ORAL HEALTH STATUS AND PERIODONTITIS IN ALZHEIMER'S DISEASE:A POPULATION-BASED, CASE-CONTROL STUDY FROM THE ZABUT AGING PROJECT

Abstract

Aims. The aetiopathogenesis for Alzheimer's disease (AD) have not been defined, although inflammation within the brain is thought to play a role. Recent data suggest that peripheral infections contribute to the inflammatory state of central nervous system diseases, including cognitive impairment and dementia (1). Periodontitis (PD) is a prevalent, chronic infection involving the tissues supporting the teeth associated with gram negative, anaerobic bacteria capable of promoting local and systemic release of inflammatory mediators. Aim of the present study was to assess the oral health status and the prevalence/severity of PD in incident AD subjects evaluated during a population-based, 10-year follow-up study. Materials and Methods. 10-year follow-up data from the Zabùt Aging Project, a population-based study on dementia and cognitive impairment conducted in a rural sicilian population were used for the present case-control study. From the >1030 subjects evaluated at follow-up, 130 were subjects with incident dementia according to DSM-IV criteria, and 38 were diagnosed with probable AD according to NINCDS-ADRDA criteria. Seventeen (44%) of the latter were totally edentulous and were excluded from this study. Accordingly, the final sample included 21 cases (M: 9; F: 12, age-range 64-93 years) and 21 age- and sex- matched controls (M: 9; F:12; age-range 64-92 years). To evaluate oral health status the Decayed Missed Filled Teeth (DMFT) scoring and measurement of the periodontal probing depth (using Community Periodontal Index –CPI and the Periodontal Screening and Recording Index -PSR) were recorded. The association between AD and oral health indexes was assessed using the χ2 test or t-test as appropriate. A p value ≤0.05 was. considered statistically significant. Results. DMFT average score was similar in AD (18.7±8.0) vs controls (19.2±7.8) (p=0.743). Contrarily, differences between cases and controls groups regarding periodontal status approached statistical significance; indeed, high PSR and CPI scores (>3, indicating moderate-severe PD) were recorded in nearly 78% (n=16) of cases and 48% (n=10) of controls (p= 0.06). Discussion and Conclusions. In this rural Sicilian adult-to elderly community an overall poor oral health was frequent with a high DMFT score. The current data moderately support the hypothesis of a major prevalence and severity of PD among AD patients. To confirm these preliminary results we are currently recruiting a wider sample, including proteomic salivary profiles and RT PCR-based microbiological investigation on sub-gingival plaque samples, in order to better clarify the role of PD and periodontal pathogens in the AD natural history.