Body fat rather than body mass index is associated with gingivitis - A southern Brazilian cross-sectional study

This cross-sectional study aimed to evaluate the association between body mass index (BMI) and body fat with gingivitis in 613 adults of Porto Alegre, Brazil.

Individuals with at least four teeth were included in this study. They were identified through a multi-stage probability sampling, considering the city distribution of sex and age. Structured interviews were conducted by trained researchers in order to collect sociodemographic characteristics, behavioral habits, and systemic impaired conditions. Visible plaque and modified gingival index were assessed by a trained and calibrated examiner. Additionally, weight, height, and body fat percentage were measured. Body fat percentage was determined by bioelectrical-impedance analysis using a portable electrical micro-current monitor. The median sites with marginal bleeding was 20%, and used as a cutoff point for gingivitis. Crude and adjusted prevalence ratio by mean Poisson regression with robust variance were calculated. Two multivariable models were performed in order to associate both independent and dependent variables.

In the multivariable analysis that included BMI, no significant association with gingivitis was detected. On the other hand, the multivariable model that included body fat showed that very high body fat category (PR 1.22; 95% CI: 1.01 to 1.49) was significantly associated with higher marginal gingival bleeding.

Very high body fat category rather than BMI was significantly associated with higher positive marginal gingival bleeding in adults.