Marchetta, T Gamberi et al., "Reduced expression of thyroid hormone
receptors and beta-adrenergic receptors in human failing cardiomyocytes," Biochemical Pharmacology, vol.
resistance syndromes [by Refetoff S, Dumitrescu AM].
The drugs are designed to normalize the thyroid hormone
levels in the blood (i.e., to increase levels if they are high or decrease levels if they are low) and to control symptoms that are present.
Treatment with thyroid hormone
is usually started empirically and much effort has been put into estimating the accurate initial dosage.
However, the risks of low or high thyroid hormone
levels become much more apparent during pregnancy.
are associated with losing weight and having more energy, which may lead to people being treated at the high end of the normal range.' said Dr.
"We know patients with hypothyroidism have a higher risk of atrial fibrillation, but we didn't consider increased risk within what's considered the normal range of thyroid hormones
. These findings show we might want to reconsider what we call normal." said lead researcher Jeffrey L.
Martin Feller, M.D., from the University of Bern in Switzerland, and colleagues conducted a systematic literature review to identify randomized clinical trials that compared thyroid hormone
therapy to placebo or no therapy in non-pregnant adults with subclinical hypothyroidism.
In hypothyroidism, your body produces less thyroid hormone
than it needs.
According to the new study, researchers found that even more modest increases in thyroid hormone
were associated with an increased A-Fib risk.
have classified the patterns of abnormalities of thyroid hormone
levels in ESS into four major types namely low T3 syndrome, low T3 and low T4 syndrome, high T4 syndrome, other variants.3 Low T3 Syndrome is defined as a condition in which T3 is decreased but T4 and TSH levels remain normal due to the impaired conversion of the inactive pro-hormone T4 to the biologically active hormone T3 by 5 monodeiodinase in the liver.4 It is the most common abnormality amongst NTIs observed.