Adiponectin Appears to Have Different Mechanisms in Type 1 and Type 2 Diabetes with C-peptide as an Important Link

Adiponectin (ApN) is considered to be responsible for reduction of inflammation and is known to be included in lipid metabolism. This study was designed to assess the role of adiponectin in patients with type 1 and type 2 diabetes and to determine parameters important in the prediction of adiponectin. Adiponectin, high sensitive C-reactive protein, fibrinogen, homocysteine, C-peptide, and lipid panel in addition to clinical and laboratory parameters important for the definition of diabetes, obesity and the metabolic syndrome were measured in 118 patients included in the study. The best model (R2=0.989) for predicting adiponectin in type 1 diabetes included fibrinogen, white blood cell count, uric acid and triglycerides. In type 2 diabetes the best model (R2=0.751) included C-peptide, white blood cell count, systolic blood pressure, fasting blood glucose, glycated hemoglobin and high-density lipoprotein cholesterol. ANOVA showed statistically significant among-group differences in adiponectin (p=0.028), body mass index (p<0.001), fasting blood glucose (p<0.001) and high-density lipoprotein cholesterol (p=0.012) according to the type of diabetes. Significant between-group differences were also observed in adiponectin (p=0.033) and high-density lipoprotein cholesterol (p=0.009) according to sex. Adiponectin correlated significantly (p<0.05) with body mass index, C-peptide, pulse pressure and high-density lipoprotein cholesterol. Adiponectin levels were significantly higher in type 1 diabetes. The association between C-peptide and adiponectin is probably one of the reasons for their different respective levels in different types of diabetes. Interrelations between adiponectin and inflammation, dyslipidemia, C-peptide levels and sex appear to be important for complex adiponectin modulation and action.