Search

Adequate thyroid hormone availability is important for an uncomplicated pregnancy and optimal fetal growth and development. Overt thyroid disease is associated with a wide range of adverse obstetric and child development outcomes. An increasing number of studies now indicate that milder forms of thyroid dysfunction are also associated with these adverse pregnancy outcomes. The definitions of both overt and subclinical thyroid dysfunction have changed considerably over the past few years, as new data indicate that the commonly used fixed upper limits of 2.5 mU/l or 3.0 mU/l for thyroid-stimulating hormone (TSH) are too low to define an abnormal thyroid function. Furthermore, some studies now show that the reference ranges are not necessarily the best cut-off for identifying pregnancies at high risk of adverse outcomes. In addition, data suggest that thyroid peroxidase autoantibody positivity and high or low concentrations of human chorionic gonadotropin seem to have a more prominent role in the interpretation of thyroid dysfunction than previously thought. Data on the effects of thyroid disease treatment are lacking, but some studies indicate that clinicians should be aware of the potential for overtreatment with levothyroxine. Here, we put studies from the past decade on reference ranges for TSH, determinants of thyroid dysfunction, risks of adverse outcomes and options for treatment into perspective. In addition, we provide an overview of the current views on thyroid physiology during pregnancy and discuss strategies to identify high-risk individuals who might benefit from levothyroxine treatment. [ABSTRACT FROM AUTHOR]

The overall prevalence of thyroid hormone use in an unselected population of older adults (n = 2575; average age, 68.6 years) was 6.9% (10.0% in women and 2.3% in men). Eighty-one percent of women taking it were doing so for appropriate indications, eg, hypothyroidism, while 12% were not, eg, for obesity or high serum cholesterol; more men (29%) were taking it inappropriately. Inappropriate use was associated with desiccated thyroid more than with thyroxine. After follow-up averaging 6.9 years, 58% of inappropriate users were still taking it. Underuse also occurred. Thirty-seven percent of those definitely hypothyroid had a clearly elevated serum thyrotropin level (greater than 10 mU/L) despite thyroid therapy. Thyroid therapy is common in the elderly; most is appropriate. When inappropriate use occurs, it is more common in men and more often associated with desiccated thyroid, still commonly used in this age group. In chronic users of thyroid hormone, it is important to review currently appropriate indications and to measure serum thyrotropin levels to assess the adequacy of treatment of primary hypothyroidism. [ABSTRACT FROM AUTHOR]