[Osteoporosis in collagen diseases].

The pathogenesis of osteoporosis in patients with rheumatic diseases, especially rheumatoid arthritis (RA), is poorly understood. The duration of the disease, the severity of the inflammatory process, gender, age, steroid therapy and menopause have been suggested as risk factors for osteoporosis in patients with RA. Although these factors may contribute to the development of osteoporosis, the influence of one specific factor is difficult to evaluate. It is said that the treatment with steroids has a deleterious effect on bone turnover, but this effect has been controversial. The dose margin of prednisone that will lead to osteoporosis is not known but has been estimated to be 10 mg per day. Fractures and stress fractures in patients with RA are probably much more common. Further study concerning osteoporosis in rheumatic diseases is necessary.