Association Between Free Triiodothyronine and Carcinoembryonic Antigen Levels in Type 2 Diabetes Mellitus Patients.

Background: Thyroid dysfunction is more common in other endocrine disorders such as diabetes mellitus (DM). Carcinoembryonic antigen (CEA), a common tumor biomarker, is found elevated in patients with thyroid dysfunction. However, the relationship between thyroid hormone levels and CEA levels remains unclear.

Methods: In total, 663 patients with type 2 diabetes at the Tongzhou Branch of Dongzhimen Hospital were enrolled in this retrospective study. Data were collected from inpatient electronic files between December 2011 and December 2019. Laboratory indices were statistically analyzed using logistic regression and Spearman correlation analyses.

Results: In our study, total triiodothyronine (TT3), free triiodothyronine (FT3), serum albumin(ALB), total protein (TP), and triglyceride (TG) levels were significantly higher in the T2DM patients with normal values of CEA than T2DM patients who had abnormal values of CEA, whereas alkaline phosphatase (ALP), Glucose (GLU), and HbA1c levels were significantly increased in the T2DM patients with abnormal CEA level. Binary logistic regression analysis demonstrated that FT3, GLU, HbA1c, and TG levels remained as independent risk factors for CEA in patients with T2DM (β=-0.907, P =0.004; β =-1.009, P=0.004; β =0.090, P = 0001; β= 0.336, P <0.001; β= -0.293, P =0.009, resp). Spearman correlation analysis showed that CEA level was significantly positively correlated with HbA1c and GLU (r value: 0.265, P <0.001; r value: 0.270, P <0.001, resp.) and negatively correlated with FT3 and TG levels (r value: -0.139, P <0.001; r value: -0.103 P =0.008, resp). Furthermore, multivariate logistic regression analysis indicated that the FT3 quartiles were significantly associated with CEA levels before and after adjusting for confounding factors.

Conclusion: Our study determined that FT3 remained an independent risk factor for CEA in patients with T2DM and was significantly negatively correlated with CEA levels.