Yeun Sun Kim

RARITY OF TLR4 ASP299GLY AND THR399ILE POLYMORPHISMS IN THE KOREAN POPULATION

Purpose Activation of the innate immune system and chronic low-grade inflammation are thought to be involved in the pathogenesis of atherosclerosis and also thought to be associated with type 2 diabetes and its complications. As a receptor for bacterial lipopolysaccharide and heat-shock proteins, Toll-like receptor 4 (TLR4) is one of the central regulators of the immune response. Recent studies have reported an association between TLR4 polymorphisms and diabetes and its complications in Caucasian populations. Materials and Methods In this study, we analyzed the association between TLR4 gene polymorphisms in patients with features of type 2 diabetes and healthy controls in Korea. Two polymorphisms of the TLR4 gene (Asp299Gly and Thr399Ile) were examined in 225 diabetic patients and 153 healthy controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and single-strand conformation polymorphism (SSCP). Results No Asp299Gly or Thr399Ile mutations were detected in any of the 378 subjects. Seven subjects from each group who had slightly different SSCP patterns were selected for sequencing, but we found no TLR4 polymorphisms on Exon3. The Asp299Gly and Thr399Ile TLR4 gene polymorphisms were absent in both groups, which was similar to the results for Japanese and Chinese Han subjects. Conclusion Our data and other Asian data suggest that a racial difference can be found in the frequency of the TLR4 polymorphism.

Protective Effects of Vildagliptin against Pioglitazone-Induced Bone Loss in Type 2 Diabetic Rats

Long-term use of thiazolidinediones (TZDs) is associated with bone loss and an increased risk of fracture in patients with type 2 diabetes (T2DM). Incretin-based drugs (glucagon-like peptide-1 (GLP-1) agonists and dipeptidylpeptidase-4 (DPP-4) inhibitors) have several benefits in many systems in addition to glycemic control. In a previous study, we reported that exendin-4 might increase bone mineral density (BMD) by decreasing the expression of SOST/sclerostin in osteocytes in a T2DM animal model. In this study, we investigated the effects of a DPP-4 inhibitor on TZD-induced bone loss in a T2DM animal model. We randomly divided 12-week-old male Zucker Diabetic Fatty (ZDF) rats into four groups; control, vildagliptin, pioglitazone, and vildagliptin and pioglitazone combination. Animals in each group received the respective treatments for 5 weeks. We performed an intraperitoneal glucose tolerance test (IPGTT) before and after treatment. BMD and the trabecular micro-architecture were measured by DEXA and micro CT, respectively, at the end of the treatment. The circulating levels of active GLP-1, bone turnover markers, and sclerostin were assayed. Vildagliptin treatment significantly increased BMD and trabecular bone volume. The combination therapy restored BMD, trabecular bone volume, and trabecular bone thickness that were decreased by pioglitazone. The levels of the bone formation marker, osteocalcin, decreased and that of the bone resorption marker, tartrate-resistant acid phosphatase (TRAP) 5b increased in the pioglitazone group. These biomarkers were ameliorated and the pioglitazone-induced increase in sclerostin level was lowered to control values by the addition of vildagliptin. In conclusion, our results indicate that orally administered vildagliptin demonstrated a protective effect on pioglitazone-induced bone loss in a type 2 diabetic rat model.

Evaluation of Stress in Korean Patients with Diabetes Mellitus Using the Problem Areas in Diabetes-Korea Questionnaire

Background It is known that diabetes and stress are directly or indirectly related, and that it is important to evaluate stress in patients with diabetes. The relationship between Korean diabetics and diabetes-related stress has never been reported. The objective of this study was to develop a stress questionnaire suitable for use with Korean diabetics and to evaluate its utility. Methods This study subjects were 307 Korean diabetics, aged 40 to 74 years old, who visited the Department of Endocrinology and Metabolism at Gachon University Gil Hospital, Yeungnam University Medical Center, and Inha University Hospital in Korea between March 2006 and February 2008. We developed a Korean version of Polonskys Problem Areas in Diabetes (PAID) stress questionnaire (PAID-K) and used it to assess degrees of stress in our sample of Korean patients. We evaluated the utility of the questionnaire and analyzed the relationships between clinical characteristics of the study subjects and degrees of stress. Results Cronbachs alpha for PAID-K was 0.95, and PAID-K scores were significantly correlated with Hypoglycemia Fear Survey scores (r=0.44, P<0.05) and State Trait Anxiety Inventory-6 scores (r=0.21, P<0.05). PAID-K scores were significantly higher in patients with longer durations of diabetes, patients using insulin, and female patients (P=0.02, P=0.038, and P=0.001, respectively). The score also tended to increase as HbA1c levels increased, except for very high HbA1c levels (above 11%) (P for trend<0.05). Conclusion We developed the PAID-K questionnaire and demonstrated its utility to evaluate levels of stress in diabetic patients in Korea.

Genetic Analysis of Multiple Endocrine Neoplasia Type 1 (MEN1) Leads to Misdiagnosis of an Extremely Rare Presentation of Intrasellar Cavernous Hemangioma as MEN1

Background Multiple endocrine neoplasia type 1 (MEN1) is a rare inherited disorder characterized by the simultaneous occurrence of endocrine tumors in target tissues (mainly the pituitary, endocrine pancreas, and parathyroid glands). MEN1 is caused by mutations in the MEN1 gene, which functions as a tumor suppressor and consists of one untranslated exon and nine exons encoding the menin protein. This condition is usually suspected when we encounter patients diagnosed with tumors in multiple endocrine organs, as mentioned above. Methods A 65-year-old woman who underwent surgery for a pancreatic tumor (serous cystadenoma) 5 years previously was referred to our hospital due to neurologic symptoms of diplopia and left ptosis. Brain magnetic resonance imaging revealed a 3.4-cm lesion originating from the cavernous sinus wall and extending into the sellar region. It was thought to be a nonfunctioning tumor from the results of the combined pituitary function test. Incidentally, we found that she also had a pancreatic tumor, indicating the necessity of genetic analysis for MEN1. Results Genomic analysis using peripheral leukocytes revealed a heterozygous c.1621G>A mutation in the MEN1 gene that was previously reported to be either a pathogenic mutation or a simple polymorphism. We pursued a stereotactic approach to the pituitary lesion, and microscopic findings of the tumor revealed it to be an intrasellar cavernous hemangioma, a rare finding in the sellar region and even rarer in relation to oculomotor palsy. The patient recovered well from surgery, but refused further evaluation for the pancreatic lesion. Conclusion There is great emphasis placed on genetic testing in the diagnosis of MEN1, but herein we report a case where it did not assist in diagnosis, hence, further discussion on the role of genetic testing in this disease is needed. Also, in cases of pituitary tumor with cranial nerve palsy, despite its low prevalence, intrasellar cavernous hemangioma could be suspected.

Resolution of Metabolic Disorders and Overweight in a Patient with ACTH-independent Cushing’s Syndrome after Unilateral Adrenalectomy

Excessive production of cortisol by abnormal adrenocortical tissue causes clinical manifestations of Cushing’s syndrome and is associated with metabolic abnormalities including abdominal obesity, hyperglycemia, dyslipidemia, and hypertension, which increase the risk for type 2 diabetes mellitus as well as vascular morbidity and mortality. Removing the cause of hypercortisolism is initially required to resolve metabolic disorders in patients with adrenal Cushing’s syndrome. A 38-year-old woman with diabetes mellitus and hypertension, which were not well controlled by medications, complained of abdominal obesity, rounded face, thin limbs, and bruising. Based on clinical manifestations and laboratory findings, she was diagnosed with Cushing’s syndrome due to unilateral cortisol-producing adrenal adenoma. After left adrenalectomy, the patient’s blood glucose improved to a satisfactory level, and she rapidly discontinued insulin and oral glucose-lowering agent therapy. Her body mass index decreased to the normal range, and her other metabolic symptoms, dyslipidemia and hypertension, also improved significantly. She has maintained resolution of metabolic disorders and overweight for eight years since surgery without recurrence of Cushing’s syndrome.