Effect Modification by Obesity on Nonsurgical Periodontal Treatment

Introduction: Obesity is associated with increased periodontal disease prevalence and incidence. This retrospective cohort study examined whether body mass index (BMI) is an effect modifier of periodontal treatment outcomes in patients attending an urban dental school clinic. Methods: Data were extracted from electronic health records of 344 patients at a large urban dental school clinic who had at least 1 tooth with a probing pocket depth (PD) ≥5 mm at baseline and who subsequently received nonsurgical periodontal treatment. BMI was computed from self-reported weight and height and categorized as obese (≥30 kg/m 2 ), overweight (25–29.9 kg/m 2 ), or healthy (18–24.9 kg/m 2 ). The primary treatment outcome of interest was defined as having no teeth with PD ≥5 mm in a quadrant on follow-up after nonsurgical periodontal therapy. That outcome was considered to represent treatment success in this study. Secondary outcomes included changes in mean PD and clinical attachment loss (CAL). Analyses included 879 treated quadrants among 344 patients (185 males, 159 females; mean age 49 ± 12 y at baseline; mean posttreatment follow-up of 6 ± 2 mo). Clinical outcomes in patients who were overweight or obese were compared to healthy-weight patients using generalized linear models for binary or continuous outcomes, accounting for clustering within patients. Covariates were age, gender, tobacco use, history of diabetes, insurance type, and number of baseline sites ≥5 mm. Results: Obesity was associated with a significantly lower likelihood of successful nonsurgical treatment (odds ratio = 0.47; 95% confidence interval, 0.25–0.88) than healthy weight. Being overweight was not associated with treatment success. Posttreatment reductions in the percentage of sites with pockets ≥5 mm and CAL ≥5 mm were greater in patients with healthy weight as compared to those either overweight or obese. However, posttreatment changes in mean PD and CAL did not differ among the BMI groups. Conclusions: Obesity adversely modifies the effectiveness of nonsurgical periodontal treatment among dental school clinic patients. Knowledge Transfer Statement: The results of this study may be used by dental providers to better understand and manage periodontal therapy in patients with obesity. Furthermore, patients will be better informed about their therapeutic options and outcome success.