Relationship between Obesity Indicators and Gingival Inflammation in Middle-aged Japanese Men

The purpose of this study was to investigate the relationship among the waist-to-height ratio (WHtR) and the body mass index (BMI) as obesity indicators and gingival inflammation as determined by bleeding on probing (BOP). The participants comprised employees of a milk products company based in Tokyo, Japan. A total of 159 non-diabetic men aged 40 to 59 yr and with a minimum of 28 teeth were included. Multiple logistic regression analysis controlling for age, smoking status, pocket depth, frequency of daily brushing, frequency of weekly interdental brushing, and regular dental attendance was performed to compare the relationships among the obesity indicators and BOP. Participants with good oral hygiene had significantly less BOP than those with poor oral hygiene (p<0.001). No significant differences were observed among the other items investigated. A significant association was observed between WHtR and BOP (odds ratio: 2.40, 95% confidence interval: 1.11-5.22); no such association was observed with the BMI, however. The present results showed that obesity, as determined according to a visceral fat index, was associated with BOP, but not with BMI. This suggests that the WHtR is a more accurate index of obesity than the BMI in studies on BOP.