• Korean Journal of Psychosomatic Medicine
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• v.26 no.2
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• pp.86-93
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• 2018

Objectives : The purpose of this study was to investigate the association between the insulin resistance and depressive mood, suicidal ideation, psychological stress, and quality of life in general Korean population. Methods : We selected 3,613 subjects from the third year's data of 6th Korean National Health and Nutritional Examination Survey. Insulin resistance was evaluated with Homeostatic Model Assessment of Insulin Resistance. Questionnaires on depressive mood, suicidal ideation and psychological stress were conducted. The quality of life was assessed with the EuroQol-5 dimension index. We used correlation and regression analysis for analysis. Results : The risk of depressive mood and suicidal ideation was significantly higher in the insulin resistance group than in the control group. The risk of psychological stress was significantly higher in the male group with insulin resistance. The EuroQol-5 dimension index showed a negative correlation with insulin resistance. After adjusting for age, sex and body mass index, increased risk of suicidal ideation was identified only. Conclusions : We confirmed that insulin resistance is associated to mental health problems related with depression in Korean adults.

• Korean Journal of Biological Psychiatry
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• v.19 no.4
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• pp.187-192
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• 2012

Objectives Although antipsychotic drug clozapine has superior efficacy, this is hampered by metabolic side effects such as weight gain and diabetes. Recent studies demonstrate that clozapine induces insulin resistance. However, the identity and location of insulin resistance induced by clozapine has not been clarified. In this study, the effect of clozapine on central insulin response was investigated in rats. Methods Male Sprague-Dawley rats received intraperitoneal injection of clozapine or vehicle, which was followed by intracerebroventricular injection of insulin or its vehicle. The effects of clozapine on insulin-induced changes in blood glucose level and Akt phosphorylation in hypothalamus were investigated. Results Intraperitoneal injection of clozapine (20 mg/kg) increased blood glucose in rats. Intracerebroventricular injection of insulin reduced blood glucose in rats, which was blunted by pretreatment of clozapine. Accompanied with the antagonistic effect of clozapine to central insulin action in terms of blood glucose, clozapine inhibited the insulin-induced phosphorylation of Akt at Ser473 in rat hypothalamus. Conclusion Administration of clozapine inhibited the central insulin-induced changes in blood glucose and Akt phosphorylation in rat hypothalamus. These findings suggest that hypothalamus could be the site of action for the clozapine-induced insulin resistance.

• Journal of Microbiology and Biotechnology
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• v.25 no.5
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• pp.753-757
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• 2015

Recently, Lactobacillus rhamnosus GG (LGG) was shown to exert insulin-sensitizing and adiposity-reducing effects in high-fat (HF) diet-fed mice. In the present study, we observed that the effects were correlated with the extent of dysbiosis induced by HF diet feeding before LGG administration. LGG-treated mice were protected from HF diet-induced adiposity and/or insulin resistance when LGG was treated after, not along with, HF diet feeding. Results indicate that, under HF dietary condition, supplemented LGG reverses insulin resistance, but does not block its onset.

• Korean Journal of Biological Psychiatry
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• v.10 no.2
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• pp.107-115
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• 2003

Objective:The purpose of this study was to know about the mechanism of pathogenesis of type 2 diabetes mellitus by using of blood glucose, glucoregulatory factor, insulin resistance in schizophrenic patients receiving antipsychotics. Method:Modified oral glucose tolerance tests were performed in 20 schizophrenic patients receiving haloperidol, risperidone and olanzapine. Insulin, glucagon, C-peptide and cortisol were measured in 0, 15, 45, 75 minutes after glucose loading, and insulin resistance was calculated by HOMA(homeostasis model assessment) method. Result:Olanzapine-treated patients had significant glucose elevation 45 minutes after glucose challenge. Also modest increases in HOMA IR values were detected in patients treated with olanzapine. Conclusion:Olanzapine treatment of non-diabetic patients with schizophrenia can be associated with type 2 diabetes mellitus through the elevation of glucose and insulin resistance. Elevated insulin resistance may be a causative mechanism of type 2 diabetes mellitus in patients receiving olanzapine.

• Nutrition Research and Practice
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• v.4 no.4
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• pp.311-316
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• 2010

The purpose of this study was to investigate the relationship between birth weight and appetite related hormones, insulin resistance, and antioxidant status in overweight children aged 9-10 years. Thirty-four healthy overweight children (18 boys, 16 girls) were evaluated with respect to anthropometric measurement, lipid profiles, leptin, ghrelin, glucose, insulin, C-peptide, lipid soluble vitamins, and antioxidant enzyme activities. I found that birth weight was negatively correlated with insulin resistance parameters, ghrelin, and coenzyme Q10 levels. There was a significant positive correlation between present BMI and leptin level, while a negative correlation was noted between the BMI and $\alpha$-tocopherol and lycopene levels. When total subjects were classified into three groups by tertiles of birth weight, the lowest tertile of birth weight (LTB) group showed higher levels of fasting glucose, HOMA-IR, and ghrelin level than the highest tertile of birth weight (HTB) groups. On the other hand, HTB group showed an increased oxidative stress (decreased coenzyme Q10 level and catalase activity) compared to the LTB group. In conclusion, plasma ghrelin level might play an important role in accelerated growth in overweight children with LTB. Increased insulin resistance is present in overweight children with LTB, while decreased coenzyme Q10 and catalase activity in overweight children with HTB. These results suggest that birth weight might be an important factor for determination of treatment for obesity related complications in childhood obesity.

• The Journal of Internal Korean Medicine
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• v.37 no.4
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• pp.609-623
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• 2016

Objective: This study was undertaken to investigate the effects of Mori folium on insulin resistance and adipose tissue inflammation in an experimental mouse model of obesity.Methods: Obesity was induced in C57BL/6 mice by feeding them a high-fat diet. The mice were divided into four groups (n=6): a normal diet, high-fat diet, high-fat diet with 40 mg of Mori folium, and high-fat diet with 800 mg of Mori folium groups. After 13 wk, the body weights, fasting blood glucose and fasting serum insulin levels, insulin resistance (homeostatic model assessment) levels, oral glucose tolerance test levels, epididymal fat and liver weights, and gene expression of tumor necrosis factor-α, interleukin-6, and interferon-γ were measured. In addition, adipose tissue macrophages were analyzed by fluorescence-activated cell sorting.Results: Mori folium significantly reduced blood glucose levels, oral glucose tolerance levels, and liver weights. It also reduced adipose tissue macrophage numbers and tumor necrosis factor receptor-α gene expression.Conclusions: These results show that Mori folium has insulin resistance reduction and anti-inflammatory effects in an experimental mouse model of obesity.

• The Korean Journal of Food And Nutrition
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• v.30 no.4
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• pp.830-840
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• 2017

Excessive body weight gain during the growth period of early life may predispose individuals towards obesity and metabolic disorder in later life. We investigated the possibility of using the food efficiency ratio as an early indicator for predicting susceptibility to diet-induced obesity and insulin resistance. Four-week-old, prepubertal, male Sprague Dawley rats were divided into obesity-prone and obesity-resistant groups based on food efficiency ratio values after five days on a high-fat diet. Metabolic parameters measured after 2, 6, and 10 weeks, and specific phenotypes were compared with each group. Obesity-prone rats had higher increases in body weight and fat mass compared to obesity-resistant rats over the study period. Obesity-prone rats became glucose intolerant early in this study and remained so throughout the experimental period, with increases in fat weight and leptin levels occurring first, followed by increases in insulin level. Gluconeogenesis and insulin resistance significantly increased in obesity-prone groups in which activities of glucose-6-phosphatase and phosphoenolpyruvate carboxykinase were increased and glucokinase activity decreased. Higher food efficiency ratio at an early age was closely correlated with body fat accumulation, hyperleptinemia, and hyperinsulinemia of middle and elderly age. We suggest a high food efficiency ratio in prepubertal subjects may be a useful predictor of future obesity and insulin resistance.

• Journal of Pharmacopuncture
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• v.20 no.4
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• pp.235-242
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• 2017

Irisin is a novel hormone like polypeptide that is cleaved and secreted by an unknown protease from fibronectin type III domain-containing protein 5 (FNDC5), a membrane-spanning protein and which is highly expressed in skeletal muscle, heart, adipose tissue, and liver. Since its discovery in 2012, it has been the subject of many researches due to its potent physiological role. It is believed that understanding irisin's function may be the key to comprehend many diseases and their development. Irisin is a myokine that leads to increased energy expenditure by stimulating the 'browning' of white adipose tissue. In the first description of this hormone, increased levels of circulating irisin, which is cleaved from its precursor fibronectin type III domain-containing protein 5, were associated with improved glucose homeostasis by reducing insulin resistance. Irisin is a powerful messenger, sending the signal to determine the function of specific cells, like skeletal muscle, liver, pancreas, heart, fat and the brain. The action of irisin on different targeted tissues or organs in human being has revealed its physiological functions for promoting health or executing the regulation of variety of metabolic diseases. Numerous studies focus on the association of irisin with metabolic diseases which has gained great interest as a potential new target to combat type 2 diabetes mellitus and insulin resistance. Irisin is found to improve insulin resistance and type 2 diabetes by increasing sensitization of the insulin receptor in skeletal muscle and heart by improving hepatic glucose and lipid metabolism, promoting pancreatic ${\beta}$ cell functions, and transforming white adipose tissue to brown adipose tissue. This review is a thoughtful attempt to summarize the current knowledge of irisin and its effective role in mediating metabolic dysfunctions in insulin resistance and type 2 diabetes mellitus.

• Journal of Nutrition and Health
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• v.34 no.5
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• pp.485-492
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• 2001

The prevalence of type 2 diabetes mellitus has been rapidly increased in parallel with the westernization of eating behavior in Korea. Increased consumption of animal fat and simple sugar can be potential contributors for insulin resistance. The purpose of the study was to determine whether Western-(WD) and Korean-style(KD) diets altered insulin secretion and insulin resistance in male Sprague Dawley rats. Rats weighing 98$\pm$5g were provided by KD(77 En% of starch, 5 En% of corn oil and 13 En% of gluten plus 5 En% of casein), WD(42 En% of starch, 40 En% of butter and 18% of casein) or control diet(62 En% of starch, 20 En% of corn oil and 18% of casein) for 12 weeks. Body weights were lower in KD compared to WD. Fasting blood glucose levels were not different among diets. Insulin secretion from the beta cells was higher by 2.2$\pm$0.4 folds in WD than KD at baseline. In hyperglycemic clamp insulin secretion was higher in WD than KD and CD. Whole body glucose disposal rates referred to the state of insulin sensitivity were lowest in WD among groups. Glycogen deposits in soleus and quadriceps muscles were lowest in WD among all groups, but their triglyceride contents were highest. GLUT4 contents and glycogen synthase were lowest in WD in both muscles. In conclusions, westernization of diets needed more insulin to normalization of blood glucose levels due to increased insulin resistance. Thus, WD would lead to increased prevalence of diabetes mellitus when increased insulin resistance could not be compensated by insulin secretion in the case of elevated blood glucose levels. (Korean J Nutriton 34(5) : 485~492, 2001)

• Journal of Nutrition and Health
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• v.40 no.1
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• pp.31-40
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• 2007

The purpose of this study was to investigate the association between insulin resistance and cardiovascular disease risk factors in Korean type 2 diabetes patients. The subjects were 429 (male: 218, female: 211) type 2 DM patients visited DM clinic, and they were classified into quartiles based on $K_{ITT}$ index (%/min, Insulin Tolerance Test). Anthropometric and biochemical characteristics, and dietary intakes by Food Frequency Questionnaire were assessed. The means of waist circumference, fat mass, percent body fat and abdominal fat thickness were significantly higher in the lowest quartile (the most insulin resistant group) than in the highest quartile (the least insulin resistant group) of $K_{ITT}$ index (%/min)(p<0.05), For hematological values, the lowest quartile showed significantly higher fasting blood glucose, HbA1c, C-peptide, insulin, triglyceride, ApoB/apoA-1 ratio and C-reactive protein compared to the highest quartile (p < 0.05). Moreover, $K_{ITT}$ index (%/min) was negatively correlated with waist circumference, fat mass, percent body fat, abdominal fat thickness and fasting blood concentrations of glucose, HbA1c, C-peptide, insulin, cholesterol, triglyceride, ApoB/apoA-1 ratio and C-reactive protein (p < 0.05). Nutrient intakes were not significantly different among the quartile groups of $K_{ITT}$ index (%/min) and also not correlated with insulin resistance, however, they showed correlation with obesity parameters (BMI, waist circumference, waist-hip ratio, vat mass, abdominal fat thickness), which were strongly associated with insulin resistance. In conclusion, cardiovascular disease risk would be higher as the insulin resistance grows in Korean type 2 DM patients, and nutrient intakes would affect to the insulin resistance through the effect on anthropometric parameters.