Association of shift work and shift patterns with thyroid function

This cross-sectional study examined the association between shift work and thyroid function using data from the National Health and Nutrition Examination Survey 2007 to 2010. Weighted univariate and multivariate regression models were applied, with additional subgroup and interaction analyses performed. A total of 3578 participants were included (mean age 41.17 ± 13.31 years). After adjusting for potential confounders, shift workers exhibited significantly higher levels of thyroid-stimulating hormone (TSH) (β = 0.30; 95% CI: 0.14–0.45), thyroglobulin antibody (TgAb) (β = 11.62; 95% CI: 3.49–19.74), and thyroid peroxidase antibody (TPOAb) (β = 8.74; 95% CI: 1.07–16.40), alongside an increased prevalence of autoimmune thyroiditis (AIT) (OR = 1.69; 95% CI: 1.26–2.26) compared with day workers (all P < .05). Analyses stratified by shift type revealed that regular evening shifts were most strongly associated with elevated TSH (β = 0.58), subclinical hypothyroidism (SCH) (OR = 2.63), and AIT (OR = 2.29). Additionally, rotating shifts were specifically linked to higher TgAb levels and AIT risk. These findings indicate that shift work, particularly evening and rotating shift patterns, is associated with adverse thyroid-related outcomes.