Association Between Amino Acid Levels and Thyroid Function Among Iranian Adults: A Cross‐Sectional Analysis of Bushehr Elderly Health (
BEH
) Program
Mohamad Mehdi Khadembashiri, Kazem Khalagi, Shahrzad Mohseni, Alireza Amanollahi, Fatemeh Bandarian, Noushin Fahimfar, Iraj Nabipour, Mahnaz Pejman Sani, Farideh Razi ABSTRACT
Introduction
Thyroid hormones regulate key metabolic processes; however, the association between thyroid function and amino acid metabolism varies across studies. This study aimed to investigate the relationship between thyroid biomarkers and circulating amino acid concentrations in adults aged 50 years and older.
Methods
We initially enrolled a random subsample of 824 adults aged 50 years and older from the second recruitment of the Bushehr Elderly Health (BEH) Program. Because the clinical and subclinical hyperthyroidism groups were very small, 14 participants from these groups were excluded from the primary between‐group and regression analyses. Therefore, the primary analytical sample comprised 810 participants with euthyroid status, subclinical hypothyroidism, or clinical hypothyroidism. Associations between amino acid concentrations and thyroid biomarkers were assessed using multivariable linear regression models.
Results
The initial sample included 335 men and 489 women, with mean ages of 62.27 ± 8.57 and 61.47 ± 7.52 years, respectively. Although several nominal associations were observed between amino acids and TSH in crude or adjusted analyses, none remained statistically significant after false discovery rate (FDR) correction. No statistically significant differences in amino acid concentrations were observed between the thyroid disorder groups after FDR correction.
Conclusion
No statistically significant associations between amino acid concentrations and thyroid biomarkers remained after correction for multiple comparisons. Likewise, no significant differences in amino acid concentrations were observed between the examined thyroid disorder groups after FDR correction. Larger longitudinal studies are needed to determine whether the nominal findings observed in the present study are reproducible and biologically meaningful.