Advertisement
AJM online Clinical communication to the editor| Volume 128, ISSUE 6, e7-e8, June 2015

Download started.

Ok

Exertion-related Rhabdomyolysis Observed with Hyperthyroidism

Published:December 29, 2014DOI:https://doi.org/10.1016/j.amjmed.2014.12.012
      To the Editor:
      Rhabdomyolysis is a syndrome characterized by skeletal muscle breakdown resulting in the leakage of intracellular contents into circulation.
      • Sauret J.M.
      • Marinides G.
      • Wang G.K.
      Rhabdomyolysis.
      Although there are multiple etiologies, common causes of rhabdomyolysis include trauma, muscle disease, prolonged immobility, and certain medications.
      • Sauret J.M.
      • Marinides G.
      • Wang G.K.
      Rhabdomyolysis.
      Other causative factors are muscular overexertion and metabolic disorders, such as hypothyroidism.
      • Sauret J.M.
      • Marinides G.
      • Wang G.K.
      Rhabdomyolysis.
      This condition has been rarely associated with hyperthyroidism. Here, we report a case of exertion-induced rhabdomyolysis in a patient with untreated Graves' disease.

      Case Report

      A 42-year-old Caucasian woman presented to our practice for evaluation of muscle disease, as she had two previously confounding episodes of rhabdomyolysis. Five years prior, she had developed rhabdomyolysis after an intense arm workout. Then, the previous year, she noted extensive edema in both thighs hours after riding a mechanical bull. She denied trauma, and had no history of substance or statin use. On admission, she had a significantly elevated creatinine phosphokinase with normal troponin level. After evaluation at a specialty center, myositis was ruled out.
      Before this hospitalization, thyroid function tests showed a subclinical hyperthyroidism. One year following the second episode, imaging revealed elevated thyroid uptake values consistent with hyperthyroidism and a heterogeneous and hypervascular thyroid gland, as seen in thyroiditis. Her endocrinologist then initiated methimazole for Graves' disease. We suspected that she likely had long-standing thyroid dysfunction due to her history of unintentional weight and hair loss, and low thyroid-stimulating hormone levels (Table).
      TableCreatinine Phosphokinase and Thyroid Function Test Results Over Time
      DateCPK

      (11-166 IU/L)
      TSH

      (0.300-5.000 uIU/mL)
      Free T4

      (0.58-1.64 NG/dL)
      Free T3

      (2.20-4.10 PG/mL)
      10/20120.024
      03/201372,726
      03/201365,600
      05/2014330.0132.165.68
      05/20140.0271.344.38
      06/20140.0291.794.41
      CPK = creatinine phosphokinase; TSH = thyroid-stimulating hormone.
      During our visit, the patient had a negative review of systems, except for chronic neck pain and a “lump in my throat.” She was thin and well appearing. At 155 cm tall, her weight was 44.2 kg, with body mass index 18.4. Her blood pressure was 86/60 mm Hg. There was no exophthalmos, but positive thyromegaly. No notable physical examination findings or evidence of inflammatory myositis were present. Despite an unremarkable family history, a concomitant genetic abnormality affecting skeletal muscle was a possibility. On the basis of a rarely identified relationship, her tendency to develop rhabdomyolysis could have been related to muscular exertion coinciding with an underlying hyperthyroidism. We reasoned that treating the thyroid disease might reduce the risk of recurring events.

      Discussion

      There have been eight cases documenting rhabdomyolysis associated with thyrotoxicosis or thyroid storm. Of these cases, two describe rhabdomyolysis after routine exercise with undiagnosed hyperthyroidism.
      • Kim H.R.
      • Kim S.H.
      • Oh D.J.
      Rhabdomyolysis after a regular exercise session in a patient with Graves' disease.
      • Summachiwakij S.
      • Sachmechi I.
      Rhabdomyolysis induced by nonstrenuous exercise in a patient with Graves' disease.
      Kim et al
      • Kim H.R.
      • Kim S.H.
      • Oh D.J.
      Rhabdomyolysis after a regular exercise session in a patient with Graves' disease.
      reported a 23-year-old man who presented with flank pain after a weight-lifting session and was found to have Graves' disease without thyroid crisis. Summachiwakij and Sachmechi
      • Summachiwakij S.
      • Sachmechi I.
      Rhabdomyolysis induced by nonstrenuous exercise in a patient with Graves' disease.
      reported a 33-year-old man who presented with pain and stiffness in both thighs after nonstrenuous squatting and, on evaluation, also had Graves' disease. Ours is the third case of rhabdomyolysis observed in relation to physical exertion in untreated Graves' disease. It has been suggested that increases in cellular metabolism from hyperthyroidism could exhaust muscle energy stores, resulting in tissue damage.
      • Bennett W.R.
      • Huston D.P.
      Rhabdomyolysis in thyroid storm.
      Further investigation is needed. In conclusion, when rhabdomyolysis takes active patients for “a ride,” consider an underlying hyperthyroidism.

      Acknowledgment

      Thank you to Maria Martinez-Lage, MD at the University of Pennsylvania.

      References

        • Sauret J.M.
        • Marinides G.
        • Wang G.K.
        Rhabdomyolysis.
        Am Fam Physician. 2002; 65: 907-912
        • Kim H.R.
        • Kim S.H.
        • Oh D.J.
        Rhabdomyolysis after a regular exercise session in a patient with Graves' disease.
        Nephrology. 2012; 17: 307-308
        • Summachiwakij S.
        • Sachmechi I.
        Rhabdomyolysis induced by nonstrenuous exercise in a patient with Graves' disease.
        Case Rep Endocrinol. 2014; 2014: 286450
        • Bennett W.R.
        • Huston D.P.
        Rhabdomyolysis in thyroid storm.
        Am J Med. 1984; 77: 733-735