Glucosamine, Chondroitin Sulphate and Equine Osteoarthritis
Recent research suggests that "supplemental glucosamine or chondroitin sulphate may help to prevent cartilage degeneration and treat OA (osteoarthritis)", according to lead researcher Prof. R Baccarin, DVM, PhD, professor of veterinary medicine at University Sao Paulo.
Osteoarthritis is a chronic condition in which there is progressive degeneration of one or more joints. Symptoms include joint swelling, pain, instability, restrictions in movement and functional impairment. In its mildest form OA will result in time off and reduced performance, and as the disease progresses, retirement in a performance horse as the joint becomes non functional. The disease progresses through a number of phases, characterised by an advancing loss of joint cartilage. Initially the cartilage tries to repair itself, but as the disease progresses the layer of bone beneath the joint cartilage hardens and the amount of space within the joint decreases. In the erosive phase bone cysts form (fluid filled abnormalities in the bone tissue) and the last phase involves remodelling of the bone itself.
Of all the tissues in the body, cartilage tissue contains the highest concentration of GAGs (Glucosaminoglycans), especially chondroitin sulphate and keratin sulphate. The research team used the level of GAGs in horse urine to study the effects of glucosamine and chondroitin sulphate on osteoarthritis. Firstly the urine of 20 healthy horses and 27 horses with mild OA was analysed. The results were that the OA horses excreted more urinary GAGs than the healthy horses. This suggests that in OA there is a higher turn-over of the components that go to make up joint cartilage, and that these are detectable in urine.
6 of the horses diagnosed with mild OA then underwent a treatment protocol using both Glucosamine and Chondroitin Sulphate.
"Upon treatment with CS+GlcN, there was a significant improvement in flexion test...There was also a decrease in joint volume, and the scores assigned to lameness and pain in different joints also improved".
The different chemical components of GAGs differs with age, but interestingly the chemical make-up of the GAGs from the OA horses, was closer to that of a young growing horse "suggesting that the cartilage is actively synthesizing extracellular matrix components of the 'growth and calcification' type, in an effort to regenerate itself".
The body wants to repair the damage associated with OA, and it would seem from this research, that in cases of mild OA at least, providing supplemental sources of glucosamine and chondroitin sulphate gives the body the building blocks it needs to do just that.
Review of the research paper "Urinary glycosaminoglycans in horse osteoarthritis. Effects of chondroitin sulphate and glucosamine. Baccarin. R.Y.A, Machado. T.S.L, Lopes-Mores. A.P, Vieira. F.A.C, Michelacci. Y.M.