Expanded IL-22+ Group 3 Innate Lymphoid Cells and Role of Oxidized LDL-C in the Pathogenesis of Axial Spondyloarthritis with Dyslipidaemia

Group 3 innate lymphoid cells (ILC3), which express IL-22 and IL-17A, has been introduced as one of pathologic cells in axial spondyloarthritis (axSpA). Dyslipidaemia should be managed in axSpA patients to reduce cardiovascular disease, and dyslipidaemia promotes inflammation. This study aimed to reveal the role of circulating ILC3 in axSpA and the impact of dyslipidaemia on axSpA pathogenesis. AxSpA patients with or without dyslipidaemia and healthy control were recruited. Peripheral blood samples were collected, and flow cytometry analysis of circulating ILC3 and CD4+ T cells was performed. The correlation between Ankylosing Spondylitis Disease Activity Score (ASDAS)-C-reactive protein (CRP) and circulating immune cells was evaluated. The effect of oxidized low-density lipoprotein cholesterol (oxLDL-C) on immune cell differentiation was confirmed. AxSpA human monocytes were cultured with with oxLDL-C, IL-22, or oxLDL-C plus IL-22 to evaluate osteoclastogenesis using tartrate-resistant acid phosphatase (TRAP) staining and realtime quantitative PCR of osteoclast-related gene expression. Total of 34 axSpA patients (13 with dyslipidaemia and 21 without) were included in the analysis. Circulating IL-22+ ILC3 and Th17 were significantly elevated in axSpA patients with dyslipidaemia (p=0.001 and p=0.034, respectively), and circulating IL-22+ ILC3 significantly correlated with ASDAS-CRP (Rho=0.4198 and p=0.0367). Stimulation with oxLDL-C significantly increased IL-22+ ILC3, NKp44 − ILC3, and Th17 cells, and these were reversed by CD36 blocking agent. IL-22 and oxLDL-C increased TRAP + cells and osteoclast-related gene expression. This study suggested potential role of circulating IL-22+ ILC3 as biomarker in axSpA. Furthermore, dyslipidaemia augmented IL-22+ ILC3 differentiation, and oxLDL-C and IL-22 markedly increased osteoclastogenesis of axSpA.

How Well Can Matrix of Ferritin and Neutrophil to Lymphocyte Ratio Predict Metabolic Syndromein Korean Adults?

Background@#Previous studies have shown that elevated ferritin level and neutrophil to lymphocyte ratio (NLR) are risk factors of chronic low-gradeinflammation and contribute to the onset and progression of cardiovascular disease. In addition, metabolic syndrome has a similar relevance; thus,in this study, we aimed to determine how well metabolic syndrome could be predicted by measuring ferritin level and NLR. @*Methods@#From January 2016 to September 2018, 1,815 adults who underwent medical interviews, physical measurements, and blood tests at amedical examination center of a university hospital in Seoul were evaluated. Data were analyzed using the Spearman correlation analysis, anaverage comparison using analysis of variance, and a t test. The prevalence of metabolic syndrome was determined according to ferritin level andNLR. @*Results@#We found a significant correlation between the components of metabolic syndrome and ferritin level, but not NLR. The NLRs were divided intoquartiles for comparison with the mean values of the components of metabolic syndrome, but the results were not significant. A significantdifference was found only in ferritin level when we compared the mean values of ferritin level and NLR according to the presence or absence of ametabolic syndrome diagnosis. When ferritin level and NLR were considered simultaneously, the prevalence of metabolic syndrome tended tochange only when the ferritin level changed. @*Conclusion@#In healthy Korean adults, ferritin level, but not NLR, could be used as a predictor of metabolic syndrome.

Application of Relative Fat Mass Equation in Korean Adults

Background@#Body mass index (BMI) has limitations in determining body fat percentage and body fat distribution, and causes misclassification of body fat-defined obesity. As high body fat percentage is associated with mortality, an accurate assessment of body fat percentage is considered clinically important. Recently, Woolcott and Bergman reported a relative fat mass (RFM) equation which calculated the body fat percentage using the height and waist circumferences. However, as RFM has been studied only in European-, Mexican-, and African-Americans, an assessment in Asians was needed. Therefore, we aimed to evaluate the applicability of RFM in Korean adults. @*Methods@#This study included 7,733 adults who visited a Sanggye Paik Hospital Health Promotion Center from May 1, 2016 to November 12, 2018. BMI and RFM were calculated by measuring height, weight, and waist circumference. The total body fat (TBF) percentage was measured by bioelectrical impedance analysis. We compared the BMI, RFM, and TBF percentage to assess the applicability of RFM in Korean adults. @*Results@#RFM had a statistically significant correlation with TBF percentage in both male and female (male: β=0.808, R2=0.653, female: β=0.766, R2=0.587, P<0.001). In the Bland-Altman plot, RFM showed good agreement with the TBF percentage within the 95% confidence interval. @*Conclusion@#The RFM equation can be used to predict TBF percentage in Korean adults.

GRIM-19 Ameliorates Multiple Sclerosis in a Mouse Model of Experimental Autoimmune Encephalomyelitis with Reciprocal Regulation of IFNγ/Th1 and IL-17A/Th17 Cells

The protein encoded by the Gene Associated with Retinoid-Interferon-Induced Mortality-19 (GRIM-19) is located in the mitochondrial inner membrane and is homologous to the NADH dehydrogenase 1-alpha subcomplex subunit 13 of the electron transport chain.Multiple sclerosis (MS) is a demyelinating disease that damages the brain and spinal cord.Although both the cause and mechanism of MS progression remain unclear, it is accepted that an immune disorder is involved. We explored whether GRIM-19 ameliorated MS by increasing the levels of inflammatory cytokines and immune cells; we used a mouse model of experimental autoimmune encephalomyelitis (EAE) to this end. Six-to-eight-week-old male C57BL/6, IFNγ-knockout (KO), and GRIM-19 transgenic mice were used; EAE was induced in all strains. A GRIM-19 overexpression vector (GRIM19 OVN) was electrophoretically injected intravenously. The levels of Th1 and Th17 cells were measured via flow cytometry, immunofluorescence, and immunohistochemical analysis. IL-17A and IFNγ expression levels were assessed via ELISA and quantitative PCR. IL-17A expression decreased and IFNγ expression increased in EAE mice that received injections of the GRIM19 OVN. GRIM-19 transgenic mice expressed more IFNγ than did wild-type mice; this inhibited EAE development. However, the effect of GRIM-19 overexpression on the EAE of IFNγ-KO mice did not differ from that of the empty vector. GRIM-19 expression was therapeutic for EAE mice, elevating the IFNγ level. GRIM-19 regulated the Th17/Treg cell balance.

GRIM-19 Ameliorates Multiple Sclerosis in a Mouse Model of Experimental Autoimmune Encephalomyelitis with Reciprocal Regulation of IFNγ/Th1 and IL-17A/Th17 Cells

The protein encoded by the Gene Associated with Retinoid-Interferon-Induced Mortality-19 (GRIM-19) is located in the mitochondrial inner membrane and is homologous to the NADH dehydrogenase 1-alpha subcomplex subunit 13 of the electron transport chain.Multiple sclerosis (MS) is a demyelinating disease that damages the brain and spinal cord.Although both the cause and mechanism of MS progression remain unclear, it is accepted that an immune disorder is involved. We explored whether GRIM-19 ameliorated MS by increasing the levels of inflammatory cytokines and immune cells; we used a mouse model of experimental autoimmune encephalomyelitis (EAE) to this end. Six-to-eight-week-old male C57BL/6, IFNγ-knockout (KO), and GRIM-19 transgenic mice were used; EAE was induced in all strains. A GRIM-19 overexpression vector (GRIM19 OVN) was electrophoretically injected intravenously. The levels of Th1 and Th17 cells were measured via flow cytometry, immunofluorescence, and immunohistochemical analysis. IL-17A and IFNγ expression levels were assessed via ELISA and quantitative PCR. IL-17A expression decreased and IFNγ expression increased in EAE mice that received injections of the GRIM19 OVN. GRIM-19 transgenic mice expressed more IFNγ than did wild-type mice; this inhibited EAE development. However, the effect of GRIM-19 overexpression on the EAE of IFNγ-KO mice did not differ from that of the empty vector. GRIM-19 expression was therapeutic for EAE mice, elevating the IFNγ level. GRIM-19 regulated the Th17/Treg cell balance.

The Relationship between Serum Uric Acid and Ankle Brachial Index in Korean Men

BACKGROUND: Elevated serum uric acid (UA) level is a known risk factor for atherosclerotic diseases, including peripheral arterial disease (PAD). PAD is easily diagnosed by determining the ankle-brachial index (ABI). The relationship between serum UA and subclinical atherosclerotic diseases remains controversial. We therefore aimed to explore an independent association between UA and ABI in healthy Korean men.METHODS: A cross-sectional study was conducted in 664 male participants aged ≥19 years who visited our Center for Health Promotion. The ABI and serum UA were determined for all participants and the relationship between these parameters and between ABI and other variables was assessed with the Pearson correlation coefficient. Multiple regression analysis was conducted to determine an independent correlation between serum UA and ABI after adjustment for certain variables. Analysis of covariance was employed to identify a trend in the ABI relative to UA quartiles.RESULTS: The ABI correlated inversely with UA and variables such as body mass index, diastolic blood pressure, heart rate, total cholesterol, triglycerides, and low-density lipoprotein-cholesterol. UA showed an independent inverse correlation with the ABI after serial adjustment for these variables (β=−0.265, P < 0.001). A decreasing trend in the ABI was observed with increasing UA quartile (P < 0.001).CONCLUSION: UA shows an independent inverse correlation with ABI in healthy Korean men.

Correlation between Serum Uric Acid and Bone Mineral Content in Healthy Women

BACKGROUND: Osteoporosis is a systemic skeletal disease characterized by reduced bone mineral density and skeletal microstructural abnormalities. We investigated the correlation between serum uric acid (SUA) levels and bone mineral content (BMC) values as a surrogate marker of bone health. Additionally, we assessed whether the correlation, if any, was evident even after classifying the study population into two groups based on a diagnosis of obesity in these individuals.METHODS: This study included 936 women who visited the healthcare centers that participated in this study. Fasting blood samples were obtained from all women to measure SUA, BMC of the lumbar spine was measured using dual-energy X-ray absorptiometry. We evaluated the correlation between SUA and BMC in obese and non-obese groups.RESULTS: SUA concentration and BMC were positively correlated (β=0.257, P=0.001); however, this correlation was significant only in the obese group (β=0.203, P=0.001).CONCLUSION: SUA concentration and BMC are positively correlated in women diagnosed obesity.

Correlation between Serum Uric Acid and Carotid Intima-Media Thickness in Korean Women

BACKGROUND: Serum uric acid (UA) has been found to be associated with hypertension, obesity, dyslipidemia, and metabolic syndrome; however, its role as an independent risk factor of cardiovascular disease (CVD) is still controversial. There have been very few studies reporting an association between UA levels and carotid intima-media thickness (CIMT), especially in women.METHODS: The study included 245 subjects whose CIMT was evaluated between February 2016 and December 2017 at a health promotion center. We divided the population into two groups on the basis of menopausal status: premenopausal women (n=78) and postmenopausal women (n=167). We measured blood pressure, serum lipid profile, fasting blood glucose (FBG), and creatinine and UA levels. CIMT was measured using high-resolution B-mode ultrasonography.RESULTS: UA levels and CIMT were higher in postmenopausal women (P=0.029, P < 0.001). In premenopausal women, age (r=0.438), body mass index (r=0.373), UA (r=0.205), and FBG (r=0.336) were associated with CIMT, whereas in postmenopausal women, age (r=0.326), body mass index (r=0.167), UA (r=0.166), systolic blood pressure (r=0.200), and HDL-cholesterol (r=−0.140) were associated with CIMT. The UA level was independently associated with CIMT in premenopausal women (β=0.208, P=0.031), whereas age was the only factor independently associated with CIMT in postmenopausal women (β=0.253, P=0.002). Women in the highest tertile of uric acid level exhibited a higher CIMT than did those in the lowest tertile after age adjustment (P for trend < 0.001).CONCLUSION: UA may be an independent risk factor for CIMT, suggesting that UA is a risk factor for the early detection of CVD, especially in premenopausal women.

Martin's Equation as the Most Suitable Method for Estimation of Low-Density Lipoprotein Cholesterol Levels in Korean Adults / 가정의학회지

BACKGROUND: Friedewald equation is the most widely used method for estimating low-density lipoprotein cholesterol (LDL-C) level. However, due to potential over- or underestimation, many studies have used a modified equation. This study aimed to compare estimates by 4 different equations to directly measured LDL-C concentrations in order to propose the most appropriate method for LDL-C estimation in the Korean population. METHODS: We studied data of 4,350 subjects that included total cholesterol, high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), and LDL-C concentrations that had been measured at one university hospital in Seoul. We investigated 4 equations: LDL-C by Friedewald's original equation (LDL-C(F)) and its 3 modifications. Pearson correlation analysis was performed to compare these estimates to the direct measurement. RESULTS: Pearson correlation analysis revealed a good correlation among all 4 estimated LDL-C values and the directly measured LDL-C value. The Pearson coefficients were 0.951 for LDL-C(F), 0.917 for LDL-C by Hatta equation (LDL-C(H)), 0.968 for LDL-C by Puavilai equation (LDL-C(P)), and 0.983 for LDL-C by Martin equation (LDL-C(M)). Martin equation (LDL-C(M)) resulted in the best approximation (mean difference from the direct measurement, 5.5 mg/dL; mean percentage difference from the direct measurement, 5.1%) and the best agreement with the direct measurement (86.1%). LDL-C(P) resulted in the second-best approximation (mean difference, 7.0 mg/dL; mean percentage difference, 6.2%; concordance, 82.5%). LDL-C(M) was found to be less influenced by TG and HDL-C levels than by LDL-C(F). CONCLUSION: Estimates by Martin equation had the best agreement with direct LDL-C concentrations and both Martin and Puavilai equations were superior to Friedewald equation for estimating LDL-C concentrations in Korean adults.

Association between Vitamin D Concentration and Visceral Fat Area in Healthy Korean Adults

BACKGROUND: Studies on the relationship between vitamin D and visceral fat area (VFA; intra-abdominal fat area) have been actively conducted. But, there is a few Korean population-based studies about the association between serum vitamin D level and VFA. The aim of our study was to explore the correlation between serum 25-hydroxyvitamin D (25[OH]D) levels and VFA measured using bioelectrical impedance analysis (BIA; electric impedance) in healthy Korean adults. METHODS: This cross-sectional study involved 1,945 adults aged 20-70 years who visited a health promotion center. All subjects underwent the BIA to estimate the VFA. Serum 25(OH)D level was measured using chemiluminescent immunoassay. Multiple regression analysis was performed to identify independent correlation of VFA and serum 25(OH)D level. RESULTS: The prevalence of vitamin D deficiency (25[OH]D: 20-29 ng/mL) and insufficiency (25[OH]D <20 ng/mL) were 54.4% and 38.1%, respectively. After having adjusted age and season, VFA were negatively associated with serum 25(OH)D levels in both men (P<0.001) and women (P<0.001). The obese group with VFA ≥ 100 cm² had significant lower serum 25(OH)D level in men (P<0.001) and women (P=0.0034). CONCLUSIONS: VFA measured using BIA could be negatively associated with serum 25(OH)D levels in healthy Korean adult.

Letter: Association of Physical Activity and Body Fatness with Vitamin D Deficiency in Older Adults (Korean J Obes 2016;25:24-30)

No abstract available.

Current Methods of Human Body Composition Assessment

The present study reviews recently developed and commonly used methods for determination of body composition in vivo with relevance for nutritional assessment. Body composition measurement methods are continuously being improved, with the most commonly used methods being bioelectrical impedance analysis, dual energy X-ray absorptiometry, computed tomography, and magnetic resonance imaging or magnetic resonance spectroscopy. Recent developments include three-dimensional photonic scanning, quantitative magnetic resonance, and air displacement plethysmography. Collectively, these techniques allow for the measurement of fat, fat-free mass, bone mineral content, total body water, extracellular water, total adipose tissue and its subdepots (visceral, subcutaneous, and intermuscular), skeletal muscle, select organs, and ectopic fat depots.

2014 Clinical Practice Guidelines for Overweight and Obesity in Korea

The dramatic increase in the prevalence of obesity and its accompanying comorbidities are major health concerns in Korea. Obesity is defined as a body mass index > or =25 kg/m2 in Korea. Current estimates are that 32.8% of adults are obese: 36.1% of men and 29.7% of women. The prevalence of being overweight and obese in national surveys is increasing steadily. Early detection and the proper management of obesity are urgently needed. Weight loss of 5% to 10% is the standard goal. In obese patients, control of cardiovascular risk factors deserves the same emphasis as weight-loss therapy. Since obesity is multifactorial, proper care of obesity requires a coordinated multidisciplinary treatment team, as a single intervention is unlikely to modify the incidence or natural history of obesity.

Neuromuscular Electrical Stimulation Therapy for Dysphagia Caused by Wilson's Disease

Wilson's disease is an autosomal recessive disorder of abnormal copper metabolism. Although dysphagia is a common complaint of patients with Wilson's disease and pneumonia is an important cause of death in these patients, management of swallowing function has rarely been reported in the context of Wilson's disease. Hence, we report a case of Wilson's disease presenting with dysphagia. A 33-year-old man visited our hospital with a complaint of difficulty in swallowing, since about last 7 years and which had worsened since the last 2-3 months. He was diagnosed with Wilson's disease about 13 years ago. On the initial VFSS, reduced hyoid bone movement, impaired epiglottic movement and moderate amount of residue in the valleculae during the pharyngeal phase were noted. After 10 sessions of neuromuscular electrical stimulation for 1 hour per day, decreased amount of residue was observed in the valleculae during the pharyngeal phase on the follow-up VFSS.

Neuromuscular Electrical Stimulation Therapy for Dysphagia Caused by Wilson's Disease

Wilson's disease is an autosomal recessive disorder of abnormal copper metabolism. Although dysphagia is a common complaint of patients with Wilson's disease and pneumonia is an important cause of death in these patients, management of swallowing function has rarely been reported in the context of Wilson's disease. Hence, we report a case of Wilson's disease presenting with dysphagia. A 33-year-old man visited our hospital with a complaint of difficulty in swallowing, since about last 7 years and which had worsened since the last 2-3 months. He was diagnosed with Wilson's disease about 13 years ago. On the initial VFSS, reduced hyoid bone movement, impaired epiglottic movement and moderate amount of residue in the valleculae during the pharyngeal phase were noted. After 10 sessions of neuromuscular electrical stimulation for 1 hour per day, decreased amount of residue was observed in the valleculae during the pharyngeal phase on the follow-up VFSS.

A Survey on Activities of Daily Living and Occupations of Upper Extremity Amputees

OBJECTIVE: To assess prosthetic use by upper extremity amputees, and their difficulties with prostheses in activities of daily living and occupations. METHOD: This study is based on a survey of 307 subjects, who were using prostheses manufactured in the Center of Prosthetics and Orthotics. The survey questionnaire included items about general demographic characteristics, side and level of amputation, type of prosthesis and its use, and difficulties in the activities of daily living, employment and driving. RESULTS: The most common type of prosthesis was the cosmetic hand type (80.2%). There were no statistically significant correlations between satisfaction with prosthesis and the amputation level or type of prosthesis. The most common difficulties in daily living activities experienced by amputees were lacing shoes, removing bottle-tops with a bottle opener, and using scissors. Only 7.3% of amputees received rehabilitation services. Less than half of the amputees (44.7%) used their prostheses for eight or more hours a day, and 76.9% used their prostheses for regular or irregular cosmetic purposes. After amputation, most of the respondents (69.0%) became unemployed or changed workplaces. CONCLUSION: In our study, respondents preferred cosmetic usage to functional usage. Only 30.0% of respondents reported satisfaction with their prostheses. Many of the amputees had difficulties in complex tasks and either changed jobs or became unemployed. Clerical workers were the occupation group, which was most likely to return to work. The development of a more functional prosthetic hand and additional rehabilitation services are required.

Engagement of Toll-Like Receptor 3 Induces Vascular Endothelial Growth Factor and Interleukin-8 in Human Rheumatoid Synovial Fibroblasts

BACKGROUND/AIMS: Angiogenesis, which is a critical step in the initiation and progression of rheumatoid arthritis (RA), involves pro-angiogenic factors, including interleukin (IL)-8 and vascular endothelial growth factor (VEGF). We investigated the role of Toll-like receptor 3 (TLR3) in the regulation of pro-angiogenic factors in RA fibroblast-like synoviocytes (FLS). METHODS: FLS were isolated from RA synovial tissues and stimulated with the TLR3 ligand, poly (I:C). The levels of VEGF and IL-8 in the culture supernatants were measured using enzyme-linked immunosorbent assays, and the mRNA levels were assessed by semiquantitative reverse transcription-polymerase chain reaction. The expression patterns of VEGF and IL-8 in the RA synovium and osteoarthritis (OA) synovium were compared using immunohistochemistry. RESULTS: The expression levels of TLR3, VEGF, and IL-8 were significantly higher in the RA synovium than in the OA synovium. VEGF and IL-8 production were increased in the culture supernatants of RA FLS stimulated with poly (I:C), and the genes for these proteins were up-regulated at the transcriptional level after poly (I:C) treatment. Treatment with inhibitors of nuclear factor-kappaB (NF-kappaB), i.e., pyrrolidine dithiocarbamate and parthenolide, abrogated the stimulatory effect of poly (I:C) on the production of VEGF and IL-8 in RA FLS. CONCLUSIONS: Our results suggest that the activation of TLR3 in RA FLS promotes the production of proangiogenic factors, in a process that is mediated by the NF-kappaB signaling pathway. Therefore, targeting the TLR3 pathway may be a promising approach to preventing pathologic angiogenesis in RA.

IL-10 Inihibits VEGF Production in the Synovial Fibroblasts of RA Patients via Down-regulation of the ERK and AP-1 Pathways / 대한류마티스학회지

OBJECTIVE: Interleukin (IL)-10 has been demonstrated to have anti-inflammatory and anti-tumour activity. Because aberrant angiogenesis is a significant pathogenic component of tumor growth and chronic inflammation, we investigated the effect of IL-10 on the production of vascular endothelial growth factor (VEGF) by the synovial fibroblasts derived from the patients with rheumatoid arthritis (RA). METHODS: Fibroblast-like synoviocytes (FLS) were cultured with transforming growth factor (TGF-beta) alone or with IL-10. The level of VEGF was measured by RT-PCR and enzyme-linked immunosorbent assay (using the 24, 48 and 72 h culture supernatants). The FLSs were cultured with TGF-b for 48 hr in the presence of PD98059 (an ERK inhibitor), curcumin and SP600125 (a JNK and Ap-1 inhibitor, respectively). The level of VEGF in the supernatants was measured by ELISA. Cell viability was assessed using MTT assay. The expressions of VEGF, ERK, AP-1 and IL-10 in the synovial tissue were quantified by immunohistochemistry. RESULTS: IL-10 exhibited the inhibitory effect on VEGF production when the FLSs were stimulated with TGF-beta. ERK and AP-1 inhibitors inhibited the TGF-beta induced VEGF production. Moreover, TGF-beta increased the phosphorylation of ERK and C-Jun, which was significantly inhibited by the IL-10. CONCLUSION: IL-10 may exert an antiangiogenic effect by inhibiting the ERK- and AP-1 mediated VEGF expression in rheumatoid synovial fibroblasts.

Urine Cotinine and Environmental Tobacco Exposure in Korean Adolescents / 가정의학회지

BACKGROUND: The aim of this study was to elucidate the relationship of environmental tobacco smoke (ETS) exposure and the urine cotinine concentrations in Korean adolescents. METHODS: The study population was 1st grade high school adolescents (n = 1467, girls 22.2%) recruited from four high schools, two from Seoul, one from Kangleung and one from Woolsan. We obtained information on active smoking and ETS exposure through self-reported questionnaire and urine cotinine concentrations. RESULTS: The prevalence of active smoking was 6.9% in boys and 0.9% in girls. Median urine cotinine concentrations were 19.5 microgram/L (range, 0-2341 microgram/L) among smokers, and 0 microgram/L (range, 0-1359 microgram/L) among nonsmokers. The positive rate of urine cotinine among nonsmokers exposed to ETS was 2.9%. Boys were exposed to ETS in the order of frequency in PC room (79.6%), home (39.4%), school (11.5%), and public places (5.9%); girls were exposed in the order of frequency in home (40.9%), PC room (33.2%), public places (28.0%), and school (15.2%). The frequency and duration of ETS exposure were significantly larger and longer in boys than in girls. Boys contacted friends who smoked more than girls did (32.6% vs. 17.1%). Parents; smoking status was similar both in boys and girls. Any information on ETS exposure did not differ according to the detectable urine cotinine among nonsmoking adolescents. CONCLUSION: Low positive rate of urine cotinine and no association of urine cotinine with various ETS exposure history reflect that urine cotinine may not be a good marker for ETS exposure in Korean adolescents.

Cutoff of Percent Body Fat to Predict Obesity and Metabolic Risk in Children and Adolescents: 2007 Children and Adolescent Physical Growth Standard / 가정의학회지

BACKGROUND: Body mass index (BMI) for gender and age and percentage-weight-for-height (PWH) for gender and height have been frequently used to diagnose childhood obesity. However, few studies have examined the optimal cutoff of percent body fat (%BF) to predict metabolic abnormalities in obese children. METHODS: One thousand fifteen obese children aged 10 to 15 years were enrolled in this study. The %BF cutoff values were calculated by ROC analysis for metabolic abnormalities. We also calculated %BF cutoff values corresponding to a BMI of > 85th or 95th percentile for gender and age and a PWH of > 120% for gender and height based on the 2007 Korean children and adolescents growth standard chart. To define metabolic abnormalities in children, we used the criteria of metabolic syndrome recommended by International Diabetes Federation consensus for children and adolescents. RESULTS: The %BF cutoff corresponding to the group having more than one metabolic abnormality in this study population were 38.4% (sensitivity 40.1%, specificity 84.4%) in total, 38.4% (sensitivity 35.4%, specificity 84.8%) in boys and 39.5% (sensitivity 38.9%, specificity 90.9%) in girls. The %BF cutoff values corresponding to a BMI > or = 95 percentile were 38.1% (sensitivity 50.5%, specificity 72.7%), a BMI > or = 85 percentile were 34.5% (sensitivity 69.3%, specificity 74.2%), and a PWH > or = 120% were 36.4% (sensitivity 72.3%, specificity 64.4%) in total. CONCLUSION: The optimal cutoff value of percent body fat to predict metabolic abnormalities in obese children may be 38.4% (boys 38.4, girls 39.5%) and we suggest 34.5% as a cutoff value of %BF for screening childhood obesity.