Does smoking affect thyroid gland enlargement and nodule formation in iodine-sufficient regions?

The present study aimed to investigate the effect of smoking on thyroid nodule formation and goiter development in healthy subjects living in Istanbul, an iodine-sufficient region. This study was designed as a prospective, randomized, and observational study.

Included in the study were voluntary hospital staff and relatives of patients between the ages of 28 and 71 who had no known disease or drug use, who have been living in Istanbul and had been smoking more than 10 cigarettes per day for at least 10years. Nonsmoker volunteers (45) shared similar demographic characteristics and were matched for age to the (46) smokers. By means of thyroid ultrasounds performed in all participants, volumes of the right and left lobes of the thyroid gland, and number, diameter and characteristics of nodules were evaluated.

Comparing the smokers and nonsmokers, no statistically significant difference was determined in terms of presence of nodules and volumes of the left and right thyroid lobes (P=0.68, P=0.09, and P=0.63, respectively). Making enhanced diffuse enlargement of the thyroid gland, but not to a statistically significant degree. Smoking was observed to have no effect on non-toxic nodules, or the levels of thyroid-stimulating hormone, free thyroxin, free triiodothyronine, anti-thyroid peroxidase, or anti-thyroglobulin antibodies.

Smoking does not effect, to a statistically significant degree goiter development thyroid nodule formation in iodine-sufficient regions like Istanbul.