So Hun Kim

Improved Insulin Sensitivity and Adiponectin Level after Exercise Training in Obese Korean Youth

Objective: The objective of this study was to investigate the association among adiposity, insulin resistance, and inflammatory markers [high‐sensitivity C‐reactive protein (hs‐CRP), interleukin (IL)‐6, and tumor necrosis factor (TNF)‐α] and adiponectin and to study the effects of exercise training on adiposity, insulin resistance, and inflammatory markers among obese male Korean adolescents.

Association between polymorphisms in SLC30A8, HHEX, CDKN2A/B, IGF2BP2, FTO, WFS1, CDKAL1, KCNQ1 and type 2 diabetes in the Korean population

AbstractAccording to recent genome-wide association studies, a number of single nucleotide polymorphisms (SNPs) are reported to be associated with type 2 diabetes mellitus (T2DM). The aim of the present study was to investigate the association among the polymorphisms of SLC30A8, HHEX, CDKN2A/B, IGF2BP2, FTO, WFS1, CDKAL1 and KCNQ1 and the risk of T2DM in the Korean population. This study was based on a multicenter case-control study, including 908 patients with T2DM and 502 non-diabetic controls. We genotyped rs13266634, rs1111875, rs10811661, rs4402960, rs8050136, rs734312, rs7754840 and rs2237892 and measured the body weight, body mass index and fasting plasma glucose in all patients and controls. The strongest association was found in a variant of CDKAL1 [rs7754840, odds ratio (OR) = 1.77, 95% CI = 1.50–2.10, p = 5.0 × 10−11]. The G allele of rs1111875 (OR = 1.43, 95% CI = 1.18–1.72, p = 1.8 × 10−4) in HHEX), the T allele of rs10811661 (OR = 1.47, 95% CI = 1.23–1.75, p = 2.1 × 10−5) in CDKN2A/B) and the C allele of rs2237892 (OR = 1.31, 95% CI = 1.10–1.56, p = 0.003) in KCNQ1 showed significant associations with T2DM. Rs13266634 (OR = 1.19, 95% CI = 1.00–1.42, p = 0.045) in SLC30A8 showed a nominal association with the risk of T2DM, whereas SNPs in IGF2BP2, FTO and WFS1 were not associated. In conclusion, we have shown that SNPs in HHEX, CDKN2A/B, CDKAL1, KCNQ1 and SLC30A8 confer a risk of T2DM in the Korean population.

Effects of rosiglitazone and metformin on inflammatory markers and adipokines: decrease in interleukin‐18 is an independent factor for the improvement of homeostasis model assessment‐beta in type 2 diabetes mellitus

Objective  We examined the individual pharmacological effects of the addition of rosiglitazone and metformin to glimepiride on inflammatory markers and adipokines in patients with type 2 diabetes mellitus. We analysed the relationships between these variables, the measurements of insulin sensitivity and β‐cell function in patients treated with rosiglitazone plus glimepiride.

Effect of lifestyle modification on serum chemerin concentration and its association with insulin sensitivity in overweight and obese adults with type 2 diabetes

Chemerin, a recently identified adipokine, has been linked to adiposity, insulin resistance, metabolic syndrome risk factors and inflammation. Here, we evaluated whether a 12‐week lifestyle intervention in overweight and obese adults with type 2 diabetes could significantly affect the average blood glucose and serum chemerin levels over time.

Visceral fat amount is associated with carotid atherosclerosis even in type 2 diabetic men with a normal waist circumference.

Objective:Our objective was to investigate whether determination of the quantity of visceral fat has an additional benefit in assessing atherosclerotic burden in men with type 2 diabetes compared with the traditional measurement of waist circumference (WC) alone.Methods:This was an observational study performed in 368 men with type 2 diabetes, consecutively enrolled in Diabetes Clinics. Common carotid artery far-wall intima-media thickness (IMT), WC and visceral fat thickness (VFT), as measured by ultrasonography, were measured for each subject. Abdominal and visceral obesity were defined as a WC >90 cm and a VFT ⩾47.6 mm, respectively.Results:Among subjects with abdominal obesity (n=174), 35 subjects did not have visceral obesity. In contrast, among the subjects without abdominal obesity (n=194), 88 patients had visceral obesity. Despite no differences in age, glucose control, lipid profile and treatment modalities, there was a significant difference in carotid IMT based on VFT strata, but not WC strata. The subjects without abdominal obesity, but who had visceral obesity, had a higher carotid IMT compared with subjects with abdominal obesity, but without visceral obesity (maximal, 0.94±0.35 vs 0.78±0.17 mm; and average, 0.74±0.19 vs 0.64±0.14 mm, respectively, P<0.001).Conclusions:Subjects having visceral obesity, regardless of a normal WC, showed a higher carotid IMT compared with those with increased WC, but less visceral fat. In addition to WC, a direct estimation for visceral fat may provide an additional role in assessing atherosclerotic burden in men with type 2 diabetes.

Natural therapeutic magnesium lithospermate B potently protects the endothelium from hyperglycaemia-induced dysfunction

AIMS We have investigated the effects of magnesium lithospermate B (MLB), the active compound of the Oriental herbal remedy, Salvia miltiorrhizae, on endothelial dysfunction associated with diabetes mellitus using cultured endothelial cells and an animal model of type 2 diabetes mellitus. METHODS AND RESULTS The effect of MLB on vasodilatory function in Otsuka Long-Evans Tokushima Fatty (OLETF) rats was assessed. MLB treatment for 20 weeks starting at 12 weeks attenuated the decrease in endothelium-dependent vasodilation in OLETF rats. MLB treatment also increased serum nitrite level and reduced serum advanced glycation end products concentration. The effect of MLB was greater than an equivalent dose of alpha-lipoic acid (alphaLA), a popular antioxidant treatment. MLB rescued the inhibition of endothelial nitric oxide synthase (eNOS) activity and eNOS phosphorylation in endothelial cells cultured in hyperglycaemia. This effect was dependent on Akt phosphorylation and associated with decreased O-linked N-acetylglucosamine protein modification of eNOS. MLB also increased nuclear factor erythroid 2-related factor-2 (Nrf-2) activation in a phosphoinositide 3-kinase/Akt pathway dependent manner. MLB treatment induced the expression of the Nrf-2-regulated antioxidant enzyme, heme oxygenase-1. The antioxidant alphaLA could not produce this effect. Moreover, MLB decreased oxidative stress and endothelial cell apoptosis caused by hyperglycaemia. CONCLUSION MLB is a naturally occurring, new generation antioxidant that activates eNOS and ameliorates endothelial dysfunction in diabetes by enhancing vasodilation in addition to reducing oxidative stress. The relative strong performance of MLB makes it an ideal candidate for further, expanded trials as a new generation of antioxidant to treat diabetes-related complications.

Inhibition of adipogenesis in 3T3-L1 cells and suppression of abdominal fat accumulation in high-fat diet-feeding C57BL/6J mice after downregulation of hyaluronic acid.

Objective:Adipogenesis can be spatially and temporally regulated by extracellular matrix (ECM). We hypothesized that the regulation of hyaluronic acid (HA), a component of the ECM, can affect adipogenesis in fat cells. The effects of HA on adipogenesis were investigated in vitro in 3T3-L1 cells and in vivo in high-fat diet-feeding C57BL/6J mice.Methods:We investigated the effects of HA by degradation of pre-existing or synthesized HA and artificial inhibition of HA synthesis in adipogenesis.Results:In vitro adipogenesis in 3T3-L1 cells was inhibited by treating them with exogenous hyaluronidase (HYAL) and with 4-methylumbelliferone, which inhibited the synthesis of HA in a concentration-dependent manner. In vivo, abdominal fat accumulation in high-fat diet-feeding C57BL/6J mice was suppressed by exogenous HYAL 104 IU injections, which was associated with reduction of lipid accumulation in liver and increase of insulin sensitivity.Conclusion:Changes in the ECM such as accumulation of high molecular weight of HA by HAS and degradation of HA by endogenous HYAL were essential for adipogenesis both in vitro and in vivo.

Rubi Fructus (Rubus coreanus) activates the expression of thermogenic genes in vivo and in vitro

Objective:To investigate the anti-obesity effect of Rubi Fructus (RF) extract using brown adipose tissue (BAT) and primary brown preadipocytes in vivo and in vitro.Methods:Male C57BL/6 J mice (n=5 per group) were fed a high-fat diet (HFD) for 10 weeks with or without RF. Brown preadipocytes from the interscapular BAT of mice (age, post-natal days 1–3) were cultured with differentiation media (DM) including isobutylmethylxanthine, dexamethasone, T3, indomethacin and insulin with or without RF.Results:In HFD-induced obese C57BL/6 J mice, long-term RF treatment significantly reduced weight gain as well as the weights of the white adipose tissue, liver and spleen. Serum levels of total cholesterol and low-density lipoprotein cholesterol were also reduced in the HFD group which received RF treatment. Furthermore, RF induced thermogenic-, adipogenic- and mitochondria-related gene expressions in BAT. In primary brown adipocytes, RF effectively stimulated the expressions of thermogenic- and mitochondria-related genes. In addition, to examine whether LIPIN1, a regulator of adipocyte differentiation, is regulated by RF, Lipin1 small interfering RNA (siRNA) and RF were pretreated in primary brown adipocytes. Pretreatment with Lipin1 siRNA and RF downregulated the DM-induced expression levels of thermogenic- and mitochondria-related genes. Moreover, RF markedly upregulated AMP-activated protein kinase. Our study shows that RF is capable of stimulating the differentiation of brown adipocytes through the modulation of thermogenic genes.Conclusions:This study demonstrates that RF prevents the development of obesity in mice fed with a HFD and that it is also capable of stimulating the differentiation of brown adipocytes through the modulation of thermogenic genes, which suggests that RF has potential as a therapeutic application for the treatment or prevention of obesity.

Psychometric properties of a Korean version of the summary of diabetes self-care activities measure

BACKGROUND The summary of diabetes self-care activities (SDSCA) questionnaire is one of the most widely used self-report instruments for measuring diabetes self-management in adults. OBJECTIVES This study aimed to examine the psychometric properties of a Korean version of the SDSCA questionnaire. METHODS The 11-item English version of the SDSCA was translated into Korean following the standard translation methodology. The questionnaire was administered to 208 patients with type 2 diabetes. Exploratory and confirmatory factor analyses (EFA and CFA) were carried out for construct validity. Content validity index (CVI), internal consistency and a diabetes management self-efficacy scale (DMSES) were assessed. RESULTS The CVI of a Korean version of the SDSCA was .83. The EFA yielded a 9-item measure with a four factor solution with the same labels for original scales. The results of CFA showed the goodness of fit in the 9-item Korean SDSCA version (SDSCA-K). The internal consistency of SDSCA-K was moderate (Cronbachs α=.69) and the positive correlation between the SDSCA-K and the DMSES was identified. CONCLUSION The current study provides the initial psychometric properties of SDSCA-K modified to 9 items and supports SDSCA-K as a reliable and valid measure of diabetes self-management in Korean patients.

Development and Validation of a Semi-Quantitative Food Frequency Questionnaire to Assess Diets of Korean Type 2 Diabetic Patients

Background Our aim was to assess the validity of a semi-quantitative food frequency questionnaire (FFQ) by comparison with the 3-day diet record (DR) in patients with type 2 diabetes. Methods Eighty five type 2 diabetic patients (aged 33 to 70 years) from the Korean National Diabetes Program (KNDP) completed 3-day DR and FFQ. The FFQ was designed to reflect the eating pattern of Korean type 2 diabetic patients, and was based on the 2003 Korean National Health and Nutrition Examination Survey. The FFQ consists of 85 food items and 12 food groups. The validity of FFQ was assessed by comparison with the 3-day DR. Results The mean age was 49 ± 10 years. Clinical characteristic including body weight, diabetic duration, and HbA1c were not different from the total cohort subjects (n = 1,478). There were no significant differences in the mean intake of protein, fat and calcium estimated by the FFQ and the 3-day DR. Energy and carbohydrate estimated by the FFQ were higher than those estimated by the 3-day DR. The correlation coefficient was highest for energy (r = 0.740; P < 0.00) and lowest for iron (r = 0.269; P < 0.05). The Kappa values for energy, carbohydrate, protein, fat and calcium were 0.54, 0.37, 0.36, 0.46, and 0.19, respectively. Conclusion The FFQ is a reasonable instrument for assessing the intake of most macronutrients in Korean type 2 diabetes, although careful consideration is required for the food groups and nutrients for which the FFQ had low validity.