Effect of Alzheimer’s Disease on Periodontitis

Objectives: Alzheimer’s disease (AD) and periodontitis (P) are associated with systemic pro-inflammatory status and may contribute to each other’s progress. The aim of the study was to evaluate the periodontal status, oral health related quality of life, ApoEε4 allele carrier status, serum vitamin D and IL-18 levels in P patients with (P+AD) and without AD (P-AD).
Methods: Forty three P+AD patients and 40 aged matched P-AD patients were included in this study. Periodontal parameters, number of teeth, geriatric oral health assessment index (GOHAI) and saliva flow rate were recorded. Blood samples were collected and analyzed for the presence of ApoE∈4 and levels of vitamin D and IL-18. ApoE gene polymorphism was carried out by real-time polymerized chain reaction, vitamin D levels by chemiluminescence immunoassay and IL-18 levels by ELISA.
Results: Periodontal parameters and vitamin D levels were similar between P+AD and P-AD groups (p>0.05). Mean vitamin D levels in both groups were consistent with vitamin D deficiency. P+AD group had lower number of teeth, GOHAI score, salivary flow rate, and higher ApoEε4 allele carrier percentage than P-AD group (p<0.05). Moreover, within P+AD group saliva flow rate was lower in ApoEε4 allele carrier patients than non-carrier (p<0.05). Within P-AD group saliva flow rate was lower in patients with low levels of vitamin D than patients with normal levels of vitamin D (p<0.05). Serum IL-18 levels were higher in P+AD group than P-AD group (p<0.05).
Conclusions: This study shows that GOHAI scores were lower in P+AD patients which might be related to low salivary flow rate possibly affected by the ApoEε4 allele carrier and low number of teeth. Moreover, elevated serum IL-18 levels in P+AD patients suggest that IL-18 might play a role in the inflammatory process of AD.