γ-Linolenic Acid versus α-Lipoic Acid for Treating PainfulDiabetic Neuropathy in Adults: A 12-Week, Double-Placebo, Randomized, NoninferiorityTrial

BackgroundThis study was a multicenter, parallel-group, double-blind, double-dummy, randomized,noninferiority trial to evaluate the efficacy and safety of γ-linolenic acid(GLA) relative to α-lipoic acid (ALA) over a 12-week treatment period in type 2diabetes mellitus (T2DM) patients with painful diabetic peripheral neuropathy (DPN).MethodsThis study included 100 T2DM patients between 20 and 75 years of age who had painfulDPN and received either GLA (320 mg/day) and placebo or ALA (600 mg/day) and placebo for12 weeks. The primary outcome measures were mean changes in pain intensities as measuredby the visual analogue scale (VAS) and the total symptom scores (TSS).ResultsOf the 100 subjects who initially participated in the study, 73 completed the 12-weektreatment period. Per-protocol analyses revealed significant decreases in the mean VASand TSS scores compared to baseline in both groups, but there were no significantdifferences between the groups. The treatment difference for the VAS (95% confidenceinterval [CI]) between the two groups was −0.65 (−1.526 to 0.213) and theupper bound of the 95% CI did not exceed the predefined noninferiority margin(δ1=0.51). For the TSS, the treatment difference was −0.05(−1.211 to 1.101) but the upper bound of the 95% CI crossed the noninferioritymargin (δ2=0.054). There were no serious adverse events associatedwith the treatments.ConclusionGLA treatment in patients with painful DPN was noninferior to ALA in terms of reducingpain intensity measured by the VAS over 12 weeks.

Risk factors for hypothyroidism in euthyroid thyroid nodule patients with lymphocytic thyroiditis on fine needle aspiration cytology

BACKGROUND/AIMS@#Lymphocytic thyroiditis as cytology diagnosis from fine needle aspiration (FNA) is frequently detected in patients with thyroid nodules. However, the clinical outcome for upcoming hypothyroid events has been rarely clarified in euthyroid patients.@*METHODS@#We retrospectively reviewed the data of patient who had lymphocytic thyroitidis on FNA cytology of thyroid nodule from January 2005 to December 2010 at a tertiary referral hospital. In total, 109 patients with follow-up thyroid function tests (TFT) were enrolled. Final outcomes included overt and subclinical hypothyroidism with thyroid stimulating hormone (TSH) levels ≥ 10 mIU/L. Potential parameters predicting clinical hypothyroidism were analyzed by multivariate analysis.@*RESULTS@#Over the mean follow-up duration of 51.6 months, 14 out of 109 patients (12.8%) developed clinical hypothyroidism that required thyroid hormone replacement. The median onset time to hypothyroidism was 16 months (range, 3 to 88) and ≥ 60% of patients experienced clinical hypothyroidism within 1 year. By multivariate analysis, background thyroiditis (relative risk [RR], 9.78; p = 0.004), thyroid peroxidase antibody positivity (RR, 9.90; p = 0.003), nodule size (RR, 1.24; p < 0.001), and initial TSH (RR, 1.47; p = 0.009) were the independent risk factors for predicting hypothyroidism in euthyroid patients.@*CONCLUSIONS@#Hypothyroidism frequently occurs during the follow-up in euthyroid patients with thyroid nodules which show lymphocytic thyroiditis on FNA cytology. Close surveillance and regular TFT are needed in high-risk patients for upcoming clinical hypothyroidism.

Cardiovascular Autonomic Neuropathy Predicts Higher HbA1c Variability in Subjects with Type 2 Diabetes Mellitus

BACKGROUND: This study aimed to investigate the association between the presence and severity of cardiovascular autonomic neuropathy (CAN) and development of long-term glucose fluctuation in subjects with type 2 diabetes mellitus. METHODS: In this retrospective cohort study, subjects with type 2 diabetes mellitus who received cardiovascular autonomic reflex tests (CARTs) at baseline and at least 4-year of follow-up with ≥6 measures of glycosylated hemoglobin (HbA1c) were included. The severity of CAN was categorized as normal, early, or severe CAN according to the CARTs score. HbA1c variability was measured as the standard deviation (SD), coefficient of variation, and adjusted SD of serial HbA1c measurements. RESULTS: A total of 681 subjects were analyzed (294 normal, 318 early, and 69 severe CAN). The HbA1c variability index values showed a positive relationship with the severity of CAN. Multivariable logistic regression analysis showed that CAN was significantly associated with the risk of developing higher HbA1c variability (SD) after adjusting for age, sex, body mass index, diabetes duration, mean HbA1c, heart rate, glomerular filtration rate, diabetic retinopathy, coronary artery disease, insulin use, and anti-hypertensive medication (early CAN: odds ratio [OR], 1.65; 95% confidence interval [CI], 1.12 to 2.43) (severe CAN: OR, 2.86; 95% CI, 1.47 to 5.56). This association was more prominent in subjects who had a longer duration of diabetes (>10 years) and lower mean HbA1c ( < 7%). CONCLUSION: CAN is an independent risk factor for future higher HbA1c variability in subjects with type 2 diabetes mellitus. Tailored therapy for stabilizing glucose fluctuation should be emphasized in subjects with CAN.

Effects of High-Dose α-Lipoic Acid on Heart Rate Variability of Type 2 Diabetes Mellitus Patients with Cardiac Autonomic Neuropathy in Korea

BACKGROUND: Diabetic cardiac autonomic neuropathy (CAN) is one of the important complications of diabetes. It is characterized by reduced heart rate variability (HRV). METHODS: In this randomized, double-blind, placebo-controlled, multicenter trial, 75 patients were randomly assigned to one of two groups. One group (n=41) received α-lipoic acid (ALA) at an oral dose of 600 mg/day for the first 12 weeks and then 1,200 mg/day for the next 12 weeks. The other group (n=34) received placebo treatment for 24 weeks. CAN was assessed by measuring HRVs in people with diabetes. RESULTS: Most of the baseline measures for HRVs were similar between the ALA and placebo groups. Although there were no statistically significant HRV changes in the ALA group compared to the placebo group after 24 weeks of trial, we found a positive tendency in some of the HRV parameters of the ALA group. The standard deviations of normal-to-normal RR intervals in the standing position increased by 1.87 ms in the ALA group but decreased by −3.97 ms in the placebo group (P=0.06). The power spectrum of the low frequency (LF) band in the standing position increased by 15.77 ms² in the ALA group, whereas it declined by −15.04 ms² in the placebo group (P=0.08). The high frequency/LF ratio in the upright position increased by 0.35 in the ALA group, whereas it declined by −0.42 in the placebo group (P=0.06). There were no differences between the two groups regarding rates of adverse events. CONCLUSION: Although a slight improvement tendency was seen in HRV in the ALA group, there were no statistically significant HRV changes in the ALA group compared to the placebo group after 24 weeks of trial. However, the high oral dose of ALA was well-tolerated.

Physician-Directed Diabetes Education without a Medication Change and Associated Patient Outcomes

BACKGROUND: When patients with diabetes mellitus (DM) are first referred to a hospital from primary health care clinics, physicians have to decide whether to administer an oral hypoglycemic agent (OHA) immediately or postpone a medication change in favor of diabetes education regarding diet or exercise. The aim of this study was to determine the effect of diabetes education alone (without alterations in diabetes medication) on blood glucose levels. METHODS: The study was conducted between January 2009 and December 2013 and included patients with DM. The glycosylated hemoglobin (HbA1c) levels were evaluated at the first visit and after 3 months. During the first medical examination, a designated doctor also conducted a diabetes education session that mainly covered dietary management. RESULTS: Patients were divided into those who received no diabetic medications (n=66) and those who received an OHA (n=124). Education resulted in a marked decrease in HbA1c levels in the OHA group among patients who had DM for 10 years showed a slightly lower HbA1c target achievement rate of <6.5% (odds ratio, 0.089; P=0.0024). CONCLUSION: For patients who had DM for more than 5 years, higher doses or changes in medication were more effective than intensive active education. Therefore, individualized and customized education are needed for these patients. For patients with a shorter duration of DM, it may be more effective to provide initial intensive education for diabetes before prescribing medicines, such as OHAs.

Response: Effects of High-Dose α-Lipoic Acid on Heart Rate Variability of Type 2 Diabetes Mellitus Patients with Cardiac Autonomic Neuropathy in Korea (Diabetes Metab J 2017;41:275-83)

No abstract available.

Relationship between metabolic syndrome and thyroid nodules in healthy Koreans

BACKGROUND/AIMS: This study evaluated the relationship between thyroid nodules and metabolic syndrome (MS) and its components in apparently healthy Koreans. METHODS: We reviewed the records of 3,298 subjects with no noticeable symptoms who underwent thyroid ultrasound imaging as part of a routine check-up between July 2009 and June 2010; of these, 1,308 were excluded based upon predefined criteria. Among the remaining 1,990 patients, we examined the association between MS and its components and the incidence of thyroid nodules. RESULTS: Of the 1,990 subjects included in this study, 38.4% (n = 764) had thyroid nodules and 12.7% (n = 253) had MS. Female sex, older age, higher body mass index, larger waist circumference, higher glycated hemoglobin level, lower thyroid stimulating hormone level, and presence of MS were all closely related with the presence of thyroid nodules (all p < 0.05). Furthermore, the relevant number of MS components showed a positive linear correlation with the occurrence of thyroid nodules (p < 0.001). Evidence of MS alone was not independently associated with thyroid nodules after adjusting for sex and age in a multivariate binary logistic regression analysis; however, glycated hemoglobin for females and waist circumference for males, as well as both age and thyroid stimulating hormone for all patients, were identified as independent predictors for the existence of thyroid nodules (all p < 0.05). CONCLUSIONS: This study suggests a positive relationship between the components of MS and thyroid nodules in an ostensibly healthy Korean population. Our data support the idea that the recent increase in thyroid nodules is partly due to increases in both MS and obesity.

High glucose and palmitate increases bone morphogenic protein 4 expression in human endothelial cells

Here, we investigated whether hyperglycemia and/or free fatty acids (palmitate, PAL) aff ect the expression level of bone morphogenic protein 4 (BMP4), a proatherogenic marker, in endothelial cells and the potential role of BMP4 in diabetic vascular complications. To measure BMP4 expression, human umbilical vein endothelial cells (HUVECs) were exposed to high glucose concentrations and/or PAL for 24 or 72 h, and the effects of these treatments on the expression levels of adhesion molecules and reactive oxygen species (ROS) were examined. BMP4 loss-of-function status was achieved via transfection of a BMP4-specific siRNA. High glucose levels increased BMP4 expression in HUVECs in a dose-dependent manner. PAL potentiated such expression. The levels of adhesion molecules and ROS production increased upon treatment with high glucose and/or PAL, but this eff ect was negated when BMP4 was knocked down via siRNA. Signaling of BMP4, a proinflammatory and pro-atherogenic cytokine marker, was increased by hyperglycemia and PAL. BMP4 induced the expression of infl ammatory adhesion molecules and ROS production. Our work suggests that BMP4 plays a role in atherogenesis induced by high glucose levels and/or PAL.

Effects of 6-Month Sitagliptin Treatment on Insulin and Glucagon Responses in Korean Patients with Type 2 Diabetes Mellitus

BACKGROUND: This study aimed to evaluate the effect of sitagliptin, an oral dipeptidyl peptidase-4 inhibitor, on insulin secretion and glucagon suppression in Korean subjects with type 2 diabetes mellitus. METHODS: Twenty-four subjects underwent a 75-g oral glucose tolerance test (OGTT) before and after 6 months of sitagliptin treatment. Sitagliptin, insulin, and sulfonylurea were withdrawn for 3 days before OGTT to eliminate any acute effects on beta-cell insulin or alpha-cell glucagon secretion. Venous samples were drawn five times during each OGTT to measure plasma glucose, insulin, and glucagon. Indices on insulin secretion and resistance were calculated. RESULTS: Early phase insulin secretion, measured by the insulinogenic index significantly increased after 6 months of sitagliptin treatment, especially in the higher baseline body mass index group and higher baseline glycosylated hemoglobin (HbA1c) group. There were no significant differences in the insulin resistance indices before and after sitagliptin treatment. Although no significant differences were observed in the absolute levels of glucagon and the glucagon-to-insulin ratio, there was a significant reduction in the percentile change of glucagon-to-insulin ratio at 30- and 120-minute during the OGTT. CONCLUSION: Although the HbA1c level did not decrease significantly after 6 months of sitagliptin treatment, an increase in insulin secretion and reduction in early phase postprandial plasma glucagon-to-insulin ratio excursion was confirmed in Korean subjects with type 2 diabetes.

Refractory Graves' Disease Successfully Cured by Adjunctive Cholestyramine and Subsequent Total Thyroidectomy

The three major forms of treatment for Graves thyrotoxicosis are antithyroid drugs, radioactive iodine therapy and thyroidectomy. Surgery is the definitive treatment for Graves thyrotoxicosis that is generally recommended when other treatments have failed or are contraindicated. Generally, thyrotoxic patients should be euthyroid before surgery to minimize potential complications which usually requires preoperative management with thionamides or inorganic iodine. But several cases of refractory Graves' disease have shown resistance to conventional treatment. Here we report a 40-year-old female patient with Graves' disease who complained of thyrotoxic symptoms for 7 months. Her thyroid function test and thyroid autoantibody profiles were consistent with Graves' disease. One kind of thionamides and beta-blocker were started to control her disease. However, she was resistant to nearly all conventional medical therapies, including beta-blockers, inorganic iodine, and two thionamides. She experienced hepatotoxicity from the thionamides. What was worse is her past history of serious allergic reaction to corticosteroids, which are often used to help control symptoms. A 2-week regimen of high-dose cholestyramine improved her uncontrolled thyrotoxicosis and subsequent thyroidectomy was successfully performed. In conclusion, cholestyramine could be administered as an effective and safe adjunctive agent for preoperative preparation in patients with severe hyperthyroid Graves's disease that is resistant to conventional therapies.

Higher Prevalence and Awareness, but Lower Control Rate of Hypertension in Patients with Diabetes than General Population: The Fifth Korean National Health and Nutrition Examination Survey in 2011

BACKGROUND: We investigated the prevalence, awareness, treatment, and control rate of hypertension in Korean adults with diabetes using nationally representative data. METHODS: Using data of 5,105 adults from the fifth Korea National Health and Nutrition Examination Survey in 2011 (4,389 nondiabetes mellitus [non-DM]), 242 newly diagnosed with DM (new-DM), and 474 previously diagnosed with DM (known-DM), we analyzed the prevalence of hypertension (mean systolic blood pressure > or =140 mm Hg, diastolic blood pressure > or =90 mm Hg, or use of antihypertensive medication) and control rate of hypertension (blood pressure [BP] <130/80 mm Hg). RESULTS: The prevalence of hypertension in diabetic adults was 54.6% (44.4% in new-DM and 62.6% in known-DM, P<0.0001 and P<0.0001, respectively) compared with non-DM adults (26.2%). Compared to non-DM, awareness (85.7%, P<0.001) and treatment (97.0%, P=0.020) rates were higher in known-DM, whereas no differences were found between new-DM and non-DM. Control rate among all hypertensive subjects was lower in new-DM (14.9%), compared to non-DM (35.1%, P<0.001) and known-DM (33.3%, P=0.004). Control rate among treated subjects was also lower in new-DM (25.2%), compared to non-DM (68.4%, P<0.0001) and known-DM (39.9%, P<0.0001). CONCLUSION: Higher prevalence and low control rate of hypertension in adults with diabetes suggest that stringent efforts are needed to control BP in patients with diabetes, particularly in newly diagnosed diabetic patients.

Current Status of Glycemic Control of Patients with Diabetes in Korea: The Fifth Korea National Health and Nutrition Examination Survey

BACKGROUND: The Korea National Health and Nutrition Examination Survey (KNHANES) III (2005) reported that 22.9% of individuals with diabetes have a glycated hemoglobin (HbA1c) or =30 years with diabetes, we excluded 157 individuals who were missing HbA1c data. A total of 1,341 subjects were included in the final analysis. RESULTS: The prevalence of known diabetes was 7.7% (n=1,498, estimated to be 2.32 million people). The proportions of well-controlled diabetes meeting a HbA1c goal of 5 years. HbA1c in the group taking only oral hypoglycemic agents (OHAs) was significantly lower than that in the group administered only insulin or OHA and insulin in combination. In logistic regression analysis, a longer duration of diabetes, insulin use and the absence of chronic renal failure were associated with HbA1c levels >6.5%. CONCLUSION: The level of adequate glycemic control was similar to but slightly improved compared with previous levels. The glycemic control of long-standing diabetes patients is more difficult even though they receive insulin treatment.

Prevalence and Determinants of Diabetic Nephropathy in Korea: Korea National Health and Nutrition Examination Survey

BACKGROUND: Diabetic nephropathy is a leading cause of end stage renal disease and is associated with an increased risk of cardiovascular mortality. It manifests as albuminuria or impaired glomerular filtration rate (GFR), and the prevalence of diabetic nephropathy varies with ethnicity. The prevalence of diabetic nephropathy and its determinants in Korean adults have not previously been studied at the national level. This cross-sectional study was undertaken to ascertain the prevalence and determinants of albuminuria and chronic kidney disease (CKD) in Korean patients with diabetes. METHODS: The Korea National Health and Nutrition Examination Survey (KNHANES) V, conducted in 2011, was used to define albuminuria (n=4,652), and the dataset of KNHANES IV-V (2008-2011) was used to define CKD (n=21,521). Selected samples were weighted to represent the entire civilian population in Korea. Albuminuria was defined as a spot urine albumin/creatinine ratio >30 mg/g. CKD was defined as a GFR <60 mL/min/1.73 m2. RESULTS: Among subjects with diabetes, 26.7% had albuminuria, and 8.6% had CKD. Diabetes was associated with an approximate 2.5-fold increased risk of albuminuria, with virtually no difference between new-onset and previously diagnosed diabetes. Only systolic blood pressure was significantly associated with albuminuria, and old age, high serum triglyceride levels, and previous cardiovascular disease (CVD) were related with CKD in subjects with diabetes. CONCLUSION: Korean subjects with diabetes had a higher prevalence of albuminuria and CKD than those without diabetes. Blood pressure was associated with albuminuria, and age, triglyceride level, and previous CVD were independent determinants of CKD in subjects with diabetes.

Accelerated Disease Progression after Discontinuation of Sorafenib in a Patient with Metastatic Papillary Thyroid Cancer

Distant metastases from papillary thyroid carcinoma (PTC) are rare and are associated with a poor prognosis. Here, we describe a patient with metastatic PTC who was treated with a tyrosine kinase inhibitor (TKI, sorafenib) for several months that was acutely exacerbated by discontinuation. A 43-year-old male was diagnosed with PTC in February 2004 and underwent total thyroidectomy followed by two courses of high-dose radioactive iodine (RAI) therapy. Despite two additional courses of high-dose RAI therapy, lung and muscle metastases were developed. Treatment with sorafenib was begun in September 2010. After 11 months treatment of sorafenib, newly developed metastatic lesions were found in mediastinal lymph nodes, liver, and bones. Considered as treatment failure, the administration of sorafenib was discontinued. Two weeks after sorafenib treatment was stopped, the disease progressed abruptly and caused death of the patient by respiratory failure. In our patient, PTC progressed rapidly after the cessation of sorafenib treatment. Patients with several other types of cancer have also experienced such rapid disease progression, termed "flare-ups." Physicians should be aware that flare-ups may occur in advanced PTC patients following the cessation of TKI therapy.

Prevalence, Awareness, and Management of Obesity in Korea: Data from the Korea National Health and Nutrition Examination Survey (1998-2011)

BACKGROUND: Obesity is a risk factor for diabetes and several cardiovascular diseases. This study was to investigate the trends in the prevalence, awareness, and management status of obesity among the Korean population for recent 13 years. METHODS: The prevalence, subjective awareness, and management of obesity were investigated in adults aged > or =19 years by using the data from the Korea National Health and Nutrition Examination Surveys (KNHANES) 1998 to 2011. RESULTS: The number of participants was 8,117, 5,826, 5,500, 3,025, 6,756, 7,506, 6,255, and 6,155 in the KNHANES in years 1998, 2001, 2005, 2007, 2008, 2009, 2010, and 2011, respectively. The prevalence of obesity was 26.9%, 29.2%, 32.9%, 32.5%, 32.0%, 32.6%, 32.0%, and 32.0% in 1998, 2001, 2005, 2007, 2008, 2009, 2010, and 2011, respectively, while the overall prevalence of obesity and abdominal obesity increased by 1.19-fold and 1.24-fold respectively in 2011 compared against 2001. In general, a gradual increase in the prevalence of severe obesity has been observed as years go by. Furthermore, trends of improvements in obesity awareness and management rates were visible over the period of surveys. CONCLUSION: Although the management status of obesity has improved during the recent years, more effective strategy to control obesity is needed.

Current Status of Diabetic Peripheral Neuropathy in Korea: Report of a Hospital-Based Study of Type 2 Diabetic Patients in Korea by the Diabetic Neuropathy Study Group of the Korean Diabetes Association

Diabetic peripheral neuropathy (DPN) is the most common complication associated with diabetes. DPN can present as a loss of sensation, may lead to neuropathic ulcers, and is a leading cause of amputation. Reported estimates of the prevalence of DPN vary due to differences in study populations and diagnostic criteria. Furthermore, the epidemiology and clinical characteristics of DPN in Korean patients with type 2 diabetes mellitus (T2DM) are not as well understood as those of other complications of diabetes such as retinal and renal disease. Recently, the Diabetic Neuropathy Study Group of the Korean Diabetes Association (KDA) conducted a study investigating the impact of DPN on disease burden and quality of life in patients with T2DM and has published some data that are representative of the nation. This review investigated the prevalence and associated clinical implications of DPN in Korean patients with diabetes based on the KDA study.

Prevalence of Diabetes and Prediabetes according to Fasting Plasma Glucose and HbA1c

BACKGROUND: Due to the inconvenience of performing oral glucose tolerance tests and day to day variability in glucose level, glycated hemoglobin (HbA1c) has been recommended by the American Diabetes Association as a method to diagnose diabetes. In addition, the Korean Diabetes Association has also recommended the use of HbA1c as a diagnostic test for diabetes. In this study, we evaluated the prevalence of diabetes according to fasting plasma glucose (FPG) level only or the combination of FPG and HbA1c tests. METHODS: Data from the 2011 Korea National Health and Nutrition Examination Survey (KNHANES) were analyzed. Among 5,811 subjects aged 30 years or older, 5,020 were selected after excluding the data of fasting time or =126 mg/dL, previous diagnosis of diabetes made by a medical doctor, current use of antidiabetic medications, and/or HbA1c > or =6.5%. Prediabetes was defined as FPG of 100 to 125 mg/dL and/or HbA1c of 5.7% to 6.4%. RESULTS: When we used FPG only, the prevalence of diabetes and prediabetes were 10.5% (men, 12.6%; women, 8.5%) and 19.3% (men, 23.8%; women, 14.9%), respectively. When HbA1c was included as a diagnostic test, the prevalence of diabetes and prediabetes increased to 12.4% (men, 14.5%; women, 10.4%) and 38.3% (men, 41%; women, 35.7%), respectively. Participants with HbA1c > or =6.5% and fasting glucose level <126 mg/dL were older and had lower estimated glomerular filtration rate. CONCLUSION: We concluded that using fasting glucose level only may result in an underestimation of diabetes and prediabetes. HbA1c is an acceptable complementary diagnostic test for diabetes in Korean patients. However, national standardization is needed to order to use HbA1c as a diagnostic method of diabetes and prediabetes.

Natural Course of Cytologically Benign Thyroid Nodules: Observation of Ultrasonographic Changes

BACKGROUND: The natural course of cytologically benign thyroid nodules remains unclear. The aim of this study was to evaluate whether ultrasonographic (US) changes are associated with changes in nodule volume during follow-up. METHODS: We retrospectively reviewed over 4 years of clinical records of patients with benign thyroid nodules as confirmed by fine needle aspiration (FNA). In total, 186 patients with 202 benign thyroid nodules were included for study. We assessed for changes in nodule volume and examined the cystic portion of the nodule as well as four US features (echogenicity, margin, calcification pattern, and shape). RESULTS: During follow-up (mean, 21.7+/-10.7 months) and using 50% as a cutoff value, nodule volumes increased in 11.8%, exhibited no change in 79.9%, and decreased in 8.3% of patients. Proportion of nodules demonstrating at least one US change was 20.8% (42/202). The most common US changes (in descending order of frequency) were cystic change, margin change, and calcification pattern change. Nodule shape and echogenicity rarely changed. Increased nodule volume was not significantly associated with any US features or with the number of FNAs but was associated with younger age at time of diagnosis. CONCLUSION: Although a portion of thyroid nodules confirmed as benign showed US changes or volume changes during the follow-up period, these findings may only represent the natural course of benign nodules. Frequent follow-up with US might be needed for only a small number of cases with suspicious US findings.

Prevalence of Diabetes and Prediabetes according to Fasting Plasma Glucose and HbA1c

BACKGROUND: Due to the inconvenience of performing oral glucose tolerance tests and day to day variability in glucose level, glycated hemoglobin (HbA1c) has been recommended by the American Diabetes Association as a method to diagnose diabetes. In addition, the Korean Diabetes Association has also recommended the use of HbA1c as a diagnostic test for diabetes. In this study, we evaluated the prevalence of diabetes according to fasting plasma glucose (FPG) level only or the combination of FPG and HbA1c tests. METHODS: Data from the 2011 Korea National Health and Nutrition Examination Survey (KNHANES) were analyzed. Among 5,811 subjects aged 30 years or older, 5,020 were selected after excluding the data of fasting time or =126 mg/dL, previous diagnosis of diabetes made by a medical doctor, current use of antidiabetic medications, and/or HbA1c > or =6.5%. Prediabetes was defined as FPG of 100 to 125 mg/dL and/or HbA1c of 5.7% to 6.4%. RESULTS: When we used FPG only, the prevalence of diabetes and prediabetes were 10.5% (men, 12.6%; women, 8.5%) and 19.3% (men, 23.8%; women, 14.9%), respectively. When HbA1c was included as a diagnostic test, the prevalence of diabetes and prediabetes increased to 12.4% (men, 14.5%; women, 10.4%) and 38.3% (men, 41%; women, 35.7%), respectively. Participants with HbA1c > or =6.5% and fasting glucose level <126 mg/dL were older and had lower estimated glomerular filtration rate. CONCLUSION: We concluded that using fasting glucose level only may result in an underestimation of diabetes and prediabetes. HbA1c is an acceptable complementary diagnostic test for diabetes in Korean patients. However, national standardization is needed to order to use HbA1c as a diagnostic method of diabetes and prediabetes.

Predictive Clinical Parameters and Glycemic Efficacy of Vildagliptin Treatment in Korean Subjects with Type 2 Diabetes

BACKGROUND: The aims of this study are to investigate the glycemic efficacy and predictive parameters of vildagliptin therapy in Korean subjects with type 2 diabetes. METHODS: In this retrospective study, we retrieved data for subjects who were on twice-daily 50 mg vildagliptin for at least 6 months, and classified the subjects into five treatment groups. In three of the groups, we added vildagliptin to their existing medication regimen; in the other two groups, we replaced one of their existing medications with vildagliptin. We then analyzed the changes in glucose parameters and clinical characteristics. RESULTS: Ultimately, 327 subjects were analyzed in this study. Vildagliptin significantly improved hemoglobin A1c (HbA1c) levels over 6 months. The changes in HbA1c levels (DeltaHbA1c) at month 6 were -2.24% (P=0.000), -0.77% (P=0.000), -0.80% (P=0.001), -0.61% (P=0.000), and -0.34% (P=0.025) for groups 1, 2, 3, 4, and 5, respectively, with significance. We also found significant decrements in fasting plasma glucose levels in groups 1, 2, 3, and 4 (P<0.05). Of the variables, initial HbA1c levels (P=0.032) and history of sulfonylurea use (P=0.026) were independently associated with responsiveness to vildagliptin treatment. CONCLUSION: Vildagliptin was effective when it was used in subjects with poor glycemic control. It controlled fasting plasma glucose levels as well as sulfonylurea treatment in Korean type 2 diabetic subjects.