Associations of Markers of Inflammatory Status and Adiposity with Bone Phenotype at Age 60–64 Years: Findings from the MRC National Survey of Health and Development

This study investigated associations between markers of inflammatory status and adiposity (interleukin-6 [IL-6], adiponectin and leptin) and measures of bone phenotype and fractures. The Medical Research Council (MRC) National Survey of Health and Development (NSHD) is a British birth cohort study. Participants (born during the same week in 1946) with complete data on DXA and pQCT parameters, markers of inflammatory status and adiposity, and potential confounders (498 men and 474 women) were included in cross-sectional analyses. At age 60-64 years, bone phenotype was assessed by DXA and pQCT. Fractures were self-reported at ages 60-64 and 68-70 years. Multiple linear regression was used to determine associations of IL-6, adiponectin and leptin with bone phenotype (adjusted for fat and lean mass and lifestyle confounders). Standard deviation (SD) differences in outcomes per SD increases in exposures were estimated. Higher IL-6 levels were associated with lower total volumetric bone mineral density (vBMD) (- 0.10[- 0.19, 0.00]) in men, and higher areal BMD (aBMD) at the spine (0.12[0.03, 0.22]) and whole body (0.11[0.01, 0.20]) in women. Higher levels of adiponectin were associated with lower aBMD and trabecular vBMD. In women, higher leptin levels were associated with higher cortical vBMD (0.11[0.02, 0.20]). Higher adiponectin was associated with moderately increased odds of having a fragility fracture during adulthood in women (OR 1.16 [95% CI 0.94, 1.43, p = 0.18]). Our results highlight non-mechanical associations between markers of inflammatory status and adiposity with BMD and, in women, fractures. Ensuring inflammaging is minimised may be important in healthy bone ageing.