General Medicine

» Elaine Moore - Hyperthyroidism and running

In response to Hyperthyroidism and running posted by tdove52:
Hi,
Your elevated TSI and TBII levels suggest that you have both stimulating and blocking TSH receptor antibodies.
These antibodies sort of cancel each other out in that the blocking antibodies prevent TSI from stimulating thyroid cells to produce excess thyroid hormone.

TSH receptor antibodies are recognized by the pituitary gland (via its own TSH receptors) as if they were TSH. Thinking you have adequate TSH levels in your blood the pituitary slows down on TSH production and secretion. Consequently, TSH levels are falsely decreased and the test result is misleading.

Unfortunately, even though this is well known in research circles and the ATA even had an article on their website and in Clinical Thyroidology several years ago, many endos don't realize this. Labs are to blame since we mistakenly announced that TSH was the best indicator of thyroid function in all cases back when we first developed tests to measure TSH. In normal people, this fits. But in autoimmune thyroid disease TSH is frequently misleading.

A low TSH on its own doesn't do anything.
TSH normally orders thyroid cells to grow and produce and secrete thyroid hormone. When you have TSH receptor antibodies they take the place of TSH and they regulate your thyroid hormone levels.

In people without autoimmune thyroid disease the TSH level does usually reflect thyroid status. In your case, FT4 and FT3 levels are better indicators of thyroid status. Your low uptake suggests hypothyroidism or thyroiditis rather than hyperthyroidism. Probably, you have enough available TSI to keep your levels within range, and the blocking antibodies keep you from becoming hyperthyroid.

Strenuous running can trigger GD. But if you're well conditioned and you don't overdo it (where your heart rate isn't returning to normal) you can run. Many people with GD continue to run once their FT4 and FT3 levels are in control.

You should probably discuss this with your doctor again. If you're used to exercising you can experience stress if you're forced to avoid it. Best, Elaine