THYROTOXIC PERIODIC PARALYSIS IN A COMPETITIVE BODYBUILDER WITH THYROTOXICOSIS FACTITIA

Objective: We report a case of thyrotoxic periodic paralysis (TPP) in a bodybuilder who developed paralysis secondary to thyrotoxicosis factitia after taking a supplement containing thyroid hormone. Interestingly, the patient had no intrinsic thyroid disease. Prompt recognition of thyrotoxicosis is critical to avoid progression of paralysis and subsequent complications. Methods: We discuss a 27-year-old body builder who presented after a 3-day bodybuilding competition with sudden upper and lower extremity paralysis. He admitted to taking anabolic steroids, a supplement containing an unknown amount of thyroid hormone for 2 weeks, and furosemide 40 mg twice daily with near-complete fluid restriction for 3 days. Results: Laboratory results showed a thyroid-stimulating hormone (TSH) level of <0.010 μIU/mL (normal, 0.3 to 5.8 μIU/mL), normal total triiodothyronine level, elevated free thyroxine level of 3.6 ng/dL (normal, 0.8 to 1.9 ng/dL), and potassium level of 1.9 mEq/L (normal, 3.7 to 5.2 mEq/L). Thyroid peroxidase antibody, thyroid-stimulating immunoglobulin, and thyroglobulin antibody levels were normal. Thyroid uptake was 1% (normal, 8 to 25%) after administration of I-123 and thyroglobulin level was 9 ng/mL (normal, 1.4 to 29.2 ng/mL). The patient was treated with normal saline infusion, magnesium supplementation and a total of 230 mEq of potassium within 12 hours of hospitalization. Muscle weakness resolved within this time period and potassium level normalized. By the third day of hospitalization free thyroxine level also normalized and TSH improved to 0.1 mIU/L. Conclusion: TPP is a rare complication of thyrotoxicosis that should be considered in bodybuilders who are presenting with acute muscle weakness.

Euthyroid athyroxinemia – a novel endocrine syndrome

Summary A 55-year-old female was referred with abnormal thyroid function tests (TFTs); the free thyroxine level (FT4) was undetectable <3.3 pmol/L (normal: 7.9–14.4), while her FT3, TSH and urinary iodine levels were normal. She was clinically euthyroid with a large soft lobulated goitre that had been present for more than thirty years. She received an injection of recombinant human TSH (rhTSH) following which there was a progressive rise of the FT3 and TSH levels to 23 pmol/L and >100 mIU/L respectively at 24 h, The FT4 however remained undetectable throughout. Being on thyroxine 100 µg/day for one month, her FT4 level increased to 15 pmol/L and TSH fell to 0.08 mIU/L. Four years earlier at another hospital, her FT4 level had been low (6.8 pmol/L) with a normal TSH and a raised Tc-99 uptake of 20% (normal<4%). We checked the TFTs and Tc-99 scans in 3 of her children; one was completely normal and 2 had euthyroid with soft lobulated goitres. Their Tc-99 scan uptakes were raised at 17% and 15%, with normal TFTs apart from a low FT4 7.2 pmol/L in the son with the largest thyroid nodule. This is a previously unreported form of dyshormonogenesis in which, with time, patients gradually lose their ability to synthesize thyroxine (T4) but not triiodothyroxine (T3). Learning points: This is a previously unreported form of dyshormonogenetic goitre. This goitre progressively loses its ability to synthesize T4 but not T3. The inability to synthesize T4 was demonstrated by giving rhTSH.