Serum interleukin-6, soluble interleukin-6 receptor and soluble gp130 exhibit different patterns of age- and menopause-related changes

Growing evidence suggests that interleukin-6 (IL-6) may play a pathogenetic role in postmenopausal bone loss and in other age-related pathological conditions. In this study, we have examined the age-related changes in the serum levels of IL-6 and the soluble receptors that modulate its biological activity - soluble IL-6 receptor( sIL-6R) and soluble gp 130 (sgp 130) - in 220 women (from 25 to 104 yr old), including 22 centenarians. Serum IL-6 rose exponentially with age (r = 0.74, p < 0.0001). The median level of IL-6 increased almost ten-fold with age, from 1.16 pg/ml in premenopausal women to 10.27 pg/ml in centenarians. Serum sIL-6R and sgp 130 showed an increase until the seventh decade and a progressive decrease in older ages (r = 0.39, p < 0.0001 and r = 0.26, p = 0.008, respectively). IL-6, sIL-6R and sgp 130 were significantly higher in women within 10 yr of menopause as compared to premenopausal subjects (1.51 vs. 1.16 pg/ml, p = 0.012; 41.9 vs. 35.7 ng/ml, p = 0.002: and 253.4 vs. 230.7 ng/ml, p = 0.008, respectively). In postmenopausal women, a negative correlation was found between sIL-6R and the lumbar bone mineral density (BMD) (r = -0.28, p = 0.002) even after adjusting for age and weight. Furthermore, sIL-6R levels were higher in osteoporotic compared to normal women (47.9 vs. 39.5 ng/ml, p = 0.001). In conclusion, our results show that the serum levels of IL-6, sIL-6R and sgp 130 exhibit different patterns of age- and menopause-related changes, and that the biological activity of IL-6 may be increased with age with potential implications in the age-related diseases such as osteoporosis. (C) 2001 Elsevier Science Inc. All rights: reserved.