Total and regional bone mineral content in women treated with GnRH agonists.

Changes in bone mineral content induced by GnRH agonists were investigated by measuring total body bone mineral content (TBBM) and regional bone mineral content (BMC) (arms, legs, trunk, pelvis) and densities with dual energy X-ray absorptiometry in 25 premenopausal women before and after a 6-month treatment with gonadotropin-releasing hormone (GnRH) agonists. Biological markers of bone remodeling, estrogens, luteinizing hormone, and follicle-stimulating hormone were also measured. Weight and body mass index increased significantly after treatment (P < 0.05), and TBBM, corrected for weight (TBBM/W), decreased (P < 0.001). The changes in BMC that we observed ranged from +2.5% to -6.9%. The greatest decrease in regional BMC occurred in the trunk (4.4%, P < 0.001), with TBBM decreasing by 2.1% (P < 0.001). No significant changes were observed in the limbs. Tartrate-resistant acid phosphatase (TRAP) increased significantly after treatment (P < 0.001) and a significant negative correlation between TRAP and TBBM (P < 0.001) and between TRAP and estradiol (P < 0.001) were observed before treatment. The lack of changes observed in the BMC of the limbs indicate that GnRH agonists cause a preferential loss of BMC in trunk osseous structures, a situation similar to that of the first years of menopause.

Total body bone mineral and tartrate-resistant acid phosphatase levels in type I and III osteogenesis imperfecta.

Serum tartrate-resistant acid phosphatase (TRAP) and total body bone mineral content (TBBM) were determined in a group of 16 children with osteogenesis imperfecta (OI) aged 5-14 years, 9 of whom suffered from type I and 7 from type III OI. TRAP and TBBM were also determined in a group of 26 normal children of a similar age range. TRAP levels were reduced in the type I and III OI groups (p less than 0.001). TBBM levels were lower in type I OI than in type III (p less than 0.005), and both OI groups showed reduced levels compared to the controls (p less than 0.001). The control group subjects showed a significant correlation between TRAP and TBBM (r = -0.62; p less than 0.001) which was not observed in the OI groups. Since TRAP is a biological marker of bone turnover, the results suggest that bone turnover is reduced in OI.

[Biological profile of tartrate-resistant acid phosphatase as a marker of bone resorption]. / Perfil biológico de la fosfatasa ácida tartrato resistente como marcador de la resorción ósea.

Tartrate-resistant serum acid phosphatase was measured in 123 subjects, 80 of which were normal and the rest pathologic, in order to define the profile and value of this parameter as a biological marker of osteoclastic activity. Normal subjects were divided into age groups based on the period where skeletal growth ends (under 20 years), at the age of menopause in women (50 years, between 20 and 50 years) and those over 50 years. There was an increase in tartrate-resistant serum acid phosphatase coinciding with puberty and no sex differences were observed after the 50 year mark, when women showed higher values than men (p less than 0.001). Such tartrate-resistant serum acid phosphatase increase, is reflected as higher values in the 50 year group than in the 20 to 50 year group (p less than 0.001), the only age limit where a negative significant correlation between tartrate-resistant serum acid phosphatase values and age could be observed (p less than 0.05). Values were higher up to the age of 20 years (p less than 0.001) than in any other older age group. Levels increased significantly (p less than 0.001 for both groups) in post-menopausal osteoporosis (n = 20) and in Paget's disease of bone (n = 15), and decreased significantly (p less than 0.05) in imperfect osteogenesis (n = 8), thus revealing its value as a biological marker of osteoclastic activity.