Menopausal Transition and Thyroid Dysfunctions

Thyroid dysfunction is common in the general population especially in women. All thyroid diseases are infact more common in women than in men. In postmenopausal and elderly women, the incidence of hypothyroidism, hyperthyroidism and cancer (most thyroid diseases) is highest than in younger women. Studies on the relationship between menopausal transition and thyroid function are few and do not allow to clarify whether menopause has an effect on the thyroid regardless of aging. Thyroid hormone production, metabolism, and action change with aging. The reference ranges for serum thyrotropin and thyroid hormones are derived mainly from younger populations. Thus, the prevalence of subclinical thyroid dysfunction is increased greatly in the elderly. However, it is unclear whether mild thyroid dysfunction in the elderly is associated with adverse outcomes. The interpretation of thyroid function tests should be cautiously made during the perimenopause and post-menopause period. The diagnosis of thyroid dysfunction in postmenopausal women is difficult because the symptoms can be non-specific or common with menopausal complaints. There is no consensus for screening post-menopausal women even though there is well-known evidence about unrecognised thyroid dysfunction leads to increased: cardiovascular risk, bone fractures, cognitive impairment, depression, and mortality. Thyroid function is not directly involved in the pathogenesis of the complications of menopause. However, coronary atherosclerosis and osteoporosis may be aggravated in the presence of hyperthyroidism or hypothyroidism. Therapy of thyroid dysfunction is different in postmenopausal and elderly women than in young people. Hypothyroidism should be treated with caution, because high doses of L-thyroxine can lead to cardiac arrhythmias and increased bone turnover. Hyperthyroidism should be preferentially treated with radioiodine. Thyroid status beneficially influencing longevity relates to low thyroid function in elderly women. Cancer often affects women over 50 years old. The diagnostic and therapeutic approach is the same as in the general population, but the surgical risk and cancer prognosis is worse than in young patients. Decision for menopausal hormonal replacement therapy (HRT) should be individualized regardless of the concomitant presence of thyroid disorders. Women with any form of thyroid disease should be treated according to the current HRT guidelines. The effects of postmenopausal estrogen replacement on thyroxine requirements in women with hypothyroidism should be considered.