|
Older women who are on both estrogen
replacement and thyroid replacement therapy may need a boost
to the thyroid portion of their regimen, new research suggests.
Increased estrogen, according to one investigator, can lower
thyroid levels in some women being treated for already-low
concentrations of the hormone.
To be safe, women taking thyroid hormones
should receive check-ups within a few months of starting
estrogen replacement.
The study
was funded by Knoll Pharmaceutical, which manufactures Synthroid™.
Thyroid hormone is used to treat hypothyroidism,
a condition in which the body's levels of the hormone are
too low. The thyroid gland
acts like a barometer -- churning out, as needed,
hormones that help regulate a range of vital functions including
-
heart
rate
-
blood
pressure
-
body
temperature
-
metabolism
An underactive or non-functioning gland
produces little or no thyroid hormone, triggering
symptoms such as
-
sluggishness
-
chills
-
constipation
-
weight
gain
Increases in estrogen, such as those
that occur in pregnancy, lead to dips in thyroid levels.
Among women with normal thyroid function, the gland can
compensate and produce more thyroid hormone. But this barometer
does not work in women with hypothyroidism.
The author recommends that women receiving
both types of hormone replacement have their thyroid levels
checked within 12 weeks of starting on estrogen -- particularly
women who are on thyroid hormone as part of thyroid cancer
treatment.
The New
England Journal of Medicine June 7, 2001; 344: 1743-1749,
1784-1785
|