Because (a) burnout overlaps with depression and (b) depression has been associated with altered functioning of the hypothalamic-pituitary-thyroid axis changes in the activity of the HPT axis can be expected in burnout. Most probably, Guo et al.’s (2017) results are flawed by a severe form of the “healthy worker effect.”
Bianchi, R., Schonfeld, I.S., & Laurent, E. (2017). Burnout and the hypothalamic-pituitary-thyroid axis: A methodological comment. Psychoneuroendocrinology, 78, 254-255. doi: 10.1016/j.psyneuen.2017.02.007.