262 JKMU Journal of Kerman University of Medical Sciences, 2020; 27 (3): 262-269 Circulating Levels of C1q/TNF-Related Protein-12 (CTRP-12) in Patients with Type 2 Diabetes: A Case-control Study Sattar Gorgani-Firuzjaee, Ph.D. 1 , Hadi Khodabandehloo, Ph.D. 2 1- Assistant Professor, Department of Medical Laboratory Sciences, School of Allied Health Medicine, AJA University of Medical sciences, Tehran, Iran 2- Assistant Professor, Department of Clinical Biochemistry, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran (Corresponding author; E-mail: h.khodabandehloo@zums.ac.ir) Received: 10 October, 2019 Accepted: 2 May, 2020 ARTICLE INFO Article type: Original Article Keywords: Type 2 diabetes CTRP-12 Adipolin Abstract Background: The C1q complement/TNF-related protein (CTRP) superfamily is a newly diagnosed adipokine with anti-inflammatory, insulin sensitivity, and glucose lowering effects. This study aimed to assess the plasma circulating levels of CTRP12 in type 2 diabetic (T2D) patients and healthy subjects. Methods: In this case-control study, plasma concentration of CTRP12 was measured by ELISA in 60 subjects (30 T2D and 30 healthy participants). The systolic blood pressure (SBP), waist circumference (WC), waist-to-hip ratio (WHR), body mass index (BMI), fasting blood sugar (FBS), glycated hemoglobin (HbA1c), insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) were measured. Results: In contrast to the SBP, WC, WHR, BMI, FBS, HbA1c, insulin, and HOMA-IR, the levels of CTRP12 were significantly lower in T2D patients. There was significant negative correlation between CTRP12, FBS, and HbA1c. The regression analysis showed that when subjected to stepwise multiple regression analysis, HbA1c (β = -2.21; P < 0.004) was predictive of plasma levels of CTRP12. Conclusion: Finally, HbA1c was predictive of CTRP12 levels. It seems that CTRP12 could be considered as a novel biomarker for the prediction of T2D. Copyright: 2020 The Author(s); Published by Kerman University of Medical Sciences. This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Citation: Gorgani-Firuzjaee S, Khodabandehloo H. Circulating Levels of C1q/TNF-Related Protein-12 (CTRP-12) in Patients with Type 2 Diabetes: A Case-control Study. Journal of Kerman University of Medical Sciences , 2020; 27 (3): 262-269. Introduction Obesity-induced type 2 diabetes (T2D) is one of the most serious problems in the world. According to the WHO statistics, 422 million people worldwide suffered from diabetes in 2014 and it is estimated that there will be at least 629 million people living with diabetes by 2045 (1). Adipose tissue cytokines which are collectively called adipocytokines or adipokines are the main culprits leading to insulin resistance and beta cell dysfunction characterizing T2D (2). Among adipokines, adiponectin is one of the most potent molecules with respect to its anti-inflammatory and insulin sensitizing activity (2). A growing body of evidence indicates that adiponectin level is reduced in T2D (3-5). Despite its anti- inflammatory and insulin sensitizing properties, adiponectin gene knockout mice show surprisingly mild phenotypes (6-8). These findings suggest that there may be other factors that