THERE IS NO DIFFERENCE IN SPONTANEOUS AND 17-BETA-ESTRADIOL-INDUCED INTERLEUKIN-1-BETA RELEASE BY PERIPHERAL-BLOOD MONONUCLEAR-CELLS FROM NONOSTEOPOROTIC WOMEN WITH DIFFERENT RATES OF EARLY POSTMENOPAUSAL BONELOSS

Interleukin-1 (IL-1, is a potent stimulator of bone resorption, and a causal role for IL-1 has been suggested in postmenopausal bone loss. W e have examined IL-1 beta release in vitro by peripheral blood mononuc lear cells (PBMC) isolated from nonosteoporotic women 9-15 yr after me nopause. These women had presented 6 yr previously with significant di fferences in the rate of early postmenopausal bone loss. Ten women wit h low rates of bone loss (median 2.0% per year) and 10 women with high rates of bone loss (median 4.9% per year) were included in the study. The women with a high rate of bone loss had a significantly lower bon e mass of the lumbar vertebrae compared with that of the other group, but there were no differences in biochemical markers of bone metabolis m between the groups (pyridinoline/creatinine ratio in urine and colla gen 1 c-terminal telopeptide and bone gla protein in serum). Moreover, there was no difference in spontaneous IL-1 beta release by PBMCs bet ween the two groups and no correlation between IL-1 beta release and p resent bone turnover, as judged by biochemical markers. Treatment of P BMCs with 10 nmol/L 17 beta-estradiol in vitro significantly stimulate d IL-1 beta production in both groups. We conclude that IL-1 beta prod uction by PBMCs in vitro does not correlate with the rate of early pos tmenopausal bone loss.