The Effect of Glycation Stress on Skeletal Muscle

*Tatsuro Egawa, Kohei Kido, Takumi Yokokawa, Mami Fujibayashi, Katsumasa Goto and Tatsuya Hayashi*

#### **Abstract**

Glycation stress (glycative stress) is a general concept of biological stress caused by a series of non-enzymatic glycation reactions, including advanced glycation end products (AGEs) formation, AGEs accumulation, glycation-associated dysfunction of proteins and cellular signaling, inflammation, oxidation, and/or tissue damage. There has been increasing evidence supporting a profound effect of AGEs on human diseases such as type 2 diabetes, cardiovascular disease, cancer, Alzheimer's disease, osteoporosis, and dementia, as well as aging process itself. In addition, dietary AGEs intake has also been suggested to contribute to tissue dysfunction and development of the diseases. Skeletal muscle is the largest organ in the human body and important responsibility for maintaining our health as not only locomotor system but also metabolic and endocrine systems. Especially in past decades, numerous studies have suggested the contribution of glycation stress to skeletal muscle dysfunctions (e.g. muscle atrophy, reducing contractile property, and insulin resistance). In this chapter, we provide current evidence on the potential role of glycation stress in the impairment of skeletal muscle functions.

**Keywords:** glycative stress, skeletal muscle dysfunction, skeletal muscle atrophy, advanced glycation end products, AGEs

#### **1. Introduction**

Skeletal muscle is the largest organ in the human body, accounting for approximately 40% of body weight. A primary characteristic of skeletal muscle is its ability to contract and cause movement. In addition, skeletal muscle is a metabolic organ of high metabolic activity regarding nutrient (glucose, lipid, and protein) storage and supply. It has also recently been found that skeletal muscle is a secretary organ that produces and releases cytokines and other peptides, which is known as myokine, that function in manner similar to hormones [1]. Thus, skeletal muscle has an important responsibility for maintaining our health as not only locomotor system but also metabolic and endocrine systems [2]. After the age of 50, approximately 1–2% of muscle mass and 1.5–5% of muscle strength are lost per year [3]. These reductions in muscle mass, strength, and function, the so-called sarcopenia, link to numerous adverse consequences including frailty, disability, morbidity, and mortality [2].

Over the last few decades, there has been increasing evidence supporting a profound effect of advanced glycation end products (AGEs) on human diseases, including type 2 diabetes, cardiovascular disease, cancer, Alzheimer's disease, osteoporosis, and dementia, as well as the aging process itself [4, 5]. Especially in past decades, many epidemiological studies have suggested the contribution of glycation stress (also called as glycative stress) from AGEs to sarcopenia [6–17]. In this chapter, we provide current evidence on the potential role of glycation stress in the impairment of skeletal muscle functions.
