<p>Circulatory pattern of cytokines, adipokines and bone markers in postmenopausal women with low BMD</p>

Abstract

Objective: In addition to some well-characterized bone turnover markers (BTMs), cytokines and adipokines have also been suggested to be linked to osteoporosis seen in menopause. However, there is much controversy on the possible association between these markers and bone mineral density (BMD). This study was aimed at measuring circulatory levels of selected cytokines, adipokines and BTMs in postmenopausal women with normal and low BMD. Methods: The study population included 71 post-menopausal women, of whom 25 had normal BMD, 31 had osteopenia and 13 had osteoporosis. Circulatory levels of selected pro-resorptive (TNF-α, IL-1β, IL-6, IL-8, IL-12, IL-17), anti-resorptive (IFN-γ, IL-4, IL-10, IL-13, TGF-β) and five adipokine markers (adiponectin, adipsin, lipocalin-2/NGAL, PAI-1 and resistin) were measured using the Multiplex system and read on the Magpix ELISA platform. Further, two bone turnover markers (PINP, CTX) as well as estradiol levels were assayed from the same samples. Results: While circulatory levels of cytokines were comparable between groups, women with low BMD had statistically significantly higher median circulatory levels of adipokines as compared to those with normal BMD. Further, while levels of CTX were not different between the two groups; PINP, PINP/CTX ratio and estradiol levels were significantly lower in women with low BMD. Levels of adiponectin, PINP, PINP/CTX ratio and estradiol correlated significantly with BMD of the hip and spine. Conclusion: The associations between various markers and BMD are complex and multivariate. Our data provide insights into the possible use of circulatory levels of cytokines, adipokines and bone turnover markers on the pathogenesis of postmenopausal osteoporosis because of the well-documented effects of these molecules on bone tissue and their relevance to osteoporosis.

Osteokines and Bone Markers at Rest and following Plyometric Exercise in Pre- and Postmenopausal Women

“…However, while CTXI was significantly higher in the postmenopausal group, PINP was not significantly different between groups. The higher PINP/CTXI ratio in the premenopausal group, although it did not reach significance, is consistent with a recent study reporting no differences in CTXI but significantly lower PINP/CTXI ratio in postmenopausal women with low bone mineral density compared to those with normal bone mineral density [ 9 ]. In addition, the significant correlation between the PINP/CTXI ratio and estrogen ( r = 0.58, p = 0.002) supports previous studies suggesting that the decline in circulating estrogen postmenopause leads to a negative change in the balance of bone remodeling [ 3 , 4 ].…”

“…PINP is a sensitive marker of dynamic changes in bone formation that reflects changes in new collagen synthesis, while CTXI is a sensitive marker of bone resorption reflecting the rate of collagen breakdown [ 8 ]. In addition, the PINP/CTXI ratio has been positively correlated with bone mineral density (BMD) of the hip and spine in postmenopausal women [ 9 ].…”

IL-33/IL-31 Axis in Osteoporosis

“…During aging, in addition to proinflammatory cytokines, the production of reactive oxygen species (ROS) is also increased. The expression of IL-31 in monocytes, dendritic cells, and T lymphocytes can be induced by ROS, enhancing the age-related bone resorption [61].…”

Resistance training decreases plasma levels of adipokines in postmenopausal women

“…increased 17 and the levels of adiponectin negatively correlated with bone mineral density, serum oestradiol concentration and monocyte chemotactic protein-1 18,19 . However, in postmenopausal women lower levels of adiponectin are found in obese and overweight patients as compared with healthy weight women 20 .…”