title: Decreased beta cell function and insulin sensitivity contributed to increasing fasting glucose in Chinese.
abstract: To evaluate the role of insulin resistance and beta cell function to increasing fasting plasma glucose (FPG), 1,272 Chinese subjects (18-80 years of age) were divided into normal glucose tolerance (NGT), impaired fasting glucose (IFG), impaired glucose tolerance (IGT), combined glucose intolerance (CGI), and type 2 diabetes mellitus (T2DM) according to oral glucose tolerance test. Insulin sensitivity was measured by Matsuda index (ISI(M)) and homeostasis model assessment of insulin resistance (1/HOMA-IR); β-cell function adjusted by insulin sensitivity was assessed from disposition index (DI) at basal DI(0) (homeostasis model assessment of β-cell function (HOMA-B) × [1/HOMA-IR]), early-phase DI(30) (the ratio of total insulin AUC and total glucose AUC during 0-30 min of the OGTT (InsAUC(30)/GluAUC(30)) × ISI(M)) and total DI(120) (the ratio of total insulin AUC and total glucose AUC during 0-120 min of the OGTT (InsAUC(120)/GluAUC(120)) × ISI(M)). Compared with NGT, in IFG, ISI(M) (-23%), DI(0) (-38%), DI(30) (-30%), and DI(120) (-31%) were decreased significantly. As the FPG increased across categories classified by FPG levels from NGT → IFG → T2DM with 2 h PG < 7.8 mmol/l, ISI(M), DI(0), DI(30) and DI(120) showed decline beginning from normal range of FPG, compared with the reference category of FPG < 4.0 mmol/l. Correlation analysis showed that ISI(M) and DI were correlated inversely with FPG concentration (r = -0.242 for ISI(M), r = -0.933 for DI(0), r = -0.806 for DI(30), r = -0.817 for DI(120); P < 0.001). Both the impairment of beta cell function and insulin sensitivity started at the low point of FPG within the normoglycemic range and contributed to the deterioration of fasting glucose.
authors.affiliation: Department of Endocrinology, Drum Tower Hospital Affiliated to Nanjing University Medical School, Zhongshan Road 321, 210008 Nanjing, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Bi
authors.forename: Dalong
authors.initials: D
authors.lastname: Zhu
authors.forename: Yali
authors.initials: Y
authors.lastname: Jing
authors.forename: Yun
authors.initials: Y
authors.lastname: Hu
authors.forename: Wenhuan
authors.initials: W
authors.lastname: Feng
authors.forename: Shanmei
authors.initials: S
authors.lastname: Shen
authors.forename: Guoyu
authors.initials: G
authors.lastname: Tong
authors.forename: Xujun
authors.initials: X
authors.lastname: Shen
authors.forename: Tingting
authors.initials: T
authors.lastname: Yu
authors.forename: Dan
authors.initials: D
authors.lastname: Song
authors.forename: Donghui
authors.initials: D
authors.lastname: Yang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001786:Blood Glucose / Q000378:metabolism; D002681:China; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D015536:Down-Regulation; D005215:Fasting; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007333:Insulin Resistance; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D001786:Blood Glucose