Thyroid Hormones Play Role in Sarcopenia and Myopathies

Abstract

Skeletal muscle maintains posture and enables movement by converting chemical energy into mechanical energy, further contributing to basal energy metabolism. Thyroid hormones (thyroxine, or T4, and triiodothyronine, or T3) participate in contractile function, metabolic processes, myogenesis and regeneration of skeletal muscle. T3 classically modulates gene expression after binding to thyroid hormone nuclear receptors. Thyroid hormone effects depend on nuclear receptor occupancy, which is directly related to intracellular T3 levels. Sarcolemmal thyroid hormone levels are regulated by their transport across the plasma membrane by specific transporters, as well as by the action of deiodinases types 2 and 3, which can activate or inactivate T4 and T3. Thyroid hormone level oscillations have been associated with the worsening of many myopathies such as myasthenia gravis, Duchenne muscular dystrophy (DMD) and rhabdomyolysis. During aging skeletal muscle show a decrease in mass and quality, known as sarcopenia. There is increasing evidence that thyroid hormones could have a role in the sarcopenic process. Therefore, in this review, we aim to discuss the main effects of thyroid hormones in skeletal muscular aging processes and myopathy-related pathologies.

Characterization of Skeletal Muscle Endocrine Control in an In Vitro Model of Myogenesis

“…The thyroid hormone plays an essential role in myogenesis; it acts as a pleiotropic factor during development and regulates genes involved in growth and differentiation [34,35]. In particular, data on C2C12 cells and primary myoblasts from mice have suggested the essential role of TRα in the optimal fusion and regeneration of myofibers after muscle injury and to maintain the SC niche during aging [36,37].…”

Hyponatremia associated with hypopituitarism in empty sella syndrome

“…En pacientes con hipotiroidismo, los niveles de CK descienden después de la terapia de reemplazo de T4 tal como ocurrió con nuestra paciente. Las estadísticas indican que la miopatía tiroidea por hipotiroidismo secundario es relativamente bajo pues (8).…”

Analysis of thyroid hormones and sarcopenia: association of creatine kinase and thyroid hormones (thyroid‐stimulating hormone, triiodothyronine, and free thyroxine): a cross‐sectional study

“…The consequences can lead to accidental falls, fractures, higher rates of hospitalization, and even death. The causes of sarcopenia are believed to include inadequate muscle use, hormonal changes, chronic diseases, insulin resistance, and nutritional deficiencies 4 …”