Periodontitis: An often-neglected complication of diabetes

Table 1 The pathobiological interlink between periodontitis and various systemic disorders: The potential mechanisms

Systemic disease	Interlink between periodontitis and the disease	Potential mechanisms
CVD	Accelerated atherosclerosis resulting in ischemic heart disease, stroke, peripheral vascular disease, and heart failure	Aggravation of dyslipidemia, insulin resistance, and endothelial dysfunction from release of various toxic cytokines and microbial products
Pulmonary disorders	Pneumonia caused by systemic spread of pathogens from periodontal tissues; Exacerbation of asthma and COPD from spread of pathogens from mouth; Sleep apnoea with high cytokine load worsens periodontitis	Direct and indirect results of oral microbes on pulmonary diseases and systemic cytokines worsening periodontal inflammation
CKD	CKD can worsen periodontitis and vice versa	Immunological and inflammatory responses from either disease
MAFLD & cirrhosis	Periodontitis can increase insulin resistance and advanced liver disease can worsen periodontal inflammation	Inflammatory mediators such as cytokines and chemokines aggravate either disorder
Obesity	Unhealthy lifestyles lead to obesity and periodontitis	Both diseases have inflammatory pathogenesis and can perpetuate each other
Colitis	Oral and gut microbiota are closely interlinked and can perpetuate disease processes in either region	Inflammatory and immune alterations in gut and periodontal tissues can aggravate both diseases
Rheumatoid arthritis	Inflammation of joints and oral tissues can modulate both diseases	Various humoral and immunological factors and cytokines worsen diseases
Osteoporosis	Pathogenesis of systemic and alveolar bone loss are closely linked	Inflammatory processes in periodontal tissues can potentially impact bone loss
Malignancies	Inflammation in periodontal areas can increase risk of malignancy	Various immunological and inflammatory factors from periodontitis can worsen the risk of cancer
Alzheimer’s disease	Periodontal disease can worsen Alzheimer’s disease and dementia can worsen mouth care and worsen periodontal disease	Increased deposition of β-amyloid and hyperphosphorylation of Tau protein is seen in patients with periodontal disease
Diabetes	Both T1DM and T2DM can worsen periodontitis and periodontitis can worsen glycaemic control	Aggravation of insulin resistance in periodontal disease and poor glycaemic control can worsen oral infections

CVD: Cardiovascular disease; CKD: Chronic kidney disease; COPD: Chronic obstructive pulmonary disease; MAFLD: Metabolic-associated fatty liver disease, T1DM: Type 1 diabetes mellitus, T2DM: Type 2 diabetes mellitus.