Global environmental and cardiometabolic correlates of periodontitis- ischemic heart disease co-burden: a spatiotemporal network analysis.

BACKGROUND: Geographic co-occurrence patterns and shared risk factors between periodontitis and ischemic heart disease remain inadequately characterized globally. This study aimed to characterize country-level spatiotemporal co-burden patterns of periodontitis and ischemic heart disease, thereby helping identify regions and risk profiles in which integrated periodontal and cardiovascular prevention may be most relevant. METHODS: An ecological analysis was conducted using Global Burden of Disease 2021 data from 204 countries. Machine-learning-based feature selection was used to screen 68 risk factors. Countries were classified as concordant-burden, periodontitis-predominant, or IHD-predominant. Negative binomial regression and population attributable fractions (PAF) quantified risk contributions across 6,528 country-year observations (1990-2021). RESULTS: Periodontitis incidence (1,740.92/100,000) remained 2.2-fold higher than IHD. Analysis revealed 73 countries (35.96%) as IHD-dominant, 74 (36.45%) as periodontitis-dominant, and 56 (27.59%) with dual burdens. Elevated systolic blood pressure was the sole shared risk factor (RR 1.006-1.008). For IHD, insufficient whole grain intake showed the highest attributable fraction (PAF 6.16%), followed by elevated BMI (4.17%) and high LDL cholesterol (3.87%); kidney dysfunction had the strongest per-unit association (RR 1.111) with a PAF of 2.98%. For periodontitis, lead exposure showed the largest model-derived PAF among the assessed factors (PAF 2.36%), followed by blood pressure (2.30%) and particulate matter (1.26%). Disease-specific factors accounted for 20.55% of IHD and 4.51% of periodontitis burden. Temporal analysis revealed strong synchronization in dual-burden regions (ρ=0.901, P<0.001). CONCLUSION: Elevated blood pressure was the only shared population-level factor associated with both conditions. Kidney dysfunction and dietary factors were more strongly associated with IHD burden, whereas lead exposure and particulate matter were associated with periodontitis burden in ecological models. Geographically tailored interventions are essential: metabolic management in IHD-dominant regions and environmental remediation in periodontitis-predominant areas, particularly Eastern Europe, Central Asia, and sub-Saharan Africa. Clinically, the findings support greater attention to blood pressure and cardiometabolic risk assessment in patients with periodontitis, while emphasizing that causal links and intervention benefits require confirmation in individual-level studies.