy of the urologist work force in Korea has never been investigated. This study investigated the geographic distribution of urologists in Korea. County level data from the National Health Insurance Service and National Statistical Office was analyzed in this ecological study. Urologist density was defined by the number of urologists per 100,000 individuals. National patterns of urologist density were mapped graphically at the county level using GIS software. To control the time sequence, regression analysis with fitted line plot was conducted. The difference of distribution of urologist density was analyzed by ANCOVA. Urologists density showed an uneven distribution according to county characteristics (metropolitan cities vs. nonmetropolitan cities vs. rural areas; mean square=102.329, P<0.001) and also according to year (mean square=9.747, P=0.048). Regression analysis between metropolitan and non-metropolitan cities showed significant difference in the change of urologists per year (P=0.019). Metropolitan cities vs. rural areas and non-metropolitan cities vs. rural areas showed no differences. Among the factors, the presence of training hospitals was the affecting factor for the uneven distribution of urologist density (P<0.001).Uneven distribution of urologists in Korea likely originated from the relatively low urologist density in rural areas. However, considering the time sequencing data from 2007 to 2012, there was a difference between the increase of urologist density in metropolitan and non-metropolitan cities.

Effects of the Periodical Spread of Rinderpest on Famine, Epidemic, and Tiger Disasters in the late 17th Century / 의사학

This study clarifies the causes of the repetitive occurrences of such phenomena as rinderpest, epidemic, famine, and tiger disasters recorded in the Joseon Dynasty Chronicle and the Seungjeongwon Journals in the period of great catastrophe, the late 17th century in which the great Gyeongsin famine (1670~1671) and the great Eulbyeong famine (1695~1696) occurred, from the perspective that they were biological exchanges caused by the new arrival of rinderpest in the early 17th century. It is an objection to the achievements by existing studies which suggest that the great catastrophes occurring in the late 17th century are evidence of phenomena in a little ice age. First of all, rinderpest has had influence on East Asia as it had been spread from certain areas in Machuria in May 1636 through Joseon, where it raged throughout the nation, and then to the west part of Japan. The new arrival of rinderpest was indigenized in Joseon, where it was localized and spread periodically while it was adjusted to changes in the population of cattle with immunity in accordance with their life spans and reproduction rates. As the new rinderpest, which showed high pathogenicity in the early 17th century, was indigenized with its high mortality and continued until the late 17th century, it broke out periodically in general. Contrastively, epidemics like smallpox and measles that were indigenized as routine ones had occurred constantly from far past times. As a result, the rinderpest, which tried a new indigenization, and the human epidemics, which had been already indigenized long ago, were unexpectedly overlapped in their breakout, and hence great changes were noticed in the aspects of the human casualty due to epidemics. The outbreak of rinderpest resulted in famine due to lack of farming cattle, and the famine caused epidemics among people. The casualty of the human population due to the epidemics in turn led to negligence of farming cattle, which constituted factors that triggered rage and epidemics of rinderpest. The more the number of sources of infection and hosts with low immunity increased, the more lost human resources and farming cattle were lost, which led to a great famine. The periodic outbreak of the rinderpester along with the routine prevalence of various epidemics in the 17thcentury also had influenced on domestic and wild animals. Due to these phenomenon, full-fledged famines occurred that were incomparable with earlier ones. The number of domestic animals that were neglected by people who, faced with famines, were not able to take care of them was increased, and this might have brought about the rage of epidemics like rinderpest in domestic animals like cattle. The great Gyeongsin and Eulbyeong famines due to reoccurrence of the rinderpest in the late 17th century linked rinderpester, epidemics and great famines so that they interacted with each other. Furthermore, the recurring cycle of epidemics-famines-rinderpest-great famines constituted a great cycle with synergy, which resulted in eco-economic-historical great catastrophes accompanied by large scale casualties. Therefore, the Gyeongsin and Eulbyeong famines occurring in the late 17th century can be treated as events caused by the repetition of various periodic disastrous factors generated in 1670~1671 and in 1695~1696 respectively, and particularly as phenomena caused by biological exchanges based on rinderpester., rather than as little ice age phenomena due to relatively long term temperature lowering.

Prevalence and Risk Factors of Clonorchiasis among Residents of Riverside Areas in Muju-gun, Jeollabuk-do, Korea

We evaluated the status of Clonorchis sinensis infection and potential risk factors among residents of riverside areas (Geumgang) in Muju-gun, Jeollabuk-do (Province), Korea. From January to February 2010, a total of 349 (171 males, 178 females) stool samples were collected and examined by the formalin-ether concentration technique. Also, village residents were interviewed using questionnaires to obtain information about C. sinensis infection-related risk factors. Overall egg-positive rate of C. sinensis was 13.2%. Egg-positive rates were significantly higher in males, farmers, and residents who had lived there more than 20 years, and in residents who had eaten raw freshwater fish than in opposite groups, respectively. However, there was no significant difference between age groups, education levels, cigarette smoking, alcohol drinking, health status, past history of infection, and experience of clonorchiasis medication and examination. Logistic regression analysis was performed to determine risk factors for clonorchiasis. On univariate analysis, the odds ratios for males, farmers, those who had lived there more than 20 years, and who had eaten raw freshwater fish were 2.41, 4.44, 3.16, and 4.88 times higher than those of the opposites, respectively. On multivariate analysis, the odds ratio of residents who had eaten raw freshwater fish was 3.2-fold higher than that of those who had not. These results indicate that residents living in Muju-gun, along the Geum River, Korea, have relatively high C. sinensis egg-positive rates, and the habit of eating raw freshwater fish was the major factor for the maintenance of clonorchiasis.

Intestinal Helminthic Infections in Striped Field Mice, Apodemus agrarius, from Two Southern Regions of Korea

The present study was performed to know the infection status of intestinal helminths in a most common species of field mice, Apodemus agrarius, from 2 southern regions of Korea. Total 133 and 103 mice were collected by the mouse trap in Hapcheon-gun, Gyeongsangnam-do and Gurye-gun, Jeollanam-do, respectively, from July 2005 to June 2006. The small intestine of each mouse was resected and longitudinally opened with a pair of scissors. The intestinal contents were washed with 0.85% saline until the supernatant became clear. Helminths were collected with naked eyes or under a stereomicroscope from the sediment of the intestinal content. More than 11 species of helminths (4 nematode spp., 5 trematode spp., and 2 cestode spp.) were recovered. Among these, heligmosomoid nematodes (97.5%) was the most highly and heavily infected species. As the members of trematodes, Plagiorchis muris, Brachylaima sp., Echinostoma hortense, Echinostoma cinetorchis, and unidentified echinostome larvae were found in the small intestines of 35 (14.8%), 12 (5.1%), 6 (2.5%), 1 (0.4%), and 1 (0.4%) mice respectively. Two species of tapeworms, Hymenolepis nana and Hymenolepis diminuta were also detected in 79 (33.5%) and 21 (8.9%) mice, respectively. Conclusively, heligmosomoid nematodes were the most prevalent (dominant) species among more than 11 helminth species detected, and Brachylaima sp. fluke is newly added in the list of intestinal trematodes in Korea.

A Nationwide Epidemiological Study of Testicular Torsion in Korea

Testicular torsion is a surgical emergency in the field of urology. Knowledge of the epidemiology and pathophysiology is significant to an urologist. However, the epidemiology of testicular torsion in Korea has not been studied. We performed a nationwide epidemiological study to improve knowledge of the epidemiology of testicular torsion. From 2006-2011, the Korean Urologic Association began the patient registry service. The annual number of patients with testicular torsion from 2006 to 2011 were 225, 250, 271, 277, 345, and 210, respectively. The overall incidence of testicular torsion in males was 1.1 per 100,000; However, the incidence in men less than 25 yr old was 2.9 per 100,000. Adolescents showed the highest incidence. Total testicular salvage rate was 75.7% in this survey. There was no geographic difference of testicular salvage rate. Minimizing the possibility of orchiectomy for testicular torsion is important to improve public awareness to expedite presentation and provider education to improve diagnosis and surgery.

Prevalence of Dirofilaria immitis Infection in Stray Cats by Nested PCR in Korea

The purpose of this study was to conduct a survey of Dirofilaria immitis infection among stray cats in Korea using nested PCR. We included 235 stray cats (121 females and 114 males) and evaluated each for the presence of feline heartworm infection. Blood samples were collected from 135 cats in Daejeon, 50 cats in Seoul, and 50 cats from Gyeonggi-do (Province). Of the 235 DNA samples, 14 (6.0%) were positive for D. immitis. The prevalence of infection in male cats (8/114, 7.0%) tended to be higher than that in female cats (6/121, 5.0%), but the difference was not statistically significant. In each location, 8, 2, and 4 cats were positive for infection, respectively, based on DNA testing. No significant differences in the prevalence were observed among the geographic regions, although the rate of infection was higher in Gyeonggi-do (8.0%) than Daejeon (5.9%) and Seoul (4.0%). We submitted 7 of the 14 D. immitis DNA-positive samples for sequencing analysis. All samples corresponded to partial D. immitis cytochrome c oxidase subunit I gene sequences with 99% homology to the D. immitis sequence deposited in GenBank (accession no. FN391553). To the best of our knowledge, this is the first survey using nested PCR to analyze the prevalence of D. immitis in stray cats in Korea.

Development and Application of Chronic Disease Risk Prediction Models

Currently, non-communicable chronic diseases are a major cause of morbidity and mortality worldwide, and a large proportion of chronic diseases are preventable through risk factor management. However, the prevention efficacy at the individual level is not yet satisfactory. Chronic disease prediction models have been developed to assist physicians and individuals in clinical decision-making. A chronic disease prediction model assesses multiple risk factors together and estimates an absolute disease risk for the individual. Accurate prediction of an individual's future risk for a certain disease enables the comparison of benefits and risks of treatment, the costs of alternative prevention strategies, and selection of the most efficient strategy for the individual. A large number of chronic disease prediction models, especially targeting cardiovascular diseases and cancers, have been suggested, and some of them have been adopted in the clinical practice guidelines and recommendations of many countries. Although few chronic disease prediction tools have been suggested in the Korean population, their clinical utility is not as high as expected. This article reviews methodologies that are commonly used for developing and evaluating a chronic disease prediction model and discusses the current status of chronic disease prediction in Korea.

Development and Application of Chronic Disease Risk Prediction Models

Currently, non-communicable chronic diseases are a major cause of morbidity and mortality worldwide, and a large proportion of chronic diseases are preventable through risk factor management. However, the prevention efficacy at the individual level is not yet satisfactory. Chronic disease prediction models have been developed to assist physicians and individuals in clinical decision-making. A chronic disease prediction model assesses multiple risk factors together and estimates an absolute disease risk for the individual. Accurate prediction of an individual's future risk for a certain disease enables the comparison of benefits and risks of treatment, the costs of alternative prevention strategies, and selection of the most efficient strategy for the individual. A large number of chronic disease prediction models, especially targeting cardiovascular diseases and cancers, have been suggested, and some of them have been adopted in the clinical practice guidelines and recommendations of many countries. Although few chronic disease prediction tools have been suggested in the Korean population, their clinical utility is not as high as expected. This article reviews methodologies that are commonly used for developing and evaluating a chronic disease prediction model and discusses the current status of chronic disease prediction in Korea.

Seroprevalence of Encephalitozoon cuniculi in Pet Rabbits in Korea

Encephalitozoon cuniculi is a microsporidian parasite commonly found in rabbits that can infect humans, causing encephalitozoonosis. The prevalence of encephalitozoonosis is not well documented, even when many clinics suspect pet rabbits as being highly infected. This study investigated the seropositivity of E. cuniculi using ELISA. The examination of 186 rabbits using ELISA showed that 22.6% (42/186) were seropositive against E. cuniculi. In analysis with healthy status, all 42 seropositive sera were collected from clinically normal rabbits. Moreover, the gender and age of pet rabbits did not have anysignificant effect on E. cuniculi infection. To the best of our knowledge, this is the first report to describe the seroprevalence of E. cuniculi in pet rabbits and suggests that pet rabbits could act as an important reservoir of encephalitozoonosis for both pet animals and humans in Korea.

Cyberbullying, Problematic Internet Use, and Psychopathologic Symptoms among Korean Youth

To evaluate the associations between cyberbullying behaviors and problematic internet use, and to compare psychopathologic symptoms in victims, perpetrators, and victims-perpetrators of cyberbullying to those in youths who were not involved in cyberbullying. A total of 4531 youths (11-14 years of age) were recruited from elementary and middle schools. Among 4531 youths, 9.7% were involved in cyberbullying; 3.3% were only victims; 3.4% were only perpetrators; and 3.0% were victims-perpetrators. Cyberbullying behaviors were associated with problematic internet use as well as various psychopathologic symptoms. Depressive symptoms were associated with cyberbullying victimization, and rule-breaking behaviors and aggressive behaviors have relevance to cyberbullying perpetration. Greater attention needs to be paid to identify youths earlier who are involved in cyberbullying and prevent serious adverse consequences in them.

Environmental Factors Related to Enterobiasis in a Southeast Region of Korea

Pinworm infection can occur through contact with contaminated surfaces followed by ingestion or even through inhalation of infective eggs. We have limited information regarding environmental contamination by eggs of Enterobius vermicularis. In order to determine environmental risk factors associated with the rate of E. vermicularis infection, we investigated possible environmental risk factors using a questionnaire from 46 kindergartens in 3 different cities of the southeast area of Korea. In total, using the cellotape anal swab technique, 3,422 children were examined for E. vermicularis infection. We evaluated E. vermicularis egg of books, educational materials, toys, room door handles, dusts of window edges, desks, chairs, tables, and dusts of classrooms. The overall egg-positive rate for E. vermicularis was 6.0%, and the prevalence of enterobiasis in each kindergarten ranged between 0% and 16.9%. We found that 78.9% of egg positive kindergartens were managed by private foundations, which was significantly higher, compared with kindergartens managed by public foundations or the nation. Compared with public or national kindergartens, most private kindergartens were located in residential areas and the number of children in these areas was significantly higher. In conclusion, numbers of children in kindergartens was found to be an environmental risk factor associated with transmission of enterobiasis in Korea.

Comparison of clinical characteristics between healthcare-associated pneumonia and community-acquired pneumonia in patients admitted to secondary hospitals

BACKGROUND: Since healthcare-associated pneumonia (HCAP) is heterogeneous, clinical characteristics and outcomes are different from region to region. There can also be differences between HCAP patients hospitalized in secondary or tertiary hospitals. This study aimed to evaluate the clinical characteristics of HCAP patients admitted into secondary community hospitals. METHODS: This was a retrospective study conducted in patients with HCAP or community-acquired pneumonia (CAP) hospitalized in two secondary hospitals between March 2009 and January 2011. RESULTS: Of a total of 303 patients, 96 (31.7%) had HCAP. 42 patients (43.7%) resided in a nursing home or long-term care facility, 36 (37.5%) were hospitalized in an acute care hospital for > 2 days within 90 days, ten received outpatient intravenous therapy, and eight attended a hospital clinic or dialysis center. HCAP patients were older. The rates of patients with CURB65 scores of 3 or more (22.9% vs. 9.1%; p = 0.001) and PSI class IV or more (82.2% vs. 34.7%; p < 0.001) were higher in the HCAP group. Drug-resistant pathogens were more frequently detected in the HCAP group (23.9% vs. 0.4%; p < 0.001). However, Streptococcus pneumoniae was the most common pathogen in both groups. The rates of antibiotic change, use of inappropriate antibiotics, and failure of initial antibiotic therapy in the HCAP group were significantly higher. Although the overall survival rate of the HCAP group was significantly lower (82.3% vs. 96.8%; p < 0.001), multivariate analyses failed to show that HCAP itself was a prognostic factor for mortality (p = 0.826). Only PSI class IV or more was associated with increased mortality (p = 0.005). CONCLUSIONS: HCAP should be distinguished from CAP because of the different clinical features. However, the current definition of HCAP does not appear to be a prognostic for death. In addition, the use of broad-spectrum antibiotics for HCAP should be reassessed because S. pneumoniae was most frequently identified even in HCAP patients.

Trend of Mortality Rate and Injury Burden of Transport Accidents, Suicides, and Falls / 예방의학회지

OBJECTIVES: Recently injury has become a major world-wide health problem. But studies in Korea about injuries were very few. Thus, this study was conducted to analyze the trend of major injuries from 1991 to 2006 and to provide basic data for preventing injuries. METHODS: This study was based on the National Statistical Office data from 1991 to 2006 and calculated to estimate the burden of major injuries by using the standard expected years of life lost (SEYLL) and total lost earnings equation. RESULTS: For transport accidents, mortality, SEYLL and total lost earnings were increased from 1991 to 1996 and decreased from 2000 to 2006. On the other hand, for suicides, these were increased gradually. Since 2003, falls were included in ten leading causes of death. This study showed that injury causes major social and economical losses. CONCLUSIONS: We could reduce injury related premature death through active interest in injury prevention program.

Cerebrovascular Disease and Stroke in Korean Male Adolescent

PURPOSE: This study aimed to estimate the prevalence and incidence of cerebrovascular disease (CVD) and stroke in Korean male adolescents. MATERIALS AND METHODS: The authors reviewed all medical certificates, medical records, and radiologic images from the examinations of Korean military conscription from January 2008 to May 2011. RESULTS: Of the 101156 examinees, 40 had CVD and stroke during adolescence. The overall prevalence and incidence of CVD and stroke was 39.54 cases per 100000 adolescents and 2.08 cases per 100000 adolescents per year, respectively and these were similar to the worldwide data. There were 3 cases of aneurysm, 3 cases of dural arteriovenous fistula, 11 cases of arteriovenous malformation, 4 cases of cavernous hemangioma, 4 cases of cerebrovascular infarction, 16 cases of Moyamoya disease, and 1 case of missing data. The incidence of arteriovenous malformation (0.57 cases per 100000 adolescents per year) was lower than the incidence for the worldwide general population. The incidence of Moyamoya disease was higher than that in any other country (15.82 cases per 100000 adolescents, vs. 0.83 cases per 100000 adolescents per year). CONCLUSION: We observed ischemic and hemorrhagic stroke, each accounting for approximately half of cases, and high incidence of Moyamoya disease with low incidence of arteriovenous malformation in Korean male adolescents.

Bell's Phenomenon during Screening Examination for Retinopathy of Prematurity

PURPOSE: Bell's phenomenon (BP), which may disturb screening examinations for retinopathy of prematurity (ROP), is known to present infrequently in premature babies. Stress associated with the examinations can influence expression of BP. The authors of the present study evaluated BP during examinations for ROP. METHODS: The present study included 102 eyes of 51 premature babies. Expression of BP was assessed at 3 steps of the examination in the following order: after insertion of a speculum, after illumination of an indirect ophthalmoscope and after scleral depression. The relationship between the expression of BP and the gestational age at the examination was analyzed in each step of the examination. RESULTS: The frequency of BP after the speculum insertion and the illumination was 77% to 92% in infants 32 weeks of age or younger, and decreased significantly to 16% to 57% in infants 42 weeks of age or older (p < 0.005). BP after the scleral depression had no significant association with the gestational age. Frequency of BP increased significantly as the steps of the examination proceeded (p < 0.01). CONCLUSIONS: BP was frequent in premature infants during ROP examination in spite of neurological immaturity. The examiner should take BP into consideration, which frequently occurs in younger infants.

A Surge in the Seroprevalence of Toxoplasmosis among the Residents of Islands in Gangwha-gun, Incheon, Korea

Seroepidemiological changes of Toxoplasma gondii infection among the residents of the islands of Gangwha-gun, Incheon for 2 years were surveyed and evaluated by ELISA using a crude extract antigen. In 2010, sera of 919 adult residents in Gyodong-myeon and 313 adults in Samsan-myeon were collected and checked for IgG antibody titers, which showed 14.5% (133 sera) and 19.8% (62 sera) positive rates, respectively. In 2011, sera of 955 adults in Gyodong-myeon and 341 adults in Samsan-myeon were examined, which showed an increase of positive rates to 23.8% (227 sera) and 31.7% (108 sera), respectively. Totally, the seroprevalence of the first year was 15.8% and it increased rapidly to 25.8% in the second year. The positive rates of both sexes increased simultaneously with the significant ratio of males to females by 1.7-2.2 fold (P<0.05). In both myeons, 661 sera were collected every year and showed changes in optical density (OD) in 177 sera; newly found as positives in 73 persons (11.0%), negative conversion in 10 persons (1.5%), and maintained or increased in 94 persons (14.2%). This rapid increase in the prevalence of toxoplasmosis in Gangwha islands may be due to in part peculiar changes in the toxoplasmic environment of the islands and presumably the consumption of the pork bred domestically within the islands or imported from high endemic nations. It is necessary to find out symptomatic toxoplasmic patients and confirm the risk factors for further infection in the islands of Gangwha-gun.

Gender Differences in Susceptibility to Smoking among Patients with Lung Cancer

BACKGROUND/AIMS: To determine whether female smokers are more or less susceptible to the detrimental pulmonary-function effects of smoking when compared to male smokers among patients with lung cancer. METHODS: Pack-years and pulmonary function indices were compared between 1,594 men and women with lung cancer ifferences in individual susceptibility to smoking were estimated using a susceptibility index formula. RESULTS: Of the patients, 959 (92.8%) men and 74 (7.2%) women were current smokers. Common histological types of lung cancer were squamous cell carcinoma, adenocarcinoma, and small cell carcinoma, among others. Women had a lower number of pack-years, forced expiratory volume in 1 second (FEV1, liters), forced vital capacity (FVC, liters), and total lung capacity (TLC, liters) compared to those of men (25.0 +/- 19.2 vs. 42.9 +/- 21.7 for pack-years; 1.4 +/- 0.5 vs. 2.0 +/- 0.6 for FEV1; 3.0 +/- 0.7 vs. 2.0 +/- 0.6 for FVC; 4.5 +/- 0.8 vs. 5.7 +/- 1.0 for TLC; all p < 0.001). The susceptibility index for women was significantly higher compared to that of men (1.1 +/- 4.1 vs. 0.7 +/- 1.1; p = 0.001). A significant inverse association was shown between the susceptibility index and TLC and FVC (r = -0.200 for TLC, -0.273 for FVC; all p < 0.001). CONCLUSIONS: The results suggest that the detrimental effects of smoking on pulmonary function are greater in women, as compared to those in men, among patients with lung cancer.

Serum TSH Level in Healthy Koreans and the Association of TSH with Serum Lipid Concentration and Metabolic Syndrome

BACKGROUND/AIMS: The proper treatment of subclinical hypothyroidism and the normal range of serum thyroid stimulating hormone (TSH) concentration are intensely debated. However, few reports have investigated TSH concentrations in Asian ethnic groups. Therefore, the present study was designed to define the TSH reference range in a Korean population and to investigate the metabolic significance of TSH concentration. METHODS: We enrolled patients who underwent medical examination at the CHA Bundang Medical Center. Anthropometric data were evaluated, and serum TSH, free T4, and lipid profiles were assayed. RESULTS: A total of 7,270 subjects were included. Mean TSH concentration of the study population was 1.82 +/- 0.95 mU/L, and we observed a sex-related difference in TSH concentration (male, 1.67 +/- 0.87 mU/L; female, 2.02 +/- 1.01 mU/L; p < 0.01). When the 2.5 and 97.5 percentiles were calculated, 95% TSH reference limits were 0.52-4.29 mU/L. TSH concentration was higher in elderly subjects, during winter, in postmenopausal women, and in obese males. Moreover, TSH showed significantly positive correlations with serum total cholesterol, triglyceride, and low density lipoprotein cholesterol regardless of sex, age, season, obesity, or menopausal status (all p < 0.01). Finally, TSH concentration was positively related to the prevalence of metabolic syndrome. CONCLUSIONS: We demonstrated the association between TSH concentration within the normal reference range and serum lipid levels. TSH concentration varies according to sex, age, season, and body mass index (only in males). Moreover, high normal TSH levels were significantly associated with an increased prevalence of metabolic syndrome, which may be of importance when evaluating subjects with high normal TSH concentration.

Causes of Different Estimates of the Prevalence of Metabolic Syndrome in Korea

BACKGROUND/AIMS: Reports of the prevalence of and trends in metabolic syndrome in Korea have been inconsistent. Thus, we investigated the reasons underlying these inconsistencies. METHODS: We estimated the prevalence of metabolic syndrome using different diagnostic criteria, exclusion criteria, and sampling weights among 5,509 respondents, aged 20-79, who participated in the 2001 Korean National Health and Nutrition Examination Surveys (KNHANES). Trends in metabolic syndrome were assessed by examining the 1998 (n = 6,747), 2001 (n = 4,337), and 2005 (n = 5,139) KNHANES. RESULTS: The estimated prevalence of metabolic syndrome in 2001 ranged from 1.6 to 29.6% in males and from 10.1 to 32.8% in females, depending on the diagnostic criteria used. The exclusion criteria and sampling weights did not significantly affect the prevalence estimates. The prevalence of metabolic syndrome first significantly increased and then decreased between 1998, 2001, and 2005 in males (26.2, 29.6, and 27.2%, respectively) and females (29.2, 32.8, and 24.7%, respectively). Among the individual metabolic variables, triglyceride levels in 2001 were significantly higher than in 1998 and 2005, whereas other variables remained relatively constant during the same period. The exceptionally high triglyceride levels in 2001 might have contributed to the increased prevalence of metabolic syndrome between 1998 and 2001. CONCLUSIONS: Different diagnostic criteria for metabolic syndrome represent a major cause of the inconsistent estimates of prevalence, and the absence of standardized laboratory methods might have affected the trend estimates.