Relationship between diet-related inflammation and bone health under different levels of body mass index

BACKGROUND: Osteoporosis is a major public health problem. Dietary inflammatory preference and body mass index (BMI) are emerging factors that tends to affect bone health. There is limited evidence regarding the joint influence of BMI and dietary status on the bone health. This study aimed to investigate the relationship between dietary inflammatory index (DII) and bone health among adults under different levels of BMI utilizing the National Health and Nutrition Examination Survey (NHANES). METHODS: Data were collected from 2005–2010, 2013–2014 to 2017–2018 in NHANES. In total, 10,521 participants who aged ≥ 20 years and had complete data for dietary intake interview, bone mineral density (BMD) and bone mineral content (BMC) were included. DII was performed to evaluate the dietary inflammatory potential based on dietary intake interview. We evaluated bone health by femoral neck BMD and BMC measured by dual energy X-ray absorptiometry. Weighted multivariable linear regression and BMI-stratified subgroup analysis were performed. RESULTS: The average DII score for 10,521 participants was 1.24 ± 0.04, mean femoral neck BMD was 0.82 ± 0.00 g/cm(2) and mean BMC was 4.37 ± 0.01 g. In the fully adjusted model, there was a negative correlation between DII with BMD (β = − 0.016, P < 0.001) and BMC (β = − 0.011, P < 0.001) in the most anti-inflammatory diet. Using BMI-stratified subgroup analysis, this correlation became more evident in both the overweight (BMD: β = − 0.024, P < 0.001; BMC: β = − 0.058, P = 0.042) and obese groups (BMD: β = − 0.015, P = 0.049; BMC: β = − 0.009, P = 0.042), while this correlation was opposite in DII tertile 2 (middle DII score) in the underweight group (BMD: β = 0.047, P = 0.038; BMC: β = 0.274, P = 0.010). CONCLUSION: Relationship between higher consumption of pro-inflammatory and increased risk of lower BMD and BMC was only existed in overweight and obese participants.