Preptin and Myostatin Independently Increase in PreDiabetics and Patients of Type 2 Diabetes Mellitus

The relation between serum preptin, myostatin, insulin, and also homeostatic model assessmentinsulin resistance were examined in prediabetes persons and newly diagnosed patients with overt type 2 diabetes mellitus. A total of 84 subjects were included in the study and assigned into three groups: normoglycemic participants (group 1=27), prediabetes (group 2=30), and T2DM (group 3=29). Serum insulin, preptin, and myostatin levels were measured with immunoradiometric assay (IRMA), enzymelinked immunosorbent assay (ELISA), and chemiluminescent immunoassay (CLIA), respectively. Patients with T2DM had higher levels of preptin compared to normoglycemic (461.25 #xB1;53.90 vs. 407.54 #xB1;54.78, P lt;0.001). Furthermore, these patients had elevated levels of myostatin compared with controls (2710.60 #xB1;559.09 vs. 2246.37 #xB1;416.40, P lt;0.001). Preptin and myostatin both positively correlated with serum insulin (r=0.369, P=0.01, and r=0.309, P=0.04, respectively). However, no significant association was found between serum preptin and myostatin levels. Stepwise multiple regression analysis showed that insulin was affected more by preptin, with only a trivial contribution from myostatin. Serum preptin and myostatin levels increase in prediabetic subjects and even further in type 2 diabetic patients. The correlation between preptin and insulin evolves when prediabetes or overt type 2 diabetes develops. Moreover, serum myostatin increases in association with insulin and not HOMAIR in diabetic conditions.