letter: is glucosamine/chondroitin sulfate effective in the long-term on the progression of structural changes in knee osteoarthritis?

To the editor, osteoarthritis (oa) is the most common and disabling disease on the autonomy of older people and it affects the quality of life in the over 70 years population. oa has no cure and becomes an important problem of public health. the main goals are to ameliorate pain, inflammation and rigidity, and to diminish articular damage and joint destruction. glucosamine and chondroitin sulfate (g/cs) have proven symptomatic slow acting effects on the knee oa; however, its disease modifying drug effect for oa is controversial. to demonstrate the disease modifying effect (slowing/reversal of oa progression), it is necessary to perform prospective studies in long periods of time, ideally 1-2 years or more.