PURPOSE: Asthma is a heterogeneous disease that responds to medications to varying degrees. Cluster analyses have identified several phenotypes and variables related to fixed airway obstruction; however, few longitudinal studies of lung function have been performed on adult asthmatics. We investigated clinical, demographic, and inflammatory factors related to persistent airflow limitation based on lung function trajectories over 1 year. METHODS: Serial post-bronchodilator forced expiratory volume (FEV) 1% values were obtained from 1,679 asthmatics who were followed up every 3 months for 1 year. First, a hierarchical cluster analysis was performed using Ward's method to generate a dendrogram for the optimum number of clusters using the complete post-FEV1 sets from 448 subjects. Then, a trajectory cluster analysis of serial post-FEV1 sets was performed using the k-means clustering for the longitudinal data trajectory method. Next, trajectory clustering for the serial post-FEV1 sets of a total of 1,679 asthmatics was performed after imputation of missing post-FEV1 values using regression methods. RESULTS: Trajectories 1 and 2 were associated with normal lung function during the study period, and trajectory 3 was associated with a reversal to normal of the moderately decreased baseline FEV1 within 3 months. Trajectories 4 and 5 were associated with severe asthma with a marked reduction in baseline FEV1. However, the FEV1 associated with trajectory 4 was increased at 3 months, whereas the FEV1 associated with trajectory 5 was persistently disturbed over 1 year. Compared with trajectory 4, trajectory 5 was associated with older asthmatics with less atopy, a lower immunoglobulin E (IgE) level, sputum neutrophilia and higher dosages of oral steroids. In contrast, trajectory 4 was associated with higher sputum and blood eosinophil counts and more frequent exacerbations. CONCLUSIONS: Trajectory clustering analysis of FEV1 identified 5 distinct types, representing well-preserved to severely decreased FEV1. Persistent airflow obstruction may be related to non-atopy, a low IgE level, and older age accompanied by neutrophilic inflammation and low baseline FEV1 levels.
Adult* ; Airway Obstruction ; Asthma* ; Disease Progression ; Eosinophils ; Forced Expiratory Volume ; Humans ; Immunoglobulin E ; Immunoglobulins ; Inflammation ; Longitudinal Studies ; Lung* ; Methods ; Neutrophils ; Phenotype ; Sputum ; Steroids

BACKGROUND AND OBJECTIVES: The level of thyroid-stimulating hormone (TSH)-stimulated thyroglobulin (Tg) after thyroid hormone withdrawal (THW) is the most sensitive marker for detecting recurrence of differentiated thyroid cancer (DTC). In DTC, Tg production is regulated by TSH; however, TSH values after THW are never identical, even in the same patient. The objective of this study was to evaluate the influence of TSH on Tg levels after THW. MATERIALS AND METHODS: TSH and Tg concentrations were measured twice at 2 and 3 weeks after THW in 309 patients with DTC. TSH and Tg levels at these time points were compared. The percent change in TSH (ΔTSH) and change in Tg level (%ΔTg) from 2 to 3 weeks after THW were calculated, and Pearson's correlation coefficients were calculated to determine whether ΔTSH could affect %ΔTg. Tg cutoff value for diagnostic imaging was 2 ng/mL. RESULTS: The TSH and Tg values at 3 weeks were significantly higher than those at 2 weeks after THW. Tg values increased significantly to >2 ng/mL after 1 week in 38.5% of the patients with Tg values of 0.2-2 ng/mL at 2 weeks after THW. In patients with Tg values ≥2 ng/mL at 2 weeks after THW, Tg values increased significantly after an additional week of THW. ΔTSH correlated significantly with %ΔTg. CONCLUSION: TSH values differed according to time after THW, and Tg values differed significantly according to TSH values. Therefore, TSH values should be considered carefully when interpreting the meaning of Tg levels in patients with DTC.
Diagnostic Imaging ; Humans ; Recurrence ; Thyroglobulin* ; Thyroid Function Tests ; Thyroid Gland* ; Thyroid Neoplasms* ; Thyrotropin*

BACKGROUND AND OBJECTIVES: The aim of this study was to determine whether pathologically proven central or lateral lymph node (LN) metastasis (pN1a or pN1b) could affect ablation success and recurrence after high-dose radioactive iodine (RAI) ablation. We also sought to identify the risk factors for long-term recurrence in patients with papillary thyroid carcinoma (PTC). MATERIALS AND METHODS: A total of 277 patients with pN1 disease who had undergone high-dose RAI ablation (5.55 GBq) between 2000 and 2006 were included in this retrospective study. We compared the ablation success rate and the recurrence rate between patients with pN1a and pN1b disease. Univariate and multivariate analyses were performed to identify the risk factors for recurrence. RESULTS: The median duration of follow-up was 10.2 years. The overall ablation success rate was 64%, and the ablation success rate in the pN1b group (49%) was lower than in the pN1a group (74%). The overall recurrence rate was 23%, and the recurrence rate in the pN1b group (30%) was higher than in pN1a group (18%). A higher ratio of metastatic LNs, a higher level of pre-ablation thyroglobulin, and ablation failure were significant risk factors for recurrence by multivariate analysis. CONCLUSION: Patients with pN1b disease experienced a lower ablation success rate and a higher recurrence rate than patients with pN1a disease. However, a higher ratio of metastatic LNs, a higher level of pre-ablation thyroglobulin, and ablation failure were stronger risk factors than the pathological N stage for long term recurrence in patients with node-positive PTC.
Follow-Up Studies ; Humans ; Iodine ; Lymph Nodes ; Multivariate Analysis ; Neoplasm Metastasis* ; Recurrence ; Retrospective Studies ; Risk Factors ; Thyroglobulin ; Thyroid Neoplasms

BACKGROUND AND OBJECTIVES: The aim of this study was to determine whether pathologically proven central or lateral lymph node (LN) metastasis (pN1a or pN1b) could affect ablation success and recurrence after high-dose radioactive iodine (RAI) ablation. We also sought to identify the risk factors for long-term recurrence in patients with papillary thyroid carcinoma (PTC). MATERIALS AND METHODS: A total of 277 patients with pN1 disease who had undergone high-dose RAI ablation (5.55 GBq) between 2000 and 2006 were included in this retrospective study. We compared the ablation success rate and the recurrence rate between patients with pN1a and pN1b disease. Univariate and multivariate analyses were performed to identify the risk factors for recurrence. RESULTS: The median duration of follow-up was 10.2 years. The overall ablation success rate was 64%, and the ablation success rate in the pN1b group (49%) was lower than in the pN1a group (74%). The overall recurrence rate was 23%, and the recurrence rate in the pN1b group (30%) was higher than in pN1a group (18%). A higher ratio of metastatic LNs, a higher level of pre-ablation thyroglobulin, and ablation failure were significant risk factors for recurrence by multivariate analysis. CONCLUSION: Patients with pN1b disease experienced a lower ablation success rate and a higher recurrence rate than patients with pN1a disease. However, a higher ratio of metastatic LNs, a higher level of pre-ablation thyroglobulin, and ablation failure were stronger risk factors than the pathological N stage for long term recurrence in patients with node-positive PTC.
Follow-Up Studies ; Humans ; Iodine ; Lymph Nodes ; Multivariate Analysis ; Neoplasm Metastasis* ; Recurrence ; Retrospective Studies ; Risk Factors ; Thyroglobulin ; Thyroid Neoplasms

BACKGROUND/AIMS: The relationship between Crohn's disease and gallstones is established. However, the prevalence and risk factors for gallstones in patients with ulcerative colitis (UC) are not yet well understood. The aim of this study was to evaluate the prevalence and risk factors of gallstones in patients with UC. METHODS: This study was a retrospective single center study. A total of 87 patients with UC and 261 healthy controls were enrolled. Age, sex, and body mass index were matched. To investigate risk factors, the extent of UC, duration of disease, number of hospital admissions, and number of steroid treatments in patients with UC were evaluated. RESULTS: The prevalence of gallstones in patients with UC was 13.8%, whereas that in healthy controls was only 3.1% (P<0.001). For patients with UC, patients > or =50 years of age had a 3.6-times higher risk of gallstones compared to that in those <50 years of age, and the difference was statistically significant (odds ratio, 3.60; confidence interval, 1.03-12.61) in univariate analysis. There were no statistically significant disease-related risk factors for gallstones in UC patients. CONCLUSIONS: This is the first study of gallstone prevalence in Korean UC patients. In this study, patients with UC had a higher prevalence of gallstones compared to that in well-matched healthy controls. Age seemed to be a possible risk factor, and more studies are needed. Further prospective, large-scale studies will be required to confirm the risk factors for gallstones in UC patients.
Asymptomatic Diseases ; Body Mass Index ; Colitis, Ulcerative* ; Crohn Disease ; Gallstones* ; Humans ; Prevalence ; Retrospective Studies ; Risk Factors

BACKGROUND/AIMS: The relationship between Crohn's disease and gallstones is established. However, the prevalence and risk factors for gallstones in patients with ulcerative colitis (UC) are not yet well understood. The aim of this study was to evaluate the prevalence and risk factors of gallstones in patients with UC. METHODS: This study was a retrospective single center study. A total of 87 patients with UC and 261 healthy controls were enrolled. Age, sex, and body mass index were matched. To investigate risk factors, the extent of UC, duration of disease, number of hospital admissions, and number of steroid treatments in patients with UC were evaluated. RESULTS: The prevalence of gallstones in patients with UC was 13.8%, whereas that in healthy controls was only 3.1% (P<0.001). For patients with UC, patients > or =50 years of age had a 3.6-times higher risk of gallstones compared to that in those <50 years of age, and the difference was statistically significant (odds ratio, 3.60; confidence interval, 1.03-12.61) in univariate analysis. There were no statistically significant disease-related risk factors for gallstones in UC patients. CONCLUSIONS: This is the first study of gallstone prevalence in Korean UC patients. In this study, patients with UC had a higher prevalence of gallstones compared to that in well-matched healthy controls. Age seemed to be a possible risk factor, and more studies are needed. Further prospective, large-scale studies will be required to confirm the risk factors for gallstones in UC patients.
Asymptomatic Diseases ; Body Mass Index ; Colitis, Ulcerative* ; Crohn Disease ; Gallstones* ; Humans ; Prevalence ; Retrospective Studies ; Risk Factors

PURPOSE: Vitamin D deficiency (VDD) is widely spread and on the increase throughout the world. Although vitamin D is essential for skeletal mineralization, VDD or vitamin D insufficiency (VDI) has been associated with nonskeletal disorders including cardiovascular disease, cancer, allergic disease and skin disease. However, a few reports showed the association of vitamin D and drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome. Thereafter, we evaluated the association between vitamin D and DRESS syndrome. METHODS: We conducted a retrospective study on 45 patients with DRESS syndrome. Four hundred and ninty-eight healthy people who visited the health screening center were enrolled in the study as a control group. We investigated the clinical characteristics, the causative drugs and treatments in the patients with DRESS syndrome, and also analyzed the associations with serum 25-hydroxyvitamin D (25(OH)D3). RESULTS: Forty-four patients (97.8%) had low serum vitamin D levels; 21 patients were VDD (serum 25(OH)D3 <10 ng/mL), and 23 patients were VDI (serum 25(OH)D3 10 to 30 ng/mL). There were no significant differences in clinical parameters between two groups. Serum 25(OH)D3 level of the study patients was significantly lower that of the controls (12.3+/-9.6 ng/mL vs. 17.3+/-5.5 ng/mL, P<0.001). Serum 25(OH)D3 level showed a significant negative correlation with admission days (r=-0.377, P=0.011). CONCLUSION: The majority of the patients with DRESS syndrome showed low vitamin D levels. Serum 25(OH)D3 was inversely correlated with admission days.
Cardiovascular Diseases ; Drug Hypersensitivity ; Eosinophilia ; Humans ; Mass Screening ; Retrospective Studies ; Skin Diseases ; Vitamin D ; Vitamin D Deficiency ; Vitamins

There are many studies on the prevalence, clinical characteristics, and economic burden of diabetes across the past four decades in Korea. Nonetheless, there is a dearth of nationwide study regarding diabetes encompassing all age group. Eight years ago, the Committee on the Epidemiology of Diabetes Mellitus of Korean Diabetes Association collaborated with Health Insurance Review & Assessment Service to evaluate the status of diabetes care and characteristics in diabetic patients in Korea. In 2007, the collaborative task force team published a comprehensive survey titled "Diabetes in Korea 2007." In this review, we reappraise the diabetic epidemics from the joint report and suggest further studies that are needed to be investigated in the future.
Advisory Committees ; Diabetes Mellitus ; Diabetes Mellitus, Type 2 ; Humans ; Insurance, Health ; Joints ; Korea ; Prevalence

Hydroxyapatite is commonly used as a filler to replace amputated bone or as a coating to promote bone ingrowth into prosthetic implants. Many modern implants, such as hip replacements and dental implants, are coated with hydroxyapatite. We report a patient with occupational asthma due to hydroxyapatite, proven by a specific inhalation challenge, who experienced an early asthmatic reaction after exposure to hydroxyapatite, without increased airway responsiveness to methacholine despite an increased eosinophil count in the peripheral blood. A 38-year-old male dental implant worker visited our allergy department for the evaluation of occupational asthma. He had treated dental implant titanium surfaces with hydroxyapatite for 1.5 years. One year after starting his employment, he noticed symptoms of rhinorrhea, paroxysmal cough, and chest tightness. His symptoms were aggravated during and shortly after work and subsided several hours after work. When he stopped working for 2 months because of his chest symptoms, he became asymptomatic. After restarting his work, his symptoms reappeared and were aggravated. A methacholine bronchial challenge test had a negative response. The following day, a specific bronchial provocation test with wheat powder was negative. On the third day, a specific bronchial provocation test with hydroxyapatite powder produced an early asthmatic response. On the fourth day, a methacholine bronchial challenge test was negative. Further studies are needed to evaluate the exact pathogenetic mechanism of hydroxyapatite-induced occupational asthma.
Adult ; Asthma ; Asthma, Occupational ; Bronchial Provocation Tests ; Cough ; Dental Implants ; Durapatite ; Employment ; Eosinophils ; Hip ; Humans ; Hypersensitivity ; Inhalation ; Male ; Methacholine Chloride ; Occupations ; Thorax ; Titanium ; Triticum

BACKGROUND/AIMS: Stomach cancer can be easily diagnosed via endoscopy, but also possible to be missed. The aim of this study was to investigate the clinical and endoscopic characteristics of advanced gastric cancers that were not diagnosed based on endoscopic examination. METHODS: We evaluated patients who had newly diagnosed advanced gastric cancer that was undetected via endoscopy within the last six months. RESULTS: Sixteen patients were included in this study. The locations of the cancers were the cardia in six cases, the greater curvature side of the body in eight cases and the antrum in two cases. The histological findings were tubular type adenocarcinoma in 11 cases, with ten cases of moderately to poorly differentiated adenocarcinoma and five cases of signet ring cell type adenocarcinoma. CONCLUSIONS: Even advanced gastric cancer lesions may not be detected during endoscopy. If a patient continues to complain of upper gastrointestinal symptoms, even though endoscopy does not find abnormal findings, repeated endoscopy and/or additional diagnostic studies should be considered.
Adenocarcinoma/*diagnosis/pathology ; Adult ; Aged ; Cardia/pathology ; Diagnostic Errors ; Female ; Gastroscopy ; Humans ; Male ; Middle Aged ; Prognosis ; Pyloric Antrum/pathology ; Stomach Neoplasms/*diagnosis/pathology