Wednesday, October 1, 2014
Testing Results and Hypothyroidism
I am a 49 year old female. I developed swelling of the face, particularly swelling in one eyelid, weight gain and extreme fatigue two months ago, with symptoms consistent with hypothyroidism. Blood tests showed a TSH of 3.56, but the doctor said it was normal. I went to another doctor and she run more tests. The TSH was 2.46 and it showed antibodies to thyroglobulin (high, out of reference) only, but the other thyroid tests were normal (T3, T4, etc.) This doctor also ordered a urine cortisol test because she said Cushing Syndrome can cause similar face swelling symptoms. The cortisol test came back high (90 in a 50 ref. range). She referred me to an endocrinologist.
The endocrinologist looked at the tests and said my thyroid was fine. When I asked why I had high antibodies to thyroglobulin he said it was not significant because many people have these antibodies and do not have thyroid problems. He said I did not have antibodies to thyroid peroxidase (lab result was 10 in reference range 20) and that would rule out autoimmune thyroid disease. I asked him why then my voice had changed and I was hoarse often. He felt my thyroid and said it was normal in size and I should see a throat doctor for my hoarseness. He said he was most concerned about my high cortisol and said I needed to repeat this test to make sure it was accurate.
My question is, if the thyroid is enlarged or underfunctioning, would this increase cortisol? I also had sarcoidosis as a child (although I recovered) and I am not sure if this has anything to do with my problems. Is there any connection between high cortisol and thyroid disease? Are these problems related or unrelated? It seems to me that a TSH in the range of 2.46 to 3.56 plus antibodies to thyroglobulin and symptoms consistent with hypothyroisdism suggest some kind of thyroid impairment (I also have mild anemia and elevated cholesterol, more frequent periods). Yet this endo doctor claimed that only having thyroid peroxidase antobodies would be significant. I have also read that high cortisol and thyroglobulin antibodies would interfere with the TSH result. Is this doctor correct in his antibody, TSH interpretation to rule out thyroid or should I seek a second opinion? Thank you for your answer.
1. I can't say for certain without knowing the normal range in your doctor's assay, but it looks to me like your TSH is normal. This means your thyroid is making a normal amount of thyroid hormone. The symptoms of hypothyroidism are very non-specific.
Lots of people with perfectly normal thyroid glands have problems with weight gain and fatigue. Swelling of the face and hoarseness of the voice only happen in extremely severe hypothyroidism, so the normal TSH also tells me that your facial swelling and hoarseness are not from the thyroid. High cortisol levels can certainly cause swelling of the face. I think you should continue to work with your endocrinologist to find out the significance of your elevated urinary cortisol. Since your thyroid levels are normal, your hoarseness is likely to be related to problems with your vocal cords. An Ear, Nose, and Throat doctor is the right person to look into this.
2. Autoimmune thyroid disease can be indicated by the presence of anti-thyroglobulin antibodies, anti-thyroid peroxidase antibodies, or both. The fact that your anti-thyroglobulin antibody level is positive means that there is a risk that some day you will eventually develop hypothyroidism. However, you are not hypothyroid now, so all that needs to be done is that your doctor should periodically recheck your TSH (perhaps once a year) to see if you are developing hypothyroidism. About 10% of normal adults have anti-thyroglobulin antibodies, and 15% or more of women over age 60 have them, so your condition is fairly common.
3. An enlarged or underfunctioning thyroid would not cause an increased cortisol. There is no connection between your high cortisol level and your positive anti-thyroglobulin antibodies. High cortisol levels are not related to thyroid disease.
4. Your childhood sarcoidosis has nothing to do with either your high urinary cortisol or your positive anti-thyroglobulin antibodies.
5. Very high cortisol levels can decrease the TSH, but would not increase it. Thyroglobulin antibodies interfere with the measurement of thyroglobulin, but they do not interfere with the measurement of TSH.
6. I don't think you need a second opinion at this time. I think you should repeat the urinary cortisol test as your endocrinologist has recommended.
Thomas A Murphy, MD, FACP, FACE
Associate Professor of Medicine
School of Medicine
Case Western Reserve University