Kirang Kim

Body Fat Percentile Curves for Korean Children and Adolescents: A Data from the Korea National Health and Nutrition Examination Survey 2009-2010

A valid assessment of obesity in children and adolescents is important due to significant change in body composition during growth. This study aimed to develop percentile curves of body fat and fat free mass using the Lambda, Mu, and Sigma method, and to examine the relationship among body mass index (BMI), fat mass and fat free mass in Korean children and adolescents, using the Korea National Health and Nutrition Examination Survey (KNHANES) 2009-2010. The study subjects were 834 for boys and 745 for girls aged between 10 and 18 yr. Fat mass and fat free mass were measured by dual-energy x-ray absorptiometry. The patterns of development in body fat percentage, fat mass and fat free mass differed for boys and girls, showing a decreased fat mass with an increased fat free mass in boys but gradual increases with age in girls. The considerable proportion of boys and girls with relatively normal fat mass appeared to be misclassified to be at risk of overweight based on the BMI criteria. Therefore, the information on the percentiles of body fat and fat free mass with their patterns would be helpful to complement assessment of overweight and obesity based on BMI for Korean children and adolescents.

The relationship of dietary sodium, potassium, fruits, and vegetables intake with blood pressure among Korean adults aged 40 and older

BACKGROUND/OBJECTIVES The inverse relationships of combined fruits and vegetables intake with blood pressure have been reported. However, whether there are such relationships with salty vegetables has rarely been investigated in epidemiologic studies. We evaluated the relation of combined and separate intake of fruits, vegetable intakes, and salty vegetables, as well as sodium and potassium, with blood pressure among the middle-aged and elderly populations. SUBJECTS/METHODS The present cross-sectional analysis of a prospective cohort baseline survey was performed with 6,283 subjects (2,443 men and 3,840 women) and free of hypertension, diabetes, cardiovascular diseases, and cancer. Dietary data were collected by trained interviewers using food frequency questionnaire. RESULTS The significantly inverse linear trend of diastolic blood pressure (DBP) was found in fruits and non-pickled vegetables (81.2 mmHg in the lowest quintile vs 79.0 mmHg in the highest quintile, P for trend = 0.0040) and fruits only (80.9 mmHg in the lowest quintile vs 79.4 mmHg in the highest quintile, P for trend = 0.0430) among men. In contrast, sodium and sodium to potassium ratio were positively related with blood pressure among men (DBP, 78.8 mmHg in the lowest quintile vs 80.6 mmHg in the highest quintile, P for trend = 0.0079 for sodium; DBP, 79.0 mmHg in the lowest quintile vs 80.7 mmHg in the highest quintile, P for trend = 0.0199 and SBP, 123.8 mmHg in the lowest quintile vs 125.9 mmHg in the highest quintile for sodium/potassium). Kimchies consumption was positively related to DBP for men (78.2 mmHg in the lowest quintile vs 80.9 mmHg in the highest quintile for DBP, P for trend = 0.0003). Among women, these relations were not found. CONCLUSION Fruits and/or non-pickled vegetables may be inversely, but sodium, sodium to potassium, and Kimchies may be positively related to blood pressure among men.

The impact of nutritional policy on socioeconomic disparity in the unhealthy food intake among Korean adolescents.

The objectives of this study were to examine the trend in unhealthy food intake by socioeconomic position (SEP) and to determine whether the governments nutritional policies affect socioeconomic disparity in the food intake among adolescents. Data were from the six independent cross-sectional survey data (2006-2011) of Korea Youth Risk Behavior Web-based Survey and included 445,287 subjects aged 12-18 years. The unhealthy food intake was assessed by food frequency intake and SEP was evaluated with the family affluence scale. We observed that unhealthy food intakes decreased through the years, showing the apparent decline when nutritional policies focusing on the restriction of unhealthy foods were implemented, and the trend was all same in the different SEP groups. The pattern of unhealthy food intakes by SEP has changed before and after implementation of the policies. The intakes of carbonated beverages, fast food, and confectioneries were higher in the higher SEP group before implementation of the policies but the difference was not shown after implementation of the policies. The intake of instant noodles was consistently higher in the lower SEP group. The risk of frequent consumption of unhealthy foods was generally more decreased through the years in the higher SEP group than the lower SEP group. In conclusion, this study found the positive effect of nutritional policy on unhealthy food intake among adolescents and the high SEP group appeared to undergo greater desirable changes in dietary behaviors after implementation of nutritional policies than the low SEP group.

Interactions of single nucleotide polymorphisms with dietary calcium intake on the risk of metabolic syndrome

BACKGROUND Gene-nutrient interactions may be important in modulating susceptibility to metabolic disorders. OBJECTIVES The objectives of this study were to assess the association of dietary calcium intake with the risk of metabolic syndrome and to investigate the interaction effects between dietary calcium intake and candidate gene polymorphisms. DESIGN Subjects were participants in the Korea Association Resource project, which was initiated in 2007 as a large-scale, genomewide association analysis. A total of 8031 subjects were included in the study. Associations were assessed by using multivariable-adjusted logistic regression analyses. RESULTS High calcium intake appeared to be associated with a low risk of metabolic syndrome after covariates in both men (P-trend = 0.03) and women (P-trend = 0.0002) were controlled for. Among 27 single nucleotide polymorphisms (SNPs) selected as possible candidate gene polymorphisms affecting the risk of metabolic syndrome, 3 SNPs [rs6445834 in Rho guanine nucleotide exchange factor 3 (ARHGEF3), rs10850335 in T-box 5 (TBX5), rs180349 in BUD13 homolog (Saccaromyces cerevisiae) (BUD13)] showed significant interaction effects with calcium intake tertiles or sufficiency in both men and women. Subjects with major allele homozygotes of these gene polymorphisms and high calcium intakes generally had a lower risk of metabolic syndrome than did those with minor allele homozygotes and low calcium intakes. CONCLUSION Dietary calcium intake appears to be inversely associated with the risk of metabolic syndrome and may modulate susceptibility to the syndrome in subjects who are minor allele carriers of rs6445834 in ARHGEF3, rs10850335 in TBX5, or rs180349 in BUD13.

Relation of serum 25-hydroxyvitamin D status with skeletal muscle mass by sex and age group among Korean adults.

The objective of this study was to examine whether high serum 25-hydroxyvitamin D (25(OH)D) concentration was associated with high skeletal muscle mass, taking into account the effects of sex and age among the participants of the Korea National Health and Nutrition Examination Survey (KNHANES) aged 40 years or older. This was a cross-sectional study using data from the 2009 to 2010 KNHANES; a total of 8406 subjects (3671 men and 4735 women) were included. The appendicular skeletal muscle mass index (ASMMI, kg/m2) was estimated to measure the skeletal muscle mass. Hypovitaminosis was classified when the level of serum 25(OH)D was <20 ng/ml. The general linear model adjusted for confounding factors was used to determine differences in means of ASMMI by 25(OH)D status. The mean values of ASMMI were higher for men when compared with women. Women had a greater proportion of hypovitaminosis (71·1%) compared with men (53·2%). After adjusting for multiple factors, men were seen to have significant differences in ASMMI based on 25(OH)D status regardless of age, showing a lower mean value of ASSMI in those with hypovitaminosis. However, there was no difference in ASMMI by 25(OH)D status among women in both younger and older age groups. In conclusion, we found that there might be a positive relationship between 25(OH)D and skeletal muscle mass in men, indicating that interventions to improve 25(OH)D levels that are aimed at increasing muscle mass could be beneficial for men with more rapid decreased rate of skeletal muscle mass.

Reference Values of Skeletal Muscle Mass for Korean Children and Adolescents Using Data from the Korean National Health and Nutrition Examination Survey 2009-2011.

Background Skeletal muscle mass (SMM) plays a crucial role in systemic glucose metabolism. Objective To obtain reference data on absolute and relative values of SMM for Korean children and adolescents. Methods Cross-sectional results from 1919 children and adolescents (1024 boys) aged 10–18 years that underwent dual-energy X-ray absorptiometry (DXA) during the Korean National Health and Nutrition Examination Survey 2009–2011 were analyzed. SMMs were evaluated as follows; absolute SMM (appendicular skeletal muscle mass [ASM]) and relative SMMs, namely, height-adjusted skeletal muscle index (SMI; ASM/height2), %SMM (ASM/weight x 100), and skeletal muscle-to-body fat ratio (MFR; ASM/body fat mass). Results Percentile curves illustrated the developmental patterns of the SMMs of Korean children and adolescents. ASM and SMI increased with age in both genders, and increased from age 10 throughout adolescence in boys, whereas in girls, they increased until age 13 and then stabilized. In boys, %SMM and MFR were highest at age 15 and then slowly stabilized or decreased, whereas in girls, they peaked at age 10 to 11 and then decreased through adolescence. Cut-off values for low MFR were identified and a significant association was found between a low MFR and high risk of metabolic syndrome. However, this association was found to be dependent on gender and the level of BMI. Conclusion This study provides reference values of absolute and relative SMM for Korean children and adolescents. Detailed body composition analyses including skeletal muscle and fat mass might provide improved measures of metabolic risk.

Nutritional status of toddlers and preschoolers according to household income level: overweight tendency and micronutrient deficiencies.

BACKGROUNDS/OBJECTIVES The effects of malnutrition on growth of toddlers and preschoolers by socioeconomic status are not well known. This study aimed to examine the effects of dietary intake on growth outcomes in toddlers and preschoolers by household income level. SUBJECTS/METHODS The study population was a total of 1,687 children aged 1 to 5 years that participated in the KNHANES from 2009 to 2011. Growth of children was assessed by height for age (HFA) and weight for height (WFH). Children were classified into three groups according to childrens HFA and WFH compared to the 10th and 90th percentiles of the 2007 Korean Children and Adolescent Growth Standard. Average monthly household income was divided into quartile groups. Dietary intake data were obtained by using the one day 24-hr recall method. Risks of inadequate intake of nutrients and unfavorable growth were estimated by using a multiple logistic regression model adjusted for sex, age, region, and energy intake. RESULTS The low HFA group (< 10th percentile) had significantly lower intakes of energy, carbohydrate, and thiamin as compared with the high group (≥ 90th percentile). For WFH status, vitamin C intake was lower in the low group than in the high group. Household income level was related to WFH status but not HFA. Children from lower income households were more likely to have high WFH than those from higher income households (P for trend = 0.038). Household income status was also significantly related with risk of inadequate intake of micronutrients such as thiamin (P for trend = 0.032) and vitamin C (P for trend = 0.002), showing higher odds of inadequate intakes in children from lower income households. CONCLUSIONS Children from lower income households were prone to be overweight and to have inadequate intakes of micronutrients such as thiamin and vitamin C. To reduce nutritional and health disparities, collective action in the public sector is required from early life.

Dietary intake of fats and fatty acids in the Korean population: Korea National Health and Nutrition Examination Survey, 2013

BACKGROUND/OBJECTIVES The aim of this study was to estimate average total fat and fatty acid intakes as well as identify major food sources using data from the Korea National Health and Nutrition Examination Survey (KNHANES) VI-1 (2013). SUBJECTS/METHODS Total fat and fatty acid intakes were estimated using 24-hour dietary recall data on 7,048 participants aged ≥ 3 years from the KNHANES VI-1 (2013). Data included total fat, saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA), n-3 fatty acid (n-3 FA), and n-6 fatty acid (n-6 FA) levels. Population means and standard errors of the mean were weighted in order to produce national estimates and separated based on sex, age, income, as well as residential region. Major food sources of fat, SFA, MUFA, PUFA, n-3 FA, and n-6 FA were identified based on mean consumption amounts of fat and fatty acids in each food. RESULTS The mean intake of total fat was 48.0 g while mean intakes of SFA, MUFA, PUFA, n-3 FA, and n-6 FA were 14.4 g, 15.3 g, 11.6 g, 1.6 g, and 10.1 g, respectively. Intakes of MUFA and SFA were each higher than that of PUFA in all age groups. Pork was the major source of total fat, SFA, and MUFA, and soybean oil was the major source of PUFA. Milk and pork were major sources of SFA in subjects aged 3-11 years and ≥ 12 years, respectively. Perilla seed oil and soybean oil were main sources of n-3 FA in subjects aged ≥ 50 years and aged < 50 years, respectively. CONCLUSIONS Estimation of mean fatty acid intakes of this study using nationally represented samples of the Korean population could be useful for developing and evaluating national nutritional policies.

Factors contributing to participation in food assistance programs in the elderly population.

BACKGROUND/OBJECTIVES The study objectives were to examine the participation rate in food assistance programs and explore the factors that contribute to such participation among the Korean elderly population. SUBJECTS/METHODS The study sample comprised 3,932 respondents aged 65 years or older who were selected from a secondary data set, the fourth Korean Welfare Panel Study (KoWePS). The factors, related to participation in programs were examined based on the predisposing, enabling and need factors of the help-seeking behavior model. Multiple logistic regression analysis was used to select the best contributors among the factors related to program participation. RESULTS The predisposing rate in food assistance programs was 8.5% (7.1% for men and 10.4% for women). When all variables were included in the model, living without spouse, no formal education, low income, having social security benefits and food insecurity in elderly men, and age, low income, having social security benefits and feeling poor in elderly women were significantly related to a higher tendency to program participation. CONCLUSIONS The predisposing and need factors, such as living without spouse, low education level, food insecurity and feeling poor were important for program participation, as well as enabling factors, such as household income and social security benefits. A comprehensive approach considering these factors to identify the target population for food assistance programs is needed to increase the effectiveness and target population penetration of these programs.

Relationship between Socioeconomic Position and Suicide Attempts among the Korean Adolescents

This study explored the relationship of the subjective socioeconomic position (SEP) as well as the objective SEP with the rate of suicide attempts in 74,186 adolescents from the 2012 Korea Youth Risk Behavior Web-based Survey (KYRBS). The SEP was measured by the Family Affluence Scale (FAS) and the self-rated household economic status. The low perceived SEP for either the high or low FAS score was related to the elevated likelihood of suicide attempts in both genders. As compared with the adolescents in both the high level of perceived SEP and FAS score after adjusting for other confounding factors, the middle school students were more likely to attempt suicide in both low level of perceived SEP and FAS score (OR, 1.81; 95% CI, 1.18-2.78 for boys, OR, 1.46; 95% CI, 1.13-1.90 for girls). The high school students were more likely to attempt suicide in the low perceived SEP and high FAS score (OR, 1.44; 95% CI, 1.14-1.81 for boys, OR, 1.29; 95% CI, 1.07-1.56 for girls). In conclusion, the relationship of subjective SEP is important in suicide attempts as much as objective SEP and far more important in the high school students.