confounding variables.RESULTS: The BMD of the total femur and Ward's triangle were significantly different according to the potassium intake among men (P = 0.031 and P = 0.010, respectively). Women in the top tertile for potassium intake showed higher BMD than those in the bottom tertile at all measurement sites (all P < 0.05). Daily potassium intake was significantly related to a decreased risk of osteoporosis at the lumbar spine in postmenopausal women (odds ratios: 0.68, 95% confidence interval: 0.48-0.96, P trend = 0.031). However, the dietary potassium level was not related to the risk of osteoporosis in men.CONCLUSION: Current findings indicate that higher dietary potassium levels have a favorable effect on bone health and preventing osteoporosis in older Korean women.]]>
Absorptiometry, Photon ; Adult ; Bone Density ; Bone Diseases, Metabolic ; Calcium ; Confounding Factors (Epidemiology) ; Cross-Sectional Studies ; Epidemiology ; Female ; Femur ; Femur Neck ; Hip ; Humans ; Logistic Models ; Male ; Methods ; Nutrition Surveys ; Osteoporosis ; Population Surveillance ; Potassium ; Potassium, Dietary ; Prevalence ; Retrospective Studies ; Spine ; Vitamin D

OBJECTIVE: In this study, we evaluated the prevalence of allergic disease in offsprings delivered via the delivery modes of vaginal delivery vs. planned Cesarean section vs. Cesarean section with labor. METHODS: This study included 175 mother-neonate pairs from Severance Hospital who were enrolled in the Cohort for Childhood Origin of Asthma and allergic diseases study. Information regarding prenatal environmental factors, delivery, and diagnosis of allergic diseases was obtained from a questionnaire and medical record review. Patients with at least 3 years of follow-up data were included in this study. Results were adjusted for sex, birth weight, gestational age at birth, season of birth, neonatal intensive care unit admission, parity, breastfeeding, and maternal factors. RESULTS: A total of 175 offsprings were eligible for analysis. Among the subjects, 52.0% were delivered by vaginal delivery, 34.3% by planned Cesarean section, and 16.6% by Cesarean section with labor. Fifty-nine offsprings (33.7%) were diagnosed with allergic disease at a median age of 1 year (range 0.5–3 years). The prevalence of allergic disease was not associated with delivery mode after adjusting for confounding variables. Time period from membrane rupture to delivery, duration of the active phase, and the beginning of the pelvic division prior to Cesarean section were not associated with allergic disease development in offsprings. CONCLUSION: Cesarean section, irrespective of the occurrence of labor before surgery, did not increase the prevalence of allergic disease in infants up to 3 years of age.
Asthma ; Birth Weight ; Breast Feeding ; Cesarean Section* ; Cohort Studies ; Confounding Factors (Epidemiology) ; Diagnosis ; Female ; Follow-Up Studies ; Gestational Age ; Humans ; Infant ; Infant, Newborn ; Intensive Care, Neonatal ; Medical Records ; Membranes ; Parity ; Parturition ; Pregnancy ; Prevalence* ; Rupture ; Seasons

PURPOSE: This study aims to investigate the effects of smoking on the development of placenta-associated syndromes, including preeclampsia, abruptio placentae, and placenta previa, which share the common pathophysiology of vascular compromise of the placenta. METHODS: A total of 966,629 pregnancies identified from the Korean National Insurance Claims Database and the National Health Information Database were analyzed from 2010 to 2014. The adjusted odds ratio and attributable risk of smoking for the development of placenta-associated syndromes, such as preeclampsia, placenta previa, and abruptio placentae, were analyzed. Maternal age, alcohol consumption, exercise habit, and economic status were controlled as confounding variables. A binary logistic regression model was used, and simple and multiple logistic regression analyses were performed. RESULTS: Among 966,629 pregnancies, 11.86% of women were ever smokers. Ever smokers had a higher risk of developing placenta previa (adjusted odds ratio, 1.23; 95% confidence interval [CI], 1.18–1.29; adjusted attributable risk, 18.70%). The adjusted odds ratio of developing placenta-associated syndromes in ever smokers compared to nonsmokers over the age of 35 years with a low economic status was 1.32 (95% CI, 1.18–1.47), with an adjusted attributable risk of 23.95%. CONCLUSION: The risk of developing placenta-associated syndromes, such as preeclampsia, placenta previa, and abruptio placentae, is high in ever smokers. Pregnant ever smokers who are >35 years and belong to the lower one-third of the economic division require special care to prevent the development of placenta-associated syndromes.
Abruptio Placentae ; Alcohol Drinking ; Confounding Factors (Epidemiology) ; Female ; Humans ; Insurance ; Korea ; Logistic Models ; Maternal Age ; Odds Ratio ; Placenta ; Placenta Previa ; Pre-Eclampsia ; Pregnancy ; Smoke ; Smoking

BACKGROUND: Chronic kidney disease (CKD)-mineral and bone disorder (MBD) and fracture risk are both closely related to declining renal function. Controlling hyperphosphatemia with phosphate binders is a basic principle of CKD-MBD treatment. The aim of this study was to identify differences in fracture risk between pre-dialysis CKD patients and end-stage renal disease (ESRD) on dialysis, and to evaluate the effects of phosphate binders on fracture risk in ESRD patients. METHODS: Data from a total of 89,533 CKD patients comprising CKD diagnosis, dialysis, fracture history, and phosphate binder prescription history from 2012 to 2016 were retrieved from the Health Insurance Review and Assessment Service Database. Multivariate Cox regression analyses were performed to identify whether dialysis or phosphate binders were associated with an increased fracture risk. RESULTS: Overall, the rate of fractures in pre-dialysis CKD patients was 74 per 1,000 patient-years, while that in dialysis patients was 84 per 1,000 patient-years. The risk of fracture in ESRD patients was higher than pre-dialysis CKD patients (hazard ratio, 1.16; 95% confidence interval, 1.12–1.21; P < 0.001) after adjusting for confounding variables. In addition, the fracture risk in patients who were not taking phosphate binders was 20.0% higher compared to ESRD patients taking phosphate binders. CONCLUSION: Fractures were more prevalent in ESRD patients on dialysis than pre-dialysis CKD patients. Use of phosphate binders was associated with a lower fracture risk in ESRD patients.
Cohort Studies ; Confounding Factors (Epidemiology) ; Diagnosis ; Dialysis ; Humans ; Hyperphosphatemia ; Insurance, Health ; Kidney Failure, Chronic ; Prescriptions ; Renal Insufficiency, Chronic

OBJECTIVES: The purpose of this study was to investigate the association between the components of metabolic syndrome (MetS) (waist circumference, hyperglycemia, hypertriglyceridemia, low levels of high-density lipoprotein cholesterol, and hypertension) and periodontitis in Korean adults aged 35–79 years. METHODS: In this study, data from the Sixth Korean National Health and Nutrition Examination Survey (KNHANES, 2013–2015) were analyzed. Among the 22,948 participants of the Sixth KNHANES, 8,314 participants, who were aged 35–79 years and had completed all systemic and oral health examinations and questionnaires, were included in this study. Confounding variables associated with the demographics and socioeconomic status and systemic and oral health-related behaviors were age, gender, household income, the educational level, smoking and drinking habits, the physical activity status, and frequency of daily toothbrushing. The independent variables were components of MetS, and the dependent variable was periodontitis. RESULTS: Periodontitis was diagnosed in 37.0% of the participants. The incidence of periodontitis among participants with MetS was 47.9%. The incidences of periodontitis among participants with three, four, and five components of MetS were 44.8%, 50.0%, and 56.2%, respectively. The odds ratio (OR) for periodontitis among participants with MetS was 1.43 (95% confidence interval [CI]: 1.27–1.61). The participants with three, four, and five components of MetS showed a significantly higher OR for periodontitis than those with no components of MetS (three components, OR=1.18, 95% CI: 1.02–1.36; four components, OR=1.34, 95% CI: 1.14–1.59; five components, OR=1.68, 95% CI: 1.29–2.20). CONCLUSIONS: A higher number of components of MetS augments the OR of periodontitis.
Adult ; Cholesterol ; Confounding Factors (Epidemiology) ; Demography ; Drinking ; Epidemiology ; Family Characteristics ; Humans ; Hyperglycemia ; Hypertriglyceridemia ; Incidence ; Lipoproteins ; Motor Activity ; Nutrition Surveys ; Odds Ratio ; Oral Health ; Periodontitis ; Smoke ; Smoking ; Social Class ; Toothbrushing

PURPOSE: This study examined the changes in the nutrient intake and the prevalences of obesity and metabolic syndrome according to the eating alone behavior in middle-aged men and women. METHODS: The data from the 2013 ~ 2017 Korean National Health and Nutrition Examination Survey were analyzed. A total of 7,728 adults (3,404 male, 4,324 female) aged 40 ~ 64 years old were included. The subjects were classified into three groups according to the number of times eating alone per day (0, 1 ~ 2, and 3 times/day). Dietary data were collected by a 1-day 24-h recall. The nutrient intakes were compared among the three groups. Survey logistic regression analyses were conducted to examine the association of the eating alone behavior with obesity and metabolic syndrome, adjusting for the related confounding variables. RESULTS: In men, eating alone was associated significantly with a lower intake of potassium (p-for-trend = 0.048) and lower intake of calories from protein (p-for-trend = 0.04). In women, the proportion of subjects consuming energy less than 75% of the estimated energy requirement (p = 0.001) and less than the estimated adequate requirement of riboflavin (p < 0.001) differed significantly according to the eating alone behavior. The eating alone behavior was positively associated with an increased risk of developing metabolic syndrome (p-for-trend = 0.033), increased blood pressure (p-for-trend < 0.001), and increased waist circumference (p-for-trend = 0.004). On the other hand, in women, however, the eating alone behavior was associated with a decreased risks of developing obesity (p-for-trend = 0.02). No association was found between the eating alone behavior and the risk of metabolic syndrome in women. CONCLUSION: These results suggest that the eating alone behavior is a risk factor for the development of metabolic syndrome in middle-aged Korean men.
Adult ; Blood Pressure ; Confounding Factors (Epidemiology) ; Eating ; Female ; Hand ; Humans ; Logistic Models ; Male ; Nutrition Surveys ; Obesity ; Potassium ; Prevalence ; Riboflavin ; Risk Factors ; Waist Circumference

BACKGROUND: The seropositivity rate of hepatitis B surface antigen (anti-HBs) antibodies is known to be ≥95% after hepatitis B virus vaccination during infancy. However, a low level or absence of anti-HBs in healthy children is discovered in many cases. Recent studies in adults reported that a reduced anti-HBs production rate is related to obesity.PURPOSE: To investigate whether body mass index (BMI) affects anti-HBs levels in healthy children following 3 serial dose vaccinations in infancy.METHODS: We recruited 1,200 healthy volunteers aged 3, 5, 7, or 10 years from 4-day care centers and 4 elementary schools. All subjects completed a questionnaire including body weight, height, and vaccine type received. Levels of serum hepatitis B surface antigen (HBsAg) and anti-HBs in all subjects were analyzed using electrochemiluminescence immunoassay. The standardized scores (z score) for each sex and age were obtained using the lambda-mu-sigma method in the 2017 Korean National Growth Charts for children and adolescents.RESULTS: Our subjects (n=1,200) comprised 750 males (62.5%) and 450 females (37.5%). The overall anti-HBs seropositivity rate was 57.9% (695 of 1,200). We identified significant differences in mean BMI values between seronegative and seropositive groups (17.45 vs. 16.62, respectively; P<0.001). The anti-HBs titer was significantly decreased as the BMI z score increased adjusting for age and sex (B=-15.725; standard error=5.494; P=0.004). The probability of anti-HBs seropositivity based on BMI z score was decreased to an OR of 0.820 after the control for confounding variables (95% confidence interval, 0.728–0.923; P=0.001).CONCLUSION: There was a significant association between anti-HBs titer and BMI z score after adjustment for age and sex. Our results indicate that BMI is a potential factor affecting anti-HBs titer in healthy children.
Adolescent ; Adult ; Antibodies ; Body Mass Index ; Body Weight ; Child ; Confounding Factors (Epidemiology) ; Female ; Growth Charts ; Healthy Volunteers ; Hepatitis B Surface Antigens ; Hepatitis B virus ; Hepatitis B ; Hepatitis ; Humans ; Immunoassay ; Male ; Methods ; Obesity ; Vaccination

BACKGROUND: This study evaluated the association between nicotine dependence and depressive mood in patients who visited a secondary hospital for smoking cessation treatment.METHODS: From March 2016 to February 2017, a total of 48 patients who visited the smoking cessation clinic of a secondary hospital in Seoul were surveyed through questionnaires. Nicotine dependence was assessed by the Fagerström Test for Nicotine Dependence. The Beck Depression Inventory (BDI) was used to assess depressive mood.RESULTS: The mean BDI score was positively associated with nicotine dependence (P=0.01). In multivariable logistic regression analysis, increasing BDI was associated with higher odds (1.21, 95% confidence interval; 1.02–1.44) of high nicotine dependence after adjusting for all confounding variables.CONCLUSION: Depressive mood was positively associated with nicotine dependence among patients who visited a smoking cessation clinic. Consideration of depressive mood in smoking cessation treatment may be helpful for smoking cessation among patients with a willingness to quit smoking.
Confounding Factors (Epidemiology) ; Depression ; Humans ; Logistic Models ; Nicotine ; Seoul ; Smoke ; Smoking Cessation ; Smoking ; Tobacco Use Disorder

BACKGROUND: The ankle-brachial index (ABI) is a simple, noninvasive clinical test that is useful in the diagnosis of peripheral artery disease (PAD). The borderline ABI value is 0.91–0.99 and has also been reported in endothelial dysfunction and preclinical PAD. We investigated the relationship between resting heart rate as a surrogate marker of autonomic balance and borderline ABI in apparently healthy individuals.METHODS: We evaluated the association between resting heart rate and borderline ABI in 618 participants (348 male and 270 female) in a health examination program. The odds ratios for borderline ABI were calculated using a multivariable logistic regression analysis after adjusting for confounding variables across heart rate quartiles (Q1≤56, Q2=57–62, Q3=63–68, and Q4≥69 beats/min).RESULTS: The overall prevalence of borderline ABI was 13.9%. The age- and sex-adjusted resting heart rate was significantly higher in the borderline ABI group than in the control group (66.9±0.9 vs. 63.0±0.4 beats/min, P < 0.001). The odds ratios (95% confidence intervals) for the borderline ABI in each heart rate quartile were 1.00, 1.04 (0.43–2.52), 1.69 (0.73–3.93), and 3.52 (1.55–7.97) after adjusting for age, sex, smoking status, alcohol intake, regular exercise, body mass index, systolic blood pressure, fasting plasma glucose level, triglyceride level, high-density lipoprotein-cholesterol level, white blood cell count, C-reactive protein level, uric acid level, γ-glutamyltransferase level, hypertension medication, diabetes medication, and dyslipidemia medication.CONCLUSION: These findings indicate that a higher resting heart rate is independently associated with borderline ABI.
Ankle Brachial Index ; Biomarkers ; Blood Glucose ; Blood Pressure ; Body Mass Index ; C-Reactive Protein ; Confounding Factors (Epidemiology) ; Diagnosis ; Dyslipidemias ; Fasting ; Heart Rate ; Heart ; Humans ; Hypertension ; Leukocyte Count ; Logistic Models ; Male ; Odds Ratio ; Peripheral Arterial Disease ; Prevalence ; Smoke ; Smoking ; Triglycerides ; Uric Acid

BACKGROUND: Colon cancer is one of the main causes of mortality. Early adenomatous colon polyp is a precursor of colon cancer through the ‘adenomacarcinoma sequence.’ Epidemiological studies suggest that the neutrophil to lymphocyte ratio can be one of useful inflammatory markers in clinical settings. This study aimed to evaluate the association between neutrophil to lymphocyte ratio and development of early adenomatous colon polyps.METHODS: This cross-sectional study retrospectively examined 960 middle-aged and elderly individuals aged ≥45 years who underwent colonoscopy in a health examination program. Multivariate logistic regression was used to analyze the association between neutrophil to lymphocyte ratio and development of early adenomatous colon polyps.RESULTS: Among the 960 subjects, the prevalence of early adenomatous polyps was 20.7% (n=199). The mean age, body mass index, number of current smokers, white blood cell count, triglyceride level, and number of subjects receiving hypolipidemic drugs were higher in the group with early adenomatous polyps than in the multivariate analysis, the odds ratio (95% confidence interval) for the development of early adenomatous polyps was 1.23 (1.01–1.50) with neutrophil to lymphocyte ratio increment after adjusting the confounding variables (P=0.037).CONCLUSION: We found that the neutrophil to lymphocyte ratio was associated with the development of early adenomatous colon polyps among middle-aged and elderly individuals. Accordingly, this result suggests that regular monitoring of early adenomatous colon polyps may be useful among individuals with a higher neutrophil to lymphocyte ratio.
Adenomatous Polyps ; Aged ; Body Mass Index ; Colon ; Colonic Neoplasms ; Colonic Polyps ; Colonoscopy ; Confounding Factors (Epidemiology) ; Cross-Sectional Studies ; Epidemiologic Studies ; Humans ; Hypolipidemic Agents ; Korea ; Leukocyte Count ; Logistic Models ; Lymphocytes ; Middle Aged ; Mortality ; Multivariate Analysis ; Neutrophils ; Odds Ratio ; Polyps ; Prevalence ; Retrospective Studies ; Triglycerides