| Objective To determine the associations between serum markers of inflammation and changes in bone mineral density (BMD) and urinary pyridinoline (PYR) to creatinine (Cr) ratio in older adults. Methods A total of 168 randomly selected subjects (mean age 63 years, range 52-78, 48% female) were studied. BMD was measured by dual-energy X-ray absorptiometry at baseline (mean T-score: -0.18 to -0.61) and 2.9 years later. Serum high-sensitivity C-reactive protein (hs-CRP), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), and the urinary PYR/Cr ratio were measured on both occasions. Results The mean annual loss of BMD was 0.15%, 0.15%, and 0.34% at total body, spine, and hip, respectively. Change in total body BMD was associated with baseline hs-CRP, IL-6 and TNF-α, as well as change in hs-CRP (β: -0.41%/U, 95% confidence interval -0.68%, -0.15%) and IL-6 (β: -0.62%/U, 95% confidence interval -1.01%,-0.23%). When these markers were put in the same predictive model, only IL-6 remained largely unchanged. Changes in other BMD sites were significantly predicted by IL-6 (hip and spine) and TNF-α (spine only). Finally, change in the PYR/Cr ratio was positively associated baseline IL-6, hs-CRP, and their changes (all P<0.05) in women, but not in men. Conclusions In this study, we found that changes in IL-6 were associated with decreased bone mineral density and bone resorption. |