Association between lifestyle factors and thyroid function in young euthyroid adults Merchán Ramírez, Elisa Sanchez‑Delgado, Guillermo Jurado Fasoli, Lucas Acosta Manzano, Francisco Miguel Muñoz Torres, Manuel Eduardo Llamas Elvira, José Manuel Ruiz Ruiz, Jonatan Thyroid hormones Dietary intake Sleep Physical activity Euthyroid This work is part of a PhD thesis conducted within the framework of the Biomedicine Doctoral Studies Program of the University of Granada, Spain. This study was funded by the Spanish Ministry of Economy and Competitiveness via the Fondo de Investigación Sanitaria del Instituto de Salud Carlos III (PI13/01393), by the Retos de la Sociedad program (DEP2016-79512-R), European Regional Development Funds (ERDF), the Spanish Ministry of Education (FPU13/04365 and FPU19/01609), the Fundación Iberoamericana de Nutrición (FINUT), the Redes Temáticas de Investigación Cooperativa RETIC (Red SAMID RD16/0022), the AstraZeneca HealthCare Foundation, the University of Granada Plan Propio de Investigación 2016-Excellence actions: Unit of Excellence on Exercise and Health (UCEES)-and Plan Propio de Investigación 2018-the Programa Contratos-Puente and Contratos Perfeccionamiento de Doctores, the Junta de Andalucía, Consejería de Conocimiento, Investigación y Universidades (ERDF; ref. SOMM17/6107/UGR), and the Fundación Alfonso Martín Escudero (grant awarded to GSD). Data availability The datasets generated and/or analyzed during this study are available upon reasonable request. Clinical trial registry: NCT02365129 (ClinicalTrials.gov). Appendix A. Supplementary data Supplementary data associated with this article can be found, in the online version, at http://doi.org/10.26599/FSHW.2022.9250022. Purpose The present work examines the associations of dietary habits, sedentarism, physical activity (PA) levels and sleep habits, with thyroid function in young euthyroid adults. Methods A total of 105 young euthyroid adults participated in this cross-sectional study. Thyroid function was determined in fasting conditions (> 6 h). Dietary habits were measured by a food frequency questionnaire and three non-consecutive 24 h recalls, and different dietary intake and patterns were then estimated. The time spent in sedentary, PA levels and sleep habits were objectively measured using a wrist-worn accelerometer. Results Energy and carbohydrate intake were positively associated with thyroid stimulating hormone (TSH) (β = 0.222; R2 = 0.102; P = 0.022 and β = 0.425; R2 = 0.129; P = 0.007, respectively) whereas fat intake was negatively associated with TSH (β = −0.428; R2 = 0.137; P = 0.004). Energy intake was also positively associated with free triiodothyronine (β = 0.277; R2 = 0.137; P = 0.004). Further, adherence to the Mediterranean diet was negatively related to TSH and free thyroxine (FT4) (β = −0.221; R2 = 0.113; P = 0.020 and β = −0.268; R2 = 0.071; P = 0.007, respectively). Vigorous-intensity and overall PA were negatively associated with FT4 (β = −0.227; R2 = 0.052; P = 0.022 and β = −0.204; R2 = 0.042; P = 0.041, respectively). In contrast, no associations were found between sleep parameters and thyroid function. Conclusions Lifestyle factors such as dietary intake and PA levels seems to be related to thyroid function even in young euthyroid adults. 2023-09-08T10:48:18Z 2023-09-08T10:48:18Z 2023-06-01 info:eu-repo/semantics/article E. Merchan-Ramirez et al. / Food Science and Human Wellness 13 (2024) 265-275 [http://doi.org/10.26599/FSHW.2022.9250022] https://hdl.handle.net/10481/84324 10.26599/FSHW.2022.9250022 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess Attribution-NonCommercial-NoDerivatives 4.0 Internacional Tsinghua University Press