Background/Aim: Metabolic syndrome (MetS) stands as a significant risk for developing various severe health problems. Therefore, the discovery of biomarkers capable of predicting the progression of metabolic conditions is crucial for improving overall health outcomes. Recently, we reported that coiled-coil domain containing 25 (CCDC25) might be associated with key proteins involved in metabolic pathways, by bioinformatics analysis. Thus, we assumed that serum CCDC25 levels might have an association with MetS status. Patients and Methods: In this study, based on the modified National Cholesterol Education Program-Adult Treatment Panel III (modified NCEP-ATP III) criteria, the participants who had three or more of abnormal criteria were defined as MetS, and those who had 1 or 2 abnormal criteria as pre-MetS groups; those who had no abnormal criteria were classified as the healthy control (HC) group. Serum CCDC25 levels were measured using the dot blot assay. Results: The results showed that serum CCDC25 levels of the MetS group (0.072±0.026 ng/μl) were significantly higher (p<0.001) than that of pre-MetS (0.031±0.011 ng/μl) or HC groups (0.018±0.007 ng/μl). We can discern a consistent trend indicating that serum CCDC25 level is well correlated with the number of abnormal criteria of MetS of each participant. Although serum CCDC25 levels correlated with the distribution of all 5 MetS criteria, the highest correlation was seen in serum CCDC25 levels and triglyceride (TG) levels, with r=0.563, followed by systolic blood pressure (SBP) levels (r=0.
557) and high-density lipoprotein-cholesterol (HDL-C) levels (r=-0.545). Conclusion: CCDC25 showed correlations with all MetS parameters, particularly with TG, SBP, and HDL-C. This prompts speculation that heightened CCDC25 levels may indicate the development and/or progression of those MetS-associated diseases.Metabolic syndrome (MetS) is a cluster of interconnected conditions that significantly raise the risk of developing severe health problems (1-4). MetS is defined based on the modified National Cholesterol Education Program-Adult Treatment Panel III (modified NCEP-ATP III) guidelines, and the individuals having three or more of the following five criteria are diagnosed as having MetS; abdominal obesity (BMI ≥27 kg/m 2 in males or ≥25 kg/m 2 in females) (5, 6), high blood pressure (BP ≥130/85 mmHg), elevated fasting blood glucose levels (FBG ≥100 mg/dl), increased triglyceride levels (TG ≥150 mg/dl), and decreased levels of high-density lipoprotein cholesterol (HDL-C <40 mg/dl in males or <50 mg/dl in females) (2). The prevalence of MetS ranges from 12% to 37% in the Asian population, although it varies depending on the criteria and regions (7). As mentioned above, MetS serves as a significant risk factor for non-communicable diseases (NCDs), including chronic disease (8), type 2 diabetes mellitus (9, 10), cardiovascular 785