PAIN JOINTS SPINE · Oct 14, 2026
Serum Free Triiodothyronine and Free Thyroxine Across Menopausal Status: A Comparative Cross-Sectional Study
By Dadel EV, Oraon APO, Aziz T
Background: Menopause occurs during a period of substantial chronological ageing, making it difficult to separate changes associated with ovarian ageing from those associated with increasing age. Across adulthood, free triiodothyronine (FT3) tends to decline, whereas findings for free thyroxine (FT4) are less consistent. This study compared serum FT3 and FT4 concentrations in premenopausal and postmenopausal women and explored their relationships with age.|Methods: A comparative cross-sectional study was performed in 100 premenopausal women aged 20–30 years and 100 postmenopausal women aged 50–60 years attending outpatient departments at Rajendra Institute of Medical Sciences, Ranchi, India, between January 2018 and October 2019. Participants with diabetes mellitus, hypertension, endocrine disease, pregnancy, premature menopause, previous hysterectomy, hormone replacement therapy, or medication exposure known to affect thyroid-function testing were excluded. Serum FT3 and FT4 were estimated using a chemiluminescent microparticle immunoassay. Group differences were examined with the independent-samples t-test, and Pearson correlation was used to evaluate associations with age.Results: FT3 concentrations were lower in postmenopausal women than in premenopausal women (2.21 ± 0.39 vs 2.66 ± 0.49 pg/mL; p<0.001). FT4 concentrations were comparable between the groups (0.96 ± 0.13 vs 0.98 ± 0.11 ng/dL; p=0.308). FT4 remained within the laboratory reference interval in all participants. FT3 was below the reference interval in five postmenopausal and three premenopausal women, while one premenopausal participant had an FT3 value above the interval. Neither FT3 nor FT4 showed a significant within-group association with age.Conclusions: The postmenopausal group had lower FT3 concentrations, whereas FT4 concentrations were similar between groups. Because menopausal status and age were closely linked by the study design, the observed FT3 difference cannot be attributed specifically to menopause. The findings are more appropriately viewed as a difference between menopausal-age groups and may reflect age-related changes in peripheral thyroid hormone metabolism. Longitudinal studies covering the menopausal transition are required to distinguish these effects.