Bong Soo Cha

Yonsei University Hospital, Sŏul, Seoul, South Korea

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Publications (196)545.23 Total impact

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    ABSTRACT: We aimed to compare the efficacy and safety of lobeglitazone and pioglitazone as add-ons to metformin in patients with type 2 diabetes. Patients who were inadequately controlled by metformin were randomized and treated once daily with either lobeglitazone (0.5 mg, n = 128) or pioglitazone (15 mg, n=125) for 24 weeks, with a 28-week extension of lobeglitazone treatment in patients who consented. The primary endpoint was the change in HbA1c level between baseline and week 24. At week 24, the mean change from baseline HbA1c was −0.74% for the lobeglitazone group and −0.74% for the pioglitazone group, with a mean difference of 0.01% [95% confidence interval (CI) of difference, −0.16 to 0.18]. The effects of lobeglitazone on lipid parameters and adverse events associated with lobeglitazone were similar to those achieved with pioglitazone. Lobeglitazone was not inferior to pioglitazone as an add-on to metformin in terms of the efficacy and safety.
    Diabetes Obesity and Metabolism 01/2015; · 5.18 Impact Factor
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    ABSTRACT: The ratio of glycated albumin to glycated hemoglobin (GA/A1c) is known to be elevated in subjects with type 2 diabetes mellitus (T2DM) who had decreased insulin secretion. Additionally, the carotid intima media thickness (IMT) is greater in T2DM patients with higher GA/A1c ratios. We investigated whether increased GA/A1c ratio and IMT are also associated in type 1 diabetes mellitus (T1DM), which is characterized by lack of insulin secretory capacity. In this cross-sectional study, we recruited 81 T1DM patients (33 men, 48 women; mean age 44.1±13.0 years) who underwent carotid IMT, GA, and HbA1c measurements. The mean GA/A1c ratio was 2.90. Based on these results, we classified the subjects into two groups: group I (GA/A1c ratio <2.90, n=36) and group II (GA/A1c ratio ≥2.90, n=45). Compared with group I, the body mass indexes (BMIs), waist circumferences, and IMTs were lower in group II. GA/A1c ratio was negatively correlated with BMI, urine albumin to creatinine ratio (P<0.001 for both), and both the mean and maximal IMT (P=0.001, both). However, after adjusting the confounding factors, we observed that IMT was no longer associated with GA/A1c ratio. In contrast to T2DM, IMT was not significantly related to GA/A1c ratio in the subjects with T1DM. This suggests that the correlations between GA/A1c ratio and the parameters known to be associated with atherosclerosis in T2DM could be manifested differently in T1DM. Further studies are needed to investigate these relationships in T1DM.
    Diabetes & metabolism journal 12/2014; 38(6):456-63.
  • Hye-Jin Yoon, Bong Soo Cha
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    ABSTRACT: Non-alcoholic fatty liver disease affects approximately one-third of the population worldwide, and its incidence continues to increase with the increasing prevalence of other metabolic disorders such as type 2 diabetes. As non-alcoholic fatty liver disease can progress to liver cirrhosis, its treatment is attracting greater attention. The pathogenesis of non-alcoholic fatty liver disease is closely associated with insulin resistance and dyslipidemia, especially hypertriglyceridemia. Increased serum levels of free fatty acid and glucose can cause oxidative stress in the liver and peripheral tissue, leading to ectopic fat accumulation, especially in the liver. In this review, we summarize the mechanism underlying the progression of hepatic steatosis to steatohepatitis and cirrhosis. We also discuss established drugs that are already being used to treat non-alcoholic fatty liver disease, in addition to newly discovered agents, with respect to their mechanisms of drug action, focusing mainly on hepatic insulin resistance. As well, we review clinical data that demonstrate the efficacy of these drugs, together with improvements in biochemical or histological parameters.
    World journal of hepatology. 11/2014; 6(11):800-811.
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    ABSTRACT: Metformin activates both PRKA and SIRT1. Furthermore, autophagy is induced by either the PRKA-MTOR-ULK1 or SIRT1-FOXO signaling pathways. We aimed to elucidate the mechanism by which metformin alleviates hepatosteatosis by examining the molecular interplay between SIRT1, PRKA, and autophagy. ob/ob mice were divided into 3 groups: one with ad libitum feeding of a standard chow diet, one with 300 mg/kg intraperitoneal metformin injections, and one with 3 g/d caloric restriction (CR) for a period of 4 wk. Primary hepatocytes or HepG2 cells were treated with oleic acid (OA) plus high glucose in the absence or presence of metformin. Both CR and metformin significantly improved body weight and glucose homeostasis, along with hepatic steatosis, in ob/ob mice. Furthermore, CR and metformin both upregulated SIRT1 expression and also stimulated autophagy induction and flux in vivo. Metformin also prevented OA with high glucose-induced suppression of both SIRT1 expression and SIRT1-dependent activation of autophagy machinery, thereby alleviating intracellular lipid accumulation in vitro. Interestingly, metformin treatment upregulated SIRT1 expression and activated PRKA even after siRNA-mediated knockdown of PRKAA1/2 and SIRT1, respectively. Taken together, these results suggest that metformin alleviates hepatic steatosis through PRKA-independent, SIRT1-mediated effects on the autophagy machinery.
    Autophagy 11/2014; · 11.42 Impact Factor
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    ABSTRACT: The National Health Insurance Service (NHIS) recently signed an agreement to provide limited open access to the databases within the Korean Diabetes Association for the benefit of Korean subjects with diabetes. Here, we present the history, structure, contents, and way to use data procurement in the Korean National Health Insurance (NHI) system for the benefit of Korean researchers.
    Diabetes & metabolism journal 10/2014; 38(5):395-403.
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    ABSTRACT: Glycated albumin (GA) has been increasingly used as a reliable index for short-term glycemic monitoring, and is inversely associated with β-cell function. Because the pathophysiologic nature of type 2 diabetes (T2D) is characterized by progressive decline in insulin secretion, the aim was to determine whether GA levels were affected by diabetes duration in subjects with T2D.
    PLoS ONE 09/2014; 9(9):e108772. · 3.53 Impact Factor
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    ABSTRACT: Sitagliptin is a novel antidiabetic agent with a low risk for hypoglycemia. We investigated the efficacy and safety of sitagliptin when patients switched from a sulfonylurea to sitagliptin and identified good candidates for the switch.
    Endocrinology and metabolism (Seoul, Korea). 09/2014;
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    ABSTRACT: 3-Hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) are used to control blood cholesterol levels and reduce cardiovascular disease. It has been repeatedly reported that statins may cause new-onset diabetes mellitus (DM). However, limited evidence exists from direct head to head comparisons of statins on whether the risk of DM differs among statins. We investigated the risk of development of new-onset diabetes in subjects treated with different statins.
    Metabolism: clinical and experimental 09/2014; · 3.61 Impact Factor
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    ABSTRACT: Non-alcoholic fatty liver disease (NAFLD) is a prevalent and rapidly increasing disease worldwide; however, no widely accepted screening models to assess the risk of NAFLD are available. Therefore, we aimed to develop and validate a self-assessment score for NAFLD in the general population using two independent cohorts.
    PLoS ONE 09/2014; 9(9):e107584. · 3.53 Impact Factor
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    ABSTRACT: We investigated the efficacy of cilostazol treatment for 2 years on the attenuation of carotid intima-media thickness (IMT) progression in type 2 diabetic patients without cardiovascular disease history, as compared with other antiplatelet agents. We recruited a total of 230 type 2 diabetic patients who had undergone IMT measurement twice within 1.5-2.5 years (mean 2.06 ± 0.32 years) interval. Among these participants, we classified them into three groups according to antiplatelet agent administration at baseline: Group I (n = 66), antiplatelet naïve; Group II (n = 75), other antiplatelet agent administration; and Group III (n = 50), cilostazol administration. We then analyzed the changes in clinical characteristics from baseline to 2 years. The changes in annual mean IMT at 2 years were 0.019 ± 0.045 mm/year, -0.001 ± 0.058 mm/year, and -0.019 ± 0.043 mm/year for Group I, II, and III, respectively (P < 0.001). Mean change in total cholesterol, low-density lipoprotein-cholesterol, and triglyceride compared with baseline decreased the most in Group III even after adjustment for statin use. We also observed that the odds ratio of carotid IMT progression at 2 years was the lowest in patients who were treated with cilostazol even after adjustment for change of metabolic parameters. When we categorized patients according to baseline carotid IMT tertile, the efficacy of cilostazol against carotid IMT progression was significant only when baseline IMT was over 0.662 mm (mean 0.801). Two-year treatment with cilostazol strongly inhibited carotid IMT progression compared to other antiplatelet agents in type 2 diabetic patients. This beneficial effect of cilostazol was significant when baseline IMT was thicker than 0.662 mm (mean 0.801 mm).
    Endocrine 09/2014; · 3.53 Impact Factor
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    ABSTRACT: AimsIn this study, we compared the glucose-lowering effectiveness of insulin analogues and their combination according to baseline glycemic status in patients with type 2 diabetes (T2D) from the A1chieve® study conducted in Korea.Methods This sub-analysis from the A1chieve® study was a 24-week prospective, multicenter, non-interventional, open-labelled study. Of the 4058 patients, 3074 patients who had their HbA1c level measured at baseline were included in this sub-analysis. We classified patients into three groups according to baseline HbA1c levels: group I (HbA1c < 7.5%), group II (7.5% ≤ HbA1c < 9.0%) and group III (HbA1c ≥ 9.0%).ResultsPatients in group I showed no significant HbA1c reduction with any insulin regimens (detemir, aspart, detemir and aspart or biphasic aspart 30 (Novo Nordisk A/S, DK-2880 Bagsværd, Denmark) after 24 weeks of treatment. In group II, although HbA1c was decreased for all insulin regimens, there was no difference in mean HbA1c reduction among the four insulin regimens. In patients with a high baseline HbA1c level (group III), mean HbA1c reduction was the greatest in patients on a basal-bolus regimen (detemir and aspart, −3.50%) and lowest in patients on a bolus regimen (aspart, −1.81%; p < 0.001).Conclusion For optimal glycaemic control, a basal-bolus regimen may be adequate for Korean patients with poorly controlled T2D (HbA1c ≥ 9.0%).
    International Journal of Clinical Practice 09/2014; · 2.54 Impact Factor
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    ABSTRACT: Glycated albumin (GA) reflects short term status of glycemic control. We suggest a GA cut-off value to diagnose pre-diabetes and diabetes in Korean adults. In addition, we compared the performance of GA for the diagnosis of diabetes with that of glycated hemoglobin (A1c) MATERIALS AND METHODS: A total of 852 subjects (498 males, 354 females) aged 20 to 83 y (mean 52.5 y) were enrolled. A 75-g oral glucose tolerance test (OGTT) was performed and A1c and GA were measured.
    Clinica Chimica Acta 07/2014; 437. · 2.76 Impact Factor
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    ABSTRACT: Objective We investigated whether KR-66195, a new synthetic dipeptidyl dipeptidase IV inhibitor, could prevent weight gain, as well as improving glycemic control in diet-induced obese (DIO) and ob/ob mice. Materials/Methods Male C57BL/6 mice were randomly assigned to the following groups: chow diet, high-fat diet, and high-fat diet with KR-66195. After KR-66195 treatment for eight weeks, intraperitoneal glucose tolerance tests were performed. A pair-feeding study was performed to investigate the mechanisms of the anti-obesity effects of KR-66195 in DIO mice. Female ob/ob mice were treated with KR-66195 for three weeks and compared to the vehicle-treated group. Results In DIO mice, KR-66195 treatment increased the plasma glucagon-like peptide (GLP)-1 levels and improved glucose tolerance. This treatment also reduced body weight gain (5.38 ± 0.94 g vs. 12.08 ± 0.55 g, P < 0.01) and food intake (2.41 ± 0.09 g vs. 2.79 ± 0.11 g, P < 0.05). In ob/ob mice, KR-66195 treatment for three weeks resulted in comparable effects in DIO mice. In the pair-feeding study, KR-66195-treated mice exhibited a 16% increase in energy expenditure (kcal/h/kg lean body mass) without significant differences in body weight or activities compared with pair-fed mice. These results suggest that KR-66195 prevented weight gain in DIO mice by decreasing food intake, as well as increasing energy expenditure. Conclusions KR-66195 markedly increased plasma levels of GLP-1, resulting in the probable improvement in glucose tolerance and reduced body weight and food intake. Thus, KR-66195 might be further developed as a therapeutic drug to treat obesity, as well as diabetes.
    Metabolism: clinical and experimental 06/2014; · 3.61 Impact Factor
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    ABSTRACT: We evaluated the effects of two dipeptidyl peptidase-4 (DPP-4) inhibitors, sitagliptin and vildagliptin, on metabolic parameters in patients with type 2 diabetes mellitus.
    Diabetes & metabolism journal 06/2014; 38(3):211-9.
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    ABSTRACT: Compared to the golden standard glycation index of HbA1c, glycated albumin (GA) has potentials for assessing insulin secretory dysfunction and glycemic fluctuation as well as predicting diabetic vascular complications. However, the reference ranges of GA and a conversion equation need to be clearly defined. We designed this study to determine the reference ranges in patients with normal glucose tolerance (NGT) based on conventional measures of glycemic status and to devise a conversion equation for calculating HbA1c and GA in a Korean population. In this multicenter, retrospective, cross-sectional study, we recruited antidiabetic drug-naïve patients with available glycemic variables including HbA1c, GA, and fasting plasma glucose regardless of glucose status. For the reference interval of serum GA, 5th to 95th percentile value of GA in subjects with NGT was adopted. The conversion equation between HbA1c and GA was devised using an estimating regression model with unknown break-points method. The reference range for GA was 9.0-14.0% in 2043 subjects. The 95th percentile responding values for FPG, and HbA1c were approximately 5.49 mmol/l, and 5.6%, respectively. The significant glycemic turning points were 5.868% HbA1c and 12.2% GA. The proposed conversion equation for below and above the turning point were GA (%) = 6.960+0.8963 × HbA1c (%) and GA (%) = -9.609+3.720 × HbA1c (%), respectively. These results should be helpful in future studies on the clinical implications of high GA relative to HbA1c and the clinical implementation of diabetes management.
    PLoS ONE 04/2014; 9(4):e95729. · 3.53 Impact Factor
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    ABSTRACT: The mortality rate from cardiovascular disease (CVD) among young adults has declined less than that in the older population, raising concerns about the increasing prevalence of obesity-related conditions including hypercholesterolemia in the younger population. We investigated the age-standardized mean levels of serum cholesterols and the prevalence, awareness, treatment and control rates of hyper-low-density lipoprotein (LDL)-cholesterolemia based on age. Nationally representative samples of 19 489 subjects aged ≥20 years were analyzed from the Korea National Health and Nutrition Examination Surveys 2008-2010. Hyper-LDL-cholesterolemia was individually evaluated by the 2004 National Cholesterol Education Program Adult Treatment Panel III guidelines. Age-standardized mean levels of total cholesterol, high-density lipoprotein-cholesterol, LDL-cholesterol, and triglycerides were 186.8, 48.0, 112.9, and 136.0 mg/dL, respectively. Age-standardized prevalence of hyper-LDL-cholesterolemia was 23.2% (men, 25.5%; women, 21.8%). Among subjects with hyper-LDL-cholesterolemia, awareness and treatment rates were significantly lower in younger adults (<50 years) compared to older adults ≥50 years (awareness, 8.0% versus 21.5%; treatment, 5.1% versus 18.5%, all Ps<0.001), indicating significant discrepancies in awareness and treatment rates of hypercholesterolemia between younger and older adults. Among subjects aware of their hyper-LDL-cholesterolemia, younger adults were more likely to have controlled LDL-cholesterol than the elderly (82.1% versus 67.5%, P<0.001). Compared to the elderly, significant proportions of young and middle-aged adults are unaware of their hypercholesterolemia and are not treated with proper lipid-lowering medications. Early screening, education, and proper management should be stressed in national public healthcare policies to reduce the increasing burden of CVD in the younger population with undiagnosed hypercholesterolemia.
    Journal of the American Heart Association. 04/2014; 3(1):446.
  • Endocrine Abstracts. 04/2014;
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    ABSTRACT: Aims/IntroductionTo compare the efficacy and safety of early combination therapy with glimepiride/metformin to metformin uptitration in reducing glycated hemoglobin (HbA1c) levels in Korean type 2 diabetic patients inadequately controlled on low-dose metformin monotherapy.Materials and Methods In a randomized, open label, parallel group, multicenter study, 209 Korean type 2 diabetic patients (HbA1c 7.0–10.0%, on metformin 500–1,000 mg/day) received glimepiride/metformin fixed-dose combination (G/M FDC) or metformin uptitration treatment (Met UP). The primary end-point was the change in HbA1c from baseline to week 24.ResultsG/M FDC therapy provided significantly greater adjusted mean decreases vs Met UP therapy in HbA1c (−1.2 vs −0.8%, P < 0.0001), and fasting plasma glucose (−35.7 vs −18.6 mg/dL, P < 0.0001). A significantly greater proportion of patients with G/M FDC therapy achieved HbA1c < 7% (74.7 vs 46.6%, P < 0.0001) at the end of the study. More patients experienced hypoglycemia with G/M FDC therapy compared with Met UP therapy (41 vs 5.6%, P < 0.0001), but there was no serious hypoglycemia in any group. A modest increase in mean bodyweight occurred in the patients who were treated with G/M FDC therapy (1.0 kg), whereas a slight decrease was observed in the patients who were treated with Met UP therapy (−0.7 kg).Conclusion The present study showed that glimepiride/metformin fixed-dose combination therapy was more effective in glycemic control than metformin uptitration, and was well tolerated in type 2 diabetic patients inadequately controlled by low-dose metformin monotherapy in Korea. This trial was registered with ClinicalTrial.gov (no. NCT00612144).
    Journal of Diabetes Investigation. 03/2014;
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    ABSTRACT: Glycated albumin to glycated hemoglobin (GA/A1c) ratio is known to be inversely related with body mass index (BMI) and insulin secretory capacity. However, the reasons for this association remain unknown. We aimed to investigate whether BMI directly or indirectly influences GA/A1c by exerting effects on insulin secretion or resistance and to confirm whether these associations differ according to glucose tolerance status. We analyzed a total of 807 subjects [242 drug-naïve type 2 diabetes (T2D), 378 prediabetes, and 187 normal glucose tolerance (NGT)]. To assess the direct and indirect effects of BMI on GA/A1c ratio, structural equation modeling (SEM) was performed. GA/A1c ratio was set as a dependent variable, BMI was used as the independent variable, and homeostasis model assessment-pancreatic beta-cell function (HOMA-β), homeostasis model assessment-insulin resistance (HOMA-IR), glucose level were used as mediator variables. The estimates of a direct effect of BMI on GA/A1c to be the strongest in NGT and weakest in T2D (-0.375 in NGT, -0.244 in prediabetes, and -0.189 in T2D). Conversely, the indirect effect of BMI on GA/A1c exerted through HOMA-β and HOMA-IR was not statistically significant in NGT group, but significant in prediabetes and T2D groups (0.089 in prediabetes, -0.003 in T2D). It was found that HOMA-β or HOMA-IR indirectly influences GA/A1c in T2D and prediabetes group through affecting fasting and postprandial glucose level. The relationship between GA/A1c and BMI is due to the direct effect of BMI on GA/A1c in NGT group, while in T2D and prediabetes groups, this association is mostly a result of BMI influencing blood glucose through insulin resistance or secretion.
    PLoS ONE 02/2014; 9(2):e89478. · 3.53 Impact Factor
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    ABSTRACT: Aims/IntroductionType 2 diabetes is characterized by progressive deterioration of β-cell function. Recently, it was suggested that the C-peptide-to-glucose ratio after oral glucose ingestion is a better predictor of β-cell mass than that during fasting. We investigated whether postprandial C-peptide-to-glucose ratio (PCGR) reflects β-cell function, and its clinical application for management of type 2 diabetes. Materials and Methods We carried out a two-step retrospective study of 919 Korean participants with type 2 diabetes. In the first step, we evaluated the correlation of PCGR level with various markers for β-cell function in newly diagnosed and drug-naïve patients after a mixed meal test. In the second step, participants with well-controlled diabetes (glycated hemoglobin
    Journal of Diabetes Investigation. 02/2014;

Publication Stats

2k Citations
545.23 Total Impact Points

Institutions

  • 2000–2014
    • Yonsei University Hospital
      • Department of Internal Medicine
      Sŏul, Seoul, South Korea
  • 1996–2014
    • Yonsei University
      • Department of Internal Medicine
      Sŏul, Seoul, South Korea
  • 2005–2013
    • Seoul National University Bundang Hospital
      Sŏul, Seoul, South Korea
    • Seoul National University Hospital
      • Department of Internal Medicine
      Seoul, Seoul, South Korea
  • 2009
    • Beth Israel Deaconess Medical Center
      Boston, Massachusetts, United States
  • 2007–2009
    • Ajou University
      • Department of Endocrinology and Metabolism
      Seoul, Seoul, South Korea
    • Myongji Hospital
      Kōyō, Gyeonggi Province, South Korea
  • 2008
    • Bundang Jesaeng Hospital
      Sŏngnam, Gyeonggi Province, South Korea
  • 2006–2008
    • Inha University Hospital
      Sinhyeon, South Gyeongsang, South Korea
  • 2003–2007
    • National Health Insurance Corporation Ilsan Hospital
      Sŏul, Seoul, South Korea