Predictive Performance of Glycated Hemoglobin for Incident Diabetes Compared with Glucose Tolerance Test According to Central Obesity.

BACKGROUND: To examine whether glycated hemoglobin (HbA1c) test would be a suitable screening tool for detecting high-risk subjects for diabetes compared to oral glucose tolerance test (OGTT) according to accompanied central obesity. METHODS: In this prospective population-based cohort study, both OGTT and HbA1c tests were performed and continued every 2 years up to 12 years among individuals with non-diabetic state at baseline (aged 40 to 69 years, n=7,512). Incident diabetes was established by a doctor, HbA1c ≥6.5%, and/or fasting plasma glucose (FPG) ≥126 mg/dL, and/or 2-hour postprandial glucose (2hPG) level based on OGTT ≥200 mg/dL. Discriminative capacities of high HbA1c (≥5.7%) versus high 2hPG (≥140 mg/dL) for predicting incident diabetes were compared using Cox-proportional hazard regression and C-index. RESULTS: During the median 11.5 years of follow-up period, 1,341 (17.6%) developed diabetes corresponding to an incidence of 22.1 per 1,000 person-years. Isolated high 2hPG was associated with higher risk for incident diabetes (hazard ratio [HR], 4.29; 95% confidence interval [CI], 3.56 to 5.17) than isolated high HbA1c (HR, 2.79; 95% CI, 2.40 to 3.26; P<0.05). In addition, high 2hPG provided better discriminatory capacity than high HbA1c (C-index 0.79 vs. 0.75, P<0.05). Meanwhile, in subjects with central obesity, the HR (3.95 [95% CI, 3.01 to 5.18] vs. 2.82 [95% CI, 2.30 to 3.46]) and discriminatory capacity of incident diabetes (C-index 0.75 vs. 0.75) between two subgroups became comparable. CONCLUSION: Even though the overall inferior predictive capacity of HbA1c test than OGTT, HbA1c test might plays a complementary role in identifying high risk for diabetes especially in subjects with central obesity with increased sensitivity.

Simultaneous analysis of six major compounds in Osterici Radix and Notopterygii Rhizoma et Radix by HPLC and discrimination of their origins from chemical fingerprint analysis.

Osterici Radix, the dried roots of Ostericum koreanum Maximowicz, has long been used to treat cold, headache and arthralgia in Chinese medicine. Notopterygii Rhizoma et Radix, the dried rhizomes and roots of Notopterygium incisum Ting et H.T. Chang or Notopterygium forbesii Boiss (family: Umbelliferae), are well-known traditional Chinese medicines. These all herbal medicines were named kangwhoal in China, Japan and Korea. However no discrimination methods for the origin and no simultaneous analysis methods for bioactive components are currently available. We developed simultaneous analysis of six biomarkers including nodakenin (1), oxypeucedanin (2), bisabolangelone (3), notopterol (4), imperatorin (5), and isoimperatorin (6) using HPLC method. HPLC chromatographic separation was conducted with C18 column and mobile phase of acetonitrile (A) - water (B) (gradient, (A) 35%-65% (30 min)). The analytical condition was validated with specificity, selectivity, linearity (correlation coefficients of all bio marker were more than 0.999.), recovery (94.9-106.8%), precision and accuracy (intra and inter RSD < 2.99%). In addition, principal component analysis and cluster analysis was performed on analytical data of 38 commercial kangwhoal samples from different places. We confirmed to classify kangwhoal origins and this study was applied to quality evaluation and chemotaxonomy of medicinal herbs.