The harmful habits (smoking, alcohol consumption), thyroid cancer and other chronic thyroid diseases risk

Background. Thyroid disorders are the second most common endocrine system disease after diabetes mellitus, placing a significant burden on society and healthcare systems. The incidence of thyroid diseases is increasing worldwide. This requires studying the impact of potential risk factors in order to develop effective prevention measures, particularly in countries with limited resources. The purpose of the study was to analyze the links between harmful habits (smoking, alcohol consumption), thyroid cancer and other chronic thyroid diseases. Materials and methods. During 2024–2025, a case-control study was conducted at the specialized endocrinology center in Kyiv. Ninety-five people with thyroid cancer and 505 patients with chronic thyroid diseases, such as non-toxic goiter, toxic adenoma, Graves’ disease, chronic autoimmune thyroiditis, were interviewed according to the original author’s program. The control group consisted of 172 practically healthy individuals. The comparison groups did not differ in age, gender, or place of residence (p > 0.05). Most respondents were women (75.0–78.9 %), people of working age (82.0–85.2 %), and urban residents (74.4–80.0 %). Results. Thyroid cancer and other chronic thyroid diseases are more common among women than men, while harmful habits (smoking and alcohol consumption) are more widespread among men. Smoking (current and former) is associated with a higher risk of chronic thyroid disease in men (odds ratio 2.58; 95% confidence interval 1.25–5.31) and women (2.03; 1.19–3.45), but no evidence of such an association was observed for thyroid cancer. Smoking for more than 10 years can play a significant role in the risk of developing thyroid cancer and other chronic thyroid diseases in women (7.88; 1.33–46.63 and 7.20; 1.58–32.88, respectively), and for thyroid cancer, the number of cigarettes per day (more than 10) also matters: 19.00; 1.97–183.44. No such patterns have been observed in men. Alcohol consumption in women increases the risk of both thyroid cancer (3.17; 1.68–5.98) and chronic thyroid diseases (1.89; 1.16–3.09), while in men, significant associations were found only between risky (several times a week) alcohol consumption and chronic thyroid diseases (3.21; 1.17–8.83; p < 0.05). Conclusions. Cancer and other chronic thyroid diseases in women are associated with the intensity and duration of smoking, as well as any alcohol consumption, while in men, this association is only found between smoking (current or former), risky alcohol consumption (several times a week), and chronic thyroid diseases. Further studies are needed to better understand this association.