Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 57 3 2019 05 13 160 166 EN Saeed Nazari Soltan Ahmad Department of Biochemistry, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran. Sajjad Nourollahi Department of Laboratory Medicine, School of Paramedical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Manouchehr Nakhjavani Endocrinology and Metabolism Research Center, Vali-Asr Hospital, Tehran University of Medical Sciences, Tehran, Iran. Mehran Khojastehfard Department of Biochemistry, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran Mostafa Mostafazadeh Department of Biochemistry, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran. Hamed Hajipour Department of Reproductive Biology, School of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran. Davoud Sanajou Department of Biochemistry, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran. 2018 05 10 2019 01 02 The relation between serum preptin, myostatin, insulin, and also homeostatic model assessment-insulin resistance were examined in pre-diabetes 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), pre-diabetes (group 2=30), and T2DM (group 3=29). Serum insulin, preptin, and myostatin levels were measured with immunoradiometric assay (IRMA), enzyme-linked immunosorbent assay (ELISA), and chemiluminescent immunoassay (CLIA), respectively. Patients with T2DM had higher levels of preptin compared to normoglycemic (461.25±53.90 vs. 407.54±54.78, P<0.001). Furthermore, these patients had elevated levels of myostatin compared with controls (2710.60±559.09 vs. 2246.37±416.40, P<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 pre-diabetic subjects and even further in type 2 diabetic patients. The correlation between preptin and insulin evolves when pre-diabetes or overt type 2 diabetes develops. Moreover, serum myostatin increases in association with insulin and not HOMA-IR in diabetic conditions. https://acta.tums.ac.ir/index.php/acta/article/view/7250 https://acta.tums.ac.ir/index.php/acta/article/download/7250/5231