Oral Infections, Metabolic Inflammation, Genetics, and Cardiometabolic Diseases

Area of Science:

• Immunology
• Metabolic Diseases
• Oral Health

Background:

• Epidemiologic studies suggest links between oral infections and cardiometabolic diseases (CMDs), but controversy persists.
• Metabolic inflammation (metainflammation), characterized by low-grade inflammation, is central to obesity, insulin resistance, type 2 diabetes, and CMDs.
• Both metainflammation and oral infections activate the innate immune system via pattern recognition receptors, sharing common inflammatory pathways and cytokines like IL-1β.

Purpose of the Study:

• To explore the potential confounding roles of metabolic inflammation and genetics in the association between oral infections and CMDs.
• To investigate the shared immune pathways activated by oral infections and metainflammation.
• To highlight the need for future research to differentiate independent risks.

Main Methods:

• Review of existing epidemiologic and molecular studies on oral infections, metainflammation, and CMDs.
• Analysis of the roles of pattern recognition receptors (e.g., TLRs, NOD-like receptors) in both conditions.
• Examination of genetic influences on immune responses and CMD development.

Main Results:

• Metainflammation, a hallmark of obesity and related conditions, involves proinflammatory cytokines (e.g., IL-1β) also found in oral infections.
• Both conditions activate innate immunity through similar receptors, suggesting overlapping inflammatory mechanisms.
• Genetics influences immune cell differentiation and CMD susceptibility, creating a complex confounding relationship.

Conclusions:

• The observed association between oral infections and CMDs may be confounded by metabolic inflammation and genetic factors.
• Further research is crucial to determine if oral infections independently contribute to CMD risk.
• Understanding these confounders is essential for accurate risk assessment and targeted interventions.