The relationship between physical activity and thyroid function in American adults: A survey from the NHANES database

Abstract

Abstract Objective Physical activity (PA) is closely related to our lives, and the effects of PA on thyroid function have not been elucidated. Methods Using data from the National Health and Nutrition Examination Survey (NHANES) 2007–2012, we included 5877 participants and analyzed the associations of thyroid function with weekly physical activity (PAM, expressed in metabolic equivalents of task) and physical activity time (PAT) in American adults. Univariate and multivariate logistic analyses were used to demonstrate the associations of PAM and PAT with the primary outcome. Linear regression analysis was performed to determine the associations between thyroid biochemical indicators/diseases and PAM/PAT. Results Our study revealed noticeable sex differences in daily PA among the participants. With the increase in PAM, the risk of overt hypothyroidism [p = 0.02, OR (95% CI) = 3.07 (1.24, 7.58)] and subclinical hyperthyroidism [p = 0.03, OR (95% CI) = 3.25 (1.12, 9.45)] increased in men. The risk of subclinical hyperthyroidism [p < 0.001, OR (95% CI) = 5.89 (1.85, 18.80)], overt hypothyroidism [p < 0.001, OR (95% CI) = 8.70 (2.80, 27.07)] and autoimmune thyroiditis (AIT) [p = 0.03, OR (95% CI) = 1.42 (1.03, 1.97)] increased with PAT in adult men. TSH, FT4, TT4, FT3, and TT3 levels also varied to a certain extent with changes in PAM and PAT. Conclusion The amount of daily physical activity of American adults has a certain influence on changes in thyroid function, including thyroid hormone levels and thyroid diseases. Higher PAM and PAT were strongly associated with the risk of clinical hypothyroidism, hyperthyroidism and AIT in men.