Subclinical hypothyroidism (SCH), characterized by elevated serum thyroid-stimulating hormone (TSH) levels and normal free thyroxine levels, usually presents without symptoms, and is often discovered incidentally during routine blood test. The Task Force of the Korean Thyroid Association Committee of Clinical Practice Guidelines has established a guideline to evaluate and manage SCH; the guideline emphasizes the implementation of diagnostic criteria based on the TSH reference range for Koreans and focuses on the proven health benefits of levothyroxine (LT4) treatment. Based on the Korea National Health and Nutrition Examination Survey (2013-2015), serum TSH level of 6.8 mIU/L is considered the reference value for SCH. SCH can be categorized as mild (TSH 6.8-10.0 mIU/L) or severe (TSH ＞10.0 mIU/L), and patients are classified as adults (age ＜70 years) or elderly patients (age ≥70years) depending on the health effects of LT4 treatment. An initial increase in serum TSH levels should be reassessed with a subsequent measurement, along with the thyroid peroxidase antibody test, preferably 2-3 months after the initial evaluation. Usually, LT4 treatment is not recommended for mild SCH in adults; however, treatment is necessary for severe SCH in patients with underlying coronary artery disease or heart failure and can be considered for coexisting dyslipidemia. LT4 treatment is not recommended for mild or even severe SCH in elderly patients, in general. Patients with SCH who receive LT4 treatment, the LT4 dosage should be personalized, and serum TSH levels should be monitored to ensure optimal LT4 dosage (dosage that is neither excessive nor insufficient). Patients with SCH who do not receive LT4 treatment require periodic follow-up at appropriate testing intervals determined by disease severity. The guideline also provides several educational points applicable in clinical settings.

BACKGROUND: Iodine is an intrinsic element of thyroid hormone, which is essential for childhood growth and development. The Ideal Breast Milk (IBM) cohort study aims to evaluate the effects of maternal iodine status during pregnancy and lactation on maternal thyroid function, offspring growth and development, and offspring thyroid function. METHODS: The IBM cohort study recruited pregnant women from Seoul National University Hospital between June 2016 and August 2017, followed by enrollment of their offspring after delivery. For the maternal participants, iodine status is evaluated by urinary iodine concentration (UIC) and dietary records in the third trimester and at 3 to 4 weeks and 12 to 15 months postpartum. For the child participants, cord blood sampling and UIC measurements are performed at birth. At 3 to 4 weeks of age, UIC and breastmilk iodine concentrations are measured. At 12 to 15 months of age, growth and development are assessed and measurements of UIC, a thyroid function test, and ultrasonography are performed. RESULTS: A total of 198 pregnant women in their third trimester were recruited. Their mean age was 35.1±3.5 years, and 78 (39.4%) of them were pregnant with twins. Thirty-three (16.7%) of them had a previous history of thyroid disease. CONCLUSION: Korea is an iodine-replete area. In particular, lactating women in Korea are commonly exposed to excess iodine due to the traditional practice of consuming brown seaweed soup postpartum. The study of the IBM cohort is expected to contribute to developing guidelines for optimal iodine nutrition in pregnant or lactating women.
Breast* ; Child ; Cohort Studies* ; Cordocentesis ; Diet Records ; Female ; Growth and Development* ; Humans ; Infant ; Iodine* ; Korea ; Lactation* ; Milk, Human* ; Parturition ; Postpartum Period ; Pregnancy Trimester, Third ; Pregnancy* ; Pregnant Women ; Prospective Studies* ; Seaweed ; Seoul ; Thyroid Diseases ; Thyroid Function Tests ; Thyroid Gland* ; Twins ; Ultrasonography

PURPOSE: This study evaluated the relationship of living near to main roads to allergic diseases, airway hyperresponsiveness (AHR), allergic sensitization, and lung function in Korean children. METHODS: A total of 5,443 children aged 6-14 years from 33 elementary schools in 10 cities during 2005-2006 were included in a baseline survey of the Children's Health and Environmental Research. We assessed association of traffic-related air pollution (TAP) exposure with the distance to the nearest main road, total road length of main roads and the proportion of the main road area within the 200-m home area. RESULTS: Positive exposure-response relationships were found between the length of the main road within the 200-m home area and lifetime wheeze (adjusted prevalence ratio [PR] for comparison of the longest to the shortest length categories=1.24; 95% CIs, 1.04-1.47; P for trend=0.022) and diagnosed asthma (PR=1.42; 95% CIs, 1.08-1.86; P for trend=0.011). Living less than 75 m from the main road was significantly associated with lifetime allergic rhinitis (AR), past-year AR symptoms, diagnosed AR, and treated AR. The distance to the main road (P for trend=0.001), the length of the main road (P for trend=0.041), and the proportion of the main road area (P for trend=0.006) had an exposure-response relationship with allergic sensitization. A strong inverse association was observed between residential proximity to the main load and lung function, especially FEV1, FEV1/FVC, and FEF25-75. The length of the main road and the proportion of the main road area were associated with reduced FEV1 in schoolchildren. CONCLUSIONS: The results of this study suggest that exposure to traffic-related air pollution may be associated with increased risk of asthma, AR, and allergic sensitization, and with reduced lung function in schoolchildren.
Air Pollution* ; Asthma ; Bronchial Hyperreactivity ; Child ; Surveys and Questionnaires ; Humans ; Lung ; Prevalence ; Respiratory Function Tests ; Rhinitis

OBJECTIVES: The purpose of the present study was to identify the association between presenteeism and long working hours, shiftwork, and occupational stress using representative national survey data on Korean workers. METHODS: We analyzed data from the second Korean Working Conditions Survey (KWCS), which was conducted in 2010, in which a total of 6,220 wage workers were analyzed. The study population included the economically active population aged above 15 years, and living in the Republic of Korea. We used the chi-squared test and multivariate logistic regression to test the statistical association between presenteeism and working hours, shiftwork, and occupational stress. RESULTS: Approximately 19% of the workers experienced presenteeism during the previous 12 months. Women had higher rates of presenteeism than men. We found a statistically significant dose-response relationship between working hours and presenteeism. Shift workers had a slightly higher rate of presenteeism than non-shift workers, but the difference was not statistically significant. Occupational stress, such as high job demand, lack of rewards, and inadequate social support, had a significant association with presenteeism. CONCLUSIONS: The present study suggests that long working hours and occupational stress are significantly related to presenteeism.
Female ; Humans ; Logistic Models ; Male ; Republic of Korea ; Reward ; Salaries and Fringe Benefits*

BACKGROUND: Hypoxemia during one-lung ventilation (OLV) remains a major concern. The present study compared the effect of alveolar recruitment strategy (ARS) on arterial oxygenation during OLV at varying tidal volumes (Vt) with or without positive end-expiratory pressure (PEEP). METHODS: In total, 120 patients undergoing wedge resection by video assisted thoracostomy were randomized into four groups comprising 30 patients each: those administered a 10 ml/kg tidal volume with or without preemptive ARS (Group H and Group H-ARS, respectively) and those administered a 6 ml/kg tidal volume and a 8 cmH2O PEEP with or without preemptive ARS (Group L and Group L-ARS, respectively). ARS was performed using pressure-controlled ventilation with a 40 cmH2O plateau airway pressure and a 15 cmH2O PEEP for at least 10 breaths until OLV began. RESULTS: Preemptive ARS significantly improved the PaO2/FiO2 ratio compared to the groups that did not receive ARS (P < 0.05). The H-ARS group showed a highest PaO2/FiO2 ratio during OLV, the L-ARS and H groups showed similarly improved arterial oxygenation, which was significantly higher than in group L (P < 0.05). The plateau airway pressure in group H-ARS was significantly higher than in group L-ARS (P < 0.05). CONCLUSIONS: Preemptive ARS can improve arterial oxygenation during OLV. Furthermore, a 6 ml/kg tidal volume combined with 8 cmH2O PEEP after preemptive ARS may reduce the risk of pulmonary injury caused by high tidal volume during one-lung ventilation in patients with normal pulmonary function.
Anoxia ; Humans ; Lung Injury ; One-Lung Ventilation* ; Oxygen* ; Positive-Pressure Respiration ; Respiratory Function Tests* ; Thoracostomy ; Tidal Volume* ; Ventilation

BACKGROUND: Brother of the regulator of imprinted sites (BORIS) is a putative new oncogene that is classified as a cancer germline gene; however, its role in the development of cancer is unclear. This study investigated the expression of BORIS in lung cancer and its clinical implications. METHODS: The expression of BORIS messenger ribonucleic acid (mRNA) in the sputum of 100 patients with lung cancer (50 with squamous cell carcinoma, 36 with adenocarcinoma, and 14 with small-cell carcinoma) was evaluated by reverse transcription polymerase chain reaction. RESULTS: The overall expression rate of BORIS in patients with lung cancer was 36.0%: 19 of 50 squamous cell carcinomas (38.0%), 13 of 36 adenocarcinomas (36.1%), and 4 of 14 (28.6%) small-cell carcinomas. There was no significant difference in the BORIS expression according to age, gender, or histologic type. However, the mRNA expression of BORIS was significantly related to the pathologic cancer stage (p=0.004) and lymph node metastasis (p=0.001). The expression of the melanoma antigen gene family A1-6 was not associated with the expression of BORIS. CONCLUSION: Our results suggest that the expression of BORIS might be a negative prognostic factor in lung cancers and implicate BORIS as a molecular target for immunotherapy.
Adenocarcinoma ; Carcinoma, Squamous Cell ; Humans ; Immunotherapy ; Lung Neoplasms* ; Lymph Nodes ; Melanoma ; Neoplasm Metastasis ; Oncogenes ; Polymerase Chain Reaction ; Reverse Transcription ; RNA ; RNA, Messenger ; Siblings* ; Sputum*

Familial isolated primary hyperparathyroidism(FIPH) is associated with multiple endocrine neoplasia type 1 (MEN1) syndrome, primary hyperparathyroidism accompanied by jaw-tumor syndrome, and familial hypocalciuric hypercalcemia. FIPH may be an early stage of MEN1 or an allelic variant of MEN1. Thymic carcinoid tumor is a rare tumor in MEN1 syndrome. Here, the authors report the case of a 40-year-old man diagnosed with recurrent thymic carcinoid tumor and FIPH. Both the patient and his elder sister had been previously diagnosed to have FIPH with a novel frameshift mutation in the MEN1 gene. Initially, the patient underwent thymectomy because of an incidental finding of a mediastinal mass in his chest X-ray, and had remained asymptomatic over the following 4 years. Pancreas computed tomography conducted to evaluate MEN1 syndrome revealed anterior and middle mediastinal masses, and resultantly, massive mass excision was performed. Histological findings disclosed atypical carcinoids with infiltrative margins. In view of the thymic carcinoid tumor relapse that occurred in this patient, the authors recommend that regular pancreas and pituitary imaging studies be conducted for FIPH associated with a MEN1 gene mutation.
Adult ; Carcinoid Tumor* ; Frameshift Mutation ; Humans ; Hypercalcemia ; Hyperparathyroidism ; Hyperparathyroidism, Primary* ; Incidental Findings ; Multiple Endocrine Neoplasia Type 1 ; Pancreas ; Recurrence ; Siblings ; Thorax ; Thymectomy

BACKGROUND: It has been known that positive end-expiratory pressure (PEEP) increases the vasoconstriction threshold by baroreceptor unloading. We compared the effect on the thermoregulatory responses according to anesthetic techniques between an inhalation anesthesia with desflurane and a total intravenous anesthesia (TIVA) with propofol and reminfentanil when PEEP was applied in patients undergoing tympanoplasty. METHODS: Forty-six patients with a scheduled tympanoplasty were enrolled and the patients were divided in two study groups. Desflurane was used as an inhalation anesthetic in group 1 (n = 22), while TIVA with propofol and remifentanil was used in group 2 (n = 24). PEEP was applied by 5 cmH2O in both groups and an ambient temperature was maintained at 22-24degrees C during surgery. The core temperature and the difference of skin temperature between forearm and fingertip were monitored for about 180 minutes before and after the induction of general anesthesia. RESULTS: The final core temperature was significantly higher in group 2 (35.4 +/- 0.7degrees C) than in group 1 (34.9 +/- 0.5degrees C). Peripheral thermoregulatory vasoconstriction was found in 5 subjects (23%) in group 1 and in 21 subjects (88%) in group 2. The time taken for reaching the thermoregulatory vasoconstriction threshold was 151.4 +/- 19.7 minutes in group 1 and 88.9 +/- 14.4 minutes in group 2. CONCLUSIONS: When PEEP will be applied, anesthesia with TIVA may have more advantages in core temperature preservation than an inhalation anesthesia with desflurane.
Anesthesia ; Anesthesia, General ; Anesthesia, Inhalation* ; Anesthesia, Intravenous ; Body Temperature Regulation ; Forearm ; Humans ; Inhalation ; Positive-Pressure Respiration ; Pressoreceptors ; Propofol ; Skin Temperature ; Tympanoplasty* ; Vasoconstriction

BACKGROUND: Rocuronium has been well known to produce withdrawal response in 50-80% patients when administered intravenously. Several drugs are administered prior injection of rocuronium to prevent the withdrawal response. We compared the preventive effect of lidocaine, ketamine, and remifentanil on the withdrawal response of rocuronium. METHODS: A total of 120 patients undergoing various elective surgeries were enrolled. Patients were allocated into 4 groups according to the pretreatment drugs (Group N, normal saline; Groups L, lidocaine 40 mg; Group K, ketamine 0.5 mg/kg; Group R, remifentanil 1 microg/kg). Patients received drugs prepared by dilution to 3 ml volume before injection of rocuronium. Withdrawal responses after injection of rocuronium were graded on a 4-point scale. Hemodynamic changes were observed before and after administration of pretreatment drugs and after endotracheal intubation. RESULTS: Incidence of withdrawal response was significantly lower in group L (20%), group K (30%), and group R (0%), than group N (87%). Severe withdrawal response was observed in 5 of the 30 patients (17%) in group L, and in 9 of the 30 patients (30%) in group K. There was no severe withdrawal response in group R. Mean blood pressure and heart rate were significantly decreased in group R compared to other groups. CONCLUSIONS: It seems that remifentanil (1 microg/kg intravenously) was the strongest and most effective in prevention of withdrawal response after rocuronium injection among the 3 drugs.
Blood Pressure ; Heart Rate ; Hemodynamics ; Humans ; Incidence ; Intubation, Intratracheal ; Ketamine* ; Lidocaine*