title: Relationship of Hemoglobin A1c with β Cell Function and Insulin Resistance in Newly Diagnosed and Drug Naive Type 2 Diabetes Patients.
abstract: OBJECTIVE
  To investigate changes in the glycated hemoglobin A1c (A1c) level and those in β cell function and insulin resistance in newly diagnosed and drug naive type 2 diabetes patients and to evaluate the relationship between them.
  
  
  METHODS
  A total of 818 newly diagnosed diabetic individuals who were ≥ 40 years of age were recruited. The subjects were grouped by A1c values (<6.5%, 6.5-7%, 7-8%, 8-9%, and ≥ 9%). The homeostasis model assessment (HOMA) was used to evaluate pancreatic β cell function (HOMA-β) and insulin resistance (HOMA-IR). ANOVA, t-tests, and binary logistic regression analysis were used for data analysis.
  
  
  RESULTS
  Compared with subjects with A1c values <6.5%, individuals with an A1c of 6.5-7% exhibited an increased HOMA-β index. However, the HOMA-β index was significantly decreased at A1c values ≥ 7% and further decreased by 9.3% and by 23.7%, respectively, at A1c values of 7-8% and 8-9%. As A1c increased to ≥ 9%, a 62% reduction in β cell function was observed, independently of age, gender, body mass index (BMI), blood pressure (BP), blood lipids, and hepatic enzyme levels. Meanwhile, insulin resistance was significantly increased with an increase in A1c values.
  
  
  CONCLUSIONS
  Elevated A1c values (≥ 7%) were associated with substantial reductions in β cell function.
authors.affiliation: Department of Endocrinology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China.
authors.forename: Xinguo
authors.initials: X
authors.lastname: Hou
authors.affiliation: Department of Endocrinology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China.
authors.forename: Jinbo
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Endocrinology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Song
authors.affiliation: Department of Endocrinology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China.
authors.forename: Chuan
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Endocrinology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Liang
authors.affiliation: Department of Endocrinology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Sun
authors.affiliation: China National Heavy Duty Truck Group Corporation Hospital, Jinan, Shandong 250116, China.
authors.forename: Zeqiang
authors.initials: Z
authors.lastname: Ma
authors.affiliation: Lukang Hospital of Jining, Jining, Shandong 272141, China.
authors.forename: Weifang
authors.initials: W
authors.lastname: Yang
authors.affiliation: Department of Endocrinology, Second People's Hospital of Jining, Jining, Shandong 272049, China.
authors.forename: Chengqiao
authors.initials: C
authors.lastname: Li
authors.affiliation: Shantui Community Health Center, Jining, Shandong 272000, China.
authors.forename: Xiuping
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Endocrinology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Lin
authors.affiliation: Department of Endocrinology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Gong
authors.affiliation: Department of Endocrinology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China.
authors.forename: Meijian
authors.initials: M
authors.lastname: Wang
authors.affiliation: Department of Endocrinology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China.
authors.forename: Fuqiang
authors.initials: F
authors.lastname: Liu
authors.affiliation: Department of Endocrinology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China.
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Endocrinology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Yan
authors.affiliation: Department of Endocrinology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Qin
authors.affiliation: Department of Endocrinology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China.
authors.forename: Lingshu
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Endocrinology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China.
authors.forename: Jidong
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Endocrinology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China.
authors.forename: Ruxing
authors.initials: R
authors.lastname: Zhao
authors.affiliation: Department of Endocrinology, The Second Hospital of Shandong University, Jinan, Shandong 250012, China.
authors.forename: Shihong
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Endocrinology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China.
authors.forename: Li
authors.initials: L
authors.lastname: Chen
mesh_terms: D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000502:physiology; D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000378:metabolism*; D005260:Female; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D007328:Insulin / Q000097:blood*; D007333:Insulin Resistance / Q000502:physiology*; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007328:Insulin; D008055:Lipids