Anemia Is Inversely Associated with Serum C-Peptide Concentrations in Patients with Type 2 Diabetes

Results: The aim of the study was to investigate the relationship between anemia and serum C-peptide concentrations in Korean patients with type 2 diabetes. A total of 1,300 subjects with type 2 diabetes were investigated in this cross-sectional study. Fasting C-peptide concentration, 2-hour postprandial C-peptide concentration, and δC-peptide (postprandial C-peptide minus fasting C-peptide) concentration were measured in all patients. Anemia was defined according to the World Health Organization. Fasting C-peptide level, postprandial C-peptide level, and δC-peptide level was lesser in subjects with anemia. According to the grade of anemia, the average C-peptide levels were significantly different after adjusting for other covariates (fasting C-peptide level: no anemia, 0.73 mmol/l; grade I anemia, 0.66 mmol/l; grade II anemia, 0.62 mmol/l; P for trend = 0.002; postprandial C-peptide level: no anemia, 1.54 mmol/l; grade I anemia, 1.36 mmol/l; grade II anemia, 1.32 mmol/l; P for trend < 0.001; δC-peptide level: no anemia, 0.75 mmol/l; grade I anemia, 0.64 mmol/l; grade II anemia, 0.60 mmol/l; P for trend = 0.001). In the multivariate model, the association between anemia and serum C-peptide concentrations remained significant, after adjustment for confounding factors including age, gender, familial diabetes, body mass index, duration of diabetes, glycated hemoglobin, free fatty acid, hypertension, and hyperlipidemia (fasting C-peptide level: β= -0.057, P =0.032; postprandial C-peptide level: β= -0.098, P <0.001; δC-peptide level: β= -0.095, P <0.001, respectively). Our results showed that anemia was inversely associated with serum C-peptide concentrations in subjects with type 2 diabetes.