Thyroid function and postmenopause

Abstract

There is an increasing prevalence of high levels of thyroid stimulating hormone (TSH) with age - particularly in postmenopausal women - which are higher than in men. The incidence of thyroid disease in a population of postmenopausal women is as follows: clinical thyroid disease, about 2.4%; subclinical thyroid disease, about 23.2%. Among the group with subclinical thyroid disease, 73.8% are hypothyroid and 26.2% are hyperthyroid. The rate of thyroid cancer increases with age. The symptoms of thyroid disease can be similar to postmenopausal complaints and are clinically difficult to differentiate. There can also be an absence of clinical symptoms. It is of importance that even mild thyroid failure can have a number of clinical effects such as depression, memory loss, cognitive impairment and a variety of neuromuscular complaints. Myocardial function has been found to be subtly impaired. There is also an increased cardiovascular risk, caused by increased serum total cholesterol and low-density lipoprotein cholesterol as well as reduced levels of high-density lipoprotein. These adverse effects can be improved or corrected by L-thyroxine replacement therapy. Such treatment has been found to be cost-effective. With time, overt hypothyroidism can develop. Therefore, routine screening of thyroid function in the climacteric period to determine subclinical thyroid disease is recommended. Hormone replacement therapy (HRT) in women with hypothyroidism treated with thyroxine causes changes in free thyroxine and TSH. Increased binding of thyroxine to elevated thyroxine-binding globulin causes an elevation of TSH by feedback. Since adaptation is insufficient, there is an increased need for thyroxine in these women taking HRT. TSH levels should be controlled at 12 weeks after the beginning of therapy. At higher age the need for iodine and thyroxine is decreased. Therefore, therapy has to be controlled. For bone metabolism thyroid hormones play a dominant role. While there are only marginal differences between hypothyroid patients and euthyroid controls, there are large differences for hyperthyroid patients. Previous thyrotoxicosis and subsequent long-lasting L-thyroxine treatment are together associated with reduction in femoral and vertebral bone density in postmenopausal women. In these cases HRT is important for the control of bone loss.

Functional Characterization of 5-Oxoproline Transport via SLC16A1/MCT1

“…We also studied the effects of hormones as SLC16A2 substrates, including T3 and T4, on transport of 5-oxoproline via SLC16A1. It is of importance that even mild thyroid failure can have a number of clinical effects such as depression, memory loss, cognitive impairment, and a variety of neuromuscular complaints (38,39). Under the experimental conditions used in our study, we could not detect any interaction of thyroid hormones with SLC16A1.…”

Powiązania między zespołem metabolicznym, subkliniczną niedoczynnością i autoimmunologicznym zapaleniem tarczycy u kobiet po menopauzie oraz rola interleukiny-6

“…It remains unclear if thyroid subclinical dysfunction accelerates the development of metabolic syndrome and whether menopause per se has an effect on the thyroid function regardless of aging. It has been estimated that 5-23% of postmenopausal women develop subclinical hypothyroidism, and this frequency increases with age [11]. Woeber reported that subclinical hypothyroidism occurs in at least 10% of women after the age of 60 years [12].…”

Prevalencia de hipotiroidismo y su asociación con factores de riesgo cardiometabólicos en mujeres adultas argentinas

“…Los signos y síntomas del hipotiroidismo suelen ser difíciles de diferenciar clínicamente de los presentes en el síndrome del climaterio y el envejecimiento, por lo que se puede dificultar el diagnóstico de la enfermedad 9,10 . El hipotiroidismo se asocia con factores de riesgo cardiometabólicos como hipertensión arterial (HTA), dislipemia, inflamación sistémica y resistencia a la insulina (RI), siendo considerada esta disfunción tiroidea factor independiente para el desarrollo de enfermedad cardiovascular 11,12,13 .…”