Age-Related Changes in the Musculoskeletal System and the Development of Osteoarthritis

Abstract

Synopsis Osteoarthritis (OA) is the most common cause of chronic disability in older adults. Although classically considered a “wear and tear” degenerative condition of articular joints, recent studies have demonstrated an inflammatory component to OA that includes increased activity of a number of cytokines and chemokines in joint tissues which drive production of matrix degrading enzymes. Rather than directly causing OA, aging changes in the musculoskeletal system contribute to the development of OA by making the joint more susceptible to the effects of other OA risk factors that include abnormal biomechanics, joint injury, genetics, and obesity. Age-related sarcopenia and increased bone turnover may also contribute to the development of OA. Understanding the basic mechanisms by which aging affects joint tissues should provide new targets for slowing or preventing the development of OA.

An update on the pathophysiology of osteoarthritis

“…In this framework "chondrosenescence" is intimately linked with obesity, lifestyle choices and inflammaging and at the molecular level with the disturbed interplay between autophagy and inflammasomes, thus contributing to the age-related increase in the prevalence of OA and a decrease in the efficacy of articular cartilage repair (47). Understanding "chondrosenescence" and the basic mechanisms by which aging affects articular cartilage and other joint tissues should reveal new therapeutic targets for slowing or preventing the development of OA (42). 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 Annals of Physical and Rehabilitation Medicine Special Issue: Osteoarthritis…”

Biological Markers Associated Osteoarthritis

“…Increase in ROS level is related to aging process and plays an important role in the progression of OA. There are various increasing inflammatory cytokines in OA such as IL-1, IL-6 and TNF-α, which encourage production of ROS as a result of increased level of MMPs (Loeser 2009;Loeser 2010).…”

“…On the anabolic process, the synthesis of extracellular matrix is stimulated by insulin-like growth factor (IGF)-1, transforming growth factor (TGF)-b, fibroblast growth factors (FGFs) and bone morphogenetic proteins (BMPs) (Aigner et al 2001). From the catabolic process, Matrix metalloproteinase (MMP) is increased and produced the inflammatory cytokines including interleukin (IL)-1, IL-17 and IL-18 and tumor necrosis factor (TNF)-a, which leads to decrease of aggrecan and matrix components, as a result of cartilage matrix degradation (Afonso et al 2007;Blanco et al 1998;Loeser 2010).…”

“…Age is the most important risk factor of osteoarthritis and the relationship between aging and OA is well known but the mechanisms are still not fully understood (Loeser 2010). At the cell and tissue level, articular cartilage consist of few cells and highly surrounding extracellular matrix (ECM).…”

AFM investigation of hyaline cartilage’s surface destruction

“…Osteoarthritis is a chronic, progressive disease which is characterized by an imbalance between the anabolic and catabolic processes in joint tissue [1]. Symptoms of osteoarthritis include the following: deep, achy joint pain exacerbated by extensive use, reduced range of motion and crepitus, frequently present, stiffness during rest [2].…”