Impact of periodontitis on mortality

Background + Aims

• Periodontitis, a chronic inflammatory disease caused by bacterial plaque, is associated with systemic conditions such as cardiovascular diseases, diabetes, and adverse pregnancy outcomes. It has also been linked to increased mortality risks.
• Among US adults aged 30 and older, periodontitis affects 42%, with 8% experiencing severe forms.
• Access to dental care, crucial for periodontitis management, is often mediated through dental insurance, which improves oral health outcomes and could potentially reduce systemic morbidity and mortality risks. However, prior research has overlooked the role of dental insurance in mitigating these risks.
• This study hypothesises that dental insurance may reduce all-cause mortality and mortality from cardiovascular diseases, diabetes, and cerebrovascular conditions among working-age US adults with periodontitis. Using a conceptual framework, the study aims to explore this association and address the gap in understanding the protective role of dental insurance in systemic health outcomes.

Materials + Methods

• This study utilised data from NHANES III (1988–1994) – a complex, multi-stage survey of the US non-institutionalised population, linked to mortality data up to December 31, 2015.
• The study examined the role of dental insurance in mitigating all-cause and combined mortality (cardiovascular, diabetes, and cerebrovascular diseases) among working-age adults (20–64 years) with periodontitis. Participants with accidental deaths were excluded, yielding 5,914 participants for all-cause mortality analysis and 5,269 for combined mortality.
• Periodontitis was defined as clinical attachment loss (CAL) ≥4mm or probing depth (PD) ≥4mm, while no periodontitis was defined as <4mm for both measures.
• Dental insurance was categorised into private coverage versus no private coverage.
• Confounders included demographic, behavioural, and health need variables, such as sex, age, race, education, tobacco use, BMI, and comorbidities (Charlson Index)
• Statistical analyses, adjusted for NHANES survey design, employed Cox proportional hazard models with follow-up time (person-months) as the time variable.
• Subgroup analyses by periodontal status and sensitivity analyses for unmeasured confounding using e-values were conducted.
• Results were considered significant at p < 0.05.

Results

• The study analysed 5,914 participants for all-cause mortality and 5,269 for combined mortality after exclusions.
• Median follow-up times were slightly longer for participants with periodontitis than without (286 vs. 283 months for all-cause mortality; 290 vs. 285 months for combined mortality).
• All-Cause Mortality:
  • About 62% of participants had periodontitis, with 63% of these having dental insurance. Those with insurance were predominantly aged 35–49, white, college-educated, and urban residents.
  • In participants without periodontitis, dental insurance significantly reduced all-cause mortality hazard in the crude model (HR: 0.53; 95% CI: 0.32, 0.88) and after adjusting for behavioural and need characteristics (HR: 0.55; 95% CI: 0.33, 0.93).
  • Among those with periodontitis, dental insurance consistently reduced all-cause mortality across all models, with a 25% lower hazard in the fully adjusted model (HR: 0.75; 95% CI: 0.61, 0.93).
• Combined Mortality:
  • Around 60% of participants had periodontitis, with 64% having dental insurance. Similar demographic patterns were observed as in all-cause mortality.
  • In participants with periodontitis, only the crude model showed significantly lower combined mortality for those with dental insurance (HR: 0.62; 95% CI: 0.42, 0.91). Adjusted models showed no significant association.
• The e-value analyses suggest that moderate to strong unmeasured confounders could potentially explain the observed associations, particularly for all-cause mortality.

Limitations