Association of the Dietary Inflammatory Index with bone mineral density and osteoporosis among adults with type 2 diabetes

Dietary inflammatory load, quantified using the Dietary Inflammatory Index (DII), reflects pro-inflammatory dietary patterns that may contribute to impaired bone health. However, population-based evidence regarding the association between dietary inflammatory potential and bone mineral density (BMD) among adults with type 2 diabetes (T2D) remains limited, particularly regarding potential sex-specific differences. This cross-sectional study assessed the association between the DII and low BMD (osteopenia or osteoporosis) in adults with T2D. Data from the 2007 to 2010, 2013 to 2014, and 2017 to 2018 cycles of the National Health and Nutrition Examination Survey were analyzed. DII scores were computed from 22 dietary components; participants lacking BMD or DII data were excluded. Low BMD was defined from femoral neck and lumbar spine BMD, with osteoporosis and osteopenia both classified into a single category (“low BMD”). Weighted logistic regression was used to examine the relationship between DII score and low BMD overall and according to sex, adjusted for age, race/ethnicity, body mass index, socioeconomic variables, and clinical confounders. Subgroup analyses, interaction tests, and sex-stratified correlation analyses were performed for consistency. Data from 1768 adults with T2D, of whom 798 had low BMD, were included. Higher DII scores were significantly associated with an increased risk for low BMD in women (femoral neck: odds ratio = 2.575, 95% confidence interval = 1.484–4.468, P  = .001; lumbar spine: odds ratio = 1.864, 95% confidence interval = 1.111–3.129, P  = .018), with no significant association observed in men. A significant interaction according to sex was detected ( P for interaction = .02); however, no interactions were found for age or body mass index. Findings suggested that an elevated DII is independently associated with low BMD in women with T2D. Clinically, sex-specific, anti-inflammatory dietary strategies may help mitigate the risk for low BMD in this population.