Serum Irisin: Pathogenesis and Clinical Research in Cardiovascular Diseases

Abstract

Recently, muscular function/dysfunction has gained importance in the maintenance of metabolic homeostasis in cardiovascular diseases. Skeletal muscle plays a vital role in coordinating the activity and metabolism of endocrine organs by secreting many myokines, especially irisin. Irisin is a polypeptide hormone consisting of 112 amino acids secreted into the blood from muscle and adipose tissues. Serum irisin levels are associated with cardiometabolic risk factors such as obesity and insulin resistance as defined by homeostatic model assessment. Irisin reduces endothelial damage by inhibiting inflammation and oxidative stress, thus playing a key role in maintaining endothelial cell function. Unsurprisingly, low irisin levels cause endothelial dysfunction and increase the incidence of atherosclerosis. We aimed to summarize the studies on this issue since we have not found any review in the literature on the role of serum irisin levels in the process of atherosclerosis and other cardiovascular events in cardiovascular diseases.

Serum Irisin Levels, Endothelial Dysfunction, and Inflammation in Pediatric Patients with Type 2 Diabetes Mellitus and Metabolic Syndrome

“…Our results showed lower irisin levels in the group with MetS when compared with healthy controls, as well as an inverse association between the irisin concentration and BMI percentile, WC percentile, and weight. In agreement with our findings, decreased serum irisin levels in adults [ 32 ], children, and adolescents [ 37 , 38 , 56 ] have been reported. On the contrary, Jang et al described increased irisin levels in adolescents with MetS [ 36 ].…”

“…For instance, positive correlations between plasma irisin concentration and both triglyceride levels and the Homeostatic Model Assessment (HOMA) index were described in nondiabetic children [ 35 ] and adolescents with MetS [ 36 ]. On the contrary, lower serum irisin concentrations were shown in overweight and obese children with MetS compared with those without MetS [ 37 , 38 ]. Some authors have suggested that changes in the concentration of irisin might play a role in the pathogenesis of MetS [ 31 – 33 , 36 – 38 ].…”

“…On the contrary, lower serum irisin concentrations were shown in overweight and obese children with MetS compared with those without MetS [ 37 , 38 ]. Some authors have suggested that changes in the concentration of irisin might play a role in the pathogenesis of MetS [ 31 – 33 , 36 – 38 ]. Noteworthy, a study in pediatric patients with T2DM reported decreased levels of irisin when compared with healthy controls [ 39 ].…”

Irisin as a Novel Biomarker of Subclinical Atherosclerosis, Cardiovascular Risk and Severe Disease in Axial Spondyloarthritis

“…Importantly, abnormalities in a growing number of molecules mainly implicated in metabolic and inflammatory mechanisms also boost the atherosclerotic process, further promoting the increased CV morbidity in axSpA patients (9). In this regard, muscle and adipose tissue play a pivotal homeostatic function by producing a large number of these molecules, mainly myokines and adipokines, which exert autocrine, paracrine and/or endocrine effects, affecting multiple organs (10)(11)(12). Thereby, these molecules are implicated in the regulation of the immune response and in the pathogenesis of numerous chronic inflammatory diseases (13).…”

“…In this context, since its discovery in 2012, much attention has been paid to the adipomyokine irisin (14). This molecule has been reported to play a critical beneficial role in several processes such as inflammation, angiogenesis, oxidative stress, endothelial cell dysfunction, and lipid and bone metabolism (11)(12)(13)(14)(15)(16)(17)(18)(19). In particular, it has been described that irisin plays key roles against vascular inflammation by inhibiting the recruitment of inflammatory cells to the atherosclerotic lesions and also inducing the switch from the proinflammatory (M1) phenotype of macrophages to the antiinflammatory (M2) phenotype (19)(20)(21)(22)(23).…”