PDFQuestion
Dear Doctor I have a patient with benign thyroid cyst on suppressive therapy with 150 micrograms thyroxine . H e r thyroid function tests on this are : Free T 4 23.2pmol/l range10-25 freeT3 6.8pmol/l range 3.3-7.2 S-TSH <0.01 0.2-0.4 Her uric acid is very low at 86micromols/l, range 140-390. She also has a hip bursitis and shoulder capsulitis, but ESR is normal, RF normal, and ANF normal. Her diet is apparently normal. Using a MIRENA coil . Is there any relation of the low uric acid to the thyroid treatment
Regards,
Dr Tom Scade, MbChBBSC(Hons) FRCP(G) MRCGP(UK)
Emirates Clinic
PO Box 26777, Dubai
UAE
Response
There is no description that I can find of subnormal serum uric acid associated with thyroid hormone excess. There is a useful section on hypouricemia in the Harrison text, 14th Edn, p2165. Can you be sure that none of the medications used for the shoulder complaint have a uricosuric component ? One other comment. I wonder about the wisdom of using suppressive T4 therapy in a woman who may be at risk of osteoporosis, when the benefit of such therapy in managing benign cysts is less than convincing. Subclinical thyrotoxicosis as a result of suppressive T4 certainly seems to decrease bone density (see Wesche et al J Clin Endocrinol Metab 2001; 86:998-1005)
Regards,
Jim Stockigt