Objective: Toxic multinodular goitre (TMG) is known to be a frequent endocrine pathology. Increased thyroid hormones cause excess oxygen consumption; therefore, free radical generation increases. Consequently, oxidative stress, which has been implicated in several disorders, develops. Recently, homocysteine also was shown as a prooxidant. The aim of the present study was to compare first diagnosis, pre-operative and postoperative levels of MDA, homocysteine and thyroid hormones and to investigate the benefits of these parameters in diagnosis.

Material and Method: Present study was carried out on 24 female patients diagnosed with toxic multinodular goitre; and they were divided into three groups as first diagnosis (TMG), medical treated (pre-operative; TMG-Pr) and post-operative (TMG-Po). Thyroid hormones of patients were determined with IMMULITE 2000 hormone auto-analyzer; homocysteine levels were determined by using Elx-800 system and MDA levels were determined with the manual spectrophotometric method of Satoh.

Results: Homocysteine levels of TMG, TMG-Pr and TMG-Po were determined as 8.1±1.9; 10.1±1.8 and 10.5±2.6 µmol/L, respectively. The levels of MDA were determined; there was an increase in TMG group (1.9±0.4 nmol/ml) and a decrease in TMG-Pr (1.0±0.8 nmol/ml) and TMG-Po (1.1±0.7 nmol/ml) groups. These two parameters were changed significantly in both TMG-Pr and TMG-Po groups, compared with TMG group (p<0.05).

Conclusion: In the present study, plasma MDA levels were higher and homocysteine levels were lower in the pre-treated group compared with the treated group. These results can be due to the catabolism of homocysteine with the increased glomerular filtration rate because of the high basal metabolic activity in TMG group. ©2004, Fırat Üniversitesi, Tıp Fakültesi