Association between dental diseases and oral hygiene care and the risk of vertebral fracture: a nationwide cohort study.

Periodontal disease and increased missing teeth were associated with incident vertebral fractures. In contrast, professional dental cleaning and frequent tooth brushing, was associated with a lower risk of vertebral fracture. Better oral hygiene care attenuated the risk associated with dental diseases. PURPOSE: To investigate the association between oral health and the risk of vertebral fractures. METHODS: We included 2,532,253 individuals aged ≥40 years who underwent the Korean National Health Insurance Service health examinations in 2008 and followed up until December 31, 2017. We performed multivariable Cox proportional hazard regression analyses to evaluate the association between dental diseases and oral hygiene care and the risk of vertebral fractures. RESULTS: Over the 9.3-year median follow-up, 1.46% (n = 36,857) experienced vertebral fractures. Individuals with dental diseases had a higher risk of vertebral fracture than those without (hazard ratio [HR] 1.04, 95% confidence interval [CI]: 1.02-1.07 for periodontal diseases; 1.02, 1.00-1.05 for dental caries; 1.12, 1.05-1.20 for ≥15 missing teeth). Good oral hygiene care was associated with a lower vertebral fracture risk (HR 0.89, 95% CI: 0.86-0.91 for ≥1 time/year [vs. <1 time/year] of professional dental cleaning; 0.90, 0.87-0.93 for ≥2 times/day [vs. 0-1 time/day] of toothbrushing). The combined dental diseases was significantly associated with an increased vertebral fracture risk, whereas combined oral hygiene care was associated with further risk reduction. Better oral hygiene care reduced vertebral fracture risk associated with dental diseases (all P <0.001). CONCLUSION: Periodontal disease, dental caries, and an increased number of missing teeth were independently associated with higher risks for vertebral fractures. Conversely, improved oral hygiene care, such as personal dental cleaning and frequent tooth brushing, may modify vertebral fracture risks associated with dental disease.

Bone Mineral Density and the Risk of Parkinson's Disease in Postmenopausal Women.

BACKGROUND: Whether bone mineral density (BMD) is related to the risk of Parkinson's disease (PD) is unclear. OBJECTIVES: The objective of this study was to examine the association between BMD status and incident PD in postmenopausal women. METHODS: We retrospectively examined a nationwide cohort of 272,604 women aged 66 years who participated in the 2009-2012 Korean national health screening for transitional ages. BMD was evaluated using dual-energy X-ray absorptiometry of the central bones. The use of antiosteoporosis medications (AOMs) was assessed. We performed multivariable Cox proportional hazards regression to evaluate the association between BMD and PD risk by calculating hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: During the median follow-up of 7.7 years, 2,884 (1.1%) incident PD cases developed. After adjusting for confounding factors, lower BMD was associated with an increased risk of PD (P for trend <0.001). Individuals with osteoporosis had a 1.40-fold higher HR (1.40, 95% CI: 1.25-1.56) than those with a normal BMD. Sensitivity analyses suggested the associations robust to longer lag periods and further adjustment. These associations were prominent in individuals without AOM use before or after enrollment (P for interaction = 0.031 and 0.014). Increased risks of PD in individuals with osteopenia and osteoporosis who did not use AOMs were attenuated by the medication use during the follow-up period, regardless of previous AOM use. CONCLUSIONS: Lower postmenopausal BMD and osteoporosis were associated with an increased risk of PD. In addition, this association could be mitigated using AOMs. Proper management of BMD in postmenopausal women may help prevent PD. © 2023 International Parkinson and Movement Disorder Society.

Weight Gain, Comorbidities, and Its Associated Factors Among Korean Adults.

BACKGROUND: Weight gain in adults is associated with an increased risk of obesity-related diseases and high healthcare costs. However, there have been limited studies on weight gain in Asians. This study investigated the prevalence, comorbidities, and associated factors of weight gain in the Korean population. METHODS: This is a cross-sectional study of Korean adults aged 19-64 years who participated in the Korea National Health and Nutritional Examination Survey 2016-2019. We used data from 15,514 adults (subjects 1) to analyze the prevalence of weight gain. Finally, after excluding adults with suspicious debilitating conditions among them, 11,477 adults (subjects 2) were used to analyze comorbidities and associated factors. Weight changes and lifestyle factors were assessed using a self-report questionnaire. We analyzed odds ratios and 95% confidence intervals using multivariable logistic regression analysis to examine factors associated with weight gain. RESULTS: The overall prevalence of weight gain was 25.7% in men and 31.3% in women and decreased significantly with age in both sexes. Weight gain of ≥ 6 kg was evident in 10.5% of men and 9.8% of women and was more pronounced with a higher baseline body mass index (BMI). Most metabolic comorbidities worsened the greater the weight gain. Young age was the strongest associated factor for weight gain. Other factors associated with weight gain were being unmarried, blue-collar job, lower income, and alcohol consumption in men; being married in women; smoking and skipping breakfast in both sexes. CONCLUSION: Weight gain was much more pronounced in younger adults and at a higher baseline BMI in both sexes. Public education and health policies to prevent unnecessary weight gain should be strengthened by considering the associated harmful factors in Korean adults.

Age at menopause and risk of heart failure and atrial fibrillation: a nationwide cohort study.

AIMS: This study aimed to examine the association of premature menopause and age at menopause with the risk of heart failure (HF) and atrial fibrillation (AF). METHODS AND RESULTS: A total of 1 401 175 postmenopausal women, who had undergone health examination provided by the Korean National Health Insurance Service, were included, and their reproductive histories were collected. Multivariable Cox proportional hazard models were performed to determine the hazard ratios (HRs) and 95% confidence intervals (CIs) of incident HF and AF, according to the history of premature menopause and age at menopause. At a mean follow-up of 9.1 years, there were 42 699 (3.0%) and 44 834 (3.2%) new cases of HF and AF, respectively. Women with history of premature menopause had an increased risk of HF (HR: 1.33, 95% CI: 1.26-1.40) and AF (HR: 1.09, 95% CI: 1.02-1.16), compared to women without the history. Compared with women aged ≥50 years at menopause, those aged 45-49, 40-44, and <40 years at menopause showed a significantly increased trend in HRs for the incident risk of both HF and AF (P for trend <0.001). The robustness of the results of a series of sensitivity analyses further strengthens the main findings. CONCLUSION: Our findings suggest that postmenopausal women with a history of premature menopause or early menopausal age may have an increased risk of HF and AF. These reproductive factors need to be considered for preventing the future risk of HF and AF.

Association of Smoking Status With the Risk of Type 2 Diabetes Among Young Adults: A Nationwide Cohort Study in South Korea.

INTRODUCTION: The longitudinal evidence between detailed parameters of smoking status and type 2 diabetes among young adults has been limited. We evaluated this association in young Korean adults. METHODS: This nationwide cohort study included 3 026 551 adults aged 20 to 39 years who underwent Korean National Health Insurance Service health examinations in 2009 and were followed up until the end of 2017. The participants were categorized according to smoking status, smoking duration, and smoking amount. The hazard ratios (HRs) and 95% CIs for type 2 diabetes were estimated using multivariable Cox proportional hazard regression analysis. RESULTS: During 8.2 years of follow-up, 71 952 cases of type 2 diabetes newly developed. Compared with never-smokers, independently increased HRs of type 2 diabetes were observed in ex-smokers (1.06, 95% CI = 1.04-1.09) and current smokers (1.39, 1.36-1.42). In these two groups, the type 2 diabetes risk increased with greater smoking duration and amount (p for trend <.001). The HRs of type 2 diabetes were higher in current smokers than in ex-smokers at the same lifetime smoking amount. The associations between smoking status and incident type 2 diabetes were stronger in men, individuals who did not drink heavily, and those without obesity. CONCLUSIONS: Among young adults, past and current smoking was associated with an increased risk of type 2 diabetes, and there was a dose-response association of smoking amount and duration with type 2 diabetes development. Appropriate interventions to help young adults cease smoking may help reduce the incidence of type 2 diabetes. IMPLICATIONS: Smoking was associated with an increased risk of type 2 diabetes among young adults, and the risk was shown to increase as amount and duration of smoking increased. Ceasing smoking in young adults may help reduce the incidence of type 2 diabetes.

Trends in the high blood glucose and non-alcoholic fatty liver disease among Korean adolescents.

High blood glucose level and non-alcoholic fatty liver disease (NAFLD) in adolescents are long-term risk factors for cardiovascular diseases and poor prognosis. We investigated recent trends of high blood glucose levels and NAFLD among Korean adolescents aged 12-18 years. We conducted a cross-sectional analysis using data of 5,685 adolescents aged 12-18 years from the Korea National Health and Nutrition Examination Surveys (KNHANES), from 2007-2009 to 2016-2018. Linear trends in the prevalence of high blood glucose level, NAFLD, and associated factors were assessed using multivariable logistic regression analyses. During the study period, the odds ratios for high blood glucose level and NAFLD increased significantly in both sexes and in girls, respectively (p for trend <0.05). Over-consumption of total calories in boys and fat intake in boys and girls increased significantly (p for trend <0.05). In Korean adolescents, the prevalence of high blood glucose level and NAFLD has increased recently. Efforts to modify the associated factors and further research to determine the public health measures are warranted to prevent these metabolic abnormalities in adolescents.

Association between type of exercise and health-related quality of life in adults without activity limitations: a nationwide cross-sectional study.

BACKGROUND: Exercise is known to be associated with health-related quality of life (HRQoL), however, evidence on the association between type of exercise and HRQoL in the general population is limited. We performed this study to investigate the association of exercise types and their combinations with HRQoL in Korean adults. METHODS: We analyzed data from 13,437 adults aged ≥19 years without activity limitations who had participated in the 5th Korea National Health and Nutrition Examination Survey 2010-2012. As per the American College of Sports Medicine guideline, exercise types were categorized into eight groups: walking (W), flexibility (F), resistance (R), W + F, W + R, F + R, and W + F + R exercise groups and a non-exercise group. The European Quality of Life-5 Dimension (EQ-5D) index and the European Quality of Life Visual Analogue Scale (EQ-VAS) were used to assess HRQoL. RESULTS: The mean age of participants was 42.8 ± 0.2 years. The proportion of participants in the non-exercise group was the highest (34.7%); among the exercise groups, the walking group was the most prevalent (16.9%) and the W + R group was the least (1.2%). In analysis of covariance, the mean EQ-5D index in W (0.875), W + F (0.878), F + R (0.877), and W + F + R (0.876) groups was significantly higher compared with that in non-exerciser group (0.869) (p < 0.05). The mean EQ-VAS score in the W (64.064), F (64.427), W + F (65.676), F + R (65.811), and W + F + R (67.110) groups was higher than that in the non-exercise group (62.396) (p < 0.05). No difference was observed between R and W + R groups and non-exercise group with regard to the EQ-5D index and EQ-VAS score. CONCLUSIONS: The W (for 30 min at least five times a week), W + F, F + R (at least two days a week), and W + F + R groups showed higher HRQoL than the non-exercise group. This study may be helpful in the development of public exercise interventions, which could help enhance HRQoL in adults.

Obesity, abdominal obesity and subsequent risk of kidney cancer: a cohort study of 23.3 million East Asians.

BACKGROUND: Limited evidence exists regarding associations between obesity and kidney cancer among Asians. We examined the associations between obesity measures and risk of kidney cancer. METHODS: We included 23,313,046 adults who underwent health examinations provided by the Korean National Health Insurance Service 2009-2012 and performed multivariable Cox proportional hazards regression analyses. RESULTS: During 5.4 years of follow-up, 18,036 cases of kidney cancer were recorded, and cumulative incidence was 0.12%. General and abdominal obesity were associated with 1.32-fold increased risk of kidney cancer compared with groups without either obesity status. Underweight individuals showed decreased adjusted hazard ratio (HR) for kidney cancer (0.76, 95% confidence interval: 0.68-0.85) compared to those with normal body mass index (BMI), while the HRs increased among individuals with BMI 23-24.9 kg/m2 (1.23, 1.18-1.28), 25-29.9 kg/m2 (1.41, 1.36-1.46) and ≥30 kg/m2 (1.77, 1.65-1.90) (P for trend < 0.001). HRs of kidney cancer increased with increasing waist circumference (WC) (P for trend < 0.001). Compared to non-obese condition, the coexistence of general and abdominal obesity increased the HR (1.45, 1.40-1.50). CONCLUSIONS: This study demonstrated positive associations of BMI and WC with kidney cancer risk. General and abdominal obesity may be risk factors of kidney cancer.

Abrogation of B-RafV600E induced senescence by FoxM1 expression.

B-RafV600E oncogene mutation occurs in various cancers and is associated with tumor initiation. However, genetic modification of B-RafV600E in cells induces MAPK activation and results in oncogene-induced senescence. Overcoming the oncogene-induced senescence by B-RafV600E requires activation of another oncogene pathway, such as AKT signaling. In the present study, we explored the factors involved in overcoming the senescence program in cells activated by B-RafV600E and AKT signaling. B-RafV600E activation caused a feedback inhibition of AKT phosphorylation and resulted in downregulation of FoxM1, one of the AKT downstream components. AKT activation by PTEN downregulation induced FoxM1 expression, and co-expression of B-RafV600E and FoxM1 overcame the cellular senescence. These observations suggested that FoxM1 is critical downstream gene of AKT and functions to overcome B-RafV600E-induced senescence.

Impact of body mass index and body weight variabilities on mortality: a nationwide cohort study.

BACKGROUND/OBJECTIVES: There is limited information regarding the impact of body mass index (BMI) and body weight (BWt) variabilities on mortality. This study aimed to investigate the association between BMI, BWt variabilities and subsequent mortality in the Korean population. SUBJECTS/METHODS: This study used a representative sample cohort enrolled in the national health examination program conducted by the Korean National Health Insurance Service, and 125,391 individuals were included and followed up until 2013 (mean follow-up period = 84 months). BMI and BWt variabilities were estimated as the standard deviation (SD) and coefficient of variation (CV) of serial measurements of BMI and BWt (BMI_SD, BWt_SD, BMI_CV, and BWt_CV). Cox proportional hazard regression models were used to evaluate the all-cause and cause-specific mortality according to variability indices. RESULTS: Baseline BMI showed a non-linear association with all-cause mortality. The highest quartile (Q4) groups of variability indices were associated with increased all-cause mortality risk compared to the lowest quartile (Q1) groups after adjusting for confounding factors (hazard ratio [95% confidence interval] = 1.23 [1.11-1.37] for BMI_SD; 1.25 [1.06-1.47] for BMI_CV; 1.33 [1.20-1.48] for BWt_SD; 1.42 [1.28-1.58] for BWt_CV). The hazard ratios of all-cause mortality increased from the Q2 to the Q4 groups of variability indices, in each sex group and among individuals aged ≥40 years. Furthermore, Q4 groups of variability indices were positively associated with cause-specific mortality compared to groups with Q1-Q3 of the indices (1.28 [1.05-1.56] for BWt_SD, 1.21 [1.001-1.47] for BMI_CV, 1.29 [1.06-1.56] for BWt_CV regarding cardiovascular diseases mortality; 1.18 [1.03-1.36] for BWt_SD, 1.21 [1.06-1.39] for BMI_CV, 1.26 [1.10-1.44] for BWt_CV regarding cancer mortality). CONCLUSIONS: Our results suggest that BMI and BWt variabilities are independent risk factors for all-cause and cause-specific mortality.

Weight change and mortality and cardiovascular outcomes in patients with new-onset diabetes mellitus: a nationwide cohort study.

BACKGROUND: Because weight control is a cornerstone of diabetes management, it is important to understand the relationship of weight change to risk of cardiovascular disease (CVD) among patients with type 2 diabetes mellitus (DM). We aimed to investigate whether changes in weight early after diagnosis influence the incidence of CVD and all-cause mortality in patients with type 2 DM. METHODS: Using nationally representative data from the Korean National Health Insurance System, 173,246 subjects with new-onset DM who underwent health examinations during 2007-2012 were included. Weight was measured at the time of diabetes diagnosis and 2 years later. Weight change over 2 years was divided into five categories of 5% weight change, from weight loss ≥ - 10% to weight gain ≥ 10%. RESULTS: There were 3113 deaths (1.8%), 2060 cases of stroke (1.2%), and 1767 myocardial infarctions (MIs) (1.0%) during a median follow-up of 5.5 years. Subjects with weight gain ≥ 10% had a significantly higher risk of stroke (hazard ratio [HR] 1.51, 95% confidence interval [CI] 1.23-1.84), compared with the group with stable weight. There was no significant association between weight change after diagnosis of DM and incident MI. All-cause mortality showed a U-shaped curve according to weight change. The group with weight loss ≥ - 10% had the highest HR for all-cause mortality (HR 1.86; 95% CI 1.61-2.14) and the HR for weight gain ≥ 10% was 1.61 (95% CI 1.37-1.89). CONCLUSIONS: Weight changes of more than 10% after diabetes diagnosis were associated with higher mortality and over 10% weight gain was associated with increased risk of stroke.

Chronic renal dysfunction, proteinuria, and risk of Parkinson's disease in the elderly.

BACKGROUND: The roles of chronic kidney disease and proteinuria in the development of Parkinson's disease have not been widely studied. The objective of this study was to examine the associations of chronic renal dysfunction and proteinuria with the risk of PD in older adults using cohort data of the whole South Korean population. METHODS: We included 3,580,435 individuals aged ≥65 years who had undergone health checkups provided by the National Health Insurance Service of South Korea between 2009 and 2012 and were followed until 2015. Multivariable Cox proportional hazards regression models were performed. RESULTS: During a mean follow-up of 5.2 ± 1.3 years, 30,813 individuals (0.86% of the total population) developed PD. Lower estimated glomerular filtration rate and a higher degree of proteinuria on a dipstick test were associated with higher incidence probability of PD (log-rank P < 0.001). In Cox regression models, chronic renal dysfunction graded by estimated glomerular filtration rate (mL/min/1.73 m2 ) was associated with increased risk of PD after adjusting for potential confounding variables; hazard ratio (95% confidence interval) was 1.13 (1.10-1.17) for estimated glomerular filtration rate 60-90, 1.36 (1.31-1.42) for estimated glomerular filtration rate 30-60, and 1.47 (1.32-1.63) for estimated glomerular filtration rate <30 (P for trend <0.001). Proteinuria ≥1+ was also associated with increased risk of PD development (hazard ratio, 1.12; 95% confidence interval, 1.06-1.18). Coexistence of chronic kidney disease and proteinuria showed an increased hazard ratio of 1.33 (95% confidence interval, 1.23-1.45) for PD occurrence. CONCLUSIONS: Our findings suggest that chronic renal dysfunction and dipstick-positive proteinuria may be independent risk factors for the development of PD in older adults. © 2019 International Parkinson and Movement Disorder Society.

Association between height and hypercholesterolemia in adults: a nationwide population-based study in Korea.

BACKGROUND: Previous studies reported that stature is inversely related to the risk of cardiovascular disease. However, there is limited evidence on the association between height and lipid profiles. We aimed to examine the association of height with total cholesterol and hypercholesterolemia based on the nationally representative dataset of Korean adults. METHODS: The data of 13,701 adults aged ≥19 years who participated in the Korea National Health and Nutrition Examination Survey (2013-2015) were used in this nationwide population-based cross-sectional study. Hypercholesterolemia was defined as a serum total cholesterol level ≥ 240 mg/dL or use of lipid-lowering medications. Multivariable linear regression and logistic regression analyses were used to examine the association of height with mean total cholesterol level and odds ratios (ORs) of hypercholesterolemia. RESULTS: Approximately 17% of participants had hypercholesterolemia. Mean total cholesterol levels decreased in the higher quartile (Q) groups of height after adjusting for confounding variables including age, sex, body mass index, smoking status, alcohol consumption, physical activity, income, educational level, hypertension, and diabetes mellitus (P for trend = 0.035). After adjusting for these potential confounding variables, the adjusted ORs of hypercholesterolemia were significantly lower in the Q3 and Q4 groups than in the Q1 group; ORs decreased in the higher quartile groups of height (OR: 0.83, 95% confidence interval: 0.71-0.99 in Q3; 0.81, 0.69-0.95 in Q4, P for trend = 0.007). The association between height (Q4 vs. Q1-Q3) and hypercholesterolemia was stronger in men or individuals without hypertension or diabetes than in women or individuals with such diseases. CONCLUSIONS: Height is inversely associated with total cholesterol level and odds of hypercholesterolemia among Korean adults. Childhood environment related to short stature may be associated with hypercholesterolemia and cardiovascular health in adulthood.

Metabolic syndrome and risk of Parkinson disease: A nationwide cohort study.

BACKGROUND: The association of metabolic syndrome (MetS) with the development of Parkinson disease (PD) is currently unclear. We sought to determine whether MetS and its components are associated with the risk of incident PD using large-scale cohort data for the whole South Korean population. METHODS AND FINDINGS: Health checkup data of 17,163,560 individuals aged ≥40 years provided by the National Health Insurance Service (NHIS) of South Korea between January 1, 2009, and December 31, 2012, were included, and participants were followed up until December 31, 2015. The mean follow-up duration was 5.3 years. The hazard ratio (HR) and 95% confidence interval (CI) of PD were estimated using a Cox proportional hazards model adjusted for potential confounders. We identified 44,205 incident PD cases during follow-up. Individuals with MetS (n = 5,848,508) showed an increased risk of PD development compared with individuals without MetS (n = 11,315,052), even after adjusting for potential confounders including age, sex, smoking, alcohol consumption, physical activity, income, body mass index, estimated glomerular filtration rate, and history of stroke (model 3; HR, 95% CI: 1.24, 1.21-1.27). Each MetS component was positively associated with PD risk (HR, 95% CI: 1.13, 1.10-1.16 for abdominal obesity; 1.13, 1.10-1.15 for hypertriglyceridemia; 1.23, 1.20-1.25 for low high-density lipoprotein cholesterol; 1.05, 1.03-1.08 for high blood pressure; 1.21, 1.18-1.23 for hyperglycemia). PD incidence positively correlated with the number of MetS components (log-rank p < 0.001), and we observed a gradual increase in the HR for incident PD with increasing number of components (p < 0.001). A significant interaction between age and MetS on the risk of incident PD was observed (p for interaction < 0.001), and people aged ≥65 years old with MetS showed the highest HR of incident PD of all subgroups compared to those <65 years old without MetS (reference subgroup). Limitations of this study include the possibilities of misdiagnosis of PD and reverse causality. CONCLUSIONS: Our population-based large-scale cohort study suggests that MetS and its components may be risk factors of PD development.

Associations of mental health and sleep duration with menstrual cycle irregularity: a population-based study.

This study aimed to examine whether the characteristics of mental health and sleep duration, alone or in combination, are associated with menstrual cycle irregularity. This population-based, cross-sectional study analyzed the data from 4445 women aged 19-49 years, who participated in the Korea National Health and Nutrition Examination Survey 2010-2012. A structured questionnaire was used to assess mental health characteristics, sleep duration, and menstrual cycle irregularity. A multivariable logistic regression analysis was performed. High stress, depressive mood, and suicidal ideation were associated with increased risk of menstrual cycle irregularity after adjusting for confounding variables (odds ratio [95% confidence interval] = 1.33 [1.07-1.65], 1.56 [1.17-2.07], and 1.37 [1.01-1.87], respectively). Short sleep duration (≤ 5 h a day) was significantly associated with higher odds of severe menstrual cycle irregularity with menstrual interval of greater than 3 months (2.67 [1.35-5.27]). Participants with sleep duration of ≤ 5 h a day with psychological stress, depressive mood, or suicidal ideation had higher odds of menstrual cycle irregularity (1.96 [1.26-3.05], 2.86 [1.50-5.44], and 2.25 [1.18-4.29]). This study suggests positive associations of mental health problems and short sleep duration with menstrual cycle irregularity among Korean female adults. Therefore, strategies to deal with psychological stress, depressive mood, and sleep duration are needed for improving the reproductive health of women suffering from menstrual disturbances.

Sleep duration is associated with body fat and muscle mass and waist-to-height ratio beyond conventional obesity parameters in Korean adolescent boys.

While evidence has supported a strong association between sleep duration and obesity globally, results from studies of children and adolescents have been conflicting, and information about a sex-specific association has been limited. This study aimed to investigate the association of sleep duration with various parameters of obesity among South Korean adolescents. This population-based, cross-sectional study analysed the data obtained from the Korea National Health and Nutrition Examination Surveys (KNHANES) 2009 and 2010. Data of 990 adolescents were analysed. Sleep duration was based on a self-reported questionnaire. Body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), body fat percentage (BFP) and skeletal muscle index (SMI, appendicular skeletal muscle mass as a percentage of body weight) were assessed as parameters of obesity. Mean sleep duration in boys was associated inversely with BMI, WC, WHtR and BFP and positively with SMI. Proportions of the highest quartile of BMI, WC, WHtR and BFP and the lowest quartile of SMI increased significantly with increased sleep duration only in boys. Also, in boys, decreased sleep duration was associated significantly with the increased risk of the highest quartile of BMI, WC, WHtR and BFP and the lowest quartile of SMI, even after adjusting for confounding factors. However, in girls, there was no significant association between sleep duration and obesity parameters except WC. Periodic assessment of sleep duration in relation to body fat or muscle mass in male adolescents may be considered, especially in those who are at risk for obesity or related disorders.

Association between sleep duration and the prevalence of atopic dermatitis and asthma in young adults.

BACKGROUND: Sleep duration affects allergic diseases; however, this association requires further investigation. OBJECTIVE: To evaluate the association between sleep duration and the prevalence of atopic dermatitis and asthma in young Korean adults. METHOD: We analyzed data of 10,148 subjects (4,239 men; 5,909 women) aged 19-39 years from the Korean National Health and Nutrition Examination Survey 2008-2010. Self-reported sleep duration was categorized into five groups: ≤5h, 6h, 7h, 8h, and ≥9h. The prevalence of atopic dermatitis and asthma was examined based on a questionnaire and compared between participants from five sleep duration groups after adjusting for potential confounding factors, including model 1 [age], model 2 [model 1 + BMI, current smoking, current alcohol use, regular physical activity, household income, and serum 25(OH)D level], and model 3 [model 2 + stress levels]. RESULTS: In female participants, a higher risk of atopic dermatitis was associated with sleep duration ≤5 hours [odds ratio (OR): 1.665, 95% confidence interval (CI): 1.004-2.762; model 1], and ≥9 hours (OR, 1.746, 95% CI, 1.145-2.661; model 3), compared to a 7-hour sleep duration. Similarly, a higher risk of asthma was associated with sleep duration ≤5 hours and ≥9 hours (OR, 1.553, 95% CI, 1.023-2.359 and OR, 1.569, 95% CI, 1.048-2.349, respectively; model 3). In male participants, there was no significant association between sleep duration and the prevalence of atopic dermatitis or asthma. CONCLUSIONS: Sleep duration ≤5 and ≥9 hours may be a risk factor for atopic dermatitis and asthma in young female adults.

Trends in lipid profiles among South Korean adults: 2005, 2008 and 2010 Korea National Health and Nutrition Examination Survey.

BACKGROUND: This study aimed to investigate recent trends in the prevalence and parameters of dyslipidemia and rates of lipid-lowering medication use in Korean adults. Trends in lipid profiles in subjects with hypertension, diabetes or obesity were also studied. METHODS: Data from the Korea National Health and Nutrition Examination Survey in 2005, 2008 and 2010 were used in this study. A total of 17 009 subjects participated in this study. RESULTS: There was a declining trend in the prevalence of dyslipidemia and an increasing trend in the rates of use of lipid-lowering medication among Korean adults. In both men and women, the age-adjusted mean high-density lipoprotein cholesterol level linearly increased. There was a significantly decreasing trend in the age-adjusted mean triglycerides in women and age-adjusted mean lipid-related ratios in both sexes. The age-adjusted mean total cholesterol level showed a slightly increasing trend and the age-adjusted mean low-density lipoprotein cholesterol level was not changed in both sexes. These patterns persisted among subjects not taking lipid-lowering medication. The favorable trends were also observed in subjects with hypertension, diabetes and obesity. CONCLUSIONS: Our study showed favorable trends in the prevalence of dyslipidemia and in several lipid profiles among Korean adults.

Atopic dermatitis is associated with Caesarean sections in Korean adolescents, but asthma is not.

AIM: Studies on the associations between mode of delivery and allergic diseases have produced different results, and research has rarely been conducted in Asian countries such as South Korea. This study assessed the relationship between mode of delivery and atopic dermatitis and asthma in Korean adolescents. METHODS: Data collected from the Korea National Health and Nutrition Examination Survey between 2010 and 2011 were used. We included 1302 adolescents aged from 12 to 18 years, and multivariable logistic regression analysis was performed. RESULTS: The odds ratio (OR) of having atopic dermatitis in adolescents born by Caesarean section compared with vaginal delivery was 1.50, with a 95% confidence interval (95% CI) of 1.01-2.22, after adjusting for age and sex. The association remained significant after further adjustments for body mass index, breastfeeding and serum 25-hydroxyvitamin D level (OR = 1.61, 95% CI = 1.05-2.47) and when fat intake was added to those variables (OR = 1.80, 95% CI = 1.14-2.85). However, asthma was not associated with mode of delivery in any of the models. CONCLUSIONS: Atopic dermatitis in adolescents was associated with Caesarean delivery, which is common in South Korea. The findings suggest that the frequency of this practice should be reconsidered and that further research with longitudinal evaluation of relevant mechanisms is needed.