Relationship between three body obesity indicators, WWI, BMI, WtHR, and periodontitis

Many scholars have studied the relationship between obesity and periodontitis. The relationship between different obesity indicators and periodontitis seems to vary. In this study, we would like to explore the relationship between three commonly used obesity indicators, WWI (weight-adjusted-waist index), BMI (body mass index), WtHR (waist-to-height ratio), and periodontitis, and try to find the most clinically valuable indicators. The NHANES 2009-2014 provided the data for this study. 10,289, 10,600 and 10,290 participants were included to explore the relationship between WWI, BMI, WtHR and periodontitis respectively. Multiple logistic regression, smooth curve fitting, threshold effects analysis, and subgroup analysis were used to explore their relationships. WWI and periodontitis positively correlated in model III (OR = 1.35; 95% CI, 1.26-1.45, p < 0.001). This result persisted after the quartile for WWI was created. Furthermore, in smooth curve fitting, the relationship between WWI and periodontitis with an inflection point of 12.68 was observed. In the fully adjusted model, WtHR also showed a positive correlation with periodontitis (OR = 2.94; 95% CI, 1.57-5.50, p < 0.001). However, BMI did not express a significant association with periodontitis either as a continuous or categorical variable. This cross-sectional study exposed a positive correlation between WWI, WtHR and periodontitis and this positive correlation showed an age difference.