Introduction:
Obesity and aging are established independent risk factors for osteoarthritis (OA). This study aims to evaluate the correlation between the age-adjusted visceral adiposity index (AVAI) and OA.

Material and methods:
This study was a cross-sectional study on the data from the NHANES during the period from 1999 to 2018. The correlation between AVAI and the prevalence of OA was explored through receiver operating characteristic (ROC) regression, multivariate logistic regression, restricted cubic spline regression, and subgroup analysis.

Results:
The study cohort comprised 20,628 participants, of whom 2,297 (11.1%) were diagnosed as OA. An increase in the quartile range of AVAI was correlated with a significant rise in the prevalence of OA (1.5%vs.5.1% vs.14.4% vs.23.6%, p<0.001). Logistic regression analysis demonstrated a significantly positive correlation between AVAI and the risk of OA (OR=1.14, 95%CI: 1.06, 1.23). Subgroup analyses indicated that this correlation was more pronounced in individuals aged over 60 years old and those with diabetes. RCS regression analysis further identified a non-linear positive correlation, with an inflection point at -6.03. Finally, the area under the ROC curve (AUC) for AVAI was notably greater (AUC=0.757, 95% CI: 0.747, 0.766) compared to traditional obesity indices.

Conclusions:
This study is the first to demonstrate a significantly positive correlation between the prevalence of OA and AVAI, with AVAI exhibiting superior diagnostic performance over traditional obesity indices in identifying OA.