Biomarks in secondary osteoporosis.

Abstract

The existence of a metabolic disease in rheumatoid arthritis in distant zones of the active synovitis areas, remains controversial. Indeed, the variations found, by different authors, in PTH, in alkaline phosphatase and in serum and/or in the calcium urinary values, as well as in phosphate and hydroxyproline, have not clarified this problem, despite the demonstration by histomorphometry and by densitometrical methods, of a greater loss of the bone mass in rheumatoid arthritis. At the same time, metabolic changes in sexual hormones, primary or secondary, can modulate the immune response and interfere in the clinic expression of rheumatoid arthritis and also in the bone turnover. Therefore, the purpose of this study was to compare some parameters of the bone metabolism and of the hormonal condition, in women with rheumatoid arthritis, with and without corticotherapy and in an age-related control group. In Group RA (patients), we found relatively higher levels of phosphates, alkaline phosphatase and osteocalcin, just as in the nephrogenic c'AMP and the hydroxyproline/creatinine quotient. The blood levels of calcitonin, PTH, T3, T4, cortisol and estradiol did not show significant differences between the 2 groups, although they were lower in Group RA. On the contrary, the plasma levels of testosterone, of 4-androstenedione and DHEA.S were significantly reduced in patients with rheumatoid arthritis. These results are compatible with the existence of bone metabolic hyperactivity in rheumatoid arthritis, which can be related, directly or indirectly to the reduced androgens plasma levels, since these seem to play a protective role in auto-immune diseases and also on the bone metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)