Identification of Impaired Second-Phase Insulin Secretion in Various Degrees of Glucose Tolerance in a Chinese Population.
Impaired insulin sensitivity and insulin secretion (ISEC) are major pathophysiologies of type 2 diabetes (T2DM). ISEC has two phases: the first and second phases (second ISEC). In this study, we derived equations to identify patients with second ISEC deficiency (ISEC-D).



Data from 96 patients, namely 19 with a normal fasting plasma glucose (FPG) level, 21 with prediabetes, and 56 with T2DM, were enrolled. They underwent a modified low-dose graded glucose infusion test, which was originally proposed by Polonsky et al. The test results were interpreted as the slopes of the changes of plasma insulin against the glucose levels, which were considered second ISEC. Patients with the lowest quartile of the slopes were defined as having ISEC-D. We built three models: Model 0: FPG, Model 1: FPG + waist circumference, and Model 2: Model 1 + fasting plasma insulin. The area under the receiver operating characteristic (aROC) curve was used to determine the predictive power of these models.



Among the metabolic syndrome components, FPG had the largest aROC curve (78.2%). Although aROC curves of Models 1 and 2 (85.2% and 91.5%, respectively) were higher than the aROC curve of FPG, no difference was observed between Models 1 and 0. By contrast, the aROC curve of Model 2 was higher compared with Model 1.



FPG showed the largest aROC curve. Model 2 had the highest predictive power, which could identify patients with ISEC-D with a sensitivity and specificity of 94.3% and 82.6%, respectively. These two models could be conveniently used in daily practice.
1 Division of Endocrinology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University , Taipei, Taiwan .|2 Division of Endocrinology and Metabolism, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University , Taipei, Taiwan .
Jiunn-Diann
JD
Lin
1 Division of Endocrinology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University , Taipei, Taiwan .|2 Division of Endocrinology and Metabolism, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University , Taipei, Taiwan .
Chung-Ze
CZ
Wu
3 Department of Internal Medicine, Cardinal Tien Hospital, Medical School, Catholic Fu Jen University , New Taipei City, Taiwan .
Dee
D
Pei
4 Division of Endocrinology and Metabolism, Department of Internal of Medicine, Buddhist Dalin Tzu Chi General Hospital and School of Medicine, Tzu Chi University , Hualien County, Taiwan .
Wei-Cheng
WC
Lian
5 Department of Family Medicine, Cardinal Tien Hospital, School of Medicine, Fu Jen Catholic University , New Taipei City, Taiwan .
Chun-Hsien
CH
Hsu
6 Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital , National Defense Medical School, Taipei City, Taiwan .
Chang-Hsun
CH
Hsieh
7 Department of Pathology, Cardinal Tien Hospital, School of Medicine, Fu Jen Catholic University , New Taipei City, Taiwan .
Yen-Lin
YL
Chen
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D005260:Female; D018149:Glucose Intolerance / Q000208:ethnology / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance / Q000502:physiology; D000078790:Insulin Secretion; D008297:Male; D024821:Metabolic Syndrome / Q000378:metabolism; D008875:Middle Aged; D011236:Prediabetic State / Q000378:metabolism*
D001786:Blood Glucose; D007328:Insulin