title: Hypothyroid myopathy: A peculiar clinical presentation of thyroid failure. Review of the literature.
abstract: Abnormalities in thyroid function are common endocrine disorders that affect 5-10 % of the general population, with hypothyroidism occurring more frequently than hyperthyroidism. Clinical symptoms and signs are often nonspecific, particularly in hypothyroidism. Muscular symptoms (stiffness, myalgias, cramps, easy fatigability) are mentioned by the majority of patients with frank hypothyroidism. Often underestimated is the fact that muscle symptoms may represent the predominant or the only clinical manifestation of hypothyroidism, raising the issue of a differential diagnosis with other causes of myopathy, which sometimes can be difficult. Elevated serum creatine kinase, which not necessarily correlates with the severity of the myopathic symptoms, is certainly suggestive of muscle impairment, though it does not explain the cause. Rare muscular manifestations, associated with hypothyroidism, are rhabdomyolysis, acute compartment syndrome, Hoffman's syndrome and Kocher-Debré-Sémélaigne syndrome. Though the pathogenesis of hypothyroid myopathy is not entirely known, proposed mechanisms include altered glycogenolytic and oxidative metabolism, altered expression of contractile proteins, and neuro-mediated damage. Correlation studies of haplotype, muscle gene expression and protein characterization, could help understanding the pathophysiological mechanisms of this myopathic presentation of hypothyroidism.
authors.affiliation: Department of Biomedical and Dental Sciences and of Morphological and Functional Images, University of Messina, Messina, Italy. alessandrosindoni@alice.it.|Dipartimento di Scienze Biomediche, Odontoiatriche e delle Immagini Morfologiche e Funzionali, Università degli Studi di Messina, Via Consolare Valeria, 1, 98125, Messina, Italy. alessandrosindoni@alice.it.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Sindoni
authors.affiliation: Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy.
authors.forename: Carmelo
authors.initials: C
authors.lastname: Rodolico
authors.affiliation: Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy.
authors.forename: Maria Angela
authors.initials: MA
authors.lastname: Pappalardo
authors.affiliation: IRCCS Centro Neurolesi "Bonino Pulejo", SS 113, Via Palermo, c.da Casazza, Messina, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Portaro
authors.affiliation: Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy.|Master Program on Childhood, Adolescent and Women's Endocrine Health, Messina, Italy.|Interdepartmental Program of Clinical and Molecular Endocrinology & Women's Endocrine Health, A.O.U. Policlinico "G. Martino", Messina, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Benvenga
mesh_terms: D000818:Animals; D003409:Congenital Hypothyroidism / Q000378:metabolism / Q000473:pathology; D006801:Humans; D006984:Hypertrophy / Q000378:metabolism / Q000473:pathology; D007037:Hypothyroidism / Q000378:metabolism / Q000473:pathology*; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology; D009135:Muscular Diseases / Q000378:metabolism / Q000473:pathology*; D012206:Rhabdomyolysis / Q000378:metabolism / Q000473:pathology; D013961:Thyroid Gland / Q000378:metabolism / Q000473:pathology*
keywords: Creatine kinase; Hoffmann’s syndrome; Hypothyroidism; Koche– Debre’–Semelaigne syndrome; Myalgia; Rhabdomyolysis