Relationship between increases in BMI and changes in periodontal status: a prospective cohort study

The purpose of this prospective cohort study was to investigate whether body mass index (BMI) and oral health behaviour are related to changes in periodontal status in Japanese university students.Students (n = 224) who were interested in receiving oral health examinations before entering university and before graduation were included in the analysis. Subjects were investigated regarding the correlations of oral health behaviours and increases in BMI with the percentage of bleeding on probing (%BOP) and Community Periodontal Index (CPI) scores as indicators of changes in periodontal status.The risk of increased %BOP was associated with the non-use of dental floss (adjusted odds ratio [OR]: 3.11; 95% confidence interval [CI]: 1.31-7.37; p < 0.05), whereas the risk of increased CPI score was associated with increases in BMI (OR: 1.95; 95% CI: 1.05-3.65; p < 0.05) and simplified oral hygiene index score (OR: 2.28; 95% CI: 1.23-4.22; p < 0.01).Increases in BMI were associated with worsening of periodontal status, defined as increased CPI score in Japanese university students, whereas lack of inter-dental cleaning was associated with exacerbated gingival bleeding.