Joong-Myung Choi

Relationship Between Body Mass Index and Early Menarche of Adolescent Girls in Seoul

Objectives The object of this study was to determine the relationship between body mass index (BMI) and early menarche in adolescent girls in Seoul. Methods A retrospective study was conducted with 144 middle school students in Seoul who provided informed consent. We measured their body composition, and used the questionnaire survey method for data collection from November to December 2008. Past elemental body composition data were collected from elementary school health records of first year of middle school. Results The early menarcheal group was taller and heavier than the late menarcheal group (p<0.05 from 8-12 years old). The body fat percentage (%), BMI were higher in the early menarcheal girls than the late-menarcheal girls (p<0.05, age at 13). In the result of multiple logistic regression, the BMI at the age of 8 and 9 was associated with early menarche after adjusting for birth weight, breast feeding and age at menarche of the mother (BMI at the age of 8: p for trend=0.01, BMI at the age of 9: p for trend=0.04). An increase in BMI from 7 to 8 year was associated with early menarche after adjusting for birth weight, breast feeding, age at menarche of the mother (p for trend=0.048). Conclusions The BMI at the age of 8 and 9 was associated with the early menarche of girls and increase in BMI from 7 to 8 year was associated with the early menarche of girls. These results suggest that BMI and increase in BMI before menarche cause early menarche. Although this study does not represent all Korean adolescent girls, it is one of the few studies that have investigated the temporal relationship between BMI and early menarche.

Clinical association between non-alcoholic fatty liver disease and the development of hypertension.

Non‐alcoholic fatty liver disease (NAFLD) is getting an increasing attention for its clinical implications on cardiovascular disease (CVD). However, epidemiologic data are not so evident to sustain the causative association between NAFLD and hypertension, the major cause of CVD. Accordingly, we designed this study to investigate the clinical association between NAFLD and the development of hypertension.

Anthropometric Changes in Children and Adolescents From 1965 to 2005 in Korea

The aim of this study was to assess the secular growth changes in Korean children and adolescents during the last four decades. In 2005, 68,790 boys and 62,557 girls were recruited for this study across the nation in 2005. Anthropometric data (weight, height, etc.) were measured. We compared the results of previous nationwide growth studies with this study. The results of this survey indicate that the growth and developmental status of Korean children and adolescents has been changed substantially compared with those in 1965, 1975, 1984, and 1997. The data presented in this study show a distinct secular increase in growth in body height and weight of Korean children and adolescents spanning this period. A nationwide survey every 5 years would be beneficial to establish a reference standard for the growth of children and adolescents according to the socioeconomic, environmental, and nutritional changes.

Relationship Between Socioeconomic Variables and Obesity in Korean Adolescents

Background Despite the importance of obesity and its association with socioeconomic status, little is known about this condition in Korean adolescents. We examined the relationship between obesity in Korean adolescents and several socioeconomic variables and compared the association of obesity with conventional and subjective indicators of socioeconomic status. Methods The study comprised 60 643 Korean adolescents aged 12 to 18 years who participated in the 2007 Korea Youth Risk Behavior Web-Based Survey. The dependent variable, obesity, and the independent variables of parental education levels, family affluence scale, subjective family economic status, and subjective school achievement were collected by using a self-administered anonymous questionnaire. Data on behavioral and psychological characteristics were also collected and used as confounding factors. Multivariate logistic regression was conducted to identify associations between socioeconomic status and obesity. Results In the descriptive analysis, adolescents with low parental education, low family affluence level, low subjective family economic status, and low subjective school achievement were more likely to be obese. However, after controlling for other risk factors in multivariate analysis, only the associations with subjective family economic status and subjective school achievement remained statistically significant. Conclusions Our results provide further evidence that the prevalent pattern of obesity in Korean adolescents—i.e., the inverse relationship between obesity and socioeconomic status—is similar to that in developed countries. In addition, these findings support the hypothesis that, as compared with objective socioeconomic status, subjective social status is more closely related to obesity.

The Association between Uric Acid and Chronic Kidney Disease in Korean Men: A 4-Year Follow-up Study

There have been many studies between serum uric acid (UA) and chronic kidney disease (CKD). However, as far as we know, little research has been done to examine the prospective association between serum UA and development of CKD in Korean men. This prospective cohort study was performed using 18,778 men who participated in a health checkup program both on January, 2005 and on December, 2009. CKD was defined as an estimated glomerular filtration rate < 60 mL/min per 1.73 m2. The odds ratio (OR) from binary logistic regressions for the development of CKD was determined with respect to the quintiles grouping based on serum UA. During 74,821.4 person-years of follow-up, 110 men were found to develop CKD. The OR for the development of CKD increased as the quintiles for baseline serum UA levels increased from the first to fifth quintiles (1.00 vs 1.22, 1.19, 2.59, and 3.03, respectively, p for linear trend < 0.001) after adjusting for covariates. The adjusted OR comparing those participants with hyperuricemia ( ≥ 7.0 mg/dL) to those with normouricemia ( < 7.0 mg/dL) was 1.96 (1.28-2.99). Elevated serum UA levels were independently associated with increased likelihood for the development of CKD in Korean men (IRB number: KBC10034).

The clinical availability of non alcoholic fatty liver disease as an early predictor of the metabolic syndrome in Korean men: 5-Year's prospective cohort study

OBJECTIVES There were many studies for the clinical association between non alcoholic fatty liver disease (NAFLD) and metabolic syndrome (MetS). However, while most of studies have focused on the unilateral effects of MetS on NAFLD, studies for reverse association were comparatively rare. Therefore, we carried out a prospective cohort study to evaluate the longitudinal effects of NAFLD on the development of MetS according to the degree of NAFLD. PATIENTS AND METHODS A total of 46,874 men, who had participated in a medical health check-up program in 2005, were enrolled in this study. Out of them, a Mets-free cohort of 11,926 without excluding conditions was followed up until 2010. All participants were classified into 3 groups by their NAFLD status (normal, mild, moderate to severe). The baseline values of metabolic components and the development rates of MetS were compared according to the degree of NAFLD. Cox proportional hazards model was used to measure the hazard ratios (HRs) for MetS according to the degree of NAFLD. RESULTS During 41,912.1 person-years of follow-up, 1861 incident cases of MetS developed between 2006 and 2010. Even after adjusting for multiple covariates, the HRs (95% CI) for MetS were higher in the mild group (1.49; 1.30-1.70) and moderate to severe group (2.00; 1.46-2.73) compared to normal group, respectively (P for trend <0.001). These associations were apparent in the clinically relevant subgroup analyses. CONCLUSIONS NAFLD was independent risk factor for MetS during the 5-yr follow-up period.

Blood cadmium levels are associated with a decline in lung function in males

BACKGROUND Cadmium exposure was found to cause a decline in lung function among the general population, but these findings were limited to smokers and gender differences were not explored. OBJECTIVES To examine the relationship between cadmium and chronic obstructive pulmonary disease (COPD) according to gender and smoking status in Korea. METHODS Cross-sectional data from the Korean National Health and Nutrition Examination Survey from 2008 to 2011 were analyzed. COPD was defined by a pre-bronchodilator forced expiratory volume in 1s divided by forced vital capacity of <0.70. A logistic regression model was used to elucidate the association between blood cadmium levels and COPD according to gender and smoking status. RESULTS Among 3861 eligible participants, 3622 were included in the analysis. The prevalence of COPD demonstrated an increasing trend in males (P for trend<0.001), but not in females (P for trend=0.67). After adjusting for covariates, a higher blood cadmium level, but within the normal range, was associated with COPD in males, including those who had never-smoked (P for trend <0.001 and P for trend=0.008). However, a higher blood cadmium level was not significantly associated with COPD in females, including those who had never smoked (P for trend=0.39 and P for trend=0.43). CONCLUSIONS A higher blood cadmium level, within the normal range, was associated with COPD in males, including those who had never smoked. However, there was no significant association between blood cadmium levels and COPD in females.

Clinical significance of urinary vascular endothelial growth factor and microvessel density in patients with renal cell carcinoma.

OBJECTIVES To investigate the urinary vascular endothelial growth factor (VEGF) levels from patients with renal cell carcinoma (RCC). Neovascularization, an essential event for the growth of solid tumors, is regulated by a number of angiogenic factors. VEGF is thought to exert potent angiogenic activity. METHODS Urine samples were obtained before radical nephrectomy from 27 patients with RCC and 10 control subjects with no evidence of cancer or inflammatory disease. VEGF was measured by enzyme-linked immunosorbent assay in the urine and corrected according to the 24-hour urine concentration of creatinine. The microvessel density was measured by immunohistochemical staining with CD31 monoclonal antibody. Nuclear morphometry was performed by photomicroscopy. RESULTS The corrected urinary VEGF levels in patients with RCC were much higher than those in the normal control group (P = 0.039) and were more elevated in patients with higher stages of RCC (Stages III and IV versus Stages I and II; P = 0.024). A tendency was also noted for the VEGF levels to be higher according to cell grade. However, no statistical correlation was found between the corrected urinary VEGF and age, sex, tumor size, cell type, microvessel density, platelet count, or hemoglobin. The nuclear area was higher with more advanced-stage tumors (P = 0.043) and tended to increase according to the tumor cell grade. CONCLUSIONS The results of this study indicate that urinary VEGF levels are increased in patients with RCC. However, they may not reflect the underlying angiogenic activity, and it may be that other angiogenic factors play a more prominent role.

The Relation of Menarcheal Age to Anthropometric Profiles in Korean Girls

The aim of this study was to represent the trend of early menarche and to assess the association of age at menarche with anthropometric profiles of Korean children and adolescents. A cross sectional survey was conducted with 13,371 girls aged 10 to 18 yr, recruited nationwide from April, 2005 to March, 2006. Height, weight and waist circumference of the subjects were measured; and the subjects self-reported their ages at menarche. We found that the menarcheal girls were taller (P<0.05 for the girls between 10 and 14 yr) and heavier (P<0.05 for the girls between 10 and 18 yr) than non-menarcheal ones. Menarcheal girls also showed higher body mass index (BMI), and greater waist circumference than non-menarcheal ones. Significant differences were represented according to the age at menarche in terms of BMI, waist circumference, % body fat mass, waist hip ratio and neck circumference as well as height and weight (P<0.05). In conclusion, girls who matured early were taller and heavier in early adolescence than those who matured later.

The Epidemiology and Economic Burden of Clostridium difficile Infection in Korea

The prevalence of Clostridium difficile infection and the associated burden have recently increased in many countries. While the main risk factors for C. difficile infection include old age and antibiotic use, the prevalence of this infection is increasing in low-risk groups. These trends highlight the need for research on C. difficile infection. This study pointed out the prevalence and economic burden of C. difficile infection and uses the representative national data which is primarily from the database of the Korean Health Insurance Review and Assessment Service, for 2008–2011. The annual economic cost was measured using a prevalence approach, which sums the costs incurred to treat C. difficile infection. C. difficile infection prevalence was estimated to have increased from 1.43 per 100,000 in 2008 to 5.06 per 100,000 in 2011. Moreover, mortality increased from 69 cases in 2008 to 172 in 2011. The economic cost increased concurrently, from