Higher serum concentrations of dietary antioxidants are associated with lower levels of inflammatory biomarkers during the year after hip fracture

Abstract

Chronic inflammation impairs recovery among the 1.6 million people who suffer from hip fracture annually. Vitamin E and the carotenoids are two classes of dietary antioxidants with profound anti-inflammatory effects, and the goal of this study was to assess whether higher post-fracture concentrations of these antioxidants were associated with lower levels of interleukin 6 (IL-6) and the soluble receptor for tumor necrosis factor-alpha (sTNF-αR1), two common markers of inflammation. Serum concentrations of the dietary antioxidants and inflammatory markers were assessed at baseline and 2, 6, and 12 month follow-up visits among 148 hip fracture patients from The Baltimore Hip Studies. Generalized estimating equations modeled the relationship between baseline and time-varying antioxidant concentrations and inflammatory markers. Higher post-fracture concentrations of vitamin E and the carotenoids were associated with lower levels of inflammatory markers. Associations were strongest at baseline, particularly between the α-tocopherol form of vitamin E and sTNF-αR1 (p = 0.05) and total carotenoids and both sTNF-αR1(p = 0.01) and IL-6 (p = 0.05). Higher baseline and time-varying α-carotene and time-varying lutein concentrations were also associated with lower sTNF-αR1 at all post-fracture visits (p ≤ 0.05). These findings suggest that a clinical trial increasing post-fracture intake of vitamin E and the carotenoids may be warranted.