Association of abdominal fat distribution and cardiometabolic risk factors among obese Korean adolescents

The association between abdominal fat distribution and cardiometabolic risk factors using direct measures of abdominal fat in adolescents has not been extensively researched. This study was designed to investigate the association between visceral and subcutaneous fat and cardiometabolic risk factors, in obese Korean adolescents. The study enrolled 175 adolescents (72 boys, 103 girls), from ages nine to 19 years, who were referred to the Obesity Clinic of Asan Medical Center. Body mass index (BMI) and waist circumference (WC) were measured for each study participant. Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) areas were calculated by computed tomography. Blood pressure, fasting plasma glucose, total cholesterol, triglycerides, HDL cholesterol, insulin and homeostasis model assessment (HOMA) score were measured. Systolic blood pressure, HDL cholesterol, fasting insulin and the HOMA score were significantly correlated with BMI, WC, VAT and SAT. In addition, VAT was significantly correlated with diastolic blood pressure and triglyceride levels. On multiple regression analysis, VAT was independently correlated with blood pressure, triglycerides, HDL cholesterol, fasting insulin and the HOMA score, while SAT was independently correlated with systolic blood pressure, fasting insulin and the HOMA score. This study determined that cardiovascular risk factors are closely associated with VAT, while insulin resistance is closely associated with both VAT and SAT among obese Korean adolescents.     

男性2型糖尿病患者胰岛素抵抗与前列腺特异性抗原的相关性研究

目的探讨在男性2型糖尿病患者中胰岛素抵抗与前列腺特异性抗原（prostate specific antigen,PSA）的相关性。方法男性2型糖尿病183例,检测空腹血糖（FPG）、空腹胰岛素（FINS）、糖化血红蛋白（HbA1C）、血脂系列（TC、TG、LDL、HDL）、游离前列腺特异性抗原（fPSA）和总前列腺特异性抗原（tPSA）浓度等相关临床指标,计算胰岛素抵抗指数（HOMAIR）、体质指数（BMI）。根据HOMA-IR分为胰岛素抵抗组（IR≥2.8）和非胰岛素抵抗组（IR〈2.8）;根据tPSA的中位数0.732μg/L,将患者分为tPSA≥0.732μg/L组和tPSA〈0.732μg/L组。结果胰岛素抵抗组（69例）患者的BMI明显高于非胰岛素抵抗组（114例）（P〈0.05）,tPSA明显低于非胰岛素抵抗组（P〈0.05）。tPSA≥0.732μg/L组（92例）的BMI、HOMA-IR均低于tPSA〈0.732μg/L组（91例）（均P〈0.05）。tPSA与年龄、fPSA、LDL呈正相关（r分别为0.345、0.865、0.200;均P〈0.05）,与IR、BMI呈负相关（r分别为-0.151、-0.155;均P〈0.05）。结论胰岛素抵抗和肥胖是导致PSA下降的因素。     

Prevalence and progression of carbohydrate disorders in patients with pheochromocytoma/paraganglioma: retrospective single-center study

BackgroundCarbohydrate disorders are the most frequent metabolic disorders, affecting a significant proportion of patients with pheochromocytoma.ObjectiveA retrospective study assessed the prevalence and progression of carbohydrate disorders in 204 patients (92 men, 112 women) with histologically proven pheochromocytoma diagnosed in a single specialized tertiary center during a 40-year period (1978–2017). One hundred were followed-up after tumor removal.ResultsCarbohydrate disorders were diagnosed in 49.5% of cases: 30.4% with diabetes and, 19.1% prediabetes. Subjects with carbohydrate disorders had significantly greater age at diagnosis and higher 24-hour urine metanephrine and normetanephrine concentrations than those with normal glucose tolerance. One-third of patients with diabetes achieved good glycemic control under oral treatment (54% on metformin monotherapy). One-third of patients overall required preoperative insulin treatment. Postoperative follow-up (100 patients; 5-year mean duration) showed reduced prevalence of diabetes (13% vs. 33%; P = 0.0007) and prediabetes (12% vs. 24%; P = 0.027). Almost 60% of subjects initially diagnosed with carbohydrate disorders recovered normal glucose tolerance after surgery; these subjects had significantly higher preoperative urine metanephrine/normetanephrine levels than those with persistent diabetes/prediabetes. Correlation analysis revealed a moderate negative relationship between urine metanephrine/normetanephrine concentration and the outcome of the carbohydrate disorders (Spearmen's Rho = − 0.507; P = 0.013). There was no significant difference according to pre- or postoperative prevalence of obesity (15% vs. 16%; P = 0.845) or dyslipidemia (46% vs. 39%; P = 0.316).ConclusionsCarbohydrate disorders affect approximately 50% of pheochromocytoma patients; 30% develop overt diabetes, which may be the only clinical manifestation in some rare cases. Pheochromocytoma-related diabetes is more likely to affect patients with predominant adrenaline secretion. It is often easy to control and usually requires oral antidiabetic treatment. Reversibility of carbohydrate disorders depend on severity, preoperative metanephrine level, age and weight.     

HOMA or QUICKI: is it useful to test the reproducibility of formulas?

AIM: HOMA and QUICKI are the most widely used indices for assessing insulin sensitivity. Both are based on fasting glucose and insulin measures, and mainly differ by the log transformation of these variables in QUICKI. However, HOMA is less reproducible than QUICKI, and log HOMA does not improve its reproducibility. The aim of this study was to investigate the various mathematical transformations of HOMA and to assess its reproducibility. METHOD: We used data from a clamp study involving 123 non-diabetic overweight and obese postmenopausal women. Fasting insulin and glucose were measured in two visits 15 and 30 days apart. This allowed us to calculate HOMA as (fasting glucose [mmol/L] x fasting insulin [microU/mL])/22.5 and QUICKI as 1/(log fasting glucose [mg/dL]+log fasting insulin [microU/mL]) twice for subjects who were weight-stable between visits. RESULTS: QUICKI had better reproducibility (CV=3.9%) than either HOMA (CV=26.7%) or log HOMA (CV=22.0%). However, log-transforming HOMA using log (glucose x insulin)/log (22.5) and log-transforming HOMA without transforming the constant denominator improved its CV to 6.5% and 5.7%, respectively. CONCLUSION: By modifying the mathematical expression of HOMA, we were able to achieve comparable CVs for QUICKI and HOMA. However, the CV should be used to assess the reproducibility of techniques to measure glucose and insulin, not of mathematical formulas. When evaluating indices for the assessment of insulin sensitivity, the key point is how well they correlate with the 'gold-standard' glucose clamp.