Use of crystalline glucosamine sulfate in osteoarthritis

Abstract

The pharmacological treatment of osteoarthritis is traditionally accomplished with nonspecific symptomatic agents, which are generally effective only for acute symptom relief. Compounds are under investigation that might exert specific effects on osteoarthritis pathogenesis and thus induce at least a similar short-term symptomatic effect, but also control disease progression in the long term. Glucosamine sulfate reverses the proinflammatory and joint-degenerating effects of interleukin-1 by inhibiting the cytokine intracellular signaling pathway. Clinical trials with the crystalline glucosamine sulfate formulation approved as a prescription drug, predominantly at the dose of 1500 mg once daily, demonstrated a specific symptom-modifying effect over short- and long-term treatment courses. Two 3-year trials suggested that the drug also has joint structure-modifying properties and, therefore, might be useful as a disease-modifying agent in osteoarthritis. However, efficacy data obtained with this prescription glucosamine sulfate formulation may not be applicable to all glucosamine products that are available as dietary supplements. Osteoarthritis is the most common form of arthritis and the most prevalent among rheumatic diseases. It is a degenerative joint disorder with minimal signs of inflammation, which may affect all diarthrodial joints and whose most appropriate definition combines a description of the pathology of the disease with pain that occurs with joint use [1]. Osteoarthritis is particularly frequent at the large, weight-bearing joints of the lower limbs. Radiographic osteoarthritic changes of the knee tibiofemoral compartment occur in 5–15% of the general population aged 35–74 years in the Western world [2]. Symptomatic knee disease occurs in approximately 6% of US adults over 30 years of age [3], with general incidence and prevalence increasing two- to tenfold from age 30 to 65 years [4]. The impact on disability attributable to knee osteoarthritis is similar to that due to cardiovascular disease and greater than that caused by any other medical condition in the elderly [5]. Treatment guidelines for knee and hip osteo