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

BACKGROUND: Several studies have suggested that breastfeeding has a positive effect on long-term obesity, diabetes, hypertension, and hyperlipidemia. This study aimed to examine maternal bone health, muscle mass, and obesity based on breastfeeding duration. METHODS: This study was based on the Korea National Health and Nutrition Examination Survey 2010–2011. We selected 2,027 elderly women by screening survey participants with a history of delivery. Multivariate logistic regression analyses were performed to estimate the odds ratios (ORs) of sarcopenia, osteoporosis, and obesity among four breastfeeding groups. RESULTS: The OR of sarcopenia significantly decreased with increasing breastfeeding duration (OR, 0.27; 95% confidence interval [CI], 0.11–0.65; P for trend <0.001), whereas the OR of obesity significantly increased with increasing breastfeeding duration (OR, 2.56; 95% CI, 1.43–4.60; P for trend=0.009) after adjusting for potential confounding variables. We also found a positive correlation between the duration since last delivery and sarcopenia. CONCLUSION: Our results suggest a negative correlation between prolonged breastfeeding and the prevalence of sarcopenia, and a positive correlation between prolonged breastfeeding and the prevalence of obesity. Further studies are needed to clarify the relationship between breastfeeding and sarcopenia in the future.
Aged ; Breast Feeding ; Confounding Factors (Epidemiology) ; Cross-Sectional Studies ; Female ; Humans ; Hyperlipidemias ; Hypertension ; Korea ; Logistic Models ; Mass Screening ; Nutrition Surveys ; Obesity ; Odds Ratio ; Osteoporosis ; Prevalence ; Sarcopenia

BACKGROUND: Cigarette smoking increases the risk of atherosclerosis, which often develops as vascular calcification on radiologic examinations. This study evaluated the relationship between smoking-related factors and incidental abdominal aorta calcification (AAC) detected by computed tomography (CT) among middle-aged and elderly men. METHODS: We assessed the abdominal CT findings of 218 men aged 40 to 81 years who underwent health checkups. The associations between smoking factors and AAC were analyzed using logistic regression analysis to adjust for confounding variables such as age, lifestyle factors, and chronic diseases. RESULTS: Adjusting for confounding variables, the risk of AAC was significantly increased in association with smoking for at least 20 years (adjusted odds ratio [AOR], 5.22; 95% confidence interval [CI], 1.82–14.93), smoking 10+ pack-years (10–20 pack-years: AOR, 4.54; 95% CI, 1.07–5.68; >20 pack-years: AOR, 5.28; 95% CI, 2.10–13.31), and a history of smoking (former smoker: AOR, 2.10; 95% CI, 1.07–5.68; current smoker: AOR, 5.05; 95% CI, 2.08–12.26). In terms of the daily smoking amount, even a low smoking level increased the risk of AAC. CONCLUSION: These findings suggest that smoking for 20+ years, smoking 10+ pack-years, and even a low level of smoking daily increases the likelihood of developing AAC. Clinicians should recommend that patients quit smoking and stress the importance of smoking duration when promoting health in middle-aged and elderly patients.
Aged ; Aorta, Abdominal ; Atherosclerosis ; Chronic Disease ; Confounding Factors (Epidemiology) ; Humans ; Life Style ; Logistic Models ; Male ; Odds Ratio ; Smoke ; Smoking ; Tomography, X-Ray Computed ; Vascular Calcification

BACKGROUND: Cancer survivors are at a higher risk of primary cancer recurrence and development of second primary cancer. In both cases, early disease detection is crucial. This cross-sectional study assessed cancer screening participation rates according to cancer history. METHODS: Data were obtained from the 2010–2012 Korea National Health and Nutrition Examination Survey for 12,500 participants. Of these, 624 cancer survivors were enrolled in this study. Sampling weights were applied to maintain the representativeness of the Korean adult population. RESULTS: Overall 2-year cancer screening rates prior to the survey in male and female cancer survivors were 59.9% and 73.7%, respectively, while opportunistic cancer screening rates were 33.5% and 52.1%, respectively. The odds ratios (95% confidence interval) of the overall cancer screening among the cancer survivors, compared to others, were 1.16 (0.79–1.72) in male and 1.78 (1.20–2.63) in female participants, after the adjustment for confounding variables. The odds ratios (95% confidence interval) for opportunistic cancer screening and National Cancer Screening Program among cancer survivors were 1.56 (1.07–2.27) and 0.80 (0.53–1.21) in males and 2.05 (1.46–2.88) and 0.66 (0.46–0.95) in females. CONCLUSION: Female cancer survivors showed a higher rate of overall and opportunistic cancer screening than did the male cancer survivors. Further efforts are required to improve cancer screening among male cancer survivors.
Adult ; Confounding Factors (Epidemiology) ; Cross-Sectional Studies ; Diagnosis ; Early Detection of Cancer ; Female ; Humans ; Korea ; Male ; Mass Screening ; Neoplasms, Second Primary ; Nutrition Surveys ; Odds Ratio ; Recurrence ; Survivors ; Weights and Measures

BACKGROUND: Exposure to secondhand smoke (SHS) has been shown to cause health problems. Recent studies demonstrated an association of SHS with depression and poor mental health. The urinary cotinine concentration (Ucot) is an objective indicator of exposure to SHS. In this study, we evaluated the association between depression and Ucot in adult non-smokers adults in Korea. METHODS: We analyzed the data of 3,417 adults, aged ≥19 years, who participated in the seventh Korea National Health and Nutrition Examination Survey (2016). The eligible subjects were non-smokers. Depression was evaluated using the Patient Health Questionnaire-9 (PHQ-9). The subjects were dichotomized into two groups: the high depressive symptom group (PHQ-9 ≥10 [n=185]) and the low depressive symptom group (PHQ-9 <10 [n=3,232]). The demographic, socioeconomic, and clinical characteristics of the subjects were retrieved from the survey data. Ucot was dichotomized into high-Ucot (≥10 ng/mL) and low-Ucot (<10 ng/mL). The Ucot and other characteristics were compared between the two groups. To adjust for confounding variables, we conducted a logistic regression analysis and determined the difference in Ucot between the two groups. RESULTS: After adjusting for confounders, the high depressive symptom group was found to be associated with high-Ucot (odds ratio, 1.824; 95% confidence interval, 1.020–3.262). Sex, education, socioeconomic status, marital status, occupational status, limitation of activity, and the presence of an underlying diseases (diabetes and dyslipidemia) had a significant effect on depression. CONCLUSIONS: This concluded that depression was associated with high urine cotinine level in adult non-smokers.
Adult ; Confounding Factors (Epidemiology) ; Cotinine ; Depression ; Education ; Employment ; Humans ; Korea ; Logistic Models ; Marital Status ; Mental Health ; Nutrition Surveys ; Social Class ; Tobacco ; Tobacco Smoke Pollution

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

BACKGROUND: Several contradictory studies exist on the relationship between raising grandchildren and the grandparent's health. The present study identified the association between raising grandchildren and depression among Korean grandparents.METHODS: The wave 1 (2006) and wave 2 (2008) databases of the Korean longitudinal study on aging (KLoSA) were analyzed. T-test and chi-square test were used to compare the demographics and health condition variable between the two groups based on the presence or absence of raising grandchildren. Logistic regression analysis, including demographics and health conditions, was conducted to identify the relationship between depression and raising grandchildren. Depression was assessed using the Center for Epidemiologic Studies Depression scale (CES-D-10).RESULTS: In all, 4,784 participants (4,636: not raising grandchildren; 148: raising grandchildren) were examined. Significantly lower CES-D-10 scores (3.34 vs. 4.35, P<0.001), and therefore, lower depression (25% vs. 39.9%, P<0.001) was found among grandparents raising grandchildren than those who did not raise grandchildren. After adjusting the confounding variables through logistic regression analysis, the odds ratio of depression when raising grandchildren was 0.57 (95% confidence interval=0.37–0.89), which indicates significant relevance.CONCLUSION: The results show lower depressive symptoms among grandparents raising grandchildren. Even after adjusting the variables, the results presented a lower risk of depression among them.
Adult ; Aging ; Confounding Factors (Epidemiology) ; Demography ; Depression ; Epidemiologic Studies ; Grandparents ; Humans ; Logistic Models ; Longitudinal Studies ; Odds Ratio