Analysis of factors influencing pancreatic β-cell function in Japanese patients with type 2 diabetes: Association with body mass index and duration of diabetic exposure

• Published in: Diabetes research and clinical practice 2008-12, Vol.82 (3), p.353-358
• Main Authors: Funakoshi, Shogo, Fujimoto, Shimpei, Hamasaki, Akihiro, Fujiwara, Hideya, Fujita, Yoshihito, Ikeda, Kaori, Hamamoto, Yoshiyuki, Hosokawa, Masaya, Seino, Yutaka, Inagaki, Nobuya
• Format: Article
• Language: English
• Subjects: Asian Continental Ancestry Group; BMI; Body Mass Index; C-peptide; C-Peptide - blood; Cross-Sectional Studies; Diabetes Mellitus, Type 2 - diagnosis; Diabetes Mellitus, Type 2 - pathology; Disease duration; Endocrinology & Metabolism; Humans; Insulin - metabolism; Insulin Secretion; Insulin-Secreting Cells - metabolism; Insulin-Secreting Cells - physiology; Middle Aged; Regression Analysis; Time Factors; Type 2 diabetes; β-Cell
• ISSN: 0168-8227; 1872-8227
• DOI: 10.1016/j.diabres.2008.09.010

Abstract Aims To elucidate the clinical factors affecting β-cell function, serum C-peptide immunoreactivity (CPR) levels of patients with type 2 diabetes were analyzed. Methods Seven hundred Japanese patients with type 2 diabetes were enrolled. β-Cell function was evaluated by fasting CPR (FCPR), 6 min after intravenous injection of 1 mg glucagon (CPR-6 min), and the increment of CPR (ΔCPR). Simple regression analysis between FCPR, CPR-6 min, and ΔCPR and measures of variables and stepwise multiple regression analysis were carried out. Results Years from diagnosis and BMI were the major independent variables predicting β-cell function. Years from diagnosis was negatively correlated with CPR-6 min ( P < 0.0001, r = −0.271), and decrease in CPR-6 min was 0.050 ng/(ml year). BMI was positively correlated with CPR-6 min ( P < 0.0001, r = 0.369). When subjects were divided according to BMI, the decrease in CPR-6 min per year in the high-BMI group (0.068 ng/(ml year)) was greater than that in the low-BMI group (0.035 ng/(ml year)). Conclusion A linear decline in endogenous insulin secretion over more than several decades of diabetes was confirmed by this cross-sectional study. The duration of diabetes exposure and BMI are thus major factors in β-cell function in Japanese patients with type 2 diabetes.