Weight-adjusted waist index associated with bone mineral density in rheumatoid arthritis patients: a cross-sectional study

The research examined the association between weight-adjusted waist index (WWI) and bone mineral density (BMD) in individuals with rheumatoid arthritis, considering the impact of obesity on bone health. The association between WWI and BMD was examined utilizing weighted linear regression and smoothed curve fitting with data from NHANES 2005–2010, 2013–2014, and 2017–2018. Subgroup analysis verified the stability of the results. The study included a cohort of 983 rheumatoid arthritis patients. A significant negative correlation was found between WWI and BMD at the total femur, femoral neck, and lumbar spine (β = -0.03, 95% CI (-0.04, -0.02), p < 0.001; β = -0.02, 95% CI (-0.04, -0.01), p = 0.001; β = -0.04, 95% CI (-0.06, -0.02), p < 0.001). This negative association was not significantly influenced by factors like age, gender, race, education, PIR, diabetes, hypertension, sleep disorders, alcohol consumption, or smoking status (p > 0.05 for interaction). The findings indicate a negative correlation between WWI and BMD in the rheumatoid arthritis population.