Women in the late menopause transition and postmenopause phases are more likely to develop hypothyroidism than the premenopausal women, according to a study reported in the journal Thyroid.¹

This cross-sectional study included 53,230 women from the Kangbuk Samsung Health Study, aged ≥40 years, who underwent a health examination between 2014 and 2018. The menopausal transition and postmenopause phases were divided into four (early and late) as per the Stages of Reproductive Aging Workshop + 10 criteria. Serum thyroid-stimulating hormone (TSH), free thyroxine (T4) and free triiodothyronine (T3) levels were measured via electroluminescence immunoassays. The objective of the study was to determine thyroid dysfunction in the menopausal stages vis-à-vis in the premenopause.

According to the study, overt hypothyroidism was significantly more common in the late transition and postmenopausal periods than in premenopause with adjusted prevalence ratios of 1.61 and 1.66, respectively. Similarly, compared to premenopause, the prevalence of subclinical hypothyroidism was significantly high in the late transition (aPR 1.22) and postmenopause (aPR 1.24). These associations remained significant even after adjusting for variables such as age, physical activity, BMI, parity, level of education, alcohol intake, smoking, age at menarche, center, year of examination. However, no such associations were seen for subclinical and overt hyperthyroidism during any state of menopause.

The levels of free T4 were comparable between premenopause and postmenopause, while free T3 and TSH levels were highest in the late menopause transition and postmenopause period with aPRs of 1.26 and 1.29, respectively. Free T4 levels were lower during late perimenopause (aPR 1.76) and postmenopause (aPR = 1.9) than in premenopause. Free T3 levels were also lower in late perimenopause than in premenopause (aPR 2.4).

This study highlights that abnormal thyroid function in the form of overt and subclinical hypothyroidism commonly occurs in the late menopausal transition than in the other stages of menopause and according to the authors, this is the stage “during which various menopausal symptoms and measurable physiologic changes are likely to manifest”. Since the symptoms of menopause and hypothyroidism overlap, all women should be evaluated for thyroid dysfunction during transition to menopause.

Reference

1. Yejin K, et al. Menopausal stages and prevalence of thyroid dysfunction. Thyroid. 2022 Mar 16. doi: 10.1089/thy.2021.0544.