The prevalence of hypothyroidism — overt and subclinical — is higher among women during the late menopause transition and postmenopause compared with premenopause, according to study findings.
Mira Kang
Seungho Ryu
“Accumulated data on menopausal transition suggest that the late menopausal transition stage, among other stages, seems to be the most critical period during which various menopausal symptoms and measurable physiologic changes are likely to manifest,” Mira Kang, MD, PhD, associate professor and vice chief information officer of the data management committee at Samsung Medical Center in Seoul, South Korea, and Seungho Ryu, MD, PhD, professor at the Center for Cohort Studies, Total Healthcare Center at Kangbuk Samsung Hospital, told Healio. “Our findings add to the existing line of evidence, reflecting an increasing trend in the occurrence of abnormal thyroid function in the late menopausal stage. It would be of interest to find out what mechanisms or factors play into the increased prevalence of the hypothyroid state during the late transition period in future investigations.”
Kang, Ryu and colleagues collected data from 53,230 women aged 40 years or older (mean age, 47.1 years) who participated in the Kangbuk Samsung Health Study at the Kangbuk Samsung Hospital Total Healthcare Center in Seoul and Suwon, South Korea, and had a health examination performed between 2014 and 2018. The Stages of Reproductive Aging Workshop + 10 criteria were used to determine menopausal stages. Electroluminescence immunoassays were conducted to measure serum thyroid-stimulating hormone, free thyroxine and free triiodothyronine levels.
The findings were published in Thyroid.
Free T3 and TSH levels were highest in the study cohort during postmenopause. Free T4 levels were similar between premenopause and postmenopause.
In multivariable-adjusted analysis, the prevalence of overt hypothyroidism was higher in late perimenopause (adjusted prevalence ratio [aPR] = 1.61; 95% CI, 1.12-2.3) and postmenopause (aPR = 1.66; 95% CI, 1.16-2.37) compared with premenopause (P = .002). Similarly, the prevalence of subclinical hypothyroidism was higher during late perimenopause (aPR = 1.22; 95% CI, 1.06-1.4) and postmenopause (aPR = 1.24; 95% CI, 1.07-1.44) compared with premenopause (P = .001). No increased prevalence in overt and subclinical hyperthyroidism was observed during the different menopausal stages.
“There is substantial resemblance between symptoms of menopause and those of thyroid abnormalities, such as weight gain, fatigue, cold intolerance, mood swings and anxiety,” Kang and Ryu said. “Thus, existing thyroid problems may easily go overlooked, thereby delaying treatment. Thyroid dysfunction, if left untreated, may be associated with significant morbidity and impaired quality of life, and, in women approaching menopause, thyroid dysfunction may exacerbate certain menopausal symptoms. Therefore, it is critical that the prevalence and risk distributions of thyroid abnormalities across different stages of menopausal transition be clearly defined to facilitate timely intervention.”
More women had a serum TSH level of greater than 5 IU/mL during late menopause transition (aPR = 1.26; 95% CI, 1.11-1.43) and postmenopause (aPR = 1.29; 95% CI, 1.13-1.48) compared with premenopause (P < .001). A higher prevalence of low free T4 levels was observed during late perimenopause (aPR = 1.76; 95% CI, 1.24-2.51) and postmenopause (aPR = 1.9; 95% CI, 1.34-2.68) compared with premenopause (P < .001). Women were more likely to have low free T3 levels of less than 2 pg/mL during late perimenopause compared with premenopause (aPR = 2.4; 95% CI, 1.36-4.23; P =.014).
Kang and Ryu said longitudinal studies are needed to assess temporal associations between menopausal stages and thyroid function.
“In addition, the clinical and prognostic significance of thyroid dysfunction in women during the menopausal transition should also be explored.” Kang and Ryu said. “Lastly, since our population consisted of Korean women, our findings need to be extended to populations of other ethnicities.”
PERSPECTIVE
Thyroid dysfunction is common in women and frequently manifests at the time of puberty, pregnancy and menopause. Symptoms related to menopause and thyroid disorders can overlap, leading to delayed diagnosis and treatment of underlying thyroid disease. There are data suggesting that adequate treatment of thyroid disorders can improve climacteric symptoms, thereby improving quality of life and possibly reducing the need for estrogen supplementation.
The authors conducted a cross-sectional study of 53,230 Korean women aged 40 years or older and stratified them by menopausal stages. Thyroid hormone levels were measured, and an increased prevalence of overt and subclinical hypothyroidism was observed in the late transition and postmenopausal stages. Subclinical and overt hyperthyroidism were not associated with menopause.
Current guidelines do not recommend routine screening for thyroid dysfunction in asymptomatic individuals. However, case-finding is recommended in women at increased risk for hypothyroidism or with symptoms. Diagnosis of thyroid disorders during menopause is important as thyroid hormone concentration can affect the intensity and frequency of menopausal symptoms. In addition, undiagnosed thyroid disease can affect cardiovascular health and increase long-term morbidity. This study suggests that screening women for thyroid dysfunction during the menopausal transition is prudent.
Arti Bhan, MD, FACE
Endocrine Today Editorial Board Member
Division Head, Endocrinology
Henry Ford Health System
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