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Objective: To compare thyroid cancer incidence rates and trends between Korean, non-Korean Asian, and non-Hispanic White populations in the United States, and between the US Korean population and the South Korean population., Method: Population-based analysis of cancer incidence data. Cases of thyroid cancer diagnosed during 1999-2014 from the Korean Central Cancer Registry (KCCR) and the Surveillance, Epidemiology, and End Results (SEER) 9 detailed Asian/Pacific Islander subgroup incidence and population dataset were included. Incidence rates were obtained from the datasets, and annual percent change (APC) of the incidence rates was calculated using Joinpoint regression analysis., Results: Thyroid cancer incidence rate for 1999-2014 was significantly higher for South Korea (48.05 [95% CI 47.89-48.22] per 100,000 person-years) than for the US Korean population (11.12 [95% CI 10.49-11.78] per 100,000 person-years), which was slightly higher than the Non-Korean Asian population (10.23 [95% CI 10.02-10.43] per 100,000 person-years), and slightly lower than the Non-Hispanic White population (12.78 [95% CI 12.69-12.87] per 100,000 person-years). Incidence rates in South Korea increased dramatically (average APC 17.9, 95% CI 16.0-19.9), significantly higher than the US Korean population (average APC 5.0, 95% CI 3.1-6.8), which was similar to the non-Korean Asian (average APC 2.5, 95% CI 0.9-4.2) and the non-Hispanic White (average APC 5.1, 95% CI 4.7-5.6) populations., Conclusions: South Korea's high thyroid cancer incidence rates cannot be attributed to genetic factors, but are likely due to health care system factors., Level of Evidence: 3 Laryngoscope, 134:4156-4160, 2024., (© 2024 The American Laryngological, Rhinological and Otological Society, Inc.)

We aimed to investigate the associations of previous influenza/URI with the susceptibility of COVID-19 patients compared to that of non-COVID-19 participants. A nationwide COVID-19 cohort database was collected by the Korea National Health Insurance Corporation. A total of 8,070 COVID-19 patients (1 January 2020 through 4 June 2020) were matched with 32,280 control participants. Severe COVID-19 morbidity was defined based on the treatment histories of the intensive care unit, invasive ventilation, and extracorporeal membrane oxygenation and death. The susceptibility/morbidity/mortality associated with prior histories of 1-14, 1-30, 1-90, 15-45, 15-90, and 31-90 days before COVID-19 onset were analyzed using conditional/unconditional logistic regression. Prior influenza infection was related to increased susceptibility to COVID-19 (adjusted odds ratio [95% confidence interval] = 3.07 [1.61-5.85] for 1-14 days and 1.91 [1.54-2.37] for 1-90 days). Prior URI was also associated with increased susceptibility to COVID-19 (6.95 [6.38-7.58] for 1-14 days, 4.99 [4.64-5.37] for 1-30 days, and 2.70 [2.55-2.86] for 1-90 days). COVID-19 morbidity was positively associated with influenza (3.64 [1.55-9.21] and 3.59 [1.42-9.05]) and URI (1.40 [1.11-1.78] and 1.28 [1.02-1.61]) at 1-14 days and 1-30 days, respectively. Overall, previous influenza/URI did not show an association with COVID-19 mortality. Previous influenza/URI histories were associated with increased COVID-19 susceptibility and morbidity. Our findings indicate why controlling influenza/URI is important during the COVID-19 pandemic., (© 2021. The Author(s).)

A nationwide survey of chigger mites causing scrub typhus and an investigation of epidemiologic factors for chigger mites was conducted at 16 localities in 8 provinces in Korea during autumn 2009, 2012, and 2013. A total of 233 Apodemus agrarius were captured, and all were infested with chigger mites. The chigger index was highest in Chungcheongbuk-do in 2009 (358.3) and 2012 (290.1) and Chungcheongnam-do in 2013 (294.4). The predominant chigger mite species was Leptotrombidium pallidum in the northern and central parts and L. scutellare in the southern and western parts, Korea. L. pallidum was not found in Jellanam-do and Gyeongsangnam-do and the distribution of L. scutellare had been expanded in the northern parts of Korea. The chigger index of L. pallidum was positively correlated with temperature and negatively correlated with humidity. The incidence of scrub typhus is dependent on L. scutellare index. These findings could be helpful to monitor the distribution of chigger mites and to develop a preventive measures for scrub typhus in Korea.

Background: Continuous interscalene brachial plexus block (CISB) is well known to reduce postoperative pain and to improve patient satisfaction. However, the effect of CISB on the quality of postoperative recovery is unknown. We Compared the quality of recovery from arthroscopic rotator cuff repair in patients who received CISB or single interscalene brachial plexus block (SISB)., Methods: This prospective non-randomized controlled trial with propensity score matching enrolled 134 patients undergoing arthroscopic surgery for rotator cuff repair. Each patient received an interscalene block before surgery. One group had a catheter insertion 30 min after the end of surgery and started patient-controlled regional analgesia (PCRA, n = 49). The other group received intravenous patient-controlled analgesia (IV-PCA, n = 85). The primary outcome was the quality of recovery (QoR-40) score. Also, postoperative analgesia, sleep quality, and postoperative complications were evaluated., Results: The two groups had similar QoR-40 score on postoperative day-1 (POD1), but the PCRA group had a significantly greater QoR-40 score on POD2 (156.0, IQR: 143.0, 169.0 vs. 171.0, IQR: 159.0, 178.0; p < 0.001). The IV-PCA group received more analgesics during the 2 days after surgery, especially during night-time, and had a higher prevalence of sleep disturbances. The time to first additional analgesics request was significantly longer in PCRA group (14 hours, 95% CI: 13-16 vs. 44 hours, 95% CI: 28-not applicable). The incidence of postoperative nausea and vomiting significantly lower in the PCRA group (16.3% vs 46.9%, p = 0.002)., Conclusion: CISB showed a higher quality of recovery score than SISB with IV-PCA in arthroscopic rotator cuff repair, probably related to the effective analgesia, improved sleep quality, and reduced opioid-related complications.

Study Design: A retrospective study using the Korean Health Insurance Review and Assessment Service-National Sample Cohort was performed., Objective: To determine the rate and causes of mortality in vertebral fracture patients., Summary of Background Data: Vertebral fractures are associated with increased mortality in prior studies., Methods: Of 1,125,691 patients, we collected data of 23,026 patients of all ages who experienced thoracic or lumber vertebral fractures between 2002 and 2013. The vertebral fracture participants were matched 1:4 with control participants, accounting for age, group, sex, income, and region of residence. Finally, 21,759 vertebral fracture participants and 87,036 control participants were analyzed. The index date was the date of diagnosis of vertebral fracture; participants from the control group were followed from the same index date as their matched counterparts. The follow-up duration was the index date to the death date or the last date of study (December 31, 2013). Patients were followed until death or censoring of the data. Death was ascertained in the same period, and causes of death were grouped into 12 classifications according to the Korean Standard Classification of Disease. A stratified Cox proportional hazards model was used., Results: The adjusted hazard ratio (HR) for mortality of vertebral fracture was 1.28 (P < 0.001) with the higher adjusted HR in younger patients. Mortalities caused by neoplasms; neurologic, circulatory, respiratory, digestive, and muscular diseases; and trauma were higher in the vertebral fracture group (P < 0.05), with muscular disease showing the highest odds ratio for mortality., Conclusion: Vertebral fractures were associated with increased mortality in Korean. Disease in muscuoskeletal system and connective tissue that possibly be associated with the fractures was most responsible for elevated death rates following vertebral fracture. Our findings may help caregivers provide more effective care, ultimately decreasing the mortality rate of vertebral fracture patients., Level of Evidence: 3.

Objective: The incidence rate of Parkinson's disease (PD) is growing rapidly owing to the ageing population. We investigated the mortality rates and causes of death in South Korean patients with PD., Design: We investigated a national cohort using the nationwide insurance database., Setting: Korean Health Insurance Review and Assessment Service-National Sample Cohort database., Participants: We included 3510 participants ≥60 years of age who were diagnosed with PD between 2002 and 2013, as well as 14 040 matched controls., Interventions: None PRIMARY AND SECONDARY OUTCOME MEASURES: A stratified Cox proportional hazards model was used to evaluate patients with PD who were matched 1:4 with non-PD control subjects adjusted for age, sex, income and region of residence. The causes of death were grouped into 12 classifications., Results: The adjusted HR for mortality in the PD group was 2.09 (95% CI 1.94 to 2.24, p<0.001). Subgroup analysis according to age (<70 years, 70-79 years, and ≥80 years) and sex revealed that patients with PD showed higher adjusted HRs for mortality across all subgroups. Mortalities caused by metabolic, mental, neurologic, circulatory, respiratory, and genitourinary diseases, as well as trauma, were more common in the PD group than in the control group, with the highest OR observed in patients with neurologic disease., Conclusions: We demonstrated that PD in South Korean patients ≥60 years of age was associated with increased mortality in both sexes regardless of age., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: Chronic inflammatory disease might affect osteoporosis; however, few studies have reported the association between herpes zoster and osteoporosis. The goal of this study was to estimate the association between herpes zoster and osteoporosis in Korean residents., Methods: The Korean National Health Insurance Service-National Sample Cohort, which includes individuals aged ≥ 50 years, was assessed from 2002 to 2013. In total, 68,492 osteoporosis participants were matched with 68,492 control participants at a ratio of 1:1 by age, sex, income, and region of residence. We assayed the prior histories of herpes zoster in the osteoporosis and control groups. The diagnoses of herpes zoster and osteoporosis were based on ICD-10 codes and claim codes. Crude and adjusted models of odds ratios (ORs) were explored using conditional logistic regression analyses, and the 95% confidence intervals (CIs) were computed. The participants were stratified according to age, sex, income, and region of residence. Subgroup analyses were performed to investigate the role of age and sex., Results: The rate of herpes zoster in the osteoporosis group (5.1% [3,487/68,492]) was higher than that in the control group (4.0% [2,738/68,492]). The adjusted OR of herpes zoster in the osteoporosis group was 1.17 (95% CI = 1.11-1.24). In the subgroup analyses, the adjusted OR was 1.34 (95% CI = 1.01-1.78) among males aged < 65 years, 1.20 (95% CI = 1.12-1.29) among females aged < 65 years, and 1.19 (95% CI = 1.04-1.36) among males aged ≥ 65 years., Conclusion: The ORs of herpes zoster were increased among the osteoporosis patients. This correlation was reliable in all subgroups by age and sex except group of women ≥ 65 years old., Competing Interests: The authors declare that there is no conflict of interest regarding the publication of this paper.

Migraine is thought to be associated with Bell palsy. This study aimed to investigate the risk of Bell palsy in migraine patients.The Korean National Health Insurance Service-National Sample Cohort was collected from 2002 to 2013. A total of 45,164 migraine patients were matched for age, sex, income, region of residence, hypertension, diabetes, and dyslipidemia and compared with 180,656 controls. The migraine group included participants diagnosed with migraine [International Classification of Disease (ICD)-10: G43] who underwent treatment more than once. Participants with Bell palsy were included on the basis of the ICD-10 (G510) and treatment with steroids. A history of hypertension, diabetes, and dyslipidemia was determined using ICD-10 codes. Crude (simple) and adjusted hazard ratios (HRs) of Bell palsy in migraine patients were analyzed using the Cox proportional hazards model. Subgroup analyses were conducted based on age and sex.Bell palsy occurred in 0.6% (262/44,902) of the migraine group and 0.5% (903/179,753) of the control group. The adjusted HR of Bell palsy was 1.16 in the migraine group compared with the control group [95% confidence interval (95% CI) = 1.01-1.33, P = .34]. Among age-related subgroups, participants ≥30 and <60 years old in the migraine subgroup demonstrated a 1.28-times higher risk of Bell palsy than the control group (95% CI = 1.05-1.57, P = .014).Migraine increased the risk of Bell palsy in the total population. Among age subgroups, migraine patients ≥30 and <60 years old had an increased risk of Bell palsy.

Objective: This study examined the relationship between sleep duration, sleep quality and food consumption among adolescents., Design: Cross-sectional study., Setting: Data from the 2014 and 2015 Korea Youth Risk Behavior Web-based Survey were used., Participants: Participants aged 12-18 years (n=118 462 (59 431 males and 59 031 females)) were selected., Primary and Secondary Outcome Measures: Sleep duration, sleep quality and the frequencies of fruits, soda, soft drinks, fast food, instant noodle, confectionaries, vegetables and milk consumption., Results: Short sleep durations (<6 hours) were associated with higher soft drinks and confectionaries intake than longer sleep durations (9+ hours) (adjusted ORs (AORs) (95% CIs) for ≥5 times a week for soft drinks: 1.73 (1.57 to 1.91) and confectionaries: 1.32 (1.20 to 1.46); p<0.001). Poor sleep quality, with 7-8 hours of sleep, was associated with a lower intake of fruits, vegetables and milk (AORs (95% CIs) for ≥5 times a week for fruits: 0.71 (0.65 to 0.77); vegetables: 0.66 (0.58 to 0.75); and milk: 0.80 (0.74 to 0.86); each p<0.001), and higher intake of soda, soft drinks, fast food, instant noodle and confectionaries (AORs (95% CIs) for ≥5 times a week for soda: 1.55 (1.40 to 1.70); soft drinks: 1.58 (1.43 to 1.73); fast food: 1.97 (1.65 to 2.35); instant noodle: 1.55 (1.37 to 1.76); and confectionaries: 1.30 (1.18 to 1.43); each p<0.001) than good sleep quality of the same duration., Conclusion: Short sleep durations and poor sleep quality might be associated with higher consumption of unhealthier foods, such as sugar-sweetened beverages, fast food, instant noodle and confectionaries, and associated with lower consumption of fruits, vegetables and milk., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2018. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

The present study investigated the associations of active, passive, and electronic cigarette (E-cigarette) smoking with asthma in Korean adolescents. We used the cross-sectional study of Korea Youth Risk Behavior Web-based Survey conducted in 2011, 2012 and 2013. Active smoking was classified into 4 groups (0 days, 1-5 days, 6-19 days, and ≥20 days a month). Passive smoking was also categorized into 4 groups (0 days, 1-2 days, 3-4 days, and ≥5 days a week). E-cigarette was defined as yes or no in the last 30 days. Age, sex, obesity, region of residence, economic level, and parental educational level were adjusted for as confounders. Smoking variables were adjusted for one another. Adjusted odd ratios (AORs) and 95% confidence intervals (CIs) were calculated using multiple logistic regression analysis with complex sampling. In total, 2.3% (4,890/216,056) of participants reported asthma in the past 12 months. Active smoking was significantly associated with asthma (AOR [95% CI] of smoking ≥20 days/month = 1.57 [1.38-1.77], P < 0.001). Passive smoking was also related with asthma (AOR [95% CI] of smoking ≥5 days/week = 1.40 [1.28-1.53], P < 0.001). E-cigarette showed positive relation with asthma, although the effects of past smoking history could not be excluded (AOR [95% CI] = 1.12 [1.01-1.26], P = 0.027).

Purpose: Since pathophysiologic evidence has been raised to suggest that obesity could facilitate an allergic reaction, obesity has been known as an independent risk factor for allergic disease such as asthma. However, the relationship between sedentary behavior and lifestyle which could lead to obesity, and those allergic diseases remains unclear., Materials and Methods: We analyzed the relations between physical activity, including sitting time for study, sitting time for leisure and sleep time, and obesity, asthma, allergic rhinitis, and atopic dermatitis using the Korea Youth Risk Behavior Web-based Survey, which was conducted in 2013. Total 53769 adolescent participants (12 through 18 years old) were analyzed using simple and multiple logistic regression analyses with complex sampling., Results: Longer sitting time for study and short sitting time for leisure were associated with allergic rhinitis. High physical activity and short sleep time were associated with asthma, allergic rhinitis, and atopic dermatitis. Underweight was negatively associated with atopic dermatitis, whereas overweight was positively correlated with allergic rhinitis and atopic dermatitis., Conclusion: High physical activity, and short sleep time were associated with asthma, allergic rhinitis, and atopic dermatitis., Competing Interests: The authors have no financial conflicts of interest., (© Copyright: Yonsei University College of Medicine 2017)

Objective: Thyrotoxic periodic paralysis (TPP) is characterized by acute onset paralysis and hypokalemia predominantly in male patients with thyrotoxicosis. Recent studies have emphasized the importance of potassium channels, which might explain the underlying mechanism of TPP. The KCNJ2 gene encodes the inward-rectifying potassium channel. In this study, we evaluated the role of KCNJ2 in the development of TPP. Design: Case-control analysis of KCNJ2 genetic association with TPP. Patients: 83 male patients with Graves' disease (GD) were recruited for this study; 43 patients had TPP, whereas 40 patients had no history of TPP. Measurements: We analyzed the genotype and allelic frequency of a single-nucleotide polymorphism (SNP; rs312691) (C>T) adjacent to the KCNJ2 gene that is known to be related to TPP development. Results: The frequency of the CC genotype of the rs312691 SNP was 0.51 in TPP patients and 0.05 in controls ( p- value=6.18×10 -6 ). The C allele frequency of the SNP was 0.67 in the TPP group and 0.38 in the control group (odds ratio 3.24; 95% confidence interval 1.65-6.51; p- value, 3.1×10 -4 ). The rs312691 SNP was significantly associated with TPP. Conclusions: We demonstrated that the rs312691 SNP was significantly associated with TPP. These findings suggest that KCNJ2 plays an important role in the pathophysiology of TPP in Korean GD patients with TPP., (© Georg Thieme Verlag KG Stuttgart · New York.)

The objective of this study was to evaluate the association between falls and obesity using Asian body mass index (BMI) classifications. Using the data from the Korean community health survey in 2011, a total of 229,226 participants ranging from 19 to 106 years old were included in this study. The BMI groups were classified as underweight (<18.5), healthy (18.5 ≤ BMI < 23), overweight (23 ≤ BMI <25), and obese (≥25) using Asian BMI classifications. The associations between BMI groups and falls (≥1 time or ≥2 times per year) were analyzed using multiple logistic regression analyses with complex sampling. A subgroup analysis was conducted according to age (19-40, 41-60, and ≥61 years) and the location of the fall (indoor and outdoor). Physical activity, household income, education level, alcohol consumption, smoking, stress level, and medical comorbidities were adjusted as confounders. In total, 16.8% and 6.1% of the participants experienced falls ≥1 time and ≥2 times per year, respectively. Compared to the healthy weight group, the other BMI groups showed a significant U-shaped relationship with falls ≥1 time (AOR underweight = 1.12, 95% CI [confidence interval] = 1.05-1.19; AOR obese = 1.06, 95% CI = 1.02-1.10, P < 0.001) and ≥2 times (AOR underweight = 1.14, 95% CI = 1.04-1.26; AOR obese = 1.04, 95% CI = 0.99-1.10, P < 0.001). Obese status was significantly associated with falls (≥1 fall per year) in all age groups, whereas being underweight was significantly associated with falls in the 19 to 40 year age group only. In conclusion, both underweight and obese statuses were significantly associated with falls in this adult Korean population. However, the relationship between BMI group and falls varied according to age and the location of the falls., Competing Interests: The authors have no conflicts of interest to disclose.

Background: Numerous studies have suggested that nutritional intake is related to allergic diseases. Although conflicting results exist, fat intake is often associated with allergic diseases. We investigated the relationship between allergic diseases and nutritional intake after adjusting for various demographic and socioeconomic factors in a large, representative sample of Korean children., Methods: A total of 3,040 participants, aged 4 to 13 years old, were enrolled in the present study from the Korean National Health and Nutrition Examination Survey (KNHANES), 2010-2012. Nutritional intake data, including total calories, protein, fat, carbohydrate, vitamin A, vitamin C, thiamine, riboflavin, and niacin, were retrieved from the survey using the complete 24-hour recall method. The associations between each nutritional factor and allergic rhinitis/asthma/atopic dermatitis were analyzed using simple and multiple logistic regression analyses with complex sampling. Age, sex, body mass index (BMI), number of household members, income level, and region of residence were adjusted for as covariates., Results: Of the participants, 22.1%, 6.0%, and 15.5% suffered from allergic rhinitis, asthma, and atopic dermatitis, respectively. Allergic rhinitis was significantly correlated with high-fat and low-carbohydrate diets. The adjusted odds ratio (AOR) was 1.25 (95% CIs = 1.06-1.46, P = 0.007) for fat intake, denoting a 10% increase. Carbohydrate intake (10% increase) was negatively related to allergic rhinitis with an AOR of 0.84 (95% CIs = 0.74-0.95, P = 0.004). No other significant relationships were found between the retrieved nutritional factors and either asthma or atopic dermatitis., Conclusion: Allergic rhinitis was related to high-fat and low-carbohydrate diets. Although the underlying mechanisms and causal relationships remain elusive, the present study provides reliable evidence regarding the associations between nutritional factors and allergic rhinitis by considering numerous factors within a large and representative population.

A correction method using machine learning aims to improve the conventional linear regression (LR) based method for correction of atmospheric pressure data obtained by smartphones. The method proposed in this study conducts clustering and regression analysis with time domain classification. Data obtained in Gyeonggi-do, one of the most populous provinces in South Korea surrounding Seoul with the size of 10,000 km(2), from July 2014 through December 2014, using smartphones were classified with respect to time of day (daytime or nighttime) as well as day of the week (weekday or weekend) and the user's mobility, prior to the expectation-maximization (EM) clustering. Subsequently, the results were analyzed for comparison by applying machine learning methods such as multilayer perceptron (MLP) and support vector regression (SVR). The results showed a mean absolute error (MAE) 26% lower on average when regression analysis was performed through EM clustering compared to that obtained without EM clustering. For machine learning methods, the MAE for SVR was around 31% lower for LR and about 19% lower for MLP. It is concluded that pressure data from smartphones are as good as the ones from national automatic weather station (AWS) network.

Few studies have evaluated the impacts of excessive sleep duration on falls. This study investigated the associations between sleep duration and falls among Korean adults in a wide range of age groups while adjusting for numerous confounding factors. Data collected from study participants ranging in age from 19 to 109 years old were analyzed from the 2013 Korean Community Health Survey (KCHS). Sleep duration was divided into 5 groups: ≤5, 6, 7, 8, and ≥9  hours per day. The relations between sleep duration and falls (≥1 time or ≥2 times per year) were analyzed using simple and multiple logistic regression analyses with complex sampling. Age, sex, days of vigorous or moderate physical activity, income, education, alcohol use, smoking, stress, obesity, hypertension, diabetes mellitus, hyperlipidemia, stroke, angina or myocardial infarction, arthritis, and asthma were controlled for as confounding factors. Associations between sleep duration and falls were analyzed in 19 to 40, 41 to 60, and 61+ year age groups. Furthermore, the relations between sleep duration and indoor versus outdoor falls were analyzed. Both ≤6 and ≥8  hours of sleep per day were significantly associated with an increased incidence of falls (≥1 time and ≥2 times per year) in the overall adult population (P < 0.001 in both instances). In a subgroup analysis, sleep durations of ≤5 and ≥9  hours were significantly associated with an increased incidence of falls (≥1 time a year) in each age group. Six hours of sleep was not significantly associated with falls (≥2 times per year) in the 61+ year age group, and 8 and 9  hours of sleep were not significantly associated with falls (≥2 times a year) in the 19 to 40 year age group. This study demonstrated that long as well as short sleep durations are associated with an increased incidence of falls. However, these relations were not evident in elderly populations with short sleep durations or in young adults with long sleep durations., Competing Interests: The authors have no conflicts of interest to disclose.

Research on the effect of low-fat intake on hearing is limited. This study aimed to elucidate the relationship between fat, carbohydrate and protein intake and the presence of hearing discomfort among the elderly. The Korean National Health and Nutrition Examination Survey was conducted from 2009 through to 2012. A total of 4615 participants ranging in age from 60 to 80 years underwent a pure-tone audiometric evaluation, a physical examination and a nutritional survey. The associations between the participants' hearing thresholds and their protein/fat/carbohydrate intake/total energy intake were analysed using simple and multiple regression models with complex sampling adjusted for confounding factors, such as BMI, income level, smoking status and a history of hypertension, hyperlipidaemia and diabetes. Low fat and protein intakes were associated with hearing discomfort (OR 0·82, 95 % CI 0·71, 0·96, P=0·011; OR 0·81, 95 % CI 0·67, 0·96, P=0·017, respectively). This study revealed that low fat and protein intakes are associated with hearing discomfort in the elderly Korean population.

Low physical activity, long leisure sitting time, and short sleep time are risk factors for obesity, but the association with study sitting time is unknown. The objective of this study was to evaluate the association between these factors and obesity.We analyzed the association between physical activity, study sitting time, leisure sitting time, and sleep time and subject weight (underweight, healthy weight, overweight, and obese), using data from a large population-based survey, the 2013 Korea Youth Risk Behavior Web-based Survey. Data from 53,769 participants were analyzed using multinomial logistic regression analyses with complex sampling. Age, sex, region of residence, economic level, smoking, stress level, physical activity, sitting time for study, sitting time for leisure, and sleep time were adjusted as the confounders.Low physical activity (adjusted odds ratios [AORs] = 1.03, 1.12) and long leisure sitting time (AORs = 1.15, 1.32) were positively associated with overweight and obese. Low physical activity (AOR = 1.33) and long leisure sitting time (AOR = 1.12) were also associated with underweight. Study sitting time was negatively associated with underweight (AOR = 0.86) but was unrelated to overweight (AOR = 0.97, 95% confidence interval [CI] = 0.91-1.03) and obese (AOR = 0.94, 95% CI = 0.84-1.04). Sleep time (<6 hours; ≥6 hours, <7 hours; ≥7 hours, <8 hours) was adversely associated with underweight (AORs = 0.67, 0.79, and 0.88) but positively associated with overweight (AORs = 1.19, 1.17, and 1.08) and obese (AORs = 1.33, 1.36, and 1.30) in a dose-response relationship.In adolescents, increasing physical activity, decreasing leisure sitting time, and obtaining sufficient sleep would be beneficial in maintaining a healthy weight. However, study sitting time was not associated with overweight or obese.

This study was conducted to estimate the prevalence and associated factors of subjective halitosis in adolescents. In total, 359,263 participants were selected from the Korea Youth Risk Behavior Web-based Survey (KYRBWS) from 2009 through 2013. Demographic data including age, sex, obesity and residency; psychosocial factors such as subjective health, stress, and economic levels; and dietary factors such as alcohol consumption; smoking; and fruit, soda, fast food, instant noodle, confection, and vegetable consumption were analyzed for correlations with halitosis using simple and multiple logistic regression analyses with complex sampling. In total, 23.6% of the participants reported the presence of halitosis. The following subjectively assessed factors were related to halitosis: poor health status (adjusted odds ratio [AOR] = 2.56), overweight or obese (AOR = 1.37), stress (AOR = 2.56), and lower economic levels (AOR = 1.85). The high intake of fast food (AOR = 1.15), instant noodles (AOR = 1.17), and confections (AOR = 1.17) and the low intake of fruits (AOR = 1.22) and vegetables (AOR = 1.19) were also related to halitosis. The prevalence of subjective halitosis in the studied adolescents was 23.6%. Specific psychosocial factors and dietary intake were related to halitosis.

Objective: To examine the relationship of early life socioeconomic position (SEP) and adulthood periodontitis in the middle aged Korean representative sample., Methods: The 4th Korea National Health and Nutrition Examination Survey data were used. Multivariate logistic regression analyses were conducted on adults aged 30-59 years to estimate the association between parental SEP (education, occupation) and periodontitis and assess the relative impacts of own SEP (education, income and occupation) on periodontitis. Periodontitis (Community Periodontal Index) was dependent variable and parental SEPs were independent variables., Results: Own SEP was associated with periodontitis (OR of own education=1.94, OR of own occupation=1.67; OR of the lowest income=1.52). Income was associated with periodontitis after adjustment for own SEPs and parental SEPs simultaneously (adjusted OR of the lowest income=1.68). Parental SEP was associated with periodontitis (OR of father's education=1.66, OR of mother's education=l.64; OR of father's occupation=1.38, OR of mother's occupation=1.44)., Conclusions: Early-life socioeconomic disadvantages were significantly associated with adulthood periodontitis in the representative Korean sample (p<0.05). The results also indicated that systematic oral health program and oral education would be needed from early childhood throughout the whole life time to improve periodontal health in adulthood.

Objective: This study sought to evaluate associations between sleep time and bicycle accidents, falls under various circumstances, and dental injuries in adolescents., Methods: A total of 61,696 participants ranging from 12 to 18 years of age who completed the Korea Youth Risk Behavior Web-based Survey (KYRBWS) in 2013 were enrolled in this study. Bicycle riding accidents were analyzed for 17,232 bicycle-riding participants. Data were collected regarding the weekday sleep duration for the most recent 7 days, which was categorized as < 5.5 h, 5.5-6.5 h, 6.5-7.5 h, or ≥ 7.5 h per day, and the incidence of bicycle accidents, slips and falls under various circumstances, and dental injuries in the most recent 12 months. Adjusted odds ratios (aORs) were calculated among sleep groups for bicycle accidents, slips and falls, and dental injuries using simple and multiple logistic regression analyses with complex sampling., Results: Bicycle riding accidents and slips and falls in classrooms, corridors, the ground, toilets, stairs, and other unspecified situations showed positive correlations with sleep deprivation. Comparisons of groups with ≥ 7.5 h sleep, < 5.5 h, 5.5-6.5 h sleep, and 6.5-7.5 h sleep revealed increased associations with slips and falls under various circumstances. In particular, the aORs were higher in the groups with less sleep (aOR of the 5.5 h group > the 5.5-6.5 h group > the 6.5-7.5 h group). There was no significant relationship between sleep deprivation and dental injury., Conclusions: This study demonstrated that sleep deprivation among Korean adolescents was associated with bicycle accidents and falls at home and school. Thus, adequate sleep may be needed to prevent accidents and falls.

We aimed to estimate the effects of various risk factors on hearing level in Korean adults, using data from the Korea National Health and Nutrition Examination Survey. We examined data from 13,369 participants collected between 2009 and 2011. Average hearing thresholds at low (0.5, 1, and 2 kHz) and high frequencies (3, 4, and 6 kHz), were investigated in accordance with various known risk factors via multiple regression analysis featuring complex sampling. We additionally evaluated data from 4,810 participants who completed a questionnaire concerned with different types of noise exposure. Low body mass index, absence of hyperlipidemia, history of diabetes mellitus, low incomes, low educational status, and smoking were associated with elevated low frequency hearing thresholds. In addition, male sex, low body mass index, absence of hyperlipidemia, low income, low educational status, smoking, and heavy alcohol consumption were associated with elevated high frequency hearing thresholds. Participants with a history of earphone use in noisy circumstances demonstrated hearing thresholds which were 1.024 dB (95% CI: 0.176 to 1.871; P = 0.018) higher, at low-frequencies, compared to participants without a history of earphone use. Our study suggests that low BMI, absence of hyperlipidemia, low household income, and low educational status are related with hearing loss in Korean adults. Male sex, smoking, and heavy alcohol use are related with high frequency hearing loss. A history of earphone use in noisy circumstances is also related with hearing loss.

Background: Tinnitus is a common condition in adults; however, the pathophysiology of tinnitus remains unclear, and no large population-based study has assessed the associated risk factors. The aim of this study was to analyze the prevalence and associated risk factors of tinnitus., Methods: We conducted a cross-sectional study using data from the Korea National Health and Nutrition Examination Survey, with 19,290 participants ranging in age from 20 to 98 years old, between 2009 and 2012. We investigated the prevalence of tinnitus using a questionnaire and analyzed various possible factors associated with tinnitus using simple and multiple logistic regression analysis with complex sampling., Results: The prevalence of tinnitus was 20.7%, and the rates of tinnitus associated with no discomfort, moderate annoyance, and severe annoyance were 69.2%, 27.9%, and 3.0%, respectively. The prevalence of tinnitus and the rates of annoying tinnitus increased with age. The adjusted odds ratio (AOR) of tinnitus was higher for females, those with a smoking history, those reporting less sleep (≤ 6 h), those with more stress, those in smaller households, those with a history of hyperlipidemia osteoarthritis, rheumatoid arthritis, asthma, depression, thyroid disease, an abnormal tympanic membrane, unilateral hearing loss, bilateral hearing loss, noise exposure from earphones, noise exposure at the workplace, noise exposure outside the workplace, and brief noise exposure. Additionally, unemployed individuals and soldiers had higher AORs for tinnitus. The AOR of annoying tinnitus increased with age, stress, history of hyperlipidemia, unilateral hearing loss, and bilateral hearing loss., Conclusions: Tinnitus is very common in the general population and is associated with gender, smoking, stress, sleep, hearing loss, hyperlipidemia, osteoarthritis, rheumatoid arthritis, asthma, depression, and thyroid disease history.

Hymenoptera stings can cause serious injury to humans. We report the clinical findings of 6 cases of Hymenoptera stings. All patients developed painful erythematous papules at the sting sites and had a past history of parasitoid wasp sting. This is the first clinical report of the parasitoid wasp, Cephalonomia gallicola, causing human stings in Korea.

Monthly surveys were conducted to investigate the occurrence of chigger mites and seroprevalence of scrub typhus among small mammals in Jeollanam-do, the southwestern part of Korea, from November 2006 through October 2007. Fifty-eight small mammals, including 57 Apodemus agrarius (98.3%) and 1 Crocidura lasiura (1.7%), were captured, and a total of 4,675 chigger mites representing 4 genera and 8 species were collected from them. The chigger infestation rate among small mammals was 69.0%. The most predominant species in A. agrarius was Leptotrombidium scutellare (54.0%), followed by Leptotrombidium pallidum (39.4%), Leptotrombidium orientale (4.4%), Leptotrombidium palpale (1.1%), Neotrombicula tamiyai (0.6%), Eushoengastia koreaensis (0.3%), Neotrombicula gardellai (0.3%), and Cheladonta ikaoensis (<0.1%). The chigger index of A. agrarius was the highest in October (740.0), followed by November (242.0), September (134.6), March (98.3), February (38.2), January (35.3), December (34.5), April (30.8), and May (1.7). The average antibody positive rate of scrub typhus in wild rodents was 50.0%. The seropositive rates were high in October (100.0%) and November (83.3%), whereas those in other months were relatively low (28.6-57.1%). The chigger index of L. scutellare rapidly increased in September to form an acuminate peak in October, followed by a gradual decline. These results suggest that the outbreak of scrub typhus in the southwestern part of Korean peninsula is mostly due to L. scutellare.

Head louse infestation (HLI) is one of the most frequently occurring parasitic diseases in children. This study was conducted to investigate the socioeconomic and personal factors influencing HLI in the Republic of Korea. A total of 2,210 questionnaires about various factors related to HLI were obtained from children in 17 primary schools throughout the country. The rate of HLI was significantly lower in children who lived together with mother or in a family where both parents worked. In addition, HLI was lower in children whose fathers or mothers were public officers or teachers. However, HLI was higher in children who had small families and washed their hair less often. Education levels of parents and the number of children in family were not significant. Improvement of socioeconomic factors and personal hygiene will be helpful for reducing HLI.