Kyeong Seon Park

Comparison between two methods of bioelectrical impedance analyses for accuracy in measuring abdominal visceral fat area

OBJECTIVES To compare the accuracy of abdominal visceral fat area (VFA) measurements between abdominal dual bioelectrical impedance analysis (BIA) and whole-body BIA referenced to computed tomography (CT) measures. METHODS Abdominal VFAs were measured in 102 individuals: 59 men and 43 women with a mean age of 44.2 ± 16.3 years (range 21 - 76), body mass index 23.9 ± 7.8 kg/m(2) (range 18 - 35) using a DUALSCAN HDS-2000 machine (dual abdominal BIA) and an InBody720 machine (whole-body BIA). The VFA values from each machine were compared with those from CT under various conditions. RESULTS Mean abdominal VFAs were 116 ± 69 cm(2) by CT, 89 ± 47 cm(2) by dual abdominal BIA, and 84 ± 33 cm(2) by whole-body BIA. The former measure showed a higher correlation with the CT measure than the latter (r=0.89 vs. r=0.64, P<0.001). Both BIA methods tended to underestimate abdominal VFAs compared with CT scans when CT VFA was not small. The dual abdominal BIA had less bias than the whole-body BIA in the assessment of VFAs. The whole-body BIA was affected by subcutaneous fat area. CONCLUSIONS Dual BIA was more accurate in assessing abdominal VFA than whole-body BIA.

Clinical Characteristics of the Responders to Dipeptidyl Peptidase-4 Inhibitors in Korean Subjects with Type 2 Diabetes

We investigated characteristics associated with the efficacy of dipeptidyl peptidase-4 inhibitors (DPP4i) in Korean patients with type 2 diabetes. We reviewed medical records of 477 patients who had taken sitagliptin or vildagliptin longer than 40 weeks. Response to DPP4i was evaluated with HbA1c change after therapy (ΔHbA1c). The Students t-test between good responders (GR: ΔHbA1c > 1.0%) and poor responders (PR: ΔHbA1c < 0.5%), a correlation analysis among clinical parameters, and a linear multivariate regression analysis were performed. The mean age was 60 yr, duration of diabetes 11 yr and HbA1c was 8.1%. Baseline fasting plasma glucose (FPG), HbA1c, C-peptide, and creatinine were significantly higher in the GR compared to the PR. Duration of diabetes, FPG, HbA1c, C-peptide and creatinine were significantly correlated with ΔHbA1c. In the multivariate analysis, age (r2 = 0.006), duration of diabetes (r2 = 0.019), HbA1c (r2 = 0.296), and creatinine levels (r2 = 0.024) were independent predictors for the response to DPP4i. Body mass index and insulin resistance were not associated with the response to DPP4i. In conclusion, better response to DPP4i would be expected in Korean patients with type 2 diabetes who have higher baseline HbA1c and creatinine levels with shorter duration of diabetes.

Characterization of Patients with Type 2 Diabetes according to Body Mass Index: Korea National Health and Nutrition Examination Survey from 2007 to 2011

Background The present study aimed to investigate the clinical characteristics of type 2 diabetes mellitus (T2DM) in Korean adults according to body mass index (BMI) and to analyze the association with cardiovascular disease (CVD). Methods We conducted a cross-sectional study of data from the Korea National Health and Nutrition Examination Survey from 2007 to 2011. A total of 3,370 patients with T2DM were divided into categories according to BMI. We conducted a comparison of the T2DM patient population composition by BMI category between different countries. We investigated the prevalence of awareness, treatment, and target control of T2DM according to BMI. Results Patients with T2DM had a higher BMI, and were more likely to have a history of CVD than healthy controls. For Korean adults with T2DM, 8% had BMI ≥30 kg/m2. By contrast, the population of patients with T2DM and BMI ≥30 kg/m2 was 72% in patients in the USA and 56% in the UK. The rate of recognition, treatment, and control has worsened in parallel with increasing BMI. Even in patients with BMI 25 to 29.9 kg/m2, the prevalence of CVD or high risk factors for CVD was significantly higher than in patients with BMI 18.5 to 22.9 kg/m2 (odds ratio, 2.07). Conclusion Korean patients with T2DM had lower BMI than those in Western countries. Higher BMI was associated with lower awareness, treatment, and control of diabetes, and a positive association was observed between CVD or high risk factors for CVD and BMI, even for patients who were overweight but not obese.

Diagnostic Role of Captopril Challenge Test in Korean Subjects with High Aldosterone-to-Renin Ratios.

Background Diagnosis of primary aldosteronism (PA) begins with aldosterone-to-renin ratio (ARR) measurement followed by confirmative tests. However, the ARR has high false positive rates which led to unnecessary confirmatory tests. Captopril challenge test (CCT) has been used as one of confirmatory tests, but the accuracy of it in the diagnosis of PA is still controversial. We aimed to examine the clinical efficacy of CCT as a post-screening test in PA. Methods In a prospective study, we enrolled subjects with suspected PA who had hypertension and ARR >20 (ng/dL)/(ng/mL/hr). Sixty-four patients who underwent both the saline infusion test and the CCT were included. Results The diagnostic performance of plasma aldosterone concentration (PAC) post-CCT was greater than that of ARR post-CCT and ARR pre-CCT in PA (area under the curve=0.956, 0.797, and 0.748, respectively; P=0.001). A cut-off value of 13 ng/dL showed the highest diagnostic odds ratio considering PAC post-CCT at 60 and 90 minutes. A PAC post-CCT of 19 ng/dL had a specificity of 100%, which can be used as a cut-off value for the confirmative test. Determining the diagnostic performance of PAC post-CCT at 90 minutes was sufficient for PA diagnosis. Subjects with PAC post-CCT at 90 minutes <13 ng/dL are less likely to have PA, and those with PAC post-CCT at 90 minutes ≥13 but <19 ng/dL should undergo secondary confirmatory tests. Conclusion The CCT test may be a reliable post-screening test to avoid the hospitalization in the setting of falsely elevated ARR screening tests.

Optimal follow-up strategies for adrenal incidentalomas: reappraisal of the 2016 ESE-ENSAT guidelines in real clinical practice

OBJECTIVE Recently, the European Society of Endocrinology (ESE), in collaboration with the European Network for the Study of Adrenal Tumors (ENSAT), asserted that adrenal incidentalomas (AIs) <4 cm and ≤10 Hounsfield units (HU) do not require further follow-up imaging. To validate the clinical application of the follow-up strategies suggested by the 2016 ESE-ENSAT guidelines, we explored the clinical characteristics and natural course of AIs in a single center over 13 years. DESIGN AND METHODS This retrospective cohort study included a total of 1149 patients diagnosed with AIs between 2000 and 2013 in a single tertiary center. Hormonal examination and radiological evaluations were performed at the initial diagnosis of AI and during the follow-up according to the appropriate guidelines. RESULTS The mean age at diagnosis was 54.2 years, and the majority of AIs (68.0%) were nonfunctional lesions. Receiver operating curve analysis was used to discriminate malignant from benign lesions; the optimal cut-off value for mass size was 3.4 cm (sensitivity: 100%; specificity: 95.0%), and that for the pre-contrast HU was 19.9 (sensitivity: 100%; specificity: 67.4%). The majority of nonfunctional lesions did not change in size during the 4-year follow-up period. Applying a cut-off value of 1.8 μg/dL after a 1-mg overnight dexamethasone suppression test, 28.0% of all nonfunctional AIs progressed to autonomous cortisol secretion during the follow-up period. However, we observed no development of overt Cushings syndrome in the study. CONCLUSIONS We advocate that no follow-up imaging is required if the detected adrenal mass is <4 cm and has clear benign features. However, prospective studies with longer follow-up are needed to confirm the appropriate follow-up strategies.

Efficacy of a New Medical Information system, Ubiquitous Healthcare Service with Voice Inception Technique in Elderly Diabetic Patients

We have demonstrated previously that an individualized health management system using advanced medical information technology, named ubiquitous (u)-healthcare, was helpful in achieving better glycemic control than routine care. Recently, we generated a new u-healthcare system using a voice inception technique for elderly diabetic patients to communicate information about their glucose control, physical activity, and diet more easily. In a randomized clinical trial, 70 diabetic patients aged 60–85 years were assigned randomly to a standard care group or u-healthcare group for 6 months. The primary end points were the changes in glycated hemoglobin (HbA1c) and glucose fluctuation assessed by the mean amplitude glycemic excursion (MAGE). Changes in body weight, lifestyle, and knowledge about diabetes were also investigated. After 6 months, the HbA1c levels decreased significantly in the u-healthcare group (from 8.6 ± 1.0% to 7.5 ± 0.6%) compared with the standard care group (from 8.7 ± 0.9% to 8.2 ± 1.1%, P < 0.01). The MAGE decreased more in the u-healthcare group than in the standard care group. Systolic blood pressure and body weight decreased and liver functions improved in the u-healthcare group, but not in the standard care group. The u-healthcare system with voice inception technique was effective in achieving glycemic control without hypoglycemia in elderly diabetic patients (Clinicaltrials.gov: NCT01891474).

Comparison of Abdominal Visceral Adipose Tissue Area Measured by Computed Tomography with That Estimated by Bioelectrical Impedance Analysis Method in Korean Subjects.

We evaluated the concordance between visceral fat area (VFA) estimated by bioelectrical impedance analysis (BIA) or computed tomography (CT) in Korean subjects with a wide range in age and body mass index (BMI). In 1006 individuals (mean age 55.2 ± 11.8 (19–87) years, mean BMI 26.0 ± 3.5 (17–46) kg/m2, 48.9% men), VFA quantified by CT was compared with VFA using multifrequency BIA machines within 15 days. Concordance rates were compared by age or BMI using correlation analysis, Bland-Altman plots, and intraclass correlation coefficient (ICC). Using BIA data, we established a regression formula to reflect CT-VFA. The mean VFAs by CT and BIA were 131.9 ± 57.3 cm2 and 110.5 ± 33.9 cm2, respectively (r = 0.605, p < 0.001). The mean difference was 21.4 ± 45.6 cm2, tending to increase with BMI. In women with BMI <25 kg/m2 or age <50 years, the VFAs by BIA were similar to those by CT (ICC = 0.496 in BMI <25 kg/m2 and ICC = 0.638 in age <50 years). However, the difference was greater in men with BMI ≥25 kg/m2 or age ≥50 years. Applying our formula, the difference between estimations decreased to 0.2 ± 38.2cm2. VFA estimated by BIA correlated well with that by CT, but a more accurate formula is needed to match CT data, particularly in older men or subjects with a high BMI.

Comparison of pancreatic volume and fat amount linked with glucose homeostasis between healthy Caucasians and Koreans

To compare pancreatic volume and fat amount, and their associations with glucose homeostasis, in a Korean and a white population.

Clinical Characteristics and Metabolic Predictors of Rapid Responders to Dipeptidyl Peptidase-4 Inhibitor as an Add-on Therapy to Sulfonylurea and Metformin

Background Dipeptidyl peptidase-4 (DPP-4) inhibitor add-on therapy is a new option for patients with inadequately controlled type 2 diabetes who are taking combined metformin and sulfonylurea (SU). We evaluated the efficacy and safety of this triple therapy and the characteristics of rapid responders and hypoglycemia-prone patients. Methods We included 807 patients with type 2 diabetes who were prescribed a newly added DPP-4 inhibitor to ongoing metformin and SU in 2009 to 2011. Glycemia and other metabolic parameters at baseline, 12, 24, and 52 weeks, as well as episodes of hypoglycemia were analyzed. Rapid responders were defined as patients with ≥25% reduction in glycosylated hemoglobin (HbA1c) within 12 weeks. Results At baseline, while on the submaximal metformin and SU combination, the mean HbA1c level was 8.4%. Twelve weeks after initiation of DPP-4 inhibitor add-on, 269 patients (34.4%) achieved an HbA1c level ≤7%. Sixty-six patients (8.2%, 47 men) were rapid responders. The duration of diabetes was shorter in rapid responders, and their baseline fasting plasma glucose (FPG), HbA1c, C-peptide, and homeostasis model assessment of insulin resistance were significantly higher. Patients who experienced hypoglycemia after taking DPP-4 inhibitor add-on were more likely to be female, to have a lower body weight and lower triglyceride and FPG levels, and to have higher homeostasis model assessment of β-cells. Conclusion An oral hypoglycemic triple agent combination including a DPP-4 inhibitor was effective in patients with uncontrolled diabetes. Proactive dose reduction of SU should be considered when a DPP-4 inhibitor is added for rapid responders and hypoglycemia-prone patients.

Outcomes analysis of surgical and medical treatments for patients with primary aldosteronism

Patients with aldosterone-producing adenomas are treated using surgery, and patients with idiopathic hyperaldosteronism receive medical treatment using mineralocorticoid receptor antagonists (MRAs). However, the outcomes of surgical and medical treatment for primary aldosteronism (PA) remain unclear. Therefore, we compared the outcomes of surgical and medical treatment for PA and aimed to identify a specific subgroup that might benefit from medical treatment. We identified 269 patients who were treated for PA (unilateral excess: 221 cases; bilateral excess: 48 cases) during 2000-2015 at the Seoul National University Hospital and two other tertiary centers. The main outcomes were the amelioration of hypertension and hypokalemia. Treatment improved hypertension in the surgical treatment group (78.2%) and the medical treatment group (55.6%) (p = 0.001). At the last follow-up, hypokalemia was normalized in the surgical treatment group (97.1%) and the medical treatment group (93.7%, p = 0.046). Among patients with unilateral aldosterone excess, surgery provided advantages in resolving hypertension without worsening renal function. Among patients who were >60 years old or had impaired renal function, surgical and medical treatment provided similar amelioration of hypokalemia and hypertension. Three patients developed hyperkalemia after surgery, and no patients developed hyperkalemia after initiating medical treatment. The surgical treatment group exhibited a lower postoperative estimated glomerular filtration rate (eGFR) and higher serum potassium levels, compared to the medical treatment group. Surgical treatment provided better hypertension and hypokalemia outcomes among patients with PA, compared to medical treatment. However, MRAs may be appropriate for elderly patients with impaired renal function.