Abstract
Because endothelins (ET) have effects on functions of both osteoblasts and osteoclasts, it is thought that these peptides may be one of the mediators of coupling phenomena that maintain the connection and regulation between bone formation and resorption process in osteogenesis. Along with their demonstrated effects on osteogenic cells they have dual activity on both mineralization and resorption process. So it is also thought that they may have a major role in bone turnover and remodeling processes. We aimed to investigate if ET had a role in the pathophysiology of osteoporosis. Therefore we looked for a difference in ET plasma levels between osteoporotic and normal people.
86 patients (16 men and 70 women) with a mean age of 62.6 (ranges: 51–90) years were included in this study. All patients were examined by dual energy X-ray absorbsiometry evaluation at first. Patients were divided into 3 groups regarding reported T scores. T-scores less than −2.5 on either total lumbar spine or total hip were accepted as osteoporosis, while scores between −1 and −2.5 were accepted as osteopenia and scores above −1 were accepted as normal according to the suggestions of World Health Organization. According to these criteria 19 patients were normal, 43 were osteopenic and 24 were osteoporotic. Then total plasma level of ET was measured in all patients with monoclonal antibody based sandwich immunoassay (EIA) method.
One-way analysis of variance test was used to compare endothelin values between normals, osteopenics and osteoporotics regardless of gender and for each gender. A value of p< 0.05 was considered as significant.
Endothelin total plasma level in patients with osteoporosis was a mean of 98.3663.96 pg/ml, a mean of 100.9247.2 pg/ml in osteopenic group and a mean of 99.5656.6 pg/ml in normal group. The difference between groups was not significant (p> 0.05). In men with osteoporosis endothelin level was a mean of 185.7017.2 pg/ml and this was significantly higher than osteopenic men (124.8059.6 pg/ml) (p< 0.05) and normal men (93.0050.1pg/ml) (p< 0.05). In women there was not any significant difference between groups (normal:102.0060.7pg/ml, osteopenics: 94.7042.7pg/ml, osteoporotics: 79.9053.8pg/ml) (p> 0.05).
We found out that plasma ET levels of osteoporotic men were significantly higher than normal men. But comparison regardless of gender among osteoporotics, osteopenics and normals and comparison of female osteoporotics, osteopenics and normals yielded no significant differences. We think that the reason for differences in our results regarding gender may be the higher estrogen level of the females even if they were in the postmenopausal period and thus estrogens’ possible effect of down regulation in ET-1. Considering these results we think that ET may have a role in the pathophysiology of the men osteoporosis and it can be used as a marker for diagnosis and treatment follow-up of osteoporosis.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
