ABSTRACT
Background /Aims: Oxidative stress has been implicated in the pathogenesis of thyroid cancer and simple goiter among other diseases however; there has not been a direct comparison of the severity of the stress factor in these two conditions in relation to their dietary pattern in our environment. Objective: This study assessed oxidative stress indices, antioxidant status and dietary pattern in thyroid cancer and simple goiter compared with the controls. Study Design: This is a case-control study. Place and Duration of Study: Study groups were recruited from the Departments of Surgery and Nuclear medicine of University of Ilorin teaching hospital, Ilorin, Kwara State and University College Hospital, Ibadan, Oyo State respectively between March 2013 and September 2013. Materials and Methodology: A total number of one hundred and five (105) age matched participants consisting of 88 females and 17 males were recruited for this study. They were divided into 3 groups; Group one 35 participants with thyroid cancer and group two, 35 participants with simple goiter and group three, 35 control participants. Plasma levels malondialdehyde (MDA), hydrogen peroxide (H2O2) and total plasma peroxide (TPP) were determined by colorimetric methods. Antioxidant status was determined by measuring total antioxidant potential (TAP), glutathione peroxidase (GPx), Superoxide dismutase (SOD), reduced glutathione (GSH), glutathione-s-transferase (GST) by colorimetric methods. Selenium (Se) was determined by atomic absorption spectrophotometry (AAS).Oxidative stress index (OSI) was measured and all values expressed as mean ± SD, while frequency of intake of various dietary sources of the participants were collated. Results: TAP, SOD, GPx, GSH and GST (antioxidants) levels in group 1 (552.17±74.67; 1.30±0.32; 1.91±0.23; 4.47±0.59; 0.92±0.25; 1.28±0.04 respectively) were significantly lower than group 3 (933.51±80.15; 2.85±0.39; 5.40±0.76; 8.34±1.12; 2.11±0.31). While the mean plasma levels of antioxidants in group 2 (704.74±62.22; 2.01±0.27; 4.62±0.89; 6.19± 0.56; 1.47± 0.14 and 1.40±0.04) were significantly higher than that of group 1. However, significant increase was observed in mean levels of oxidative stress markers; TPP, MDA, H2O2 and OSI, in group 1 (16.24±2.52, 13.88±2.95, 13.52±6.91 and 2.93±1.40 respectively) compared to group 3 (4.57±1.32, 3.22±1.20, 3.01±0.86 and 0.48±0.14). Oxidative stress markers in group 2 (9.79±1.40, 5.90±1.13, 3.81±1.40 and 1.62±0.23) were significantly lower than group 1. A p - value <0.05 was considered significant. Majority of the control participants consumed fruits and vegetables (sources of exogenous antioxidants) regularly more than the test groups Conclusion: The study reported higher oxidative stress markers; oxidative stress index and lower antioxidant status in study subjects compared to controls .Oxidative stress appeared more marked in thyroid malignancy than the benign thyroid disease state. Adequate intake of fresh fruits and vegetables could be beneficial for thyroid cancer patients.