Salivary Lipid Peroxidation and Antioxidant Status in the Patients with Papillary Thyroid Carcinoma: A Case-Control Study

Abstract

Background: Oxidative stress has been shown to be the most significant influential factor in cancer pathogenesis. Follicular cells are affected in papillary thyroid carcinoma (PTC), which is the most prevalent thyroid cancer associated with oxidative stress. As a noninvasive source of body metabolism, saliva has recently attracted the attention of researchers as an investigative specimen. The present study aimed to evaluate and compare the levels of total antioxidant capacity (TAC) and malondialdehyde (MDA) in the blood and saliva samples of PTC patients and healthy control subjects. Methods: This case-control study was conducted on the patients with PTC referring to Taleghani Hospital in Tehran, Iran. Age- and gender-matched healthy volunteers were selected as the control group. Blood and saliva samples were obtained from all the subjects. Measurement of the MDA and TAC levels was performed using a commercial kit (ZellBio GmbH, Germany) based on colorimetric methods. Data analysis was performed in MedCalc software version 14.8.1. Results: In total, 33 PTC patients and 33 healthy subjects were enrolled in the study with the mean age of 34.6 ± 8.02 years. No statistically significant differences were observed in the demographic characteristics of the participants. Serum TAC and MDA levels were significantly lower and higher in the PTC group (P < 0.0001) compared to the control group (P = 0.0009), respectively. However, salivary TAC (P = 0.48) and MDA (P = 0.25) revealed no significant differences between the study groups. Conclusions: According to the results, PTC patients had oxidant/antioxidant imbalance, which could increase the risk of PTC. Furthermore, there were no significant differences in the TAC and MDA levels measured in the saliva of the PTC patients and control subjects. This finding could be attributed to the ultrafiltration in plasma, which involves the seeping-through of the plasma molecules, not allowing the use of saliva as a substitute for serum or plasma.