Introduction

Arthritis refers to inflammation of the joint. There are various forms, including rheumatoid arthritis, an autoimmune disorder that affects primarily young women. Osteoarthritis (OA) is a disorder caused by the wear and tear of joint due to the natural results of aging. OA characteristically affects middle age and elderly populations. 

Over 40 million American have some form of OA, including 80% of those over 50. The disease is more common in men under age 45 and in women over age 45.

This Research Brief examines the current medical thinking on this common and debilitating disease and explores alternative strategies for alleviating osteoarthritis.


Primer on Osteoarthritis (OA)

Osteoarthritis (also known as degenerative joint disease) is the localized degeneration of joint cartilage. It affects mainly the weight-bearing joints (e.g. knee, hip, spine). OA results from the repetitive use of the joints resulting in wear and tear, and from the normal results of aging without precise etiology. This is called primary OA. Secondary OA, on the other hand, could be the result of many factors such as sports injuries, inherited abnormalities in joint structure, continuous repetitive use over a long period of time, trauma, previous inflammatory disease of joints, etc.

OA is caused by the breakdown in the cellular processes that manufacture, maintain, and repair cartilage. Cartilage covers the ends of our bones. It is present in our joints and contains chondrocytes. Chondrocytes manufacture proteins known as proteoglycans that consist of chondroitin and keratin sulfate that are strung on core proteins. The proteoglycans hold joint fluid within the joint and, in conjunction with the joint cartilage, acts as a shock absorber for the body. Repetitive stress or trauma destroys the proteoglycans and collagen matrix (known as glycosaminoglycans (GAG), and inhibit the production of these substances by chondrocytes. This is how OA starts.

OA causes achy pain in the joints, leading to limitation of movement and loss of dexterity. Over time, osteoarthritic joints enter a vicious cycle of progressive deterioration, as the afflicted person tends to use the affected joints less due to pain. Symptoms generally begin in middle age, and by age 60, most people have some degree of OA. Diagnosis is primarily through a thorough history, physical examination, and x-ray findings, although the correlation is not accurate. About 40% of people with the worst x-ray classification for OA are pain-free. There is currently no reliable predictive marker for OA.


Anti-Arthritic Drugs

Modern medicine treats OA with 3 types of drugs:

1. Pain relievers, like aspirin, that primarily act to relieve symptoms of pain.
2. Non-steroidal anti-inflammatory drugs (NSAIDs), like ibuprofen (Motrin?, which focus on the relief of symptomatic pain with anti-inflammatory action.
3. Steroidal anti-inflammatory drugs. While these work wonders to provide short to medium-term relief, steroids are not recommended for long-term use.

Side Effects of Drugs

While drugs do help to relieve symptoms of OA, they have numerous adverse side effects, from relatively minor gastric upset, dizziness, and headaches, to severe gastric bleeding and interference with platelet function.

In addition, virtually all drugs used to treat OA have destructive effects on the articular cartilage lining the bones that form the joint that the drug is supposed to help. 

Analgesics, like aspirin, inhibit enzymes involved in the early stages of chondroitin sulfate biosynthesis. NSAIDs suppress proteoglycan synthesis by the chondrocyte. The depletion of chondrocytes further weakens the joint and exposes it to a faster deterioration cycle. Experimental studies show that these drugs inhibit cartilage synthesis and accelerate cartilage destruction. Steroids are the most effective anti-inflammatory agent. However, they can also cause extensive damage to chondrocytes in long-term use. In addition, chronic use of strong steroids leads to conditions that mimic Cushing's Syndrome, with a number of adverse age-accelerating consequences. 

Simply put, most drugs appear to suppress the symptoms, but accelerate the progression, of OA.