Relation of BMI to Periodontal, Microbial and Host Parameters

Objectives: To test the hypothesis that Body Mass Index (BMI) is related to periodontal, microbial and host parameters. Methods: 297 systemically healthy subjects with chronic periodontitis (N=220) or periodontal health (N=77) were recruited. Weight, height, % body fat, BP and smoking status were recorded. Plaque, gingivitis, BOP, suppuration, pocket depth (PD) and attachment level (AL) were measured at 6 sites/tooth. Subgingival plaque samples were taken from the mesial aspect of each tooth and individually analyzed for their content of 40 bacterial species using checkerboard DNA-DNA hybridization (mean samples/subject = 25.6). Levels and % DNA probe counts of each species were determined for each site and averaged across sites in each subject. BMI was computed for each subject and subjects with a BMI >30 were defined as obese (OB) Significance of differences in clinical, microbial and host parameters between OB and non-obese (NOB) subjects was tested using ANCOVA adjusting for age and smoking status.. Results: 12% of periodontally healthy and 30% of periodontitis subects were defined as obese (p < 0.01). OB (N = 75) exhibited significantly greater mean PD, 3.14 ± 0.08 vs 2.83 ± 0.05, p < 0.01; and % of sites exhibiting visible plaque 79±5% vs 65±3%, p < 0.05. Log linear analysis of subjects categorized as OB/NOB, health/periodontitis and current/non smoker supported a strong association (p < 0.01) between obesity and being a periodontitis subject after adjusting for smoking status. OB exhibited higher mean proportions of T. forsythensis than NOB (5.4±0.54 vs 4.0±0.3, p < 0.01). Elevated BMI was also significantly associated with increased age, % body fat and systolic and diastolic BP. Conclusions: OB were more likely to exhibit periodontitis, had a greater mean PD and % sites with plaque and higher proportions of T. forsythensis than NOB. Supported by NIDCR grant DE12861, DE12106, DE14242, DE14368.