The Impact of Metabolic Syndrome on Periodontal Treatment Outcomes

Abstract

Background The bidirectional relationship between Metabolic Syndrome (MetS) and periodontal disease is well established. While periodontal therapy has been shown to improve certain MetS parameters, no studies to date have examined the impact of MetS on long-term periodontal treatment outcomes. This study investigated the effect of MetS and its individual components (hypertension, obesity, dyslipidemia, diabetes), as well as clinical and behavioral factors, on periodontal outcomes over five years. Methods In this retrospective longitudinal cohort study, 25,433 patient charts from the Harvard School of Dental Medicine were screened, and 320 met inclusion criteria. Patients were categorized into: Perio-Only (periodontitis without systemic comorbidities), Non-MetS (periodontitis with one or two systemic conditions), and MetS (periodontitis with ≥3 MetS components). Outcomes were evaluated at 6–8 weeks, and at 1, 3, and 5 years post-baseline. The primary outcome was number of residual sites with probing depth ≥5 mm. Results: At 1 year, patients with MetS had 4.75 more residual sites compared to those without MetS (p = 0.006). Differences were not statistically significant at 3 or 5 years, potentially reflecting reduced sample size at later follow-up time points. Dyslipidemia was associated with 3.41 additional residual sites at 1 year (p = 0.043), and obesity (BMI > 25) with 6.40 additional residual sites at 3 years (p = 0.01). Adherence to supportive periodontal therapy was strongly associated with improved outcomes, with compliant patients exhibiting 4.38, 16.62, and 13.66 fewer residual sites at 1, 3, and 5 years, respectively. Greater baseline disease severity was consistently associated with more residual sites over time. Conclusions: MetS and specific systemic components (dyslipidemia and obesity) negatively influence short- and mid-term periodontal treatment outcomes. Adherence to supportive care and baseline disease severity were also strong determinants of long-term results. These findings offer new clinically relevant insights into the oral–systemic connection and lay the groundwork for future prospective studies in this area.