Association between oxidative balance score and thyroid function and all-cause mortality in euthyroid adults.

Area of Science:

• Endocrinology
• Nutritional Science
• Epidemiology

Background:

• Thyroid function within reference ranges can influence mortality risk.
• Oxidative balance score (OBS) is a measure of the body's redox status.
• Understanding the interplay between oxidative balance, thyroid hormones, and mortality is crucial.

Purpose of the Study:

• To investigate the association between OBS, free thyroxine (FT4), and thyrotropin (TSH) in euthyroid adults.
• To analyze the relationship between OBS, FT4, TSH, and all-cause mortality.
• To explore the mediating role of FT4 in the association between OBS and mortality.

Main Methods:

• Utilized data from 5727 euthyroid adults in the National Health and Nutrition Examination Survey (NHANES).
• Employed weighted linear regression to assess OBS association with FT4 and TSH.
• Applied COX proportional hazard models and restricted cubic spline (RCS) for mortality analyses.

Main Results:

• A negative association was observed between OBS and serum FT4 concentrations ($-2.95%$).
• Higher FT4 levels (Q4 vs. Q1) were linked to increased all-cause mortality (HR 1.40).
• Higher OBS (Q4 vs. Q1) was associated with a reduced risk of all-cause mortality (HR 0.69).

Conclusions:

• OBS is negatively associated with serum FT4 in euthyroid adults.
• Both OBS and FT4 levels are significantly associated with all-cause mortality.
• FT4 partially mediates the effect of OBS on all-cause mortality, suggesting a complex relationship.