Seong Bin Hong

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.

Dual blockade of the renin-angiotensin system with angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers in chronic kidney disease.

Despite the renoprotective effects of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs), many patients with chronic kidney disease develop end-stage kidney disease. Combination treatment with an ACEI and an ARB is a recently introduced approach to obtain more complete blockade of the renin–angiotensin system, based on the different mechanisms of action of the two classes of drug. To assess the shortcomings of single treatment with ACEIs and ARBs, and the potential benefits of combination treatment, we reviewed the experimental and clinical evidence suggesting that combination treatment offers more complete blockade of the renin–angiotensin system and identified areas in which further research is necessary to confirm the benefits of combination treatment. The available data suggest that combination treatment with an ACEI and an ARB has a greater renoprotective effect than either drug alone. In addition, more recent data have shown that combination treatment is more potent in suppressing renal fibrosis, and is well tolerated in patients with advanced chronic kidney disease. Clinical trials with rigorous endpoints are needed to further establish the benefits of combination treatment in renal protection.

Salivary gland function after sialendoscopy for treatment of chronic radioiodine-induced sialadenitis

The purpose of this study was to determine whether sialendoscopy could ameliorate radioactive iodine‐induced obstructive sialadenitis and restore the salivary gland dysfunction in recalcitrant radioactive iodine sialadenitis.

Effect of High Glucose on Basal Intracellular Calcium Regulation in Rat Mesangial Cell

Background: A number of cellular mechanisms are critically dependent on intracellular Ca²⁺ homeostasis. A sustained increase in the intracellular Ca²⁺ concentration ([Ca²⁺]_i) is capable of activating a number of potentially harmful processes including phenotype change to secretory type, dysregulated cell proliferation, and cell injury and death. Mesangial cells (MCs) play an important role in the pathophysiology of diabetic nephropathy. Methods: We evaluated the effect of high glucose on basal [Ca²⁺]_i in the unstimulated state and identified its contributing pathways. MCs were isolated and cultured from Sprague-Dawley rats. [Ca²⁺]_i was measured by fluorometric technique with fura-2AM. Results: In a dose-dependent manner, superfusion of MCs with Tyrode’s solution containing high glucose (30 and 50 mM) induced a delayed spontaneous increase in [Ca²⁺]_i, which was not found in those with normal (5.5 mM) glucose or mannitol. The high glucose-induced increase in [Ca²⁺]_ioccurred through transmembrane influx of extracellular Ca²⁺ and was blocked by SKF96365, an inhibitor of store-operated Ca²⁺ influx. Na⁺-Ca²⁺ exchanger (NCX) activity, a major channel regulating basal [Ca²⁺]_i, and the clearing ability of intracellular Ca²⁺ were depressed after MCs were cultured in high-glucose medium. Western blot analysis revealed the decreased expression of a 70-kD NCX protein in MCs cultured in high-glucose medium. Conclusions: A high-glucose concentration induced a spontaneous increase in basal [Ca²⁺]_i of MCs without stimulation. There was a decrease in the activity of NCX in the high-glucose condition, which seems to occur at the level of protein expression. The present results provide a novel insight into the mechanisms of diabetic nephropathy in that intracellular Ca²⁺ homeostasis is an important secondary messenger and a mediator in hormonal signaling.

Obesity and Hyperglycemia in Korean Men with Klinefelter Syndrome: The Korean Endocrine Society Registry

Background The aim of this study was to investigate the prevalence of obesity in Korean men with Klinefelter syndrome (KS) and the associated risk factors for obesity and hyperglycemia. Methods Data were collected retrospectively from medical records from 11 university hospitals in Korea between 1994 and 2014. Subjects aged ≥18 years with newly diagnosed KS were enrolled. The following parameters were recorded at baseline before treatment: chief complaint, height, weight, fasting glucose level, lipid panel, blood pressure, testosterone, luteinizing hormone, follicle-stimulating hormone, karyotyping patterns, and history of hypertension, diabetes, and dyslipidemia. Results Data were analyzed from 376 of 544 initially enrolled patients. The rate of the 47 XXY chromosomal pattern was 94.1%. The prevalence of obesity (body mass index ≥25 kg/m2) in Korean men with KS was 42.6%. The testosterone level was an independent risk factor for obesity and hyperglycemia. Conclusion Obesity is common in Korean men with KS. Hypogonadism in patients with KS was associated with obesity and hyperglycemia.

Association between nutrient intake and obesity in type 2 diabetic patients from the Korean National Diabetes Program: a cross-sectional study.

The aim of the study was to assess the association between usual dietary nutrient intake and obesity in Korean type 2 diabetic patients. We examined 2,832 type 2 diabetic patients from the Korean National Diabetes Program cohort who completed dietary assessment and clinical evaluation in this cross-sectional study. In men, higher dietary fiber intake was associated with a lower odds of being obese (Ptrend = 0.003) and in women, higher protein intake was associated with a lower odds of being obese (Ptrend = 0.03) after adjustment for age, diabetes duration, HbA1c, alcohol drinking, income, education level, and calorie intake. In men, higher fiber intake was associated with lower odds of obesity after further adjustment for diastolic blood pressure, physical activity, and possible confounding nutritional intake and medication. The multivariable adjusted odds ratio for the highest quintile of fiber intake was 0.37 (Ptrend < 0.001). In women, protein intake was not associated with obesity after further adjustment. In conclusion, higher intake of dietary fiber is associated with lower odds of being obese in type 2 diabetic men, suggesting a role for dietary fiber in the management and prevention of obesity in type 2 diabetes (ClinicalTrials.gov: NCT 01212198).

R1467H Variants of Rho Guanine Nucleotide Exchange Factor 11 (ARHGEF11) are Associated with Type 2 Diabetes Mellitus in Koreans

Background The human Rho guanine nucleotide exchange factor 11 (ARHGEF11) functions as an activator of Rho GTPases and is thought to influence insulin signaling. The R1467H variant of ARHGEF11 has been reported to be associated with susceptibility to type 2 diabetes mellitus (T2DM) in Western populations. Methods We investigated the effects of the R1467H variant on susceptibility to T2DM as well as related traits in a Korean population. We genotyped the R1467H (rs945508) of ARHGEF11 in 689 unrelated T2DM patients and 249 non-diabetic individuals and compared the clinical and biochemical characteristics according to different alleles. Results The H allele was significantly more frequent in T2DM cases than in controls (P = 0.037, 17.1% and 13.1%; respectively). H homozygocity was associated with a higher risk of T2DM compared to those with R/R or R/H genotype (odds ratio, 5.24; 95% confidence interval, 1.06 to 25.83; P = 0.042). The fasting plasma glucose, HbA1c, fasting insulin, HOMA2-IR and HOMA2-%β levels did not differ significantly between different genotypes. Conclusion Our study replicated associations of the ARHGEF11 polymorphism with increased risk of T2DM in a Korean population and thus supports previous data implicating a potential role of ARHGEF11 in the etiology of T2DM. Further studies revealing the underlying mechanism for this association are needed.

The effects of adiponectin and inflammatory cytokines on diabetic vascular complications in obese and non-obese patients with type 2 diabetes mellitus

AIMS To evaluate the associations between inflammatory cytokines and adiponectin and various vascular complications in type 2 diabetes mellitus (T2DM). METHODS A total of 761 patients with T2DM were divided into a non-obese group and an obese group to enable the effects of obesity and T2DM on vascular complications to be differentiated. The serum levels of circulating inflammatory cytokines, that is, tumor necrosis factor (TNF)-α, and interleukin (IL)-6, total adiponectin, and high molecular weight (HMW) adiponectin were measured, and carotid intima media thickness (IMT), the presence of carotid plaque, and the severities of retinopathy and nephropathy, were assessed. RESULTS The obese group had significantly lower serum total and HMW adiponectin levels than the non-obese group. In the obese group, serum levels of total and HMW adiponectin, and TNF-α were significantly higher in patients with proliferative retinopathy than in those without retinopathy after adjusting for covariates. In the non-obese group, only IL-6 levels were significantly higher in patients with proliferative retinopathy than in those without. Serum levels of total and HMW adiponectin were significantly higher in patients with macroalbuminuria than in those with normoalbuminuria. No significant difference of three cytokines levels were observed depending on the carotid IMT or the presence of plaque. Logistic regression analysis revealed that serum total adiponectin (OR=1.209, P=0.038), diabetes duration (OR=1.230, P=0.014), and HbA1c (OR=2.359, P=0.006) were significantly associated with proliferative retinopathy in the obese group. CONCLUSION The study shows total adiponectin may influence proliferative retinopathy in obese patient with T2DM.

The Effect of Lowering the Threshold for Diagnosis of Impaired Fasting Glucose

Purpose The aim of this study was to evaluate the effect of lowering the fasting plasma glucose (FPG) criteria for impaired fasting glucose (IFG) on the prevalence of IFG and the risk for the development of diabetes associated with IFG in Koreans. Materials and Methods A total of 7,211 subjects who had normal glucose tolerance (NGT) or IFG were recruited. Subjects were evaluated at baseline and after two years follow up. Clinical data including total cholesterol, FPG and blood pressure were examined. Results Lowering the criteria for IFG from 6.1 mmol/L (110 mg/dL) to 5.6 mmol/L (100 mg/dL) increased the prevalence of IFG from 6.6% (494 subjects) to 24.4% (1829 subjects). After the 2 years follow up period, 91 subjects (1.3%) developed diabetes. Twenty one (0.3%) subjects developed diabetes among 5,382 NGT subjects and 70 (3.8%) subjects developed diabetes among 1,829 IFG (5.6 - 7.0 mmol/L) subjects. Lowering the IFG threshold from 6.1 mmol/L to 5.6 mmol/L resulted in a 18.4% decrease in specificity and 23.9% increase in sensitivity for predicting diabetes. The baseline FPG for predicting the development of diabetes after 2 years at a point on the receiver operating characteristic curve that was closest to the ideal 100% sensitivity and 100% specificity was 5.7 mmol/L (103 mg/dL). Conclusion Lowering the FPG criterion of IFG should have benefits in predicting new onset type 2 diabetes mellitus in Koreans. The economic and health benefits of applying the new IFG criteria should be evaluated in future studies.

Case of concurrent Riedel's thyroiditis, acute suppurative thyroiditis, and micropapillary carcinoma.

Riedels thyroiditis (RT) is a rare chronic inflammatory disease of the thyroid gland. It is characterized by a fibroinflammatory process that partially destroys the gland and extends into adjacent neck structures. Its clinical manifestation can mask an accompanying thyroid neoplasm and can mimic invasive thyroid carcinoma. Therefore, diagnosis can be difficult prior to surgical removal of the thyroid, and histopathologic examination of the thyroid is necessary for a definite diagnosis. The concurrent presence of RT and other thyroid diseases has been reported. However, to our knowledge, the association of RT with acute suppurative thyroiditis and micropapillary carcinoma has not been reported. We report a rare case of concurrent RT, acute suppurative thyroiditis, and micropapillary carcinoma in a 48-year-old patient.