It is well known that both insulin resistance and decreased insulin secretory capacity are important factors in the pathogenesis of type 2 diabetes mellitus (T2DM). In addition to genetic factors, obesity and lipotoxicity can increase the risk of T2DM. Glucagon-like peptide 1 (GLP-1) receptor agonists are novel antidiabetic drugs with multiple effects. They can stimulate glucose-dependent insulin secretion, inhibit postprandial glucagon release, delay gastric emptying, and induce pancreatic β-cell proliferation. They can also reduce the weight of patients with T2DM and relieve lipotoxicity at the cellular level. Many intracellular targets of GLP-1 have been found, but more remain to be identified. Elucidating these targets could be a basis for developing new potential drugs. My colleagues and I have investigated new targets of GLP-1, with a particular focus on pancreatic β-cell lines and hepatic cell lines. Herein, I summarize the recent work from my laboratory, with profound gratitude for receiving the prestigious 2016 Namgok Award.
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Nonalcoholic fatty liver disease (NAFLD) is strongly associated with insulin resistance, obesity, and dyslipidemia. NAFLD encompasses a wide range of states from the simple accumulation of triglycerides in the hepatocytes to serious states accompanied by inflammation and fibrosis in the liver.
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Insulin-like growth factor binding proteins (IGFBPs) are major regulators of insulin-like growth factor bioavailability and activity in metabolic signaling. Seven IGFBP family isoforms have been identified. Recent studies have shown that IGFBPs play a pivotal role in metabolic signaling and disease, including the pathogenesis of obesity, diabetes, and cancer. Although many studies have documented the various roles played by IGFBPs, transcriptional regulation of IGFBPs is not well understood. In this review, we focus on the regulatory mechanisms of IGFBP gene expression, and we summarize the findings of transcription factor activity in the IGFBP promoter region.
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At the summer workshop of the Korean Endocrine Society held in 2016, some examples of protein experiments were discussed in the session entitled “All about working with proteins.” In contrast to what the title suggested, it was unrealistic to comprehensively discuss all protein analytical methods. Therefore, the goal was to outline protein experimental techniques that are useful in research or in bench work. In conversations with clinicians, however, I have always felt that researchers who do not engage in bench science have different demands than those who do. Protein research tools that are useful in bench science may not be very useful or effective in the diagnostic field. In this paper, I provide a general summary of the protein analytical methods that are used in basic scientific research, and describe how they can be applied in the diagnostic field.
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Hyperglycemia during chemotherapy occurs in approximately 10% to 30% of patients. Glucocorticoids and L-asparaginase are well known to cause acute hyperglycemia during chemotherapy. Long-term hyperglycemia is also frequently observed, especially in patients with hematologic malignancies treated with L-asparaginase-based regimens and total body irradiation. Glucocorticoid-induced hyperglycemia often develops because of increased insulin resistance, diminished insulin secretion, and exaggerated hepatic glucose output. Screening strategies for this condition include random glucose testing, hemoglobin A1c testing, oral glucose loading, and fasting plasma glucose screens. The management of hyperglycemia starts with insulin or sulfonylurea, depending on the type, dose, and delivery of the glucocorticoid formulation. Mammalian target of rapamycin (mTOR) inhibitors are associated with a high incidence of hyperglycemia, ranging from 13% to 50%. Immunotherapy, such as anti-programmed death 1 (PD-1) antibody treatment, induces hyperglycemia with a prevalence of 0.1%. The proposed mechanism of immunotherapy-induced hyperglycemia is an autoimmune process (insulitis). Withdrawal of the PD-1 inhibitor is the primary treatment for severe hyperglycemia. The efficacy of glucocorticoid therapy is not fully established and the decision to resume PD-1 inhibitor therapy depends on the severity of the hyperglycemia. Diabetic patients should achieve optimized glycemic control before initiating treatment, and glucose levels should be monitored periodically in patients initiating mTOR inhibitor or PD-1 inhibitor therapy. With regard to hyperglycemia caused by anti-cancer therapy, frequent monitoring and proper management are important for promoting the efficacy of anti-cancer therapy and improving patients' quality of life.
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The prevalence of hypercholesterolemia in Koreans 30 years old and over was 19.5% in 2015 according to the Korean Nutrition and Health Examination Survey, which means that one-fifth of adults had hypercholesterolemia. The prevalence of hypertriglyceridemia in adults 30 years of age and older was 16.8% in 2015, and men had a 2-fold higher prevalence of hypertriglyceridemia than women (23.9% vs. 10.4%). The awareness of hypercholesterolemia in Koreans was higher in women than among men (62.4% vs. 51.4%). It increased with age; the level of awareness in participants 30 to 49 years of age (32.1% in men and 32.6% in women) was less than half of that observed among respondents ≥65 years old (77.5% in men and 78.0% in women). Regular check-ups for dyslipidemia and the active management thereof are urgent in Korean men aged 30 to 49. In women, the perimenopausal period is crucial for the prevention and management of metabolic syndrome, including dyslipidemia. Overall, improvements in awareness and treatment in the age group of 30 to 49 years in both men and women remain necessary.
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In recent studies, the reported prevalence of heterozygous familial hypercholesterolemia (FH) has been higher than in previous reports. Although cascade genetic screening is a good option for efficient identification of affected patients, diagnosis using only clinical criteria is more common in real clinical practice. Cardiovascular risk is much higher in FH patients due to longstanding low density lipoprotein cholesterol (LDL-C) burden and is also influenced by other risk factors. Although guidelines emphasize aggressive LDL-C reduction, the majority of patients cannot reach the LDL-C goal by conventional pharmacotherapy. Novel therapeutics such as proprotein convertase subtilisin/kexin type 9 inhibitors have shown strong lipid lowering efficacy and are expected to improve treatment results in FH patients.
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Macrophage cholesterol efflux is a central step in reverse cholesterol transport, which helps to maintain cholesterol homeostasis and to reduce atherosclerosis. Lipophagy has recently been identified as a new step in cholesterol ester hydrolysis that regulates cholesterol efflux, since it mobilizes cholesterol from lipid droplets of macrophages via autophagy and lysosomes. In this review, we briefly discuss recent advances regarding the mechanisms of the cholesterol efflux pathway in macrophage foam cells, and present lipophagy as a therapeutic target in the treatment of atherosclerosis.
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Over the last two decades coronary artery calcium (CAC) scanning has emerged as a quick, safe, and inexpensive method to detect the presence of coronary atherosclerosis. Data from multiple studies has shown that compared to individuals who do not have any coronary calcifications, those with severe calcifications (i.e., CAC score >300) have a 10-fold increase in their risk of coronary heart disease events and cardiovascular disease. Conversely, those that have a CAC of 0 have a very low event rate (~0.1%/year), with data that now extends to 15 years in some studies. Thus, the most notable implication of identifying CAC in individuals who do not have known cardiovascular disease is that it allows targeting of more aggressive therapies to those who have the highest risk of having future events. Such identification of risk is especially important for individuals who are not on any therapies for coronary heart disease, or when intensification of treatment is being considered but has an uncertain role. This review will highlight some of the recent data on CAC testing, while focusing on the implications of those findings on patient management. The evolving role of CAC in patients with diabetes will also be highlighted.
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Hypoparathyroid patients often have a higher bone mineral density (BMD) than the general population. However, an increase in BMD does not necessarily correlate with a solid bone microstructure. This study aimed to evaluate the bone microstructure of hypoparathyroid patients by using hip structure analysis (HSA).
Ninety-five hypoparathyroid patients >20 years old were enrolled and 31 of them had eligible data for analyzing bone geometry parameters using HSA. And among the control data, we extracted sex-, age-, and body mass index-matched three control subjects to each patient. The BMD data were reviewed retrospectively and the bone geometry parameters of the patients were analyzed by HSA.
The mean Z-scores of hypoparathyroid patients at the lumbar spine, femoral neck, and total hip were above zero (0.63±1.17, 0.48±1.13, and 0.62±1.10, respectively). The differences in bone geometric parameters were site specific. At the femoral neck and intertrochanter, the cross-sectional area (CSA) and cortical thickness (C.th) were higher, whereas the buckling ratio (BR) was lower than in controls. However, those trends were opposite at the femoral shaft; that is, the CSA and C.th were low and the BR was high.
Our study shows the site-specific effects of hypoparathyroidism on the bone. Differences in bone components, marrow composition, or modeling based bone formation may explain these findings. However, further studies are warranted to investigate the mechanism, and its relation to fracture risk.
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Several authors have questioned the accuracy of fine-needle aspiration cytology (FNAC) in large nodules. Some surgeons recommend thyroidectomy for nodules ≥4 cm even in the setting of benign FNAC, due to increased risk of malignancy and increased false negative rates in large thyroid nodules. The goal of our study was to evaluate if thyroid nodule size is associated with risk of malignancy, and to evaluate the false negative rate of FNAC for thyroid nodules ≥4 cm in our patient population.
This is a retrospective study of 85 patients with 101 thyroid nodules, who underwent thyroidectomy for thyroid nodules measuring ≥4 cm.
The overall risk of malignancy in nodules ≥4 cm was 9.9%. Nodule size was not associated with risk of malignancy (odds ratio, 1.02) after adjusting for nodule consistency, age, and sex (
Nodule size was not associated with risk of malignancy in nodules ≥4 cm in our patient population. FNAC had a false negative rate of 0. Patients with thyroid nodules ≥4 cm and benign cytology should not automatically undergo thyroidectomy.
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Adrenal insufficiency (AI) is a life-threatening disorder caused by the deficiency of adrenal steroid hormones. This retrospective cross-sectional study investigated the characteristics of patients with AI in Korea.
All consecutive patients with suspected AI who received care at a tertiary referral center in Korea in 2014 and underwent adrenocorticotropic hormone stimulation or insulin-tolerance testing were identified through a review of medical charts. Patients diagnosed with AI were enrolled. Their demographic, clinical, and treatment details were extracted.
Of 771 patients with suspected AI, 183 (23.7%) received a definitive diagnosis. The most common reason for testing was the presence of suspicious AI-related symptoms (30.0%), followed by a history of steroid medications (23.5%). Their mean age was 66.7 years, and females predominated (67.8%). The most common symptoms were general weakness, anorexia, arthralgia, and fever. Approximately half (53.6%) had a history of steroid use. Hydrocortisone was the most common treatment (71.6%), with most patients taking a 30 mg dose (44.2%). The most common dose frequency was twice a day (78.6%). Fourteen patients were treated for adrenal crisis (
AI may have been caused by steroid medication use in many of the patients included in this study. The detection of AI can be improved by careful history-taking and being alert to the possibility that a patient has used steroids.
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The increasing use of electronic medical record (EMR) systems for documenting clinical medical data has led to EMR data being increasingly accessed for clinical trials. In this study, a database of patients who were prescribed statins for the first time was developed using EMR data. A clinical data mart (CDM) was developed for cohort study researchers.
Seoul St. Mary's Hospital implemented a clinical data warehouse (CDW) of data for ~2.8 million patients, 47 million prescription events, and laboratory results for 150 million cases. We developed a research database from a subset of the data on the basis of a study protocol. Data for patients who were prescribed a statin for the first time (between the period from January 1, 2009 to December 31, 2015), including personal data, laboratory data, diagnoses, and medications, were extracted.
We extracted initial clinical data of statin from a CDW that was established to support clinical studies; the data was refined through a data quality management process. Data for 21,368 patients who were prescribed statins for the first time were extracted. We extracted data every 3 months for a period of 1 year. A total of 17 different statins were extracted. It was found that statins were first prescribed by the endocrinology department in most cases (69%, 14,865/21,368).
Study researchers can use our CDM for statins. Our EMR data for statins is useful for investigating the effectiveness of treatments and exploring new information on statins. Using EMR is advantageous for compiling an adequate study cohort in a short period.
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