Study of Serum Irisin in patients with Thyroid Dysfunction

Abstract

Irisin, identified as a proteolytic cleavage product of the fibronectin type III domain-containing protein 5 (FNDC5), is a novel myokine secreted by contracting skeletal muscle, possibly mediating some exercise health benefits via ‘browning’ of white adipose tissue. Irisin can causes a significant increase in total body energy expenditure and resistance to obesity-associated insulin resistance in mice, while controversy still exists concerning irisin origin, regulation and function in humans (Yang et al., 2015). Both hypothyroidism and hyperthyroidism may cause signs and symptoms of neuromuscular dysfunction. Hypothyroidism has been associated with the clinical features of myopathy (for example, proximal muscle weakness) mononeuropathy, and sensorimotor axonal polyneuropathy. Hyperthyroidism may cause myopathy and possibly also polyneuropathy. The reported prevalence of these signs and symptoms is variable. In hyperthyroid patients 67% had neuromuscular symptoms, 62% had clinical weakness in at least one muscle group that correlated with FT4 concentrations (Duffy et al., 2000). Aim of our study was to study relation of thyroid status (hypo, hyperthyroid) with serum irisin, ck and peripheral neuropathy.