SAT-437 Influence of Smoking on Thyroid Function in Japanese Subjects: Longitudinal Study for One Year of On-Off Smoking

• Published in: Journal of the Endocrine Society 2020-05, Vol.4 (Supplement_1)
• Main Authors: Nakajima, Yasuyo, Yamada, Sayaka, Nishikido, Ayaka, Yoshioka, Masayuki, Katano-Toki, Akiko, Ishida, Emi, Yamada, Eijiro, Horiguchi, Kazuhiko, Yoshino, Satoshi, Matsumoto, Shunichi, Yamada, Masanobu
• Format: Article
• Language: English
• Subjects: Thyroid
• ISSN: 2472-1972; 2472-1972
• DOI: 10.1210/jendso/bvaa046.1544

Recent studies showed that various factors, including age, gender, race, iodine intake, obesity, the thyroid peroxidase antibody (TPO-Ab), and/or smoking, influence the thyroid status. In the present study, we analyzed and investigated the effects of these factors, particularly smoking and the thyroid peroxidase antibody (TPO-Ab) in Japanese euthyroxinemia individuals with serum free T4 level within normal range. A total of 12,289 subjects who underwent health check-ups were analyzed in a cross-sectional and longitudinal study. The mean age of subjects was 50 ± 10 years (age range: 21–88 years). Serum TSH levels and the prevalence of positivity for TPO-Ab increased with age in Japanese euthyroxinemia subjects. Mean and median serum TSH levels increased with age in smokers and non-smokers, but were significantly lower in smokers than in non-smokers among men and women in most age groups; the median 97.5th percentiles of TSH levels were 1.2 mU/liter and 2.9 mU/liter in smokers, and 1.4 mU/liter and 3.9 mU/liter in non-smokers in 31- to 40-year-old men, p